Sustainable Al 2 O 3 /TiO 2 -filled banana/bamboo hybrid epoxy composites for structural and tribological applications

This study prepared banana/bamboo hybrid epoxy laminates reinforced with Al 2 O 3 and TiO 2 nanoparticles for lightweight engineering applications. The composites were fabricated by hand lay-up followed by compression curing. Banana fiber mats were placed as the outer skins, while bamboo fibers treated with 5 wt.% NaOH were used as the core reinforcement. Four laminate systems were investigated: BB0, the unfilled control; BBA, containing 4 wt.% Al 2 O 3 and 1 wt.% TiO 2 ; BBT, containing 1 wt.% Al 2 O 3 and 4 wt.% TiO 2 ; and BBAT, containing equal 2.5 wt.% Al 2 O 3 and 2.5 wt.% TiO 2 . The ceramic-filled laminates showed better performance than BB0, confirming the reinforcing effect of metal-oxide nanoparticles. Among all samples, BBAT provided the most balanced properties. It reduced water absorption from 23.5% in BB0 to 18.9% after 192 h, giving a 19.6% decrease in water ingress. BBAT also recorded tensile strength of 87 MPa, flexural strength of 138 MPa, impact strength of 9.6 kJ/m 2 , hardness of 88 Shore D, storage modulus of 4112 MPa, and Tg of 17.26°C. Thermal results showed that BBT had the highest degradation temperatures, while BBA produced the highest residual char and best tribological response. Microscopy confirmed improved interfaces and controlled wear, supporting sustainable lightweight composite applications.