Comparative characteristics of sterically hindered phenols and nitroxide radicals as stabilizers of polyethylene photodegradation

Introduction. Polymeric materials (PM) are increasingly used in various industries and agriculture. Under the action of UV light, PM are destroyed. UV stabilizers are used to protect PM from photodegradation. Their action is based on the absorption of the photoactive sunlight component or on the deactivation of excited molecules that have already absorbed a light quantum, as well as on the inhibition of dark light-induced reactions. The work objective is to provide a comparative analysis of compounds of the sterically hindered phenols (SHP) series and nitroxide radicals (NR) as the PM photodegradation inhibitors.Materials and Methods. Reagents of the “purum” grade, LDPE premium grade 15803-020 polyethylene film were used for the investigations. The stabilizer was applied to the film by dipping. Carbonyl groups in polyethylene were determined by IR spectroscopy. IR spectra were recorded on Varian-640 instrument.Research Results. 2,4,6-tri-tert-amylphenol (1), 2-methyl-4,6-di-tert-butylphenol (2), 4-acetylamino-2,2,6,6-tetramethylpiperidin-1-oxyl (3), 3-carboxamido-2,2,5,5-tetramethylpyrrolin-1-oxyl (4) were tested as stabilizers for photo-oxidative degradation of polyethylene...