| 摘要 |
PURPOSE:To obtain the titled dry semipermeable membrane having substantially the same fractional mol.wt. and permeability as the starting wet semipermeable membrane by treating the wet semipermeable membrane with a water-miscible organic solvent, then treating with a nonpolar organic solvent, and drying the membrane. CONSTITUTION:A wet semipermeable membrane (having about 100-2X10<5> frational mol.wt.) consisting of a polyamide having a repeating unit shown by formula I, a polyimide having a repeating unit shown by formula II, and a poly sulfone having a repeating unit expressed by formula III or IV is kneaded with water, and then treated with a water-miscible organic solvent which does not swell or dissolve the polymer constituting the semipermeable membrane to replace the water contained in the membrane with the water-miscible organic solvent. Then the membrane is treated with a nonpolar solvent which can be mixed with the water-miscible organic solvent and is a nonsolvent for the polymer, and having 6-10 solubility parameter to replace the water-miscible organic solvent with the nonpolar solvent, and then dried. |
