Surface modification of bagasse fibers based on polyphenol-induced self-supplied lignin for the creation of composite SBS-modified asphalt

Agroforestry solid waste bagasse fiber (BF) possesses sustainable, carbon-neutral characteristics when used as a reinforcement material for asphalt pavements. However, the incompatibility between BF and the asphalt matrix limits its wide application. This study proposes a strategy for cost-effective and environmentally friendly modification of fiber surfaces, aiming to transform a drawback into an advantage. That is, the lignin in BF, which affects the tensile strength of fibers, is dissolved by a deep eutectic solvent (DES) system, and then the lignin is reborn on the surface of the fibers with the assistance of tannic acid. Based on the hydrophobicity and free radical trapping properties of lignin, regenerated lignin is expected to act as a natural coupling agent between BF and styrene-butadiene-styrene (SBS) asphalt materials and as an anti-aging agent for asphalt. The experimental results showed that the modified BF realized the enhancement of asphalt interfacial compatibility and toughening of asphalt matrix. Specifically, the shear resistance, viscoelasticity and rutting resistance of the modified BF/SBSmodified asphalt were improved by 46.61%, 22.67% and 30.06%, respectively, and the UV aging susceptibility was decreased by 75.02% compared with that of the BF/SBS-modified asphalt. In conclusion, this work introduces a simple and practical strategy for enhancing the interaction between BF and asphalt, which is crucial for advancing biomass recycling and green transportation development.