POLYURETHANE ELASTOMERS EXHIBITING IMPROVED DEMOLD, GREEN STRENGTH, AND WATER ABSORPTION, AND HAZE-FREE POLYOLS SUITABLE FOR THEIR PREPARATION.

摘要

Polyurethane elastomers exhibiting improved green strength while maintaining short demold times are prepared from ultra-low unsaturation polyoxypropylene polyols containing up to 20 weight percent internal random oxyethylene moieties. The elastomers adsorb less than 10 weight percent water at 0 degree . The internal polyoxyethylene moiety-containing polyoxypropylene polyols may be used to prepare ultra-low unsturation polyoxyethylene capped polyols which are haze-free and which may be used to prepare haze-free 4,4'-MDI prepolymers. Multidisperse blends of monodisperse internal oxyethylene moiety-containing polyoxypropylene polyols of ultra-low unsaturation provide ywt further improvements in elastomer processing.