A new generation of polyurethane thermoplastic elastomers were synthesized via the reaction of NCO-terminated polyurethane with 2,2'-pyromellitdiimidodisuccinic anhydride chain extender. The starting materials and polymers were characterized by conventional methods and physical, mechanical and thermal properties were studied. In comparison to typical polyurethanes, these polymers exhibited improved thermal stability as well as good processability and flexibility. (C) 2003 Elsevier Ltd. All rights reserved.