High‐Performance, Recyclable, and Degradable Bio‐Based Epoxy Resins Based on Dynamic Covalent Imine Bonds

ABSTRACT Epoxy resins are widely utilized in many fields due to their good mechanical properties, thermal properties, and chemical stability. However, most of the reported epoxy resins are characterized as nondegradable and nonrecyclable thermosetting materials, causing great environmental pollution and resource waste. Herein, we report a fully bio‐based and recoverable epoxy resin using a bio‐based epoxy monomer and curing agent. The epoxy monomer (VAN‐TA‐EP) was synthesized by a Schiff base reaction based on vanillin (VAN) and Tris(2‐aminoethyl)amine (TA) and further epoxidated. The bio‐based imine curing agent (DI) was synthesized from diformylfuran (DFF) and isophorone diamine (IPDA). The resultant epoxy resin TA/DI that composed of VAN‐TA‐EP and DI, showed high performance, degradability, and recyclability. The tensile strength of the prepared bio‐based epoxy resin reached a maximum of 104 MPa, which is significantly higher than that of the conventional DGEBA/DDM (59 MPa). The epoxy resin was demonstrated to be heated and reshaped by the imine metathesis, which was experimentally confirmed. Furthermore, the cross‐linked resins have good degradability to the acid‐ or base‐induced hydrolysis of imine bonds. This study paves the way for the preparation of high‐performance and recyclable bio‐based epoxy resins.