Zhaoxia Hu, Yan Yin, H. Kita
Mar 23, 2007
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Influential Citations
62
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Journal
Polymer
Abstract
Abstract A novel sulfonated diamine bearing sulfophenyl pendant groups of 2,2′-(4-sulfophenyl) benzidine (BSPhB) was synthesized. Sulfonated polyimides (SPIs) derived from 1,4,5,8-naphthalene tetracarboxylic dianhydride, BSPhB and other non-sulfonated diamines were successfully synthesized. The SPIs with ion exchange capacity (IEC) of 1.5–2.8 meq g −1 showed high reduced viscosity of 3–10 dL g −1 and high desulfonation temperature of 320 °C. The SPI membranes were tough and flexible, having high stress at break of more than 80 MPa and elongation of 80–100%. They showed highly anisotropic membrane swelling in water with larger swelling in thickness direction than in plane direction. They showed fairly high proton conductivity ( σ ). For example, the membrane with IEC of 1.77 meq g −1 exhibited σ values of 120 and 260 mS cm −1 at 60 and 120 °C, respectively, in water. They also showed fairly high water stability.