Aging Properties of Ultraviolet Absorber Intercalated Organo-Montmorillonite–Modified Bitumen Based on Rheological and Chemical Analysis

In order to improve the thermo-oxidative and ultraviolet (UV) aging resistance of bitumen, ultraviolet absorber (UVA) was intercalated into organo-montmorillonite (OMMT) and ultraviolet absorber-intercalated organo-montmorillonite (UVA/OMMT) was used to modify bitumen. Four kinds of UVA/OMMT, including UV326/OMMT, UV328/OMMT, UV531/OMMT, and UV770/OMMT, were prepared by organic intercalation of OMMT with different UVAs (UV326, UV328, UV531, and UV770). X-ray diffraction testing was used to evaluate the intercalation effect of UVA/OMMT. UVA/OMMT-modified bitumen was prepared by melt blending of the base bitumen with different UVA/OMMTs. Then, thin film oven testing and ultraviolet aging testing were carried out on the UVA/OMMT-modified bitumen. The effects of UVA/OMMT on rheological properties, generic fractions, and functional groups of bitumen before and after thermo-oxidative and ultraviolet aging were studied by dynamic shear rheometer testing, thin-layer chromatography with flame ionization detection, and Fourier transform infrared spectroscopy, respectively. Based on these, the thermo-oxidative and UV aging resistance of different UVA/OMMT-modified bitumens were evaluated based on the rheological and chemical indexes. Results show that UV326/OMMT and UV328/OMMT have better effects on the thermo-oxidative aging and UV aging resistance of bitumen than OMMT, while the UV531/OMMT and UV770/OMMT exhibit worse effects on the thermo-oxidative aging and UV aging resistance of bitumen than OMMT, which is related to the better intercalation effects of UV326/OMMT and UV328/OMMT, and the poor intercalation effects of UV531/OMMT and UV770/OMMT.