SEPARATION OF AQUEOUS SOLUTION OF ORGANIC MATTER BY PERMEATION AND VAPORIZATION

摘要

PURPOSE:To accelerate the selective permeation and vaporization of water from an aq. soln. of org. matter by bringing the aq. soln. into contact with an asymmetric separating membrane formed with soluble arom. polyimide having a specified compsn. as a heat resistant polymer. CONSTITUTION:A flat membrane or a hollow fiber membrane as an asymmetric separating membrane is formed with soluble arom. polyimide as a heat resistant polymer. The polyimide contains 60-100mol repeating units represented by formula I and the remaining repeating units are units each produced from biphenyltetracarboxylic acids and an arom. diamine compd. having 2-5 benzene rings as an arom. diamine component. The separating membrane can be used to separate and concentrate an aq. soln. of org. matter nearly independently of the kind and concn. of the org. matter and has satisfactory heat, water and solvent resistances and durability.