12-氨基十二酸精制工艺条件的研究

Study on the Technological Conditions of Refining 12-Aminododecanoic Acid

采用1,1'-过氧化双环已胺(PXA)法制备尼龙-12,需要对含有其单体-12-氨基十二酸(12-ADA)的11-氰基十一酸加氢产物予以精制。以12-ADA的产品纯度与收率为目标函数,用有机溶剂重结晶法进行精制,考察了结晶工艺条件对精制效果的影响。实验结果表明,优化工艺条件为:结晶介质为异丙醇-水-浓氨水(质量比3:3:1)的混合溶液、初次结晶温度为15℃、重结晶温度为40℃、重结晶母液重复利用1次,在此条件下,精制的12-ADA晶体纯度和收率分别可达99.6%和92.3%。

It is inevitable to separate 12-aminododecanoic acid （12-ADA）from the hydrogenation product of 11-cyanoundecanoic acid （11-CUA） during the process preparing nylon-12 by 1,1＇-peroxydicyclohexylamine （PXA） method. On the basis of taking purity and yield of 12-ADA crystals as objective functions, influences of the changes of technological conditions of recrystallizing the hydrogenation product of 11-CUA in organic solvent on refining effect were investigated here. Experiment results indicate that the optimization process conditions are that crystallization medium is the mixture of isopropanol with water and strong aqua （mass ratio of them is 3：3：1）, first crystallization and recrystallization temperature are 15℃～20℃ and 40℃ respectively, reuse times of the recrystallization mother liquor is less than two times. Under these conditions, product purity and yield of refining 12-ADA can reach 99.6% and 92.3% respectively.