LIGATED ANIONIC BLOCK COPOLYMERIZATION OF METHYL-METHACRYLATE WITH N-BUTYL ACRYLATE AND N-NONYL ACRYLATE AS PROMOTED BY LITHIUM 2-(2-METHOXYETHOXY) ETHOXIDE DIPHENYLMETHYLLITHIUM

Poly(methyl methacrylate-b-n-butyl acrylate) (PMMA-b-Pn-BuA) and poly( methyl methacrylate-b-n-nonyl acrylate) (PMMA-b-Pn-NonA) diblock copol ymers have been successfully synthesized by the sequential anionic pol ymerization of methyl methacrylate (MMA) and the n-alkyl acrylate (n-B uA or n-NonA), in a 90/10 toluene/tetrahydrofuran (THF) mixture at -78 degrees C. When diphenylmethyllithium (DPMLi) ligated with lithium 2- (2-methoxyethoxy) ethoxide (LiOEEM) is used as the initiator, the poly merization of each block appears to be living. Molecular weight and co mposition of block copolymers can be predicted from the monomer over i nitiator molar ratio and the molecular weight distribution is narrow. Size exclusion chromatography (SEC) supports that no homo-PMMA contami nates the final copolymer. Although the reverse polymerization sequenc e Pn-NonA-b-PMMA always results in some contamination by homo-Pn-NonA, it has no really significant effect on the final product characterist ics. (C) 1997 John Wiley & Sons, Inc.