Formation of 6FDA-p-TeMPD Polyimide Asymmetric Membranes by Phase Separation Process

초록

The effects of solvents(DMAc, NMP, 1,4-dioxane) and nonsolvents(H2O, MeOH, n-hexane) on the morphology of 6FDA-p-TeMPD polyimide membrane, prepared by the wet phase inversion method, were studied. In the polymer/solvent/nonsolvent ternary system, the binodal curve, the coagulation value and the relative light transmission were measured, and the solubility parameter difference was calculated. The onset state and the rate of liquid-liquid demixing were predicted and the morphology of membrane was analized. The proper solvent-nonsolvent pairs were selected for the formation of asymmetric membrane having a thin, dense skin layer and porous support sublayer. It was found that the solubility parameter difference and binodal curves are good criterion for the selection of the solvent-nonsolvent pair.