Exploring the thermal and mechanical performance of hybrid bio composites reinforced with agro waste fibers and Turbinella pyrum shell powder

Abstract

The use of sustainable natural fiber-reinforced polymer composites has attracted considerable attention mainly because they are environmentally friendly and can replace heavy components in engineering. The present work involves making hybrid epoxy composites reinforced with banana stem fiber (BSF), sugarcane bagasse fiber (SCF), and Turbinella pyrum shell (TPS) powder by the vacuum-assisted resin infusion technique. Nine composite samples (S1-S9) were made by changing fiber and TPS filler amounts to study the mechanical, thermal, moisture resistance, and morphological properties of the composites. The study found that the addition of the TPS filler might be the biggest reason for the composite’s better performance, which increased with filler content up to a maximum of 3 wt%. S6 showed the best tensile strength (20.0 MPa), tensile modulus (2.95 GPa), flexural strength (49.8 MPa), flexural modulus (4.48 GPa), and impact strength (8.1 kJ/m 2 ); these properties were 332.9%, 136.0%, 255.7%, 250.0%, and approximately 523.1% better than the unfilled S1 formulation. S5, in contrast, has the highest compressive strength (9.40 MPa), compressive modulus (1.34 GPa), and minimum moisture absorption (1.95%), which indicates very good resistance to water. The composite formulation with the lowest weight and highest strength was selected, based on different performance criteria (mechanical, thermal, and moisture resistance), by multi-response optimization. It was revealed that S6 was the composite formulation showing the most balanced characteristics. Thermogravimetric studies showed that the composites with TPS filler have better thermal capability, and SEM imaging revealed discrepancies among composite samples for fibre pull-out, void presence, filler dispersion, and the nature of the crack. EDX analysis was used to detect the calcium carbonate (CaCO 3 ) enriched material of the TPS filler, and its contribution towards the increase of composites’ stiffness and thermal resistance was acknowledged. These results portray the possibility of using TPS-filled hybrid epoxy composites as green products for lightweight structural and engineering applications.