| 摘要 |
1345308 Permoselective copolymer membranes MONTECATINI EDISON SpA and CONSIGLIO NAZIONALE DELLE RICERCHE 4 May 1972 [4 May 1971] 21051/72 Heading B5B [Also in Division C3] Permoselective membranes are prepared from copolymers of 10-90 mole per cent of a vinylpyridine, vinylpiperidine or vinylquinoline, optionally having up to 2 alkyl substituents, with vinylidene chloride and/or α-chloroacrylonitrile by the following steps: (a) forming a solution in an organic solvent, e.g. dimethylformamide, of the copolymer, preferably mixed with another polymer containing double bonds and/or halogen atoms, such as poly(vinyl chloride), (b) casting the solution, e.g. on a glass plate, and evaporating the solvent at 80‹ C. or below to produce the membrane, (c) heating above 80‹ C. to cross-link the polymer(s), and (d) quaternizing some or all of the nitrogen atoms in the copolymer. Step (d) is carried out by treating the membrane with a quaternizing agent dissolved in a solvent capable of penetrating the membrane. This reaction is preferably carried out in two stages, the second at a higher temperature than the first, and may also involve treatment first with a polyfunetional quaternizing agent and then with a monofunctional one. In examples membranes derived from 2- or 4-vinylpyridine and vinylidene chloride or chloroacrylonitrile are quaternized with diiodoethane and/or methyl iodide. |
