PEI交联的PECH/nylon复合阴离子交换膜的制备及性能研究

Preparation and properties of PEI crosslinked PECH/nylon composite anion exchange membrane

聚环氧氯丙烷(PECH)是一种线性高分子聚合物,具有较好的稳定性和成膜性能,且以PECH为基体制备阴离子交换膜,可避免致癌物质如氯甲醚、双氯甲醚的使用,但存在机械强度差与吸水性较大等缺点。本研究采用聚乙烯亚胺(PEI)作为交联剂,通过其与PECH发生交联反应,在其内部形成网状结构限制PECH膜在水中的过度溶胀,从而增强膜的机械强度,同时引入尼龙网布(nylon)作为支撑材料进一步提高膜的力学性能,制备了QCPECH/nylon复合阴离子交换膜。研究结果表明,制备的P1膜在电渗析应用过程中的脱盐效率(94.8%)比商业膜(Neosepta AMX)的脱盐效率(92.4%)更高,由此可见,用PEI交联的PECH/nylon复合阴离子交换膜在电渗析脱盐中具有潜在的发展前景。

Polyepichlorohydrin（PECH） is a linear polymer, with good stability and membrane-forming properties, and the use of polyepichlorohydrin（PECH） polymer as a matrix to prepare anion exchange membrane, which can avoid the use of carcinogenic substances chloromethyl ether, and dicyclopentyl ether. However, the prepared membrane with PECH as matrix has the disadvantages of poor mechanical strength and high water absorption, which limits its wide application in electrodialysis technology. Crosslinking reaction with PECH was carried out by using polyethyleneimine（PEI） as crosslinking agent, and a network structure is formed therein to limit the excessive swelling of the polymer membrane in water, thus to enhance the mechanical strength of the membrane, and introduction of nylon mesh to further improve the mechanical properties of the membrane. In the present work, the QCPECH/nylon composite anion exchange membrane was prepared. The effects of water uptake, swelling degree, ion exchange capacity, mechanical strength, membrane resistance and desalination on the composite anion exchange membrane were investigated. The results showed that the desalination efficiency（94.8%） of the prepared P1 membrane is higher than that of the commercial membrane（92.4%）. It can be seen that the composite anion exchange membrane made of PECH/nylon crosslinked with PEI has the potential for development in electrodialysis desalination.