Abstract
Three brønsted acidic ionic liquids, 1-methylimidazolium acetate ([Hmim][CH3COO]), 1-methylimidazolium propionate ([Hmim][CH3CH2COO]) and 1-methylimidazolium butyrate ([Hmim][CH3CH2CH2COO]) were used as reaction medium for atom transfer radical polymerization of methyl methacrylate with ethyl 2-bromoisobutyrate (EBiB)/CuBr as the initiating system. Kinetic studies, chain extension and block copolymerization confirmed the well-controlled manner of these polymerizations in three brønsted acidic ionic liquids. The reactions were fast and the polydispersities of the polymers were quite narrow (1.10<Mw/Mn<1.34). The rate of polymerization in [Hmim][RCOO] decreased with the increasing alkyl chain lengths (n from 1 to 3), indicating a strong dependence of reaction rate on the length of the substituted groups of the anions in ionic liquids.