Preparation And Characterizations Of Poly(vinyl butyral)/Caprolactam/Polyethylene Glycols Hydrophilic Flat‐sheet Membrane Through Thermally Induced Phase Separation

Abstract Poly(vinyl butyral)/caprolactam/polyethylene glycols hydrophilic flat‐sheet membranes were prepared via thermally induced phase separation (TIPS) for the first time. Poly(vinyl butyral) (PVB) was used as polymers,caprolactam (CPL) and polyethylene glycols (PEG) were used as mixed diluent. In all situations, the system occurs liquid‐liquid (L−L) phase separation to obtain asymmetric honeycomb structures. The effects of PVB concentration and molecular weight of PEG on the structure and performance of the flat‐sheet membranes were investigated in detail. Herein, the obtained PVB/CPL/PEG microporous membrane has some hydrophilicity and high BSA rejection ratio. Particularly, when the PVB concentration was 30 wt%, the PVB/CPL/PEG200 membrane achieved the highest bovine serum albumin (BSA) rejection of 85.36%. The prepared membrane had good antipollution performance, and the minimum adsorption amount of BSA was 4.94 g/m 2 . Those results show the PVB microporous membrane has great application prospects in the field of water treatment.