Fabrication and performance evaluation of aminopropyl triethoxysilane-dopamine-MoS₂ incorporated SBS modified asphalt

In this study, a green and simple method was developed to deposit aminopropyl triethoxysilane-Dopamine (APs-DA) hybrid coating on the surface of MoS₂ under mild reaction conditions using non-toxic reagents. The resulting composite (APs-DA-MoS₂) was in turn used as a modifier to conventional styrene–butadienestyrene (SBS) modified asphalt. The deposition of APs-DA over MoS₂ and spherical morphology of the composite was confirmed by Fourier transform infra-red (FT-IR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) showed higher thermal stability (increased initial decomposition temperature by 28 °C) of APs-DA-MoS₂ incorporated asphalt as compared to the pristine SBS modified asphalt. Fluorescence microscopy (FM) confirmed the development of a proper network structure in the APs-DA-MoS₂ modified asphalt which contributed towards its enhanced mechanical, viscoelastic and thermal stability properties, resistance against rutting and fatigue performance as confirmed by dynamic shear rheological (DSR), multi stress creep and recovery (MSCR), time sweep and rotational viscosity (RV) tests. The elastic modulus (G') (46 °C, 10 Hz) of SBS modified asphalt was increased by 51.09% upon the incorporation of 0.08% APs-DA-MoS₂. Attributed to the facile and environmentally benign synthesis approach, enhanced mechanical properties, thermal stability, resistance against rutting and fatigue performance, this study provides useful reference for the fabrication of APs-DA-MoS₂ modified asphalt for practical applications in highway and construction industry.