WO200291507-A1  See also references of EP 1394879A1EP1394879-A1  See also references of WO 02091507A1US7258941-B2  B. Baradie et al., "Water Sorption and Protonic Conductivity in a Filled/Unfilled Thermostable Ionomer for Proton Exchange Membrane Fuel Cell," Macromol. Symp., V. 138, 1999, pp. 85-91.;  Emily J. Stoler et al., "Stabilization of High Temperature PEM Fuel Cell Membranes," Proceedings of 36th IECE Conference, 2001, pp. 975-980.;  Feng Wang et al., "Direct Polymerization of Sulfonated Poly(arylene ether sulfone) Random (Statistical) Copolymers: Candidates for New Proton Exchange Membranes," Journal of Membrane Science, V. 197, 2002, pp. 231-242.;  Feng Wang et al., "Sodium Sulfonated-Functionalized Poly(Ether Ether Ketone)s," Macromol. Chem. Phys., V. 199, 1998, pp. 1421-1426.;  J. Kerres et al., "Preparation, Characterization and Fuel Cell Application of New Acid-Base Blend Membranes," Journal of New Materials for Electrochemical Systems, V. 3, 2000, pp. 229-239.;  Jochen A. Kerres, "Development of Ionomer Membranes for Fuel Cells," Journal of Membrane Science, V. 185, 2001, pp. 3-27.;  Jochen Kerres et al., "Development and Characterization of Crosslinked Ionomer Membranes Based upon Sulfinated and Sulfonated PSU Crosslinked PSU Blend Membranes by Disproportionation of Sulfinic Acid Groups," Journal of Membrane Science, V. 139, 1998, pp. 211-225.;  M. Walker et al., "Proton-Conducting Polymers with Reduced Methanol Permeation," Journal of Applied Polymer Science, V. 74, 1999, pp. 67-73.;  Mitsuru Ueda et al., "Synthesis and Characterization of Aromatic Poly(ether Sulfone)s Containing Pendant Sodium Sulfonate Groups," Journal of Polymer Science: Part A: Polymer Chemistry, V. 31, 1993, pp. 853-858.;  P. Genova-Dimitrova et al., "Ionomeric Membranes for Proton Exchange Membrane Fuel Cell (PEMFC): Sulfonated Polysulfone Associated with Phosphatoantimonic Acid," Journal of Membrane Science, V. 185, 2001, pp. 59-71.;  R. Nolte et al., "Modified Polysulfones as Membrane Electrolytes," BHR Group Conf. Ser. Publ, V. 3, 1993, p. 381-385.;  R. Nolte et al., "Partially Sulfonated Poly (Arylene Ether Sulfone) -A Versatile Proton Conducting Membrane Material for Modern Energy Conversion Technologies," Journal of Membrane Science, V. 83, 1993, pp. 211-220.;  R.N. Johnson et al., "Poly(aryl Ethers) by Nucleophilic Aromatic Substitution. I. Synthesis and Properties," Journal of Polymer Science, V. 5, 1967, pp. 2375-2398.;  Shiao-Ping "Elizabeth" Yen et al., "Low Cost Membranes for PEM Fuel Cells," Proc. Power Sources Conf., 38th, 1998, pp. 469-472.;  Yu Seung Kim et al., "Heteropolyacid/Sulfonated Poly(arylene (ether sulfone) Composites for Proton Exchange Membrandes Fuel Cells," Polymeric Materials: Science & Engineering, V. 85, 2001, pp. 520-521.;  Zhonggang Wang et al., "Synthesis and Properties of Novel Random and Block Copolymers Composed of Phthalimidine- and Perfluoroisopropylidene-Polyarylether-Sulfones," Polymer International, V. 50, 2001, pp. 249-255.;  Zhongwen Wu et al., "Molecular Aggregation of PEEK with PES Blends and the Block Copolymers Composed of PEEK and PES Compounds," Die Angewandte Makromolekulare Chemie, V. 173, 1989, pp. 163-181.