WO2025240708A1

WO2025240708A1 - Improved flash spinning process for polyolefins using flash spinning agents comprising a chlorinated solvent and a linear or branched hydrocarbon with 5 to 6 carbon atoms

Info

Publication number: WO2025240708A1
Application number: PCT/US2025/029511
Authority: WO
Inventors: Jan VAN MEERVELD; Martin Schiller
Original assignee: DuPont Safety and Construction Inc
Current assignee: DuPont Safety and Construction Inc
Priority date: 2024-05-17
Filing date: 2025-05-15
Publication date: 2025-11-20
Anticipated expiration: 2026-11-17

Abstract

The present invention relates to (i) a spin fluid for flash spinning comprising (a) at least one polyolefin, and (b) a spin agent comprising at least one chlorinated solvent and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, and (ii) a process for the preparation of plexifilamentary fibrils of polyolefins using the spin fluid.

Description

TITLE

IMPROVED FLASH SPINNING PROCESS FOR POLYOLEFINS USING FLASH SPINNING AGENTS COMPRISING A CHLORINATED SOLVENT AND A LINEAR

OR BRANCHED HYDROCARBON WITH 5 TO 6 CARBON ATOMS

FIELD OF THE INVENTION

The present invention relates to (i) a spin fluid for flashspinning comprising (a) at least one polyolefin, and (b) a spin agent comprising at least one chlorinated solvent and at (east one linear or branched hydrocarbon with 5 to 6 carbon atoms, and (ii) a process for the preparation of plexifilamentary fibrils of polyolefins using the spin fluid.

BACKGROUND

Flash spinning is a process for producing fibrils that involves the following steps: (i) dissolving a polymer in a composition comprising one or more solvents (often called a spin agent), at elevated temperature and pressure to form a homogeneous solution (often called a spin fluid), (ii) reducing the pressure sufficiently below the spin fluid’s cloud point pressure (i.e , the pressure at which the spin fluid transitions from a clear solution to a cloudy, two- phase dispersion), while still maintaining sufficient pressure to prevent the spin fluid from reaching its bubble point pressure (i.e., the pressure at which the spin agent in the spin fluid begins to boil), (iii) releasing the resulting dispersion continuously through one or more orifices into a lower pressure region at or near atmospheric temperature and pressure so that the spin agentflash evaporates as it emerges from the one: or more orifices, (iv) collecting the polymer which remains as a stream of fibrils, e.g., plexifilamentary fibrils, and (v) recovering the evaporated spin agent for re-use. Examples of flash spinning processes are disclosed in US 3,081,519 and US 3,227,794.

In a commercial flash spinning process, the spin agent’s solvent properties and physical properties are critical.: In particular, the solvent properties of the spin agent determine whether and under what conditions fibrils are produced in the flash spinning process, and the spin agent’s physical properties impact the process for recovering and re-using the spin agent. The process for recovering spin agents typically involves a step in which the spin agent is condensed from the gas state to the liquid state, and it is preferred that the composition of the spin agent remains essentially constant during this step. This is inherent when spin agents comprise only one solvent but not when they comprise two or more solvents, which are often required to provide the necessary solvent properties for flash spinning the desired polymer. Accordingly, when using a spin agent that comprises two or more solvents, it is preferred to use a composition that is azeotropic or azeotrope-like which behaves similarly to a spin agent with only one solvent. In many instances, however, it is not practical to use an azeotropic or azeotrope-like composition. For example, when the components of an azeotropic or azeotrope-like spin agent composition are at ratios that do not provide the necessary solvent properties for flash spinning the desired polymer, the spin agent recovery and re-use process becomes significantly more complicated. In such cases, it is instead advantageous to use a composition that is zeotropic.

Examples of solvents that can be used with polyolefins such as polyethylene (PE) are chlorinated solvents, such as dichloromethane (DCM), 1,2-dichloroethylene (DCE) and trichloromethane (TGM). At practical operating temperatures, DCM, DCE, and TGM are each toostrong of a solvent and cannot be used as the only component in a spin agent composition for flash spinning because they dissolve polymers at Watively low pressures. In particular, because DCM, DCE and TGM dissolve polymers at relatively low pressures, the cloud point pressure of a spin fluid using a spin agent with these chlorinated solvents alone is so close to the bubble point pressure that use of such spin agent is not feasible. Weaker solvents such as hydrofluorocarbons can be mixed with DCM, DCE or TGM to reduce the solvent strength of the spin agent and increase the spin fluid’s cloud point pressure such that flash spinning can be readily accomplished.

Other examples of solvents that can be used with polymers such as polyolefins are cyclic C., , hydrocarbons, for example, cyclopentane or cyclohexane. Similar to spin agent systems based on chlorinated solvents, cyclic hydrocarbon solvents are typically blended with other components to adjust the polymer solubility to give a cloud-point pressure of the spin fluid so that flash spinning can be readily accomplished. It is beneficial if such blended hydrocarbon-based spin agents form a homogeneous liquid phase at ambient temperature and pressure, and if they exhibit azeotropic or azeotrope-like behavior at blend ratios which are suitable for flash spinning.

WO 2616/200873 Al suggests spin agent compositions of dichloromethane or 1,2- dichloroethylene with 1H,6H-perfluorohexane, 1 H-perfluorohexane, or 1H-perfluoroheptane. However, use of such linear hydrofluorbcarbons in combination with DCM or DOE results in spin agents that often exhibit undesirably high global warming potential (GWP). In view of the growing concerns regarding climate change and increasing regulatory requirements, there is a need to find suitable tow GWP replacements for spin agent compositions disclosed in the prior art. Such spin agent compositions should also form a homogeneous liquid phase at ambient temperatures and pressures, rather than a heterogeneous liquid phase where, due to low miscibility of the components of the spin agent composition, a liquid-liquid phase separation occurs. Compositions forming heterogeneous liquid phases are usually undesired since processes involving such compositions are more complex and expensive due to the liquid-liquid phase separation.

US 7, 179,413 Bl describes flash spinning of synthetic polymers from a spin agent consisting of a primary spin agent selected from C4-C7 hydrocarbons, chlorinated compounds, fluorinated compounds, and brominated compounds and a co-spin agent which is a fluorinated compound containing 4 to 8carbon atoms and a double bond, and having a boiling point below 100 °C. The presence of fluorinated compounds in these mixtures may still result in an undesirably high global warming potential (GWP).

Accordingly, there is a need for, and the present inventors have discovered, low GWP compositions of at least one chlorinated solvent and at least one hydrocarbon that provide suitable cloud point pressures for flash spinning polyolefins.

The inventors have further discovered that the use of these low GWP compositions for flash spinning polyolefins results in plexifilamentary fibrils having a fine, consistent structure (fibrillation) which can be easily spread and laid down to produce nonwoven sheets with a uniform appearance. Moreover, the flash spun plexifilamentary fibrils prepared as described herein have a high BET surface area arising partly from the presence of many fine fibrils, partly from a rougher surface texture of the plexifilamentary fibrils and partly from internal porosity within these plexifilamentary fibrils. The dimensions of the internal pores of the plexifilamentary fibrils are of similar length-scale as the wavelength in the visible light, and therefore effective to reflect the light. These features all contrioute to light scattering and together provide increased reflectivity and, therefore, increased opacity of the resulting nonwoven sheet. This can be advantageous in a variety of different applications, including, but not limited to, printing applications. SUMMARY OF THE INVENTION

In one embodiment, the invention is directed to a spin fluid for flash spinning comprising (a) from about 9 to about 2S weight percent of a polyolefin, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2- dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

In a further embodiment, the invention is directed to a process for the preparation of plexifilamentary fibrils of polyolefin. The process comprises the steps of:

(i) generating a spin fluid comprising (a) about 9 to about 25 weight percent of a polyolefin, based on the total amount of the spin fluid, and (b) a spin agent, and

(ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the polyolefin, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 shows the cloud point pressure curves of a spin fluid comprising 22 wt% polyethylene (PE) and a spin agent of DCM and n-pentane in a 49.1:50.9 ratio by weight, and of a spin fluid comprising 10 wt% polypropylene (PP) and a spin agent of DCM and n-pentane in a 49.1:50.9 ratio by weight.

Fig 2 shows the cloud point pressure curves of a spin fluid comprising 18 wt% polyethylene (PE) and a spin agent of DCM and 2-methylbutane in a 27 73 ratio by weight, of a spin fluid comprising 20 wt% polyethylene (PE) and a spin agent of DCM and 2-methylbutane in a 35:65 ratio by weight, and of a spin fluid comprising 14 wt% polypropylene (PP) and a spin agent of DCM and 2-methylbutane in a 27:73 ratio by weight.

^; Fig. 3 shows the cloud point pressure curve of a spin fluid comprising 16 wt% polyethylene (PE) and a spin agent of trans-1 ,2-dichloroethylene (trans- 1,2-DCE) and 1-pentene in a 40:60 ratio by weight.

Fig. 4 shows the cloud point pressure curve of a spin fluid comprising 18 wt% polyethylene (PE) and aspin agent of trichloromethane (TGM) and n-hexane in a 46:54 ratio by weight.

Fig. 5 shows the BET surface area as a function of the PE concentration at a constant spin temperature of 200 °C for flash spinning examples 2, 4, 5, and 6, at a constant spin temperature of 185 °C for comparative examples 1 and 5, and at a constant spin temperature of 215 °C for comparative examples 2, 3, and 4.

Fig . 6 shows the BET surface area as a function of the spin temperature at a constant PE concentration of 18 wt% for flash spinning examples 1, 2, and 3 and at a constant PE concentration of 10 wt% for comparative examples 1 and 2. . DETAILED DESCRIPTION

Definitions and Clarification of Terms

Before addressing details of embodiments, some terms and test methods are defined or clarified. Unless otherwise mentioned, all tests were carried out without preconditioning of the samples. When average values are indicated herein, this refers to the arithmetic average.

Density is determined according to the method described in ISO 1183 (Plastics - Methods for determining the density of non-cellular plastics).

Melting temperature is determined by differential scanning calorimetry, following the guidance provided in ASTM 03418 (Standard Test Method for Transition Temperatures and Enthalpies of Fusion and Crystallization of Polymers by Differential Scanning Calorimetry) and ASTM Standard F2625 (Standard Test Method for Measurement of Enthalpy of Fusion, Percent Crystallinity and Melting Point of Ultra-High-Molecular weight polyethylene by means of differential scanning calorimetry). For polyethylene, heating and cooling is performed under inert gas at a rate of 10 'C/minute, heating the sample first tom room temperature to 210 °C, then cooling the sample back to room temperature and subsequently heating the sample a second time to 210 ' C The melting point reported herein is the peak temperature of the endotherm of the second heating cycle For polypropylene, the same procedure applies - where the maximum temperature is 230 °C. For poly-4-methyi-1 -pentene, the same procedure applies -where the maximum temperature is 300 °C. The melt flow rate is determined according to the method described in ISO 1133 (Plastics - Determination of the melt mass-flow rate (MFR) and the melt volume-flow rate (MVR) of thermoplastics). The melt flow rate for polyethylene is determined under condition “D” at a temperature of 190 °C and using a mass of 2160 grams (2.16kg) or 21 ,600 gram (21.6kg), The melt flow rate for polypropylene is determined at a temperature of 230 °C and using a mass of 2160 grams (2.16kg). The melt flow rates of other polyolefins are performed at different temperatures as specified in IS0 1133.

BET surface area is measured by the BET nitrogen absorption method of S. Brunauer, P H. Emmett and E. Teller, J. Am. Chem. Soc., V. 60 p 309-319 (1938) based on 5 equidistant relative pressures between 0.1 to 0.25 and is reported as m²/g. The samples measured have a total surface area above 2 m². BET surface area is measured using a Quantachrome model .

NOVA 3000e from Quantachrome GmbH, Odelzhausen, Germany. Performance of the equipment is verified by using a standard aluminum oxide sample (3P-SRF586) having a BET surface area of 5.86 +/- 0.23 m²/gram supplied by 3P Instruments GmbH & Co, Odelzhausen, Germany. Before measurement, the samples are dried for at least 2 hours at a temperature of 60°C under vacuum on equipment Degasser MasterPrep from Quantachrome GmbH, Odelzhausen, Germany. The BET surface area reported herein is based on 1 or 2 measurements.

The fiber web quality is determined based oh a visual inspection of flash spun webs.

A tie-point is where the individual fibrils are connected, split or merge - the tie-points connect the individual fibrils to form a web. A rating of “fine” refers to a web having individual fibrils which are uniform and fine in size with a uniform distance between the tie-points. This allows the web to be opened into a uniform, fine, net-like structure without large holes or gaps, and without thick fibrils or agglomerations of fibrils which cannot be opened. This structure is desired to enable the webs to be distributed into a nonwoven sheet having a uniform coverage of fibrils. A rating of "coarse" indicates that thicker fibrils are present , that the distance between tie-points is larger, or that the structure of the web is uneven . One or more of these features may be present at the same time. This results in a web which is difficult to open and which contains larger holes or gaps, and/or thick fibrils or agglomerations of fibrils which cannot be opened. A rating of “yam-ike" indicates that individual fibrils are present but that they are connected along much of their length and/or with such closely spaced tie-points that it is nearly impossible to open the web.

The term “hydrocarbon" is intended to embrace, without limitation, saturated hydrocarbons (such as, for example, 2-methylbutane or hexane) as well as unsaturated hydrocarbons (such as, for example, 1-pentene, 2-methyl-2-butene, 2-methyM -butene or 1- hexene). The hydrocarbon may contain minor amounts of one or more other linear and/or cyclic hydrocarbons with 5 to 7 carbon atoms, such as cyclopentane, methylcyclopentane, 1 ,3-dimethylcyclopentane, cyclohexane, and/or methylcyclohexane. The total amount of the other hydrocarbon(s) present in the hydrocarbon shall not exceed 10 weight percent, or 5 weight percent i The term “polymer” is intended to embrace,, without limitation, homopolymers, copolymers (such as for example, block, graft, random, and alternating copolymers), terpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer" shall include all possible geometrical configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and random symmetries.

The term “polyethylene” is intended to embrace not only homopolymers of ethylene, but also copolymers and terpolymers wherein at least 85% of the recurring units are ethylene units, and the comonomer unit is, for example, propylene, butylene, hexene or octene. One useful polyethylene is a polyethylene that has a melting temperature of about 123 °C to about 140 °C, a density in the range of 0.94 to 0.98 grams per cubic centimeter (ISO 1133), and a melt flow rate (ISO 1133, 190 °G/2160 grams) of between 0.05 g/IOmin and 30 g/10min, preferably less than 4 g/I Omin, and/or a melt flow rate (IS0 1133, 190 °C/21 ,600 grams) of between 1 g/10min and 15 g/10min, the term “polypropylene” is intended to embrace not only homopolymers of propylene but also copolymers and terpolymers where at least 85% of the recurring units are propylene units. Furthermore, unless otherwise specifically limited, the term "polypropylene" shall include all possible geometrical configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and random symmetries.

The term "polymer type’’ refers to the chemical class into which the polymer falls, for example, polyolefin, polyethylene, polypropylene, etc. The term “plexifilamentary” refers to a three-dimensional integral network or web of a multitude of thin, ribbon-like, fibrils of random length and a median fibril width of less than about 25 microns, in plexifilamentary structures, the fibrils are generally coextensively aligned with the longitudinal axis of the structure, and they intermittently unite and separate at irregular intervals in various places throughout the length, width, and thickness of the structure to form a continuous three-dimensional network or web.

The terms “spin agent” or "spin agent composition* refer to a composition comprising one or more solvents and any additives that are used to initially dissolve the polymer(s) to form the spin fluid, Suitable additives include stabilizers, such as antioxidants or acid scavengers. The term "spin fluid” refers to a solution for spinning in a flash spinning process comprising a polymer and a spin agent. The solution may also include one or more additives

The term dew point pressure” refers to the pressure at which, at constant temperature, liquid starts condensing from a vapor, vapor mixture, or vapor-gas mixture. ^;

The term "bubble point pressure” refers to the pressure at which, at constant temperature, a liquid, liquid mixture, or liquid-solution begins to boil

The term "azeotropic composition refers to a composition comprising two or more fluids wherein the bubble point pressure equals the dew point pressure. An azeotropic composition boils without change of the composition and behaves as a single substance.

The term ‘‘non-azeotropic composition," also referred to as “zeotropic composition,” refers to a composition comprising two or more fluids that behaves as a mixture rather than a single substance over the whole composition range upon boiling. In a non-azeotropic composition, the bubble point pressure is substantially different from the dew point pressure over the entire composition range, and the components can be separated completely into pure substances by distillation. The non-azeotropic compositions described herein, unless expressly stated otherwise, are determined at 40 °C and expressed in mass fractions. The term “cloud point pressure” refers to the pressure at which, at constant temperature, a clear single phase spin fluid tfansitions tom a clear solution to a cloudy, two- phase dispersion. At the cloud point pressure, a clear spin fluid becomes turbid.

Atmospheric pressure means 101 325 kPa Essentially atmospheric pressure means 101.325 kPa ± 5 %.

As used herein, the singular forms "a,” "an," and "the" indude the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. When a range of values is expressed, another embodiment includes tom the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment All ranges are inclusive and combinable.

Spin Agents and Spin Fluids for Flash Spinning

Provided herein are spin fluids for flash spinning polyolefins. The spin fluid comprises (a) tom about 9 to about 25 weight percent of a polyolefin, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises, consists essentially of or consists Of a composition comprising at least one chlorinated solvent, selected tom dichloromethane, trans-1 ,2-dichloroethylene, cis- 1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

In some embodiments, the spin fluid comprises tom about 75 to about 91 weight percent of the spin agent,, based on the total amount of the spin fluid .

In some embodiments, the spin fluid comprises (a) tom about 10 to about 25 weight percent of a polyethylene, based on the total amount of the spin. fluid, and (b> a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected tom dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trlchioromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, m other embodiments, the spin fluid comprises (a) tom about 12 to about 20 weight percent of a polyethylene, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1, 2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) tom about 9 to about 16 weight percent, or from about 9 to about 11 weight percent, of a polyethylene, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane , trans-1,2-dichloroethylene, cis- 1,2* dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, in other embodiments, the spin fluid comprises (a) from about 15to about 25 weight percent, or from about 18 to about 25 weight percent, of a polyethylene based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2*dichloroethylene, cis»1,2*dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

In some embodiments, the spin fluid comprises from about 75 to about 91 weight percent of the spin agent, based on the total amount of the spin fluid, in other embodiments, the spin fluid comprises from about 75 to about 90 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 80 to about 88 weight percent of the spin agent, based on the total amount of the spin fluid In some embodiments, the spin^:fluid comprises from about 84 to about 91 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 89 to about 91 weight percent of the spin agent, based bn the total amount of the spin fluid. In some embodiments, the spin fluid comprises from about 75 to about 85 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 75 to about 82 weight percent of the spin agent, based on the total amount of the spin fluid

In some embodiments, the spin fluid comprises (a) from about 10 to about 25 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1- pentene), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethahe, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) from about 10 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1- pentene), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane , trans- 1 ,2-dichloroethy lene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to & carbon atoms. In other embodiments, the spin fluid comprises (a) from about 10 to about 15 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1- pentene), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) from about 15 to about20 weight percent of a polyolefin, selected from a polypropylene, a poiybutene-1. or a poly(4 -methyl- 1- pentehe), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1, 2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

In some embodiments, the spin fluid comprises from about 75 to about 91 weight percent of the spin agent, based on the total amount of the spin fluid, in other embodiments from about BQ to about 90 weight percent of thespin agent, based on the total amount of the spin fluid, in other embodiments from about 85 to about 90 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 80 to about 85 weight percent of the spin agent, based on the total amount of the spin fluid.

In some embodiments, the at least one linear or branched hydrocarbon with 5 to 6 carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyt-1 -butene, and 1-hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane , n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, and 1-hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of cis-1.2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consistir^i of n-pentane, 1-pentene, 2-methylbutane, n-hexarie,

2-methylpentane, 3-methylpentane, 2,2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, and 1-hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of trans-1 , 2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n- hexane, 2-methylpentane, 3-methylpentane. 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of trans-1 , 2-dichloroethylene and cis-1 , 2-dichloroethylene and at least one linear or branched hydrocarbon with 5/ to 6 carbon atoms selected from the group consisting of n-pentane, 1- , pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atom s selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane. n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, and 1 -hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis- 1, 2-dichloroethylene, and trichioromethane, and from about 99 to about 40 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane^ 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-^ dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to abouW5 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1, 2-dichloroethylene, and; trichioromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1-butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1.2-dichloroethylene. cis-1 ,2-dichloroethylene. and trichioromethane, and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane. n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1, 2-dichloroethylene, and trichioromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene. Insome embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane. , in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 1 to about 70 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-

1 , 2-dichloroethylene, and trichioromethane, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1-butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 , 2-dichloroethylene, cis-1, 2-dichloroethylene, and trichioromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 , 2-dichloroethylene, cis-

1 , 2-dichloroethylene, and trichioromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with

5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene. and 2-methyl-1 -butene. in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of or consists of from about 20 to about 48 weight percent of dichloromethane and from about 80 to about 52 weight percent of 2-methylbutane

In some embodiments, the spin agent comprises, consists essentially of. or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent Of at least one chlorinated solvent selected from dichloromethane. trans-1 _; 2-dichloroethylene. cis-

1 , 2-dichloroethylene, and trichioromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane. 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1 -hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2- _; dichloroethylene, cis-1 ,2-dichloroethylene, and trichioromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-peritane, 1-peritene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, and 1 -hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichioromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene_i 2-methyl-1-butene, and 1-hexene. in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichioromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 45 weight percent of at least one chlorinated solvent, selected from dichioromethane, transit ,2-dichloroethylene, cis^ 1 ,2-dichloroethylene, and trichioromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with _: 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichioromethane, trans-1, 2-dichloroethylene, cis-1,2- dichloroethylene. and trichioromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichioromethane, trans-1, 2-dichtoroethylene, cis-1,2-diChloroethylene, and trichioromethane, and from about 85 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2- butene, and 2-methyl-1-butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichioromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 20 to about 48 weight percent of dichloromethane and from about 80 to about 52 weight percent of 2-methylbutane.

In some embodiments, the spin agent comprises or consists essentially of an azeotropic or azeotrope-like composition composing dichloromethane and n-pentane. or an azeotropic or azeotrope-like composition comprising dichloromethane and 3-methylbutane. or an azeotrope-like composition comprising trichloromethane and n-hexane.

In some embodiments, toe azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent n-pentane, or from about 31 to about 70 weight percent dichloromethane and from about 69 to about 30 weight percent n-pentane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °G to about 100 “C and at a boiling pressure of about 10 kPa to about 703 kPa. In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane, These azeotropic or azeotrope-like compositions boit at a temperature of about 40 °C and at a boiling pressure of about 132 kPa to about 439 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 43 to about 58 weight percent dichloromethane and from about 57 to about 42 weight percent n-pentane. These azeotropic compositions boil at a temperature of about - 20 °C to about 100 °G and at a boiling pressure of about 11 kPa to about 703 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 50.9 weight percent dichloromethane and about 49.1 weight percent n-pentane at a pressure of about 82 kPa and at a boiling temperature of about 25 °C. In some embodiments, the azeotropic composition consists essentially of or consists of about 51.0 weight percent dichloromethane arid about 49.0 weight percent n-pentane at a pressure of about *138.9 kPa and at a boiling temperature of about 40 C. In some embodiments, the azeotropic composition consists essentially of or consists of about 49 8 weight percent dichloromethane and about 50.2 weight percent n-pentane at a pressure of about 101.3 kPa and at a boiling temperature of about 30,8 °C.

In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent 2-methylbutane, or from about 24 to about 70 weight percent dichloromethane and from about 76 to about 30 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 13 kPa to about 775 kPa. In some embodiments, toe azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 15 to about 56 weight percent dichloromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 Weight percent dichioromethane and from about 75 to about 49 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about 40 °C and at a boiling pressure of about 157 kPa to about 163 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 26 to about 42 weight percent dichioromethane and from about 74 to about 58 weight percent 2-methylbutane.

These azeotropic compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 14 kPa to about 775 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 35.0 weight percent dichioromethane and about 65.0 weight percent 2-methylbutane at a pressure Of about 162.6 kPa and at a boiling temperature of about 40 "C. in some embodiments, the azeotropic composition consists essentially of or consists of about 33.1 weight percent dichioromethane and about 66.9 weight percent 2-methylbutane at a pressure of about 101.3 kPa and at a boiling temperature of about 25.7 °C. In some embodiments, the azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 60 weight percent trichtoromethane and from about 40 to about 99 weight percent n-hexane, or from about 46 to about 60 weight percent trichtoromethane and from about 54 to about 40 weight percent mhexane These azeotrope- like compositions boil at a temperature of about 20 °C to about 100 °C and at a boiling pressure of about 20 kPa to about 315 kPa. in some embodiments, the azeotrope-like composition consists essentially of or consists of about 46 to about 60 weight percent trichloromethane and about 54 to about 40 weight percent n-hexane at a pressure of about 45 to 48 kPa and at a boiling temperature of about 40 C

The spin fluid may include additives, such as antioxidants or acid scavengers, in minor amounts. In some embodiments, the spin fluid comprises additives in an amount of about 1 .5 weight percent or less of the total amount of the spin agent, and in other embodiments in an amount of about 0.1 weight percent or less of the total amount of the spin agent.

The spin agent can be used for a broad range of different polyolefins and blends/mixtures thereof. In some embodiments, polyolefins are > polyethylene (PE), polypropylene (PP), polybutene- 1 (PB-1 ), poly(4-methyl-1 -pentene) (PMP), and blends/mixtures thereof. Particularly preferred polyolefins are polyethylene (PE), in particular high-density polyethylene (HOPE), and blends/mixtures of high-density polyethylene (HDPE) and low-density polyethylene (LDPE), in particular linear low-density polyethylene (L.LDPE). In some embodiments, the polyolefin is a high-density polyethylene (HOPE).

In some embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, Wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-

1.2-dichloroethylene, : cis-1 ,2-dichloroethylene, and trichloromethane, , and from about 99 to about 40 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-, dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-i-butene, and 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloft3ethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2.3-dimethylbutane, 2-methyl-2-butene. 2-methyl-1 -butene, and 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-

1 .2-dichloroethylene, cis-1 , 2 -dichloroethylene, and trichloromethane, and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, and 1-hexene,

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane, In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid,, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 70 weight percent, or from about 20toabout 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1-butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent selected from dichloromethane. trans-1,2-dichloroethylene, cis-1.2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of ri- pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene. In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 Weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 15 to about 56 weight percent or from about 25 to about 51 weight percent of dichloromethane and from about 85 to about 44 weight percent or from about 75 to about 49 weight percent of 2-methylbutane.

In some embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a^ polyolefin, selected from a polypropylene, a polybutene»1, or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 40 Weight percent, or from about 10 to about 40 weight percent of at least one chlorinated solvent, ‘selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1. or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-didiloroethytene, cis-1,2- dichloroethylene, and trichloromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-penterie, 2-methylbutane, n-hexane, 2-methylperitane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene. In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of , or consists of from about 30 to about 60 weight percent of dichlorometharie and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane. In some embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 5 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1-butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about ^: 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2- dichioroethylene, and trichloromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene. 2-methylbutane. 2-methyl-2-butene, and 2-methyl-1 -butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 85 to about 70 weight percent of atfeast one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about I S weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl- 1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 15 to about 56 weight percent or from about 25 to about 51 weight percent of dichloromethane and from about 85 to about 44 weight percent or from about 75 to about 51 weight percent of 2-methylbutane.

In some embodiments, the spin fluid comprising the composition as described herein exhibits a cloud point pressure in the range of about 45 to about 300 bar , in other embodiments in the range of about 50 to about 300 bar, and in other embodiments in the range of about 70 to about 300 bar In some embodiments, the spin fluid ; comprising the composition as described herein exhibits a cloud point pressure in the range of about 45 to about 250 bar, in other embodiments in the range of about 50 to about 250 bar, and in other embodiments in the range of about 70 to about 250 bar. In some embodiments, the spin fluid comprising the composition as described herein exhibits a cloud point pressure in the range of about 45 to about 200 bar, in other embodiments in the range of about 50 to about 200 bar, and in other embodiments in the range of about 70 to about 200 bar. The flash spinning process must take place at an operating pressure below the spin fluid’s cloud point pressure but above the spin fluid's bubble point pressure. If the pressure becomes lower than the spin fluid’s bubble point pressure, premature and unwanted boiling occurs If the cloud point pressure is above about 300 bar, the flash spinning equipment must be built to withstand very high pressure which increases costs and operational constraints.

Properties of the spin fluids comprising the spin agent compositions

The compound dichloromethane (DCM) has a reported GWP-100 (global warming potential over a 100-year period) of 11.2 (IPCC 2021 report) and the compound trichloromethane (TCM, chloroform) has a reported GWP-100 of 20.6 (IPCC 2021 report). No calculated GWP value Is? available for trans-W-dichlQroethylene and for cis-1,2- dichloroethylene. However, these compounds are expected to have short atmospheric lifetimes due to their relatively high reactivity, so a very low GWP-100 of essentially zero may be assumed. While no specific data is available for linear or branched hydrocarbons, such as n-pentane, 1-pentene, 2-methylbutane, hexane, 2-methyipentane, 3-methylpentane, 2,2- dimethylbutane, 1 -hexene, 2-methyl-2-butene, and 2-methyl-l-butene, and 2,3- dimethylbutane, values reported for hydrocarbons with up to four carbon atoms show a rapid decline in GWP-100 as the number of carbon atoms increases, so it is reasonable to assume a GWP-100 of at or close to zero for these compounds. )

Accordingly, the spin agent compositions disclosed herein combining the chlorinated compounds dichloromethane, trichloromethane, and/or dichloroethylene and one or more of linear or branched hydrocarbons with 5 to 6 carbon atoms have a very low global warming potential (GWP). In some embodiments, spin agent compositions comprising trans/cis-1,2- dichloroethylene and one or more of linear or branched hydrocarbons with 5 to 6 carbon atoms have a GWP-100 of at or close to zero.

The spin agent compositions as described herein have the advantage of being homogeneous compositions. For homogenous spin agent compositions, the components of the composition at ambient temperatures and pressures form a single liquid phase This is to be contrasted with heterogeneous spin agent compositions where, due to low miscibility of the components of tie composition, the components of the composition undergo phase separation in the liquid phase. Phase separation is usually undesired since processes involving the composition are more complex and expensive. The homogeneous nature of the spin agent compositions is achievable over a broad range of practical conditions including ambient pressure and temperature.

Preparation of Plexifilamentary Fibrils of Polymer

In some embodiments, there is provided a process for the preparation of plexifilamentary fibrils of polyolefin. The process comprises the steps of'

(i) generating a spin fluid comprising

(a) about 9 to about 25 weight percent of a polyolefin, based on the total amount of the spin fluid, and ^? (b) a spin agent, and

(ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the polyolefin, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

In some embodiments, the flash-spinning is performed at a pressure in the range of about 45 to about 300 bar, in other embodiments in the range of about 50 to about 300 bar, or in other embodiments in the range of about 70 to about 300 bar. In some embodiments, the flash-spinning is performed at a pressure in the range of about 45 to about 250 bar, in other embodiments in the range of about 50 to about 250 bar, and in other embodiments in the range of about 70 to about 250 bar. In some embodiments, the flash-spinning is performed at a pressure in the range of about 45 to about 200 bar, in other embodiments in the range of about 50 to about 200 bar, and in other embodiments in the range of about 70 to about 200 bar. The region of lower pressure into which flash spinning occurs is usually at or around atmospheric pressure.

In some embodiments, the spin fluid comprises from about 75 to about 91 weight percent of the spin agent, based on the total amount of the spin fluid.

In some embodiments, the spin fluid comprises (a) from about 10 to about 25 weight percent of a polyethylene, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane. trans-1.2-d>chloroethylene. cis-1.2-^: dichloroethylene, and tfichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms In other embodiments, the spin fluid comprises (a) from about 12 to about 20 weight percent of a polyethylene, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) from about 9 to about 16 weight percent, or from about 9 to about 11 weight percent, of a polyethylene, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-l ,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) from about 15 to about 25 weight percent, or from about 18 to about 25 weight percent, of a polyethylene, based oh the total amount of the spin fluids and (b| a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1, 2-dichloroethyiene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

In some embodiments, the spin fluid comprises from about 75 to about 91 weight percent of the spin agent, based on the total amount of the spin fluid, in other embodiments, the spin fluid comprises from about 75 to about 90 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 80 to about 88 weight percent of the spin agent, based on the total amount of the spin fluid. In some embodiments, the spin fluid comprises from about 84 to about 91 weight percent of the spin agent, based on the total amount of the spinfluid, and in other embodiments from about 89 to about 91 weight percent of the spin agent, based on the total amount of the spinfluid. In some embodiments, the spin fluid comprises from about 75 to about 85 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 75 to about 82 weight percent of the spin agent, based on the total amount of the spin fluid.

In some embodiments, the spin fluid comprises (a) from about 10 to about 25 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a polyC^methyl-i- pentene), based on the total amount of the spin fluid, and (b)a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at ieast one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethyiene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms In other embodiments, the spin fluid comprises (a) from about 10 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1- pentene), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans^l, 2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) from about 10 to about 15 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1- pentene), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1, 2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In other embodiments, the spin fluid comprises (a) from about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a po|y(4-methyl-1- pentene), based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises or consists essentially of a composition comprising at least one chlorinated solvent, selected from dichloromethane, trans-1 , 2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethahe, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms. In some embodiments, the spin fluid comprises from about 75 to about 91 weight percent of the spin agent, based on the total amount of the spin fluid, in other embodiments from about 80 to about 90 weight percent of the spin agent, based on the total amount of the spin fluid, in _: other embodiments from about 85 to about 90 weight percent of the spin agent, based on the total amount of the spin fluid, and in other embodiments from about 80 to about 85 weight percent of the spin agent, based on the total amount of the spin fluid.

In some embodiments, the at least one linear or branched hydrocarbon with 5 to : 6 carbon atoms is selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2- methyl-2-butene, 2-methyl-1-butene, and 1-hexene In some embodiments, the spin agent comprises, consists essentially of, or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2* butene, 2-methyl-l -butene, and 1-hexene. in some embodiments, the spin agent comprises, consists essentially of, or consists of cis-1 , 2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane. 1 -pentene, 2-methylbutane, n-hexane. 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, Or consists of trans-1 , 2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane 1 -pentene, 2-methylbutane. n- hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2- methyl-2-butene, 2-methyl-1 -butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of trans- 1, 2-dichloroethylene and cis-1 , 2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1- pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2*methyl-2- butene, _:2-methyl-1 -butene, and 1 -hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-

1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 40 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene. 2- methyibutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyi-l-butene, and 1-hexene. in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis*1, 2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methy 1-1 -butene, and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at feast' one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at feast one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene. and 1-hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 , 2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2, 3-dimethyibutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about l to about 70 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis* 1,2-dichloroethylene, and trichloromethane, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon With 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methytbutane, 2-methyl-2-butene, and 2-methyi-1 -butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethy lene, cis- 1 ^2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected 'from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis- 1,2-dichloroethylene, and trichloromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-l -butene, In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 20 to about 48 weight percent of dichloromethane and from about 80 to about 52 weight percent of 2-methylbutane.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene. cis- 1 ,2-dichloroethylene, and trichloromethane. and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, and 1 -hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2- dichloroethylene, cis-1 ,2-dichloroethylene, ano trichloromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of ; n-pentane, 1-pentene, 2-methylbutane, < n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, _:2-methyl-1 -butene, and 1 -hexene.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about "70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyM -butene, and 1 -hexene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane.

In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 45 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis- 1 ,2-dichloroethylene, arid trichloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene. in some embodiments, the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about

20 to about 50 weight percent, or from about 30 to about 50 weight percent Of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane. 1 -pentene, 2-methylbutane. 2-methyl-2-butene. and 2-methyi-1 -butene. In some embodiments, the spin agent comprises, consists essentially of. or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1, 2-dichloroethylene, and trichloromethane, and from about 85 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2- butene, and 2-methyl-1 -butene. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 20 to about 48 weight percent of dichloromethane and from about 80 to about 52 weight percent of 2-methylbutane. In some embodiments, the spin agent comprises or consists essentially of an azeotropic or azeotrope-like composition comprising dichloromethane and n-pentane, or an azeotropic or azeotrope-like composition comprising dichloromethane and 3-methylbutarie, dr an azeotrope-like composition comprising trichloromethane and n-hexane. In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent n-pentane, or from about 31 to about 70 weight percent dichloromethane and from about 69 to about 30 weight percent n-pentane. These azeotropic or azeotrope-like _: compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 10 kPa to about 703 kPa In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane. These azeotropic or azeotrope-like compositions boil at a temperature of about 40 °C and at a boiling pressure of about 132 kPa to about 139 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 43 to about 58 weight percent dichloromethane and from about 57 to about 42 weight percent n-pentane. These azeotropic compositions boil at a temperature of about - 20 °C to about 100 °C and at a boiling pressu re of about 11 kPa to about 703 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 50.9 weight percent dichloromethane and about 49.1 weight percent n-pentane at a pressure of about 82 kPa and at a boiling temperature of about i 25 °C. i In some embodiments, the azeotropic composition consists essentially of or consists of about 51.0 weight percent dichloromethane and about 49 0 weight percent n-pentane at a pressure of about 138.9 kPa and at aboiling temperature of about 40 °C. In some embodiments, the azeotropic composition consists essentially of or consists of about 49.8 weight percent dichloromethane and “about 50.2 weight percent n-pentane at a pressure of about 101.3 kPa and at a boiling temperature of about 30.8 °C.

In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent 2-methylbutane, or from about 24 to about 70 weight percent dichloromethane and from about 76 to about 30 weight percent 2-methylbutane. These azeotropic or azeotrope-like compositions boil at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 13 kPa to about 775 kPa. In some embodiments, the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 15 to about 56 weight percent dichloromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 weight percent “dichloromethane and from about 75 to about 49 weight percent 2-methylbutane, These azeotropic or azeotrope-like compositions boil at a temperature of about 40 °C and at a boiling pressure of about 157 kPa to about 163 kPa. In some embodiments, the azeotropic compositions comprise, consist essentially of, or consist of from about 26 to about 42 weight percent dichloromethane and from about 74 to about 58 weight percent 2-methylbutane. These azeotropic compositions boil at a temperature of about -20 ’ C to about 100 °C and at a boiling pressure of about 14 kPa to about 775 kPa. In some embodiments, the azeotropic composition consists essentially of or consists of about 35.0 weight percent dichloromethane and about 65,0 weight percent 2-methylbutane at a pressure of about 162.6 kPa and at a boiling temperature of about 40 °C. In some embodiments, the azeotropic composition consists essentially of or consists of about 33.1 weight percent dichloromethane and about 66 9 weight percent 2-methylbutane at a pressure of about 101.3 kPa and at a boiling temperature of about 25.7 °C.

In some embodiments, the azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 60 weight percent frichloromethane and from about 40 to about 99 weight percent n-hexane, or from about 46 to about 60 weight percent frichloromethane and from about 54 to about 40 weight percent n-hexane. These azeotropelike compositions boil at a temperature of about 20 °C to about 100 °C and at a boiling pressure of about 20 kPa to about 315 kPa. In some embodiments, the azeotrope-like composition consists essentially of or consists of about 46 to about 60 weight percent trichloromethane and about 54 to about 40 weight percent n-hexane at a pressure of about 45 to 48 kPa and at a boiling temperature of about 40 C.

The spin fluid may include additives such as antioxidants or acid scavengers, in minor amounts. In some embodiments, the spin fluid comprises additives in an amount of about 1.5 weight percent or less of the total amount of the spin agent, and in other embodiments in an amount of about 0.1 weight percent or less of the total amount of the spin agent.

The spin agent can be used for a broad range of different polyolefins and bfends/mixtures thereof.

In some embodiments, polyolefins are polyethylene (PE), polypropylene (PP), polybutene-1 (PB-1 ), poly(4-methyl-1-pentene) (PMP), and blends/mixtures thereof. Particularly preferred polyolefins are polyethylene (PE), in particular high-density polyethylene

(HOPE), and blends/mixtures of high-density polyethylene (HOPE) and lbw-density polyethylene (LDPE), in particular linear low-density polyethylene (LLDPE). In some embodiments, the polyolefin is a high-density polyethylene (HOPE). tn some embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 99 to about 40 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 •pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyi-1-butene, and 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at feast one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1 ,2-dichloroethylene, and frichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyi-2-butene, 2-methyi-l-butene, and 1 -hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected- from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or abouts to about 11 weightpercent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 _: to about 70 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 30 weight percent, or from about 80 to a bout 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-l-butene,

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin ^; agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting; of n- pentane, 1 -pentene, 2-methylbutane, 2-methy|-2-butene, and 2-methyl-l-butene. In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 1 1 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about

30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-l -butene,

, In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 15 to about 56 weight percent or from about 25 to about 51 weight percent of dichloromethane and from about 85 to about 44 weight percent or from about 75 to about 49 weight percent of 2-methylbutane.

In some embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentahe, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, ^: Wherein the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 , 2- dichloroethylene, and trichloromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, arid 1-hexene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 io about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane.

In some embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 Weight percent of a _: polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 45 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-l-butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a poly olefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-l -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially Of, or consists of from about 10 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 90 to about 50 weight percent, orfrom about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyt-2-butene, and 2-methyl-1 -butene.

In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, or a poly(4-methyl-1-pentene), each based on the total amount of the spin .fluid,; and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichioromethane, trans- 1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 85 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl»1- butene. < ^; In other embodiments, the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent Of a polyolefin, selected from a polypropylene, a polybutene- 1 or a poly(4-methyl-1 -pentene). each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. In some embodiments, the spin agent comprises, consists essentially of, or consists of from about 15 to about 51 weight percent er from about 25 to about 51 weight percent of dichloromethane and from about 85 to about 49 weight percenter from about 75 to about 51 weight percent of 2-methylbutane.

In some embodiments, there is provided plexifilamentary fibrils of polyolefin obtainable by the process described herein.

In some embodiments, the plexifilamentary fibrils obtainable by the process described herein are characterized in that the BET Surface areals from about 5 to about 60 m^g, or from about 10 to about 60 m^g, or from about 15 to about 60 m²/g, or from about 20 to about 60 m²/g, or from about 25 to about 60 m²/g, or from about 30 to about 60 m²^, or from about 45 to about 60 m²/g. In some embodiments, the plexifilamentary fibrils obtainable by the process described herein are characterized in that the BET surface area is from about 13 to about 40 m²/g or from about 13 to about 30 m²/g, or from about 13 to about 20 m²/g.

In some embodiments, the plexifilamertary fibrils obtainable by the process described herein have a fine, consistent structure (fibrillation). This leads to a very uniform appearance of the nonwoven sheet.

The shape of the assembly of plexifilamentary fibrils of polyolefin discharged from each spin orifice may be modified by any methods known in the art. In some embodiments, the plexifilamentary fibrils of polyolefin discharged from each spin orifice may be modified by passing into a shroud such as described on US 3.387.326. in other embodiments by passing into a slotted outlet such as described in US 3.467.744 or US 5.788.993, and in other embodiments passing into a slot fan jet as described in US 8.114 325. In some embodiments, streams of fibrils from multiple orifices may exit via a common slot as described in US 3,564,088

Preparation of Sheets of Nonwoven Flash-spun Plexifilamentary Fibrils by Collection, Consolidation, Bonding, Softening, and Articles Made from Sheets of Nonwoven Flash-spun Plexifilamentary Fibrils Sheets comprising plexifilamentary fibrils of polyolefin can be formed by any method known in the art, In some embodiments, the stream of fibrils discharged from each spin orifice is directed towards a deflector device which alternately directs the stream Of fibrils to the left and right onto a moving collecting device such that the fibrils accumulate in the form of a collected sheet of nonwoven flash-spun plexifilamentary fibrils, formed from fibrils oriented in an overlapping, multi-directional configuration. Deflection of the stream of fibrils may be achieved by any suitable means known in the art, including, but not limited to, those described in US 3,277,526 and US 3,387,326, US 3,169,899, US 3,497,918, US 3,456,156, US 3,593,074, US 3,851 ,023 and US 3,860,369, US 4,148,595, US 5,045,258, US 5,643,524, US 5,731,011, US 5,750,152 and WO92/20511, The stream of fibrils may also be laid dovm to form a collected sheet of nonwoven flash-spun : plexifilamentary fibrils without deflection as described in US 5,788,993 and US 8,114,325. The method of forming a collected sheet of nonwoven flash-spun plexifilamentary fibrils may forther utilize structures in the spin cell such as those described in US 5, 123, 983, US 5, 296, 172, and WO92/20511, In some embodiments, the streams of fibrils are discharged from spin orifices located on a rotating support, and the fibrils are collected on a collecting belt which surrounds the rotating arrangement circumferentially as described in US 7,118,698, US 7,621,731, US 7,786,034, and US 7,998,388

In some embodiments, the collected sheet of nonwoven flash-spun plexifilamentary fibrils formed by flash-spinning as described herein may be consolidated by applying a small amount of pressure to the sheet ^; to form a consolidated sheet of nonwoven flash-spun plexifilamentary fibrils In some embodiments, the sheet may be passed under a roller which applies pressure to the sheet to form a consolidated : sheet

In some embodiments, a consolidated sheet as described herein is subjected to thermal or mechanical bonding as known in the art to form a thermally or mechanically bonded sheet Bonding may also be achieved by impregnation of a consolidated sheet with a chemical bonding agent, either throughout the entire sheet, or at isolated points distributed over the sheet, or patern-wise. in some embodiments, the .bonded sheet is subjected to a mechanical softening process to obtain a softened sheet of nonwoven flash-spun plexifilamentary fibrils.

In some embodiments, an antistatic treatment is applied to the bonded or softened sheet. In some embodiments, the antistatic treatment is applied by applying a coating composition comprising an antistatic compound,

Further embodiments relate to a multilayer structure comprising at least one sheet of nonwoven flash-spun plexifilamentary fibrils as described herein, and at least one further sheet or a film. In some embodiments, the sheet of nonwoven flash-spun plexifilamentary fibrils as described herein is a collected sheet, a consolidated sheet, a bonded sheet, or a softened sheet.

The sheet of nonwoven flash-spun plexifilamentary fibrils as described herein has many uses and may be used in a variety of articles and applications, including, but not limited to, multilayer structures, garments (including, but not limited to, protective apparel), house wrap, roof lining, car covers, medical and non-medical packaging, filtration media, print media, tags and labels, and accessories. The uniform appearance and opaqueness of such sheet of nonwoven flash-spun plexifilamentary fibrils is particularly suitable for printing. EXAMPLES

A study has been performed for the phase behavior and flash spinning of polyethylene, polypropylene, and poly(4-methyl-1-pentene) for different compositions. The experimental procedure and results are provided below. These examples are given to illustrate exemplary embodiments of the invention and should not be interpreted as limiting in any way.

Materials Used

Dichloromethane (DCM), CAS No. of 75-09-2 has an atmospheric boiling point of

39.6 °C and a molecular weight of 84.93 g/mol. The dichloromethane used had a purity level above 99.5 percent by weight. Trans-1,2-dichloroethyiene (trans-1,2-DCE), CAS No. 156-60-5, has an atmospheric boiling point Of 48 °C and a molecular weight of 96.94 g/mol. The trans- 1,2-dichloroethylene used had a purity level above 98 percent by weight.

Cis-1 ,2-dichloroethylene (cis- 1 ,2-DCE), CAS No. 156-59-2, has an atmospheric boiling point of 60 °C and a molecular weight of 96.94 g/mol. The cis-1, 2-dichlOroethylene used had a purity level above 97 percent by weight

Trichloromethane (TCM), CAS No. 67-66-3, has an atmospheric boiling point of 61 °C and a molecular weight of 119.38 g/mol. The trichloromethane used had a purity level above 99 percent by weight.

N-pentane, CAS No. 109-66-0, has an atmospheric boiling point of 36 °C and a molecular weight of 72.15 g/mol. The n-pentane used had a purity level above 99 percent by weight.

1 -pentene, CAS No. 109-67-1, has an atmospheric boiling point of 30°C and a molecular weight of 70.13 g/mol . ^: The 1 -pentene used had a purity level above 98.5 percent by weight. 2-Methylbutane (isopentane), CAS No. 78-78-4, has an atmospheric boiling point of 30 ’C and a molecular Weight of 72.15 g/mol The 2-methylbutane used had a purity level above 97 percent by weight

N-hexane, CAS No. 110-54-3, has ah atmospheric boiling point of 69 °C and a molecular weight of 86.16 g/mol. The n-hexane used had a purity level above 95 percent by weight.

2-Methylpentane (2-MP), CAS No. 107-83-5, has an atmospheric boiling point of 60 °C and a molecular weight of 86,18 g/mol The 2-methylpentane used had a purity level above 99 %, 3-Methylpentane (3-MP), CAS No 96-14-0. has an atmospheric boiling point of 64 ^CC and a molecular weight of 86.18 g/mol. The 3-methylpentane used had a purity level above 99 %.

2.2-Dimethylbutane, CAS No. 75-83-2, has an atmospheric boiling point of 49 °C and a molecular weight of 86.18 g/mol . The 2,2-dimethylbutane used had ^; a purity level above 98 %.

2.3-Dimethylbutane, CAS No. 79-29-8, has an atmospheric boiling point of 58 °C and a molecular weight of 86.18 g/mol. The 2, 3-dimethylbutane used had a purity level above 98 %.

1.1.1.3.3-pentafluorobutane (HFC-365mfc), CAS No. 406-58-6, has an atmospheric: boiling point of 41.0 and a molecular weight of 148.04 g/mol. The 1,1, 1 ,3,3- pentafluorobutane used had a purity level above 99 5 percent by weight

Five different polyethylenes were used:

Polyethylene A was a polyethylene having a density of 0.955 g/cm³ (ISO 1183) and melt flow rates of 6.75 g/1 Omin (ISO 1133, 190 ’C/2.16 kg).

Polyethylene B was a polyethylene having a density of 0.960 g/cm³ (ISO 1183) and melt flow rates of 0.9 g/10min (ISO 1133, 190 ’C/2.16 kg).

Polyethylene C was a polyethylene having a density of 0.957 g/cm³ (ISO 1183) and a meltflow rate of 0.27 g/10min (IS0 1133, 190 *0/2.16 kg). Polyethylene D was a polyethylene having a density of 0.957 g/cm³ (ISO 1183) and a melt flow rate of 1.2 g/1 Omin (ASTM D1238, 190 ’C/2.16 kg).

Polyethylene E was a polyethylene havinga density of 0.951 g/cm³ (ISO 1183) and a melt flow rate 2.1 g/1 Omin (ISO 1133, 190 “C/21.6 kg).

The polypropylene (PR) used was an isotactic polypropylene a melt flow rate of 4.5 g/10 min (ISO 1133, 230 ’0/2.16 kg) and a melt peak temperature of 163 °C.

The poly(4-methyl-1 -pentene) (PMP) used has a melting peak of 233’0 and a melt flow rate of 5 g/10 min (ISO 1133, 260 ’0/2.16kg) and 23 g/10 min (ISO 1133, 260 °0/5kg). All polymers used were dried during a minimum of 8 hours in a vacuum oven at about 45-50 ®e before use. Spinning Equipment

All polymers were dried during a minimum of 8 hours in a vacuum oven at about 45- 50 °C before use.

Spinning Equipment The apparatus used consisted of two high pressure cylindrical chambers, each equipped with a piston which was adapted to apply pressure to the contents of the vessel. The cylinders had an inside diameter of 1.0 inch (25.4 mm) and each had an internal capacity of 50 cubic centimeters. The cylinders were connected to each other at one end through a 3/32 inch (2.3 mm) diameter channel and a mixing chamber containing a series of fine mesh screens was used as a static mixer. In the channel, a Type J thermocouple was in contact with the spin fluid to record the temperature. Mixing was accomplished by forcing the contents of the vessel back and forth between the two cylinders through the static mixer. A spinneret assembly with a quick-acting means for opening the orifice was attached to the channel through a tee. The spinneret assembly consisted of a lead hole with a diameter of 0 25 inch (6.3 mm) and a length of about 2.0 inch (50.8 mm), and a spinneret orifice with a diameter of

0.020 inch (0.508 mm) and a length of 0.020 inch (0.508 mm). A pressure transmitter calibrated at the spin temperature was mounted in the lead hole to measure the pressure of the spin fluid. The pistons were driven by a high-pressure hydraulic system. _;

In operation, the apparatus was charged with polymer pellets and spin agent and a pressure of at least 50 bar was applied to the pistons to compress the charge and avoid the spin fluid from boiling during subsequent heating. The contents were then heated to mixing temperature and held at that temperature for about 30 to 45 minutes during which time a differential pressure was alternatively established between the two cylinders to repeatedly force the contents through the mixing channel from one cylinder to the other to provide mixing and effective formation of a spin fluid. The spin fluid temperature was then increased to the final spin temperature and held there for about 10 to 20 -minutes to equilibrate. The pressure of the spin fluid was kept above the cloud point pressure during mixing and during the increase in temperature from the mixing temperature to the spin temperature. Mixing was continued throughout this period. Atthe end Of the mixing cycle, the accumulator was settothe pressure desired for spinnihg. Next, the valve between the accumulator and the twin piston assembly was opened to reduce the pressure of the spin fluid to the desired spin pressure, and about two to five seconds later, the spinneret orifice was opened to release the spin fluid into conditions Of atmospheric pressure. The delay of about two to five seconds corresponds to the residence time in the letdown chamber in a continuous spinning process. The resultant stream of flash-spun fibrils was collected in a stainless-steel open mesh screen basket. During spinning, the spin pressure was recorded just upstream of the spinneret.

For cloud point pressure determination, the spinneret assembly was replaced with a view cell assembly containing a 1/2 inch (12.3 mm) diameter high-pressure sight glass, through which the contents of the cell could be viewed as they flow through the channel. The window was I it by means of a fiber optic light guide, while the view through the sight glass was displayed using a digital camera. In the cell, a Type J thermocouple was located about 5 mm behind the high-pressure sight glass. The Type J thermocouple and a pressure measuring device located in close proximity to the window measured the pressure and temperature inside the view cell behind the sight glass and the pressure and temperature were continuously monitored by a computer. When, after a period of mixing, a clear, homogeneous spin fluid was established, the temperature was held constant and the differential pressure applied to : the pistons was equalized so that the pistons stopped moving. Then, the pressure applied to the spin fluid In the view celt was gradually decreased until phase separation -was -observed through the sight glass, as the initially dear, homogeneous spin fluid became cloudy in appearance. The temperature arid pressure were recorded when the thermocouple became no longer visible. This pressure was the phase separation pressure or cloud point pressure for that spin fluid at that temperature The pressure Was then -increased until the spin fluid returned to its transparent state, i.e,. until the insoluble phase redissolved, and in this way. two or three repeat cloud point -measurements could be made at an approximately constant temperature. Once this data was recorded, mixing was resumed while the spin fluid was iieated to the next temperature at which the cloud point pressure was to be measured.

_: Results

Example 1 : Cloud point pressure study of polyethylene and polypropylene Figure 1 shows the cloud point pressure curve of a spin fluid comprising 22 wt% polyethylene A and a spin agent of dichloromethane and n-pentane in a 49.1 :50.9 ratio by weight. This spin fluid comprising 22 wt% polyethylene shows a cloud point pressure curve suitable tor flash spinning.

Figure 1 further shows the cloud point pressure curve of a spinfluid comprising 10 wt% polypropylene and a spin agent of dichloromethane and n-pentane in a 49.1:50,9 ratio by weight This spin fluid comprising 10 wt% polypropylene shows a cloud point pressure curve suitable for flash spinning.

Example 2: Cloud point pressure study of polyethylene and polypropylene Figure 2 shows the cloud point pressure curve of a spin fluid comprising 18 wt% polyethylene E and a spin agent of dichloromethane and 2-methylbutane in a 27:73 ratio by weight. This spin fluid comprising 18 wt% polyethylene shows a cloud point pressure curve suitable for flash spinning.

^; Figure 2 further shows the cloud point pressure curve of a spin fluid comprising 20 wt% polyethylene B and a spin agent of dichloromethane and 2-methylbutane in a 35:65 ratio by weight This spin fluid comprising 20 wt% polyethylene shows a cloud point pressure curve suitable for flash spinning.

Figure 2 further shows the cloud point pressure curve of a spin fluid comprising 14 wt% polypropylene and a spin agent of dichloromethane and 2-methylbutane in a 27:73 ratio by weight. This spin fluid comprising 14 wt°/o polypropylene shows a cloud point pressure curve suitable for flash spinning.

Example 3: Cloud point pressure study of polyethylene ^:

Figure 3 shows the cloud point pressure curve of a spin fluid comprising 16 wt% polyethylene D and a spin agent of trans- 1 ,2-dichloroethylene and 1 -pentene in a 40:60 ratio by weight. This spin fluid comprising 16 wt% polyethylene shows a cloud point pressure curve suitable for flash spinning.

Example 4: Cloud point pressure study of polyethylene Figure 4 shows the cloud point pressure curve of a spin fluid comprising 18 wt% polyethylene B and a spin agent of trichloromethane and n-hexane in a 46:54 ratio by weight. This spin fluid comprising 18 wt°/o polyethylene shows a cloud point pressure curve suitable for flash spinning. Example 5: Flash spinning experiments CE-1 to CE-5 ^:and:E< to:£-7

Flash spinning was performed on the equipment described above. The spin agent composition, polymer type, polymer concentration and approximate spin temperature and spin pressure are summarized in below tables. Table A: Summary of the flash spinning (comparative examples/polyethylene)

• 1H, I H 1 H,3H 3H-pentafluotobutane (HFC-365mfci

** assuming a GWP of 11.2 for the dichloromethane and a GWP of 914 for HFC-365mfc.

Table B: Summary of the flash spinning (examples/polyethylene) * assuming a GWP of 11 2 for the dichloromethane and a GWP of about zero for the n-pentane

The spin agents used in the examples exhibit a desirably low G WP value of less than

10. This makes these compositions suitable as replacements for spin agents disclosed in the prior art. In addition, the above examples illustrate that the compositions can be used as a spin agent for the flash spinning process of polyethylene for different polymer concentrations, spin temperatures, and spin pressures. Comparison of the comparative examples and the examples show an improved flash spinning behavior. The web fibrillation is obtained over a larger domain of spin temperatures and polymer concentrations. The BET surface area is found to be generally higher for the spin agent based on dichloromethane and the hydrocarbon compared to the spin agent of dichloromethane and 1 ,1,1 ,3,3-pentafluorobutane. In addition, as illustrated in Figure 5 for the comparative examples using spin agents of dichloromethaneand 1,1,1, 3,3-pentafluorobutane, the BET surface area increases with increasing polymer concentration, whereas the opposite trend is seen for the examples using spin agents of dichloromethane and n-pentane. Further, as illustrated in Figure 6 for the comparative examples using spin agents of dichloromethane and 1 ,1 ,1 , 3,3-pentafluorobutane the BET surface area increases with increasing temperature, whereas the opposite trend is seen for the examples using spin agents of dichloromethane and n-pentane. Thus, when using the spin agents as described herein, a high BET surface area, i.e., a high reflectivity, as well as fine flbriliated webs can be generated at lower spin temperatures and at higher polymer concentrations compared to the comparative examples. The possibility of using lower spin temperatures and/or the higher polymer concentrations has the advantage that less energy is needed for the spin process thereby reducing the carbon footprint per un it of fabricated product.

Example 6: Flash spinning experiments E-8 to E-23

Flash spinning was performed on the equipment described above. The spin agent composition, polymertype, polymer concentration and approximate spin temperature and spin pressure are summarized in below tables.

Table C: Summary of the flash spinning (examples/polyethylene)

’ assuming a GWP of 11 2 for the dichloromethane (CCM) and a GWP of about zero for the n-pentane. the 2-methylbutane and the n-hexane blend of PE A and PMP in a 80*20 weight ratio Table D: Summary of the flash spinning (examples/polyethylene)

Table E: Summary of the flash spinning (examples/polypropylene)

The spin agents used in the examples exhibit a desirably low GWP value of less than 10. This makes these compositions suitable as replacements for spin agents disclosed in the prior art. In addition, the above examples illustrate that the compositions can be used as a spin agent for the flash spinning process of different polyolefins for different polymer concentrations, spin temperatures, and spin pressures. In particular, when using the spin agents as described herein it is possible to achieve a fine, well-fibrillated web at low spin temperatures and at high polymer concentrations, thereby reducing the carbon footprint per unit of fabricated product

OTHER EMBODIMENTS 1. In some embodiments, the present application provides a spin fluid for flash spinning comprising (a) from about 9 to about 25 weight percent of a polyolefin, based on the total amount of the spin fluid, and (b) a spin agent, wherein the spin agent comprises a composition comprising at least one chlorinated solvent, selected from dichloromethane, lrans-1,2- dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and at least one linear or bfanched hydrocarbon with 5 to 6 carbon atoms.

2. The spin fluid of embodiment 1 comprising about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid.

3. The spin fluid of embodiment 1 or 2 comprising from about 75 to about 91 weight percent of the spin agent, or from about 75 to about 90 weight percent of the spin agent, or from about 80 to about 88 weight percent of the spin agent, or from about 84 to about 91 weight percent of the spin agent, or from about 39 to about 91 weight percent of the spin agent or from about 75 to about 85 weight percent of the spin agent, or from about 75 to about 82 weight percent of the spin agent, each based on the total amount of the spin fluid

4. The spin fluid of any of embodiments 1 to 3, wherein the polyolefins are selected from the group consisting of polyethylene, polypropylene, polybutene-1 , poly(4-methyl-1-pentene), and blends/mixtures thereof.

5. The spin fluid of any of embodiments 1 to 4, wherein the polyolefins are selected from the group consisting of polyethylene (PE), polypropylene (PP),and blends/mixtures thereof. 6. The spin fluid of any of embodiments 4 to 5, wherein the polyethylene is a high-density polyethylene (HOPE), a blend of a high-density polyethylene (H DP E) with a low-density polyethylene (LDPE), or a blend of a high-density polyethylene (HDPE) with a linear low- density polyethylene (LL.DPE),

7. The spin fluid of any of embodiments 1 to 6, wherein the at least one linear or branched hydrocarbon with 5 to 6 carbon atoms is selected from the group consisting of n-pentane, 1- pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane,

2,3-dimethylbutane, 2-methyl-2-butene, 2-methyM-butene, and 1-hexene.

8. The spin fluid of any of embodiments 1 to 7, wherein the spin agent comprises, consists essentially of, or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting < of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

9. The spin fluid of any of embodiments 1 to 7, wherein the spin agent comprises, consists essentially of, or consists of cis-1,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group insisting of n-pentane, 1- pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane,

2, 3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1 -hexene.

10. The spin fluid of any of embodiments 1 to 7, Wherein the spin agent comprises, consists essentially of, or consists of trans- 1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pehtane, 1 - pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane,

2, 3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

11. The spin fluid of any of embodiments 1 to 7, wherein the spin agent comprises, consists essentially of, or consists of trans-1 ,2-dichloroethylene and cis-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2, 3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene.

12. The spin fluid of any of embodiments 1 to 7, wherein the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2- methylbutahe, n-hexane, 2-methylpehtane, 3-methylpentane, 2, 2-dimethylbutahe, 2,3- dimethylbutane, 2-methyl-2»butene, 2-methyl-1 -butene, and 1-hexene. 13. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis- 1,2-dichloroethylene, and trichloromethane, and from about 99 to about 40 weight percent or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 6 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, <3* methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene. 14. The spin fluid of any one of embodiments 1 to 13, wherein the spin agent com prises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis- 1 ,2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene. 15 The spin fluid of any one of embodiments 1 to 13. wherein the spin agent comprises, consists essentially of. or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent selected from dichloromethane, trans-1.2-dichloroethylene. cis-1.2-dichloroethylene. and trichloromethane. and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methy I- 1- butene, and 1-hexene, 16. The spin fluid of any one of embodiments 1 to 13, wherein the spin agent comprises, consists essentially of, or consists of, or consists of from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms Selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexanP, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene.

17. The spin fluid of any one of embodiments 1 to 13, wherein the spin agent comprises, consists essentially of, or consists of (i) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or (ii) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of 2-methylbutane .

18. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists oFfrom about 1 to about 70 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene. ^;

19. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 ^; weight percent of at least one chlorinated solvent, Selected from dichloromethane. trans-1.2-dichloroethylene. cis-1 ,2-dichloroethylene. and tnchloromethane. and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at i least one linear _: or branched hydrocarbon With 5 carbon atoms selected fro m t he group consisting of n-pentane. 1-pentene. 2-methylbutane. 2-methyl-2-butene, and 2-methyl-1- butene.

20. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene.

21. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane, or from about 20 to about 48 weight percent of dichloromethane and from about 80 to about 52 weight percept of 2-methylbutane. 22. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of , or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-l,2*dichloroethylene, cis«1,2-dichloroethylehe, and trichloromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene. 2-methyl-1- butene, and 1 -hexene. 23. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane. trans-1.2-dichloroethylene. cis-1.2- dichloroethylene, and tnchloromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane. 1 -pentene. 2-methylbutane. n-hexane, 2-methylpentane, 3- methylpentane. 2.2-dimethylbutane. 2.3-dimethyibutane. 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene. ^;

24. The spin fluid of any one of embodiments 1 to 12, wherein the spin, agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about

10 to about 45 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1* butene. 25. The spin fluid of any one of embodiments t to 12, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl*1 -butene. 26. The spin fluid of any one of embodiments 1 to 12, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichioromethane, trans- 1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 85 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene.

27, The spin fluid of any one of embodiments I to 26, wherein the spin agent comprises or consists essentially of (1) an azeotropic or azeotropeTike composition comprising dichioromethane and n-pentane, or (2) an azeotropic or azeotrope-like composition comprising dichioromethane and 3-methylbutane, or (3) an azeotrope-like Composition comprising trichloromethane and n-hexane.

28. The spin fluid of embodiment 27, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of , or consist of from about f to about 70 weight percent dichioromethane and from about 30 to about 99 weight percent n-pentane or from about 31 to about 70 weight percent dichioromethane and from about 69 to about 30 weight percent n-pentane. 29. The spin fluid of embodiment 28, wherein the azeotropic dr azeotrope-like composition boils at a temperature of about -20 ’C to about 100 'C and at a boiling pressure of about 10 kPa to about 703 kPa.

30. The spin fluid of embodiment 27 or 28, wherein the azeotropic or azeotrope-like_: compositions comprise, consist essentially of, or consist of from about 31 to about 63 weight percent dichioromethane and from about 69 to about 37 weight percent n-pentane. 31. The spin fluid of embodiment 30, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 °C and at a boiling pressure of about 132 kPa to about 139 kPa.

32. The spin fluid of embodiment 27 or 28, wherein the azeotropic compositions comprise, consist essentially of, or consist of from about 43 to about 58 weight percent dichloromethane and from about 57 to about 42 weight percent n-pentane 70 weight percent dichloromethane and from about 69 to about 30 weight percent n-pentane.

33. The spin _: fluid of embodiment 32^ wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 11 kPa to about 703 kPa.

34. The spin fluid of embodiment 32 or 33, wherein the azeotropic compositions comprise, consists essentially of or consists of about 50.9 weight percent dichloromethane and about

49.1 weight percent n-^ntane. \

35. The spin fluid of embodiment 34, wherein the azeotropic composition boils at a temperature of about 25 *C and at a boiling pressure of pressure of about 82 kPa

36. The spin fluid of embodiment 32 or 33, wherein the azeotropic compositions comprise, consists essentially of or consists of about 51.0 weight percent dichloromethane and about 49.0 weight percent n-pentane.

37. The spin fluid of embodiment 36, wherein the azeotropic composition boils at a temperature of about 40 C and at a boiling pressure of pressure of about 138.9 kPa

38. The spin fluid of embodiment 32 or 33. wherein the azeotropic compositions comprise, consists essentially of or consists of about 49.8 weight percent dichloromethane and about

50.2 weight percent n-pentane.

39. The spin fluid of embodiment 38, wherein the azeotropic composition boils at a temperature of about 30.8 °C and at a boiling pressure of pressure of about 101 .3 kPa.

40. The spin fluid of embodiment 27, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent 2-methylbutane, or from about 24 to about 70 weight percent dichloromethane and from about 76 to about 30 weight percent 2-methylbutane.

41. The spin fluid of embodiment 40, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 "C to about 100 ’C and at a boiling pressure of about 13 kPa to about 775 kPa

42. The spin fluid of embodiment 40 or 41, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 15 to about 56 weight percent dichloromethane and from about 85 to about 44 weight percent 2-methylbutane or from about 25 to about 51 weight percent dichloromethane and from about 75 to about 49 weight percent 2-methylbutane.

43. The spin fluid of embodiment 42, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 ’G and at a boiling pressure of about 157 kPa to about 163 kPa.

44. The spin fluid of embodiment 27 or 40, wherein the azeotropic compositions comprise, consist essentially of, or consist of from about 26 to about 42 weight percent dichloromethane and from about 74 to about 58 weight percent 2-methylbutane.

45. The spin fluid of embodiment 44, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 14 kPa to about 775 kPa. ^{: :}

46. The spin fluid of embodiment 44 or 45, wherein the azeotropic compositions comprise, consists essentially of or consists of about 35.0 weight percent dichloromethane and about 65.0 weight percent 2-methylbutane.

47. The .spin fluid of embodiment 46, wherein the azeotropic composition boils at a temperature of about 40 ' C and at a boiling pressure of pressure of about 162 6 kPa.

48. The spin fluid of embodiment 44 or 45, wherein the azeotropic compositions comprise, consists essentially of or consists of about 33.1 weight percent dichloromethane and about 66.9 weight percent 2-methylbutane. 49. The spin fluid of embodiment 48, wherein the azeotropic composition boils at a temperature of about 25 7 C and at a boiling pressure of pressure of about 101.3 kPa

50. The spin fluid of embodiment 27, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 60 weight percent trichloromethane and from about 40 to about 99 weight percent n-hexane, or from about 46 to about 60 weight percent trichloromethane and from about 54 to about 40 weight percent n-hexane. 51. The spin fluid of embodiment 50, wherein the azeotropic or azeotrope-like composition boils _: at a temperature of about -20 °C to about 100 °C and at a ^: boiling pressure of about 20 kPa to about 315 kPa.

52; The spin fluid of embodiment 50 or 51, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially < or consist of from about 46 to about 60 weight percent trichloromethane and from about 54 to about 40 weight percent n-hexane.

53. The spin fluid of embodiment 52, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 *G and at a boiling pressure of about 45 to 48 kPa .

54. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 1 to about 60 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 40 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane. 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene. 55. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists Of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichIoroethylene, and trichloromethane,

_: and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methyipentane, 2,2-dimethylbutane, 2j3-dimethylbutane, 2»methyl-2*butene, 2-methyl*1- butene, and 1 -hexene.

56. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 Weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichl0roethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2.3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene.

57 The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of (1 ) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or (2) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of 2-methylbutane.

58. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, Wherein the spin agent comprises, consists essentially of. or consists of from about 1 to about 70 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-diGhloroethylene, and trichloromethahe, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting Of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene, ^;

59. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichioroethylene, and frichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene. 60. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 1 1 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid , and a spin , agent, wherein the spin agent com prises, consists essentially of, or consists offrom about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethylene, cis-1, 2-diGhloroethylehe, and trichioromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1* butene. 61 The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 1 1 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid and a spin agent, wherein the spin agent comprises consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane,

62. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 56 weight percent or from about 25 to about 51 weight percent of dichloromethane and from about 85 to about 44 weight percent or from about 75 to about 49 weight percent of 2-methylbutane.

63. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1.2-dichloroethylene. and trichloromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

64. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 . or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 80 to about 70 weight percent of at least One linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentahe, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene.

65. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent Of a polyolefin, selected from a polypropyiene, a polybutene-1, or a poly(4-methyl-l -pentene), each Pased on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or insists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane.

66. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-l -pentene), each based on the total amount of the spin fluid, and a spin agent , wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 45 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or ^; branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane.

1 -pentene, 2-methylbutane, 2-methyi-2-butene, and 2-methyl-l -butene.

67. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, Or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-l,2- dichloroethylene, and trichloromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methyl butane, 2-methyi-2-butene, and 2-methyl-1-butene.

68. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1, ora poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cls-1 ,2- dichloroethylene, and trichloromethane, and from about 85 to about 70 weight, percent of at ^: least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene.

69. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a poiybutene-1 , or a poly(4-methyl-l -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially Of, or consists of from about 31 to about 63 Weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane.

70. The spin fluid of any of embodiments 1 to 53 comprising about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or aboutTO to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene- 1 . or a poly(4-methyl-1 -pentene). each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 56 weight percent or from about 25 to about 51 Weight percent of dichloromethane and from about 85 to about 44 weight percent or from about 75 to about 51 weight percent of 2-methylbutane.

71 . In some embodiments, the present application provides a process for the preparation of plexifilamentary fibrils of polyolefin which comprises the steps of: (i) generating a spin fluid comprising

(a) from about 9 to about 25 weight percent of a polyolefin, based on the total

; amount of the spin fluid, and (b) a spin agent, and

(ii) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the polymer, wherein the spin agent comprises a composition comprising at least one chlorinated solvent selected from dichloromethane, trans- trichloroethylene, as-1,2-dichloroethylene, and trichloromethane, and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

72. The process of embodiment 71, wherein the spin fluid comprises about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about ; 25 weight percent of a polyethylene, each based on ^: the total amount of the spin fluid .

73. The process of embodiment 71 or 72, wherein the spin fluid comprises from about 75 to about 91 weight percent of the spin agent, or from about 75 to about 90 weight percent of the spin agent, or from about 80 to about 88 weight percent of the spin agent, or from about 84 to about 91 weight percent of the spin agent, or from about 89 to about 91 weight percent of the spin agent, or from about 75 to about 85 weight percent of the spin agent, or from about 75 to about 82 weight percent of the spin agent, each based on the total amount of the spin fluid.

74; The process of any of embodiments 71 to 73, wherein the polyolefins are selected from the group consisting of polyethylene, polypropylene, polybutene-1 , poly(4-methyl-1 -pentene), and biends/mixtures thereof.

75. Theprocess of any of embodiments 71 to 74, wherein the polyolefins are selected from, the group consisting of polyethylene (PE), polypropylene (PP). and biends/mixtures thereof

76. . The process of any of embodiments 74 to 75, wherein the polyethylene is a . high- density polyethylene (HDPE), a blend of a high-density polyethylene (HDPE) with a low- density polyethylene (LDPE), or a blend of a high-density polyethylene (HDPE) with a linear ^; low-density polyethylene (ULDPE).

77. The process of any of embodiments 71 to 76, wherein the at least one linear or branched hydrocarbon with 5 to 6 carbon atoms is selected from the group consisting of n- pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2*methyl-l-butene, and 1-hexene, 78. The process of any of embodiments 71 to 77, wherein the spin agent comprises, consists essentially of. or consists of dichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 - pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1-butene, and 1-hexene,

79. The process of any of embodiments 71 to 77, wherein the spin agent comprises, consists essentially of, or consists of cis-1,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n- pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2, 3-dimethy ibutane, 2-methyl-2-butene, 2-methyl- 1 -butene, and 1-hexene,

80. The process of any of embodiments 71 to 77, wherein the spin agent comprises,consists essentially of, or consists of trans-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with S to 6 carbon atoms selected from the group consisting of n- pentane, 1-penterie, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2- dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene. 81 The process of any of embodiments 71 to 77, wherein the spin agent comprises, consists essentially of, or consists of trans-1 ,2-dichloroethylene and cis-1 ,2-dichloroethylene and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane 1-pentene, 2-methylbutane, n-hexane. 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl- 1- butene, arid 1-hexene.

82. The process of any of embodiments 71 to 77, wherein the spin agent comprises, consists essentially of, or consists of trichloromethane and at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1- pentene^ 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

83. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichlofomethane, trans-1,2-dichloroethylene, cis-1, 2-dichloroethytene, and trichloromethane, and from about 99 to about 40 weight percent or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2-rnethylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butehe, 2-methyl-1- butene, and 1 -hexene.

84. The process of any one of embodiments 71 to 83, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1,2-dichlbroethylene, cis-1,2-dichloroethyiene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene.

85. The process of any one of embodiments 71 to 83, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichlOroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 50 to about 40 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene.

86. The process of any one of embodiments 71 to 83 wherein the spin agent comprises, consists essentially of, or consists of, or consists of from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1.2-dichloroethylene. cis-1 ,2-dichloroethylene, and trichloromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 catoon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene, 87. The process of any one of embodiments 71 to 83, wherein the spin agent comprises, consists essentially of, or consists of (i) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or fri) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of 2-methyibutane

88. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 70 weight percent, or from about

20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-l- butene.

89. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichioromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 Carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene.

90. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethyiene. cis-1 ,2-dichloroethylene and trichioromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon With 5- carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene.

91 . The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane, or from about 20 to about 48 weight percent of dichloromethane and from about 80 to about 52 weight percent of 2-methylbutane. 92. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1.2-dichloroethylene, and trichloromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene.

93. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2- dichloroethylene, and trichloromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene. 94. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 45 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1.2-dichloroethylene. cis-1 ,2-dichloroethylene. and tnchloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene. 2-methylbutane. 2-methyl-2-butene. and 2-methyl-1- butene.

95. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloramethane, trans-1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about S3 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene. 96. The process of any one of embodiments 71 to 82, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2- dichloroethylene, and trichloromethane, and from about 85 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutarie, 2-methyl-2-butene, and 2-methyM- butene.

97. The process of any one of embodiments 71 to 96, wherein the spin agent comprises or consists essentially of (1) an azeotropic or azeotrope-like composition comprising dichloromethane and n-pentane, or (2) an azeotropic or azeotrope-like composition comprising dichloromethane and 3-methylbutane, or (3) an azeotrope-like composition comprising trichloromethane and n-hexane. 98 The process of embodiment 97, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent n-pentane, or from about 31 - to about 70 weight percent dichloromethane and ffom about 69 to about 30 weight percent n- pentane.

99. The process of embodiment 98, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 C to about 100 C and at a boiling pressure of about 10 kPa to about 703 kPa. 100 The process of embodiment 97 or 98. wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 31 to about 63 weight percent dichloromethane and from about 69 to about 37 weight percent n-pentane.

101. The process of embodiment 100, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 °C and at a boiling pressure of about 132 kPa to about

139 kPa.

102. The process of embodiment 97 or 98, wherein the azeotropic compositions comprise, consist essentially of, or consist of from about 43 to about 58 weight percent dichloromethane and from about 57 to about 42 weight percent n-pentane 70 weight percent dichloromethane and from about 69 to about 30 weight percent h-pentane. 103. The process of embodiment 102, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 11 kPa to about 703 kPa. 104. The process of embodiment 102 or 103, wherein the azeotropic compositions comprise, consists essentially of or consists of about 50.9 weight percent dichloromethane and about 49.1 weight percent n-pentane.

105. The process of embodiment 104, wherein the azeotropic composition boils at a temperature of about 25 "C and at a boiling pressure of pressure of about 82 kPa.

106. The process of embodiment 102 or 103, wherein the azeotropic compositions comprise, consists essentially of or consists of about 51.0 weight percent dichloromethane and about 49.0 weight percent n-pentane.

107. The process of embodiment 106, wherein the azeotropic composition boils at a temperature of about 40 °C and at a boiling pressure of pressure of about 138.9 kPa.

108. The process of embodiment 102 or 103, wherein the azeotropic compositions comprise, consists essentially of or consists of about 49.8 weight percent dichloromethane and about 50.2 weight percent n-pentane.

109. The process of embodiment 108. wherein the azeotropic composition boils at a temperature of about 30.8 C and at a boiling pressure of pressure of about 101.3 kPa.

1 10 The process of embodiment 97, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of. or consist of from about 1 to about 70 weight percent dichloromethane and from about 30 to about 99 weight percent 2-methylbutane, or from about 24 to about 70 weight percent dichloromethane and from about 76 to about 30 weight percent 2-methylbutane,

1 11. The process of embodiment 110. wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 13 kPa to about 775 kPa.

112. The process of embodiment 1 10 or 111, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 15 to about 56 weight percent dichloromethane and from about 85 to about 44 weight percent 2-methyibutane or from about 25 to about 51 weight percent dichloromethane and from about 75 to about 49 weight percent 2-methylbutahe. 113. The process of embodiment 112, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 “C and at a boiling pressure of about 157 kPa to about 163 kPa.

114. The process of embodiment 97 or 110, wherein the azeotropic compositions comprise, consist essentially of, or consist of from about 26 to about 42 weight percent dichloromethane and from about 74 to about 58 weight percent 2-methylbutane.

115. The process of embodiment 114, wherein the azeotropic composition boils at a temperature of about -20 °C to about 100 °C and at a boiling pressure of about 14 kPa to about 775 kPa.

116. The process of embodiment 114 or 115, wherein the azeotropic compositions comprise, consists essentially of or consists of about 35.0 weight percent dichloromethane and about 65.0 weight percent 2-methylbutane.

117. The process of embodiment 116, wherein the azeotropic composition boils at a temperature of about 40 "C and at a boiling pressure of pressure of about 162.6 kPa

118. The process of embodiment 114 or 115, wherein the azeotropic compositions comprise, consists essentially of or consists of about 33.1 weight percent dichloromethane and about 66 9 weight percent 2-methylbutane

119. The process of embodiment 118, wherein the azeotropic composition boils at a temperature of about 25.7 °C and ata boiling pressure of pressure of about 101.3 kPa. :

120. The process of embodiment 97, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 1 to about 60 weight percent trichloromethane and from about 40 to about 99 weight percent n-hexane, or from about 46 to about 60 weight percent trichloromethane and from about 54 to about 40 weight percent n- hexane; 121. The process of embodiment 120, wherein the azeotropic or azeotrope-like composition boils at a temperature of about -20 °C to about 100 °G and at a boiling pressure of about 20 kPa to about 315 kPa

122. The process of embodiment 120 or 121, wherein the azeotropic or azeotrope-like compositions comprise, consist essentially of, or consist of from about 46 to about 60 weight percent trichloromethane and from about 54 to about 40 Weight percent n-hexane.

123. The process of embodiment 122, wherein the azeotropic or azeotrope-like composition boils at a temperature of about 40 °C and at a boiling pressure of about 45 to 48 kPa.

124. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 60 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichtoroethylene, and trichloromethane, and from about 99 to about 40 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 6 to 6 carbon atoms selected from the group consisting of n-pentane. 1 -pentene. 2-methylbutane. n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-l-butene, and 1-hexene.

125 The process of any of embodiments 71 to 123. wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherei n the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1, 2-dichloroethy!ene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group Consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, _:2-methyl-1 -butene, and 1 -hexene.

126. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 60 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1,2-dichloroethylene, cis-l ,2-dichloroethylene, and trichloromethane, and from about 50 to about weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, n-hexane, 2- methylperitane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2- butene, 2-methyl-1 -butene, and 1 -hexene.

127. The process of any of embodiments 71 to 123, wherein the spin fluid; comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about I T weight percent, or about 15 to about 25 Weight percent, or about 18 to about 25 weight percent of ^: a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of (1 ) from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or (2) from about 30 to about 60 wtoight percent of dichloromethane and from about 70 to about 40 weight percent of 2-methylbutane.

128. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, tor about 10 to about 25 weight percent, or about 12 to about 20 Weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 70 weight percent, or from about 20 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 30 weight percent, or from about 80 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from, the group consisting of n-pentane, _: 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene.

129. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 55 weight percent, or from about 40 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-diohloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent, or from about 60 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1 -butene.

130. The process of any of embodiments ?! to 123, wherein the spin fluid comprises about 9 to about 25 weight percent , or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about T1 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 50 to about 70 weight percent, or from about 5 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1,2-dichloroethylene. cis-l ,2-dichloroethylene. and trichloromethane, and from about 50 to about 30 weight percent, or from about 95 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyI-1 -butene. 131, The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane. 132. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 12 to about 20 weight percent, or about 9 to about 16 weight percent, or about 9 to about 11 weight percent, or about 15 to about 25 weight percent, or about 18 to about 25 weight percent of a polyethylene, each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 56 weight percent or from about 25 to about 51 weight percent of dichloromethane and from about 85 to about 44 weight percent or from about 75 to about 49 weight percent of 2-methylbutane. 133. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a .polypropylene, a polybutene-1 , or a poly(4-methyl-l-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 40 weight percent, or from about 10 to about 40 weight percent of at least one chlorinated Solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 99 to about 60 weight percent, or from about 90 to about 60 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1-hexene.

134. The process of any of embodiments 71 to 123, Wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight oercent. or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 20 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 80 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3- methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1- butene, and 1 -hexene. 135, The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene- 1 , or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 30 to about 60 weight percent of dichloromethane and from about 70 to about 40 weight percent of n-pentane or of 2-methylbutane, 136. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 1 to about 45 weight percent, or from about 10 to about 45 Weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1,2-dichloroethylene, and trichloromethane, and from about 99 to about 55 weight percent, or from about 90 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-i- butene.

137. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about

9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight oercent or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl- 1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 10 to about 50 weight percent, or from about 20 to about 50 weight percent, or from about 30 to about 50 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis- 1 ,2-dichloroethylene, and trichloromethane, and from about 90 to about 50 weight percent, or from about 80 to about 50 weight percent, or from about 70 to about 50 weight percent of at least one linear or branched hydrocarbon wth 5 carbon atoms selected from the group consisting of n-pentane, 1-pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-1- butene. 138. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight oercent. or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene- 1 , or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of, or consists of from about 15 to about 30 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1 ,2-dichloroethylene, Gis-1,2-dichloroethylene, and trichloromethane, and from about 85 to about 70 weight percent of at least one linear or branched hydrocarbon with 5 carbon atoms selected from the group consisting of n-pentane, 1 -pentene, 2-methylbutane, 2-methyl-2-butene, and 2-methyl-l- butene.

139. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about 10 to about 15 weight percent, or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1 , or a poly(4-methyl-1-pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin ragent comprises, consists essentially of, or consists of from about 31 to about 63 weight percent of dichloromethane and from about 69 to about 37 weight percent of n-pentane; ;

140. The process of any of embodiments 71 to 123, wherein the spin fluid comprises about 9 to about 25 weight percent, or about 10 to about 25 weight percent, or about 10 to about 20 weight percent, or about W to about 15 weight oercent. or about 15 to about 20 weight percent of a polyolefin, selected from a polypropylene, a polybutene-1. or a poly(4-methyl-1 -pentene), each based on the total amount of the spin fluid, and a spin agent, wherein the spin agent comprises, consists essentially of. or consists of from about 15 to about 56 weight percent or from about 25 to about 51 weight percent of dichlordmethane and from about 85 to about 44 weight percent or f rom about 75 to about 51 weight percent of 2-methylbutane. 141 . In some embodiments, the present application provides a use of the spin fluid of any of embodiments 1 to 70 for preparing plexifilamentary fibrils of polyolefin by flash spinning.

142. The plexifilamentary fibrils of polyolefin obtainable or obtained by the process of any one of embodiments 71 to 140.

143. The plexifilamentary fibrils of polyolefin of embodiment 142 having a BET surface area of about 5 to about 60 m^g, or having a BET surface area of from; about 10 to about 60 m^g, or having a BET surface area of from about 15 to about 60 m²/g, or having a BET surface area of from about 20 to about 60 m²/g, or having a BET surface area of from about 25 to about 60 m²/g, or having a BET surface area of from about 30 to about 60 m²/g, or having a BET surface area of from about 45 to about 60 rrr'/g.

144. The plexifilamentary fibrils of polyolefin of embodiment 142 having a BET surface area of about 13 to about 40 m^z/g, or having a BET surface area of from about 13 to about 30 m²/g, or having a BET surface area of from about 13 to about 20 m²/g,

145. A sheet of nonwoven flash-spun plexifilamentary fibrils comprising plexifilamentary fibrils of polyolefin of embodiment 142, 143, or 144.

146. The sheet of embodiment 146, wherein the sheet is a collected sheet, a consolidated sheet, a bonded sheet, or a softened sheet.

147. A bonded sheet obtainable by thermally or mechanically bonding the consolidated sheet of embodiment 146.

148. A softened sheet obtainable by softening toe consolidated sheet of embodiment 146 or by softening the bonded sheet of embodiment 147.

149. An article comprising plexifilamentary fibrils of polyolefin of embodiment 142, 143, or 144 and/or a sheet of any one of embodiments 145 to 148.

150. The article of embodiment 149 winch is selected from garment, protective apparel, packaging material, house wrap, roof lining, car covers, medical and non-medical packaging, filtration media, print media, tags and labels, and accessories.

While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the present invention. Thus, it should be appreciated that, while toe invention has been described with reference to toe above exemplary embodiments, other embodiments are within the scope of the claims. Moreover, it should be understood that the exemplary embodiments described herein may be combined to form other embodiments. After reading the above description, it will be apparent to one skilled in the relevant art(s) how to implement the invention in alternative embodiments. Thus, the present invention should not be limited by any of the above-described exemplary embodiments.

Claims

1. A spin fluid for flash spinning comprising

(a) from about 9 to about 25 weight percent Of a polyolefin, based on the total amount of the spin fluid, and

(b) a spin agent, wherein the spin agent comprises a composition comprising from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans-1,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

2. The spin fluid of claim 1 , wherein the polyolefin is selected from the group consisting of polyethylene, polypropylene, polybutene-1 , poly(4-methyl-1 -pentene), and blends/mixtures thereof:

3. The spin fluid of any one of claims 1 to 2, wherein the at least one linear dr branched hydrocarbon with 5 to 6 carbon atoms is selected from the group consisting of n-pentane. 1 - pentene. 2-methylbutane. n-hexane, 2-methylpentane. 3-methylpentane, 2.2-dimethylbutane. 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

4. The spin fluid of any one of claims 1 to 3, wherein the spin agent comprises from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1, 2-dichloroethylene, and trichloromethane, and from about 70 to about 45 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1-pentene, 2- methylbutane, n-hexane, 2-methylpentane, _; 3-methyipentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

5. A spin flu id for flash spinning comprising (a> from about 9 to about 25 weight percent of a polyolefin, based on the total amount of the spin fluid, and

(b) a spin agent, wherein the spin agent comprises an azeotropic or azeotrope-like composition comprising :

(1 ) dichloromethane and n-pentane, or (2) dichloromethane and 2-methylbutane, or

: (3) trichlbromethane and n-hexane.

6 A process for the preparation of plexifilamentary fibrils of polyolefin which comprises the steps of:

(i) generating a spin fluid comprising

(b) a spin agent, and

(ii) flash spinning the spin fluid ata pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the polymer, wherein the spin agent comprises a composition comprising from about 30 to about 60 weight percent of at least one chlorinated solvent, selected from dichloromethane, trans- 1 ,2-dichloroethylene, cis-1 ,2-dichloroethylene, and trichloromethane, and from about 70 to about 40 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms.

7. ^; The process of claim 6, wherein the polyolefin is selected from the group consisting of polyethylene, polypropylene, polybutene-1, poly(4-methyl-1-pentene), and blends/mixtures thereof.

8. The process of any one of claims 6 to 7, wherein the at least one linear or branched hydrocarbon with 5 to 6 carbon atoms is selected from the group consisting of n-pentane, 1- pentene, 2-methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, 2-methyl-2-butene, 2-methyM -butene, and 1 -hexene.

9. The process of any one of claims 6 to 8, wherein the spin agent comprises from about 30 to about 55 weight percent of at least one chlorinated solvent, selected from dichioromethane, trans- 1.2-dichloroethylene, cis-1 , 2-dichloroethylene, and trichloromethane, and from about 70 to about 55 weight percent of at least one linear or branched hydrocarbon with 5 to 6 carbon atoms, selected from the group consisting of n-pentane, 1 -pentene, 2- methylbutane, n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3- dimethylbutane, 2-methyl-2-butene, 2-methyl-1 -butene, and 1-hexene.

10. A process for the preparation of plexifilamentary fibrils of polyolefin which comprises the steps of:

(i) generating a spin fluid Comprising

(a) from about 9 to about 25 weight percent of a polyolefin, based on the total amount of the spin fluid, and (b) a spin agent, and

(li) flash spinning the spin fluid at a pressure that is above the vapor pressure of the spin fluid into a region of essentially atmospheric pressure to form plexifilamentary fibrils of the polymer, wherein the spin agent comprises an azeotropic or azeotropelike composition comprising

(1) dichloromethane and n-pentane, or

(2) dichloromethane and 2-methylbutane, or

(3) trichloromethane and n-hexane.

11. Use of the spin fluid of any one of claims 1 to 5for preparing of plexifilamentary fibrils of polyolefin by flash spinning.

12. Plexifilamentary fibrils erf polyolefin obtainable by the process of any one of claims 6 to 10;

13 The plexifilamentary fibrils of polyolefin of claim 12 having a BET surface area of from about 5 to about 60 m²/g.

14, A sheet of nonwoven flash-spun plexifilamentary fibrils comprising plexifilamentary fibrils of polyolefin of claim 12 or 13.

15 The sheet of claim 14. wherein the sheet is a collected sheet, a consolidated sheet, a bonded sheet, or a softened sheet.

16. An article comprising the plexifilamentary fibrils of polyolefin of claim 12 or 13 and/or the sheet of claim 14 or 15.

17. The article of claim 16 which is selected from garment, protective apparel, packaging material, house wrap, roof lining, car covers, medical and non-medical packaging, filtration media, print media, tags and labels, and accessories.