Bio‐Based Epoxy Vitrimer Asphalt Incorporating Dynamic Imine Bonds for Enhanced Self‐Healing Performance

ABSTRACT Thermosetting epoxy asphalt possesses outstanding mechanical strength, fatigue resistance, and durability, making it a preferred material for demanding pavement applications. However, its permanent cross‐linked structure limits crack self‐healing and recyclability, raising sustainability concerns. In this study, a novel bio‐based epoxy vitrimer asphalt was developed by curing epoxy soybean oil (ESO) and commercial epoxy resin (E51) with a synthesized imine‐containing amine curing agent (TPA/D400). The incorporation of ESO not only enhances the renewable content but also contributes to a dynamic covalent network based on reversible imine bonds. Among the prepared samples with vitrimer contents ranging from 30 to 70 wt%, the composite with 50 wt% vitrimer (EEA50) demonstrated optimal comprehensive performance, exhibiting a tensile strength of 1.28 MPa and an elongation at break of 106.46%, which meets the specification requirements for heavy‐duty pavement. Fluorescence microscopy revealed a homogeneous phase morphology in EEA50, indicating good compatibility. Remarkably, scratch tests at 180°C showed that EEA50 could achieve significant crack closure within 120 min, attributed to the exchange reactions of dynamic imine bonds within the vitrimer network. This work presents a sustainable epoxy asphalt alternative, combining bio‐based resources with vitrimer chemistry to address the limitations of conventional thermosetting epoxy asphalt in pavement engineering.