Formation of cellulose gel with ionic liquid and preparation of regenerated cellulose from the gel

POLY 496

Jun-ichi Kadokawa, kadokawa@eng.kagoshima-u.ac.jp, Masa-aki Murakami, and Yoshiro Kaneko, ykaneko@eng.kagoshima-u.ac.jp. Department of Nano-Structured and Advanced Materials, Graduate School of Science and Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima, 890-0065, Japan
Here, we report formation of gel from the solution of cellulose in an ionic liquid, 1-butyl-3-methylimidazolium chloride. When the solution was kept at room temperature for 7 days, it gradually became the gel form. The elemental analysis data of the isolated gel indicated that the molar ratio of the glucose units to the ionic liquid was calculated to be 1 : 2.48 and the gel contained 8.69 equivalents of water to the glucose units. The TG and XRD results suggested that the crystalline structure of cellulose was almost disappeared. However, existence of noncrystalline aggregates was assumed by the XRD data of the gel. These analytical data speculated that the gel was obtained by formation of the cellulose aggregates in the solution attributed to gradually absorbing water. The aggregates probably acted as cross-linking points in the gel. Furthermore, preparation of the regenerated cellulose from the gel was also carried out.