WO2025022386A1 - Vitrimers, methods for their production, and uses thereof for compatibilization of polymer blends - Google Patents

Abstract

The present disclosure provides a vitrimer comprising at least two polyolefin backbones, at least one of the at least two polyolefin backbones being connected, at least once, with one other polyolefin backbone of the at least two polyolefin backbones, said connection being via a diester containing bridge. Further provided is a method for obtaining a vitrimer, and a method of polymer compatibilization making use of the vitrimer. Further, provided by the present disclosure is a homogenous polymeric blend comprising at least two synthetic polymers and the disclosed vitrimer, as well as an article of manufacture comprising the vitrimer or the homogenous polymeric blend.

Description

VITRIMERS, METHODS FOR THEIR PRODUCTION, AND USES THEREOF FOR COMPATIBILIZATION OF POLYMER BLENDS

TECHNOLOGICAL FIELD

The present invention relates to compatibilization of polymer blends.

BACKGROUND ART

References considered to be relevant as background to the presently disclosed subject matter are listed below:

Z. P. Zhang, M. Z. Rong, M. Q. Zhang, “Polymer engineering based on reversible covalent chemistry: A promising innovative pathway towards new materials and new functionalities”, Progress in Polymer Science 2018, 80, 39- 93.

- K. M. A. Kaiser, “Recycling of multilayer packaging using a reversible crosslinking adhesive”, J Appl Polym Sci. 2020;137:e49230, https://doi.org/10.1002/app.49230.

International Patent Application Publication No. WO2018028365.

International Patent Application Publication No. WO2020/142578.

International Patent Application Publication No. W02020/160089.

Chinese Patent Application Publication No. CN113337234.

Z. Bauer, "Compatibilization of Polymer Blends Utilizing Vitrimer Chemistry", M.Sc. Thesis, 2022.

R.W. Clarke, T. Sandmeier, K.A. Franklin "Dynamic crosslinking compatibilizes immiscible mixed plastics." Nature 616, 731-739.

Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter. BACKGROUND

Polymer recycling is a process of converting post-consumer or post-industrial waste plastics into useful products or raw materials.

Producing useful materials from heterogenous plastic-containing waste is met with numerous challenges. When different plastic types are combined and melted, they often separate into distinct phases, similar to oil and water, which results in structural weaknesses within the final recycled material. This means that recycled polymer blends created from heterogeneous waste have limited practical applications due to physical weaknesses.

Compatibilization of multi-component polymer blends requires the use of compatibilizers with good property balance, to account for all the interactions among the components. In particular, compatibilization of blends of two or more components resulting from recycled streams is difficult to achieve.

Commercial compatibilizers are usually tuned for a selected polymer family, and good compatibilization is achieved at a narrow range of concentrations. Compatibilizers do not usually allow for compatibilization of multi-component systems due to only partial compatibility with some of the components. Attempts to compatibilize multicomponent systems usually lead to poor mechanical properties of the resulting product.

The challenges of creating robust materials from heterogeneous plastic waste can be overcome using a process known as compatibilization.

Zhang et al (2018) describes reversible covalent chemistry, principles of construction, and properties of reversible covalent polymers.

Kaiser (2020) describes a crosslinked furan-maleimide-functionalized polyurethane to be used as tie layer/adhesive in a polyethylene (PE)/polyethylene terephthalate (PET), PE/ aluminum (Al) or PET/A1 multilayer film. Heating in dimethyl disulfide (DMSO) turns the adhesive into a thermoplastic and leads to its dissolution.

WO2018028365 describes a dynamic polymer having a hybrid cross-linked network structure, with vitrimer dynamic covalent features.

WO2020/142578 describes a self-healing omniphobic composition including a self-healing omniphobic polymer with a crosslinked backbone. W02020/160089 describes a self-healing laminate composition, such a self- healing polymer, when damaged, can undergo autonomous repair when separated surfaces re-contact each other due to the soft nature of the self-healing polymer, whereupon reversible bonds can reform to rejoin and repair the damaged self-healing polymer.

CN113337234 describes a normal-temperature curing epoxy resin-based vitrimer adhesive, which is prepared by mixing a component A epoxy resin and a component B epoxy curing agent.

Z. Bauer (2022) describes synthesis of vitrimer blends with polybutadiene as the majority component, poly(vinylmethylsiloxane-co-dimethylsiloxane) as the minority component, and benzene diboronic ester dithiol as the crosslinker.

R.W. Clarke et al. (2023) describe that designed dynamic crosslinkers can compatibilize mixed-plastics chains (apolar polyolefins and polar polyesters) through dynamic formation of graft multiblock copolymers,

GENERAL DESCRIPTION

The present disclosure is based on the development of a technology that allows for the unexpected and significant improvement of polymer compatibilization. Inter alia, the technology is based on use of vitrimers for compatibilization of polymer blends.

Thus, in a first aspect of the presently disclosed subject matter, there is provided a vitrimer comprising at least two polyolefin backbones, at least one of the at least two polyolefin backbones being connected, at least once, with one other of said at least two polyolefin backbone of the at least two polyolefin backbones, said connection being via a diester containing bridge having a general formula (I)

-L-C(OH)-CH₂-O-C(O)-X-C(O)-O-CH₂-C(OH)-L'- (I) wherein X represents a valence bond or a chemical moiety; wherein L and L', are independently a valence bond or a chemical linker to said polyolefin backbone; and wherein said at least two polyolefin backbones may be the same or different within said vitrimer. In accordance with a second of its aspects, the presently disclosed subject matter provides a masterbatch (MB) composition comprising a polymeric carrier and a vitrimer as disclosed herein.

Also provided by a third aspect of the presently disclosed subject matter is a method for obtaining a vitrimer, the method comprises reacting in a reaction mixture an epoxy containing molecule with an anhydride containing molecule, at least one of said epoxy containing molecule and said anhydride containing molecule is grafted on a polyolefin backbone, said reaction forms a diester containing bridge between one polyolefin backbone and one other polyolefin backbone in said reaction mixture.

Further, in accordance with a fourth aspect, there is provided by the presently disclosed subject matter a method of polymer compatibilization, the method comprising: providing a polymeric mixture comprising at least two incompatible synthetic polymers and a compatibilization agent, and; subjecting said polymeric mixture to mixing under shear forces; wherein said compatibilization agent comprises at least one of

(a) a vitrimer as disclosed herein and at least comprising at least two polyolefin backbones, at least one of the at least two polyolefin backbones being connected, at least once, with one other polyolefin backbone of the at least two polyolefin backbones, said connection being via a diester containing bridge having a general formula (I)

-L-C(OH)-CH₂-O-C(O)-X-C(O)-O-CH₂-C(OH)-L'- (I) wherein X represents a valence bond or a chemical moiety; wherein L and L', are independently a valence bond or a chemical linker to said polyolefin backbone; and wherein said at least two polyolefin backbones may be the same or different within said vitrimer.

(b) a reaction mixture comprising an epoxy containing molecule and an anhydride containing molecule, at least one of said epoxy containing molecule and said anhydride containing molecule is grafted on a polyolefin backbone. Furthermore, the presently disclosed subject matter, provides, in accordance with yet a fifth of its aspects, homogenous polymeric blends comprising at least two different synthetic polymers and a vitrimer as disclosed herein.

Yet further, the presently disclosed subject matter provides, in accordance with a sixth of its aspects, articles of manufacture comprising the presently disclosed vitrimers or the presently disclosed homogenous blends comprising the presently disclosed vitrimer.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 is a diagram describing a mechanism of preparing P-Hydroxy Ester (BHE) composition in accordance with some examples of the present disclosure.

Figure 2 is a plot describing a Fourier Transform Infra-Red (FTIR) spectrum of a P-Hydroxy Ester (BHE) composition according to some examples of the present disclosure.

Figures 3A-3D are graphs of Differential Scanning Calorimetry (DSC) analyses, where Figure 3A is a DSC graph of a neat BHE sample in accordance with the present disclosure; Figure 3B is a DSC graph of BHE-Moprylene (5:95 wt:wt) mixture in accordance with the present disclosure; Figure 3C is a DSC graph of BHE-SW75 (5:95 wt:wt) mixture in accordance with the present disclosure; and Figure 3D is a DSC graph of SW-Bigbagim-BHE mixture (47.5:47.5:5 wt:wt:wt) in accordance with the present disclosure.

DETAILED DESCRIPTION

The process of compatibilization involves adding compatibilizers, which are molecules that can bond to two or more types of plastics and promote their mixing. By using compatibilizers, the plastic types that are incompatible can be made to blend more homogeneously, which can increase the strength and durability of the final composite material.

Vitrimers are group of reversible covalently crosslinked polymers. While in crosslinked state, vitrimers are stable and possess improved mechanical properties similarly to thermosetting polymers. When the crosslinked state is unlocked by an external stimulus (e.g., heating, light, and pH), vitrimers demonstrate true thermoplastic behavior.

The present disclosure is based on the development of a vitrimer for use, inter alia, in compatibilization of polymers.

The term "vitrimer" is used herein to denote a polymer material that has the ability to undergo reversible breaking and reformation of covalent bonds when subjected to a suitable stimulus, such as heat, light, physical trigger (e.g. shear forces), chemical trigger and others.

The presently disclosed subject matter, according to its first aspect, provides a vitrimer comprising at least two polyolefin backbones, at least one of the at least two polyolefin backbones being connected, at least once, with one other polyolefin backbone of the at least two polyolefin backbones, said connection being via a diester containing bridge.

The polyolefin, as used herein, should be understood to have its commonly known meaning, including, a polymer that are derived from polymerization of olefin monomers, such as ethylene, propylene, butene, and hexene and others. In the context of the presently disclosed subject matter, the term "polyolefin" encompasses a homopolymer and a copolymer.

In the context of the presently disclosed subject matter, the term "polyolefin backbone" is to be understood to encompass the polyolefin carbohydrate backbone, however, which can be substituted by heteroatom containing moieties, aromatic moieties and the like, while still maintaining the vitrimer's functionality of being able to undergo the reversible breaking and reformation of covalent bonds.

The at least two polyolefin backbones can represent the same or different polyolefins. In some examples of the present disclosure the least two polyolefin backbones comprise at least two different polyolefins.

As appreciated by those versed in the art of polymer chemistry two different polyolefin molecules can differ from each other based on several factors, including their molecular weight, number of repeating monomer units, tacticity, degree of branching, the presence of comonomers and other factors and combinations of such factors.

In some examples of the presently disclosed subject matter, the at least two polyolefin backbones polyolefins differ in at least one of their monomeric unit.

In some examples of the presently disclosed subject matter, the at least two polyolefin backbones differ in their molecular weight.

In some examples of the presently disclosed subject matter, the at least two polyolefin backbones differ in number of monomeric units.

In some examples of the presently disclosed subject matter, the at least two polyolefin backbones differ in their tacticity. The different polyolefins may, independently, be isotactic, syndiotactic, and atactic.

In some examples of the presently disclosed subject matter, the at least two polyolefin backbones comprise at least one monomeric unit selected from the group consisting of methylene, ethylene, propylene, pentene, octene, butane and any combinations of same, such as ethyl ene-octene, propylene butane.

In some examples of the presently disclosed subject matter, the at least two polyolefin backbones are selected from the group consisting of polyethylene, polypropylene, polymethylpentene, ethylene-octene copolymer, and propyl ene-butane copolymer.

The at least two polyolefin backbones are linked one to the other through a diester containing bridge.

The term "ester bridge" which can be used interchangeably with the term "ester group" or "ester linker are used herein to denote a functional group that contains at least an ester group, i.e. carbonyl group (C=O) bonded to an oxygen atom (O) according to the general formula for an ester is RCOOR', where R and R' can be any alkyl or aryl group. In the context of the presently disclosed subject matter, the bridging between the at least two polyolefin backbones is by a diester bridge, i.e. including two ester groups.

In the context of the presently disclosed subject matter, the diester containing bridge has the general formula (I):

-L-C(OH)-CH₂-O-C(O)-X-C(O)-O-CH₂-C(OH)-L'- (I) wherein X represents a valence bond or a chemical moiety; wherein L and L', are independently a valence bond or a chemical linker to a polyolefin backbone.

In some examples of the presently disclosed subject matter, X is an organic moiety.

In some examples of the presently disclosed subject matter, X is an organic moiety comprising any one or combination of an aliphatic chain, an aliphatic ring and an aromatic ring, the chain or ring optionally including one or more heteroatoms.

In some examples of the presently disclosed subject matter, X comprises an aromatic ring.

In some examples of the presently disclosed subject matter X, comprises or is a phenyl ring.

In some examples of the presently disclosed subject matter, L and L' are be same or different within a single vitrimer.

In some examples of the presently disclosed subject matter, L and L' are the same.

In some examples of the presently disclosed subject matter, L and L' are different.

In some examples of the presently disclosed subject matter, at least one of L and L' comprises or is a carbonyl group.

In some examples of the presently disclosed subject matter, at least one of L and L' comprises any one of an aliphatic chain, an aliphatic ring, an aromatic ring, and any combinations of same, the chain or ring optionally including a heteroatom.

In some examples of the presently disclosed subject matter, L or L' comprise independently an acrylate moiety (i.e. an acrylate moiety which may be the same or different within the diester bridge). In some examples of presently disclosed subject matter, L or L' comprise independently an acrylate moiety selected from the group consisting of alkyl acrylate, alkyl methacrylate, acrylic acid and methacrylic acid.

In some examples of the presently disclosed subject matter, L and L' are both methacrylate.

In some examples of the presently disclosed subject matter, X is a phenyl ring and L and L' are both methacrylate. Hence, in some examples of the presently disclosed subject matter, the chemical bridge has the formula (II):

The vitrimer according to the presently disclosed subject matter forms a crosslinked three-dimensional network structure. Cross-linking involves the formation of covalent bonds between polyolefin chains, which results in the formation of a network comprising a plurality of polyolefin backbones being cross-linked one to another through a plurality of said diester containing bridges.

The vitrimer, according to the presently disclosed subject matter, can be characterized by a degree of crosslinking.

The term "degree of crosslinking" is used to denote the extent to which a polymer network comprising the presently disclosed vitrimer is interconnected through covalent ester bonds between individual polyolefin backbones. The degree of crosslinking is a measure of the density of these ester bonds, and can be expressed in terms of the number or weight of crosslinks per unit volume or mass of the polymer network.

In some examples of the presently disclosed subject matter, the degree of crosslinking is represented as the fraction of monomers in the polymer that have been crosslinked and expressed in mole%. In some examples of the presently disclosed subject matter, the degree of crosslinking of the vitrimer is within a range of about 0.1 mole% and about 10 mole%.

The degree of crosslinking of the presently disclosed vitrimers can be measured by any one of Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA) or Nuclear Magnetic Resonance (NMR).

In some examples of the presently disclosed subject matter, the degree of crosslinking is indirectly evaluated by analyzing the dynamic viscosity of the crosslinked network of polymers. Without being bound by theory, when the degree of crosslinking increases, the viscosity of the vitrimer also increases, reflecting the increased density of the covalent bonds in the polymer network.

The term "dynamic viscosity" or "absolute viscosity" is used to denote measure of material's resistance to flow under an applied force or stress. It is defined as the ratio of the shear stress to the shear rate in a material, expressed in units of Pascal-seconds (Pa s) or centipoise (cP).

In some examples of the presently disclosed subject matter, the dynamic viscosity of the presently disclosed vitrimers are within a range of about 10² to 10⁶ Pa s when measured at 1 Hz/sec'¹ and about 10¹ to 10⁴ Pa s when measured at 100 Hz/sec'¹, at times between about 500 to 7000 Pa s when measured at 10 Hz/sec'¹.

To facilitate the use of the presently disclosed vitrimers, the vitrimer(s) can be a priori formed into a masterbatch. It has been found that it is possible to homogeneously blend the presently disclosed vitrimers with a variety of synthetic polymeric carriers to be used as masterbatch (MB) formulations.

In some examples of the presently disclosed subject matter, such masterbatch formulation can be formed into pellets, as further described hereinbelow.

Thus, the presently disclosed subject matter provides, in accordance with a second aspect thereof, a MB comprising the presently disclosed vitrimer(s) blended with one or more synthetic polymeric carriers.

In some examples of the presently disclosed subject matter, the polymeric carrier is characterized by a first viscosity and a vitrimer is characterized by a second viscosity. In some examples of the presently disclosed subject matter, the first viscosity, i.e. that of the polymeric carrier, is lower than the second viscosity, i.e. of the vitrimer.

In some examples of the presently disclosed subject matter, the polymeric carrier within the MB comprises one or more polyolefins.

In some examples of the presently disclosed subject matter, the one or more polyolefins in the MB is selected from the group consisting of polyethylene (PE), polypropylene (PP), polyvinyl, polyvinyl alcohol, polyvinyl pyridine, polyolefin styrene and combinations of same.

In some examples of the presently disclosed subject matter, the polymeric carrier comprises a polyolefin that is identical to at least one of the at least two polyolefin backbones of the presently disclosed vitrimer.

In some examples of the presently disclosed subject matter, the polymeric carrier comprises a combination of polymers, at least one being other than a polyolefin, such as polyester, polyamide, EVOH and polyurethane.

The amount of the vitrimer in the MB can vary depending on the specific need of the MB. The amount of the vitrimer can be defined by the weight ratio between the polymeric carrier and the vitrimer.

In some examples of the presently disclosed subject matter, the weight ratio between the polymeric carrier and the vitrimer ranges from about 99: 1 to about 50:50; at times from about 99: 1 to about 97:3; at times from about 98:2 to about 96:4; at times from about 95:5 to about 93:7; at times from about 92:8 to about 90: 10; at times from about 89: 11 to about 87: 13; at times from about 86: 14 to about 84:16; at times from about 83: 17 to about 81 : 19; at times from about 80:20 to about 78:22; at times from about 77:23 to about 75:25; at times from about 74:26 to about 72:28; at times from about 71 :29 to about 69:31; at times from about 68:32 to about 66:34; at times from about 65:35 to about 63:37; at times from about 62:38 to about 60:40; at times from about 59:41 to about 57:43; at times from about 56:44 to about 54:46; at times from about 53 :47 to about 51 :49; at times from about 49:51 to about 47:53; at times from about 46:54 to about 44:56; at times from about 43 :57 to about 41 :59; at times from about 40:60 to about 38:62; at times from about 37:63 to about 35:65; at times from about 34:66 to about 32:68; at times from about 31 :69 to about 29:71; at times from about 28:72 to about 26:74. In some examples of the presently disclosed subject matter, the vitrimer and for the same reason, the MB may comprise trace amounts of a catalyst. The presence of trace amounts of a catalyst is due to the involvement of a catalyst in the process of obtaining the presently disclosed vitrimer.

In some examples of the presently disclosed subject matter, the trace amounts of the catalyst can include trace amounts of an element selected from the group consisting of Zinc (Zn), Tin (Sn), Cobalt (Co) and combinations of same.

In some examples of the presently disclosed subject matter, the catalyst of which trace amounts can be found in the vitrimer and/or MB comprises ionic and organometallic compounds containing at least one of zinc (Zn), tin (Sn) and cobalt (Co).

In some examples of the presently disclosed subject matter, the catalyst is selected from the group consisting of zinc acetate, cobalt acetate, cobalt phthalocyanine, zinc phthalocyanine, tin octoate and combinations of same.

In some examples of the presently disclosed subject matter, the catalyst is zinc acetate.

In accordance with a third aspect of the presently disclosed subject matter, there is also provides a method of producing the presently disclosed vitrimer. The presently disclosed method comprises reacting in a reaction mixture an epoxy containing molecule with an anhydride containing molecule, at least one of said epoxy containing molecule and said anhydride containing molecule is grafted on a polyolefin backbone, said reaction forms a diester containing bridge between one polyolefin backbone and one other polyolefin backbone in said reaction mixture.

In accordance with the present disclosure, all terms and definitions provided hereinabove in connection with the vitrimer also apply, mutatis mutandis, to the presently disclosed MB and presently disclosed method.

The term "grafting" or "grafted" is used to denote the covalent association with the polyolefin backbone.

In accordance with some examples of the presently disclosed subject matter, the molecule which is grafted on the polyolefin backbone is an epoxy containing molecule. In accordance with some examples of the presently disclosed subject matter, the molecule which is grafted on the polyolefin backbone is an anhydride containing molecule.

In accordance with some examples of the presently disclosed subject matter, the epoxy molecule is grafted onto a first polyolefin backbone and the anhydride containing molecule is grafted onto a second polyolefin backbone.

In some examples the first polyolefin backbone associated with the epoxy containing molecule and the second polyolefin backbone that is associated with the anhydride containing molecule are the same.

In some examples the first polyolefin backbone associated with the epoxy containing molecule and the second polyolefin backbone that is associated with the anhydride containing molecule are different.

In some examples of the presently disclosed subject matter, the one (e.g. first) polyolefin backbone and the one other (e.g. second) polyolefin backbone in the reaction mixture are, independently from each other, selected from the group comprising polyethylene, polypropylene, polymethylpentene, ethylene-octene copolymer, and propyl ene-butane copolymer.

In some examples the polyolefin backbone, onto which the epoxy containing molecule and/or the anhydride containing molecule is grafted, is polyethylene.

It is appreciated by a person skilled in the art of polymer chemistry that an anhydride group/moiety or an epoxy group/moiety can be grafted on a polyolefin backbone with varying degree of grafting efficiency or grafting density.

The terms "grafting efficiency" or "grafting density" or "grafting ratio" can be used interchangeably to denote density of grafted molecules (e.g. the epoxy containing molecule and the anhydride containing molecule) per unit length or mass of the polymer chain (in the present disclosure, polyolefin backbone) and is expressed as a percentage or a number of grafted molecules per repeating unit of the polymer chain.

In some examples of the presently disclosed subject matter, the epoxy containing molecule is grafted on a polyolefin backbone with grafting efficiency within a range of about 0.5% to about 5%; at times between about 0.5% to about 1.0%; at times between about 0.9% to about 1.5%; at times between about 1.4% to about 2.0%; at times between about 1.9% to about 2.5%; at times between about 2.4% to about 3.0%; at times between about 2.9% to about 3.5%; at times between about 3.4% to about 4.0%; at times between about 3.9% to about 4.5%; at times between about 4.4% to about 5.0%.

In some examples of the presently disclosed subject matter, the anhydride containing molecule is grafted on polyolefin backbone with grafting efficiency within a range of about 0.5% to about 5%, at times between about 0.5% to about 1.0%; at times between about 0.9% to about 1.5%; at times between about 1.4% to about 2.0%; at times between about 1.9% to about 2.5%; at times between about 2.4% to about 3.0%; at times between about 2.9% to about 3.5%; at times between about 3.4% to about 4.0%; at times between about 3.9% to about 4.5%; at times between about 4.4% to about 5.0%.

In some examples of the presently disclosed subject matter, the epoxy containing molecule and the anhydride containing molecule (irrespective of which is grafted on the polyolefin backbone) are present in the reaction mixture at any molar ratio, i.e. at a molar ratio between the epoxy moiety and anhydride moiety of between about 100: 1 and about 1 : 100.

In some examples of the presently disclosed subject matter, the epoxy containing molecule is selected from the group comprising glycidyl monomethacrylate, glycidyl dimethacrylate, glycidyl methacrylate, allyl glycidyl ether, and t-Butyl glycidyl ether.

In some examples of the presently disclosed subject matter, the epoxy containing molecule is glycidyl methacrylate.

In some examples of the presently disclosed subject matter, the anhydride containing molecule is selected from the group comprising phthalic anhydride, maleic anhydride, succinic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, 4- methylethynyl phthalic anhydride and combinations thereof.

In some examples of the presently disclosed subject matter, the anhydride containing molecule is phthalic anhydride.

In some examples of the presently disclosed subject matter, the reaction mixture further comprises a polymeric carrier. The polymeric carrier is to be understood to have the same meaning as provided in the context of the presently disclosed MB. In some examples the polymeric carrier is in amount of between about 20 wt% to about 90 wt% out of a total weight of the reaction mixture; at times between about 20.0 wt% to about 25.0 wt%; at times between about 24.0 wt% to about 30.0 wt%, at times between about 29.0 wt% to about 35.0 wt%; at times between about 34.0 wt% to about 40.0 wt%; at times between about 39.0 wt% to about 45.0 wt%; at times between about 44.0 wt% to about 50.0 wt%; at times between about 49.0 wt% to about 55.0 wt%; at times between about 54.0 wt% to about 60.0 wt%; at times between about 59.0 wt% to about 65.0 wt%; at times between about 64.0 wt% to about 70.0 wt%; and at times between about 69.0 wt% to about 78.0 wt%; at times between about 75.0 wt% to about 85.0 wt%; at times between about 83.0 wt% to about 90.0 wt%.

In some examples of the presently disclosed subject matter, the reaction mixture comprises a catalyst.

In some examples of the presently disclosed subject matter, the catalyst of the reaction mixture comprises ionic and organometallic compounds containing at least one of zinc (Zn), tin (Sn) and cobalt (Co).

In some examples of the presently disclosed subject matter, the catalyst is selected from the group consisting of zinc acetate, cobalt acetate, cobalt phthalocyanine, zinc phthalocyanine, tin octoate and combinations of same.

In some examples of the presently disclosed subject matter, the catalyst is zinc acetate.

In some examples of the presently disclosed subject matter, the method of producing vitrimer comprises subjecting the reaction mixture to high-shear mixing.

In some examples of the presently disclosed subject matter, the high shear mixing comprises extrusion.

In some examples of the presently disclosed subject matter, the high shear mixing comprises injection molding.

The presently disclosed vitrimers can be used for polymer compatibilization. In accordance with a fourth aspect of the presently disclosed subject matter, there is thus provided a method of polymer compatibilization.

In accordance with this fourth aspect, the disclosed method comprises: providing a polymeric mixture comprising at least two incompatible synthetic polymers and a compatibilization agent, and; subjecting the polymeric mixture to mixing under shear forces; wherein said compatibilization agent comprises at least one of

(i) the presently disclosed vitrimer, i.e. a vitrimer comprising at least two polyolefin backbones, at least one of the at least two polyolefin backbones being connected, at least once, with one other polyolefin backbone of the at least two polyolefin backbones, said connection being via a diester containing bridge having a general formula (I)

-L-C(OH)-CH₂-O-C(O)-X-C(O)-O-CH₂-C(OH)-L'- (I) wherein X represents a valence bond or a chemical moiety; wherein L and L', are independently a valence bond or a chemical linker to said polyolefin backbone; and wherein said at least two polyolefin backbones may be the same or different within said vitrimer; and

(ii) the presently disclosed masterbatch, i.e. a reaction mixture of an epoxy containing molecule and an anhydride containing molecule, at least one of said epoxy containing molecule and said anhydride containing molecule is grafted on a polyolefin backbone.

It is to be understood that all terms and definitions provided hereinabove in connection with the vitrimer, the MB and the method of obtaining the vitrimer/MB also apply, mutatis mutandis, to the presently disclosed method for polymer compatibilization.

The terms "polymer compatibilization" or "compatibilization" as used herein denote a process of modifying the interface between two or more polymers that are typically incompatible, such that they can be blended together to form a homogeneous mixture or composite.

The term "incompatible polymers" as used herein denotes two or more polymers that do not readily mix or dissolve in each other as a result of, e.g. differences in their chemical nature, molecular structure, intermolecular forces and other factors. In some examples of the presently disclosed subject matter, when two or more incompatible polymers are blended together in the absence of the presently disclosed vitrimer or presently disclosed MB, the incompatibility presents itself as phase separation aggregation or precipitation.

In some examples of the presently disclosed subject matter, the at least two incompatible polymers comprise at least one recycled synthetic polymer.

In some examples of the presently disclosed subject matter, the at least two incompatible polymers comprise heterogenous plastic waste.

In some examples of the presently disclosed subject matter, the at least two incompatible polymers comprise at least one polyolefin and at least one non-polyolefin.

In some examples of the presently disclosed subject matter, the at least two incompatible polymers comprise at least one polyolefin selected from the group consisting of polyethylene (PE) and polypropylene (PP).

The at least two incompatible polymers comprise at least one polyolefin selected from the group consisting of Polyethylene terephthalate (PET), Polyvinyl chloride (PVC), Polystyrene (PS), Polyethylene oxide (PEO), Polyurethane (PU), Polycarbonate (PC), Polyethylene glycol (PEG), Poly(methyl methacrylate) (PMMA), Polyvinylidene fluoride (PVDF), Polyamide (PA/Nylon), Polyimide (PI), Polyethylene naphthalate (PEN), Polybutadiene (PBD), Polyphenylene oxide (PPO), Polysulfone (PSU), Polyethylene terephthalate glycol (PETG), Polyetheretherketone (PEEK), Polyacrylonitrile (PAN), Polyvinyl acetate (PVAc), Polyvinyl alcohol (PVA), Polyvinyl butyral (PVB), Polypropylene carbonate (PPC), Polylactic acid (PLA), Polyoxymethylene (POM), Polyisoprene (IR), Polyvinyl pyrrolidone (PVP), Polydimethylsiloxane (PDMS), Polyvinyl fluoride (PVF), Polyoxyethylene (POE), Polyoxypropylene (POP), Polyoxymethylene copolymer (POMC), Polymethylpentene (PMP), Polyvinyl carbazole (PVK), Polyvinylidene chloride (PVDC), Polyisobutylene (PIB), Polytetrafluoroethylene (PTFE), Polyetherimide (PEI), Polypropylene oxide (PPOx), Polypropylene sulfide (PPS), Polyvinylpyridine (PVPy), Polyetheresterketone (PEEK), Polyethylene succinate (PES), Polyethylene isophthalate (PEI), Polypropylene fumarate (PPF), Polyethylene terephthalate isophthalate (PETI), Polycaprolactone (PCL), Polyvinylsulfonic acid (PVSA), Polyvinyl butyrate (PVB), Polyphenylene sulfide (PPS), Polyoxybutylene (POB), Polyvinyl formal (PVF), Polyvinylidene fluoridetrifluoroethylene (PVDF-TrFE), Polyvinylpyrrolidone-vinyl acetate copolymer (PVP- VA), Polyester, Ethylene Vinyl Alcohol (EVOH), Polyacrylate (PA), Polycarbonate (PC), Polystyrene (PS), and Polyurethane (PU).

The presently disclosed subject matter also provides, in accordance with its fifth aspect, a compatibilized plastic material comprising a homogenous blend comprising at least two synthetic polymers and the presently disclosed vitrimer, wherein the at least two synthetic polymers are incompatible one with the other in the absence of said vitrimer.

The use of the presently disclosed vitrimer in the compatibilized plastic material can be determined by identifying the presence of the diester bridge. This can be achieved using, inter alia, FTIR, NMR, XPS, Raman spectroscopy, quantitative chemical analysis, and dissolution/swelling tests.

It is to be understood that all terms and definitions provided hereinabove in connection with the vitrimer, the MB and the disclosed methods also apply, mutatis mutandis, to the presently disclosed compatibilized plastic material.

In some examples of the presently disclosed subject matter, the compatibilized plastic material disclosed herein has been shown to have one or any combination of advantageous physical properties, these include, inter alia, density, melt flow index (MFI), Notched Izod Impact, Un-Notched Izod Impact, tensile strength, and tensile elongation.

In some examples of the presently disclosed subject matter, the compatibilized plastic material is defined by having a specific density level. In the context of the present disclosure when referring to density of the compatibilized plastic material it is to be understood as density of the compatibilized plastic material being equal or less than 1.0gr/cm³, at times, between about 0.92 and about 0.98 gr/cm³; at times between about 0.73 about 0.80 gr/cm³.

The density of the compatibilized plastic material can be determined using ASTM D792 or ISO 1183 standards, as further described below in connection with the Examples, which form an integral part of the present disclosure.

In some other examples of the presently disclosed subject matter, the compatibilized plastic material is defined by its Notched Izod Impact. In the context of the present disclosure, when referring to Notched Izod Impact of the compatibilized plastic material disclosed herein it is to be understood as one being at least 40J/m.

Without being limited thereto, the Notched Izod Impact, which is a measurement of resistance of the compatibilized plastic material to impact from a swinging pendulum wherein a V-shaped notch is cut into the specimen to create a stress concentration point, can be determined using ASTM D256 (ISO 180) as further described below in connection with the Examples, which form an integral part of the present disclosure.

In some examples of the presently disclosed subject matter, the Notched Izod Impact of the compatibilized plastic material is at least 40J/m; at times at least 50J/m; at times at least 60J/m; at times at least 70J/m, at times at least 80J/m; at times at least 90J/m, at times at least 100J/m; at times at least 1 lOJ/m; at times, of at least 125J/m; at times, of at least 150J/m; at times, of at least 175J/m; at times, of at least 200J/m; at times, of at least 225 J/m; at times, of at least 250 J/m;.

In some examples of the presently disclosed subject matter, the Notched Izod Impact is within the range of 40J/m and 300J/m; at times within the range of 40J/m and 275J/m.

In some examples of the presently disclosed subject matter, the compatibilized plastic material is defined by its Unnotched Izod Impact. The Unnotched Izod Impact, which is a measurement of resistance of the compatibilized plastic material to impact from a swinging pendulum without a notch, can be determined using ASTM D256 (ISO 180) as further described below in connection with the Examples, which form an integral part of the present disclosure.

In some examples of the presently disclosed subject matter, the Unnotched Izod Impact of the compatibilized plastic material disclosed herein is at least 700J/m.

In some examples of the presently disclosed subject matter, the Unnotched Izod Impact of the presently disclosed compatibilized plastic material is at least 750J/m; at times at least 800 J/m; at times at least 900 J/m; at times at least 1000 J/m; at times at least 1 100J/m; at times partial break (PB); at times hinge break (HB); at times no break (NB).

In some examples of the presently disclosed subject matter, the Unnotched Izod Impact is within the range of 700J/m and 800J/m, at times within the range of 800J/m and 900 J/m, at times within the range of 900 J/m and 1000 J/m; at times within the range of 1000J/m and 1100J/m; at times partial break (PB); at times hinge break (HB); at times no break (NB).

In some examples of the presently disclosed subject matter, the compatibilized plastic material is characterized by its tensile strength. The tensile strength, which is a measurement of the maximum stress that a material can withstand before breaking under tension or pulling forces, can be determined using ASTM D638 as further described below in connection with the Examples, which form an integral part of the present disclosure.

In some examples of the presently disclosed subject matter, the tensile strength of the compatibilized plastic material disclosed herein is at least 20MPa.

In some examples of the presently disclosed subject matter, the tensile strength of the compatibilized plastic material is at least 20MPa; at times at least 30MPa; at times at least 40MPa; at times at least 50MPa; at times at least 60MPa.

In some examples of the presently disclosed subject matter, the tensile strength is within the range of 20MPa and 60MPa; at times between about 20 MPa to about 28 MPa; at times between about 26 MPa to about 34 MPa; at times between about 32 MPa to about 40 MPa; at times between about 38 MPa to about 46 MPa; at times between about 44 MPa to about 60 MPa.

In some examples of the presently disclosed subject matter, the compatibilized plastic material is characterized by its Flexural Modulus. The flexural modulus, which is a measurement of a material's resistance to bending or deformation under load, can be determined using ISO 178 or ASTM D790 standards as further described below in connection with the Examples, which form an integral part of the present disclosure.

In some examples of the presently disclosed subject matter, the flexural modulus of the compatibilized plastic material disclosed herein is at least 600MPa.

In some examples of the presently disclosed subject matter, the flexural modulus of the compatibilized plastic material is at least 600MPa; at times at least 700MPa; at times at least 800MPa; at times at least 900MPa; at times at least 100OMPa; at times at least 1 100MPa; at times at least 1200MPa. In some examples of the presently disclosed subject matter, the flexural modulus is within the range of 600MPa and 2000MPa; at times, between about 600 MPa to about 820 MPa; at times, between about 800 MPa to about 1020 MPa; at times, between about 1000 MPa to about 1220 MPa; at times, between about 1200 MPa to about 1420 MPa; at times between about 1400 MPa to about 1620 MPa; at times, between about 1600 MPa to about 1820 MPa; at times, between about 1800 MPa to about 2000 MPa.

In some examples of the presently disclosed subject matter, the compatibilized plastic material is characterized by its Tensile Elongation. Tensile elongation, which is a measurement of the percentage increase in length of a material sample when it is stretched to its breaking point during a tensile test, can be determined using ISO 527 or ASTM D638 standards as further described below in connection with the Examples, which form an integral part of the present disclosure.

In some examples of the presently disclosed subject matter, the tensile elongation of the compatibilized plastic material disclosed herein is at least 5%.

In some examples of the presently disclosed subject matter, the tensile elongation of the compatibilized plastic material is at least 10%; at times at least 20%, at times at least 30%, at times at least 40%, at times at least 80%, at times at least 120%, at times at least 180%.

In some examples of the presently disclosed subject matter, the tensile elongation of the presently disclosed compatibilized plastic material is within the range of 10% and 400%; at times between about 20% to about 75%; at times between about 70% to about 125%; at times between about 120% to about 175%; at times between about 170% to about 225%; at times between about 220% to about 275%; at times between about 270% to about 400%.

The compatibilized plastic material can be part of an article of manufacture. In other words, the presently disclosed vitrimer or the presently disclosed MB can be used for the production of different articles of manufacture.

The article of manufacture can be obtained by any technique known, e.g. in the plastic industry. For example, and without being limited thereto, the vitrimer or MB can be incorporated into one or more of the processing techniques including extrusion, molding (injection molding, compression molding, extrusion, blown film). In some examples of the presently disclosed subject matter, the disclosed article of manufacture comprises a blend, preferably a homogenous blend of the presently disclosed vitrimer and at least one plastic material (e.g. thermoplastic polymer).

It is appreciated that presently disclosed vitrimer or a masterbatch comprising thereof can be used as a tie layer. As used herein the term "tie layer" refers to an intermediate layer that is used to bond or "tie" together two incompatible materials or polymers that would otherwise have poor adhesion or compatibility with each other. It acts as a bridge between two dissimilar materials, promoting adhesion and enhancing the overall performance of a multilayered structure.

Hence in some examples of the presently disclosed subject matter, the disclosed article of manufacture comprises a multilayer structure having a first component (e.g. layer) of a first polymeric material and a second component (e.g. layer) of a second polymeric material, and a compatibilizer comprising the presently disclosed vitrimer or MB interposed between the first component and the second component.

In some examples of the presently disclosed subject matter, the first polymeric component and the second polymeric component are incompatible one with each other.

In some examples of the presently disclosed subject matter, at least one of the first polymeric component and the second polymeric component is polyolefin.

In some examples of the presently disclosed subject matter, at least one of the first polymeric component and the second polymeric component is non-polyolefin.

In some examples the at least one non-polyolefin in the article of manufacture (e.g. the first or second component thereof) is selected from the group consisting of polyamide, polyester, EVOH, polyacrylate, polycarbonate, polystyrene, and polyurethane Polyethylene terephthalate (PET), Polyvinyl chloride (PVC), Polystyrene (PS), Polyethylene oxide (PEO), Polyurethane (PU), Polycarbonate (PC), Polyethylene glycol (PEG), Poly(methyl methacrylate) (PMMA), Polyvinylidene fluoride (PVDF), Polyamide (PA/Nylon), Polyimide (PI), Polyethylene naphthalate (PEN), Polybutadiene (PBD), Polyphenylene oxide (PPO), Polysulfone (PSU), Polyethylene terephthalate glycol (PETG), Poly ether etherketone (PEEK), Polyacrylonitrile (PAN), Polyvinyl acetate (PVAc), Polyvinyl alcohol (PVA), Polyvinyl butyral (PVB), Polypropylene carbonate (PPC), Polylactic acid (PLA), Polyoxymethylene (POM), Polyisoprene (IR), Polyvinyl pyrrolidone (PVP), Polydimethylsiloxane (PDMS), Polyvinyl fluoride (PVF), Polyoxyethylene (POE), Polyoxypropylene (POP), Polyoxymethylene copolymer (POMC), Polymethylpentene (PMP), Polyvinyl carbazole (PVK), Polyvinylidene chloride (PVDC), Polyisobutylene (PIB), Polytetrafluoroethylene (PTFE), Polyetherimide (PEI), Polypropylene oxide (PPOx), Polypropylene sulfide (PPS), Polyvinylpyridine (PVPy), Polyetheresterketone (PEEK), Polyethylene succinate (PES), Polyethylene isophthalate (PEI), Polypropylene fumarate (PPF), Polyethylene terephthalate isophthalate (PETI), Polycaprolactone (PCL), Polyvinylsulfonic acid (PVSA), Polyvinyl butyrate (PVB), Polyphenylene sulfide (PPS), Polyoxybutylene (POB), Polyvinyl formal (PVF), Poly vinylidene fluoride-trifluoroethylene (PVDF- TrFE), Polyvinylpyrrolidone-vinyl acetate copolymer (PVP-VA).

The vitrimer should not be limited to specific uses and impact can be employed in any situation where the resulting characteristics of the polymer blend or the recyclability of a product can be improved. Thus, it is to be understood that the presently disclosed aspects can be utilized in different fields where there is a need for compatibilization of incombatible materials. In some preferred cases, the presently disclsoed subject matter can be utilized in the plastic industry, in the recycling industry, in the waste management industry etc.

As used herein, the forms "a", "an" and "the" include singular as well as plural references unless the context clearly dictates otherwise. For example, the term "vitrimer" includes one or more vitrimers as defined and disclosed herein.

Further, as used herein, the term "comprising" is intended to mean that, for example, a composition or combination includes the recited components, e.g. a polymer and a vitrimer, but not excluding other elements. The term "consisting essentially of' shall mean that, e.g. the composition or combination includes the recited components, e.g. a polymer and a vitrimer, and not more than trace elements of other elements. The term "consisting of' shall mean excluding more than trace elements of other elements. Embodiments defined by each of these transition terms are within the scope of this invention.

Further, all numerical values, e.g. the amounts or ranges of the components constituting the presently disclosed subject matter are approximations which are varied (+) or (-) by up to 20%, at times by up to 10% of from the stated values. It is to be understood, even if not always explicitly stated that all numerical designations are preceded by the term "about". For example, the term "about 10%" should be understood as encompassing the range of 9% to 11%.

The invention will now be exemplified in the following description of experiments that were carried out in accordance with the invention. It is to be understood that these examples are intended to be in the nature of illustration rather than of limitation. Obviously, many modifications and variations of these examples are possible in light of the above teaching. It is therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise, in a myriad of possible ways, than as specifically described hereinbelow.

DESCRIPTION OF SOME NON-LIMITING EXAMPLES

Materials

Glycidyl-methacrylate-grafted polyethylene (PE-g-GMA) (Lotader AX8840 with 8 wt% GMA groups) was purchased from Arkema, France.

- Phthalic anhydride was purchased from Sigma-Aldrich, Israel.

Virgin Polypropylene (vPP) was purchased from Carmel Olefins, Israel

- Recycled Polypropylene (rPP) was purchased from Morssinkhof, Netherlands.

Multilayer films comprising layers of PET, EVOH, polyamide, polyolefin, polyurethane were supplied as post-industrial waste by Plastopil HaZorea Ltd., Israel.

Methods

Notched Izod Impact - ASTM D256

Unnotched Izod Impact - ASTM D4812

Tensile Strength, Modulus and Strain to Break - ASTM D638

- Melt Flow Index - ASTM D 1238

FTIR - ASTM E1252 or ASTM E168

DSC - ASTM D3418 EXAMPLE 1: Preparing β-Hydroxy Ester (BHE) composition by reactive extrusion

A P-Hydroxy Ester (BHE) composition was prepared by reactive extrusion of a glycidyl-methacrylate-grafted polyethylene (PE-g-GMA) with phthalic anhydride in a polyolefin matrix. Figure l is a diagram describing a mechanism of preparing P-Hydroxy Ester (BHE).

95 wt% of polypropylene (SW75, Carmel Olefins, Israel) were dry-mixed with 5 wt% of BHE components (95 wt% PE-g-MA, 3.8 wt% PA and 1.2 wt% Zn(CH₃COO)₂. The mixture was then compounded in a PRISM twin screw extruder (L\D 40) at 190 °C, 200 RPM.

The composition, structure and ester bond formation were elucidated by FTIR and DSC.

The FTIR spectrum in Figure 2 shows characteristic peaks at around 900 [cm^-1] for an aromatic ring (derived from phthalic anhydride) and at approximately 1100 cm^-1] and 1740 cm^-1] , which correspond to -OH and C=O groups, respectively. The latter peak is indicative of the formation of an ester bond.

Figure 3A shows the DSC thermograms of a neat BHE sample - 1^st heating, cooling and re-crystallization, and 2^nd heating.

Figure 3B shows the heating/cooling thermograms of BHE-Moprylene (5:95 wt:wt) mixture.

Figure 3C shows the heating/cooling thermograms of BHE-SW75 (5:95 wt:wt) mixture.

Figure 3D shows the heating/cooling thermograms of SW-Bigbagim-BHE mixture (47.5:47.5:5 wt:wt:wt). “Bigbagim” are recycled PE:PP plastic bags from the construction industry.

Figures 3A-3D show the melting peaks during 1^st heating cycle, the crystallization peaks during cooling, and the re-melting peaks during 2^nd heating cycle.

EXAMPLE 2: Compatibilization of Virgin Polypropylene and Recycled Polypropylene (rPP)

The BHE composition as in Example 1 was used to compatibilize blends of Virgin Polypropylene (vPP) and Recycled Polypropylene (rPP). 95 wt% of mixed polyolefins (see below) were dry -mixed with 5 wt% of BHE components (95 wt% PE-g-MA, 3.8 wt% PA and 1.2 wt% Zn(CH₃COO)₂. The mixture was then compounded in a PRISM twin screw extruder (L\D 40) at 190 °C, 200 RPM.

Several mixed polyolefins were used:

A. 50:50 (wt:wt) of polypropylene (SW75, Carmel Olefins, Israel) and recycled polypropylene (Moprylene PP Z1CCPHHM grey 939, Morssinkhof- Rymoplast).

B. 50:50 (wt:wt) polypropylene (R50, Carmel Olefins, Israel) and recycled polypropylene (Moprylene PP Z1CCPHHM grey 939, Morssinkhof- Rymoplast).

C. 50:50 (wt:wt) of polypropylene (SW75, Carmel Olefins, Israel) and a recycled multi-layer film G51 (a mix of polyethylene, poly(ethylene terephthalate), nylon 6).

D. 50:50 (wt:wt) of polypropylene (SW75, Carmel Olefins, Israel) and a recycled PE:PP (50:50, “Bigbagim”, i.e. used plastic bags from the construction business).

E. 50:50 (wt:wt) of recycled polypropylene (Moprylene PP Z1CCPHHM grey 939, Morssinkhof-Rymoplast) and a recycled multi-layer film G51 (a mix of polyethylene, poly(ethylene terephthalate), nylon 6).

F. 100 % recycled polypropylene (Moprylene PP Z1CCPHHM grey 939, Morssinkhof-Rymoplast) as the 95 wt% polyolefin matrix.

The compositions of some of the blends are given in Table 1 and Table 3.

Table 1: Composition of compatibilized vPP and rPP blends

The physical properties of the blends are summarized in Table 2.

Table 2: Physical/mechanical properties of compatibilized vPP and rPP blends

Test results of "Izod Un Notched" and "Izod Notched" may include also any one of PB (partial break), NB (no break), CB (complete break), HB (hinge break), all being according to ASTM D256.

Table 3: Composition of compatibilized rPP and polyblends

Compounded in a PRISM twin screw extruder (L\D 40) at 190°C, 200 RPM

** compounded in an APV industrial twin-screw extruder

*** a polyblend from recycled multilayer packaging

**** SW75 by Carmel Olefins Table 4: Physical/mechanical properties of compatibilized rPP or polyblends

The notched impact strength increased up to several-fold and the unnotched impact resistance also increased and is of the no break (NB) type, with only 5wt% BHE in 80rPP/20poly or 60rPP/20SW75/20poly. The flow of the compositions remained high, with typical Melt Flow Index (MFI) values of 15 (230°C/2.16 kg).

EXAMPLE 3: Compatibilization of Polyethylene and Polypropylene

The same BHE composition as in Example 1 was used to compatibilize blends of

PE and PP, either virgin or recycled, using the blending procedure as described in Example 2.

The compositions of the blends are given in Table 5.

Table 5: Composition of compatibilized PE and PP blends

The physical properties of the blends are summarized in Table 6.

Table 6: Physical properties of PE and PP blends

For the vPP/rPP blend, the notched impact resistance increased by 30% and the unnotched impact resistance almost doubled with only 5wt% BHE.

An rPP/rPE blend was blended with vPP at 50%. The addition of 5% BHE led to an increase of 10% in impact resistance, with minor effect on MFI, while keeping the tensile strength above that of the benchmark SW75 (21.5 MPa). EXAMPLE 4: Compatibilization of multipolymer blends

The BHE composition as in Example 1 was used to compatibilize blends of PE, Polyethylene terephthalate (PET) or Polyethylene terephthalate glycol (PETG), EVOH and polyamide (PA) including recycled multilayer film containing some or all of the components. The G51 (see below) samples were prepared in two steps. At first, the polyolefins were mixed under the same conditions mentioned above with the BHE. Then, the new compound was dried mixed and then extruded at 270 °C at 200 RPM with the G51 mixture.

Several Mixed polyolefins were used:

A. 50:50 (wt:wt) of polypropylene (SW75, Carmel Olefins, Israel) and a recycled multi-layer film G51 (a mix of polyethylene, poly(ethylene terephthalate), nylon 6).

B. 50:50 (wt:wt) of recycled polypropylene (Moprylene PP Z1CCPHHM grey 939, Morssinkhof-Rymoplast) and a recycled multi-layer film G51 (a mix of polyethylene, poly(ethylene terephthalate), nylon 6).

In all cases the notched impact resistance increased by 50% with only 5wt% BHE.

EXAMPLE 5: Compatibilization of multipolymer blends

The BHE composition as in Example 1 was used to compatibilize blends of PE, PP, PET or PETG, EVOH and polyamide (PA) including recycled multilayer film containing some or all of the components. The notched impact resistance increased by 40% and the unnotched impact resistance exhibited non-break (NB) attributes with only 5wt% BHE. Other mechanical properties (tensile strength, modulus) were unaffected. The flow of the compositions remained high, with typical MFI values of 15 (230°C/2.16 kg).

EXAMPLE 6: β-Hydroxy Ester (BHE) composition as a tie layer

A tie layer consisting of a BHE composition is prepared according to Example 1 is extruded through a co-extrusion type extruder, through a three-way or else feedblock or multi-manifold die and finally through a coextrusion die. The melt temperature of the tie layer is about 190 °C to about 230 °C. Simultaneously, two incompatible polymers are also coextruded on either side of the tie layer. The incompatible polymer pairs or multilayered multiples are any of the polymers usually found in a multilayer film or sheet, including polyethylene or polypropylene, PET, EVOH, nylon, styrene, acrylic, their copolymers or grafted versions. A resulting three-layer or multiple-layer laminate is produced.

The BHE tie layer may replace any of the materials presently used as tie layers, including polyurethane, EVOH, functionalized polymers such as maleic anhydride- grafted PE or PP, grafting with other functionalities (glycidyl, acrylic, vinyl, etc.), fluorinated polymers, etc.

EXAMPLE 7: Laminate recycling

The laminate prepared according to Example 6 is recycled by available separation processes, where the tie layer being heat processable can be melted down and the adjacent layers on each side of the tie layer peeled off and sorted out. A very thin tie layer will allow for recycling of each adjacent layer, where the thermoplastic nature of the tie layer at the processing temperatures will cause the BHE material to dilute in the stream of the recycled polymer without affecting its properties. This process is preferred to any solventbased process, or any process involving a thermoset tie layer. The resulting multilayer film or sheet is fully-processable, without the risk of micro-gel formation (as in the case of a thermoset tie layer) and the choice of polymers and processing temperatures can be adjusted for ease of separation.

Claims

CLAIMS:

1. A vitrimer comprising at least two polyolefin backbones, at least one of the at least two polyolefin backbones being connected, at least once, with one other polyolefin backbone of the at least two polyolefin backbones, said connection being via a diester containing bridge.

2. The vitrimer of claim 1, wherein said connection is via a diester containing bridge having a general formula (I)

-L-C(OH)-CH₂-O-C(O)-X-C(O)-O-CH₂-C(OH)-L'- (I) wherein X represents a valence bond or a chemical moiety; wherein L and L', are independently a valence bond or a chemical linker to said polyolefin backbone; and wherein said at least two polyolefin backbones may be the same or different within said vitrimer.

3. The vitrimer of claim 1, wherein said X is an organic moiety.

4. The vitrimer of claim 2 or 3, wherein said X is an organic moiety comprising any one or combination of an aliphatic chain, an aliphatic ring and an aromatic ring, the chain or ring optionally including a heteroatom.

5. The vitrimer of claim 4, wherein said X comprises an aromatic ring.

6. The vitrimer of claim 5, wherein said aromatic ring is a phenyl ring.

7. The vitrimer of claim 2, wherein said X is a valence bond.

8. The vitrimer of any one of claims 2 to 7, wherein said L and said L' are identical.

9. The vitrimer of any one of claims 2 to 7, wherein said L and said L' are different.

10. The vitrimer of any one of claims 2 to 9, wherein at least one of said L and L' comprise or is a carbonyl group.

11. The vitrimer of any one of claims 2 to 10, wherein at least one of said L and L' comprises an aliphatic chain, an aliphatic ring and an aromatic ring, and any combinations of same, the chain or ring optionally including a heteroatom.

12. The vitrimer of any one of claims 2 to 11, wherein said L or L' comprise, independently an acrylate moiety.

13. The vitrimer of claim 12, wherein said acrylate moiety is selected from the group consisting of alkyl acrylate, alkyl methacrylate, acrylic acid, methacrylic acid.

14. The vitrimer of claim 1 or 2, wherein said chemical bridge has the general formula (II):

15. The vitrimer of any one of claims 1 to 14, wherein said at least two polyolefin backbones are identical polyolefins.

16. The vitrimer of any one of claims 1 to 14, wherein said at least two polyolefin backbones are different polyolefins.

17. The vitrimer of any one of claims 1 to 16, comprising at least two polyolefin backbones that are cross linked one with another.

18. The vitrimer of any one of claims 1 to 17, comprising a plurality of polyolefin backbones being cross-linked one to another through a plurality of said chemical bridges.

19. The vitrimer of claim 17 or 18, having a degree of crosslinking of at least 0.1% mole.

20. The vitrimer of any one of claims 1 to 19, wherein said at least two polyolefin backbones are independently selected from the group consisting of polyethylene, polypropylene, polymethylpentene, ethyl ene-octene copolymer, and propyl ene-butane copolymer.

21. The vitrimer of any one of claims 1 to 20, having a viscosity within a range of 10² to 10⁶ Pa sec at 1 Hz/sec'¹, and 10¹ to 10⁴ Pa sec at 100 Hz/sec'¹.

22. A masterbatch (MB) composition comprising a polymeric carrier and a vitrimer of any one of claims 1 to 21.

23. The MB composition of claim 22, wherein said polymeric carrier has a first viscosity and said vitrimer has a second viscosity, and wherein the first viscosity is lower than said second viscosity.

24. The MB composition of claim 22 or 23, having a weight ratio between said polymeric carrier and said vitrimer of between about 99: 1 and 50:50.

25. The MB composition of any one of claims 22 to 24, wherein said polymeric carrier comprises a polyolefin.

26. The MB composition of claim 25, wherein said polymeric carrier comprises at least one polyolefin or polyolefin backbone.

27. The MB composition of claim 26, wherein said polyolefin or polyolefin backbone is a polymer or copolymer comprising any one of polyethylene (PE), polypropylene (PP), polyvinyl, polyvinyl alcohol, polyvinyl pyridine, polyolefin styrene.

28. The MB composition of any one of claims 22 to 27, wherein said polymeric carrier comprises a polyolefin that is identical to a polyolefin of the at least two polyolefin backbones in said vitrimer.

29. The MB composition of any one of claims 22 to 28, wherein said polymeric carrier comprises a combination of polymers, at least one being other than a polyolefin.

30. The MB composition of any one of claims 22 to 29, wherein said MB composition comprises trace amount of a catalyst.

31. The MB composition of claim 30, wherein said catalyst is or comprises an element selected from the group consisting of Zn, Sn and Co.

32. A method for obtaining a vitrimer, the method comprises reacting in a reaction mixture an epoxy containing molecule with an anhydride containing molecule, at least one of said epoxy containing molecule and said anhydride containing molecule is grafted on a polyolefin backbone, said reaction forms a diester containing bridge between one polyolefin backbone and one other polyolefin backbone.

33. The method of claim 32, wherein said one polyolefin backbone and said one other polyolefin backbone may be the same or different.

34. The method of claim 33, wherein said epoxy containing molecule is grafted onto the polyolefin backbone.

35. The method of claim 33 or 34, wherein said anhydride containing molecule is grafted onto the polyolefin backbone.

36. The method of any one of claims 32 to 35, wherein said epoxy containing molecule is grafted onto a first polyolefin backbone and said anhydride containing molecule is grafted onto a second polyolefin backbone.

37. The method of claim 36, wherein said first polyolefin backbone and said second polyolefin backbone are the same or different.

38. The method of any one of claims 32 to 37, wherein said epoxy containing molecule is grafted on the polyolefin backbone with a grafting efficiency of between about 0.5% and about 5%.

39. The method of any one of claims 32 to 38, wherein said anhydride containing molecule is grafted on the polyolefin backbone with a grafting efficiency of between about 0.5% and about 5%.

40. The method of any one of claims 32 to 39, wherein said reaction mixture comprises a polymeric carrier.

41. The method of 40, wherein said polymeric carrier is in amount of between about 90wt% and about 97wt% out of a total weight of said reaction mixture.

42. The method of any one of claims 32 to 41, wherein said reaction mixture comprises a catalyst.

43. The method of claim 42, wherein said catalyst is selected from the group consisting of zinc acetate, cobalt acetate, cobalt phthalocyanine, zinc phthalocyanine, tin octoate and other salts and complexes of zinc, tin or cobalt.

44. The method of any one of claims 32 to 43, comprising subjecting the reaction mixture to high-shear mixing.

45. The method of claim 44, wherein said high shear mixing is selected from extrusion and injection molding.

46. The method of any one of claims 32 to 45, wherein said epoxy containing molecule comprise a moiety selected from the group consisting of glycidyl monomethacrylate, glycidyl dimethacrylate, glycidyl methacrylate, allyl glycidyl ether, and t-Butyl glycidyl ether.

47. The method of claim 46, wherein said epoxy containing molecule comprises glycidyl methacrylate.

48. The method of claim 46, wherein said epoxy containing molecule is PE -grafted glycidyl methacrylate.

49. The method of any one of claims 32 to 48, wherein said anhydride containing molecule comprises a moiety selected from the group consisting of phthalic anhydride, maleic anhydride, succinic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, dodecenylsuccinic anhydride, 4-methylethynyl phthalic anhydride and combinations thereof.

50. The method of claim 49, wherein said anhydride moiety is phthalic anhydride.

51. The method of any one of claims 32 to 50, wherein said first polyolefin backbone and said second polyolefin backbone are independently selected from the group consisting of polyethylene, polypropylene, polymethylpentene, ethylene-octene copolymer, and propylene-butane copolymer.

52. A method of polymer compatibilization, the method comprising: providing a polymeric mixture comprising at least two incompatible synthetic polymers and a compatibilization agent, and; subjecting said polymeric mixture to mixing under shear forces; wherein said compatibilization agent comprises at least one of

(a) a vitrimer according to any one of claims 1 to 21 or a MB according to any one of claims 22 to 31; and

(b) a reaction mixture comprising an epoxy containing molecule and an anhydride containing molecule, at least one of said epoxy containing molecule and said anhydride containing molecule is grafted on a polyolefin backbone.

53. The method of claim 52, wherein said reaction mixture is as defined in any one of claims 32 to 51.

54. The method of claim 52 or 53, wherein said at least two incompatible polymers comprises at least one recycled synthetic polymer.

55. The method of any one of claims 52 to 54, wherein said at least two incompatible polymers comprises heterogenous plastic waste.

56. The method of any one of claims 52 to 55, wherein said at least two incompatible polymers comprises at least one polyolefin and at least one nonpolyolefin.

57. The method of claim 56, wherein said at least one non-polyolefin is selected from the group consisting of Polyethylene terephthalate (PET), Polyvinyl chloride (PVC), Polystyrene (PS), Polyethylene oxide (PEO), Polyurethane (PU), Polycarbonate (PC), Polyethylene glycol (PEG), Poly(methyl methacrylate) (PMMA), Polyvinylidene fluoride (PVDF), Polyamide (PA/Nylon), Polyimide (PI), Polyethylene naphthalate (PEN), Polybutadiene (PBD), Polyphenylene oxide (PPO), Polysulfone (PSU), Polyethylene terephthalate glycol (PETG), Polyetheretherketone (PEEK), Polyacrylonitrile (PAN), Polyvinyl acetate (PVAc), Polyvinyl alcohol (PVA), Polyvinyl butyral (PVB), Polypropylene carbonate (PPC), Polylactic acid (PLA), Polyoxymethylene (POM), Polyisoprene (IR), Polyvinyl pyrrolidone (PVP), Polydimethylsiloxane (PDMS), Polyvinyl fluoride (PVF), Polyoxyethylene (POE), Polyoxypropylene (POP), Polyoxymethylene copolymer (POMC), Polymethylpentene (PMP), Polyvinyl carbazole (PVK), Polyvinylidene chloride (PVDC), Polyisobutylene (PIB), Polytetrafluoroethylene (PTFE), Polyetherimide (PEI), Polypropylene oxide (PPOx), Polypropylene sulfide (PPS), Polyvinylpyridine (PVPy), Polyetheresterketone (PEEK), Polyethylene succinate (PES), Polyethylene isophthalate (PEI), Polypropylene fumarate (PPF), Polyethylene terephthalate isophthalate (PETI), Polycaprolactone (PCL), Polyvinylsulfonic acid (PVSA), Polyvinyl butyrate (PVB), Polyphenylene sulfide (PPS), Polyoxybutylene (POB), Polyvinyl formal (PVF), Polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE), Polyvinylpyrrolidone-vinyl acetate copolymer (PVP-VA), Polyester, Ethylene Vinyl Alcohol (EVOH), Polyacrylate (PA), Polycarbonate (PC), Polystyrene (PS), and Polyurethane (PU).

58. A homogenous polymeric blend comprising at least two synthetic polymers and a vitrimer according to any one of claims 1 to 21, wherein, said at least two synthetic polymers are incompatible one with the other in the absence of said vitrimer.

59. The homogenous polymeric blend of claim 58, having at least one of the following characteristics: it has a melt flow index (MFI) value of at least 10 (230°C/2.16 kg); and a sample of said polymeric blend that has been subjected to injection molding has as at least one of: a notched Izod impact resistance of at least 50 J/m;

- tensile strength of at least 20 MPa; and flexural modulus of at least 800 MPa.

60. An article of manufacture comprising the vitrimer according to any one of claims 1 to 21 or the homogenous polymeric blend of claim 55 or 59.

61. The article of manufacture according to claim 60, comprising a multilayer structure having a first component of a first polymeric material and a second component of a second polymeric material, and a compatibilizer interposed between said first component and said second component, wherein said first polymeric component and said second polymeric component are incompatible one with each other, and said compatibilizer is a vitrimer according to any one of claims 1 to 21.