Effects of size distribution and surface treatments of seashell particles on flexural properties of seashell/epoxy composites

Abstract The present research, conducted with meticulous attention to detail, aims to investigate the use of seashell waste, mainly composed of CaCO₃, as a bio‐filler for polymers. This study experimentally studies the influences of seashell bio‐filler on the flexural properties of seashell powder/Epoxy composites. Effective surface modification can lead to optimum particle dispersion and may improve the interfacial interaction between the particles and the matrix by enhancing their interfacial compatibility. Surface treatments are applied to the seashell particles using several coupling agents to identify a suitable silane agent for the components of the composites. A proper fabrication method is determined by considering the factors that affect the mechanical properties of seashell/epoxy composites, such as particle size, filler distribution, and strength of interfacial adhesion. By applying surface modification to seashell particles using 3‐Aminopropyltrimethoxysilane, seashell/epoxy composites containing 2 wt.% modified seashell achieve a 66% improvement in flexural strain energy and a negligible improvement of 5.2% in bending strength compared to the pure polymer. Highlights The fabrication process of seashell powder/epoxy composites was presented. Flexural properties of seashell powder/epoxy composites were characterized. Effects of particle size and surface modification were considered. Micromechanical theory was used to predict the bending modulus. Surface modification improved the flexural strain energy of composites.