Trimethylsilylmethyllithium: A novel initiator for the anionic polymerization of cyclosiloxanes and vinyl monomers

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