Rubbery Copolymers of Ethylene with Polar Monomers

RUBBERY COPOLYMERS OF ETHYLENE WITH POLAR MONOMERS 

Such considerations lead to the conclusion that suitable monomers 

Like the ethylene-propylene copolymer rubbers these rubbers are saturated and exhibit good oxygen, ozone and heat ageing resistance whilst those based on methyl acrylate also have some claim to oil resistance. 

The ethylene-vinyl acetate rubbers have been available for some years (Levapren 450—Bayer) and contain about 45% vinyl acetate units. They are vulcanized by peroxides such as dicumyl peroxide, t-butyl cumyl peroxide, di-t-butyl peroxide and 2,5-bis(t-butyl peroxy)-2,5-dimethyl hexane. 

The ethylene-methyl acrylate rubbers were introduced in 1975 (Vamac—Du Pont) and are prepared from ethylene, methyl acrylate and a small amount of a third monomer to provide a cure site. The polymer is said to have the following structure  

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