Solution Polymerization of Methyl Methacrylate in an Ionic Liquid Employing Cyclic Multifunctional Initiators

Abstract

1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) was used as a solvent during the methyl methacrylate polymerization, in a temperature range of 110 to 130°C, employing two multifunctional cyclic peroxides as initiators, the pinacolone diperoxide and the diethylketone triperoxide, and results were compared with those obtained in N,N-dimethylformamide (DMF) as a solvent under the same reaction conditions. The polymerization rate was approximately four times faster in [BMIM][BF4] than in DMF, and this behavior is supported by the higher decomposition rate constants calculated for both initiators in pure ionic liquid in comparison with those calculated in DMF. The average molecular weights values were nearly three times lower in DMF than in the ionic liquid, and this is explained by the reduction in the propagation activation energy in the presence of the ionic liquid.