Photooxidation of polystyrene. Effect of stabilizers

Abstract

AbstractThe effect of commercially available stabilizers such as Tinuvin‐327, Tinuvin‐770, and Irganox‐1024 on the photooxidation of polystyrene (PS) was investigated by following the changes in molecular weight and molecular weight distribution. Structural changes during degradation were studied by 1H‐NMR‐ and IR‐Spectroscopy and by Electron Spectroscopy for Chemical Analysis (ESCA). Neat PS films became very brittle and yellow on exposure to UV light. Tinuvin‐770 stabilized the PS films towards discolouration and brittleness.The ESCA studies of surface photooxidation of polystyrene indicate the formation of ketonic and methylene ether groups in the initial stages (˜ 100 h). At later stages ester and carbonate groups are formed.