Attributed to their perfluorinated backbone, perfluoroalkyl sulfonic acid (PFSA) proton exchange membranes (PEMs) exhibit both excellent stability and high performance. However, the high cost and increasing regulations on perfluoroalkyl compounds raising the demand for hydrocarbon-based PEMs. For now, most reported hydrocarbon-based PEMs are synthesized through condensation polymerization, which leads to chemical disorder, thereby reducing the overall proton conductivity of the fuel cell.
In this study, we present a block-copolymer-based proton exchange membrane synthesized via RAFT polymerization, enabling precise control over membrane properties such as molecular weight or degree of sulfonation. Styrene-based monomers are employed to enhance chemical stability, and sulfonic acid groups are introduced through facile post-polymerization modification. The synthesized membrane exhibited proton conductivity and fuel cell performance comparable to those of the Nafion membrane.