HIGHLY SELECTIVE ASYMETRICAL MEMBRANES USED FOR THE SEPARATION OF GASES, AND PROCESS FOR THEIR FABRICATION

摘要

we describe the asymmetric membranes for gas separation copolyimides rigid aromatic polyimides and high selectivity to the pyromellitic acid, the monomer (trifluoromu00e9th diphu00e9nyldiyl) methane 3,4,3 ', 4', and a mu00e9tadiamine monoaromatique dianhydride or a mixture of mu00e9tadiamines monoaromatics.these membranes are produced by a process which includes:? the dissolution of polymer in a volatile solvent, the polymer species.???? the application of a film of polymer solution on a substrate, and the extrusion of a tube of a polymer solution. the partial evaporation of the solvent from the film or tube.the introduction of the film or tube with a liquid coagulation of the polymer solution and drying the coagulated film or tube.