Vinyl ethers emulsion copolymers

Copolymerization of tetrafluoroethylene and carboxylated perfluorovinyl ether is carried out either in solution, bulk or emulsion system with a radical initiator. A typical copolymer composition curve is given in Figure 1, where Ml or M2 was copolymerized with tetrafluoroethylene in bulk system at 70°C. The monomer reactivity ratios of tetrafluoroethylene and each vinyl ether are calculated as 7.0 and 0.14, respectively. 

Copolymers from tetrafluoroethylene and 40% perfluorovinyl methyl ether are also elastomers (glass-transition temperature — 12°C). The copolymerization is carried out in aqueous emulsion with ammonium perfluoro-octanoate as emulsifier. Vulcanization is possible with hexamethylene diamine via the small amount of perfluoro(4-carboxy methyl butyl vinyl ether) also polymerized into the copolymer. This ether is produced from perfluoroglutaryl fluoride and hexafluoropropylene oxide. 

Besides vinyl acetate monomer, three other components are neeessary to earry out an emulsion polymerization water, an emulsifier and/or a proteetive eolloid, and a water-soluble initiator. Most commonly, anionic long-chain alkyl sulfonates are used as surfactants in amounts up to 6%. Studies have shown that the rate of polymerization is dependent on the amoimt of emulsifier present, with the rates inereasing as the amoimt of emulsifier is increased up to a certain point and then falling olF as free-radieal ehain transfer to the surfaetant beeomes a serious competing side reaetion [240]. In general, surfactants are used in eombination with a protective colloid. Especially useful as protective colloids are poly(vinyl alcohol), hydroxyethyl cellulose, alkyl vinyl ether-maleic anhydride and styrene-allyl alcohol copolymers, and gum arable. Water-soluble initiators, particularly potassium persulfate, alkali peroxydisulfates, hydrogen peroxide, and various redox systems, are most commonly used. 

Vinyl ethers copolymerize with methyl methacrylate to give alternating copolymer units as well as homopolymer segments of methyl methacrylate [35]. With other monomers this is also true, and either solution, emulsion, suspension, or bulk polymerization techniques may be used. The pH should be kept at about 8 or above in aqueous systems to prevent hydrolysis of the vinyl ether. The / 2 (alkyl vinyl ether) values are low and approach zero for bulk polymerization systems [36-38] utilizing such monomers... 

Free-radical copolymerization of alkyl vinyl ethers has been carried out with the following typical monomers acrylic acid (bulk and emulsion) [39,40], acrylonitrile (emulsion) [26,27], acrylic esters (emulsion) [41], methyl methacrylate (bulk) [42], maleic anhydride (solution) [43], vinyl acetate (bulk and emulsion) [27,44,45], and vinyl chloride (emulsion) [26, 37,46]. The properties of these and other copolymers are described in a technical bulletin by General Aniline Film Corporation [38]. 

Adhesives are often based on blends to optimize the key properties of interest, but as they are often designed for specific applications, the blend compositions are rarely disclosed. However, a large number of patents exist related to adhesive compositions. Blends of alky(meth)acrylates and poly(vinyl alkyl ethers) were described for self-adherent (Tg < 10 °C) adhesives or hot melt adhesives for labels, adhesive tapes or films [171]. Hot melt adhesives based on a blend of poly(vinyl alcohol) and copolymers of alkyl(meth)acrylates and other vinylic monomers were described for paper, wood and other cellulosic articles [172]. The PVOH based hot melt adhesives offer the advantage of repulpability for paper/cellulosic products requiring adhesives. A waterborne adhesive for coating friable surfaces (e.g., chalky weathered paint or masonry) was described as comprising a blend of separate emulsion polymers [173]. The examples noted blends of a MMA-nBA-MAA emulsion terpolymers with MMA-nBA emulsion copolymer with the copolymer having a particle size less than 120 nm. 

Epichlorohydrin copolymer mfg., decolorization Epichlorohydrin copolymer mfg., flocculation Epichlorohydrin copolymer mfg., lipsticks Diethylaminoethyl acrylate copolymer, coatings Vinyl isobutyl ether Vinyl methyl ether copolymer, lacquers Vinyl isobutyl ether Vinyl methyl ether copolymer, latex emulsions Polyvinyl chloride copolymerization... 

Water is the ideal solvent from the cost and pollution viewpoints, but it is a non-solvent for many surface coating polymers. It will ssolve a small number of homopolymers, notably those derived from acrylamide, acrylic acid, itaconic acid, vinyl methyl ether, vinyl pyrrolidone and vinyl sulphonic acid, but none of these homopolymers forms flexible films of use in the coatings industry. While copolymers of acrylic or methacrylic acids with acrylate esters are generally insoluble in water, their salts are soluble when the acid content is over 5% (for hydrophilic monomers) and 12% (for hydrophobic monomers). Such polymers can be prepared in solution, or in emulsion, but not in aqueous solution. This is because the acrylate esters are insoluble in water. The acid is copolymerised in the un-ionised form because the ion is unreactive to free radicals. In emulsion polymerisation, care has to be taken to avoid homopolymerisation of the acrylic or methacrylic acid in the water phase. Suppression of homopolymerisation requires a low concentration of acid throughout the polymerisation process. This can be achieved by using a long reaction period and slow addition of monomer mixture, or by careful pH buffer selection. 

Uses Emollient, solvent, emulsion stabilizer for cosmetics, topical pharmaceuticals solubilizer, coupling agent for perfumes, colors, flavors, sunscreen compds. solvent for sprayed org. pesticides plasticizer and stabilizer in vinyl copolymers made from PVAc and PVC defoamer in PVAc emulsions Features Stable base produces sprayable oils which spread well, have good adherence, and are not readily removed by rainfall Properties Yel. cl. liq., mild odor sol. in most org. soivs. such as alcohols, ketones, esters, glycol ethers, veg. oil, min. oil, aliphatic, aromatic, chlorinated hydrocarbons disp. in glycols, triols, polyols m.w. 258 (theorel) sp.gr. 0.905 0.01 dens. 7.45 Ib/gal f.p. 10 C acid no. 5 max. iodine no. 1 max. sapon no. 225-240 flash pt. (OC) 160 C min. pH 7.0 (10% disp.)... 

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