FTIR和ESR法研究离聚体溶液中的离子相互作用

Studies on the Ionic Interaction in lonomer Solution by FTIR and ESR

磺化乙丙三元共聚物(SEPDM)离聚体在二甲苯/5％正己醇混合溶剂中具有特异的粘浓关系和粘温关系,估计是由于金属离子被己醇溶剂化而影响离子间相互作用引起的,但尚未有更多的实验数据加以验证.本文用FTIR和ESR方法对SEPDM离聚体溶液作进一步考察,发现金属离子与己醇确实存在溶剂化效应,溶剂化程度与离子的大小、浓度和温度有关,它直接影响离子在溶液中存在的状态(单离子或离子聚集体),这些结果为从分子水平了解离聚体溶液性质提供了理论根据.用波谱方法研究离聚体溶液中的离子相互作用尚鲜见报道.

FTIR and ESR have been used to study the influence of the xylene/hexanol ratio on the cation-anion and cation-cation interactions in sulfonated EPDM ionomers.FTIR results show that the interaction between the solvated metallic ions and SO3-is in the order Li<Na<K,while for the ions without solvation the order is the reverse (Li>Na>K).The ESR spectra of SEPDM-Mn ionomers indicate that both isolated Mn2+ and Mn2+ cluster exist in the solution.The Mn2+ cluster is favored in less hexanol cosolvent and at high temperature,which is believed to be the reason for the viscosity increase of the ionomer solution with increasing temperature.