Polyethylene Vinyl Acetate Copolymer
These polymers will achieve superior performance in a wide range of solvent based adhesives including hobby glues parquet floor and laminating.
Polyethylene vinyl acetate copolymer. Ethylene vinyl acetate copolymer eva for instance is produced by the copolymerization of ethylene and vinyl acetate under pressure using free radical catalysts. Poly vinyl acetate was discovered in germany in 1912 by fritz klatte. Ethylene vinyl acetate eva copolymers are used in extrusion film processes for applications including packaging surface protection and greenhouse covers and in photovoltaic cell encapsulation. They are thermoplastic solids with a range of molecular weights typically supplied in the form of small beads.
Eva copolymers are more permeable to. Vinyl acetate c4h6o2 cid 7904 structure chemical names physical and chemical properties classification patents literature biological activities safety. Eva copolymers are used in molded caps and seals footwear and car interiors. Some applications require a 100 dry solids polymer that can be pre mixed with other solid additives.
On a weight basis ethylene is far more effective a fact that is reflected in the low tg of polyethylene homopolymer below 80 c. Poly ethylene vinyl acetate 1 product result match criteria. Synthomer s polyvinyl acetates homopolymers and acid copolymers of vinyl acetate. Many different grades are manufactured with the vinyl acetate content varying from 5 to 50 percent by weight.
Ethylene vinyl acetate eva also known as poly ethylene vinyl acetate peva is the copolymer of ethylene and vinyl acetate the weight percent of vinyl acetate usually varies from 10 to 40 with the remainder being ethylene. In addition poly vinyl acetate ethylene vae copolymers possess enhanced toughness flexibility and serviceability. There are three different types of eva copolymer which differ in the vinyl acetate va content and the way the materials are used. Selectophore 91 vinyl chloride 3 vinyl acetate 6 vinyl.
Both effects result in a lowering of the tg of the final copolymer. A copolymer having a vinyl acetate content of 28 wt shows a melting temperature of 70 c for the polyethylene crystallites. The cross linking does not significantly influence the melting temperature.