SYNTHESIS AND CHARACTERIZATION OF POLY(3,4-BENZO-1-PHENYL-1-SILAPENTENE) AND POLY(3,4-BENZO-1-SILAPENTENE)

Low molecular weight poly(3,4-benzo-1-phenyl-1-silapentene) (I) has been prepared by the anionic ring opening polymerization of 3,4-benzo-1-phenyl-1-silacyclopentene (II), co-catalyzed by methyllithium and HMPA in THF at low temperature. Poly(3,4-benzo-1-silapentene) (III) has been prepared similarly by polymerization of 3,4-benzo-1-silacyclopentene (IV) except that HMPA has NOT been utilized in this latter case. I and III have been characterized by H-1, C-13, and Si-29 NMR as well as by IR and UV spectroscopy. The low molecular weight of I and III permits end group analysis by Si-29 NMR. The molecular weight distributions of I and III have been determined by gel permeation chromatography (GPC) and their thermal stability by thermogravimetric analysis (TGA).