High-sulfur shale oil as a component of rubber stocks

A plasticizer obtained from high-sulfur shale oil (S content 6.5%) was investigated as an additive for rubber compounds in quantities of 15 and 30% on medium-high acrylonitrile butadiene rubber, in comparison with dioctyl phtalate (DOP). The chemical composition of the shale ail additive was studied by chemical and spectral methods. The shale oil additive consisted mainly of compounds C-14-C-20. About 40% of the total product consisted of sulfur compounds, mainly heavy derivatives of thiophene. The shale oil additive contained 45% polar aromatic and hetero-element components. As opposed to DOP, the shale oil plasticizer does not contain ester groups. However, high content of sulfur compounds and polar components result in chemical interaction and a satisfactory compatibility of the additive with rubber. Rubber compounds containing shale oil had a lower hardness, tensile strength and tear resistance, as compared to compounds containing DOP, Regarding flexibility, resistance to low temperature, swelling in oil, fuel and wafer, both rubber compounds had similar properties at 15% plasticizers. The properties of rubber compound containing 15% shale oil are promising.