Viscosity-temperature behavior of chitin solutions using lithium chloride/DMA as solvent

Solutions of chitin in Li+/N,N-dimethylacetamide systems were studied via viscometry, using LiCl concentrations of 3% and 5% (m/v) and chitin concentrations ranging from 0.075 to 0.375 g L-1. The reduced viscosity number versus concentration plot showed a minimum that was related to the formation of Li+-O=C complex moieties along chitin macromolecular chains. Viscosity behavior was affected by temperature according to the Eyring model: concentration dependence of flow enthalpy of activation was correlated to polymer-polymer interactions and flow entropy of activation to the stiffness of the complexed chitosan macromolecular chain. (C) 2011 Elsevier Ltd. All rights reserved.