Permselective membranes of diacyl hydrazide-containing aromatic polymers having selected metals complexed therewith

Claim 1

A permselective polymeric asymmetric membrane comprising i. a diacyl hydrazide-containing, substantially linear, aromatic, synthetic organic polymer comprising alternating linking groups and organic radicals, and ii. one or a mixture of Co(II), Ni(II), Cu(II) and Pd(II) metal wherein the metal is in square planar coordination complex relationship with the polymer of (i), the permselective membrane characterized by having metal complexed with the polymer in the amount of at least one-gramatomic weight of metal for each 20 gram-formula-weights of linking groups, the polymer of (i) being further characterized by having the formula (-L-R-).sub.n wherein the --L-- groups and --R-- radicals are alternating, each --L-- group is a linking group and at least about 50 percent of the --L-- groups contain a nitrogen atom in the polymer chain, and at least 5 percent of the --L-- groups contain the diacyl hydrazide group ##EQU7## each --R-- group is an organic radical and at least about 50 percent of the --R-- groups consist essentially of a 5-member ring or a 6-member ring subject to resonance bonding; and the degree of polymerization is defined by n, an integer sufficiently large to provide film-forming molecular weight; the polymer having a solubility at 25°C. of at least about 10 percent by weight in a solvent medium consisting essentially of from 0 to 3 percent by weight of lithium chloride dissolved in at least on member selected from the group consisting of dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and hexamethylphosphoramide.