Mechanical Properties of Recycled Polypropylene and Rubber Waste Composites for Sustainable Material Application

In recent years, polymeric and elastomeric wastes such as polypropylene and scrap rubber have been recognized as major environmental pollutants due to their resistance to natural decomposition, which poses significant risks to the ecosystem. Therefore, developing effective strategies for recycling and reusing these materials is of growing importance. This study investigates the feasibility of mixing recycled polypropylene (rPP) and waste rubber to develop a new composite material with improved mechanical performance. The study began by preparing mixtures of rPP and rubber waste at three different weight ratios of 90:10, 70:30, and 50:50 wt% for the identification of the optimal composition that offers desirable mechanical properties. The prepared composites were then fabricated via hot pressing and subsequently subjected to tensile and flexural strength tests. The results showed that the 90:10 wt% rPP–rubber composite had the highest tensile strength at 6.17 MPa, whereas the 70:30 wt% composition had the best flexural strength at 19 MPa. These results indicated that an optimal balance between stiffness and toughness is required. Overall, the 70:30 wt% blend demonstrated a good balance of strength and flexibility. These findings highlight the potential of utilizing polymer and rubber wastes in developing value-added materials for construction applications such as wall panels, roofing sheets, and flooring components. This supports the principles of a circular economy and reducing environmental pollution.