ISARA ATRP of methacrylic acid neutralized by simple amines yielding linear polymers and anionic molecular brushes

Abstract

ISARA ATRP of the neutralized methacrylic acid (MAA) initiated by low-molecular ATRP initiator or a polymer bearing multiple ATRP initiating groups is reported demonstrating successful synthesis of linear polymers and anionic molecular brushes. To make suitable for polymerization by ATRP and solubilize in common organic solvents, methacrylic acid (MAA) was neutralized by simple amines ethylamine (MEA), diethylamine (DEA) or triethylamine (TEA). It was shown by cyclic voltammetry measurements that only TEA was proper neutralizing amine did not affecting or minimally affecting stability of the catalyst CuII/Me6TREN and enabling to carry out controlled polymerization of MAA by ATRP. ISARA ATRP of MAA neutralized by TEA was slow but well controllable enabling to synthesize PMAA with low polydispersity (PDI 1.10–1.25). ISARA ATRP of the neutralized MAA from the polymethacrylate-type backbone carrying multiple ATRP initiating groups resulted in graft copolymers with short to medium-length side chains of PMAA (DP up to 65). As determined by SEC with triple detection, anionic molecular brushes were characterized by unimodal MWD and reasonably low polydispersity index (Mw/Mn 1.2–1.4).