A thermoplastic polyurethane characterized by high impact resistance, high flexural modulus, and a heat deflection temperature of at least 50.degree. C. at 264 psi which comprises the product of reaction of:
- (a) an organic diisocyanate;
- (b) an isocyanate-reactive material having an average functionality of at least 1.9, a glass transition temperature (Tg) of less than 20.degree. C., and a molecular weight in the range of about 500 to about 20,000;
- and
- (c) at least one chain extender diol having a molecular weight from about 50 to about 400;
- said polyurethane being further characterized in that the proportion by weight of said component (b) in said polyurethane is from about 2 to about 25 percent and the overall ratio of isocyanate groups to active hydrogen groups in said reactants employed to prepare said polyurethane is in the range of about 0.95:1 to about 1.05:1.