| 摘要 |
PURPOSE:Crude glycollide is melted by heating and added dropwise to an organic solvent under stirring at a specific temperature, then the resultant glycollide suspension is cooled down to a specific temperature, the precipitate is separated and dried, thus obtaining high-purity glycollide in high yield. CONSTITUTION:Crude glycollide is melted by heating and added dropwise to an organic solvent preferably ethyl acetate, which is kept at 10 deg.C to its boiling point, preferably 15-20 deg.C, under stirring, to effect the extraction of impurities into the solvent and partial precipitation of the glycollide simultaneously. The resultant suspension is cooled down to 0-20 deg.C, preferably 5-10 deg.C for about 2hr to effect the precipitation of most of the glycollide. The resultant precipitate is separated and dried to give purified glycollide which is used as a starting substance of polyglycolic acid which is made into fibers for medical purposes such as suture. The process of the present invention causes no thermal deterioration according to long-hours of heating and yield reduction according to repetition of recrystallization and gives the objective glycollide with advantage.
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