. "attached to the polymer chain, the ratio of the ethylene to said .comonomer in the copolymer varying from 1:1 to 30:1, the molecular weight of the copolymer being sufliciently high .to give the copolymer a melting point above 70 C. Comonomers which results in copolymers having polar groups attached to the carbon chain of the molecule are such compounds as carbon monoxide, vinyl acetate, vinyl alco" . . . . .