Preparation of a novel sulfonated polyphenlene sulfone with flexible side chain for ultrafiltration membrane application

In order to mitigate the selectivity-permeability trade-off for ultrafiltration membranes, a series of polyphenylene sulfone (PPSU) with flexible negative charged sulfonated side chains (SPPSU-SC) were synthesized applied in ultrafiltration (UF) field. And tests results showed that the ultrafiltration performance was enhanced greatly. In short, the water flux increased to 380 L·m−2·h−1 at the sulfonation degree of 20%, which was as two and a half times high as PPSU membranes. However, the membrane SPPSU-SC20 still held a relatively high BSA rejection of 91.6%, which should be attributed to the enrichment of negative charged sulfonic groups on the membrane surface. More importantly, the antifouling properties were also promoted. The total fouling ratio (Rt), reversible fouling ratio (Rr), irreversible fouling ratio (Rir) and flux recovery ratio (FRR) were all improved to some degree. Besides, compared to the main-chain sulfonated PPSU with the sulfonation degree of 20% (SPPSU-MC20) membranes, SPPSU-SC20 had a better separation structure caused by better phase separation during the membrane preparation period at the sane high sulfonation degree. In a word, the results showed that side-chain sulfonated PPSU possessed a potential bright horizon in ultrafiltration field.