Abstract

Ion segregation is critically important for achieving high ion conductivity for anion exchange membranes (AEMs). Herein, a new bisphenol monomer bearing ten electron-rich phenyl groups was designed and polymerized with various amounts of electron-deficient 4,4′-dihydroxydiphenylsulfone and 4,4′-difluorobenzophenone to yield dense and selective reaction sites for chloromethylation and quaternization. As the most challenging step, chloromethylation was optimized by tuning the reaction temperature, reaction time, and reactant ratios. Ion exchange capacity, water uptake, anion conductivity, mechanical stability, and alkaline stability of the resulting AEMs were characterized in detail. It is found that chloromethylation reaction needed to be carried out at low equivalent of chloromethylation agents to avoid undesirable crosslinking. The QA-PAEKS-20 sample with an IEC of 1.19 mmol·g⁻¹ exhibited a Cl^– conductivity of 11.2 mS·cm⁻¹ and a water uptake of 30.2% at 80 °C, which are promising for AEM applications.

中文翻译：

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带有聚电子富集苯基的阴离子交换膜聚芳醚酮砜的氯甲基化和季铵化

摘要

离子分离对于实现阴离子交换膜（AEM）的高离子电导率至关重要。本文中，设计了一种带有十个富电子基团的新型双酚单体，并将其与各种数量的缺电子的4,4'-二羟基二苯砜和4,4'-二氟二苯甲酮聚合，以生成致密且选择性的氯甲基化和季铵化反应位点。作为最具挑战性的步骤，通过调整反应温度，反应时间和反应物比例来优化氯甲基化。详细描述了所得AEM的离子交换容量，吸水率，阴离子电导率，机械稳定性和碱稳定性。发现氯甲基化反应需要在低当量的氯甲基化剂下进行以避免不希望的交联。^-1表现出氯^- 11.2毫秒电导率·厘米^-1，在80℃，这是有希望的应用AEM 30.2％的吸水率。