Poly(4-vinylpyridine) and poly(vinyl acetate -co-4-vinylpyridine) grafted polyvinyl chloride membranes for removal of tetrahydrofuran from water by pervaporation

摘要

The organophilic character of polyvinyl chloride (PVC) membrane was significantly improved by graft copolymerization with i) different wt. % of 4-vinylpyridine (4VP) and ii) 4VP and vinyl acetate (VA) taken at different molar ratios. The graft copolymers were further filled with organo clay in situ during polymerization. Membranes prepared from these unfilled and organo clay filled polymers were characterized by FTIR, NMR, XRD, SEM, TEM, EDAX, DTA-TGA and mechanical properties. These membranes were used for sorption and pervaporation of 0.5-20 wt% of tetrahydrofuran (THF) from water. The effect of the synthesis and the process variables on sorption and pervaporation were studied with fitting of the experimental sorption and pervaporation data to the engaged species induced clustering (ENSIC) and resistance in series model, respectively. The experimental data showed close fitting to the models. The PVC membrane grafted with poly(4VP) and poly (4VP-co-VA), each containing 1.5 wt% organo clay showed a flux/THF selectivity of 0.215 kg/m(2)h/97 and 233 kg/m(2)h /105, respectively for 12.5 wt% THF in feed at 30 degrees C.