Poly(vinyl chloride) (PVC) hollow fiber ultrafiltration membranes prepared from PVC/additives/solvent

Abstract

Using poly(vinyl pyrrolidone) (PVP 40,000) or poly(ethylene glycol) (PEG) with different molecular weights (PEG 600, PEG 800, PEG 1000) as additives and N, N-dimethylacetamide (DMAc) as a solvent, asymmetric poly(vinyl chloride) (PVC) hollow fiber ultrafiltration membranes were prepared by phase inversion technique from 14 to 20 wt.% solids including PVC and additives. The 95/5 DMAc/water and pure water were used as the bore fluid to investigate the effect of gelation bath. The dope solutions, membrane structure, separation performance and mechanical properties of PVC hollow fiber membranes were studied. The membrane structures of PVC hollow fiber membranes including external surface, internal surface and cross-section were characterized by scanning electron microscopy (SEM), and the mechanical properties of PVC hollow fiber membranes were discussed. It was found that using PVP or PEG as additives can increase the membrane porosity and enhance the permeation flux by changing the membrane morphology. Three kinds of proteins having different molecular weights were applied for the measurement of rejection. Based on the experimental results, pure water permeation fluxes of PVC/additives/DMAc hollow fiber membranes might reach 100–200 l/(m 2 h bar) while the molecular weight cut-off of PVC hollow fiber membranes is approximately 50,000.