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