| abstract |
Water permeable reverse osmosis membranes are prepared by interfacially polymerizing on a microporous support an essentially monomeric polyamine reactant having at least two amine functional groups per reactant molecule, and an essentially monomeric, at least trifunctional cyclic chloroformate amine-reactive reactant, wherein at least one of the functional groups is a chloroformyl group and the remaining functional groups of the amine-reactive reactant, if any, are acyl halides. The polymerization is preferably carried out in the presence of a monomeric amine salt, which increases the flux rate of the resulting membrane. In addition, an aromatic polyfunctional acyl halide and/or a polyfunctional cycloaliphatic acyl halide may be used in conjunction with the cyclic chloroformate in order to increase flux rates and possibly other desired properties. A preferred cyclic chloroformate is 5-chloroformyl isophthaloylchloride. |