Development of green polystyrene composites using Citrus sinensis biochar filler

This research explored the characteristics of polymer composites reinforced with orange peel biochar. The composites were created using the hand lay-up method with different filler ratios, cured at ambient temperature, and analyzed with various analytical techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy (EDX). SEM images showed that roughness increased with higher filler percentages. FTIR analysis detected functional groups like OH, COOH, and aromatic compounds in the composites, primarily inheriting these groups from the resin. Elemental analysis using EDX indicated that the composites contained carbon, oxygen, silicon, aluminum, and potassium. Among these elements, only the carbon concentration demonstrated a linear increase with rising filler levels, with the composite containing 40% biochar achieving the highest carbon content at 84%. Hardness testing showed that the physical strength of the composites increased as the polystyrene resin matrix was reinforced, with the 40% biochar composite exhibiting a maximum hardness value of 296 N. These results indicate that adding biochar not only enhanced the properties of polystyrene-based composites but also reduced their environmental impact.