Fluorinated-sulfonated polyaryl ether block copolymer/polyethylene composite membranes for fuel cell applications

摘要

In this study, five fluorinated-sulfonated poly (arylene ether sulfone) (FS-PAES) block copolymers containing perfluorocyclobutane (PFCB) - were prepared via three synthetic steps; the trifluorovinyloxy end-capped biphenylene [sulfonable at room temperature] monomer and sulfonyl biphenylene [non-sulfonable at room temperature] monomer were first prepared. Secondly, sulfonatable biphenylene monomers were heated to form oligomer blocks [MW: 13,000] and then, non-sulfonable sulfonyl monomer were added to give the PAES block copolymers. Finally, the FS-PAES were obtained via post-sulfonation using chlorosulfonic acid at room temperature. The electrochemical properties- ion exchange capacity (IEC), water uptake, and ion conductivity- of FS-PAES block copolymers were evaluated. The composite membranes were prepared using FS-PAES block copolymer and porous polyethylene [PE] film. Membrane and electrode assembly (MEA)s were made with the composite membranes and tested for DMFC and PEMFC applications. It was confirmed the FS-PAES block copolymer /PE composite membranes could be an alternative to Nafion-115 membranes.