Investigating energy absorption and crack propagation in natural rubber–epoxy composites: design, fabrication, and fracture analysis

Abstract This study investigates the mechanical properties and failure mechanisms of natural rubber epoxy composites, focusing on their structural integrity and performance under bending loads. The objective is to evaluate the influence of rubber particle distribution on toughness and fracture behavior to enhance composite reliability. To achieve this, three-point bending tests were conducted to determine the flexural strength and modulus, followed by optical and scanning electron microscopy (SEM) analyses to examine failure characteristics at the microstructural level. The results indicate that the primary failure mechanisms involve interfacial debonding and stress concentration, significantly influencing crack propagation. The composites demonstrated a flexural strength of 0.150 GPa and a flexural modulus of 4.32 GPa, highlighting their potential for impact-resistant applications. These findings provide valuable insights for optimizing rubber–epoxy composites, making them suitable for automotive, construction, and industrial applications where enhanced toughness and durability are required.