ABSTRACT
Lactams produced on an industrial scale usually contain insignificant quantities of starting raw materials and production intermediates, along with traces of the original impurities from compounds entering the production, and of products of their chemical transformation. The origin of amide admixtures should be sought in impurities present in cyclohexane or cyclohexanone, and in methyl derivatives of cyclopentane and cyclohexane, or of cyclopentanone and cyclohexanone. Cyclohexanone oxime appears in caprolactam as a production intermediate. Linear amines are formed from the respective linear alcohols, impurities which are present in cyclohexa-none, during oximation. The term “content of oxidizable compounds” in the case of caprolactam means the content of compounds which are oxidized by permanganate several orders of magnitude more quickly than caprolactam alone. Lactams were separated from other low molecular weight substances in the extracts by simple chromatographic methods. Potentiometrie titrations of carboxylic groups in polyamides are generally carried out using a combination of the glass and calomel electrode.
