TRIMETHYLSILYLMETHYLLITHIUM - A NOVEL INITIATOR FOR THE ANIONIC-POLYMERIZATION OF CYCLOSILOXANES AND VINYL MONOMERS

Trimethylsilymethyllithium has been successfully used for the ring ope ning polymerization of cyclosiloxanes, in toluene or in the bulk, with the [211] cryptand or DMSO as promoters. Initiation reaction has been followed by H-1, C-13, Si-29 and Li-7 NMR in the case of D3 and D4 po lymerizations. Suitable conditions have been found in which monomodal distributions of molecular weights of polysiloxanes are observed even in the case of D4 and 7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxa ne homopolymerizations and copolymerizations. This organolithium compo und can also initiate the anionic polymerization of vinyl monomers suc h as butadiene, styrene and MMA.