Development of sustainable silane-treated hemp fiber and Lansium parasiticum shell bio-filler-reinforced polyester composite

Natural fibre composites are globally recognized for their sustainability and functionality, yet challenges such as poor interfacial bonding and high moisture absorption limit their performance. This study developed and characterized a polyester-based hybrid composite reinforced with silane-treated hemp fibres and Lansium parasiticum shell powder—an underutilized agricultural byproduct. The effects of reinforcement loading on mechanical, wear, dynamic mechanical, hydrophobic, and flammability behaviours were systematically investigated. The 3 vol% filler (T3) formulation exhibited maximum tensile and flexural strength, while 5 vol% enhanced hardness and wear resistance. Excess filler loading led to agglomeration and property deterioration. Silane treatment significantly improved fibre–matrix adhesion, thermal stability, and water repellence, as evidenced by increased contact angle and dynamic mechanical analysis results. Overall, the study demonstrated that silane-treated hybrid bio composites offer superior mechanical integrity, reduced moisture uptake, and improved thermal resistance. These findings highlight their potential for sustainable applications in automotive components, building panels, prosthetic sockets, and orthotic supports, contributing to lightweight and eco-friendly material development. This sustainable silane-treated hemp and bio-filler composite demonstrates potential as a next-generation material for lightweight biomedical support and rehabilitation applications in disability research.