Study on Preparation and Antiaging Properties of Tinuvin P/OMMT-Modified Asphalt

ABSTRACT

Aging is an unavoidable environmental element that speeds up the degradation of asphalt pavement. In order to obtain sustainable asphalt pavement performance, a composite modified asphalt was prepared by using organically modified nanomontmorillonite (OMMT), which has outstanding thermal oxygen resistance, along with a light stabilizer (Tinuvin P) known for its effective ultraviolet (UV) light absorption properties. Nanomontmorillonite underwent an organic treatment to transform it from hydrophilic to hydrophobic, enhance its interlayer spacing, and enhance its dispersion potential in asphalt. The response surface methodology was employed to optimize the preparation process by considering the content of OMMT and Tinuvin P, as well as shear temperature as key variables. The evaluation criteria included the penetration and softening point of the asphalt. The findings indicated that the modified asphalt exhibited optimal performance when Tinuvin P was at 5.5 wt% and OMMT at 3.5 wt%, with a shear temperature of 136°C, a shear time of 30 min, and a shear rate of 3,000 RPM. The asphalt samples were aged by sequential thin film oven test and UV aging. Tests involving physical properties, UV spectrum analysis, and Fourier transform infrared spectroscopy tests revealed that the lamellar structure of OMMT inhibited the diffusion of heat and oxygen into the asphalt and slowed down the reaction between asphalt and oxygen. Tinuvin P effectively absorbed a significant portion of UV light within the 280–400 nm range. The combined effect of both components improved the aging resistance of modified asphalt.