合成丙交酯工艺的改进

Improvement on Productive Process of Lactide

采用氧化锌(ZnO)、氯化亚锡(SnCl2)、硫酸亚锡(SnSO4)、辛酸亚锡〔Sn(Oct)2〕以及它们的混合物催化合成丙交酯。实验结果表明,催化剂的种类和用量对丙交酯的收率有显著的影响。以ZnO/Sn(Oct)2为催化剂,用量为反应物总质量的2 0%时催化效果较好,能使丙交酯的收率高达45 2%。同时在N2流速为2L/min、压力为400Pa下采用减压气流法用于丙交酯的蒸出,收率比传统的减压法增加了8 1%。此外,还设计了一个在合成中能够有效分离丙交酯和乳酸的接收器用于接收丙交酯。

Zinc oxide,stannous chloride,stannous sulfate,stannous octanoate and their mixture were used as catalyst for the synthesis of lactide.The results showed that variety and quantity of the catalyst had marked influence on the yield of lactide.Thus,with 2% (based on total mass of reactants) ZnO/Sn(Oct)_2,yield of lactide reached 45.2%.Meanwhile,distilling lactide under reduced pressure of 400 Pa in N_2 stream of 2 L/min,the yield was 8.1% higher than that by traditional vacuum distillation.In addition,a device,which could seperate lactide from lactic acid effectively,was used to receive the lactide in the productive process.