Preparation method polyglycolic acid oligomer

A technology of polyglycolic acid and oligomers, which is applied in organic chemistry and other fields, can solve the problems of high impurities, low yield and purity of glycolide, and achieve the effects of low impurity content, uniform molecular weight distribution, and high yield

Inactive Publication Date: 2016-02-10
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] The technical problem solved by the present invention is that when the polyglycolic acid oligomer prepared in the prior art is used to produce glycolide, there are many impurities, and the yield and purity of the glycolide obtained are relatively low. Preparation method of polyglycolic acid oligomer of glycolide, which is prepared by polycondensation of glycolic acid

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] After adding 400g of glycolic acid crystals and 2g of stannous octoate catalyst into the reactor, the temperature was raised from room temperature to 90°C. After the solid was completely dissolved, the temperature was raised to 112°C to start prepolymerization. After 1 hour of prepolymerization, the temperature was raised to 140°C. After anhydrous distilled off, the system was kept at temperature and vacuum was started. The vacuum degree of this process is controlled at 3KPa. After the anhydrous was distilled off, the system was kept in this state and continued to react for 1 h to obtain 311 g of polyglycolic acid oligomer.

[0026] The obtained polyglycolic acid oligomer was reacted at a reaction temperature of 260° C. and a vacuum of 0.5 KPa to prepare glycolide, and the reaction was stopped when no glycolide evaporated to obtain 265 g of glycolide crude product. The yield was 87%. The molar purity of glycolide is 59%.

Embodiment 2

[0028] After adding 400g of glycolic acid crystals and 2g of stannous octoate catalyst into the reactor, the temperature was raised from room temperature to 90°C. After the solid was completely dissolved, the temperature was raised to 112°C to start prepolymerization. After 1 hour of prepolymerization, the temperature was raised to 160°C. After anhydrous distilled off, the system was kept at temperature and vacuum was started. The vacuum degree of this process is controlled at 3KPa. After the anhydrous was distilled off, the system was kept in this state and continued to react for 1 hour to obtain 308 g of polyglycolic acid oligomer.

[0029] The obtained polyglycolic acid oligomer was reacted at a reaction temperature of 260° C. and a vacuum of 0.5 KPa to prepare glycolide, and the reaction was stopped when no glycolide was evaporated to obtain 268 g of glycolide crude product. The yield was 88%. The molar purity of glycolide is 70%.

Embodiment 3

[0031]After adding 400g of glycolic acid crystals and 2g of stannous octoate catalyst into the reactor, the temperature was raised from room temperature to 90°C. After the solid was completely dissolved, the temperature was raised to 112°C to start prepolymerization. After 1 hour of prepolymerization, the temperature was raised to 180°C. After anhydrous distilled off, the system was kept at temperature and vacuum was started. The vacuum degree of this process is controlled at 3KPa. After the anhydrous was distilled off, the system was kept in this state and continued to react for 1 h to obtain 300 g of polyglycolic acid oligomer.

[0032] The obtained polyglycolic acid oligomer is reacted at a reaction temperature of 260° C. and a vacuum of 0.5 KPa to prepare glycolide, and the reaction is stopped when no glycolide is evaporated to obtain 265 g of glycolide crude product. The yield is 87%. The molar purity of glycolide is 73%.

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Abstract

The invention relates to a preparation method of a polyglycolic acid oligomer. The preparation method is mainly used for solving problems of the prior art that the content of impurities is large when the polyglycolic acid oligomer prepared via a conventional method is used for producing glycolide, and glycolide yield and purity are low. The preparation method comprises following steps: (1) normal pressure condensation polymerization, wherein glycollic acid crystals are subjected to staged reaction at normal pressure in the presence of a condensation catalyst or an ester exchange catalyst, wherein normal pressure prepolymerization is carried out for 0.5 to 10h at a temperature maintained to be higher than the melting point of glycollic acid and lower than the boiling point of glycollic acid at a step of first stage prepolymerization, and condensation reaction or ester exchange is carried out at 112 to 220 DEG C until no water is evaporated for a step of second stage condensation polymerization so as to obtain a molten glycollic acid oligomer; and (2) decompression polycondensation; and (3) strengthened polycondensation. The preparation method is capable of solving the problems above preferably, and can be applied to industrial production of glycolide.

Description

technical field [0001] The invention relates to a production method of glycolic acid oligomer, which is prepared by polycondensing glycolic acid. Glycolic acid oligomers are important raw materials for the preparation of glycolide, and glycolide is the most commonly used monomer for the preparation of high molecular weight polyglycolic acid. [0002] Enhancing the conditions of the polycondensation reaction to make the polycondensation reaction fully; and then depolymerizing the obtained glycolic acid oligomer to prepare glycolide, and the content of impurities in the obtained glycolide is relatively low. The method ensures high-purity glycolide and provides convenience for the next step of refining and purification. Background technique [0003] Polyglycolic acid is an aliphatic polyester with excellent biodegradability and biocompatibility. It is widely used in internal fixation of human or animal fractures, repair of bone defects, repair of muscles, and human or animal b...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C59/06
Inventor 肖田鹏飞王睿周文乐朱煜
Owner CHINA PETROLEUM & CHEM CORP
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