Participation of the charge-transfer complexes in the radiation-induced chain oxidation of aromatic amines in polymer films

The chain redox reaction in γ-irradiated solid films of poly(vinyl chloride) (PVC), containing N,N,N',N'-tetramethyl-4,4'-diaminodifenylmethane (Am) and CBr4, was studied. The formation of charge-transfer complexes between Am and CBr4 and also between Am · radicals and CBr4, the participation of these complexes in the chain oxidation of Am were investigated by ESR, spectrophotometry and luminescence methods. The spectral-luminescent properties of Am · radicals both isolated and interacting with the PVC matrix were discussed. It was discovered the quenching of luminescence of Am · radicals by molecules of CBr4. The effects of annealing temperature and concentration of CBr4 on the quenching of luminescence of Am · radicals were observed. Stern-Folmer's equation was used for the description of the static quenching of Am · radical fluorescence. It was shown that this quenching could be due to the formation of ground-state charge-transfer complexes between Am · radicals and CBr4. The kinetic features and mechanism of the radiation-induced chain oxidation of Am with the participation of the charge-transfer complexes were investigated