Plasticizing Additive to Road Bitumens Based on High-Sulfur Brown Coal

Using the oxidation desulfurization method, a plasticizing additive for road bitumen was obtained from high-sulfur brown coal. Taking into account the need to maximize the quantity of the plasticizing additive while maintaining quality, constant conditions of the oxidative desulfurization process were selected and the influence of the main variable technological factors on it was investigated. The sample of a plasticizing additive was obtained in near-optimal conditions of the lignite oxidation desulphurization process. It was established that its addition to bitumen modified with coumarone-indene resin improves the plastic properties of the binder, while the softening temperature practically does not decrease. An increase in the plasticizer dosage increases both penetration and ductility of the resulting mixture. In terms of increasing ductility and penetration, the effectiveness of the plasticizing additive under study is somewhat lower than that of other industrial plasticizers used (e.g., residual extract of selective treatment), and vice versa in terms of reducing the softening point. We found that the resulting plasticizing additive, in contrast to the residual extract of oil fractions selective treatment, slightly improves the adhesive properties of bitumen modified with coumarone-indene resin.