聚酰亚胺膜溶剂体系的筛选及其作用

Selection and role of solvent system for polyamide membrane

采用一种新型的可溶性聚酰亚胺ODPA-BAPP为膜材料,分别用溶度参数法和黏度法对溶剂进行了筛选,然后选定N-甲基吡咯烷酮(NMP)作为溶剂,分别采用挥发性强的四氢呋喃、丙酮、乙醚作为第二溶剂(共溶剂),讨论了它们对成膜过程中的凝胶速率及形成的膜表面形貌的影响.实验结果表明:(1)NMP对ODPA-BAPP的溶解性最好;(2)第二溶剂的挥发性能越好,浇铸膜时的凝胶速率就越慢,就越利于形成表面致密结构的膜.

The polyamide membranes were prepared by using a novel ODPB-BAPP condensation polymer as the membrane material. N-methyl pyrrolidone was selected as the major solvent depending on the data of both,sol, ubility parameter and casting solution viscosity. The volatile solvents, such as tetrahydrofuan, acetone and ether, were added respectively in the coating solution as the co-solvents. The results showed that N - methyl pyrrolidone has the best solvation on polyimide, and the volatile solvent can decrease gelation rate owing to the formation of dense membrane surface.