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Indexed by:期刊论文

Date of Publication:2012-12-15

Journal:JOURNAL OF MEMBRANE SCIENCE

Included Journals:SCIE、Scopus

Volume:423

Page Number:128-135

ISSN No.:0376-7388

Key Words:Polybenzimidazole; Phthalazinone; Soluble; Acid doped; Proton exchange membrane

Abstract:A novel series of polybenzimidazoles containing 4-phenyl phthalazinone moieties and p-phenylene linkages (p-PPBI) were synthesized from 4-(4-(4-(4-carboxyphenoxy)phenyl)-1-oxophthalazin-2(1H)-yl)benzoic acid (CPPBC), terephthalic acid (TPA) and 3,3'-diaminobenzidine (DAB) in polyphosphoric acid (PPA). The chemical structures of p-PPBI polymers were characterized by FT-IR, H-1 NMR, C-13 NMR and WAXD. The resultant polymers have inherent viscosities from 1.78 to 3.43 dL/g in 96% sulfuric acid at 30 degrees C and show good solubility in aprotic polar solvents, such as N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and dimethyl sulfoxide (DMSO). These p-PPBI polymers exhibit high glass transition temperatures (T-g) in the range of 399-426 degrees C and excellent thermal stability with the 5% (T-d5%) and 10% (T-d10%) weight loss temperatures in the range of 516 to 594 degrees C and 560 to 672 degrees C, respectively. These amorphous polymers were cast into membranes and further investigated as proton exchange membranes. Membranes with high acid doping level (similar to 15.2 mol H3PO4) and high proton conductivity (similar to 0.13 S/cm) were obtained after doping with phosphoric acid. These obtained membranes present good oxidative stability and mechanical property even with high doping levels. The p-PPBI polymers are promising candidates for high-temperature proton exchange membranes. (c) 2012 Elsevier B.V. All rights reserved.