Preparation and Characterization of Phosphoric Acid Doped Polyacrylamide/β‐Cyclodextrin High‐Temperature Proton Exchange Membrane

Abstract The development of high‐temperature proton exchange membrane fuel cells calls for better membrane, and a polyacrylamide/ β ‐cyclodextrin hydrogel proton exchange membrane is prepared by solution polymerization of β ‐cyclodextrin ( β ‐CD) and acrylamide (Am), for which ammonium persulfate (APS) and N, N ″‐(methylene)bisacrylamide (MBA) is used as initiator and crosslinking agent, respectively. The observed proton conductivity of the membrane reaches 12.3 S m −1 at room temperature, when the ratio of β‐CD , APS, MBA to Am monomer is 0.42 mol%, 0.37 mol%, and 0.14 mol%, respectively, and the primary concentration of doped phosphoric acid is 8 mol L −1 . The observed proton conductivity evolution on temperature obeys Arrhenius' law, indicating that the proton conduction mainly follows the hopping mechanism. In addition, the prepared PAM/ β ‐CD proton exchange membrane has a mass loss of only 8.47% at 205 °C, showing good thermal stability compared with PBI membrane. It also has good antioxidative stability as well as promising potential application in high‐temperature fuel cells.