Amphiphilic PPESK-graft-P(PEGMA) copolymer for surface modification of PPESK membranes

Amphiphilic graft copolymer consisting of poly(phthalazinone ether sulfone ketone) (PPESK) backbones and poly-(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA)) side chains was synthesized by atomic transfer radical polymerization (ATRP). PPESK resin was beforehand chloromethylated, and the obtained chloromethylated PPESK (CMPPESK) containing benzyl chloride groups was used as macro-initiators to graft hydrophilic P(PEGMA) chains. The synthesized products were characterized by 1H NMR, Fourier transform infrared (FT-IR) spectroscopy and thermo-gravimetric analysis (TGA). The obtained PPESK-g-P(PEGMA) graft copolymer was used as an additive in the preparation of PPESK ultrafiltration membranes by phase inversion technique. X-ray photoelectron spectroscopy (XPS) analysis indicated that hydrophilic P(PEGMA) chains were excluded to membrane surface during membrane formation. Water contact angle measurements and protein filtration experiments showed that the surface hydrophilicity and the anti-fouling ability of PPESK membranes were significantly improved due to the surface enrichment of P(PEGMA) chains. Consequently, a hydrophilic surface modification for PPESK membrane was achieved by a simple single-step blending method.