Abstract: A synthetic membrane consisting of a mixture of polysulfone and sulfonated polysulfone and not more than 20 wt. % of other polymers, characterized in that the mixture contains 0.5 to 8 wt. % sulfonated polysulfone, possibly as the salt of sulfonic acid, and a method for manufacturing this synthetic membrane, characterized in that one or more solvents are added to a mixture composed of 0.5 to 8 wt. % sulfonated polysulfone, possibly as the salt of sulfonic acid, polysulfone and not more than 20 wt. % of other polymers, the mixture is dissolved to form a polymer solution, the latter is shaped, and precipitated to form a membrane in a precipitating bath by means of one or more precipitating agents.

Abstract: An asymmetric semipermeable membrane for dialysis and/or ultrafiltration is composed of a copolymer of acrylonitrile and acrylic ester and an ionic or ionizable monomer in the form of a hollow fiber. The copolymer is composed of 90.50 to 95.00 wt. % acrylonitrile, 4.99 to 8.60 wt. % acrylic ester, and 0.01 to 0.90 wt. % of the ionic or ionizable monomer. Also provided is a process for its manufacture.

Abstract: A synthetic hydrophilic membrane, and method for manufacturing thereof, in the form of hollow fibers or flat membranes for dialysis and/or ultrafiltration, containing a mixture of polysulfone and sulfonated polysulfone, the mixture containing 65 to 95 wt.% sulfonated polysulfone, possibly as a salt of sulfonic acid, and 35 to 5 wt.% unsulfonated polysulfone. Preferably, up to 12 wt.% water-soluble polymers, based on the total mixture, are added to the mixture of polysulfone and sulfonated polysulfone before formation of the membrane.