Investigation of the Thermal, Physical, and Microstructural Properties of Polymeric Composites Bio-Reinforced with Charcoal Fines

Incorporating solid waste into polymeric matrices has proven effective in developing composites with enhanced mechanical and thermal properties. This study investigates a composite based on recycled high-density polyethylene (HDPE), reinforced with fine charcoal particles, assessing its thermal, microstructural, and density properties. Two processing methods (compression molding and extrusion) and four charcoal concentrations (0%, 5%, 10%, and 15 wt%) were evaluated. Thermal characterization was performed using thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). The microstructure was analyzed through scanning electron microscopy (SEM) and X-ray diffraction (XRD), while the density was determined via X-ray densitometry. SEM revealed increased porosity with charcoal addition. The thermal properties and crystallinity of the composites were not significantly affected by variations in the manufacturing method or charcoal concentration. FTIR analysis identified characteristic peaks, while TGA indicated mass loss between 400 and 500 °C, with a maximum decomposition temperature of 487 °C. XRD confirmed the semicrystalline structure typical of HDPE. Thus, incorporating charcoal residues can reduce the use of fossil-based materials while providing a sustainable application for industrial waste.