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+–OC 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.

Graphical abstractSchematic diagram describing the equilibrium involved in the formation of a complex species from the interaction between a carbonyl group along the chitin macromolecular chain and Li+.Figure optionsDownload full-size imageDownload as PowerPoint slide