天然纤维粉体对聚偏氟乙烯多孔膜结构与性能的影响

Effects of natural fiber powder on the structure and performance of polyvinylidene difluorid membrane

采用溶液相转化法制备了羽绒粉体/聚偏氟乙烯(PVDF)和苎麻粉体/PVDF复合微孔膜,对膜结构和性能进行了分析和测试。结果显示苎麻粉体/PVDF复合膜、羽绒粉体/PVDF复合膜、纯PVDF膜的形态一致,均为致密皮层和多孔亚层,孔隙率和水通量依次降低,结晶度依次增加;但膜的吸水率按照羽绒粉体/PVDF复合膜、苎麻粉体/PVDF复合膜、纯PVDF膜依次下降;这说明复合膜水通量主要受孔隙率的影响,而膜吸水率主要受纤维粉体吸水性大小的影响。膜力学性能测试显示加入粉体之后,PVDF膜的强度增加,断裂伸长率有所下降。

Down powder/PVDF composite membrane and ramie powder/PVDF composite membrane were prepared by the solution phase inversion method,and membrane structure and performances were measured.The experimental results revealed that the porosity and water fluxes decreased gradually as the following order of ramie powder/PVDF composite membrane,down powder/PVDF composite membrane and PVDF membrane.While the membrane crystallinity increased according to the above order.These three membranes displayed the same membrane morphology with the dense skin layer and the porous sublayer.But the water-absorbability reduced in sequence of down powder/PVDF composite membrane,ramie powder/PVDF composite membrane and PVDF membrane.These results showed that porosity had a significant influence on membrane water fluxes and membrane water-absorbability was controlled by hydrophilicity of fiber powder.For membrane mechanical properties,fiber powder addition made PVDF membrane strength enhance with the elongation reduction.