Studies on photocatalytic degradation of potystyrene

This paper reports the photo degradation of polystyrene (PS) by using zinc oxide (ZnO) as photo catalyst. Virgin PS is not responsive to degradation by ultra violet (UV) light because of the presence of phenyl rings in its repeating units. ZnO acts as an UV absorber and helps in transferring the absorbed energy to various bonds of PS and causes degradation. The concentration of ZnO followed by the dispersion within the PS matrix has been found to be the key as the maximum weight loss of similar to 16% in 2 In has been obtained with 0 center dot 5 wt-% of ZnO. Below and above this concentration, the degradation is clearly low. Addition of a UV sensitive dye has further improved this degradation (up to 18%) owing to synergism with ZnO. The degradation of PS has been further highlighted from infrared spectroscopy, surface analysis, viscosity average molecular weight studies and mechanical properties analysis. A suitable mechanism supporting the UV degradation has also been proposed.