Reverse atom transfer radical polymerization of methyl methacrylate in imidazolium ionic liquids

Abstract

Reverse atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) employing 2,2-azobisisobutyronitrile (AIBN)/CuCl 2/bipyridine(bipy) as the initiating system was approached at 80 °C in two ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([C 4mim][BF 4]) and 1-dodecyl-3-methylimidazolium tetrafluoroborate ([C 12mim][BF 4]), respectively. The polymerization in [C 12mim][BF 4] proceeded in a well-controlled manner as evidenced by kinetic studies, end group analysis, chain extension, and block copolymerization results, but not in [C 4mim][BF 4] presumably due to poor solubility of PMMA in it. The kinetic study of reverse ATRP of MMA in recycled [C 12mim][BF 4] suggested that this ionic liquid could be re-used as reaction solvent after simple purification, without affecting the living nature of polymerization.