Copolyether-esters as additives for fiber-reinforced polyethylene terephthalate

摘要

Fiber-reinforced polyethylene terephthalate molding compositions containingPP(A) about 20 to about 80% by weight of polyethylene terephthalate;PP(B) about 5 to about 50% by weight of a reinforcing fiber; andPP(C) about 6 to about 60% by weight of a copolyether-ester consisting essentially ofP P(a) long-chain ester units having the formula: ##STR1## wherein G is the divalent radical remaining after removal of the terminal hydroxyl groups from a poly(alkylene oxide) glycol having a number- average molecular weight of about 400 to about 6000; and R is the divalent radical remaining after removal of the carboxyl groups from a dicarboxylic acid; andPP(b) short- chain ester units having the formula: ##STR2## wherein D is the divalent radical remaining after removal of the hydroxyl groups from a low molecular weight diol having a molecular weight of less than about 250; and R is as defined above;PP with the proviso that the short-chain ester units constitute about 40 to about 90% by weight of the polyether-ester, and the long-chain ester units constitute about 10 to about 60% by weight of the copolyether-esterPPprovide injection molded articles having improved surface smoothness.