Influence of Shungite from the Bakyrchik Deposit on the Properties of Rubber Composites Based on a Blend of Non-Polar Diene Rubbers

The study investigates the influence of a hybrid filler system based on carbon black, silica (SiO2) and shungite from the Bakyrchik deposit on the curing behavior of rubber compounds as well as on the physical–mechanical properties and thermal stability of vulcanizates based on a blend of butadiene-alpha-methylstyrene and isoprene rubbers. The morphology and elemental composition of shungite were examined using SEM-EDS analysis. Thermogravimetric analysis of shungite was also performed. The introduction of shungite led to a decrease in Mooney viscosity and an increase in scorch time. Rubber composites containing 10–20 phr (parts per hundred rubber) of shungite exhibited a satisfactory balance between the processing properties of the rubber compounds and the physical–mechanical properties of the vulcanizates (tensile strength, elongation at break, and rebound resiliency), which makes them promising for practical application. When 10 phr of shungite was added, the tensile strength of the rubber composites after thermal aging remained at the level of the control sample, while the changes in elongation at break, rebound resilience, and hardness were less pronounced than in the control.