2-乙基己酸亚锡催化合成丙交酯的合成工艺研究

丙交酯是以乳酸为原料制备高分子量聚乳酸的中间体。研究以2-乙基己酸亚锡为催化剂,以D,L-乳酸为原料,在催化剂存在下通过脱水环化合成D,L-丙交酯。研究了催化剂用量、脱水时间、解聚温度对丙交酯产率的影响。实验结果表明,采用2-乙基己酸亚锡为催化剂,最佳催化剂用量为1.3%,最佳脱水温度为140℃,最佳解聚时间为90 min。用乙醇作为重结晶溶剂,可获得总产率达25.3%的纯D,L-丙交酯。通过熔点、红外光谱(IR)对产品进行了表征。

Study on the synthesis of lactide using stannous bis(2-ethylhexanoate) as catalyst

In this paper,the catalyst of stannous bis(2-ethylhexanoate) was prepared from diethyl malonate and halogenated hydrocarbon.D,L-lactide was prepared from D,L-lactic acid with bis(2-ethylhexanoate) as catalyst.Effects of catalyst dosage,dehydration temperature as well as decomposing time on yield of lactide were studied.The results showed that the proper amount of catalyst used was 1.3%,proper dehydration temperature was 140 ℃,the proper decomposing time was 90 min.With ethanol as an solvent for recrystallization,the total yield of purified lactide reached 25.3%.Lactide was identified by melting point measurement and infrared spectrum.