VINYLACETATE POLYMER

Biocides - [AMNES-CYCLOALIPHATIC AMINES] (Vol 2) - [INDUSTRIALANTIMICROBIALAGENTS] (Vol 14) - [THERMAL POLLUTION] (Vol 23) -m adhesives [VINYL POLYMERS - VINYLACETATE POLYMERS] (Vol 24) -dicyandiarmdes m [CYANAMIDES] (Vol 7) -m grouts [SOIL STABILIZATION] (Vol 22) -mtro alcohols as [NITRO ALCOHOLS] (Vol 17) -m papermaking [PAPERMAKING ADDITIVES] (Vol 18) -m papermaking [PAPERMAKING ADDITIVES] (Vol 18) -PVC as [VINYL POLYMERS - VINYL CHLORIDE POLYMERS] (Vol 24) -quaternary ammonium compounds as [QUATERNARY AMMONIUM COMPOUNDS] (Vol 20)... 

VINYLPOLYMERS - VINYLACETATE POLYMERS] (Vol 24) -treatment of [GEMSTONES - GEMSTONE TREATMENT] (Vol 12)... 

Polymers in Schemes 12 and 13 were the first examples of the preparation of pyridinium and iminopyridinium ylide polymers. One of the more recent contributions of Kondo and his colleagues [16] deals with the sensitization effect of l-ethoxycarbonyliminopyridinium ylide (IPYY) (Scheme 14) on the photopolymerization of vinyl monomers. Only acrylic monomers such as MMA and methyl acrylate (MA) were photoinitiated by IPYY, while vinylacetate (VA), acrylonitrile (AN), and styrene were unaffected by the initiator used. A free radical mechanism was confirmed by a kinetic study. The complex of IPYY and MMA was defined as an exciplex that served as a precursor of the initiating radical. This ylide is unique in being stabilized by the participation of a... 

Maleimides Alkyl and aryl maleimides in small concentrations, e.g., 5-10 wt% significantly enhance yield of cross-link for y-irradiated (in vacuo) NR, cw-l,4-polyisoprene, poly(styrene-co-butadiene) rubber, and polychloroprene rubber. A-phenyhnaleimide and m-phenylene dimaleimide have been found to be most effective. The solubihty of the maleimides in the polymer matrix, reactivity of the double bond and the influence of substituent groups also affect the cross-fink promoting ability of these promoters [82]. The mechanism for the cross-link promotion of maleimides is considered to be the copolymerization of the rubber via its unsaturations with the maleimide molecules initiated by radicals and, in particular, by allyfic radicals produced during the radiolysis of the elastomer. Maleimides have also been found to increase the rate of cross-linking in saturated polymers like PE and poly vinylacetate [33]. 

The techniques of paraffin removal and paraffin prevention have been reviewed [810]. In particular, inhibitors for paraffin deposits are copolymers of ethylene with vinylacetate [525-527,1597] or polymers from p-nonylphenyl methacrylate and p-dodecylphenyl methacrylate [773]. These materials lower the pour point of the oil. It has been shown that for oils which differ in the content of n-paraffins and asphalt-resinous substances, it is necessary to use blends of copolymers of different compositions and molecular weights to obtain optimal efficiency. Polyacrylamide and wastes from the production of glycerol with a concentration of 400 mg/liter of oil have also been claimed to be effective as paraffin inhibitors [536]. 

For the formation of microgels the presence of a crosslinking monomer is not always necessary. Thus, microgels have also been detected in polymers prepared with bifunctional monomers, e.g. poly(acrylonitrile-co-vinylacetate) [39], polyethylene [40],poly(vinylchloride) [41] andpoly(vinylidenefluoride) [42].Obviously, the reason for the intramolecular crosslinking with the formation of microgels are side reactions. 

A-Vinylpyrrolidone polymers are of special interest in medicine in the process of detoxification as well as for binding and removal of undesirable metallic ions and known as chelatotherapeutic agents [34]. Free radical copolymers of poly(lV-vinylpyrrolidone) and copolymer of JV-vinylpyrrolidone and vinylacetate, vinylamine, vinylamidosuceinic arid are known to bind Cu2+ and other transition metal ions, and the resultant complexes exhibit interesting physico-chemical properties. 

Ethyl n-propylmalonate, 486 Ethyl n-propyl ketone, 340 4-Ethylpyridine, 844 Ethyl 2-pyridylacetate, 931, 932 Ethyl salicylate, 783 Ethyl sulphite, 304 Ethyl -valerate, 382, 389 Ethyl vinylacetate, 382, 389 Ethylenediamine-adipic acid polymer, 1019,1025 Ethylene glycol, 285 Ethylene glycol, monoalkyl ethers of, 170, 444... 

Figure 10. Density of different polymer latex particles as a function of centrifugation time (N = 40.000 min 1) (Y ) polyvinyl acetate (%) poly(vinylacetate-co-ethylene) (A) polystyrene (X) poly( butadiene-co-styrene) (O) poly butadiene)...

All the above examples involve charge transfer complexes between monomer units of the polymer and an added electron acceptor. There have been several cases reported in which both donor and acceptor groups become parts of the structure of the same polymer. For example, strong electron acceptor groups such as dinitro-phenyl and chloranil were chemically attached to copolymers of N-vinylcarbazole with vinylacetate or acryloyl chloride158) ... 

Copolymers of PE with vinylacetate, acrylic acid ester and methacrylic acid increase the heat sealability, adhesion to other materials and seal strength and they improve the polymer s cold resistance and transparency. EVA in the form of shrink films are well suited for meat packaging because of their relatively high gas permeabilities. 

Internal plasticizers are synthesized by copolymerization of suitable monomers. Polymeric non-extractable plasticizers, mostly copolymers having substantially lower glass transition temperatures due to the presence of plasticizing ( soft ) segments such as poly(ethylene-co-vinyl acetate) with approximately 45 % vinylacetate content, ethylene-vinyl acetate-carbon monooxide terpolymer, or chlorinated PE, are available for rather special applications in medicinal articles (Meier, 1990). In this case, the performance of the internally plasticized polymers is the principal advantage. However, copolymerization may account for worse mechanical properties. A combination with external plasticizers may provide an optimal balance of properties. For example, food contact products made from poly(vinylidene chloride) should have at most a citrate or sebacate ester based plasticizers content of 5 % and at most 10 % polymeric plasticizers. 

Grafting of Monomer to Surface-Active Agents. A recent patent claims the preparation of a F/T stable poly(vinylacetate-vinylbenzoate) copolymer emulsion in the presence of a graft polymer of vinylacetate on a polyalkylene glycol (21). 

Alternating copolymers -A-B-A-B-A-B- Vinylacetate-maleic anhydride-copolymers Condensation polymers of diamines and diacids... 

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