Characterization of a soluble poly(ether ether ketone) anion exchange membrane for fuel cell application

• We synthesized PEEK with quaternary ammonium hydroxide groups.
• We evaluate the performance of the membrane with different mole ratios.
• The IEC value of the membrane increased with increasing ammonium moiety.

In this study, we synthesized a novel poly(ether-ether-ketone), containing di(quaternary ammonium) hydroxide groups in the polymer chain. Then we tested the alkaline–exchange properties of a membrane made from the novel polymer, for fuel-cell applications. First, we synthesized a di-hydroxide monomer with amine groups, which were then converted to ammonium functional groups by immersion in hydroxide solution. Then, we synthesized poly(ether-ether-ketone) using a synthesized monomer and bisphenol A. We controlled the mole ratio of the quaternary ammonium hydroxide groups in the polymer structure to evaluate the performance of the membrane. The performances of polymer-electrolyte membranes with differing degrees of amination were compared. The optimum composition of the membrane was determined based on the chemical and thermogravimetric analyses, mechanical properties, the behavior of water in the membrane, and the level of ion conductivity.