Effects of waste wood oil content on thermodynamic and structural properties of bio-asphalt and interactions between components: a molecular dynamic simulation study

This study fully intends to elucidate the mechanism of waste wood oil (WWO) modifier content on the microscopic action of bio-asphalt by utilising molecular dynamics simulations. Molecular models of virgin asphalt and its components, WWO modifier, and bio-asphalt with different WWO contents were created and verified by the fluctuation parameters, radial distribution function (RDF), and thermodynamics parameters. In addition, the influence of WWO content on thermodynamic and structural properties of bio-asphalt and interactions between components was quantitatively evaluated through Hansen solubility parameter, intermolecular interaction energy, mean square displacement, RDF, and fraction of free volume. The simulation findings show that the compatibility of bio-asphalt is associated with the composition of the asphalt molecule and the compatibility ranking is not affected by the WWO content. In addition, the WWO modifier is most compatible with the resin and least with the saturate. The interaction energy between virgin asphalt and WWO and the particle migration in the asphalt models increases with increasing WWO content. Furthermore, the introduction of WWO increases the first RDF peak intensity of each asphalt component. An increase in WWO content does not change its own chemical composition. Moreover, the free volume of the system decreased as the WWO was added.