Investigating the Influence of Various Inorganic Fillers on Thermal, Fire Performance, and Mechanical Properties of Polylactic Acid

This study investigated the influence of zinc oxide (ZnO), titanium dioxide (TiO2), and calcium carbonate (CaCO3) on the material properties of PLA processed by melt compounding in a twin-screw extruder. The results demonstrated that the incorporation of ZnO and CaCO3 reduced the thermal stability of PLA. Furthermore, ZnO reduced the complex viscosity and tensile strength of PLA. In contrast, the addition of TiO2 maintained the thermal stability, complex viscosity, and mechanical properties of PLA. Moreover, it was observed that combining ZnO with TiO2 and CaCO3 preserved the mechanical properties of PLA. The findings underscore the significance of hybridization, as it enhanced the properties of PLA/ZnO nanocomposites. Among all the developed composites, ZnO/TiO2 demonstrated better performance, which could be attributed to the finer dispersion of the fillers observed by scanning electron microscopy. Overall, the findings demonstrate the potential of maintaining the properties of PLA in PLA/ZnO composites through the hybridization of inorganic fillers, particularly when prepared using melt processing.