Ultrafast and green ionic liquid-mediated controlled cationic polymerization towards amphiphilic diblock copolymers

Abstract

Ionic liquids (ILs) have gained a lot of interest in recent years for use as solvents in organic transformation/polymerization reactions. However, gaining control over ambient temperature polymerization would expand the use of ILs and facilitate the design of new polymer architectures using a green synthetic strategy. We report, herein, an unprecedented level of control in the IL-mediated ambient temperature controlled cationic polymerization of styrene (St), yielding well-defined PSt and polystyrene-b-poly(isobutyl vinyl ether) (PSt-b-PIBVE) diblock copolymers with acceptable dispersity values (Đ ≤ 1.21), demonstrating high chain-end fidelity. The hydrolysis of PIBVE segments of the PSt-b-PIBVE diblock copolymers leads to the synthesis of amphiphilic polystyrene-b-poly(vinyl alcohol) diblock copolymers, which self-assemble into spherical nanospheres in solution. DFT calculations rationalize the proposed mechanism of this polymerization.