| 摘要 |
<p>Rigid aromatic, polyimide or copolyimide, highly selective asymmetric gas separation membranes are obtained from diphenyldi(trifluoromethyl)methane 3,4,3',4'-tetracarboxylic acid dianhydride and a monoaromatic metadiamine or a mixture of monoaromatic metadiamines. The membranes are manufactured by a method comprising: - dissolving the polymer in a volatile solvent which is specific to the polymer, - applying a film of the polymer solution to a support or extruding a tube of the polymer solution, - partially evaporating the solvent from the film or tube, bringing the film or tube into contact with a liquid coagulant which is specific to the polymor solution, and drying the coagulated film or tube.</p> |
