Synthesis method of polyglycolic acid

Abstract

This invention provides a method for synthesizing polyglycolic acid, comprising the following steps: First, glycolic acid is prepared by fermentation. Then, a first process and a second process are sequentially performed. The first process includes anion exchange and a third process, the third process including electrodialysis or cation exchange. The second process includes freeze-drying or vacuum distillation to increase the glycolic acid concentration. Next, the glycolic acid is pre-dehydrated to reduce its water content, and then subjected to a condensation polymerization reaction to obtain polyglycolic acid.

Claims

1. A method for synthesizing polyglycolic acid, comprising: Glycolic acid is produced by fermentation. The first process and the second process are carried out in sequence. The first process includes anion exchange process and a third process. The third process includes an electrodialysis process or a cation exchange process. The second process includes a freeze-drying process or a vacuum distillation process to increase the concentration of glycolic acid. Glycolic acid is pre-dehydrated to reduce its water content, and the temperature is raised to 70°C to 80°C to remove water. Then, a condensation polymerization reaction is carried out to obtain polyglycolic acid.

2. The method for synthesizing polyglycolic acid as claimed in claim 1, wherein the fermentation method includes using a modified strain to convert a carbon source into glycolic acid.

3. The method for synthesizing polyglycolic acid as claimed in claim 2, wherein the carbon source comprises ethylene glycol.

4. The method for synthesizing polyglycolic acid as claimed in claim 2, wherein the modified strain has the ability to produce alcohol dehydrogenase, aldehyde dehydrogenase and bacterial heme.

5. The method for synthesizing polyglycolic acid as claimed in claim 1, wherein the concentration of glycolic acid produced by the fermentation method is from 50 g / L to 300 g / L.

6. The method for synthesizing polyglycolic acid as claimed in claim 1, wherein the first process and the second process are performed sequentially to increase the glycolic acid concentration to 70 wt% to 99 wt%.

7. The method for synthesizing polyglycolic acid as described in claim 1, wherein the molecular weight (Mw) of the polyglycolic acid is from 20,000 to 100,000.