homogeenisesti cannot be confused with the polymeeriseoksesta consisting of semi permeable membrane and method for its manufacture

摘要

A semipermeable membrane is described whichcomprises a homogeneously miscible polymer blend ofan aromatic polyamide and polyvinylpyrrolidone. Thearomatic polyamide is in particular formed ofrecurrent units of the formula I:(see formula I)wherein E1 and E2 are identical or different and areselected from the groupings(see formula II)-Ar1-, and-Ar1-X-Ar2,where Ar1 and Ar2 are the same or different1,2-phenylene, 1,3-phenylene or 1,4-phenylene groupswhich may be substituted by (C1-C6) -alkyl , (C1-C6)-alkoxy,-CF3 or halogen and X denotesa) a direct bond or one of the followingdivalent groups-O-, -C (CF3)2-, -SO2-, -CO-, -C(R1)2-, with R2being hydrogen, (C1-C6)-alkyl or fluoroalkylhaving from 1 to 4 carbon atoms in the alkylgroup orb) -Z-Ar1-Z-, where Z is one of the groups-O- and -C(CH3)2 orc) -O-Ar1-Y-Ar2-O-, where Y has the meaning givenunder Xa) above.The membrane has pronounced hydrophilic propertiesand is moreover stable to hydrolyzing agents andoxidants and to the action of heat. It is alsoresistant to organic solvents and microorganisms andexhibits low adsorption of proteins.A process for producing the membrane and aprocess for modifying the retention capacity thereofare also described. The membrane is produced byspreading a solution of the homogeneously misciblepolymer blend on a planar substrate andprecipitating the blend. Retention capacity ismodified by heat treatment.