کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5189701 | 1381190 | 2007 | 9 صفحه PDF | دانلود رایگان |
A novel sulfonated polybenzimidazole, sulfonated poly[2,2â²-(p-oxydiphenylene)-5,5â²-bibenzimidazole] (SOPBI), was successfully prepared by post-sulfonation reaction of the parent polymer, poly[2,2â²-(p-oxydiphenylene)-5,5â²-bibenzimidazole] (OPBI), using concentrated and fuming sulfuric acid as the sulfonating reagent at 80 °C, and the degree of sulfonation (DS) could be regulated by controlling the reaction conditions. No significant polymer degradation was observed in the post-sulfonation processes. Direct polymerization of 4,4â²-dicarboxydiphenyl ether-2,2â²-disulfonic acid disodium salt (DCDPEDS) and 3,3â²-diaminobenzidine (DABz), however, resulted in insoluble gels either in polyphosphoric acid (PPA) or in phosphorus pentoxide/methanesulfonic acid (PPMA) in a ratio of 1:10 by weight reaction medium. The SOPBIs prepared by the post-sulfonation method showed good solubility in dimethyl sulfoxide (DMSO), high thermal stability, good film forming ability and excellent mechanical properties. Cross-linked SOPBI membranes were successfully prepared by thermal treatment of phosphoric acid-doped SOPBI membranes at 180 °C in vacuo for 20 h and the resulting cross-linked membranes showed much improved water stability and radical oxidative stability in comparison with the corresponding uncross-linked ones, while the proton conductivity did not change largely. Highly proton conductive (150 mS cmâ1, 120 °C in water) and water stable SOPBI membrane was developed.
Journal: Polymer - Volume 48, Issue 19, 10 September 2007, Pages 5556-5564