TETRAPHENYLETHANE INIFERTERS - POLYURETHANE-POLYSTYRENE MULTIBLOCK COPOLYMERS THROUGH LIVING RADICAL POLYMERIZATION

Toluene diisocyanate-based polyurethane iniferters containing tetraphe nylethane groups in between polyurethane blocks were prepared by the r eaction of isocyanate-terminated prepolymers and 1,1,2,2-tetraphenyl-1 ,2-ethanediol. When these iniferters were decomposed in the presence o f styrene, polyurethane-polystyrene multiblock copolymers were obtaine d through a ''living'' radical mechanism. The effect of changing polyo l on the T-g, thermal stability, and molecular weight of polyurethane iniferters as well as block copolymers was studied. The molecular weig ht of the block copolymers increased with increasing both polymerizati on time and conversion. (C) 1997 John Wiley & Sons, Inc.