Siberian Federal University

Stabilizers are widely used in polymer products to preserve their performance characteristics by preventing degradation caused by environmental factors. The expanding applications of polymer materials drive the need for the development of effective stabilizers and the improvement of existing production technologies. A current trend in stabilizer chemistry is the synthesis of multifunctional antioxidants that operate through various mechanisms of polymer thermo-oxidative degradation inhibition. In this study, a multifunctional antioxidant – tris(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propyl)phosphite – was synthesized. The compound contains several ageing inhibition centers: a phosphorus(III) atom and sterically hindered phenolic groups. The target compound was obtained in high yield via the reaction of 2,6-di-tert-butyl-4-(3-hydroxypropyl) phenol with phosphorus trichloride in an inert atmosphere in the presence of triethylamine. The structure of the resulting product was confirmed by IR and ³¹P NMR spectroscopy. The antioxidant efficiency of the synthesized compound was evaluated based on its peroxide radical scavenging ability in a model reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Experimental results showed that the synthesized product reacts with DPPH at a higher rate constant (k = 3.786 ± 0,189 × 10⁻⁵ s⁻¹) than the industrial antioxidant Irganox 1010 (k = 3.029 ± 0,151 × 10⁻⁵ s⁻¹). The effectiveness of tris(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propyl)phosphite as a thermal antioxidant for polypropylene was also assessed. It was demonstrated that the synthesized compound exhibits a stabilizing effect comparable to that of the commercial synergistic antioxidant blend Irganox B 225 (a 1:1 mixture of Irganox 1010 and Irgafos 168)