Mechanical and Thermal Properties of Networks Prepared from Reactive Poly(urethane-imide)s and Blocked Polyurethane Prepolymer

Abstract

Reactive poly(urethane-imide)s with varying functionality were prepared using 4,8-diphenyl-1,5-diazabicyclo(3.3.0)octane-2,3,6,7-tetracarboxylic dianhydride, 4,8-(di-p-phenylol)-1,5-diazabicyclo(3.3.0)octane-2,3,6,7-tetracarboxylic dianhydride and N-methylaniline blocked polyurethane prepolymer (1). The resulting polymers with reactive phenylol groups, pendent in the dianhydride, were treated with 1 to give poly(urethane-imide) networks. The cast films were characterized by FT-IR, TG, static and dynamic mechanical analyses. Thermal stability of the polymers was found to be higher than that of the conventional polyurethane. Higher cross-linking leads to lower damping and improved strength.