Development and optimisation of carbon enriched natural fibre hybrid composites and their characterisation for sustainable applications

Growing environmental concerns and the increasing demand for sustainable materials have accelerated the development of bio-based hybrid composites as alternatives to conventional synthetic composites. In this study, fully bio-based hybrid composites reinforced with sugarcane bagasse fibres and bamboo charcoal were fabricated using polylactic acid (PLA) matrix by varying the proportions of the reinforcements to identify the optimum composition. Scanning Electron Micrographs revealed the influence of reinforcement composition on fibre–matrix interfacial bonding and fracture morphology while Fourier Transform Infrared analysis confirmed the presence of characteristic functional groups associated with cellulose, hemicellulose and lignin. Thermogravimetric and derivative thermogravimetric analysis revealed enhanced thermal stability with primary degradation occurring between 250 and 450°C and maximum degradation temperature was recorded at 315°C. Among the investigated formulations, the B/BC (30/70) composite exhibited the best overall mechanical performance, achieving a tensile strength of 10.21 MPa, flexural strength of 79 MPa and an impact strength of 0.73 J/m ² , owing to the synergistic interaction between sugarcane bagasse fibres and bamboo charcoal. In addition, the composites exhibited controlled moisture absorption behaviour that followed classical Fickian diffusion kinetics, indicating diffusion-controlled water transport. The combination of enhanced mechanical properties, good thermal stability, controlled moisture absorption and the utilisation of renewable agricultural waste materials demonstrated the potential of the developed hybrid composites as lightweight, biodegradable materials for non-structural applications such as packaging, horticultural products, decorative panels and low-stress consumer products with additional potential for adsorption-oriented applications.