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Purification process of glycolide

A glycolide and process technology, applied in the field of glycolide purification technology, can solve the problems of low purification yield, high energy consumption, long melting crystallization process cycle and the like, and achieves improvement of purity, reduction of acid value, and improvement of purity. Effect

Pending Publication Date: 2022-02-08
内蒙古久泰新材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In order to remove the above-mentioned by-products and improve the purity of glycolide, currently commonly used purification methods include recrystallization, rectification, and melt crystallization. Recrystallization is difficult to achieve continuous operation; rectification will cause Glycolide undergoes a polymerization reaction, and the purification yield is low; the melt crystallization method has a long treatment period and high energy consumption, which is not suitable for industrial applications

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] A purification process of glycolide, comprising the following steps:

[0024] (1) Crude product dissolution: 120g of crude glycolide with an acid value of 620mmol / kg and a purity of 92.6% was dissolved in 2000ml of dichloromethane, stirred and dissolved, and the temperature was controlled at about 25°C to obtain dissolved glycolide. solution, and the entire dissolution process remains sealed;

[0025] (2) Liquid-liquid extraction: Add 600ml of ultrapure water to the solution obtained in the dissolution of the crude product in step (1), fully stir for 2 minutes, and let it stand for 2 minutes to obtain a mixed solution, so that glycolic acid and a small amount of ethanol in the by-product Acid dimers, glycolic acid trimers, and trace glycolic acid tetramer impurities are transferred to the water phase; the contact time between the solution and ultrapure water does not exceed 1 hour, and the temperature of ultrapure water does not exceed 10°C. In this way, hydrolysis of ...

Embodiment 2

[0031] A purification process of glycolide, comprising the following steps:

[0032] (1) Crude product dissolution: 120g of crude glycolide with an acid value of 620mmol / kg and a purity of 92.6% was dissolved in 2000ml of ethyl acetate, stirred and dissolved, and the temperature was controlled at about 25°C to obtain dissolved glycolide. solution, and the entire dissolution process remains sealed;

[0033] (2) Liquid-liquid extraction: Add 600ml of ultrapure water to the solution obtained in the dissolution of the crude product in step (1), fully stir for 2 minutes, and let it stand for 2 minutes to obtain a mixed solution, so that glycolic acid and a small amount of ethanol in the by-product Acid dimers, glycolic acid trimers, and trace glycolic acid tetramer impurities are transferred to the water phase; the contact time between the solution and ultrapure water does not exceed 1 hour, and the temperature of ultrapure water does not exceed 10°C. In this way, hydrolysis of gl...

Embodiment 3

[0039] A purification process of glycolide, comprising the following steps:

[0040] (1) Crude product dissolution: 120g of crude glycolide with an acid value of 620mmol / kg and a purity of 92.6% was dissolved in 2000ml of butyl acetate, stirred and dissolved, and the temperature was controlled at about 25°C to obtain dissolved glycolide. solution, and the entire dissolution process remains sealed;

[0041] (2) Liquid-liquid extraction: Add 600ml of ultrapure water to the solution obtained in the dissolution of the crude product in step (1), fully stir for 2 minutes, and let it stand for 2 minutes to obtain a mixed solution, so that glycolic acid and a small amount of ethanol in the by-product Acid dimers, glycolic acid trimers, and trace glycolic acid tetramer impurities are transferred to the water phase; the contact time between the solution and ultrapure water does not exceed 1 hour, and the temperature of ultrapure water does not exceed 10°C. In this way, hydrolysis of gl...

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PUM

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Abstract

The invention discloses a purification process of glycolide, which comprises the steps of firstly, dissolving a crude product to dissolve glycolide in crude glycolide in an organic solvent; then through liquid-liquid extraction, transferring glycollic acid, a small amount of glycollic acid dimer and glycollic acid trimer and a trace quantity of glycollic acid tetramer impurities in byproducts into an extraction agent phase; then through two-phase separation, removing impurities dissolved in the extraction agent along with the separated extraction agent phase; after inorganic salt (anhydrous magnesium sulfate or anhydrous sodium sulfate) or a molecular sieve is added into the separated organic phase to adsorb water, removing the inorganic salt and the molecular sieve after water absorption and impurities such as glycollic acid dimer, glycollic acid trimer and glycollic acid tetramer which are not dissolved in the extraction agent through small-filter-diameter filter cloth, thereby achieving the effects of dehydration and impurity removal, improving the purity of the glycolide product, and reducing the acid value of the glycolide product; and finally, distilling, concentrating, centrifuging and drying to obtain a high-purity glycolide product of which the purity is greatly improved.

Description

Technical field: [0001] The invention relates to the field of chemical industry, in particular to a purification process of glycolide. Background technique: [0002] Polyglycolide (PGA), also known as polyglycolic acid, is a highly crystalline, biodegradable aliphatic polymer, non-toxic, non-irritating, biodegradable, absorbable, high strength, good plasticity, easy to It has the characteristics of processing and molding, and is mainly used in the fields of surgical sutures and other fields. Glycolide is used as a raw material for preparing polyglycolide, and its purity will directly affect the product quality of polyglycolide. [0003] Glycolide is usually obtained by thermal cracking of low-molecular-weight polyglycolic acid, but by-products such as glycolic acid, glycolic acid dimer, trimer, tetramer, and water are produced during the cracking process. In order to remove the above-mentioned by-products and improve the purity of glycolide, currently commonly used purific...

Claims

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Application Information

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IPC IPC(8): C07D319/12
CPCC07D319/12
Inventor 徐德芳林祥权崔涛王建其王东芳丁志刚何春阳崔轶钧王总镇曹营房
Owner 内蒙古久泰新材料有限公司