Recovery of hexamethylenediamine (HMD) with low polarographically reducible impurities (PRI) from mixtures of HMD, aminocapronitirle and PRI

摘要

A method for separating a mixture of hexamethylenediamine, aminocapronitile and polarographically reducible impurities using fractional distillation in which the temperature in the rectifying zone of a distillation column varies sigmoidally along its length to force a major portion of the PRI to co-distill with the aminocapronitrile.