Surface oxidation and degradation of polyethylene in a mixed argon-oxygen plasma

Changes in surface chemical composition and the rates of formation of gaseous degradation products under the action of a mixed argon-oxygen plasma on polyethylene (PE) were studied using multiple attentuated total internal reflection (MATIR) IR spectroscopy and mass spectrometry. It was found that the dilution of a gas mixture with argon decreased the rate of degradation of the material at argon contents higher than 30%. It was demonstrated that absorbance at the absorption bands of the main oxygen-containing groups in a PE film remained unchanged over an argon concentration range from 0 to 90%. Conceivable mechanisms of processes occurring in gas and solid phases, which allowed us to describe the phenomena observed, are discussed.