Novel polyvinyl chloride ultrafiltration membranes blended with amphiphilic polyethylene glycol-block-poly(1, 2-dichloroethylene) copolymer for oily wastewater treatment

Abstract

Amphiphilic di-block copolymer consisting of polyethylene glycol (PEG) and poly(1,2-dichloroethylene) (PDCE) blocks was synthesized following the atom transfer radical polymerization (ATRP) procedure. The chemical structure of the obtained di-block copolymer PEG-b-PDCE was confirmed by different characterization techniques. Polyvinyl chloride (PVC) blend PEG-b-PDCE ultrafiltration (UF) membranes (PVC/PEG-b-PDCE) were prepared using the non-solvent induced phase separation (NIPS) technique and their characteristics were investigated as a function of the PEG-b-PDCE blending ratio in the casting solution. Water contact angle, permeate flux, and oil–water emulsion separation tests were performed to evaluate the hydrophilic character, permeability and anti-fouling membrane performance. It was found that the presence of PEG-b-PDCE copolymer affected the morphological structure of the membrane showing its good pore-forming capability. The oil rejection ability and anti-fouling properties of the blend membranes were improved by increasing the PEG-b-PDCE content up to 0.075 wt%. Compared to PVC membrane, the blend membrane prepared with 0.075 wt% PEG-b-PDCE exhibited about four times higher permeability with an excellent oil rejection factor, 98.78 %, indicating that the PVC/PEG-b-PDCE blend membranes have high potential in oily wastewater treatment.