Enhanced performances of chlorinated polyvinyl chloride (CPVC) ultrafiltration membranes by styrene-maleic anhydride copolymer

To enhance the performances of the CPVC ultrafiltration membranes, herein, styrene-maleic anhydride copolymer (SMA), an amphiphilic copolymer, was used to blend with CPVC to adjust the microstructures of membranes. The pure CPVC and SMA/CPVC composite ultrafiltration membranes were prepared by a non-solventinduced phase inversion process. It has been proved that SMA and CPVC were partially compatible according to the rheological behavior of casting solution, DSC, FT-IR and SEM. SMA changed the phase separation mechanism and the pore structure of the composite membranes, and significantly increased the porosity. According to the results of ATR-FTIR, EDS and XPS analysis, intact anhydride groups existed on the surface of the composite membranes, which enhanced the permeability of membranes. The SMA/CPVC composite ultrafiltration membranes with 2 wt% SMA exhibited superior pure water flux (459.85 L/m(2).h), protein rejection (97.2%) and permeability flux (140.69 L/m2.h) compared with the neat CPVC membrane (248.97 L/m(2).h, 74.5%, 74.14 L/m(2).h, respectively) at 0.1 MPa. Moreover, the flux recovery ratio increased from 55.32% to 92.68% and irreversible fouling index decreased from 42.51% to 5.00%. Importantly, the antifouling mechanism of the SMA/ CPVC ultrafiltration membrane was discussed in detail.

Automated summary

Blending styrene-maleic anhydride copolymer (SMA) with CPVC can improve the performance of ultrafiltration membranes by adjusting microstructures, increasing pure water flux and permeability, reducing irreversible fouling index, and enhancing flux recovery ratio.