Abstract
The paper examines the use of waste eggshells as a valuable biofiller for modifying plasticized poly(vinyl chloride) (PVC). The raw ES was characterized using TGA, FTIR, particle size analysis, and XRD. The effects of ES on the processing, mechanical and thermal properties, density, porosity, and colour of PVC matrix composites were evaluated compared to pPVC/CC produced using the same methodology. It was found that pPVC/ES exhibits different processing properties to pPVC/CC. The mechanical properties of PVC/ES are slightly lower than those of pPVC/CC at concentrations up to 20 phr. However, at 30 phr and 40 phr, the differences in the mechanical properties of composites with both CC and ES are very similar, and the values are within the designated standard deviation of the measurement. The mechanical properties of PVC/ES do not limit their potential applications. When using eggshell (ES) as a filler, improvements in tensile strength (t(ts)) were observed, ranging from 38% to 61% compared to the unfilled matrix and from 35% to 54% compared to pPVC/CC with an equivalent amount of filler. Although ground eggshells have similar insulating properties to calcium carbonate (CC), they are more effective at scavenging chlorine (Cl•) released during the initial stages of decomposition. This effectiveness helps to slow down the breakdown of PVC, as the eggshells maintain their porous, sponge-like structure when used as a filler.