(304c) Synthesis and Properties of a Multiblock Copolymer for Anion Exchange Membrane Fuel Cells

Anionic fuel cells are a possible route to overcoming fundamental issues with acid-based fuel cells. The issues include the high cost of platinum catalysts, complex water transport, and sluggish electrochemical reactions. In particular, a bipolar membrane composed of a cation conducting material and an anion conducting material has several additional advantages because each electrode can have an optimum pH, and water can be created at the cation/anion membrane interface close to where it is used at the air cathode.

A novel multiblock copoly(arylene ether) with long side chains was synthesized for anion exchange membrane (AEM) fuel cells. The multiblock copolymers were synthesized by polycondensation of separately-prepared hydroxyl-terminated oligomers with fluoro-terminated oligomers. The resulting multiblock structure, in which one block is hydrophilic and one block is hydrophobic, was designed to ensure a nanophase-separated morphology. Copolymers with long side chains exhibited higher stability in high pH environment than their counterparts without long side chains. Furthermore, multiblock copolymers with different block lengths and ion exchange capacities (IEC) were synthesized to maximize ion conductivity and explore the relationship between chemical structures and properties in anion exchange membranes.