MICROSTRUCTURES OF POLY(1-BUTADIENYLOXYTRIMETHYLSILANE)S PREPARED BY ALDOL CONDENSATION-TYPE GROUP-TRANSFER POLYMERIZATION

Three polymers of 1-butadienyloxytrimethylsilane (BdTMS), 3-methyl-1-b utadienyloxytrimethylsilane (MeBdTMS), and 3-phenyl-1-butadienyloxytri methyisilane (PhBdTMS) were prepared by aldol condensation-type group transfer polymerization. Microstructures of these polymers were determ ined by H-1 and C-13 NMR. Content of trans-1,4 unit in poly(BdTMS), po ly(MeBdTMS), and poly(PhBdTMS) decreased in that order, reflecting s-c onformation of monomer. The results suggest that this polymerization p roceeds via a bicyclic transition state made up of a monomer, propagat ing chain end, and catalyst, Poly(BdTMS) contained 14% a 3,4 unit, but poly(MeBdTMS) and poly(PhBdTMS) did not. This suggests that formation of the 3,4 unit depends on the structure of propagating chain end.