Banknotes residues and thermoplastic starch as sustainable reinforcements for LDPE-based agricultural composites

This study examines the development and characterization of composites comprising low-density polyethylene (LDPE), thermoplastic starch (TPS), and cellulose fibers sourced from recycled banknotes (BR). The composites were fabricated using extrusion and injection molding techniques, followed by an evaluation of their morphological, thermal, mechanical, and water absorption properties. The inclusion of BR fibers enhanced the mechanical performance of LDPE, notably improving tensile strength and elastic modulus, while the hydrophobic treatment of the fibers ensured minimal water absorption. The incorporation of TPS increased the composites' biodegradability potential but reduced tensile strength and increased water absorption due to its hydrophilic nature. Scanning electron microscopy revealed strong interfacial adhesion between the fibers and matrix and confirmed the complete dispersion of starch in TPS-containing samples. Thermogravimetric analysis highlighted the thermal stability of the composites and identified distinct degradation stages corresponding to the matrix, TPS, and fibers. These results indicate that the developed composites offer a viable solution for agricultural applications, balancing mechanical performance and environmental sustainability.