Vinyl homopolymer

Poly(vinyl acetate) emulsions are excellent bases for water-resistant paper adhesives destined for use in manufacturing bags, tubes, and cartons. Glue-lap adhesives, which require moderate-to-high resistance to water, exemplify this type. When routine water resistance is required, a homopolymer vinyl acetate emulsion containing a ceUulosic protective coUoid is effective for most purposes. Next effective are emulsions containing fuUy hydrolyzed poly(vinyl alcohol) as a protective coUoid, foUowed by those containing partiaUy hydrolyzed poly(vinyl acetate). 

Pliovic [Goodyear], TM for homopolymers, vinyl dispersion resin, plastisol, and organosol compounds. 

Synonyms cas 9002-89-5 pva pvoh elvanol ethenol homopolymer vinyl alcohol polymer Polyvinylpyrrolidnone Homopolymer... 

Synonyms Acetic acid, elhenyl ester, homopolymer Acetic acid, vinyl ester, polymer Acetic acid vinyl ester polymers Ethenyl acetate, homopolymer Poly (vinylacetate) Polyvinyl acetate homopolymer Polyvinyl acetate resin PVA PVAc Vinyl acetate homopolymer Vinyl acetate polymer Vinyl acetate resin Classification Homopolymer Definition Homopolymer of vinyl acetate Empirical (C HsOJ,... 

Polyvinylidene chloride appears as a crystalline polymer excelling in chemical resistance and low permeability, but it is difficult to process and thermally unstable. Both homopolymers vinyl acetate and vinyl alcohol ap-... 

Vinyl chloride homopolymer Vinyl chloride polymer Vinyl chloride resin Vinyon Definition Synthetic thermoplastic high polymer in rigid, plasticized, std. and high impact grades resist, to weathering, moisture, most acids, fats, petrol, hydrocarbons, fungus dimensionally stable good dielec, props. 

In Fig. I presents data analysis for alcohol and homopolymer vinyl acetate. As can be seen Ifom the curves of the DTA, for PVA in the range of 150-250°C, there has been an exothermic region, is not accompanied by a noticeable loss of weight. When the temperature 230-310°C is fixed acute endofiiermic peak, which corresponds to the maximum speed of the weight loss at 300°C. 

Homopolymers.—Vinyl Monomers and Derivatives. Robinson et al. have described an exhaustive study of the measurement of poly(vinyl chloride) tacticity by H n.m.r. It was found that different solutions of the same polymer were less reproducible than repeat runs on the same solution i.e. sampling errors were greater than instrumental factors. Overall, one must use several samples for maximum precision, and combine results from both CH and CHj signals. The sensitivity of C resonance frequencies to small structural changes is illustrated by reports of the resolution of configurational pentads in polymers of... 

Uses Emulsifier for vinyl acetate homopolymers, vinyl acetate-dlbutyl maleate copolymers, esp. suitable for highly filled PVAc and PC emulsions food-pkg. adhesives, paper/paperboard... 

DMAC and nonpolar solvents form synergistic mixtures which dissolve high molecular weight vinyl chloride homopolymers. For example, a mixture of DMAC with an equal volume of carbon disulfide [75-15-0] a nonsolvent, dissolves 14 wt % of Geon 101 vinyl chloride homopolymer at room temperature, whereas the solubUity of Geon 101 ia DMAC alone is about 5 wt % (15). 

Uses. Union Carbide consumes its vinyl ether production in the manufacture of glutaraldehyde [111-30-8J. BASF and GAF consume most of their production as monomers (see Vinyl polymers). In addition to the homopolymers, the copolymer of methyl vinyl ether with maleic anhydride is of particular interest. 

During the polymeriza tion process the normal head-to-tad free-radical reaction of vinyl chloride deviates from the normal path and results in sites of lower chemical stabiUty or defect sites along some of the polymer chains. These defect sites are small in number and are formed by autoxidation, chain termination, or chain-branching reactions. Heat stabilizer technology has grown from efforts to either chemically prevent or repair these defect sites. Partial stmctures (3—6) are typical of the defect sites found in PVC homopolymers (2—5). 

Itaconic acid, anhydride, and mono- and diesters undergo vinyl polymerization. Rates of polymerization and intrinsic viscosities of the resulting homopolymers ate lower than those of the related acrylates (see Acrylic ester polymers) (8,9). 

Diallyl Isophthalate. DAIP polymerizes faster than DAP, undergoes less cyclization, and yields cured polymers of better heat resistance, eg, up to ca 200°C. Prepolymer molding materials such as Dapon M of EMC, are not sticky. Maleic anhydride accelerates polymerization, whereas vinyl isobutyl ether retards it and delays gelation in castings. Copolymers with maleic anhydride are exceptionally hard and tough and may scratch homopolymer surfaces. 

Poly(vinyl alcohol) used to manufacture the poly(vinyl acetal)s is made from poly(vinyl acetate) homopolymer (see Vinyl polymers, vinyl alcohol polymers Vinyl POLYMERS, vinyl acetate polymers). Hydrolysis of poly(vinyl acetate) homopolymer produces a polyol with predominandy 1,3-glycol units. The polyol also contains up to 2 wt % 1,2-glycol units that come from head-to-head bonding during the polymeri2ation of vinyl acetate monomer. Poly(vinyl acetate) hydrolysis is seldom complete, and for some appHcations, not desired. For example, commercial PVF resins may contain up to 13 wt % unhydroly2ed poly(vinyl acetate). Residual vinyl acetate units on the polymer help improve resin solubiHty and processibiHty (15). On the other hand, the poly(vinyl alcohol) preferred for commercial PVB resins has less than 3 wt % residual poly(vinyl acetate) units on the polymer chain. 

The nmr spectmm of PVAc iu carbon tetrachloride solution at 110°C shows absorptions at 4.86 5 (pentad) of the methine proton 1.78 5 (triad) of the methylene group and 1.98 5, 1.96 5, and 1.94 5, which are the resonances of the acetate methyls iu isotactic, heterotactic, and syndiotactic triads, respectively. Poly(vinyl acetate) produced by normal free-radical polymerization is completely atactic and noncrystalline. The nmr spectra of ethylene vinyl acetate copolymers have also been obtained (33). The ir spectra of the copolymers of vinyl acetate differ from that of the homopolymer depending on the identity of the comonomers and their proportion. 

Economic Aspects. Prices for PVAc polymers depend on the form of the polymer, ie, whether it is resin or emulsion, homopolymer or copolymer, as well as on the specific product. As of 1994, emulsion prices were 0.57— 0.86/wet kg of resin. Prices of VAE copolymer emulsions tend to be higher than those of the homopolymer priced at 0.97— 1.43/wet kg. Vinyl acryUc copolymers Hsted for 0.66— 0.88/wet kg of 55% soHds emulsion (138). Specialty copolymers generally have a premium price. These price ranges are for large shipments. 

Poly(vinyl acetate) homopolymers adhere well to porous or ceUulosic surfaces, eg, wood, paper, cloth, leather (qv), and ceramics (qv). Homopolymer films tend to creep less than copolymer or terpolymer films. They are especially suitable in adhesives for high speed packaging operations. 

Copolymers wet and adhere well to nonporous surfaces, such as plastics and metals. They form soft, flexible films, in contrast to the tough, horny films formed by homopolymers, and are more water-resistant. As the ratio of comonomer to vinyl acetate increases, the variety of plastics to which the copolymer adheres also increases. Comonomers containing functional groups often adhere to specific surfaces for example, carboxyl containing polymers adhere well to metals. 

When more than routine water resistance is required, a copolymer vinyl acetate emulsion can be used. The plasticizing comonomer in the polymer particles increases their intrinsic coalescing ability thus, they can coalesce more readily than homopolymer particles to a film that has a higher resistance to water. This resistance to water does not extend to the organic solvents, however, which are better resisted by homopolymer films. The soft copolymers have lower solubility parameters than homopolymers and are more readily attacked by solvents of low polarity, eg, hydrocarbons. 

Poly(vinyl chloride) is Hsted on the TSCA inventory and the Canadian Domestic Substances List (DSL) as ethene, chloro-, homopolymer [9002-86-2]. Because polymers do not appear on the European Community Commercial Chemical Substances listing or EINECS, poly(vinyl chloride) is listed through its monomer, vinyl chloride [75-01-4]. In the United States, poly(vinyl chloride) is an EPA hazardous air pollutant under the Clean Air Act Section 112 (40 CER 61) and is covered under the New Jersey Community Right-to-Know Survey N.J. Environmental Hazardous Substances (EHS) List as "chloroethylene, polymer" with a reporting threshold of 225 kg (500 lb). 

As shown in Table 3, the glass-transition temperatures of the amorphous straight-chain alkyl vinyl ether homopolymers decrease with increasing length of the side chain. Also, the melting points of the semicrystalline poly(alkyl vinyl ether)s increase with increasing side-chain branching. 

---