Thermoplastic bio-composites from natural Samanea Saman fillers loaded HDPE: Mechanical, thermal, and structural analysis

This study explores the potential of biodegradable Samanea saman (SS) flower fillers as reinforcements in high-density polyethylene (HDPE) composites, fabricated using injection molding techniques at various filler concentrations. Surface morphology and elemental composition were analyzed using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Spectroscopy (EDX), revealing a composition predominantly of Carbon (88.04 %), along with Oxygen, Silicon, Chlorine, Potassium, Calcium, Sodium, and Bromine. The crystal structure of the fillers was identified as orthorhombic via X-ray diffraction (XRD), and the crystallite size was measured at 62.78 nm. Thermal stability assessments conducted through Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) indicated stability up to 210 °C before degradation occurred. Mechanical properties were optimized at a filler content of 40 wt% for Shore D hardness (63.5 ± 0.5 SHN) and compressive strength (25.5 ± 0.5 MPa), and at 30 wt% for tensile (23.5 ± 0.5 MPa) and flexural strength (19.5 ± 0.5 MPa). These results suggest that SS-HDPE composites offer a viable, environmentally friendly alternative for non-load-bearing applications, potentially reducing HDPE usage by up to one-third. • The method used injection molding to create composites with biodegradable Samanea saman flower fillers. • Applied EDX and FESEM characterized the composite surfaces and elemental composition. • The results showed that elements such as carbon and oxygen were predominant, with composites stable up to 210 °C. • The highest mechanical strengths were observed at higher filler concentrations. • The study demonstrates potential for reducing plastic use and enhancing environmental sustainability.