کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1286169 | 973179 | 2007 | 9 صفحه PDF | دانلود رایگان |
A series of novel oxidation and water stable sulfonated polyimides (SPIs) were synthesized from 4,4′-binaphthyl-1,1′,8,8′-tetracarboxylic dianhydride (BTDA), and wholly aromatic diamine 2,2′-bis(3-sulfobenzoyl) benzidine (2,2′-BSBB) for proton exchange membrane fuel cells. These polyimides could be cast into flexible and tough membranes from m-cresol solutions. The copolymer membranes exhibited excellent oxidative stability and mechanical properties due to their fully aromatic structure extending through the backbone and pendant groups. Moreover, all BTDA-based SPI membranes exhibited much better water stability than those based on the conventional 1,4,5,8-naphthalenecarboxylic dianhydride. The improved water stability of BTDA-based polyimides was attributed to its unique binaphthalimide structure. The SPI membranes with ion exchange capacity (IEC) of 1.36–1.90 mequiv g−1 had proton conductivity in the range of 0.41 × 10−1 to 1.12 × 10−1 S cm−1 at 20 °C. The membrane with IEC value of 1.90 mequiv g−1 displayed reasonably higher proton conductivity than Nafion® 117 (0.9 × 10−1 S cm−1) under the same test condition and the high conductivity of 0.184 S cm−1 was obtained at 80 °C. Microscopic analyses revealed that well-dispersed hydrophilic domains contribute to better proton conducting properties. These results showed that the synthesized materials might have the potential to be applied as the proton exchange membranes for PEMFCs.
Journal: Journal of Power Sources - Volume 172, Issue 2, 25 October 2007, Pages 511–519