Facile synthesis and catalytic activity of welldefined amphiphilic block copolymers based on N-vinylimidazolium

摘要

Well-defined amphiphilic block copolymers, poly(styrene)-b-poly(N-vinylimidazole) (PS-b-PVim), were successfully synthesized by macromolecular design via interchange of the xanthates/reversible addition-fragmentation chain transfer (RAFT) polymerization. The structure of the copolymer based on Vim can be well controlled, and the molecular weight distribution was relatively narrow (PDI = 1.24). The size and morphology of the aggregates of the amphiphilic copolymers were investigated by dynamic light scattering and transmission electron microscope, the results implied that the uniform spheroidal micelles consisting of PS core and PVim corona were assembled, and the catalytic activities of PS-b-PVim for the hydrolysis of p-nitrophenyl acetate at different temperatures were also investigated by high-performance liquid chromatograph (HPLC); the catalytic activities of diblock copolymers were prominently improved compared with that of PVim homopolymers. Moreover, the catalytic activities of the copolymers followed the Arrhenius behavior in the wide experimental temperature range.