One of the serious problems in polybutadiene rubber (PBR) production units is the color change in products, which is due to aging and the inability of antioxidants to protect the product, especially at high temperatures. In this study, the effects of amine-type antioxidant [octylated diphenylamine (OD)] and non-amine-type antioxidant (Irganox 1520) on the color yellowness, gel content and thermal stability of PBR, at concentrations of 500, 1000, 1500, 2500 and 4000 ppm, at temperature of 110 °C, and different aging times (1–10 h) were investigated. The results showed that the polymer with Irganox 1520 antioxidant has a higher thermal stability, less gel formation and lower color than polymer containing OD antioxidant; therefore, the Irganox 1520 antioxidant was more suitable.
