This study presents a hybrid natural fiber–reinforced epoxy composite developed for improved acoustic, thermal, and tribological performance. The novelty lies in the quaternary fiber hybridization palm (PM)/cocho (CO)/wood (WO)/tamarind (TD) combined with nano solid lubricant coatings to achieve multifunctionality in a single material. The hybrid composite showed excellent acoustic behavior, with the sound absorption coefficient increasing from 0.23 to 0.75 at 6000 Hz, corresponding to an improvement of over 220%. Thermal conductivity and thermal diffusivity were reduced by 24.08% and 27.27%, respectively, while thermal resistance increased by 31.74% and the coefficient of thermal expansion decreased by 27.59%, indicating improved insulation and dimensional stability. Tribological results revealed that graphene outperformed Titanium dioxide (TiO 2 ) and Silicon dioxide (SiO 2 ), providing up to 31.44% higher wear resistance and a drastic reduction in friction (80–100%) due to the formation of a stable self-lubricating transfer film. These results demonstrate that the developed composite is a lightweight, eco-friendly, and multifunctional material suitable for noise control, thermal insulation, and wear-resistant engineering applications.
Velayutham et al. (Tue,) studied this question.