Recent Advances in the Extraction of Lignin and Cellulose for Integration into Reprocessable Vitrimer-Based Composite Networks

The growing demand for sustainable alternatives to petrochemical-derived materials has established lignocellulosic biomass as a viable precursor for the synthesis of high-performance bio-based polymers.Among its primary elements, lignin and cellulose demonstrate advantageous structural and chemical properties that facilitate their integration into dynamic polymeric networks, such as vitrimers.This incorporation promotes the production of reprocessable carbon fiber-reinforced composites (CFRCs) with enhanced ecological profiles.Notwithstanding their potential, the effective utilization of lignin and cellulose is hindered by various technical difficulties, including variability in biomass composition, inconsistent extraction yields and purity levels, as well as the limited scalability of advanced processing methodologies.This review precisely evaluates cutting-edge extraction and processing techniques, with a specific focus on traditional methods in conjunction with novel green solvents such as organosolv systems, ionic liquids, and deep eutectic solvents.The discourse also investigates the functionalization approaches and catalytic systems essential for establishing dynamic covalent bonds within vitrimer matrices, in addition to fiber-matrix interfacial engineering crucial for optimizing CFRC performance.Central considerations regarding mechanical durability, environmental robustness, and recyclability are discussed, underscoring existing limitations and areas that necessitate further exploration.