A straight forward approach to increase proton conductivity at relatively dry conditions is to increase the number of sulfonic acid groups in the polymer. Although various PFSAs of significantly lower EW can be prepared, the limitation of this approach is that the polymer and membrane properties are also affected, with membranes showing increased water uptake and dimensional swelling. Our approach has been to develop a series of approaches for the cross-linking of PFSAs in order to improve membrane mechanical properties and reduce membrane swelling in the presence of water. Novel side-chain component multifunctional monomers have been developed that are cross-linkable after membrane fabrication. The result of this approach is that a suite of polymers have been synthesized that, after membrane casting and cross linking show excellent proton conductivity, even under conditions of elevated temperature and <50% RH.

中文翻译：

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共价交联复合全氟磺酸膜的研制

在相对干燥的条件下增加质子传导率的直接方法是增加聚合物中磺酸基团的数量。尽管可以制备 EW 显着降低的各种 PFSA，但这种方法的局限性在于聚合物和膜的性能也会受到影响，膜的吸水率和尺寸膨胀会增加。我们的方法是开发一系列用于 PFSA 交联的方法，以改善膜的机械性能并减少膜在水存在下的膨胀。已经开发出在膜制造后可交联的新型侧链组分多功能单体。这种方法的结果是合成了一套聚合物，