Adhesion Improvement of Bio‐Based Epoxy in Environmentally Friendly and High‐Performance Natural Fiber‐Reinforced Composites

Abstract

AbstractDeveloping robust bio‐based epoxy against petroleum‐derived epoxy is necessary for environmentally friendly and high‐performance natural fiber‐reinforced composites. A bio‐based vanillin epoxy (VE) is synthesized from the lignin‐derived vanillin, and a thermoset resin is prepared after mixing it with a 4,4′‐diaminodiphenyl methane (DDM) hardener. Further, it is infused in high‐cellulose‐containing alkali‐treated jute fiber (TJF) mats through a simple approach to enhance the adhesion between the VE‐DDM and TJF. Bio‐based VE‐DDM resin shows better compatibility with TJF than petroleum‐derived bisphenol A diglycidyl ether (DGEBA) epoxy. The bio‐based VE‐DDM/TJF composite demonstrates the Tgis ≈165 °C, tensile strength is ≈83.12 ± 3.80 MPa, and Young's modulus is ≈2.86 ± 0.10 GPa with excellent flexural strength (138.72 ± 3.81 MPa) and flexural modulus (8.01 ± 0.11 GPa). It also shows merits regarding hydrophobicity, reduced water absorption ability, durability, and chemical resistance in an acidic medium. The natural fiber‐reinforced VE composites pave the way to produce environmentally friendly and high‐performance composites for structural applications.