Ethylene-vinyl acetate

Ethylene-vinyl acetate

Names
Other names Poly(ethylene-vinyl acetate); Poly(ethylene-co-vinyl acetate); Polyethylene-vinyl acetate copolymer
Identifiers
CAS Number	24937-78-8 Y
Abbreviations	EVA; PEVA
ECHA InfoCard	100.133.085
PubChem	32742
UNII	4OKC630HS6 Y
Properties
Chemical formula	(C2H4)n(C4H6O2)m
Molar mass	Variable
Hazards
Safety data sheet	MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Ethylene-vinyl acetate (EVA), also known as poly (ethylene-vinyl acetate) (PEVA), is the copolymer of ethylene and vinyl acetate. The weight percent vinyl acetate usually varies from 10 to 40%, with the remainder being ethylene.

Broadly speaking, there are three different types of EVA copolymer, which differ in the vinyl acetate (VA) content and the way the materials are used.

The EVA copolymer which is based on a low proportion of VA (approximately up to 4%) may be referred to as vinyl acetate modified polyethylene. It is a copolymer and is processed as a thermoplastics material – just like low density polyethylene. It has some of the properties of a low density polyethylene but increased gloss (useful for film), softness and flexibility. Generally considered as a non-toxic material.

The EVA copolymer which is based on a medium proportion of VA (approximately 4 to 30%) is referred to as thermoplastic ethylene-vinyl acetate copolymer and is a thermoplastic elastomer material. It is not vulcanized but has some of the properties of a rubber or of plasticized polyvinyl chloride particularly at the higher end of the range. May be filled and both filled and unfilled materials have good low temperature properties and are tough. The materials with approximately 11% VA are used as hot melt adhesives.

The EVA copolymer which is based on a high proportion of VA (greater than 40%) is referred to as ethylene-vinyl acetate rubber.

EVA is an elastomeric polymer that produces materials which are "rubber-like" in softness and flexibility. The material has good clarity and gloss, low-temperature toughness, stress-crack resistance, hot-melt adhesive waterproof properties, and resistance to UV radiation. EVA has a distinctive vinegar-like odor and is competitive with rubber and vinyl products in many electrical applications.

Hot melt adhesives (such as hot glue sticks) and top of the line soccer cleats are usually made from EVA, usually with additives like wax and resin. EVA is also used as a clinginess-enhancing additive in plastic wraps. Craft foam sheets are made of EVA and are popularly used for children's foam stickers.