کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5188511 | 1381158 | 2007 | 5 صفحه PDF | دانلود رایگان |
A series of sulfonated polyimides (SPIs) were synthesized in m-cresol from 4,4â²-binaphthyl-1,1â²,8,8â²-tetracarboxylic dianhydride (BNTDA), 4,4â²-diaminodiphenylether-2,2-disulfonicacid (ODADS), and 4,4â²-diamino-diphenyl ether (ODA) in the presence of triethylamine and benzoic acid. The resulted polyimides showed much better water resistance than the corresponding sulfonated polyimides from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) and ODADS, which is contributed to the higher electron density in the carbonyl carbon atoms of BNTDA. Copolyimides S-75 and S-50 maintained their mechanical properties and proton conductivities after aging in water at 100 °C for 800 h. The proton conductivity of these SPIs was 0.0250-0.3565 S/cm at 20 °C and 100% relative humidity (RH), and increased to 0.1149-0.9470 S/cm at 80 °C and 100% RH. The methanol permeability values of these SPIs were in the range of 0.99-2.36 Ã 10â7 cm2/s, which are much lower than that of Nafion 117 (2 Ã 10â6 cm2/s).
Journal: Polymer - Volume 48, Issue 21, 5 October 2007, Pages 6210-6214