BASIC STRUCTURE-PROPERTY BEHAVIOR OF UV CURABLE POLYURETHANE ACRYLATES

Effects of hard segment type, soft segment type, soft segment length, and crystallization at various levels of reactive diluent have been st udied in polyurethane acrylates. PTMG-IPDI-based PU acrylates gave bet ter soft segment-hard segment phase separation as compared with PTMG-T DI-based ones. Among PTMG-, PCL-, and PTAd-IPDI-based materials, only PTMG-based one gave clean phase separation, and PTAd-based gave the po orest phase separation. With greater phase separation, higher modulus was obtained. Crystallization of soft segment in PTAd-IPDI-based mater ial gave a significant increase in tensile modulus and elongation at b reak, with a notable difference in dynamic mechanical properties. (C) 1996 John Wiley & Sons, Inc.