Method for preparing medical lactide

Abstract

The invention relates to a method for preparing medical lactide, comprising: adding a catalyst and a high boiling point solvent to lactic acid to carry out polycondensation reaction, so that the lactic acid generates oligomeric lactic acid; adding a catalyst to the generated oligomeric lactic acid to perform depolymerization reaction, Obtain medical lactide. In the method provided by the invention, a high-boiling solvent is added in the polycondensation process, so that the reaction system will not become viscous, difficult to evaporate, carbonized, and yellow due to the reduction of lactide distillation during depolymerization, ensuring the production process The stability and product quality, as well as the variability of physical indicators; and the yield is high, the reaction operation is simple, there is no danger, the production time is short, it is beneficial to industrial production, and it has high economic value.

Description

technical field [0001] The invention relates to the field of preparation of polymer compounds, in particular to a method for preparing medical lactide. Background technique [0002] Medical lactide is an important raw material for the synthesis of medical polylactic acid. As a new green material in the 21st century, medical polylactic acid material has broad prospects in biomedical materials. Polylactic acid is non-toxic, non-irritating, has excellent biocompatibility, bioabsorbability and biodegradability, and also has the advantages of high mechanical strength, stable chemical properties and easy processing. It can be used as a biomedical material for Drug sustained release carrier, surgical implant material. [0003] In the synthesis process of medical polylactic acid, the purity of lactide is very important. To make high molecular weight polylactic acid, high-purity lactide must be selected. The existing patents generally adopt the method of ring-opening polymerization...

AI Technical Summary

Problems solved by technology

[0015] 2. The reactants become viscous and carbonized as the distillation of lactide gradually decreases, making it difficult to distill and reduce the yield;

[0016] 3. The lactide distilled in the early stage and the lactide distilled in the later stage are unstable in terms of physical properties, and the variability is relatively large

[0023] 1. The reactant becomes viscous and carbonized as the distillation of lactide becomes less, resulting in difficulty in distillation and lower yield;

[0024] 2. There are dangers in the operation and recovery of heated high-temperature gas

[0031] 1. The color of lactide is yellow;

[0032] 2. The process is complicated, the production time is too long, and it is impossible to produce on a large scale