Method for preparing full acetylation cellulose

A technology of full acetylation and cellulose, applied in the field of preparation of full acetylated cellulose, can solve the problems of lack of cellulose transesterification catalyst, difficulty in realizing cellulose full acetylation, aggravating cellulose degradation, etc., and achieve product purification Simple and easy to operate, improve the efficiency of transesterification reaction, and easy to operate

Active Publication Date: 2014-02-05
SOUTH CHINA UNIV OF TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The use of these acidic reagents not only requires high equipment, but also often leads to serious degradation of cellulose. At the same time, when acetic anhydride or acetyl chloride is used as an acylating reagent, the corresponding small molecule by-product acetic acid or hydrochloric acid is generated, and the purification of the product is cumbersome and acidic. By-products further exacerbate cellulose degradation
The existing transesterification to prepare cellulose acetate can be carried out under alkaline conditions, but the efficiency is low. There has been no efficient cellulose transesterification catalyst, and it is difficult to achieve full acetylation of cellulose

Method used

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  • Method for preparing full acetylation cellulose
  • Method for preparing full acetylation cellulose

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Embodiment 1

[0025] The cellulose of this embodiment is fully acetylated under efficient and mild conditions, and its specific preparation process is as follows:

[0026] Step 1. Disperse 0.1g of linter cellulose into dimethyl sulfoxide (DMSO) to obtain a cellulose suspension, the mass volume ratio of cellulose to DMSO is 1g:40mL;

[0027] Step 2. join acylating reagent IPA and catalyzer DBU in the cotton linter cellulose suspension obtained in step 1, the mol ratio of the anhydroglucose unit of IPA and cotton linter cellulose is 4:1, DBU and acyl The volume ratio of the reagent IPA is 1:5, and the esterification reaction is carried out at 60°C under air-isolated conditions. The reaction time is 15 hours, and the reaction process is kept uniformly stirred;

[0028] Step 3. After the esterification reaction is completed, pour the reaction solution into 100mL of a mixture of ethanol and water (volume ratio: 1:2) to terminate the reaction, stir well and filter, and wash the precipitate with e...

Embodiment 2

[0031] The cellulose of this embodiment is fully acetylated under efficient and mild conditions, and its specific preparation process is as follows:

[0032] Step 1. Disperse 0.1g of eucalyptus cellulose into dimethyl sulfoxide (DMSO) to obtain a cellulose suspension, and the mass volume ratio of cellulose to DMSO is 1:20 (g / mL);

[0033] Step 2. join acylating reagent IPA and catalyst DBU in the eucalyptus wood cellulose suspension that obtains in step 1, the mol ratio of IPA and cellulose anhydroglucose unit is 6:1, the volume of DBU and acylating reagent IPA The ratio is 1:10, and the esterification reaction is carried out at 110°C under air-isolated conditions, the reaction time is 6h, and the reaction process is kept uniformly stirred;

[0034] Step 3. After the esterification reaction is completed, pour the reaction solution into 100mL of a mixture of ethanol and water (volume ratio: 1:2) to terminate the reaction, stir well and filter, and wash the precipitate with etha...

Embodiment 3

[0037] The cellulose of this embodiment is fully acetylated under efficient and mild conditions, and its specific preparation process is as follows:

[0038] Step 1. Disperse 0.1g of bagasse cellulose into dimethyl sulfoxide (DMSO) to obtain a cellulose suspension, and the mass volume ratio of cellulose to DMSO is 1:10 (g / mL);

[0039] Step 2. join acylating reagent IPA and catalyst DBU in the eucalyptus wood cellulose suspension that obtains in step 1, the mol ratio of IPA and cellulose anhydroglucose unit is 10:1, the volume of DBU and acylating reagent IPA The ratio is 1:20, and the esterification reaction is carried out at 130°C under air-isolated conditions, the reaction time is 2h, and the reaction process is kept uniformly stirred;

[0040] Step 3. After the esterification reaction is completed, pour the reaction solution into 100mL of a mixture of ethanol and water (volume ratio: 1:2) to terminate the reaction, stir thoroughly and filter, and wash the precipitate with ...

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Abstract

The invention discloses a method for preparing full acetylation cellulose. The method is as below: dispersing cellulose into dimethyl sulfoxide to obtain a cellulose suspension; then adding an acylation agent isopropenyl acetate and a catalyst 1,8-diazabicyclo [5,4,0] undec-7-ene in to the cellulosic suspension; conducting an esterification reaction in the conditions of isolation from air and stirring at the temperature of 60-130 DEG C for 2-15 h; and carrying out sedimentation treatment on the obtained solution, collecting precipitates, washing and drying the precipitates to obtain full acetylation cellulose. The method provided by the invention employs a polar solvent DMSO as a medium, and isopropenyl acetate as an acylation agent, and carries out acetylation of cellulose through the esterification reaction with mild conditions; and the catalyst 1,8-diazabicyclo [5,4,0] undec-7-ene effectively improves the transesterification efficiency. The method has simple operation, realizes high degree of acetylation and can effectively avoid the degradation of cellulose and equipment corrosion.

Description

technical field [0001] The invention relates to the technical field of renewable resources, in particular to the preparation of cellulose derivatives, in particular to a method for preparing fully acetylated cellulose. Background technique [0002] Wood fiber has many advantages such as large quantity and low price, renewable, short regeneration cycle, biodegradable, and environment-friendly. Compared with non-renewable resources such as petroleum and coal, the conversion of renewable resources such as wood fiber into high calorific value energy, new industrial raw materials, fine chemicals, food, medicine and feed has inevitably become a future development trend. Many countries Especially developed countries have listed the conversion and utilization of wood fiber and other renewable resources as a major strategy for economic and social development. [0003] Due to the severe inhomogeneity of the structural properties of the various components of lignocellulosic, one of th...

Claims

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Application Information

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IPC IPC(8): C08B3/06C08B3/28
Inventor 刘传富陈超羿孙润仓张雪琴陈铭杰鲍登山
Owner SOUTH CHINA UNIV OF TECH
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