Fabrication of an Environmentally Friendly Modifier Based on DAh-MT-MoS2 via Codeposition for the Preparation of Composite TB Rubberized Asphalt

Abstract

Adding rubber made from waste tires to asphalt can promote sustainable development of resources on roads. Molybdenum disulfide, as a nanoscale layered solid lubricant, can enhance the compatibility of rubber-modified asphalt, effectively addressing the issues of high viscosity and poor construction performance of asphalt at elevated temperatures. However, molybdenum disulfide tends to undergo self-agglomeration within the polymer matrix. To address this issue, the present study employed a polyphenol bionic coating method. Modification of molybdenum disulfide was achieved through the codeposition of hydrochloric acid dopamine (DAh) and (3-Mercaptopropyl)trimethoxysilane (MT), resulting in the formation of a bionic coating on its surface (DAh-MT-MoS2). Subsequently, it is blended into the rubber and basic asphalt, followed by further research into the performance of the composite modified asphalt. Microtests validated the superior effectiveness of the bionic coating method, effectively alleviating the self-agglomeration phenomenon of molybdenum disulfide. The research results indicate that the addition of DAh-MT-MoS2 not only improved the temperature sensitivity of asphalt at high temperatures but also reduced the high-temperature viscosity. Furthermore, DAh-MT-MoS2 enhanced the viscoelastic properties of rubber-modified asphalt and helped decrease its deformation sensitivity under varying stress levels, thereby improving its resistance to deformation. Notably, at 46°C, the storage modulus and loss modulus of 0.09% DAh-MT-MoS2/terminal blend (TB) rubberized asphalt (TBRA) increased by 115.0% and 138.9%, respectively, compared with TBRA. The results from the bending beam rheometer and storage stability demonstrate that the addition of DAh-MT-MoS2 effectively enhances the crack resistance of asphalt at low temperatures and improves the storage stability of the asphalt. The addition of an appropriate amount of DAh-MT-MoS2 facilitates sulfur cross-linking reactions within rubber and asphalt, forming a three-dimensional spatial structure where rubber and asphalt are either continuous or intertwined (as observed through fluorescence microscopy). This enhances the bonding between rubber particles and asphalt, ensuring a closer connection. Simultaneously, this significantly retards the thermal decomposition process of asphalt (validated through thermogravimetric analysis), thereby enhancing the heat-resistance performance of rubberized asphalt under high-temperature conditions in summer.