Optimization and multi-objective analysis of tensile, flexural and impact strength in nano-hybrid bio-composites reinforced with Helicteres isora, Holoptelea integrifolia fibers, and nanographene
Boopathy Krishnasamy, Priya Thirugapillai, Amuthakkannan Rajakannu, Mayakannan Selvaraju
Abstract
ABSTRACT Industries worldwide seek sustainable, high-strength bio-composites to reduce carbon footprint and replace synthetic materials. This research enhances natural fiber-based composites, ensuring lightweight, cost-effective, and eco-friendly alternatives. It supports green manufacturing and sustainable engineering, promoting a shift away from fossil-based materials. This study aims to optimize the mechanical properties of nano-hybrid bio-composites reinforced with Holoptelea integrifolia fibers, Helicteres isora fibers, and graphene nanosheets within a polypropylene matrix. Using the Box-Behnken design and Response Surface Methodology (RSM), the effects of fiber and graphene composition on tensile, flexural and impact strength were analyzed. The Multi-Objective Particle Swarm Optimization (MOPSO) approach was employed to maximize strength while minimizing composite weight. The optimized composition (15.6721 wt% Holoptelea integrifolia, 15.7198 wt% Helicteres isora, and 0.9307 wt% graphene) achieved a tensile strength of 45.407, flexural strength of 62.0344 MPa and impact strength of 147.119 J/m, demonstrating a significant enhancement. FESEM analysis revealed improved fiber-matrix adhesion, reduced voids, crack path deviation, and fiber bridging mechanisms, which enhanced fracture resistance. These findings support the development of lightweight, high-performance bio-composites, making them ideal for automotive, aerospace, and structural applications where improved strength-to-weight ratios are crucial.