A comprehensive study on the effect of small rates of walnut shell and talc fillers on the thermal,mechanical, and morphological properties of epoxy hybrid composites

Abstract

AbstractEpoxy-based composites, valued for their cost-effectiveness and remarkable mechanical properties, attract considerable attention from researchers in academia and industry. This study explores the impact of low concentrations (1% to 3%) of walnut shell (WS) and talc additives on the density, water absorption, and mechanical (tensile, three-point bending, impact, hardness) as well as thermal (TGA, DSC) properties of epoxy composites. While prior research has extensively covered epoxy composites with high concentrations of walnut shell and talc, their utilization in lower concentrations remains underexplored. Findings highlight the substantial influence of incorporating low percentages of walnut shell and talc on the Tg temperatures of epoxy composites, with talc reducing Tg temperature and WS elevating it. TGA tests reveal that both WS and talc contribute to increased Tmax temperature and residue content compared to pure epoxy. Mechanical properties exhibit variations based on filler type and amount, with walnut shell enhancing the elastic modulus and talc decreasing it compared to pure epoxy. Impact resistance sees significant reductions related to particle size. Talc boosts density, while WS has a more pronounced effect on hardness. Water absorption tests demonstrate higher water absorption in WS-containing epoxy composites. Glossiness and surface roughness undergo changes, with talc increasing roughness and decreasing glossiness. In conclusion, even minor filler percentages noticeably impact epoxy composite properties compared to pure epoxy, providing avenues for customized modifications, particularly with challenging or costly fillers, offering viable alternatives for researchers in diverse fields.