| 초록 |
Cross-linked poly(2,5-benzimidazole) (C-ABPBI) membranes based on wholly aromatic groups were prepared via a reaction between three-arm poly(2,5-benzimidazole)s with carboxylic acid end groups (T-ABPBI) and 3,3’-diaminobenzidine (DABI) in poly(phosphoric acid) (PPA) during the casting process. T-ABPBI was synthesized by the polymerization of 3,4-diaminobenzoic acid, followed by the reaction with 1,3,5-benzenetricarboxylic acid in PPA. The cross-linking process improved the chemical and thermal stability of the host polymer. The C-ABPBI membranes could contain a higher phosphoric acid (PA) content than the membranes consisting of linear polybezimidazoles, such as ABPBI and poly[2,2’-(m-phenylene)-5,5’-bibenzimidazole]. Consequently, the C-ABPBI membranes showed higher proton conductivity values than the linear membranes. For example, the C-ABPBI-50 membrane could contain a PA content above 84 wt % with a proton conductivity of 0.12 S cm-1 at 150 oC under anhydrous conditions. |
