Proton exchange membranes (PEMs) play a critical role in many electrochemical devices that could solve the shortcomings of current energy storage and conversion systems. Hydrocarbon-based PEMs are an attractive alternative for replacing the state-of-the-art perfluorosulfonic acid PEMs; however, synthetic routes are generally limited to sulfonation of aromatic units (pre- or postpolymerization functionalization). Here we disclose a facile and scalable one-pot synthetic method of converting an alkyl halide functionality to a sulfonate in polymer systems. With this method, sulfonated hydrocarbon PEMs can be conveniently prepared from a precursor polymer of anion exchange membranes which have recently experienced significant advances. Polyphenylene type PEMs (BPSA and mTPSA in this report) were generated in one-pot S_N2 reaction of bromoalkyl side chains of polymers followed by oxidation. These PEMs showed excellent proton conductivity with BPSA showing 250 mS/cm in water at 80 °C, nearly 1.5 times higher than that of Nafion 212. Furthermore, the separation of the sulfonic acid group from the rigid backbone with a flexible alkyl chain mitigates excessive water uptake and in-plane swelling ratio of the polymer, despite having a high ion exchange capacity of 2.6 mequiv/g. Oxidative stability was also shown to be superior for hydrocarbon-based PEMs with negligible changes in mass, NMR, and proton conductivity.

中文翻译：

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阴离子交换膜前驱体一锅法合成质子交换膜

质子交换膜（PEM）在许多电化学装置中起着至关重要的作用，可以解决当前能量存储和转换系统的缺点。基于烃的PEM是替代最新的全氟磺酸PEM的有吸引力的替代方法。然而，合成途径通常限于芳族单元的磺化（预聚合或后聚合官能化）。在这里，我们公开了一种在聚合物体系中将卤代烷官能团转化为磺酸盐的简便且可扩展的一锅合成方法。用这种方法，可以从阴离子交换膜的前体聚合物方便地制备磺化的烃PEM，该阴离子交换膜的前体聚合物最近已经取得了重大进展。聚苯型PEM（BPSA和m该报告中的TPSA是在聚合物的溴烷基侧链的一锅S _N 2反应中生成的，然后进行氧化。这些PEM表现出优异的质子传导性，在80°C的水中BPSA表现出250 mS / cm，几乎是Nafion 212的1.5倍。此外，磺酸基与带有柔性烷基链的刚性骨架之间的分离减轻了过度尽管具有2.6mequiv / g的高离子交换容量，但是聚合物的水吸收率和面内溶胀率。对于基于烃的PEMs，其质量，NMR和质子传导率的变化可忽略不计，其氧化稳定性也被证明是优越的。