METHOD OF MANUFACTURING PREVAPORATION COMPOSITE POLYMER MEMBRANE Russian patent published in 1997 - IPC

FIELD: membrane separation. SUBSTANCE: invention is applicable in food and chemical industries, biotechnology, and medicine for dehydration of water-organic mixtures using prevaporation and gas- separation techniques. For wet formation of microporous substrate, 8- 11% polyamodoimide solution with viscosity = 1.2-2.2 dl/g based on 4-chloroformyl-N-(p-chloroformylphenyl)phthalimide and 4,4'- diaminodiphenyl ether in aprotic polar solvent is used, whereas surface diffusion layer is formed from 1-5% chloroform or methylenchloride solution of polyetheramides with = 0.1-1.1 dl/g based on bis(3,4-dicarboxyphenoxy)benzene dianhydride and aromatic diamines selected from series: 4,4'-bis(4"-aminiphenoxy)diphenyl sulfone, 4,4'-bis-(4"-aminophenylthio)diphenyl oxide, and 2,2-bis[4- aminophenoxy)phenyl]propane. EFFECT: enhanced efficiency of process. 2 tbl