MXPA97007267A - Procedure of polymerization of multiple fa - Google Patents

Abstract

The present invention relates to: providing a multi-phase polymerization process for making a water-insoluble polymer, the method includes, providing a mixture comprising carbon dioxide and an aqueous phase, and containing a monomer and a polymerization initiator, and, polymerize the monomer in the reaction mixture, the monomer can be a hydrocarbon or fluorinated monomer, the polymerization initiator can be soluble in the aqueous phase, soluble in carbon dioxide or insoluble in both the aqueous phase and the dioxide carbon, for the initiator to form a separate phase, the present invention also provides reaction mixtures for the polymerization of multiple phases, useful in the process of making insoluble polymers in ag

Description

MULTI-PHOSES POLYMERIZATION PROCEDURE FIELD OF THE INVENTION The present invention relates to a multi-phase polymerization process for making polymers in the presence of carbon dioxide.

BACKGROUND OF THE INVENTION Polymerization procedures can generally be classified into two basic types: homogeneous and heterogeneous procedures. This classification is usually based on whether the initial reaction mixture or the final reaction mixture or both are homogeneous or heterogeneous. Some polymerization systems that start as homogeneous can become heterogeneous when the polymerization reaction proceeds, due to the insolubility of the resulting polymer in the polymerization medium. Heterogeneous polymerizations are widely used as a means to control viscosity and thermal problems associated with mass and solution polymerizations. Emulsion polymerization is a heterogeneous polymerization process used by the industry to polymerize a variety of monomers. The use of a water or water-rich phase in emulsion polymerizations is common. Polymers commonly formed by emulsion polymerization include acrylics, styrenics, polyvinyl chloride, styrene-butadiene rubber, ethylene-propylene-diene terpolymer, polystyrene, acrylonitrile-butadiene-styrene copolymers, neoprene rubber, acetate copolymers, ethylene vinyl, polymers of styrene-rnaleic anhydride, poly (tetrafluoroethylene), tet afoloroethylene copolymers, polyvinyl fluoride and the like. Recently, heterogeneous polymerizations employing a carbon dioxide phase have been proposed. Carbon dioxide is a desirable medium for polymerization because it is inexpensive and safe for the environment. The patent of E.U.A. No. 5,312,882 to DeSimone et al., Proposes a heterogeneous polymerization process for the synthesis in carbon dioxide of water-insoluble polymers. The heterogeneous reaction mixture includes carbon dioxide, monomer and surfactant. The heterogeneous reaction described does not include a water or water-rich phase. The patent of E.U.O. No. 4,993,404 to Beckman et al., Proposes a microemulsion polymerization system that includes a low polarity fluid, which is a gas at normal temperature and a second phase of water. The monomer is soluble in the water phase and is polymerized in the nuclei to produce a water-soluble polymer. Carbon dioxide has also been used in polymerization systems for the polymerization of hydrocarbon and fluorinated monomers. For example, the patent of E.U.A. No. 3,522,228 to Fukui et al., Proposes the polymerization of vinyl monomers using hydrocarbon polymerization initiators in carbon dioxide. The patent of E.U.A. No. 4,861,845 to Slocum et al., Describes a gas phase polymerization of tetrafluoroethylene and other fluoromonomers diluted with gaseous carbon dioxide. PCT publication No. UO 93/20116 to the University of North Carolina at Chapel Hill discloses methods for making fluoropolymers that include the solubilization of a fluoromonomer in a solvent comprising carbon dioxide. The fluoromonomers are selected from the group consisting of fluoroacrylate onornero, fluoroolefin monomers, fluorostyrene monomers, fluorinated vinyl ether monomers and fluoroalkylene oxide monorials. A need still remains in the art for a method for making polymers that avoids the use of costly or environmentally objectionable solvents, and which are relatively and easily separable from the polymer produced. In addition, it would be desirable to provide polymerization processes, particularly for the polymerization of fluorinated monomers, which are capable of commercialization in conventional polymerization equipment.

BRIEF DESCRIPTION OF THE INVENTION As a first aspect, the present invention provides a multi-phase polymerization process for making water insoluble polymers. The method includes (1) providing a reaction mixture comprising carbon dioxide and an aqueous phase, and containing a monomer and a polymerization initiator, and (2) polimerizing the rnonomer. The monomer is generally soluble in carbon dioxide. The polymerization process is useful for the polymerization of hydrocarbon monomers and fluorinated monomers. The polymerization initiator can be soluble in the aqueous phase, soluble in carbon dioxide or insoluble in both the aqueous phase and carbon dioxide, so that the initiator forms a separate phase, with or without a surfactant. As a second aspect, the present invention provides a multi-phase mixture including carbon dioxide and an aqueous phase and containing a monomer and? N polymerization initiator, with or without a surfactant. As a third aspect, the present invention provides a multi-phase polymerization process for making water insoluble polymers, which includes the steps of providing a reaction mixture including carbon dioxide and an aqueous phase, and a water insoluble polymer; and separating the polymer from the reaction mixture, with or without a surfactant. As a fourth aspect, the present invention provides a multi-phase mixture produced from the polymerization of multiple phases of a monomer. The reaction mixture includes carbon dioxide and an aqueous phase, and a water insoluble polymer, with or without a gas. These and other aspects of the present invention are explained in detail in the following detailed description.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "supercritical" has its conventional meaning in the art. A supercritical fluid (SCF) is a substance that is above its critical temperature and critical pressure (or "critical point"). Compressing a gas usually causes a phase separation and the appearance of a separate liquid phase. However, if the fluid is in a supercritical state, compression will only result in the increase in density: a liquid phase will not form. The use of supercritical fluids to carry out polymerization procedures has received relatively little attention. The term "fluoropolymer" as used herein, has its conventional meaning in the art. See generally Fluoropolymers (L. Wall, Ed. 1972) (Uiley-Interscience Division of John Uliley &Sons); see also Fl? orine-Containi ng Polymers, 7 Encyclopedia of Polymer Science end Engineering 256 (H. Mark et al., Eds., 2d Ed. 1985). Likewise, the term "fluoromonomer" or "fluorinated monomer" refers to fluorinated precursor monomers used in the synthesis of fluoropolymers. The processes of the present invention are carried out in a mixture comprising a carbon dioxide phase and an aqueous phase. The carbon dioxide phase can be in a gaseous, liquid or supercritical state. As will be appreciated by those skilled in the art, all gases have a critical temperature at which the gas can no longer be liquefied by increasing the pressure, and a critical pressure, or pressure that is necessary to liquify the gas at the temperature review. For example, carbon dioxide in its supercritical state exists as a form of matter in which its liquid and gaseous states are indistinguishable from one another. For carbon dioxide, the critical temperature is about 31 ° C and its critical pressure is more than 75.22 kg / cm2. The liquid carbon dioxide can be obtained at temperatures of from about 31 ° C to about -55 ° C. The aqueous phase of the mixture typically comprises water, but may include other additives such as acids, bases, salts, pH regulators, alcohols and the like. Suitable additives are known to those skilled in the art.The ratio of carbon dioxide to aqueous phase in the reaction mixture will depend on the monomer (s) to be polymerized, as well as on the reaction conditions. Generally, the ratio of carbon dioxide to aqueous phase in the reaction mixture will be between about 1:99 and about 99: 1 parts by volume. The mixture may also include one or more cosolvents. Suitable co-solvents will not cause excessive chain transfer. The co-solvents that may be employed in the methods of the present invention include but are not limited to hydrocarbons of C2-Css, alcohols Ci-Css, methylene chloride, toluene, cyclohexane, methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran , perfluorocarbons, hydrofluorocarbons, perfluoroalkyl ethers and the like. Monomers useful in the methods of the present invention include any suitable monomer known to those skilled in the art which is capable of producing a water insoluble polymer. The processes of the present invention are particularly suitable for the polymerization of hydrocarbon and fluorinated monomers. The monomers may be in a liquid or gaseous state. Generally, monomers useful in the methods of the present invention are capable of free radical polymerization. The hydrocarbon monomors which are useful in the processes of the present invention include any suitable hydrocarbon monomer known to those skilled in the art, which is capable of producing water insoluble polymers. Specific examples of suitable hydrocarbon monomers include, but are not limited to, vinyl monomers such as vinyl chloride and vinyl acetate; ethylene; propylene; acrylonitrile; dienes such as isoprene, chloroprene and butadiene; styrenics such as styrene and t-butyl styrene; acrylic monomers such as alkyl methacrylates, alkyl acrylates, ethacrylic acid and acrylic acid; acrylamides; maleic anhydride; and vinyl ether monomers. Preferred fluorinated monomers which are useful in the processes of the present invention will contain at least one fluorine atom, perfluoroalkyl group or perfluoroalkoxy group directly attached to the vinyl group which is subjected to the polymerization. Examples of suitable fluorinated monomers include, but are not limited to, perfluoroolefins, particularly tetrafluoroethylene, perfluoroalquilvinílicos ethers with perfluoroalkyl groups containing 1 to 6 carbon atoms and those functional groups such as CF2 = CF0CF2CF (CF3) 0CF2CF2S02F and CF2 = CF0CF2CF ( CF3) OCF2CF2CO2CH3, hexafluoropropylene, perfluoro (2/2-dimetildioxol) monomers cure site such as bromotrifluoroethylene and partially fluorinated monomers, particularly vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene and perfluoroalkyl with prefluoroalquilo groups containing 1 to 6 atoms of carbon. Preferred fluoromonomers include tetrafluoroethylene, hexafluoropropylene, perfluorometilvinílico ether, perfluoroetilvinílico ether, perfluoropropilvinílico ether, vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene and prefluoro (2,2-dimetildioxol). The polymers produced according to the methods of the present invention include homopolymers of any of the above monomers, or in the embodiment in which two or more coronomers are employed, the polymers can be copolymers. Homopolymers copies that can be produced according to the methods of the present invention include but are not limited to, polyethylene, polyvinyl chloride, polymethyl methacrylate, polystyrene, polychlorotrifluoroethylene, politetrafuoroetileño, polyvinyl fluoride, polyvinylidene fluoride and the like. The polymerization process of the present invention can be carried out with coronomers. The comonomers can be any of the hydrocarbon or fluorinated monomers described above, which are capable of copolymerization. Any combination of copolymerizable monomers can be employed to produce a water insoluble polymer, including hydrocarbon monomers and copolymerizable fluorinated monomers.

Copolymers that can be produced according to the methods of the present invention include but are not limited to tetrafluoroethylene / hexafluoropropylene, tetrafluoroethylene / hex f.Iuorpropylene / vinylidene fluoride, hexafluoropropylene / vinylidenefluoride, perfl? Oroymethylvinyl ether) / fluoride vinylidene, ether per luoro (methyl inyl) / vinylidene fluoride / tetrafluoroethylene, chlorotrifluoroethylene / vinylidene fluoride, chlorotrifluoroethylene / ethylene, chlorotrifl? oroelene / tetra-fluoroethylene / ethylene, tetrafluoroethylene / ether p € > rfluoro (propyl vinyl), tetra luoroethylene / perfluoroimethyl vinyl ether), tetrafluoroethylene / perfluoro (2,2-dimethyl-l, 3-dioxol), tetra-fluoroethylene / ethylene, tetrafl? oroethylene / propylene, tetra luoroethylene / CF2 = CF0CF- 2CF (CF3) OCF2CF2 SO2 F, tetraf1uoroethylene / CF2 = CF0CF2CF2 SO2F, tetraf1uoroethylene / hexa-fluoropropylene / perfluoro (propylvinyl) ether, styrene / butadiene, styrene / chloroprene, styrene / acyl nitrile, acrylonitrile / butadiene, ethylene / vinyl acetate, chloroprene / methyl methacrylate, and chloroprene / acrylonitrile. The initiator used in the methods of the present invention can be soluble in the aqueous phase or insoluble in the aqueous phase. The initiators which are insoluble in the aqueous phase can be soluble in carbon dioxide or insoluble in both the aqueous phase and in carbon dioxide, so that the initiator forms a separate phase. Examples of suitable initiators that are insoluble in the aqueous phase include but are not limited to halogenated initiators and other free radical hydrocarbon initiators. Suitable halogenated initiators include, for example, chlorinated and fluorinated initiators. For example, suitable halogenated polymerization initiators include chlorocarbon and fluorocarbon-based acyl peroxides such as trichloroacetyl peroxide, bis (perf-2-propoxypropionyl) peroxide, CCF3CF2CF20 FICF3) C00J "2, perfluoropropionyl peroxides, (CF3) CF2 CF2 C00) _, (CF3CF2C00) 2, { CF3CF2CF2) CCF (CF3) CF201nCF (CF3) C00.}. D CCICF2 (CF2) n C00] 2, and CHCF2 (CF2) nC00] 2, where n = 0-8; azo perfluoroalkyl compounds such as perfluoroazoisopropane, C (CF 3) 2 CF = 32; R "N = NR", wherein R "is a linear or branched perfluorocarbon group having 1-8 carbons; stable or hindered per fluoro radicals such as a hexafluoropropylene trimer radical, radical of E (CF-3) 2CF 1_ (CF2CF3) C- and perfluoroalkanes. Preferred halogenated initiators include trichloroacetyl peroxide, bis (perfl? Oro-2-ropoxy) propionyl peroxide, perfluoropropionyl peroxide, perfluoroazoisopropane and hexafluoropropylene trimer radical. Examples of hydrocarbon free radical initiators include but are not limited to acetylcyclohexanesulfonyl peroxide, dicetyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate. t-butyl perneodecanoate, 2,2'-azobis (methoxy-2,4-dimethylvaleronitrile), t-butyl perpivalate, dioxtanoyl peroxide, dilauroyl peroxide, 2,2'-azobis (2,4-dimethylvaleronitrile), t-butylazo-2-cyanobutane, dibenzoyl peroxide, t-butyl per-2-ethylhexanoate, t-butyl perrnaleate, 2,2'-azobis (isobutyronitrile), bis (t-butyl butylcyclohexane, t-butyl peroxyisopropylcarbonate, t-butyl peracetate, 2,2'- bis (t-butylperoxy) butane, dicumyl peroxide, di-t-amyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, pinano hydroperoxide, eumeno hydroperoxide and t-butyl hydroperoxide. Preferred hydrocarbon free radicals include azobisisob? tironitrile ("AIBN"), dilauroyl peroxide, diisopropyl peroxydicarbamate, t-butyl hydroperoxide, di-t-butyl peroxide, and dicumyl peroxide.The initiators which are soluble in the aqueous include but are not limited to inorganic peroxides such as hydrogen peroxide or hydrogen ion. ersulfate; potassium permanganate; disuccinic acid peroxide and redox initiators such as alkali metal persulfates and bisulfates, ammonium persulfates, ferrous fats only, silver nitrate and cupric sulfate or any combinations thereof. The initiator can be added in pure form or conveniently added as a solution in a co-solvent. Typically, the initiator is used in a quantity conventionally employed for polymerization. For example, the initiator can be used in an amount of about 10-6 to 10, preferably about 10-s to 2, parts by weight per 100 parts by weight of monomer. The methods of the present invention may also include a surfactant. Any surfactant known to those skilled in the art may be employed. Typical surfactants include anionic surfactants, cationic surfactants, zwitterionic surfactants, block copolymer and nonionic graft surfactants, and surfactants and polymeric stabilizers. For example, suitable polymeric stabilizers include, but are not limited to, polyvinyl alcohol, hydroxypropylcellulose, sodium styrene-fonate, polyethylene oxide, and the sodium salt of polyacrylic acid. Examples of useful anionic surfactants include but are not limited to fatty acid soaps such as sodium or potassium stearate, laurate and palmitate, sulphonates, sulfates and fluorinated surfactants such as perfluorooctane-octanoic acid and salts thereof, including salts thereof. sodium and ammonium salts thereof. Examples of useful nonionic surfactants include surfactants of the pluronic family, family SPANMR O family TUEENMR and polypropylene oxide or polyethylene g-oxide. Examples of useful cationic surfactants include but are not limited to dodecylammonium chloride and acetyltrimethylammonium bromide. In addition, silicon and fluorocarbon surfactants are also useful. Examples include but are not limited to poly (1,1-dihydroperfluorooct.il acrylate) and graft, block and random copolymers thereof, poly (1,1,2, -tetrahydroperfluoroacrylates and methacrylates) and graft copolymers, of block and random thereof, polysiloxanes and block copolymers and graft copolymers thereof, particularly those with hydrophilic ethylene oxide segments. The methods of the present invention may include optional other agents capable of modifying, regulating or controlling the physical or chemical properties of the resulting polymer. For example, one skilled in the art will appreciate that a chain transfer agent can be employed to regulate the molecular weight of the resulting polymer, thereby controlling the physical and chemical properties thereof. Chain transfer agents that can be optionally employed in the methods of the present invention include but are not limited to alcohols such as methanol, mercaptans such as ethyl and butyl mercaptan, sulfides such as butyl sulfide, halogen-containing species such as alkylhalides such as alkyl iodides, perfluoroalkyl iodides, alkyl bromides, perfluoroacyl bromides, carbon tetrachloride and chloroform, and alkanes such as ethane and methylcyclohexane. It may also be desirable to include compounds that accelerate the decomposition of the initiator. Such compounds typically ermit the polymerization reaction to take place at lower pressures than would otherwise be required, thereby allowing the methods of the present invention to be practiced in conventional fluoropolymerization reactors. Suitable compounds that accelerate decomposition are known to those skilled in the art and include, but are not limited to, redox systems, sulfur dioxide, ultraviolet light, and the like. The polymerization reaction can be carried out at a temperature from about -50 ° C to about 200 ° C and is typically carried out at a temperature between about -20 ° C and about 150 ° C. Suitable antifreeze agents such as ethylene glycol can be added to the aqueous phase of the reaction mixture, to prevent freezing of the aqueous phase during reactions carried out at temperatures below the freezing point of the aqueous phase. The reaction can be carried out at a pressure ranging from about 1.05 to about 3.163 kg / cm2, and is typically carried out at a pressure between about 35.15 kg / cm2 and about 703 kg / cm2. The polymerization can be carried out intermittently or continuously with careful mixing of the reagents in any suitably designed high pressure reaction vessel, or tubular reaction vessel. To remove the heat involved during the polymerization, the pressure apparatus advantageously includes a cooling system. Additional features of the pressure apparatus used in accordance with the invention include heating means such as an electric heating oven for heating the reaction mixture to the desired temperature and mixing means, i.e. agitators such as paddle stirrers, stirrers of motor or multistage counter-current pulse agitators, blades and the like. The polymerization can be carried out, for example, by placing the monomer and initiator in the pressure apparatus and introducing carbon dioxide and the aqueous phase. The reaction vessel is closed and the reaction mixture is brought to the polymerization temperature and pressure. Alternatively, only a part of the reaction mixture can be introduced into an autoclave and heated to the polymerization pressure and temperature, by pumping additional reaction mixture at a rate corresponding to the speed of the polymerization. In another possible process, some of the monomers are initially taken to the autoclave in the total amount of carbon dioxide and the monomers or comonomers are pumped into the autoclave together with the initiator at the rate at which the polymerization proceeds. When the polymerization is complete the polymer can be separated from the reaction mixture. Any suitable means for separating the polymer from the carbon dioxide and the aqueous phase can be used. Typically, according to the process of the present invention, the polymer is separated from the reaction mixture by venting carbon dioxide to the atmosphere. Subsequently the polymer can be collected simply by physical isolation. The polymers produced according to the methods of the present invention are useful as thermoplastics and elastomers which are useful for the manufacture of adhesives and molded articles such as valves, bottles, films, fibers, resins and dies. Fluoropolymers in particular have applications in areas where conventional fluoropolymers are employed, and particularly as coatings for cables, gaskets, seals, hoses, container linings, elastomers, molded resins, protective coatings and the like. The following examples are provided to illustrate the present invention and should not be considered as limiting thereof. In these examples, Kg means kilograms, g means grams, mg means milligrams, L means liters, mL means milliliters, 3 means Joules, J / g means Joules per gram, mole means mole (s), Kg / mol means kilograms per mole , rpm means revolution. per minute, TFE means tetrafluoroethylene, CO2 means carbon dioxide, K2B2? ß means potassium persulfate, DSC stands for differential scanning calorimetry and ° C means centigrade grams. Molecular weight is estimated using the method described in T. Suwa, et al., J. Applied Polymer Sci. 17: 3253 (1973).

EXAMPLE 1 ml of K2B2O8, 10 ml of water and 25 mg of perfluorooctanoic acid are added to a 25 ml stainless steel reaction vessel equipped with a horizontal paddle stirrer. The cell is cooled to well below 0 ° C and 10 g of a 50:50 mixture of TFE: C 2 2 (5 g of TFE and 5 g of CO2) are condensed under pressure. The reactor is gradually heated to 50 ° C. Stirring starts as soon as the ice in the cell melts allowing the agitator to spin freely. The stirring is maintained for 24 hours at 50 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 3.6 g of product (yield 72%). The DSC analysis produces a virgin melting point of 329 ° C, a second melting of 330.0 ° C and a crystallization heat of -60.9 J / g (second heating) corresponding to an estimated average molecular weight number of 20 Kg / ol.

EXAMPLE 2 To a 25 mL stainless steel reaction vessel equipped with a horizontal paddle-type stirrer are added 25 rnG of K2S2O8, 10 rnL of water and 25 mg of sodium perfluorooctanoate. The cell is cooled to well below 0 ° C and 10 g of a 50:50 mixture of TFE: CÜ2 (5 g of TFE and 5 g of CO2) are condensed under pressure. The reactor is gradually heated to 50 ° C. Stirring starts as the ice in the cell melts, allowing the agitator to spin freely. The stirring is maintained for 24 hours at 50 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 4.1 g of product (82% yield). The DSC analysis produces a virgin melting point of 330.0 ° C, a second melting of 329 ° C and a crystallization heat of -60.9 J / g (second heating) corresponding to an estimated average molecular weight number of 20 Kg / ol.

EXAMPLE 3 To a 25 mL stainless steel reaction vessel equipped with a horizontal paddle stirrer is added 2.9 mg of K2S2O8 and 10 mL of water. The cell is cooled to well below 0 ° C and 8.2 g of a 50:50 mixture of TFE: C02 (4.1 g of TFE and 4.1 g of CO2) are condensed under pressure. The reactor is gradually heated to 80 ° C. Stirring starts as the ice in the cell melts, allowing the agitator to spin freely. Stirring is maintained for 3 hours at 80 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 2.0 g of product (49% yield). The DSC analysis yields a virgin melting point of 334.7 ° C, a second melting of 333.1 ° C and a heat of crystallization of -50.8 J / g (second heating) corresponding to an estimated average molecular weight number of 60 Kg / ol.

EXAMPLE 4 To a 25 mL stainless steel reaction vessel equipped with a horizontal paddle type stirrer are added 0.29 mg of and 10 L of water. The cell is cooled to well below 0 ° C and 10.5 g of a 50:50 mixture of TFE: C02 (5.2 g of TFE and 5.2 g of CO2) are condensed under pressure. The reactor is gradually heated to 75 ° C. Stirring starts as the ice in the cell melts, allowing the agitator to spin freely. Stirring is maintained for 7 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction yields 0.37 g of product (7.0% yield). The DSC analysis produces a virgin melting point of 337.7 ° C, a second melting of 331.2 ° C and a crystallization heat of -40.6 J / g (second heating) corresponding to an estimated average molecular weight number of 170 Kg / mol EXAMPLE 5 To a 25 rnL stainless steel reaction vessel equipped with a horizontal paddle stirrer is added 0.49 g of K2S2O8 and 10 mL of water. The cell is cooled to well below 0 ° C and 11.5 g of a 50:50 mixture of TFE: C 2 2 (5.7 g of TFE and 5.7 g of CO2) are condensed under pressure. The reactor is gradually heated to 75 ° C. Agitation starts as soon as the ice in the cell melts, allowing the agitator to rotate freely. Stirring is maintained for 17 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 2.5 g of product (43% yield). The DSC analysis produces a virgin firing point of 338.3 ° C, a second melting of 327.7 ° C and a crystallization heat of -37.7 J / g (second heating) which corresponds to an estimated average molecular weight number of 260 Kg / mol.

EXAMPLE 6 To a 25 mL stainless steel reaction vessel equipped with a horizontal paddle stirrer, 0.11 mg of K2S2O8 and 10 L of water are added. The cell is cooled to well below 0 ° C and 11.7 g of a 50:50 mixture of TFE: C02 (5.8 g of TFE and 5.8 g of CO2) are condensed under pressure. The reactor is heated gradually to 75 ° C. Stirring starts as soon as 7"> the ice in the cell melts, allowing the agitator to spin freely. Stirring is maintained for 17 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 0.7 g of product (12% yield). The DSC analysis produces a virgin melting point of 334.9 ° C, a second melting of 327.0 ° C and a crystallization heat of -28.0 J / g (second heating) corresponding to an estimated average molecular weight number of 1,160 kg. / mol.

EXAMPLE 7 A 600 mL stainless steel autoclave equipped with stirring by means of a stirrer is seasoned with a solution of pereulfate in water, heating to ca. 90 ° C and filling with 500 L of an initiator solution (ca. 0.5 g of ammonium persulfate in 500 rnL of water) and then heated for a couple of hours. This procedure is repeated twice before carrying out the polymerization. To the seasoned reactor 0.8 mg of K2S2O8 and 250 mL of water are added. The autoclave is cooled to well below 0 ° C and 53.0 g of a 50:50 mixture of TFE: C02 (26.5 g of TFE and 26.5 g of CO2) is condensed under pressure. The reactor is gradually heated to 75 ° C. Stirring starts at ca. 1000 rpm as soon as the ice in the cell melts, allowing the agitator to spin freely. Stirring is maintained for 5 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 24 g of product (90% yield). The DSC analysis of this product produces a virgin melting point of 338.6 ° C, a second melting of 328.5 ° C and a heat of crystallization of -29.4 J / g (second melting) corresponding to an estimated average molecular weight number of 900 Kg / rnol.

EXAMPLE 8 A 600 L stainless steel autoclave equipped with agitation by means of a stirrer is seasoned with a persulfate solution in water, heating to ca. 90 ° C, then filling with 500 mL of an initiator solution (ca. 0.5 g of ammonium persulfate in 500 rnL of water) and then heating for a couple of hours. This procedure is repeated twice before carrying out the polymerization. To the seasoned reactor 2.6 mg of K2S2O8 and 250 mL of water are added. The autoclave is cooled to well below 0 ° C and 50.1 g of a 50:50 mixture of TFE: C? 2 (25 g of TFE and 25 g of CO2) is condensed under pressure. The reactor is gradually heated to 75 ° C. Stirring starts at ca. 1000 rpm as soon as the ice in the cell melts, allowing the agitator to spin freely. Stirring is maintained for 5 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction yields 22.fi g of product (90% yield). The DSC analysis produces a virgin melting point of 336.7 ° C, a second fusion of 329.4e, C and a crystallization heat of 38.2 J / g (second melt) corresponding to an estimated average molecular weight number of 235 Kg. / rnol.

EXAMPLE 9 A 600 L stainless steel autoclave equipped with agitation by means of a stirrer is seasoned with a persulfate solution in water, heating to ca. 90 ° C, then filling with 500 L of an initiator solution (ca. 0.5 g of ammonium persulfate in 500 mL of water) and then heating for a couple of hours. This procedure is repeated twice before carrying out the polymerization. To the seasoned reactor are added 3.2 mg of K2S2O8, 10 mg of ammonium perfluorooctanoate and 250 mL of water. The autoclave is cooled to well below 0 ° C and 51 g of a 50:50 mixture of TFE: C02 (25.5 g of TFE and 25.5 g of CO2) is condensed under pressure. The reactor is gradually heated to 75 ° C. Stirring starts at ca. 1000 rpm as soon as the ice in the cell melts, allowing the agitator to rotate freely. Stirring is maintained for 5 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction yields 20.9 g of product (82% yield). The DSC analysis produces a virgin melting point of 338.6 ° C, a second melting of 330.3 ° C and a heat of crystallization of 35.3 J / g (second melting) corresponding to an estimated average molecular weight number of 350 Kg / rnol.

EXAMPLE 10 A stainless steel autoclave of 600 rnL equipped with agitation by means of a stirrer is seasoned with a persulfate solution in water, heating to ca. 90 ° C, then filling with 500 L of an initiator solution (ca. 0.5 g of ammonium persulfate in 500 rnL of water) and then heating for a couple of hours. This procedure is repeated twice before carrying out the polymerization. To the seasoned reactor are added 0.8 mg of K2S2O8, 10 mg of ammonium perfluorooctanoate and 250 rnL of water. The autoclave is cooled to well below 0 ° C and 50.9 g of a 50:50 mixture of TFE: C02 (25.4 g of TFE and 25.4 g of CO2) is condensed under pressure. The reactor is gradually heated to 75 ° C. Stirring starts at ca. 1000 rp as the ice in the cell melts, allowing the agitator to spin freely. Stirring is maintained for 5 hours at 75 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction yields 21.7 g of product (85% yield). The DSC analysis produces a virgin fusion point of 344. lßC, a second fusion of 328.5ßC and a crystallization heat of 35.3 J / g (second fusion) corresponding to an estimated average molecular weight number of 350 Kg / mol .

EXAMPLE 11 To a 25 mL stainless steel reaction vessel equipped with a horizontal paddle-type stirrer are added 0.04 L of di (tert-butyl) peroxide, 0.11 mL of methyl cyclohexane (as a chain transfer agent) and 8 rnL of water. The cell is cooled to well below 0 ° C and 6.8 g of a 50:50 mixture of TFE: C 2 2 (3.4 g of TFE and 3.4 g of CO2) are condensed under pressure, followed by an addition of 3.5 g of CO2 - The reactor is heated gradually to 140 ° C. Stirring starts as soon as the ice in the cell melts allowing the agitator to spin freely. Stirring is maintained for 4 hours at 140 ° C before the pressure is vented out of the cell, the cell is opened and the contents are recovered. The reaction produces 1.1 g of low molecular weight polytetrafluoroethylene (37% yield).

EXAMPLE 12 Ethylene is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 7 employing a water-soluble initiator such as ammonium persulfate in the absence of a surfactant. One skilled in the art will appreciate that other initiators and surfactants soluble in water may be employed.

EXAMPLE 13 Vinyl chloride is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 7 employing a water-soluble initiator such as ammonium persulfate in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 14 Methyl methacrylate is polymerized in a mixed medium consisting of water and carbon dioxide using a water-soluble initiator such as ammonium persulphate according to the method of Example 7 in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 15 Styrene is polymerized in a mixed medium consisting of water and carbon dioxide using a water-soluble initiator such as ammonium persulfate according to the method of example 7 in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 16 Ethylene is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of example 11 employing a water soluble initiator such as AIBN in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 17 Vinyl chloride is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 11 employing a water soluble initiator such as AIBN in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 18 Methyl methacrylate is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of example 11 employing a water soluble initiator such as AIBN in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 19 Styrene is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 11 employing a water-soluble initiator such as AIBN in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 20 Ethylene and vinyl acetate are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 11 employing a water-soluble initiator such as AIBN, both in the presence and in the absence of a surface-active agent. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 21 Ethylene and vinyl acetate are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of example 7 employing a water-soluble initiator such as ammonium persulfate, both in the presence and in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 22 Chloroprene is polysorbed in a mixed medium consisting of water and carbon dioxide according to the method of Example 11 employing a water-soluble initiator such as AIBN, both in the presence and absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 23 Chloroprene is polymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 7, employing a water-soluble initiator such as ammonium pereulfate, both in the presence and absence of a surfactant. One skilled in the art will appreciate that other initiators and surfactants soluble in water may be employed.

EXAMPLE 24 Chloroprene and etherane are copolyzed in a mixed medium consisting of water and carbon dioxide according to the method of example 11 employing a water-soluble initiator such as AIBN, both in the presence and in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 25 Chloroprene and styrene are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 7, employing a water-soluble initiator such as ammonium persulfate, both in the presence and absence of a surface-active agent. . One skilled in the art will appreciate that other initiators and surfactants soluble in water may be employed.

EXAMPLE 26 Chloroprene and methyl methacrylate are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of example 11 employing a water-soluble initiator such as AIBN, both in the presence and absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 27 Chloroprene and methyl methacrylate are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 7, employing an acid-soluble initiator such as ammonium persulfate, both in the presence and in the absence of a surfactant. . One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 28 Chloroprene and acrylonitrile are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of example 11 employing a water soluble initiator such as AIBN, both in the presence and in the absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed.

EXAMPLE 29 Chloroprene and acrylonitrile are copolymerized in a mixed medium consisting of water and carbon dioxide according to the method of Example 7, employing a water-soluble initiator such as ammonium persulfate, both in the presence and absence of a surfactant. One skilled in the art will appreciate that other initiators and water soluble surfactants may be employed. The foregoing is illustrative of the present invention and should not be considered as limiting thereof. The invention is defined by the following claims, including equivalents of the claims therein.

Claims (29)

NOVELTY OF THE INVENTION CLAIMS

1. - A multi-phase polymerization process for manufacturing a water-insoluble polymer, said method comprises: providing a polymerization reaction mixture comprising carbon dioxide and an aqueous phase, said mixture containing a monomer and a polymerization initiator capable of initiating the polymerization of said monomer; and polymerizing said monomer in said polymerization reaction mixture to produce said water insoluble polymer.

2. The process according to claim 1, wherein said polymerization initiator is solubilized in said aqueous phase.

3. The process according to claim 1, wherein said polymerization initiator is insoluble in said aqueous phase.

4. The process according to claim 3, wherein said polymerization initiator is solubilized in said carbon dioxide.

5. The process according to claim 3, wherein said polymerization initiator is unsolvable in said aqueous phase and insoluble in said carbon dioxide and forms a separate phase in said polymerization reaction mixture.

6. The process according to claim 1, wherein said monomer is a hydrocarbon monomer.

7. The process according to claim 6, wherein said hydrocarbon monomer is selected from the group consisting of vinyl monomers, diene monomers, styrene monomers, acrylic monomers, acrylate nonomers and vinyl ether monomers .

8. The process according to claim 6, wherein said hydrocarbon monomer is selected from the group consisting of monomers of vinyl chloride, vinyl acetate, ethylene, propylene, acrylonitrile, isonium, chloroprene, butadiene, ethene, t-butyl styrene, alkyl (meth) acrylates, acrylamide, maleic anhydride and vinyl ether.

9. The process according to claim 1, wherein said monomer is a fluorinated monomer.

10. The method according to claim 9, wherein said fl oraned monomer is selected from the group consisting of monomers having at least one fluorine bonded to a vinyl carbon, monomers having at least one group perfluoroalkyl bonded to a vinyl carbon, and monomers having at least one perfluoroalkyl group linked to vinyl carbon.

11. - The process according to claim 9, wherein said fluorinated monomer is selected from the group consisting of perfluoroolefins and perfluoroalkyl ethers.

12. The process according to claim 9, wherein said fluorinated monomer is selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, perfluoromethylvinyl ether, perfluoroethylvinyl ether, perfluoropropylvinyl ether, vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene and perfluoro (2,2-dimethyl dioxol).

13. The process according to claim 2, wherein said polymerization initiator is selected from the group consisting of inorganic peroxide initiators and redox initiators, soluble in said aqueous phase.

14. The process according to claim 3, wherein said polymerization initiator is selected from the group consisting of halogenated initiators and initiators of free hydrocarbon radical, insoluble in said aqueous phase.

15. The process according to claim 1, wherein said carbon dioxide is liquid carbon dioxide.

16. The process according to claim 1, wherein said carbon dioxide is gaseous carbon dioxide.

17. - The method according to claim 1, wherein said carbon dioxide is supercritical carbon dioxide.

18. The method according to claim 1, wherein said process is carried out in the presence of a surfactant.

19. The method according to claim 1, which further comprises the step of separating said polymer from said mixture and collecting said polymer.

20. The method according to claim 19, wherein said step of separating said polymer from said mixture comprises venting said carbon dioxide phase into the atmosphere.

21. The process according to claim 1, wherein said process is carried out in the presence of a chain transfer agent.

22. The process according to claim 1, further comprising adding said comonomer to said reaction mixture, and said polymerization step comprising copolymerizing said monomer with said comonomer.

23. The process according to claim 22, wherein said comonomer is selected from the group consisting of fluorinated and non-fluorinated comonomers.

24. The process according to claim 22, wherein said comonomer is selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, perfluoromethylvinyl ether, perfl? Oroethylvinyl ether, perfluoropropylvinyl ether, vinyl fluoride, vinylidene fluoride, chlorotrifluoroethylene and? erfl? gold (2,2-dimethyl dioxole), vinyl chloride, vinyl acetate, vinyl ether, ethylene, propylene, acrylonitrile, isoprene, chloroprene, butadiene, styrene, t-butyl styrene, acrylate, alkylene (met) acrylate, acrylamide and maleic anhydride.

25. A multi-phase mixture useful for carrying out the multi-phase polymerization process of a monomer, said reaction mixture comprising: carbon dioxide and an aqueous phase; a monomer solubilized in carbon dioxide and a polymerization initiator.

26. The multi-phase mixture according to claim 25, further comprising a surfactant.

27. A multi-phase polymerization process for manufacturing a polymer, said method comprises: providing a reaction mixture comprising carbon dioxide and an aqueous phase and a water-insoluble polymer, and then separating said polymer from said mixture of reaction.

28. A multi-phase mixture produced from the multi-phase polymerization of a monomer, said reaction mixture comprising: carbon dioxide and an aqueous phase; and a water insoluble polymer.

29. A polymer produced by the process according to claim 1.