Thermal-oxidative breakdown of polyphenyl quinoxaline☆

A study was made of thermal-oxidative breakdown of polyphenyl quinoxalines (PPQ) of different structures in the temperature range of 300–500°. It was shown that the overall heat stability of PPQ in the presence of oxygen decreases because of the ready interaction of nitrogen of the quinoxaline ring with oxygen. It was established that the formation of nitric oxide or nitrogen dioxide the decomposition of which results in oxidation of aromatic groups of polymer macromolecules, is the first stage of decomposition of polymers in the presence of oxygen.