| Cellulose, a natural renewable resource with high value of development and application, is widely studied in recent years. Common solvents cannot dissolve cellulose, so the homogeneous derivatization and further processing require special solvent system to complete. An ionic liquid is a novel solvent with excellent solubility of cellulose, and can provide homogeneous reaction environment. In this article we added double-bond-containing group into cellulose by esterification in ionic liquids, and obtained a thermosensitive gel in further reaction. The results of experiment show that:1. Ionic liquid 1-Allyl-3-methylimidazole chloride (AmimCl) has a good performance in dissolving cellulose. Cellulose of about 500 degree of polymerization can be completely dissolved at 80℃ in 1 hour without any pretreatment. The degree of dissolution can reach 10wt%.2. Cellulose can be derivatized in ionic liquids, a series of esterification products with different degrees of substitution are obtained by changing the experimental conditions. By comprehensive analysis in degree of substitution and purity of product, we find out the relatively appropriate reaction condition of cellulose and acryloyl chloride is under 60℃ in 2 hour with 1:5 molar ratio of raw material, in which cellulose acrylate of 1.76 degree of substitution can be obtained. According to the regular pattern of the reaction, cellulose is also derivatized with cinnamoyl chloride and cellulose cinnamate is successfully obtained.3. A thermosensitive gel can be obtained by copolymerization of cellulose acrylate and Poly(Ethylene Glycol) Acrylate (PEGA), and it has Lower Critical Solution Temperature (LCST) at 65℃, verified by experiment of DSC, ESR and UV-Visible transmittance. |
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