One-step hybrid block copolymerization by organocatalysis

Abstract

Hybrid block copolymers, comprising two or more polymer segments with distinct main-chain compositions and physicochemical properties, have garnered profound interests due to their often-fortified propensities for self-assembly and microphase separation. An ideal approach for synthesizing such a block copolymer comprises spontaneously sequential or simultaneous polymerizations of mixed monomers, bearing different polymerizable groups, from one initiator. However, major challenges are frequently posed by the stringent requirements for dual catalyst-monomer suitability and/or the compatibility of two mechanistically distinct polymerizations. Fortunately, recent years have witnessed rapid progress in organo-/metal-free catalytic polymerization techniques, cultivating a diversity of effective strategies for achieving sequence-selective copolymerization of mixed monomers and one-step controlled synthesis of hybrid block copolymers. We aim to summarize here the recent advances in one-step block copolymerization of heterocycles by organocatalysis, with also vinyl monomers involved in plenty of cases. We also provide a brief overview of the critical reaction mechanisms, address current limitations, and suggest future directions for one-step block copolymer synthesis.