Comparative studies of dielectric conductivity of polymer-bitumen compositions of composites obtained on the basis of Baku oil bitumen 50/70 (BND 50/70) modified with ethylene-propylene ternary copolymer (SKEPT-60) and synthetic butadiene nitrile rubber (SKN-26) were conducted. A significant effect of the nature of the elastomer on the structure of polymer-bitumen compositions was determined. The nature of the change in the dielectric constant of bituminous compositions in a wide temperature range made it possible to reveal their structural features and to determine the presence of phase transitions, and their temperature. Polymer-bitumen compositions containing SKN-26 elastomer are characterized by a "gel" structure, and SKEPT-60 by a "sol-gel" structure. The changes in the structure of bitumen containing SKEPT-60 can be caused by the more complete melting of this elastomer than SKN-26, the formation of a coagulation polymer network and the increase of the resin fraction compared to asphaltenes. In this thesis, embrittlement temperature data were also studied: embrittlement temperature is slightly higher (within 0.1–0.2⁰C) than SKN (about 0⁰C) for SKEPT-containing polymer-bitumen compositions, which indicates that in a stable highly dispersed colloidal solution of SKEPT-containing bitumen, the particle size of the dispersed polymer phase is closer to that of the sol. The transition temperature of the bitumen structure from the colloidal solution to the true solution was determined: 112⁰С for SKEPT-60, and 102⁰С for SKN-26.

doi.org/10.32737/0005-2531-2024-44-51