Development and characterization of surface-treated Ailanthus excelsa and waste polyethylene terephthalate powder reinforced polyester composites

This study investigates the potential of incorporating recycled Polyethylene Terephthalate (PET) powder as a secondary reinforcement in natural fiber-based polymer composites to address the need for sustainable, high-performance materials. Although natural fiber composites have gained attention, limited work has explored the combined effect of silane-treated Ailanthus excelsa fibers and PET waste fillers on long-term mechanical and tribological performance. Composites containing 40 vol.% surface-modified A. excelsa fibers, and varying PET powder contents (1–5 vol.%) were fabricated using the hand lay-up technique and evaluated according to ASTM standards. Results indicate that PET addition significantly influences performance, with the 3 vol.% PET composite showing optimal mechanical strength and fatigue resistance, while the 5 vol.% PET composite exhibited superior creep resistance, hardness, and wear behavior. Microstructural analysis confirmed improved interfacial adhesion due to silane treatment, contributing to enhanced load transfer and durability. The findings demonstrate that controlled incorporation of recycled PET can effectively tailor the mechanical and tribological properties of natural fiber composites. This work highlights a viable pathway for valorizing polymer waste while developing sustainable composite materials suitable for structural and semi-structural applications in automotive, construction, and aerospace sectors.