2,6-DI-TERT-BUTYL-4-(3-HYDROXYPROPYL)PHENOL: SYNTHESIS AND ANTIOXIDANT ACTIVITY

In polymer chemistry, stabilizers are used to maintain the physical-mechanical and optical properties of materials at levels necessary for their performance under prolonged environmental exposure. The growing market and the expanding range of polymer applications create a demand for the development of technologies and methods for the production of new types of antioxidants. A modern approach in antioxidant chemistry involves the design of multifunctional compounds capable of acting simultaneously as free radical scavengers and hydroperoxide decomposers. For many years, research has focused on the development of multifunctional antioxidants based on substituted phenols of various structures. To be used as intermediates in the synthesis of multifunctional compounds, such substituted phenols must contain additional reactive groups. This paper presents the results of the synthesis of 2,6-di-tert-butyl-4-(3-hydroxypropyl)phenol, which may serve as an intermediate for the preparation of multifunctional phosphorus-containing antioxidants. The compound was synthesized under both atmospheric and elevated pressure by the reaction of 2,6-di-tert-butylphenol with allyl alcohol in the presence of alkali. The structure of the obtained product was confirmed by ¹H NMR, ¹³C NMR, and FTIR spectroscopy. The efficiency of 2,6-di-tert-butyl-4-(3-hydroxypropyl)phenol as a radical scavenger was evaluated in a model reaction with 2,2-diphenyl-1-picrylhydrazyl (DPPH). It was experimentally determined that the reaction follows first-order kinetics with a rate constant of 3.672 × 10⁻⁵ s⁻¹, which is comparable to that of the commercial antioxidant Irganox 1010. The effect of 2,6-di-tert-butyl-4-(3-hydroxypropyl)phenol on the oxidative stability of industrial oil I-20A under thermal oxidation conditions was also investigated. According to GOST standards, thermal oxidation of the oil was carried out at 170°C for 4 hours, with an oxygen flow rate of 300 cm³/min. It was found that the addition of the synthesized compound led to a reduction in the amount of sediment formed during thermal oxidative degradation, at a level comparable to Irganox 1010. However, the amount of low molecular weight acids and the acid number were higher in the presence of 2,6-di-tert-butyl-4-(3-hydroxypropyl)phenol compared to the oil stabilized with Irganox 1010.