Preparation of poly(methylfluorosiloxanes) by living anionic polymerization initiated with dilithium salt of N,N ′‐bis(diphenylhydroxysilyl)tetramethylcyclo‐disilazane

A bifunctional living poly(methyltrifluoro-propylsiloxane) PMTFS, was synthesized through the anionic ring-opening polymerization of trans 1,3,5-tri-methyl-1,3,5-tris(3',3',3'-trifluoropropyl) cyclotrisiloxane (trans-F 3 ) (3) with an initiator of dilithium salts (2) of N,N'-bis(diphenylhydroxysilyl)tetramethylcyclodisilazane (1) in ethyl acetate. The subsequent end-capping reaction of the bifunctional living PMTFs with dimethylvinyl-chlorosilane (4) provided the uniform size PMTFS having vinylsilane group at both chain ends.