60Co γ-irradiation initiated polymerization in ionic liquids - The effect of carbon-chain length of monomer

Gamma-radiation initiated polymerization of Methyl methacrylate (MMA) and Butyl methacrylate (BMA) was carried out in room temperature ionic liquid (RTIL) [Me3NC2H4OH]+ [ZnCl3]− and RTIL/organic solutions. MMA and BMA were selected as the represents of vinyl monomers in order to understand the effect of side-chain carbon length on properties of the resulting polymer. Although both PMMA and PBMA from RTIL/organic solution at high RTIL content have significantly higher molecular weight than those at RTIL 20 vol.%, their molecular weight distributions (MWDs) are clearly different. For polymerization in RTIL/THF and RTIL/MeOH solutions, PMMA has a single-modal MWD while PBMA has a multi-modal MWD. This difference is probably due to the better compatibility of PMMA with RTIL/THF and RTIL/MeOH solutions, though PMMA is insoluble in pure methanol.