Preparation and stability of cellulose LiCl /DMAc solution
- ISSN: 02539721
The prepn. process and stability of cellulose LiCl /DMAc soln. were studied. The exptl. results showed that the cellulose subjected to activating treatment was added to the LiCl/DMAc solvent system, which was formed by dissolving LiCl into DMAc, and the resultant soln. was stirred for certain period of time at 100 DegC, then cooled down to room temp., and stirring continued for several hours, and so doing the uniform and transparent cellulose LiCl /DMAc soln. was obtained. It was also found that the greater the mass concn. of cellulose, the longer the time required for stirring both at high and room temp. Similarly, the greater the polymn. degree of cellulose, the more difficult the cellulose to dissolve. When LiCl contains crystal water, the cellulose only swells but insol. Only when the mass concn. of LiCl exceeds 6% can the cellulose be dissolved completely. In addn., the viscosity of cellulose LiCl /DMAc soln. at different temps. varying with time is tested, and it is shown that the soln. is very stable within 30 days at the temp. lower than 50 DegC, but remains stable only 15 h when heated to 100 DegC.