Icosahedral Carboranes. Xvi. Polymerization and Crosslinking Mechanism of Poly-M-Carboranylene-Siloxanes

摘要

The FeCl3 catalyzed bulk polymerization of a bis-(methoxysilyl)-m-carborane and a dichlorosilane resulting in a poly-m-carboranylenesiloxane raw gum (DEXSIL 200) was found to occur in three distinct parts: First, the low temperature polymerization stage which includes end group exchange and the subsequent formation of polydimethyl-siloxanes, second, the high temperature polymerization stage in which equilibration between carborane monomers and the polysiloxane occurs to produce polymeric material approximating DEXSIL 200 in composition, and third, the foaming stage in which the polymer chains are crosslinked to provide insoluble DEXSIL raw gum. (Author)