Ethylene/vinyl acetate inhibition

Ethylene dichloride (5) Ethylene dichloride (5) Ethylene glycol (6) Ethylene glycol (6) Ethylene glycol (6) Caustic soda solution (3) Diphenylmethanediisocyanate Ethyl acrylate (inhibited) (14) Styrene (inhibited) (14) Vinyl acetate (inhibited) (14)... 

The compatibility of blends of poly (vinyl chloride) (PVC) and a terpolymer (TP) of ethylene, vinyl acetate, and carbon monoxide was investigated by dynamic mechanical, dielectric, and calorimetric studies. Each technique showed a single glass transition and that transition temperature, as defined by the initial rise in E" at 110 Hz, c" at 100 Hz, and Cp at 20°C/min, agreed to within 5°C. PVC acted as a polymeric diluent which lowered the crystallization temperature, Tc, of the terpolymer such that Tc decreased with increasing PVC content while Tg increased. In this manner, terpolymer crystallization is inhibited in blends whose value of (Tc — Tg) was negative. Thus, all blends which contained 60% or more PVC showed little or no crystallinity unless solvent was added. 

SYNS ACETATE de VINYLE ACETIC ACID, ETHENYL ESTER ACETIC ACID, ETHYLENE ETHER ACETIC ACID VINYL ESTER 1-ACETOXYETHYL-ENE ETHANOIC ACID, ETHENYL ESTER ETHENYL ACETATE ETHENYL ETHANOATE OCTAN WINYLU (POLISH) VAC VINILE (ACETATO i) (ITALIAN) VINYLACETAAT (DUTCH) VINYLACET-AT (GERMAN) VINYL ACETATE, inhibited (DOT) VINYL ACETATE H.Q. VINYL A MONOMER VINYLE (ACETATE de) (FRENCH) VINYLESTER KYSELINY OCTOVE VINYL ETHANOATE VYAC ZESETT... 

Synonyms Acetic acid, ethenyl ester Acetic acid, ethylene ether Acetic acid, vinyl ester 1-Acetoxyethylene Ethanoic acid, ethenyl ester Ethenyl acetate Ethenyl ethanoate VAc VAM Vinyl acetate, inhibited Vinyl acetate monomer Vinyl ethanoate... 

Synonyms Acetic acid, ethenyl ester Acetic acid, ethylene ether Acetic acid, vinyl ester 1-Acetoxyethylene Ethanoic acid, ethenyl ester Ethenyl acetate Ethenyl ethanoate VAc VAM Vinyl acetate, inhibited Vinyl acetate monomer Vinyl ethanoate Ciassiflcation Unsaturated carboxylic acid ester Empiricai C4H6O2 Formuia CH3COOCH=CH2 Properties Colorless liq. char, odor polymerizes in light to a colorless transparent mass sol. 1 g/50 ml water (20 C) sol. in ethanol, ether, acetone, benzene, chloroform, mostorg. soivs. m.w. 86.09 dens. 0.932 (20/4 C) vapor pressure 100 mm (21.5 C) m.p. -93 C b.p. 71-73 C flash pt. (CC) -8 C... 

If either of the comonomers on its own could yield a crystalline homopolymer, then copol5mierization can have a very marked effect on properties by inhibiting crystallization. For example, PE crystallinity is decreased by increasing the amoimt of vinyl acetate content in the copolymer leading to a softer, tougher product, namely, ethylene-vinyl acetate (EVA). 

In particular in halogen-free systems, there are major advantages with respect to smoke suppression, afterglow suppression, corrosion inhibition, by combining zinc borates with other flame retardants in certain polymers, such as ethylene vinyl acetate, polyfvinyl chloride), poly(amide) (PA). 

Olefins add anhydrous acetic acid to give esters, usually of secondary or tertiary alcohols propjiene [115-07-1] yields isopropyl acetate [108-21-4], isobutjiene [115-11-7] gives tert-huty acetate [540-88-5]. Minute amounts of water inhibit the reaction. Unsaturated esters can be prepared by a combined oxidative esterification over a platinum group metal catalyst. Eor example, ethylene-air-acetic acid passed over a palladium—Hthium acetate catalyst yields vinyl acetate. 

There is a tendency toward alternation in the copolymerization of ethylene with carbon monoxide. Copolymerizations of carbon monoxide with tetrafluoroethylene, vinyl acetate, vinyl chloride, and acrylonitrile have been reported but with few details [Starkweather, 1987]. The reactions of alkenes with oxygen and quinones are not well defined in terms of the stoichiometry of the products. These reactions are better classified as retardation or inhibition reactions because of the very slow copolymerization rates (Sec. 3-7a). Other copolymerizations include the reaction of alkene monomers with sulfur and nitroso compounds [Green et al., 1967 Miyata and Sawada, 1988]. 

Levels of acrylic acid higher than 1.5% inhibit the batch copolymerization reaction of ethylene and vinyl acetate. 

Sections of polymer chains must be capable of packing together in ordered periodic arrays for crystallization to occur. This requires that the macromolecules be fairly regular in structure. Random copolymerization will prevent crystallization. Thus, polyethylene would be an ideal elastomer except for the fact that its very regular and symmetrical geometry permits the chains to pack together closely and crystallize very quickly. To inhibit crystallization and confer elastomeric properties on this polymer, ethylene is commonly copolymerized with substantial proportions of another olefin or with vinyl acetate. 

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