Essentially the same products are obtained from the thermal decomposition of certain caprolactam oxidation products. It has been shown [370] that at relatively mild temperatures between 70 and 100 C, exposure of caprolactam to air results in the formation of hydroperoxy-e-caprolactam, which converts easily to adipic acid monoamide. Since caprolactam is always present during polymerization and in the resulting equilibrium polymer, these reactions and the effect of their extent on the molecular weight and the type and concentration of end groups of the corresponding nylon-6 polyamide have been studied in some detail, C371]. It was found that the decomposition of the caprolactam hydroperoxide was catalyzed by the adipic acid monoamide and that the latter acts as a chain terminator during the polymerization process. The corresponding polymer exhibited characteristics resembling that of polymers obtained by polymerizing caprolactam in the presence of carboxylic acids. As the extent of peroxidation increases, the molecular weight of the corresponding polyamide