SYNTHESIS, CHARACTERIZATION AND REVERSE-OSMOSIS PERFORMANCE OF POLY(AMIDE SULFONAMIDE)S

Poly(amide-sulfonamide)s 1-4 were synthesized by low-temperature solution polycondensation of diamino monomers 5 and 6 with isophthaloyl chloride/terephthaloyl chloride in N,N-dimethylacetamide (DMAc). The polymers were adequately characterized for their properties. Membranes were fabricated from PASA 2 under different casting conditions by varying the casting solution composition, evaporation temperature and evaporation time. The reverse osmosis (RO) tests for these membranes were performed with 1000 ppm aqueous sodium chloride feeds at 20 to 40 kg cm-2 operating pressure. Membranes showed salt rejections of up to 97.9% at a flux of over 11.9 cm per day. The RO performances of the membranes remained unchanged after treatment with dilute acid, alkali and oxidizing agent.