Mechanical Analysis of Hybrid Polymeric Composites Reinforced with Recycled Eucalyptus and Montmorillonite Clay

Recent advances in polymeric composites emphasize the incorporation of natural and mineral fillers to enhance sustainability while maintaining mechanical performance. Studies have shown that lignocellulosic residues and nanostructured clays can improve stiffness and thermal stability, although interfacial compatibility remains a key challenge. This study investigates the mechanical behavior of epoxy composites reinforced with eucalyptus powder and montmorillonite clay, aiming to develop sustainable materials with reduced environmental impact. Formulations containing 5%, 10%, and 20% by volume of each particulate, as well as hybrid combinations, were produced and tested for impact, flexural, and compressive strength. Higher particulate contents were not explored, as fractions above 20% considerably increased viscosity, hindering proper mixing and specimen fabrication. Scanning electron microscopy (SEM) revealed irregular morphologies and heterogeneous dispersion of both fillers. The reduction in impact strength observed across all formulations was mainly attributed to poor interfacial adhesion and void formation, as no chemical or surface treatments were applied to enhance compatibility between the particulates and the epoxy matrix. Conversely, compressive strength improved at low filler contents (5-10%), suggesting a more efficient load transfer under compressive stress. Composites with up to 10% particulate presented a viable balance between mechanical performance and sustainability, showing potential for non-structural applications such as panels, coatings, and eco-friendly construction components. Overall, the results highlight the feasibility of using natural and mineral particulates as sustainable reinforcements, albeit with performance constraints at higher loadings.