Study on the Effect of Surface Modification on the Mechanical and Thermal Behaviour of Flax, Sisal and Glass Fiber-Reinforced Epoxy Hybrid Composites

Natural fiber-reinforced hybrid composites can be a better replacement for plastic composites since these plastic composites pose a serious threat to the environment. The aim of this study is to analyze the effect of surface modification of the natural fibers on the mechanical, thermal, hygrothermal, and water absorption behaviors of flax, sisal, and glass fiber-reinforced epoxy hybrid composites. The mechanical properties of alkaline treated sisal and flax fibers were found to increase considerably. Tensile, flexural and impact strength of glass/flax-fiber-reinforced hybrid samples improved by 58%, 36%, and 51%, respectively, after surface alkaline treatment. In addition, the hygrothermal analysis and water absorption capacity are studied and also the Interfacial bonding properties were analyzed using Scanning Electron Microscopic images. The thermal analysis using thermogravimetric analyzer reveals that the decomposition temperature for hybrid fiber reinforced composites are between 306 and 312 degrees C. In conclusion, surface treatment improves the performance of natural fiber in hybrid fiber-reinforced composites, particularly flax fiber.