Abstract: Styrene polymerization mediated by TEMPO was distinctly accelerated by the addition of small amounts of 2,2'-bipyridine(bpy). The polymerization proceeded in a living fashion as indicated by the increase in molecular weight with time and conversion and relatively  low polydispersities. It was found the polymerization was controlled well when the molar ratio of bpy/TEMPO equaled to 2/1. 135 ℃ was the optimal temperature for this system.1HNMR showed that bpy has a better control on styrene living polymerization.

Key words: stable free radical, living free radical polymerization, TEMPO, 2,2'-bipyridine