Blended cellulose/chitin membranes prepared by co-solvent method for pervaporation of water-butanol solutions

Blended cellulose/chitin membranes with various mixing ratios were successfully prepared by a co-solvent method from cellulose carbamate (CC) and chitin (CT) in an alkali/urea aqueous system. The blended solutions were characterized by rheological measurements. Blending CT with CC effectively enhanced the thermal stability of the as-obtained CT solution. The prepared membranes were characterized by FTIR, C NMR, XRD, TG, XPS, SEM, AFM, Raman, and tensile tests. CC and CT were homogeneously distributed in the blended membranes which clearly demonstrates the compatibility between the two polymers. The blended membrane with 20 wt% CT exhibited outstanding thermal stability and mechanical properties. Furthermore, all membranes were subjected to pervaporation tests. The blended membranes demonstrated excellent separation performance in pervaporation of water (6 wt%)-butanol (94 wt%) mixtures. Among all the membranes, the blended membrane with 20 wt% CT loading demonstrated the best pervaporation performance, achieving a permeation flux of 414.4 ± 40.1 g m h and a separation factor of 798.9 ± 10.5. In addition, the membranes showed stable separation performance over 3 days of continuous pervaporation. Therefore, this study provides guidance and reference for the design of high-efficiency pervaporation polymer blended membranes.