基于分子动力学的生物质油改性沥青相容性研究

To investigate the compatibility of bio-oil modified asphalt binder, the matrix asphalt binder, bio-oil modified asphalt binder and SBS modified asphalt binder were constructed based on molecular dynamics, through the perspectives including thermodynamic parameters, Flory-Huggins interaction parameters and molecular polarity, quantitative analysis of the compatibility of bio-oil modified asphalt binder and SBS modified asphalt binder was conducted. Two types of modified asphalt binder can be also observed with the aid of fluorescence microscopy to further validate and support the numerical simulation results. It was found that there was an obvious secondary state transition of vitrification for SBS modified asphalt binder at 158 K and 294 K, while there was once time for bio-oil modified asphalt binder at 262 K;the solubility parameter of bio-oil was clo-ser to that of matrix asphalt binder;the Flory-Huggins interaction parameters of SBS modified asphalt binder (0.689 1) was higher than that of bio-oil asphalt binder (0.612 0);the electric dipole moment of bio-oil was higher than SBS modifier, thus there was a strong attraction and asso-ciative force in the bio-oil-matrix asphalt binder system. Because of the linear structure existed in SBS modifier, it was difficult to interact with asphaltenes and other polycyclic aromatic hydrocarbons;the SBS modified asphalt binder showed massive fluorescent spots and significant phase separation, while the bio-oil modified asphalt binder showed fewer fluorescent spots and a homogeneous phase state. Comprehensive analysis shows that the compatibility between bio-oil and matrix asphalt binder is better than SBS modifier.