Synthesis and characterization of triethoxyvinylsilane surface modified layered double hydroxides and application in improving UV aging resistance of bitumen

Layered double hydroxides (LDH) surface modified by triethoxyvinylsilane (TEVS) was prepared and characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Ultraviolet and visible (UV–Vis) spectrophotometry . FTIR and XRD showed that TEVS has been successfully grafted onto the surface of LDH. Compared with LDH, the agglomeration between the TEVS surface modified LDH (TEVS-LDH) particles was obviously weakened according to SEM. UV–Vis reflectance and absorbance analyses indicated that TEVS-LDH possessed better UV reflectance and absorbance than that of LDH. Then the effects of TEVS-LDH and LDH on the physical and anti-aging properties of bitumen were thoroughly evaluated. The storage stability test showed that TEVS-LDH existed more stably than LDH in bitumen, which was due to the surface modification of LDH which improved the compatibility between LDH and bitumen. The results of physical properties tests showed that TEVS-LDH improved high-temperature behavior and had a less pronounced effect on the low temperature ductility of bitumen in contrast with LDH. Aging indices (viscosity aging index, softening point increment and ductility retention rate) and FTIR showed that TEVS-LDH exhibited better improvement than LDH on anti-ultraviolet aging of bitumen.