EFFECTS OF OYSTER SHELL POWDER AND CHEMICAL TREATMENT ON THE MECHANICAL PROPERTIES OF EXPANDED POLYSTYRENE/SAWDUST COMPOSITE.

The global plastic waste menace has evolved over the years and has contributed to increased pollution rates. The lack of alternative uses for plastic waste results in mismanagement and landfilling. Hence, it is imperative that the circularity of the plastic value chain be investigated, and a strategy to close the loop be determined. Thus, we seek to develop a plastic/sawdust composite from expanded polystyrene and sawdust waste and explore the role of the sawdust fiber filler and oyster shell powder (OSP) additive in the enhancement of the composite’s physical and mechanical properties. The bulk density and water absorption of the composites were determined conventionally. The tensile strength, modulus of elasticity, and rupture were measured. The analyzed data indicate that different OSP loadings enhanced the physical and mechanical properties. The treatment of the sawdust enhanced the tensile strength more than the OSP loading, with the best performing composite being without OSP loadings. Therefore, the life cycle of polystyrene waste can be prolonged through the secondary use in plastic/ sawdust composite whose physical and mechanical properties can be enhanced by the addition of 0.5% or 0.7% OSP loadings and the tensile strength can be improved by the chemical treatment of sawdust fibers