SUPPORTED POROUS ACETATE-CELLULOSE MEMBRANE AND METHOD OF PREPARATION THEREOF Russian patent published in 2002 - IPC

FIELD: membrane technology. SUBSTANCE: invention provides porous acetatecellulose membrane supported by lavsan paper, which is impregnated with acetate-cellulose polymer with average pore size 0.01 to 0.45 mcm and consisted of mixture of cellulose acetates having different amounts of bound acetic acid: 54.6-55.2 wt % and 53.0-57.5 wt %, and up to 7.0 wt % low-molecular fractions, support and polymer being also impregnated with glycerol in amounts from 50.0 to 80.0 wt parts per 100 wt parts polymer. Membrane is prepared according to "dry technique": acetate mixture is dissolved in organic solvent and solution is structured by system of, vol parts: methylene dichloride 1, isopropyl alcohol 3.3-7.5, glycerol 0.6-7.5, and desalted water 0.35-1.0. Simultaneously, membrane is formed at subjected to heat treatment under conditions of free evaporation, which is accomplished in three steps at progressively increased temperature and constant absolute humidity: up to 5.0 g/cu.m. EFFECT: improved strength, technological, and operation characteristics. 5 cl, 1 dwg, 2 tbl, 6 ex