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 (R t ), reversible fouling ratio (R r ), irreversible fouling ratio (R ir ) 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.