New developments in cationic polymerization of cyclosiloxanes

Abstract

Some recent publications5-8 have shown the analogies or the differences in the behavior of cyclosiloxanes of various sizes (particularly D3 and D4) when they are initiated by triflic acid. They are discussed in the present article, the analogies being found mainly in the general kinetics, and the differences in the rates, in the nature of the cyclic oligomers formed, and in the effect of water on the reaction. New data are given, for D3 polymerization, on the absence of reaction with triflate esters in the absence of acid or water, on the effect of water on polymerization and on the variation of the polymer mol wt with conversion. Even if it is too early to come to definite conclusions about the nature of the different types of active species, the various possibilities are discussed. © 1987 The Society of Polymer Science, Japan. All rights reserved.