Tetraphenylethane iniferters: Polyurethane-polystyrene multiblock copolymers through “living” radical polymerization

Toluene diisocyanate-based polyurethane iniferters containing tetraphenyl-ethane groups in between polyurethane blocks were prepared by the reaction of isocyanate-terminated prepolymers and 1,1,2,2-tetraphenyl-1,2-ethanediol. When these iniferters were decomposed in the presence of styrene, polyurethane-polystyrene multiblock copolymers were obtained through a “living” radical mechanism. The effect of changing polyol on the T_g, thermal stability, and molecular weight of polyurethane iniferters as well as block copolymers was studied. The molecular weight of the block copolymers increased with increasing both polymerization time and conversion. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1551–1560, 1997