Evolution of bamboo derivative fiber-mollusk shell based calcite particulate hybrid reinforced epoxy bio-composites for sustainable applications

This study focused on the development of environmentally friendly epoxy-based biocomposites by incorporating bamboo fiber (BF) and calcite particles (CP) as reinforcements. A total of 125 specimens were fabricated with different weight percentages of BF and CP ranging from 0% to 15% to the epoxy. The biobased reinforcements were processed before incorporation, and the hand layup technique was used to fabricate the composites, which were then cured at ambient temperature. Evaluations of selected properties were carried out to ascertain the most probable areas of application, while the fracture surfaces were examined using SEM. The results indicated that the inclusion of these hybrid bio-reinforcements significantly enhanced the properties of the biocomposites compared to unreinforced samples. The optimal composition was identified as 12 wt% BF/CP, which demonstrated the highest ultimate tensile strength (32.84 MPa) and tensile modulus (1.9 GPa), attributed to the strong interfacial bonding between the epoxy matrix and the BF/CP reinforcements. Additionally, the flexural strength (55.38 MPa) and modulus (2.72 GPa) were improved due to the effective load transfer and stiffening effect of the calcite particles. The hardness (67 HS) and wear index (0.015 mg) were enhanced by the toughening mechanism provided by the bamboo fibers, while the density (1.195 g/cm³) remained within a desirable range for lightweight applications. Composites with 9 wt% BF/CP exhibited the highest impact strength (22.66 J/m2), likely due to the optimal balance of fiber-matrix interaction and energy absorption capacity. These findings indicate that the developed hybrid-reinforced biocomposite compositions hold great promise with the improved physical and mechanical properties as seen and can be utilized for various applications, including automotive, aerospace, and other engineering applications.