Upcycling Oyster Shell Waste into Sustainable Polypropylene Biocomposites: Synthesis and Characterization

There is a growing interest in the application of natural and waste-derived biofillers for reinforcing thermoplastic polymers, as their utilization helps to reduce the carbon footprint and therefore enhances sustainable development. The aim of this study is to synthesize and characterize a biocomposite based on PP reinforced with OS particles derived from biomass in order to reduce plastic shrinkage after injection molding and to assess their viability as environmentally sustainable materials. The addition of OS particles (10 wt.% and 30 wt.%) significantly reduces the crystallinity of the PP, thereby improving its rigidity, its tensile strength, and its thermal stability. DSC analysis and TGA validated superior thermal properties, whereas mechanical and dynamic mechanical assessments indicated augmented stiffness and energy storage capacity with increasing filler content. The utilization of OS waste, abundant in CaCO3, facilitates a circular economy model, minimizing environmental impact and enhancing waste valorization. The findings underscore the viability of PP/OS biocomposites as sustainable substitutes for traditional mineral-filled polymers in engineering applications.