Effect of imide-oxazolidinone modification on the thermal and mechanical properties of HTPB-polyurethanes

Imide- and oxazolidinone-incorporated polyurethanes, based on hydroxy-termi nated polybutadiene (HTPB), were synthesized and characterized. Reaction of the blocked isocyanate terminals of the HTPB prepolymer with diepoxy compo unds, containing preformed imide groups, was the strategy followed. The die poxy resins were derived through reaction of an aliphatic and an aromatic d icarboxylic acid with preformed imide groups with a diepoxy resin. The inte rmediates and the polyurethane-imide-oxazolidinone were characterized by ch emical, spectral, and elemental analyses. Incorporation of these heterocycl ic groups caused dramatic improvements in the thermal and mechanical proper ties and the thermomechanical profile of the system. The improvements in pr operties were proportional to the hard-segment content of the modified poly urethanes. (C) 1999 John Wiley & Sons, Inc.