Anionic polymerization of cyclosiloxanes in heterogeneous medium

Abstract

Anionic polymerization of various cyclosiloxanes [octamethylcyclotetrasiloxane (D4), 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (V4), and hexamethylcyclotrisiloxane (D3)] was performed. As catalysts, IRA-900 and PB-100 type anionites with benzyltrimethylammonium and 3-acrylamidopropylbenzyldimethylammonium groups, respectively, were used. The anionite with higher strongly basic exchange capacity (IRA-900) is more efficient in dimethylcyclosiloxane polymerization. PB-100 anionite with less strongly basic capacity is more active for polymerization of the V4 monomer with bulky and electronegative substituent.