Aromatic sulfonated polymers are a class of important proton exchange membranes. With the aim of further enhancing their properties at low levels of ion-exchange capacity (IEC), a class of new poly(ether sulfone ketone)s containing multiple sulfonic acids on the side chains of the sulfonated structural units (sPh-PESK-xx) were designed and prepared by a convenient and mild post-sulfonation reaction process. The structures of the related monomer and copolymers were confirmed by IR and NMR analysis. The resulting membranes from solution casting of these aromatic sulfonated polymers showed overall good performance at low IEC levels. Their proton conductivities were in the range of 110–154 mS cm⁻¹, while their swelling ratios were in the range of 6.2%–16.1% at 80 °C. Meanwhile, they also displayed good thermal and chemical oxidative stabilities. The results confirmed that the incorporation of a high density of pendant sulfonic groups is an effective way to improve the performance of aromatic sulfonated polymers.

中文翻译：

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通过方便和温和的后磺化反应，含有高密度侧基磺酸基的质子传导性聚醚砜酮

芳族磺化聚合物是一类重要的质子交换膜。为了在低水平的离子交换容量（IEC）下进一步增强其性能，一类新型的聚醚醚酮在磺化结构单元的侧链上含有多种磺酸（sPh-PESK- xx）是通过方便且温和的后磺化反应过程设计和制备的。通过IR和NMR分析确认了相关单体和共聚物的结构。由这些芳族磺化聚合物的溶液流延得到的膜在低IEC水平下显示出总体良好的性能。它们的质子电导率在110–154 mS cm ^-1的范围内，而它们在80°C时的溶胀率在6.2％–16.1％的范围内。同时，它们还表现出良好的热和化学氧化稳定性。结果证实，高密度侧基磺酸基的引入是改善芳族磺化聚合物性能的有效方法。