| 초록 |
A solvent resistant porous polyimide asymmetric membrane have been successfully fabricated via thermal imidization of poly(amic acid) which is precursor of polyimide prepared by immersion precipitation method. We investigate on the liquid-liquid demixing process using different types of nonvolatile solvents such as dimethylacetamide (DMAc) and γ-butyrolactone(GBL). The effect of coagulation media for the change of the membrane morphology is discussed. The membrane structure was variable by changing the ratio of nonvolatile solvents, i.e., DMAc and GBL. In the case of using the ethanol as coagulating media, we could find obtain uniform pore size distribution in the membrane structure. On the other hand, in the case of using water as coagulating media, macroporous membrane structure was obtained. These results might be related to different solubility parameters of DMAc/GBL for water or ethanol. |
