Chapter 12
Downloaded by OHIO STATE UNIV LIBRARIES on May 31, 2012 | http://pubs.acs.org Publication Date (Web): May 7, 2012 | doi: 10.1021/bk-2012-1096.ch012
Cross-Linked Low EW PFSA for High Temperature Fuel Cell H. Ghassemi,*,a T. Zawodzinski,b D. Schiraldi,a and S. Hamrockc aDepartment
of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106 bDepartment of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37996 c3M Fuel Cell Components Program, 3M Company, St. Paul, Minnesota 55144 *email:
[email protected] Several approaches have been studied to prepare ionomers for a high temperature proton exchange membrane (PEM) fuel cell. These ionomers were designed to be very low equivalent weight (EW), chemically stable, solvent resistant and highly conductive. The synthetic approaches include grafting, hybrid formation and cross-linking. The most interesting results were obtained from cross-linking of functionalized PFSA ionomers with various cross-linking compounds. New side-chain component multifunctional ionomers have been developed that were cross-linkable during or after membrane fabrication. As a result of this approach, a suite of polymers have been synthesized that, after membrane casting and cross linking show improved solvent resistant, low swelling and excellent proton conductivity. An obvious approach to increase proton conductivity in PSFA materials is to lower the equivalent weight (EW) by increasing the number of protogenic groups. PFSA membranes with EW < 700 g/mol show conductivity of ca 0.1 S/cm at 120°C and
