Lignin-based composites processing, properties, and their applications: A Review

Abstract

Lignin, the most significant aromatic renewable natural resource available globally, it can be used in a wide range of value-added applications as a sustainable and environmentally acceptable substitute feedstock for chemicals and polymers obtained from fossil fuels. The emergence of lignin-based composites for use in packaging materials, wastewater remediation, biomedical engineering, additive production, automotive constructions, and energy storage systems has been expedited by recent developments in lignin valorization. With an emphasis on lignin extraction techniques, processing methods, compatibilization tactics, surface changes, and structure-property connections, this review article provides current advancements in lignin-based composites. The performance and sustainability of composites are examined in connection to several manufacturing techniques, such as extrusion molding, compression molding, resin transfer molding, and 3D printing. According to recent research, the compatibility between lignin and polymer matrices is greatly improved by chemical modifications. This improves mechanical strength, thermal stability, UV resistance, flame retardancy, and interfacial adhesion. Despite these developments, commercialization is still severely hampered by problems with lignin heterogeneity, processing variability, and large-scale industrial standardization. Thus, scalable lignin modification approaches, improved additive manufacturing, integration of the circular economy, and the generation of high-performance multifunctional bio composites should be the focus of upcoming research. In conclusion, lignin-based composites provide a highly promising pathway to environmentally sustainable and high-value materials that can replace petroleum-derived goods in a variety of industrial sectors.