GROUP-TRANSFER POLYMERIZATION ON A POLYMERIC SUPPORT

Three silyl ketene acetals (4, 7, and 9) bonded to cross-linked polystyrene beads were synthesized from chloromethylated polystyrene. Suspensions of these supported silyl ketene acetals in tetrahydrofuran (THF) containing methyl methacrylate (MMA) and anion catalysts for group-transfer polymerization (GTP) gave rapid formation of graft polymers, almost without formation of ungrafted, soluble PMMA. Initiation of the GTP of MMA with 7 in acetonitrile gave insignificant chain transfer to solvent. Initiation of the GTP of acrylonitrile with 9 at -50 °C gave quantitative conversion to graft copolymer, while initiation at room temperature gave soluble poly(acrylonitrile) as well. In contact with gaseous MMA or acrylonitrile, catalyst-doped 4 was converted to graft copolymer. The GTP of MMA in THF solution in the presence of cyanomethyl-substituted cross-linked polystyrene beads (1) gave a graft copolymer as a result of chain transfer. © 1990, American Chemical Society. All rights reserved.