Polymerisation via Zwitterionen

Abstract

Zwitterions and ylides were for a long time considered to be inadequate to initiate ionic polymerization. Recently however, it has been proved that such reactions are possible. The polymerization is initiated either through zwitterions or ylides, prepared directly from tert. phosphines or similar substances and an appropriate monomer, or through addition of the free ylide to the monomer. As monomers are to be considered, in particular, all unsaturated compounds or lactones capable of undergoing anionic polymerization. Such polymerizations generally lead to the formation of macro zwitterions. The reaction scheme is discussed with the help of a few examples.