Polyurethane prepolymers for making elastomers having improved dynamic properties.

摘要

An isocyanate-terminated polyurethane prepolymer comprising the reaction product of a polyisocyanate and a polyol composition consisting essentially of a polyether polyol of 350-2000 equivalent weight and a low molecular weight polyol of 62 to <300 molecular weight, in an equivalent ratio of low molecular weight polyol to polyether polyol of 0.25-2.7:1. A polyurethane-urea elastomer having good dynamic properties can be prepared by reacting the isocyanate-terminated prepolymer with an aromatic amine chain extender at an equivalent ratio of 0.9-1.1:1.