NOVEL PLATINUM INITIATORS FOR RING-OPENING POLYMERIZATIONS

Platinum complexes together with compounds containing silicon-hydrogen bonds comprise a novel class of initiators for the ring-opening polymerization of a wide variety of heterocyclic compounds including; epoxides, oxetanes and 1,3,5-trioxane. This paper reports on a preliminary survey of the scope and limitations of these new initiator systems with special emphasis on the ring-opening polymerization of epoxides. Considerable effort has been directed towards the elucidation of the mechanism of the polymerizations initiated by these systems. The best current evidence suggests that polymerization proceeds by a cationic mechanism. Data is also presented which suggests that platinum metal colloids may function as the active initiating species.