Group transfer polymerization by bifunctional initiators : a simple method for ABA tri-block copolymers

Abstract

"Living" polymerization of methacrylates and acrylates was achieved over a broad range of polymerization temperatures by using bifunctional initiators in the presence of bifluoride catalysts. The copolymerization of various acrylic monomers with new bifunctional initiators and catalysts was studied. Bifunctional initiators, [1,6-Dimethoxy-2,5-dimethyl-1,5-hexadiene-1,6- diylbis(oxy)]bis[trimethylsilane] and [1,5-Dimethoxy-2,4-dimethyl-1,4- pentadiene-1,5-diylbis(oxy)]bis[trimethylsilane], were presented by silylation of the dianions of corresponding esters. ABA tri-block copolymers were prepared from methyl methacrylate(MMA) and butyl methacrylate(BMA); MMA and allyl methacrylate(AMA): MMA and methyl acrylate(MA); MMA and acrylonitrile(AN); MMA and 2-hydroxyethyl methacrylate(HEMA).