T. Hirabayashi, T. Kawasaki, K. Yokota
Apr 1, 1990
Citations
0
Influential Citations
16
Citations
Journal
Polymer Journal
Abstract
The group transfer polymerization of 1-butadienyloxytrimethylsilane (BdTMS) was examined in the presence of various aldehyde and zinc chloride in benzene. The distribution of molecular weight of the resulting polymers, was estimated by a GPC method, depended on aldehydes used: Mw/Mn=1.28, 1.40, 1.51, and 1.86, with p-anisaldehyde, p-tolualdehyde, benzaldehyde, and p-nitrobenzaldehyde, respectively. In 1H NMR monitoring of the initial stage of polymerization, a certain induction period (T) was observed prior to consumption of BdTMS. The initial polymerization rate was almost constant regardless of a variety of aldehydes, indicating that propagation proceeds through a common mechanism. The shorter the induction period was, the narrower was the distribution of molecular weight of the obtained polymer. A plot of TH/TX (X=OCH3, CH3, NO2) vs. Brown-Okamoto’s substituent constants (σ+) showed a linear relationship (ρ=−0.75). Therefore a more electron-donating substituent on the para position of benzaldehyde was advantage to start an initiation reaction (=aldol addition) rapidly, resulting in a narrower distribution of the molecular weight of the polymer.