Preparation and Pervaporation Performance of Chitosan-Poly(methacrylic acid) Polyelectrolyte Complex Membranes for Dehydration of 1,4-Dioxane

摘要

Polyelectrolyte complex (PEC) membranes composed of chitosan (CS) and poly(methacrylic acid) (PMAA) were prepared by mixing the polymer solutions in different ratios. The chemical interaction and crystallinity of the resulting PEC membranes were respectively analyzed by Fourier transform infrared spectroscopy (FTIR) and wide-angle Xray diffraction (WAXD). Differential scanning calorimetry (DSC) was used to characterize the thermal properties of the membranes. The membranes thus obtained were subjected to pervaporation (PV) separation of water-dioxane mixtures. Among the PEC membranes, membrane containing 30 wt% ratio of PMAA (M-3) exhibited the highest separation selectivity of 840 with a flux of 12.07 x 10(-2) kg/m(2)h at 30 degrees C at 15 wt% of water in the feed. By the incorporation of NaY zeolite into PEC up to 5 wt%, we have been able to overcome the trade-off phenomenon existing between flux and selectivity in PV process. From the temperature dependent diffusion and permeation values, the Arrhenius activation parameters were estimated. The resulting activation energy values obtained for water permeation (E-pw) are much lower than those of dioxane permeation (E-po), suggesting that the developed membranes have higher separation efficiency for water-dioxane system. Based on the heat of sorption (Delta H-s) values, the mode of sorption was discussed. (C) 2016 Society of Plastics Engineers