Molecular dynamics insights into temperature effects on polyurethane-aggregate adhesion: comparative analysis of SiO2 and CaCO3

In this study, molecular dynamics was used to investigate the adhesion properties between polyurethane and aggregate and to reveal the adhesion mechanism between polyurethane and aggregate. The influence of the aggregate type and temperature on the polyurethane-aggregate adhesion properties was investigated. The polyurethane-aggregate adhesion properties were evaluated using interaction energy, interaction energy fraction, adhesion work, radial distribution function, fractional free volume and relative concentration distribution. The adhesion properties between polyurethane-SiO 2 aggregate have temperature sensitivity, while temperature hardly affects the adhesion between polyurethane-CaCO 3 aggregate. Van der Waals forces and hydrogen bonding are the dominant factors affecting the adhesion properties of polyurethane-SiO 2 aggregates, while electrostatic energy is the main contributor to the adhesion properties of polyurethane-CaCO 3 aggregates. The temperature increased reduced the molecular gap between the polyurethane and SiO 2 and increased the interaction force between the polyurethane molecules and SiO 2 .