Studies of sulfonated polyphenylene membranes containing benzophenone moiety for PEMFC

The sulfonated polyphenylenes containing benzophenone structure (sulfonated Parmax 1200, S-Parmax) were prepared by sulfonation reaction of Parmax 1200 with 30% fuming sulfuric acid, and degree of sulfonation was controlled by sulfonation reaction time. These polymers have all carbon structure without ether linkages that have the possibility of attack by nucleophiles (made by PEMFC operating system). The polyphenylene structure of Parmax provides a stiff and resistant backbone, whereas the pendant benzoyl group enables the solubility of the material, and also provides sites for chemical modifications. The structure properties of the synthesized polymers were investigated by 1H NMR spectroscopy. The membranes were studied by ion exchange capacity (IEC), water uptake, and proton conductivity. These membranes deterioration test was performed by Fenton reagent, and compared with normal sulfonated poly(ether sulfone)s and Nafion. The power densities of membranes were performed by single cell.