熔融分步结晶提纯L-丙交酯

Purification of L-lactide by melt fractional crystallization

以实验室制备的粗丙交酯为原料,采用熔融分步结晶法对提纯丙交酯进行了实验研究,考察了熔融分步结晶过程中结晶时间、结晶温差、发汗时间等参数对产品质量分数、结晶率、母液质量分数、组分收率以及提纯能力的影响,同时,对结晶和发汗过程的提纯能力进行了对比研究。结果表明:在给定的原料组成下,较适宜的结晶时间为60 min,结晶温差为20℃,发汗时间为50 min,发汗过程提纯能力是结晶过程的1.77倍。

With the crude lactide prepared in laboratory as feedstock,the process of melt fractional crystallization to purify the crude L-lactide was studied.The effects of operating parameters,such as crystallizing time,crystallizing temperature difference and sweating time on the product mass fraction,the crystallization rate,the mother liquid mass fraction,the product component yield and the purification capacity were investigated.The purification capacity of the process of crystallizing and sweating was comparatively studied.The experimental results show that the optimum crystallizing time is 60 min,crystallizing temperature difference is 20 ℃,and sweating time is 50 min.Under such conditions,the purification capacity of sweating is 1.77 times as much as that of crystallization.