Disclosed are copolymers derived from ethylene and an alkyl acrylate comonomer wherein the copolymer has a number average molecular weight (M.sub.n) above 40,000. This invention also provides compounded compositions and cured compositions (i.e., vulcanizates) comprising these copolymers. The copolymers provide improved dynamic fatigue resistance of the vulcanizates. Also disclosed are articles comprising the copolymers, such as tubing, hoses, dampers, seals and gaskets.