Method for producing cellulose ester acetate by using plant cellulose

[0030] Example 1

[0031] Weigh about 0.6 g of corn ear husk cellulose and 59.4 g of ionic liquid 1-allyl-3-methylimidazole chloride (AMIMCl), put them into a round bottom flask, heat it to 80°C in an oil bath, seal and stir strongly mechanically. 2h. A clear and transparent cellulose solution was obtained, and the concentration of the cellulose solution was 1% (mass fraction). At the same time, acetic anhydride (about 1.05ml) was added to the solution so that the molar ratio of acetic anhydride to the cellulose glucose unit was 3:1, and the reaction was carried out for 1 hour. After the reaction is completed, the product is repeatedly washed with water and placed in a vacuum drying cabinet, dried at 60°C for 24 hours; at the same time, the water in the washing liquid is removed by rotary evaporation to realize the recovery of the ionic liquid.

[0032] Weigh 0.1 g of the intermediate product, dissolve it in 3 ml of a dichloromethane-methanol mixed solvent (volume ratio of 9:1), dissolve it at room temperature for 2 hours, and then filter with suction to obtain a clear and transparent filtrate. After the filtrate is settled in n-hexane and filtered, the filter residue is collected, and the filter residue is cellulose acetate. The cellulose acetate was placed in a vacuum oven at 60°C for drying.

[0033] Example 2

[0034] Weigh about 0.6 g of corn stalk cellulose and 9.6 g of ionic liquid 1-ethyl-3-methylimidazole acetate (EMIMAc), put them into a round bottom flask, heat the oil bath to 60°C, seal and stir vigorously for 4 hours. . A clear and transparent cellulose solution was obtained, and the concentration of the cellulose solution was 4% (mass fraction). The temperature of the oil bath was raised to 90° C., and acetic anhydride (about 1.58 ml) was added to the solution at the same time, so that the molar ratio of acetic anhydride to cellulose glucose unit was 4.5:1, and the reaction was carried out for 8 hours.

[0035] Ionic liquid recovery and product separation were the same as in Example 1.

[0036] Example 3

[0037] Weigh about 0.6 g of peanut shell cellulose and 9.6 g of ionic liquid 1-butyl-3-methylimidazole chloride (BMIMCl), put them into a round-bottomed flask, heat the oil bath to 90° C., seal and stir vigorously for 6 hours. A clear and transparent cellulose solution was obtained, and the concentration of the cellulose solution was 4% (mass fraction). The temperature of the oil bath was raised to 120°C, and acetic anhydride (about 2.45 ml) was added to the solution at the same time, so that the molar ratio of acetic anhydride to the cellulose glucose unit was 7:1, and the reaction was carried out for 12 hours.

[0038] Weigh 0.1 g of the intermediate product, dissolve it in 5 ml of a dichloromethane-methanol mixed solvent (volume ratio of 9:1), dissolve it at room temperature for 4 hours, and then filter with suction to obtain a clear and transparent filtrate. After the filtrate is settled in n-hexane and filtered, the filter residue is collected, and the filter residue is cellulose acetate. The cellulose acetate was placed in a vacuum oven at 60°C for drying.