Abstract: Glycolide (GA) with high yield and purity was prepared via the method of solvent depolymerization with glycolic acid oligomer as raw material，polyethylene glycol (PEG) as solvent and zinc oxide as catalyst. The structure and properties of GA were analyzed by IR，1H NMR and DSC. The solvent method could reduce the degree of coking of the reaction system，and the yield of glycolide was improved. The optimal synthesis conditions were found through orthogonal test as follows：amount of glycolic acid oligomer was 100 g，amount of PEG1000 was 20 mL，amount of zinc oxide was 0.75 g，reaction temperature was 250 ℃，reaction time was 2 h，average yield was 87.4%.

Key words: glycolide, preparation, coking, optimization

摘要： 利用溶剂解聚的方法，以乙醇酸低聚物为原料，聚乙二醇（PEG）为解聚溶剂，氧化锌（ZnO）为催化剂，合成出了高收率、高纯度的乙交酯（GA），采用红外、核磁、DSC等方法表征了GA的结构和性质。结果表明，采用PEG1000为溶剂，可以增大反应体系的流动性，有效降低反应体系的结焦积炭程度，提高GA收率。通过正交实验对合成条件进行了优化，得到了最优的反应条件，即：乙醇酸低聚物的用量为100 g，PEG1000的用量为20 mL，催化剂ZnO的用量为0.75 g，反应温度为250 ℃，反应时间为2 h，平均收率可达到87.4%。

关键词: 乙交酯, 制备, 结焦, 优化