Polymer electrolyte fuel cells (PEFC) membranes based on very thin film of network polytetrafluoroethylene (PTFE)/tetrafluoroethylene-co-hexafluoropropylene (FEP) polymer-alloy (PTFE/FEP polymer-alloy: FE), have been fabricated by radiation-grafting with reactive styrene monomers using electron beam irradiation (EB) under nitrogen atmosphere at room temperature. The characteristic properties of obtained materials have been measured by ion exchange capacity (IEC), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and so on. The grafting yields showed the initial rapid increase, and then tended to saturate above 5-8 h. The grafting yields of all FE with various network densities have been achieved 80-100%. The styrene-grafted materials were sulfonated by chlorosulfonic acid. The IECs of sulfonated materials based on FE polymer-alloy have been achieved 3.0 meq/g. This suggests that IEC value is independent on network density and PTFE/FEP blend ratio. The IEC values of obtained materials are about three times higher than those of commercial perfluoro-sulfonic acid (PFSA) membranes. By small angle X-ray scattering (SAXS), it is found that the higher network densities would give the smaller cluster sizes in sulfonated materials. Thus, the higher amount of FEP will give the smaller cluster formation of sulfonated materials.
|Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
|Published - 2005 7月
|Ionizing Radiation and Polymers Proceedings of the 6th International Symposium on Ionizing Radiation Polymers -
継続期間: 2004 9月 25 → 2004 9月 30
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