氧化锌-辛酸亚锡催化制备丙交酯的工艺研究

L-乳酸为原料,氧化锌和辛酸亚锡为催化剂,采用高真空蒸馏方法制备丙交酯.研究了一定真空度下,脱自由水温度和时间的关系,脱结合水温度和时间对丙交酯产率的影响.结果表明:真空度0.095 MPa,脱自由水95℃,脱结合水的温度120～125℃时,丙交酯蒸馏温度最低为170℃,最高为205℃,所得丙交酯粗产率在86%左右.经过反复试验认为,真空度0.095 MPa,水浴95～100℃脱自由水,操作简单,可保证乳酸不被蒸出.

The Reseach on the Process of the Synthesis of Lactide

With L-lactic acid as raw material and ZnO-Sn（Oct）2 as catalyst,the lactide was synthesized by the oligomerization and depolymerization under high vacuum.The results show that with the 0.095 MPa vacuum,the dehydration temperature was 95 ℃,the polymerization temperature was 120～125 ℃,The lowest temperature oflactide distil lation was 170 ℃ and the highest temperature was 205 ℃,The crude production rate of lactide stabilized at around 86 %.