Kinetic effects of photoexposed isotactic polypropylene in the presence ofsome hindered-amine light stabilisers

A chemiluminescence study on photo-irradiated isotactic polypropylene in th e presence of three new HALS compounds, mercapto-1,3,5-triazinic phenolic s tabiliser (antioxidant T) and Tinuvuin 770 as standard was carried out. The oxidation prevention was assessed by the calculation of the main kinetic p arameters of thermal degradation process (oxidation induction time and maxi mum oxidation rate). Supplementary stability tests were performed on i-PP c ontaining four stabiliser couples (triazine + HALS) and the cooperative fac tors resulting from the synergistic activities of oxidation prevention coup le were determined. A kinetic treatment of the chemiluminescence data obtai ned from thermal ageing of stabilised isotactic polypropylene is presented. (C) 2000 Elsevier Science Ltd. All rights reserved.