Modular Synthesis of Functional Block Copolymers by Thiol–Maleimide “Click” Chemistry for Porous Membrane Formation

Abstract

In this work, a modular strategy for the synthesis of block copolymers (BCPs) is presented using the quantitative reaction of a maleimide with a thiol. For this purpose, anionic polymerization and atom transfer radical polymerization were used to generate end-functionalized homopolymers. For proof of concept, polystyrene-b-poly(2-hydroxyethyl methacrylate) (PS-bPHEMA) BCPs with different molecular weights and segment ratios were synthesized, leading to high molecular weights of 128 kg mol−1 with a polydispersity index of 1.18. Additionally, the synthesis of polystyrene-b-poly(2-aminoethyl methacrylate) and polystyrene-b-poly(2-hydroxyethyl methacrylate)-b-poly(2,2,2-trifluoroethyl methacrylate) terpolymer was investigated. The access of PS-b-PHEMA to isoporous integral membranes by the self-assembly and non-solvent-induced phase separation (SNIPS) process was confirmed by scanning electron microscopy. The produced SNIPS membranes featured a maximum water flux of 608 L bar−1 h−1 m−2 and a maximum transmembrane pressure of 2.7 bar. This modular synthesis system demonstrates the utility of scalable SNIPS membrane formation for biomedical and water filtration applications.