COMPOSITE POLYMERIC MEMBRANES FOR THE SEPARATION OF MIXTURES OF GASES AND THE METHOD FOR PREPARATION THE SAME

摘要

Certain composite polymeric membranes for the separation of mixtures of gases have improved (higher) selectivity in the separation of mixtures He/N2 and O2/N2, suitable mechanical properties and a high permeability. They consist of a polymeric porous base from poly-2,6-dimethyl-1,4-phenyleneoxide and a polymeric selective layer formed from polyamidoimide of the general formula I, (I) or from an interpolymeric equimolar complex of PAI-1 with polyvinylpyrrolidone, or from an aromatic polyimide of general formula II, (II) or of the general formula III, (III) or from polymeric imides of the general formula IV, (IV) or also from their copolymers with styrene, methyl methacrylate, methyl acrylate, and dimethylaminoethyl methacrylate. A method for the preparation of these membranes involves saturation of the porous base of poly2,6-dimethyl-1,4-phenyleneoxide with an organic solvent inert to it, drying, and coating with a 1-25 wt.-% solution of the selective polymer in an organic solvent which is incompatible with the said organic liquid.