Wang Yu, Wang Yudong, Sahu Sushant, Gallo August A, Zhou Xiao-Dong
Department of Chemistry, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
Institute for Materials Research and Innovation, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
Polymers (Basel). 2023 Jan 9;15(2):352. doi: 10.3390/polym15020352.
Tetrakis(dialkylamino)phosphonium (TKDAAP) compounds exhibit extraordinary base resistance, a prerequisite feature for high-performance anion exchange membranes (AEMs). It is, however, challenging to synthesize a TKDAAP compound with reactive functionality that can be used to link the cation to a polymer backbone. In this study, two TKDAAP compounds with alkyne functionality were synthesized and incorporated into an azide-modified SBS triblock copolymer backbone via Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) "click" chemistry. The properties of the resulting AEMs were characterized. It was found that (1) the triazole linker between the cation and the polymer backbone was stable under alkaline conditions; (2) varying the substituents of TKDAAP compounds could dramatically alter the stability; and (3) increasing the hydrophilicity of the AEM was an efficient way to enhance its ionic conductivity. Using clickable TKDAAP compounds makes it easy to combine various cations into polymer backbones with adjustable cation content, thus potentially leading to an efficient way to screen a wide variety of polyelectrolyte structures to identify the most promising candidates for high-performance AEMs.
四（二烷基氨基）鏻（TKDAAP）化合物表现出非凡的耐碱性，这是高性能阴离子交换膜（AEM）的一个必备特性。然而，合成具有可用于将阳离子连接到聚合物主链的反应性功能的TKDAAP化合物具有挑战性。在本研究中，合成了两种具有炔烃功能的TKDAAP化合物，并通过铜（I）催化的炔烃-叠氮化物环加成（CuAAC）“点击”化学将其引入到叠氮化物改性的SBS三嵌段共聚物主链中。对所得AEM的性能进行了表征。结果发现：（1）阳离子与聚合物主链之间的三唑连接基在碱性条件下稳定；（2）改变TKDAAP化合物的取代基可显著改变稳定性；（3）提高AEM的亲水性是提高其离子电导率的有效方法。使用可点击的TKDAAP化合物能够轻松地将各种阳离子组合到阳离子含量可调的聚合物主链中，从而有可能成为一种筛选各种聚电解质结构以确定高性能AEM最有前景候选物的有效方法。
