Cross-linked hydroxide conductive membranes with side chains for direct methanol fuel cell applications
作者:Shuai Xu、Gang Zhang、Yang Zhang、Chengji Zhao、Liyuan Zhang、Mingyu Li、Jing Wang、Na Zhang、Hui Na
DOI:10.1039/c2jm16593g
日期:——
A series of novel poly(ether ether ketone) copolymers containing methyl groups on the side chain were prepared based on a new monomer (3,4-dimethyl)phenylhydroquinone. Then a series of hydroxide exchange membranes with different IEC values were obtained through bromination and quaternary amination of the copolymers. By adjusting the contents of methyl groups in the copolymers, we could control the final structures of the membranes. The chemical structures of the monomers and copolymers were analyzed by 1H NMR spectroscopy. After that, for the purpose of enhancing the dimensional stability and methanol resistance of the membrane, we prepared cross-linked membranes through a Friedel–Crafts reaction between bromomethyl groups and aromatic rings. The properties of the membranes related to fuel cell application were evaluated in detail. All the membranes showed good thermal and mechanical stabilities and conductivities. Moreover, the cross-linked membranes exhibit better dimensional stabilities and selectivities. Among those membranes, xPEEK–Q-100 showed a high conductivity (0.036 S cm−1 at 80 °C), a low swelling ratio of 6.6% and a methanol permeation coefficient of 2.9 × 10−7 cm2 s−1. The outstanding properties indicated that the application of PEEK–Q-xx membranes in fuel cells was promising.
基于一种新型单体(3,4-二甲基)苯基对苯二酚,制备了一系列侧链上含有甲基的新型聚(醚醚酮)共聚物。然后通过共聚物的溴化和季胺化,得到了一系列具有不同离子交换容量值的氢氧化物交换膜。通过调整共聚物中甲基的含量,我们可以控制膜的最终结构。通过1H NMR光谱分析了单体和共聚物的化学结构。之后,为了提高膜的尺寸稳定性和耐甲醇性,我们通过溴甲基和芳环之间的Friedel-Crafts反应制备了交联膜。详细评估了与燃料电池应用相关的膜性能。所有膜均表现出良好的热稳定性和机械稳定性以及导电性。此外,交联膜表现出更好的尺寸稳定性和选择性。在这些膜中,xPEEK-Q-100表现出高导电性(80℃时为0.036 S cm-1)、低膨胀率(6.6%)和甲醇渗透系数(2.9×10-7 cm2 s-1)。这些优异的性能表明PEEK-Q-xx膜在燃料电池中的应用前景广阔。