In this study, new anion exchange membranes (AEM) based on crosslinked polybenzimidazole (m-PBI) with quaternary ammonium groups, crosslinkable allyl groups, and hydrophobic ethyl groups as side chains are synthesized and characterized. The AEMs are crosslinked by thermal thiol-ene reaction using a dithiol crosslinker. The ion exchange capacity (IEC) values and crosslinking density were controlled by the number of quaternary ammonium groups and allyl groups, respectively. The introduction of ethyl groups improved the solubility of ionic PBIs even at very low IEC values by eliminating the hydrogen bonding interaction of imidazole rings. This method allows ionic PBIs with broad IEC values, from 0.75 to 2.55 mmol/g, to be prepared. The broad IEC values were achieved by independently controlling the numbers of quaternary ammonium groups, allyl groups, and hydrophobic ethyl groups during preparation. The crosslinked ionic PBIs revealed hydroxide conductivity from 16 to 86 mS/cm at 80°C. The wet membranes also showed excellent mechanical strength with tensile strength of 12.2 to 20.1 MPa and Young's Modulus of 0.67 to 1.45 GPa. The hydroxide conductivity of a crosslinked membrane (0.40Q0.60Et1.00Pr, IEC = 0.95 mmol/g) decreased only 7.9% after the membranes was immersed in a 1.0 M sodium hydroxide solution at 80°C for 720 h. A single fuel cell based on this membrane showed a maximum peak power density of 136 mW/cm² with a current density of 377 mA /cm² at 60°C.

中文翻译：

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用于阴离子交换膜燃料电池应用的具有广泛离子交换容量范围的离子聚苯并咪唑的合成

在这项研究中，基于交联聚苯并咪唑 ( m ) 的新型阴离子交换膜 (AEM)-PBI) 以季铵基团、可交联的烯丙基和疏水性乙基作为侧链被合成并表征。AEM 使用二硫醇交联剂通过热硫醇-烯反应交联。离子交换容量 (IEC) 值和交联密度分别由季铵基团和烯丙基的数量控制。通过消除咪唑环的氢键相互作用，即使在非常低的 IEC 值下，乙基的引入也提高了离子 PBI 的溶解度。该方法允许制备具有宽 IEC 值（0.75 至 2.55 mmol/g）的离子 PBI。广泛的 IEC 值是通过在制备过程中独立控制季铵基团、烯丙基和疏水乙基基团的数量来实现的。交联的离子 PBIs 在 80°C 下显示氢氧化物电导率为 16 至 86 mS/cm。湿膜还表现出优异的机械强度，拉伸强度为 12.2 至 20.1 MPa，杨氏模量为 0.67 至 1.45 GPa。在将膜浸入 80°C 的 1.0 M 氢氧化钠溶液中 720 小时后，交联膜的氢氧化物电导率（0.40Q0.60Et1.00Pr，IEC = 0.95 mmol/g）仅降低了 7.9%。基于该膜的单个燃料电池的最大峰值功率密度为 136 mW/cm 将膜浸入 80°C 的 1.0 M 氢氧化钠溶液中 720 小时后，浓度为 9%。基于该膜的单个燃料电池的最大峰值功率密度为 136 mW/cm 将膜浸入 80°C 的 1.0 M 氢氧化钠溶液中 720 小时后，浓度为 9%。基于该膜的单个燃料电池的最大峰值功率密度为 136 mW/cm²在 60°C 下具有 377 mA /cm ²的电流密度。