Bulk polymerization of styrene with diethyl 2,3-dicyano-2,3-di(p-tolyl)-succinate as a thermal iniferter

The bulk polymerization of styrene (St) was investigated using diethyl 2,3- dicyano-2,3-di(p-tolyl)succinate (DCDTS), a hexa-substituted ethane compoun d, as an initiator. The polymerization data show that DCDTS behaves as a th ermal iniferter, and the polymerization proceeds by a "living" radical poly merization mechanism with a reversible deactivation. The polymerization can be carried out at quite low temperatures (such as 65-85 degreesC) and the final conversions are high. The PSt possessed high molecular weights and mo lecular weight distributions (M-w/M-n in the range of 1.4 to 1.6). End-grou p analysis by H-1 NMR spectroscopy reveals that the resultant PSt contains the fragments of DCDTS at its chain ends. This polymer with an omega -penta -substituted C-C bond end group could be used as a macroinitiator to carry out chain-extension reaction with St and could also block copolymerization with methyl methacrylate.