POLYSULFONE SURFACED MEMBRANE JP 28FEB8560-40

摘要

Hydroquinone and dichlorophenysulfone are reacted to make a polysulfone having recurring units of formula (A): -0-(C6H4)n-0-C6H4-para-SO2-C6H4- where n is an integer: this optionally is copolymerized with up to 10 mole% of units (B): (-0-C6H4-SO2-C6H4)2, straight chain; the (co)polymer is dissolved in 97-98% sulphuric acid so as to substantially sulfonate the rings of units (A) but not of (B); the product has a molecular weight (shown by its viscosity in solution) sufficient to form a thin uniform film. …The (co) polymer is dissolved in concn. of 0.05-10wt% in an alkylene glycol alkyl ether optionally admixed with up to 5 wt% of a non-protonic polar organic solvent (e.g. dimethyl sulfoxide) together with 0.01-80 wt% of a water-soluble and low volatile additive (e.g. a polyhydric alcohol or an inorganic salt), the solution is coated on a dry ultrafiltration menbrane as a support (e.g. a polymer, preferably a polysulfone) and the solvent is evaporated. Any remaining additive is washed out. Choice of additive affects the membrane performance. …The product is a composite semipermeable membrane composed of the sulfonated (co) polysulfone of thickness 0.01-5um on the support and has a pure water flux higher than 3m<3>/m<2> day and good resistance to chlorine, acid and alkali; it is used for reverse osmosis and ultrafiltration.