کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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635288 | 1456092 | 2012 | 8 صفحه PDF | دانلود رایگان |

In this work, we synthesize two poly(benzimidazole) (PBIs), i.e., medium molecular weight PBIm and high molecular weight PBIh with 〈Mw〉 = 9.16 × 104 and 1.60 × 105 g/mol, respectively, and two butylsulfonate grafted PBIs (PBI-BSs), i.e., PBIm-BS and PBIh-BS. In the PBIs, 22 mole% of imidazole groups of PBIm and 17 mole% of imidazole groups of PBIh are grafted with butyl sulfonate groups. The PBIh/PBIh-BS and PBIm/PBIm-BS blend membranes are prepared with various weight (wt) ratios of PBI/PBI-BS. We demonstrate that PBIh/PBIh-BS blend membranes have better mechanical properties, phosphoric acid doping level, proton conductivity, and fuel cell performance than neat PBI and PBIm/PBIm-BS blend membranes. The influences of PBI molecular weight and the Lewis acid–base interaction of PBI-BS butyl sulfonic acids with imidazole groups on the membrane properties and fuel cell performances of PBI/PBI-BS blends are discussed.
► Two PBIs, with 〈Mw〉 = 9.16 × 104 (PBIh) and 1.60 × 105 g/mol (PBIm), were synthesized.
► Two butylsulfonate grafted PBIs, PBIm-BS (with 22 mole%) and PBIh-BS (with 17 mole%), were synthesized.
► The PBIh/PBIh-BS membranes have better fuel cell performance than PBI and PBIm/PBIm-BS membranes.
► Three factors control the membrane properties, namely: hydrogen bonds, acid–base interactions, and excess free volume.
Journal: Journal of Membrane Science - Volume 389, 1 February 2012, Pages 399–406