Natural Fiber Composite with α-Resorcylic Acid Based Bio-Epoxy Matrix

Abstract

Comprised of biopolymer matrix and/or bio-fiber reinforcement, bio-composites are environmentally friendly, lightweight, sustainable, and normally biodegradable. Their unique characteristics have enabled them an alternative material for replacing conventional metallic materials and other composites such as glass fiber reinforced composites. This work is focused on developing and characterizing a novel bio-composite that combines a natural fiber reinforcement with a unique α-resorcylic acid-based epoxy bio-resin. Kenaf fiber mats are impregnated with the epoxy bio-resin and compression molded into a bio-composite. Thermal properties of the bio-composite are characterized with differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). Indentation testing in a micro-scale is conducted on the bio-resin matrix and the fiber cross sections. The elastic modulus of the fiber transverse cross section is found to be 7.8 GPa, higher than that of the bio-epoxy resin, 4.3 GPa. Furthermore, the tension performance of the bio-composite is evaluated and compared with that of a conventional epoxy composite with similar kenaf fiber percentage. The bio-epoxy composite has comparable tensile modulus and strength with the conventional epoxy composite. Finally, the fracture surface of the tested samples is characterized using scanning electron microscopy (SEM) and different failure modes, such as fiber fracture, fiber pullout, fiber defibrillation, and matrix fracture, are observed. It is concluded that this novel bio-composite has a great potential to replace conventional epoxy resin based composite for semi-structural applications.