Research Progress on Lignin‐Based Epoxy Resins: A Green and Sustainable Path From Biomass to New Materials

ABSTRACT The synthesis of epoxy resins from petroleum‐based raw materials is constrained by resource shortages and environmental pollution, highlighting the growing importance of using renewable biomass materials to produce environmentally friendly epoxy resins. As the second most abundant renewable resource in nature after cellulose, lignin offers advantages such as biodegradability, making it an ideal alternative to petroleum. However, its inherent structural heterogeneity and steric hindrance effects complicate the synthesis of epoxy resins. Chemical modification can effectively overcome this bottleneck and enhance resin performance. This paper systematically reviews the latest research progress on lignin‐based epoxy resins. First, the structural characteristics of lignin are analyzed. Subsequently, the regulatory effects of modification methods such as phenylation and hydroxymethylation on the performance of epoxy resins prepared from lignin are discussed in detail. Additionally, the application potential of lignin epoxy resins in coatings, adhesives, and carbon fiber fields is thoroughly analyzed. Finally, the challenges in its preparation process and performance optimization are analyzed, and future development directions are prospected.