SEPARATION PERFORMANCES OF THE MEMBRANES PREPARED FROM SCHIFF-BASES OF POLY(ALLYLAMINE) FOR ORGANIC SOLUTES

Permselective separation between water and water-soluble organics was investigated up to high concentration levels through crosslinked and metal complexed membranes of hybrid Schiff-base derivatives of poly(allylamine), which were prepared by the reaction between pyridine-2-carboxaldehyde (P) and salicyl aldehyde (S) with varying ratios of P/S. The complexed membranes had strong hydrophilic character and showed an increased flux and high permselective separation for t-butanol and tetrahydrofuran at high concentrations. Correlations between the performance of the complexed membranes and the physicochemical parameters, especially the solubility parameters, of alcohols and aprotic solutes were studied and discussed. It was found that a membrane with a higher P/S value tended to reject the aprotic solute with a smaller solubility parameter, while other physical properties of the alcohols also effected the alcohol separation.