Blended PVC/PVC-g-PEGMA ultrafiltration membranes with enhanced performance and antifouling properties

To improve the performance of poly(vinyl chloride) (PVC) membranes, we synthesized the amphiphilic copolymer PVC-graft-poly(ethylene glycol) methyl ether methacrylate (PVC-g-PEGMA) via atom transfer radical polymerization (ATRP). We then fabricated PVC/PVC-g-PEGMA blended ultrafiltration membranes for the first time. The effect of the amount of PVC-g-PEGMA from 5 to 20 wt.% on the PVC membrane properties was systematically investigated. The successful synthesis of PVC-g-PEGMA was confirmed by the results of nuclear magnetic resonance (H-1 NMR), and Fourier transform infrared spectroscopy (FTIR). With the increase in the amount of the PVC-g-PEGMA additive from 0 to 20 wt.%, we found that (1) the surface oxygen content of the membrane increased from 3.20% to 9.31%; (2) the membrane surface pore size and pore density decreased; (3) the hydrophilicity and pure water flux of the membrane improved, but they plateaued, even slightly decreasing after the addition of 15 wt.% PVC-g-PEGMA; (4) the sodium alginate (SA) rejection ratios of all PVC/PVC-g-PEGMA blended membranes were higher than 90%; and (5) all blended PVC membranes exhibited higher flux recovery ratios (FRRs) than the pure PVC membrane; in particular, the FRR increased by 89% when 10 wt.% PVC-g-PEGMA was added. These results indicated the enhanced antifouling properties of PVC/PVC-g-PEGMA blended ultrafiltration membranes.