Development and Characterization of Hybrid Coconut-S-Glass Fiber Composites for Enhanced Mechanical and Thermal Performance

Composite materials are replacing traditional metals across various industries as they offer lighter weight and affordability, as well as excellent mechanical properties. In the present work, a hybrid composite was developed by combining randomly oriented S-glass fibers and coconut fibers within an epoxy matrix by using the hand lay-up method. The laminate was prepared by using two sheets of raw coconut fiber and eight layers of 200 GSM S-glass fiber, maintaining an epoxy-to-hardener ratio of 10:1. The laminate was cured under a hydraulic press at 80 °C for two hours and then post-cured at a temperature of 100 °C for four hours. In order to assess the performance of the composites, a series of tests, including mode II interlaminar fracture toughness, tensile strength, impact resistance, and hardness, as well as thermal conductivity, were performed. SEM analysis of the fracture surfaces confirmed the combined presence of fiber pull-out and good fiber–matrix bonding, supporting the observed improvements in mechanical properties. The results indicate that the hybrid composite has clear advantages over the composites reinforced with individual fibers alone. It showed a 358% higher tensile strength, a 30% increment in impact strength, and roughly 31% better flexural strength as compared to the coconut fiber composite. In comparison to the glass fiber composite, the hybrid composite offered enhanced toughness and better thermal stability, along with lower material costs and improved sustainability due to the addition of the natural fibers. Considering the rising need for lightweight, strong, and eco-friendly materials for industries, this fabricated hybrid composite appears to be a promising option for structural applications in fields like automotive, aerospace, and construction, where reducing weight without compromising strength is essential.