Toughening of cured vinyl ester resins by inclusion in the uncured resins of oligomeric vinyl-reactive urethanes which phase out upon curing

摘要: Vinyl ester/styrene mixtures are flexibilized by addition thereto of minor amounts urethanes which (1) comprise at least one polyglycol moiety and two urethane groups terminated vinyl-reactive end groups, (2) form a dispersed second phase in the cured mixture. The compositions otherwise largely retain characteristic properties unflexibilized mixtures.