The construction and application of asphalt molecular model based on the quantum chemistry calculation

To further develop the microscopic structure of asphalt, the new asphalt molecular model including 50 types of molecules was proposed. The dipole moment, molecular electrostatic potential, and HOMO-LUMO gap were calculated by quantum chemistry methods. Based on the polarity represented by dipole moment and molar mass, the molecules were further divided into the aromatics and resins molecules in theory. The result shows that the donor atoms are located in the benzene concentrated region are easily attacked by electrophiles. The accept atoms are located in saturated branched chains and cycloalkanes are easily attacked by nucleophiles. The HOMOLUMO gap shows that the asphaltene molecular meets with the experiment results of the asphaltene optical gap. The resins and aromatics molecular own similar chemical stability, both of them are more stable than asphaltene. Finally, 1H-NMR, elements analysis, and SARA components experiments were connected with the molecular model we presented to solve the molecular ratio of fourteen kinds of asphalt.