Chemiluminescence of polyamides - III. Luminescence accompanying thermooxidation of lactam-based polyamides stabilized by antioxidants

Chemiluminescence accompanying oxidation of lactam-based polyamides stabili zed with phenols and secondary aromatic amines as well as with a hindered n itroxy radical was measured. The yields of chemiluminescence per mol of oxy gen absorbed were found to be higher for oxidation of polyamide in the pres ence of antioxidants than in their absence depending on the content of amin o and carboxylic end-groups. Because antioxidants react with peroxy radical s by several consecutive inhibition reactions with different yields of chem iluminescence, the intensity of chemiluminiscence also depends on the rate of initiation of the oxidation. The relation between the intensity of chemi luminescence and the rate of oxygen consumption during oxidation of stabili zed polyamides differed profoundly for various polyamides depending on thei r end-group content, on the concentration of antioxidant and also on the co nditions of oxidation, especially on the rate of initiation determining the rate of antioxidant consumption. Redox inhibition reactions were found to be the predominant source of chemiluminescence accompanying the oxidation o f N-alkylamides in the presence of antioxidants. (C) 2001 Elsevier Science Ltd. All rights reserved.