Controlled radical polymerization of styrene utilizing excellent radical capturing ability of diphenyl ditelluride

The radical polymerization of styrene was investigated in the presence of d iphenyl ditelluride (DPDTe) under varied conditions. In the polymerization without any radical initiator at higher temperature (125 degrees C), the ad dition of DPDTe surely decreased the polymer molecular weight (M-n while th e polydispersity (M-w/M-n) was rather broad. The polymerization with benzoy l peroxide (BPO) as the initiator was also uncontrollable to afford polymer s with broad M-w/M(n)probably due to the redox side reaction of BPO with DP DTe. On the contrary, the precision control of M-n and the initiating end s tructure could be achieved by the polymerization with 2,2'-azobisisobutyron itrile (AIBN), that is, M-n increased in proportion to the molar ratio of m onomer to initiator suggesting the suppression of bimolecular chain termina tion reactions by the excellent radical capturing ability of DPDTe.