Crosslinked chitosan membranes: characterization and study of dimethylhydrazine dehydration by pervaporation

Crosslinked chitosan membranes were synthesized using glutaraldehyde and characterized by infra-red (IR) and wide-angle X-ray diffraction (WAXD) spectroscopic methods. The membranes were applied for the pervaporation-based dehydration of the highly hazardous and hypergolic unsymmetrical dimethylhydrazine liquid propellant. The characterization techniques were an efficient tool in identifying polymer–liquid interaction sites and the separation mechanisms involved. The crosslinked polymer was found to have good potential for the separation of the aqueous azeotrope of the propellant (20 wt%) and its enrichment to >90% purity. An equilibrium sorption study examined the preferential affinity of the membrane amongst the two penetrating liquids. The pervaporation performance of the membrane was evaluated by varying the experimental parameters of feed composition, membrane thickness and permeate pressure, and found to be promising. © 2001 Society of Chemical Industry