| 摘要 |
1380484 Fractionation AGENCE NATIONALE DE VALORISATION DE LA RECHERCHE 7 Sept 1972 [9 Sept 1971 10 Sept 1971] 41608/72 Headings BIB and B1X A process for the fractionation of a mixture of at least two components comprises contacting the mixture with one surface of an organic membrane carrying, radicals introduced by graft copolymerization, while a chemical potential gradient is maintained between the two surfaces of the said membrane by maintaining the other surface thereof under reduced pressure or by sweeping it with a gaseous stream, and one one side of the -membrane an enriched fraction of one component is recovered and on the other side an enriched fraction of the other component is recovered, wherein a membrane is used which is formed of a thin sheet of fluorinated polymer, into the mass of which have been introduced, by graft polymerisation, radicals derived from a polar monomer having an ability to interact with one of the components and substantially an absence of such an ability with respect to the other component, the first named component being thus preferentially diffused through the membrane. The process may be used (a) to separate a chloroform/ hydrocarbon mixture using a membrane composed of P.T.F.E. carrying radicals derived from poly 4-vinylpyridine or polyvinylpyrrolidone, (b) to dehydrate alcohols by selective diffusion through a membrane obtained by introducing by graft copolymerization, radicals derived from 4-vinyl-pyridine or vinylpyrrolidone into a sheet of P.T.F.E., (e) for the pervaporation of a water/N,N dimethylacetamide using a membrane composed of P.T.F.E. carrying radicals derived from vinyl-4-pyridine, (d) for the dehydration of nitric acid by diffusion of water through a membrane composed of polytetrafluoroethylene and sulphonated polystyrene, (e) for separating a mixture of water and nitric acid by selective diffusion of nitric acid through a membrane composed of polytetrafluoroethylene and polyvinylpyrrolidone, (f) to separate a methanol/methyl acetate mixture by diffusion of methanol through a membrane composed of P.T.F.E. carrying radicals derived from 4-vinylpyridine or N-vinyl-pyrrolidone and (g) to dehydrate N,N-dimethyl formamide .by selective diffusion of water through a membrane of P.T.F.E. into which have been introduced, by graft polymerisation, radical(s) derived from N-vinylpyrrolidone. |
