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Preparation method of hydroxypropyl methylcellulose acetate succinate in novel solvent system

A technology of hydroxypropylmethylcellulose and hydroxypropylmethyl acetate, which is applied in the field of preparation of hydroxypropylmethylcellulose succinate in a new solvent system, can solve the problem of the deterioration of product storage performance and the impact of acetic acid Product quality and performance, non-recyclable solvents and other issues, to achieve the effect of lowering the temperature, shortening the reaction time, and reducing the residual acetic acid content

Inactive Publication Date: 2012-10-03
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] However, in the process of industrialization, the use of the original system has many disadvantages, such as strong corrosion to equipment, non-recyclable solvents, residual acetic acid that makes product storage performance worse, etc.
Moreover, the post-processing stage of the product is cumbersome and requires a large amount of water to wash to meet the requirements. At the same time, the product is also embedded in acetic acid, which seriously affects the quality and performance of the product.

Method used

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  • Preparation method of hydroxypropyl methylcellulose acetate succinate in novel solvent system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) Esterification reaction: Add 10g of raw material hydroxypropyl methylcellulose, 80mL of solvent acetone, 8g of esterification agent succinic anhydride and 40mL of acetic anhydride, and 0.5g of catalyst 4-dimethylaminopyridine into the autoclave. The mixed system was reacted for 2 hours under the conditions of a pressure of 2 bar and a temperature of 85° C., and then the reaction was stopped.

[0027] (2) Product extraction: After the esterification reaction is completed, lower it to normal temperature, add an appropriate amount of water to the product, precipitate the product, wash it with boiling water for 3 times until it is odorless, dry it at 60°C, and distill and separate acetone to obtain the product , after detection, the content of acetyl group is 8.2% (mass fraction, the same below), and the content of succinyl group is 12.5% ​​(mass fraction, the same below).

Embodiment 2

[0029] (1) Esterification reaction: Add 10g of raw material hydroxypropyl methylcellulose, 80mL of solvent acetone, 9g of succinic anhydride, and 1g of catalyst 4-dimethylaminopyridine into the autoclave. React at 85°C for 30 minutes, then add 40 mL of acetic anhydride into the autoclave, keep the original reaction temperature constant, continue the reaction for 2 hours, and then stop the reaction.

[0030] (2) Product purification: After the esterification reaction, cool down to room temperature, add an appropriate amount of dilute hydrochloric acid to the container to precipitate the product, filter under normal pressure, wash the product with boiling water for 3 times until it is odorless, and then dry it in an oven at 60°C , acetone was separated by distillation to obtain the target product, and the acetyl group content was found to be 8.9% after detection , The succinyl content is 13.2%.

Embodiment 3

[0032] (1) Esterification reaction: Add 10g of raw material hydroxypropyl methylcellulose, 500mL of solvent acetone, 8g of succinic anhydride, 1g of catalyst 4-dimethylaminopyridine, and 60mL of acetic anhydride into the autoclave. It was reacted for 4 hours under the conditions of 5 bar and 95° C., and the reaction was stopped.

[0033] (2) Product purification: After the esterification reaction, cool down to room temperature, add an appropriate amount of water to the container to precipitate the product, filter under normal pressure, wash the product with boiling water for 3 times until it is odorless, and then dry it in an oven at 60°C , acetone was separated by distillation to obtain the target product, and the acetyl content was 9.4% and the succinyl content was 11.9%.

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Abstract

The invention discloses a preparation method of hydroxypropyl methylcellulose acetate succinate in a novel solvent system. The preparation method comprises the steps as follows: adding hydroxypropyl methylcellulose, inert solvents, esterifying agents and catalyzers into a reaction vessel, and heating and stirring for esterification; lowering the temperature to the room temperature after esterification, and adding precipitants for settling out products; washing the products, and distilling to separate the inert solvents, thereby obtaining hydroxypropyl methylcellulose acetate succinate. According to the invention, the preparation method has the advantages that the reaction condition is mild, the reaction rate is high, the solvents can be recovered, and the post processing for the products is simple.

Description

technical field [0001] The invention belongs to the field of cellulose ether ester synthesis, in particular to a preparation method of hydroxypropyl methylcellulose succinate in a novel solvent system. Background technique [0002] Hydroxypropyl methylcellulose acetate succinate is white to pale yellow powder or granules, with a true density of 1.27-1.30g / cm 3 , Soluble in acetone, methanol, ethanol-dichloroethane, ethanol-water mixed solvent, insoluble in ether and water. [0003] Hydroxypropyl methylcellulose acetate succinate is a mixed diester of non-ionic cellulose ethers, which contains four groups of hydroxypropoxyl, methoxyl, acetyl, and succinyl, so its The properties show different solubility properties with different group content. Hydroxypropoxy is a hydrophilic group, and its presence makes the cellulose ether ester water-soluble; methoxy is a hydrophobic group, and its presence makes it soluble in certain organic solvents. It is beneficial to the preparation...

Claims

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Application Information

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IPC IPC(8): C08B13/00
Inventor 付时雨张亮亮谢传龙
Owner SOUTH CHINA UNIV OF TECH
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