离子交换纤维微观形貌特点及结构修饰研究

利用比表面积测试仪、扫描电子显微镜等物理化学方法对颗粒与纤维状离子交换剂的链间交联与微观形貌进行了研究,通过刚性交联剂对聚丙烯-苯乙烯-二乙烯基苯(PP-ST-DVB)离子交换纤维骨架结构进行了修饰改造。结果表明:离子交换纤维由于不能通过交联剂与致孔剂参与下的单体聚合构建具有丰富微孔的高分子骨架,所以不存在丰富孔结构和高比表面积特征,其内部为连续凝胶相结构;外比表面积大、传质距离短、交联键分布均匀是其反应动力学和渗透压稳定性能优异的主要原因;刚性交联剂在PP-ST-DVB纤维上的附加交联反应使其比表面积从原来的0.5 m~2/g提高到200 m~2/g以上,附加交联反应所形成的分子尺度微孔孔径分布窄,具有超高交联树脂的结构特点。

Micromorphology and structure modification of ion exchange fiber

The interchain crosslinking and micromorphology of different ion exchange fiber and resin were investigated by specific surface area test and scanning electron microscope.The bone structure of polypropylene-styrene-divinylbenzene(PP-ST-DVB) ion exchange fiber was modified with rigid crosslinking agent.The results showed that a polymer matrix with abundant micropores can not be built via monomer polymerization in presence of crosslinking and pore-forming agents,so the ion exchange fiber possessed the characteristics of continuous gel-phase and low specific surface area;the superior reaction kinetic behavior and osmotic pressure stability of the fiber were attributed to the high external specific surface area,short mass transfer route and homogeous crosslink density;attributing to the additional crosslinking reaction between the rigid crosslinking agent and PP-ST-DVB fiber, the specific surface area of PP-ST-DVB fiber was increased from 0.5 m~2/g to over 200 m~2/g and the obtained PP-ST-DVB fiber had a narrow micropore diameter distribution which was similar as the characterictics of hypercrosslinked ST-DVB resin.