SYNTHESIS OF PYRIDINE-MOIETIES-CONTAINING POLY(ACYLHYDRAZONE)S AND SOLUTE SEPARATION THROUGH THEIR MEMBRANES

Poly(acylhydrazone)s containing pyridine moieties were synthesized fro m 2,6-pyridinedicaboxaldehyde and each of five dihydrazides. Although most of the polycondensates were insoluble or sparingly soluble and of low molecular weight, the polymers from malonyldihydrazide were highl y soluble and readily gave tough films. Their performances as separati on membranes were examined in reverse osmosis, gas separation, and per vaporation (PV). The membranes showed a good performance in PV and wer e water permselective for aqueous alcohols and aprotic solutes, showin g to be very effective to break azeotropes with high separation factor s and to preferentially separate water from high concentration feeds, particularly in butanols and THF. Deviation from ideal flux, swelling degree, and some physicochemical parameters such as solubility paramet er, molar volume, and vapor pressure were correlated to the membrane p erformances in a wide range of feed concentrations of the above two so lute groups. (C) 1995 John Wiley & Sons, Inc.