Incorporation of nanoalumina into a polymeric asphalt matrix: Reinforcement of the nanostructure, improvement of phase stability, and amplification of rheological parameters

This research aimed to reinforce the nanostructure of an asphalt matrix modified by SBS polymer (Poliflex 60/ 85-E) from the incorporation of aluminum oxide (Al2O3) nanoparticles, promoting improvement of phase stability and, consequently, amplifying rheological parameters at elevated temperatures. For this, the reference matrix was nanomodified with 0.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, and 12% of nano-Al2O3, by weight of asphalt binder. The experimental investigation analyzed the phase separation of nanocomposites and verified the rheological parameters at high temperatures, which directly impact storage stability, apparent viscosity, resistance to thermal and oxidative aging, and susceptibility to permanent deformations. As a result, it was observed that the presence of the nanomodifier improved the stability of phases from the nanostructural reinforcement of the matrix, which improved the polymer-binder interface and may have restricted the segregation action. Furthermore, improvement of rheological parameters at high temperatures was observed, indicating increase in thermal and oxidative aging resistance and decrease in susceptibility to permanent deformations. These improvements may be associated with the nanoscale properties of Al2O3, which reduced nanoporosity, linked to the infiltration and diffusion of oxygen inside nanocomposites, preventing the polymer's agglomeration action and increasing the recoverable portion of the investigated matrix.