Effect of Coagulation Bath Conditions on the Properties of Cellulose Packaging Films From Ionic LiquidBMIMCl

摘要

By using natural softwood pulp with higher degree of polymerization (DP=1460)as cellulosesource and 1-butyl-3-methylimidazolium chloride([BMIM]Cl)ionic liquid as solvent, a novel cellulosepackaging film was prepared. The effects of coagulation types, concentration of coagulation and temperatureon the structure, mechanical property, permeability for oxygen and water vapor were measured. The investigationssuggest that the coagulation bath has great effect on the morphologies of the films, and the films preparedin [BMIM]Cl/water coagulation media show denser structure than those prepared in water, C2H5OHand DMSO media. When the [BMIM]Cl concentration in the coagulation bath increases, the tensile strengthincreases at first and then decreases. With increasing temperature of the coagulation bath, the tensile strengthdecreases slowly while the elongation at break of the films increases at first and then decreases. It was alsofound that both the oxygen permeability and the water vapor permeability of the films increase with the temperatureof coagulation bath and the concentration of [BMIM]Cl in the coagulation bath. The films preparedby using ionic liquid technology would be used in food packaging or other fields as a kind of green packagingmaterial.