Influence of calcium carbonate reinforcement on mechanical properties and sustainability of hdpe-recycled plastic composites for industrial applications

Currently, the demand for sustainable materials has led to an interest in polymer composites filled with mineral fillers and recycled materials. High-density polyethylene (HDPE) is a potential matrix for green composite production due to its widespread application, excellent mechanical properties, ease of recycling, and high density. This study investigates the mechanical properties of HDPE composites containing different mix proportions of calcium carbonate (CaCO₃) and recycled plastic. The mechanical performance of composites was evaluated by testing their tensile strength, elongation at break, Young's modulus, hardness, flexural strength, flexural modulus, and impact strength. Inclusion of CaCO₃ in the matrix resulted in improved stiffness and rigidity of HDPE, with the Young's modulus increasing significantly to 1517.2 MPa for sample A3. However, with an increase in stiffness, there was a decrease in tensile strength and elongation at break, indicating a transition to a more brittle behavior. Samples containing a higher content of recycled plastic showed an increase in ductility and impact resistance, with sample A8 surpassing all others. The blends A9 to A12, which are the most balanced mixtures of HDPE, CaCO₃, and recycled plastic, offered the best compromise in terms of mechanical strength and flexibility. Sample A12 demonstrated good performance in terms of tensile strength (18.71 MPa), elongation at break (90%), Young's modulus (210 MPa), and impact strength (69.9 kJ/m²). The results of the current study support the idea that plastic waste can be recycled and used as components in functional materials, aligning with the sustainable development goals. Recycling plastic reduces landfill waste, conserves resources, and enables the creation of new products, thereby contributing to a more circular economy.