Mechanical and thermal characterization of coir/hemp/polyester hybrid composite for lightweight applications

Individual applications of coir and hemp as reinforcement in composites have been exhaustively studied; however, their hybridization must also be investigated. In this context, this research investigates the utilization of coir and hemp fibers as reinforcements in a polyester-based hybrid composite system. The primary objective is to find out how these reinforcements affect the hybrid composites' mechanical (tensile, flexural, and impact) and thermo-gravimetric properties. To accomplish this, composite samples with varying weight proportions of coir and hemp fibers were fabricated, and extensive mechanical testing was performed. The findings from the tensile, flexural, and impact tests revealed an enhancement in the mechanical characteristics of the fabricated composites as the proportion of coir fiber grew and the proportion of hemp fiber reduced. The hybrid composite, containing 15% coir and 5% hemp fibers, had superior mechanical properties to the binary composite system. In addition, thermogravimetric analysis was performed to determine the thermal stability of the hybrid composites. Within a temperature range of 30 °C–800 °C, weight loss was observed, confirming the overall thermal resistance of the materials. Fourier Transform InfraRed Spectroscopy (FTIR) was used to determine the composite's chemical composition, revealing the presence of functional groups that contribute to the composite's performance. Utilizing Scanning Electron Microscopy (SEM), the surface morphology of hybrid composites was investigated, yielding valuable insights into the fiber-matrix interaction and composite structure. The results of this study demonstrate the potential of the coir/hemp/polyester hybrid composite as a lightweight material in a variety of industries.