METHOD FOR PRODUCING A POLYDIORGANOSILOXANE HAVING A PENDENT ALKENYL RADICAL AT ITS MOLECULAR CENTER

摘要

Polydlorganosiloxanes which have a pendant alkenyl radical in the middle of the molecular chain are prepared by a nonequilibrium, living polymerization of cyclic trisiloxanes using an organopolysiloxane alkali metal salt of the formula where M is lithium, sodium, or potassium, which takes place under substantially anhydrous conditions, and the polymerization is terminated with an end-capping reaction to produce a polydiorganosiloxane of the formula where R1 is an alkenyl radical. These polymers can be used to make graft copolymers and can be made more functional when the ends are capped with functional groups.