Study on the properties of polydopamine/hexadecyltrimethoxysilane co-deposition functionalized modified graphene oxide and composite styrene-butadiene-styrene modified asphalt binder

A composite graphene oxide (GO) modifier was prepared by co-deposition of polydopamine (PDA) and hexadecyltrimethoxysilane (HDTMS) with hydrophobic function to enhance the interfacial interaction between GO and asphalt. Dopamine as a medium enhances the adhesion of the hydrophobic functional material HDTMS on the surface of GO. And the long alkyl chains of HDTMS molecules greatly reduce the surface free energy and ensure the dispersion stability of composite GO modifier in styrene-butadiene-styrene (SBS) modified asphalt. The physical properties of modified asphalt show that the ductility, high-temperature stability, and viscosity of asphalt can be improved by the addition of PDA/HDTMS composite GO modifiers (DH-GO). Among them, 0.04% DH-GO composite SBS modified asphalt binder (DH-GO/SBSMB) has the best mechanical properties. Compared with 0.05% GO composite SBS modified asphalt binder (GO/SBSMB), the softening point of 0.04% DH-GO/SBSMB increased by 8.3%, the penetration degree decreased by 9.7%, and the elongation increased by 18.2%. Dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR) and rotational viscosity (RV) tests show that 0.04% DH-GO/SBSMB has higher high-temperature stability, plasticity, and viscosity than 0.05%GO/SBSMB, which meets the requirements of asphalt construction specifications.