Synthesis of well-defined polystyrene by radical polymerization using 1,1,2,2-tetraphenyl-1,2-ethanediol/FeCl3/PPh3 initiation system

Well-defined polystyrenes with an a-hydrogen atom and an omega-chlorine ato m end groups and narrow polydispersity (M-n = 2500-4200, M-w/M-n = 1.29-1.4 8) have been-synthesized by a free radical polymerization process using a 1 ,1,2,2-tetraphenyl-1,2-ethanediol (TPED)/FeCl3/PPh3 initiation system. The end groups were monitored by H-1 nuclear magnetic resonance spectroscopy. W hen the polymerization of styrenes in bulk carried out at 120 degrees C and the ratio of [St](0): [TPED](0): [FeCl3](0): [PPh3](0) was 200 : 1 : 4 : 1 2, the polymerization exhibited some living/controlled radical polymerizati on characteristics. The polymerization mechanism was proposed proceeding vi a a reverse atom transfer radical polymerization (ATRP). Because the polyme rs obtained were end-functionalized by chlorine atoms, they were used as ma croinitiators to proceed chain extension polymerization in the presence of CuCl/2,2'-bipyridine catalyst system via a conventional ATRP process. (C) 2 000 John Wiley & Sons, Inc.