Properties and pervaporation characteristics of chitosan-poly(N-vinyl-2-pyrrolidone) blend membranes for MeOH-MTBE

Clear blends of chitosan with poly(N-vinyl-2-pyrrolidone) (PVP) made from a queous solutions appear to be miscible from visual appearance. infrared (IR ) spectra used to investigate the carbonyl-hydroxyl hydrogen bonding in the blends indicated compatibility; of two polymers on a molecular level. The IR spectra were also used to determine the interaction change accessing wit h increasing temperature and indicated that a significant conformational ch ange occurred. On the other hand, the blend membranes were evaluated for se paration of methanol from methyl tert-butyl ether. The influences of the me mbrane and the feed compositions were investigated. Methanol preferentially permeates through all the tested membranes, and the partial flux of methan ol significantly increase with. the poly(N-vinyl-2-pyrrolidone) content inc reasing. The temperature dependence of pervaporation performance indicated that a significant conformational change occurred with increasing temperatu re. Combined with the IR results, the pervaporation properties are in agree ment with characteristics of interaction between chain- chain within the bl end membranes. (C) 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1452-1 458, 1999.