聚乙烯阴离子交换膜掺混聚偏氟乙烯改性表征

Characterization of polyethylene anion exchange membrane blending PVDF modification

聚偏氟乙烯(PVDF)因含氟乙烯基单体,拥有良好的化学稳定性、热学稳定性和机械性能,与其他高分子膜材料相比更容易提高离子交换膜的性能。本实验采用热压法制备PVDF聚乙烯阴离子交换膜,探讨了PVDF含量对膜性能的影响,如膜电阻、离子交换容量、耐破度、含水率和选择透过性。利用红外光谱仪及扫描电子显微镜表征手段对PVDF膜表面性质和结构进行了分析。结果表明,当PVDF含量增加时,膜面电阻、耐破度升高。离子交换容量、含水率,反离子选择透过性降低。虽然PVDF的添加导致含水率、交换容量等膜性能的下降,但耐破度的升高表明膜稳定性和机械性能得到了提升,这赋予PVDF聚乙烯膜一定的使用价值。

polyvinylidene fluoride(PVDF)has good chemical stability,thermal stability and mechanical properties because of its fluorine-containing vinyl monomer.Compared with other polymer membrane materials,it is easier to improve the performance of ion exchange membrane.The effect of PVDF content on membrane properties,such as membrane resistance,ion exchange capacity,breaking resistance,moisture content and selective transmittance,was studied.Infrared spectrometer and scanning electron microscope were used to analyze the surface properties and structure of PVDF film.As the content of PVDF increases,the membrane surface resistance increases,the ion exchange capacity and moisture content decrease,the breaking resistance increases,and the selective transmissivity decreases.While the addition of PVDF leads to the decrease of some membrane properties,the increase of breaking resistance indicates that the stability and mechanical properties of the membrane have been improved,and a certain amount of PVDF can improve the selective transmittance,which gives PVDF polyethylene film certain use value.