Environment-Friendly, High-Performance Lignin-Derived and Polyvinyl Alcohol Blended Resin for All-Green Natural Fiber-Reinforced Composite

Abstract With the growing awareness of mitigating greenhouse gas emissions, developing bio-based, multi-functional, water-based and high-performance resins is in urgent demand for structural applications. This study demonstrates how water-based lignin-polyvinyl alcohol (PVA) resins can be used as a matrix in natural-fiber-reinforced composites for high-performance applications. The lignin-derived water-based resin is synthesized by blending demethylated lignin quinone (DLq) and PVA to obtain PVA-blended-DLq (PDLq) resin, followed by thermal curing. Compared to neat PVA, the optimized PDLq resin demonstrates a significant 30.5% increase in tensile strength to 162.86 MPa and a 45% improvement in Young’s modulus to 8.52 GPa. It also shows good UV shielding performance, around 100% for UVB and 99.5% for UVA. Compared to previously reported jute composites, the treated jute fiber (TJF)-reinforced PDLq composite fabricated through hot pressing demonstrates superior flexural strength, 190.9 ± 7.1 MPa and flexural modulus, ~ 13.8 GPa. The water-based PDLq resin synthesized shows potential for UV shielding and all-green natural-fiber-reinforced PDLq composite for indoor high-performance applications.