Ethylene Vinyl Acetate Copolymer Uses

26 eva copolymers usually comprising a vinyl ester content of 15 40 have been identified to be effective flow improvers for crude oils and middle distillates.

Ethylene vinyl acetate copolymer uses.

The food and drug administration fda has stated that ethylene vinyl acetate is safe when used in food production packaging or transportation and it s not an especially dangerous material. Eva is used in several applications thanks to the varied properties it possesses. Vinyl acetate is the acetate ester of vinyl alcohol. 27 29 however due to its polarity only solutions.

As the va content increases crystallinity decreases until at 50 the eva is. Ethylene vinyl acetate properties ethylene vinyl acetate is a flexible and transparent thermoplastic. The significance and features of ethylene vinyl acetate eva copolymers in initial research and development led to commercial drug delivery systems. On a weight basis ethylene is far more effective a fact that is reflected in the low tg of polyethylene homopolymer below 80 c.

The va comonomer interferes with chain packing reducing crystallinity and thus lowering t m and improving transparency when compared with ldpe. Emblem in packaging technology 2012. Also it imparts plastic like properties that enable wax to compete effectively with high quality polymeric coatings. The major industrial route involves the reaction of ethylene and acetic acid with oxygen in the presence of a palladium catalyst.

Since vinyl alcohol is highly unstable with respect to acetaldehyde the preparation of vinyl acetate is more complex than the synthesis of other acetate esters. Incorporating ethylene vinyl acetate eva copolymer in the pama is also another modification strategy which is useful in the heavy fuel or crude oil flow improver application. 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. It shows good chemical resistance.

Eva ethylene vinyl acetate this copolymer resin can be used in adhesives sealants and coatings. Ethylene vinyl acetate is a type of plastic a polymer with a wide variety of uses both residential and industrial. In addition poly vinyl acetate ethylene vae copolymers possess enhanced toughness flexibility and serviceability. It is the basis of many hot melt adhesives when blended with a petroleum wax and a resin tackifier.

Eva shows good barrier and stretch properties. There are three different types of eva copolymer which differ in the vinyl acetate va content and the way the materials are used. Both effects result in a lowering of the tg of the final copolymer. This review examines the breadth of eva use in drug delivery and will aid the researcher in locating key references and experimental results as well as understanding the features of eva as a highly versatile biocompatible polymer for drug.

Eva based hot melts are able to fulfill various requirements in applications such as packaging bookbinding or label sticking.