Effect of hybrid MMT and ZnO nano fillers on thermomechanical and vibrational behaviour of okra fiber reinforced polymer composite

Abstract

Polymer composites, fortified with nano-particles offers exceptional properties for diverse applications. This study explores the mechanical properties of okra-based composites focusing on the incorporation of zinc oxide (ZnO) fillers. Okra fibers extracted and treated with sodium hydroxide are combined with epoxy resin as the matrix along with montmorillonite nano clay (1.5 wt. %) and varying concentrations of ZnO fillers (2, 4 and 6 wt.%). Mechanical tests including tensile, flexural, impact, compression and interlaminar shear strength as well as dynamic mechanical analysis and vibration analysis were conducted. Results indicate that ZnO nanoparticles significantly enhance the mechanical strength of the composites, with optimal improvements observed at lower filler concentrations. However, excessive ZnO addition beyond a certain threshold led to diminished returns due to potential agglomeration. Alkaline treatment of okra fibers further improves the mechanical properties by enhancing fiber-matrix adhesion and reducing moisture absorption. Dynamic mechanical analysis reveals enhanced stiffness and damping characteristics with ZnO incorporation contributing to improved energy dissipation and reduced vibration amplitudes.