Thermooxidation of lactam-based polyamides with amino end-groups. Thermooxidation of hexano-6-lactam and decomposition of 6-hydroperoxyhexano-6-lactam in the presence of primary amines

Oxygen consumption, reaction products and chemiluminescence in the course o f the thermooxidation of hexano-6-lactam melt in the presence of primary am ines as well as thermooxidation of lactam-based polyamides with amino end-g roups were studied. Amines induce the homolysis of amide hydroperoxides, pr imary products of the chain oxidation of lactams, and react with aldehydes originating from hydroperoxide homolysis. By condensation of amines with al dehydes, aldimines are produced together with singlet oxygen, the initiator of N-alkylamide oxidation. In polylactams prepared by hydrolytic polymeriz ation, the carboxylic and amino end-groups are associated and their effect on polymer thermooxidation is thus suppressed. (C) 1999 Elsevier Science Lt d. All rights reserved.