| 摘要 |
The chemical composition of the protective layer is different from the chemical composition of the separated layer. The specific permeate flow of the protective layer is at least 2 times higher than the specific permeate flow of the separated layer. The selectivity of the protective layer is 2 times smaller than selectivity of the separated layer. The protective layer is composed of polyurethane, a derivative of polysaccharides, polyacrylacid ester, polyvinyl alcohol, a copolymer of vinyl alcohols with vinylchoride, ethylene, vinylacetate and/or an acryl acid derivative, polyvinylacetate and/or mixture of the compounds. Membrane for separating mixtures by pertraction, pervaporation, permeation condensable gases or vapor-permeation has an active separating layer which is formed as composite-membrane or integral-asymmetrical membrane. The membrane yields a homogeneous protective layer on the thin side with a high number error-site separated layer. The protective layer has a diameter of 0.01 to 1micronm and comprises a soluble polymer, copolymer or polymer mixture. An Independent claim is include for the process of manufacturing the membrane. |
