低临界共溶温度PSf-DMAc-PEG体系微孔膜及其性能表征

摘要

Polysulfone (PSf)-N,N-dimethyl acetamide(DMAc)-polyethylene glycol (PEG200,PEG400 and PEG600) systems with low critical solution temperatures (LCST) were discussed.PSf-DMAc-PEG systems with LCST were confirmed by theory and experiments.PSf microporous membranes were fabricated by thermally induced phase separation with lower critical solution temperature (LCST-TIPS or reverse thermally induced phase separation,RTIPS).The effects of coagulation bath temperatures,membrane preparing methods and compositions of casting solutions on morphologies and performances of PSf microporous membranes were discussed.Comprehensive mechanical properties of the membrane prepared by the mechanism of RTIPS were better than that by nonsolvent induced phase separation (NIPS).When the mass ratio of PEG400/DMAc was 1.1 and coagulation bath temperature was 60 ℃,the membrane permeability and mechanical property were better as follows:the membrane flux was 670 L/(m2 · h · bar),the average pore size was 0.060μm and the break strength was 5.62 MPa.%讨论了聚砜(PSf)-N,N-二甲基乙酰胺(DMAc)-聚乙二醇(PEG200、PEG400和PEG600)低临界共溶温度(LCST)体系；通过理论和实验验证了其LCST体系的存在,利用LCST的热致相分离(LCST-TIPS或Reverse thermally induced phase separation,简称RTIPS)法制备了PSf微孔膜,讨论了凝胶浴温度、制膜方法、铸膜液组成对PSf微孔膜的结构及性能影响.通过RTIPS机理所成膜综合力学性能优于非溶剂致相分离(NIPS)法所制备的膜,当PEG400:DMAc质量比为1.1∶1,成膜水浴温度60℃时,膜渗透性能和机械性能较好,其膜通量670 L/(m2·h·bar)(1 bar=0.1 MPa),平均孔径0.060 μm,断裂强度5.62MPa.