Atom Transfer Polymerization of Methyl Methacrylate. Effect of Acids and Effect with 2-Bromo-2-Methylpropionic Acid Initiation

Synthesis of polymers with well-controlled architecture and predictable molecular weight is currently of great academic and industrial interest. Transition metal mediated atom transfer polymerization (ATP) has emerged as an effective living/controlled method for the polymerization of styrenes, methacrylates, acrylates, and acrylonitrile. Although the mechanism is not yet fully established, the current belief is that a halogen atom is abstracted, either fully or partially, in a homolytic bond cleavage from either an alkyl halide or sulfonyl halide by a transition metal complex. The aim of the work described here was 2-fold: first, to investigate the use of 2-bromo-2-methylpropionic acid, 1, as an initiator for the ATP of MMA to produce carboxyl-functionalized PMMA and second, to investigate the effect of carboxylic acids on ATP initiated by a nonfunctional alkyl halide in conjunction with copper(I) N-n-alkyl-2-pyridylmethanimine complexes.