Lignin structure defines the properties of asphalt binder as a modifier

This study aims to further illustrate the relationship between technical lignin structure and asphalt binder performance. Two types of technical lignins (soda lignin and kraft lignins), were prepared and fully characterized. Rheological performance tests were performed to study their effects on the asphalt binder performance. Soda lignin was dominated by linear beta-O-4' aryl ethers and possessed more multiple intermolecular H-bonds, which effectively enhanced the low-temperature performance by weakening the cross-linking between asphaltenes and lignins. Kraft lignin, which exhibited condensed C-C linkages and stronger dimeric intermolecular H bonds, performed as an effective asphalt binder modifier to improve the high-temperature rutting resistance.