RAFT-mediated polymerization-induced self-assembly of poly(ionic liquid) block copolymers in a green solvent

Here, we report a novel method for regulating the morphology of block copolymer assemblies through the use of reversible addition-fragmentation chain transfer dispersion polymerization in ethanol. In this method, poly(N,N-dimethylacrylamide) is used as a macromolecular chain transfer agent, and the side chain length of the ionic liquid monomer is modified. A notable change in the morphology of the alkyl-imidazole monomer (1-alkyl-3-(4-vinylbenzyl) imidazolium tetrafluoroborate) was observed when the side chain length was modified from methyl to butyl. This phenomenon can be attributed to a structural change in the alkyl imidazole monomers, which resulted in enhanced solvent-phobic properties. The polymerization kinetics and glass transition temperatures of the block polymers were investigated. These results demonstrated that the polymerization rate increased with increasing number of side chains, whereas the glass transition temperature of the block polymers decreased. It provides a novel approach for the synthesis and utilization of poly(ionic liquid) block polymers with higher-order morphologies.