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

Poly(amide-sulfonamide)s 1-4 were synthesized by low-temperature solut ion polycondensation of diamino monomers 5 and 6 with isophthaloyl chl oride/terephthaloyl chloride in N,N-dimethylacetamide (DMAc). The poly mers were adequately characterized for their properties. Membranes wer e fabricated from PASA 2 under different casting conditions by varying the casting solution composition, evaporation temperature and evapora tion time. The reverse osmosis (RO) tests for these membranes were per formed 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% a t a flux of over 11.9 cm per day. The RO performances of the membranes remained unchanged after treatment with dilute acid, alkali and oxidi zing agent.