The investigation of the influence of water and temperature on the LiCl/DMAc/cellulose system

In this study the influence of temperature and water on the dissolution of cellulose in the solvent system LiCl/DMAc is examined. The phase diagrams performed in the system without water show that higher amounts of cellulose can be dissolved at 5 °C, whereas at 25 °C smaller concentrations of LiCl in DMAc are sufficient to solubilize some cellulose. Furthermore a relation between the concentration of LiCl and the maximum possible water content is established. The analysis shows that the ratio between water and LiCl in the mixture has to be smaller than 2∶1. Otherwise complete dissolution of cellulose cannot be achieved. The relation between LiCl and anhydroglucose unit is examined as well. The results imply the breakdown of two hydrogen bonds during the solution process because the interaction of two LiCl/DMAc complexes with one glucose unit is required. The viscosity of the system is investigated also but no special behavior is observed.