SEPARATION OF AQUEOUS SOLUTION OF ORGANIC MATTER BY PERMEATION AND VAPORIZATION

摘要

PURPOSE:To allow water to permeate and vaporize selectively from an aq. soln. of org. matter and to highly maintain the permeation and vaporization 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:Soluble arom. polyimide is dissolved in a phenol type solvent. 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 resulting soln. is spread and brought into contact with a solidifying bath to form a flat membrane or a hollow fiber membrane as an asymmetric separating membrane. An aq. soln. of org. matter is brought into contact with the separating membrane to allow water to permeate and vaporize selectively from the aq. soln.