Thermoplastic polyurethane hydrolysis stability

Abstract

Abstract This paper reviews several types of thermoplastic polyurethane elastomers, and the unique properties these polymers have. In discussing the hydrolysis stability of thermoplastic polyurethane elastomers the suitability of these polymers for such study was pointed out. A relationship between poly(ester‐urethane) composition in terms of methylene group concentration, hardness and chain stiffness, and hydrolysis stability was shown. The dominant role of polyurethane acid number in thermoplastic poly(ester‐urethane) hydrolysis stability was demonstrated and the origin of this unexpected acid number was discussed. The pronounced stabilizing action of added poly(carbodiimide) in thermoplastic poly(ester‐urethane) hydrolysis was shown, as well as the severe destabilizing action of a carboxylic acid, stearic acid. The hydrolysis stabilities of thermoplastic poly(ester‐urethane) elastomers based on poly(ϵ‐caprolactone) glycol and on poly(hexamethylene carbonate) glycol were also described.