Carboxyl-terminated benzimidazole-assisted cross-linked sulfonated poly(ether ether ketone)s for highly conductive PEM with low water uptake and methanol permeability
作者:Miaomiao Han、Gang Zhang、Ke Shao、Hongtao Li、Yang Zhang、Mingyu Li、Shuang Wang、Hui Na
DOI:10.1039/b926354c
日期:——
A carboxyl-terminated benzimidazole trimer was synthesized as a crosslinker by controlling the ratio of 3,3′-diaminobenzidine and isophthalic acid. Composite membranes were obtained by mixing the benzimidazole trimer and sulfonated poly(ether ether ketone) (SPEEK) together. Cross-linked membranes were obtained by heating the composite membranes at 160 °C. All of the properties of the cross-linked membranes were significantly increased, including proton conductivity, methanol permeability and water uptake due to the more compact structure compared to the non-cross-linked membranes. The cross-linked SPEEK-BI7 and cross-linked SPEEK-BI11 had excellent proton conductivities (0.22 and 0.19 S cm−1) at 80 °C, which were higher than that of Nafion 117 (0.125 S cm−1). Transmission electron microscopy (TEM) analysis revealed a clear microphase separated structure of cross-linked membranes. Other properties, such as thermal and mechanical stability, required for use as a proton exchange membrane (PEM) have been investigated. The cross-linked membranes showed improved properties over membranes without crosslinking.
通过控制3,3′-二氨基联苯胺和间苯二甲酸的比例,合成了羧基端苯并咪唑三聚体作为交联剂。通过将苯并咪唑三聚体和磺化聚醚醚酮(SPEEK)混合,获得了复合膜。通过在160℃下加热复合膜,获得了交联膜。与非交联膜相比,交联膜的结构更加紧凑,因此其所有性能都得到了显著提升,包括质子电导率、甲醇渗透性和吸水率。在80℃下,交联的SPEEK-BI7和交联的SPEEK-BI11具有优异的质子电导率(分别为0.22和0.19 S cm-1),高于Nafion 117(0.125 S cm-1)。透射电子显微镜(TEM)分析揭示了交联膜清晰的微相分离结构。研究人员还研究了作为质子交换膜(PEM)所需的其他性能,如热稳定性和机械稳定性。与未交联的膜相比,交联膜的性能得到了改善。