Novel crosslinked chitosan/poly(vinylpyrrolidone) blend membranes for dehydrating tetrahydrofuran by the pervaporation technique

Pervaporation separation has been attempted for dehydrating tetrahydrofuran (THF) from its aqueous mixtures using the novel blend membranes of poly(vinylpyrrolidone) (PVP) and chitosan (CS). Membranes were physically blended and crosslinked with glutaraldehyde as well as with sulfuric acid in methanol/sulfuric acid mixture bath to enhance their selectivity and mechanical strength properties. Membranes were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TGA) and X-ray diffractometer (X-RD) to assess their intermolecular interactions, thermal stability and crystallinity. Sorption studies were carried out in pure as well as in different compositions of THF + water mixtures to assess polymer–liquid interactions. The membrane exhibited a high selectivity of 1025 with a reasonably high water flux value of 0.0995 kg/m2 h at the azeotropic feed composition (94.31 wt.% of THF). Effect of operating parameters such as feed composition, membrane thickness and permeate pressure were evaluated.