Green Epoxy Resin System Based on Lignin and Tung Oil and Its Application in Epoxy Asphalt

In this work, lignin-based epoxy was synthesized by reacting epichlorohydrin (ECH) and partially depolymerized lignin (PDL) and then used for modification of asphalt. The Diels-Alder adduct of methyl esters of eleostearic acid and maleic anhydride (ME-MA) was synthesized and used as a biobased curing agent. The structure of PDL-epoxy was characterized by FTIR and P-31 NMR. Nonisothermal curing kinetics and thermal properties of the cured epoxy resins were studied by differential scanning analysis, dynamic mechanical analysis, and thermogravimetric analysis, respectively. Curing behaviors of PDL-epoxy and a commercial epoxy DER332 were compared. Effects of epoxy content on rheological properties of the modified asphalt binder were studied using a parallel plate rheometer. Results show that the elastic behavior of asphalt binder at elevated temperatures was improved with increase in epoxy content.