Effect of lignin and TiO2 on the structure and properties of PLA composites: Combine of simulation analysis and experimental results

Abstract

In this paper, the foamed polylactic acid (PLA) composites with different ratios of titanium dioxide (TiO2) and lignin (Lg) are prepared. Molecular dynamics simulation analysis indicates that the fillers enhance the mechanical properties of the composites. The optimal foaming temperatures for PLA/Lg and PLA/TiO2 composites are found to be 110 and 100°C, respectively. The supercritical carbon dioxide foaming process is applied to get the foamed composites, and their mechanical and thermal properties are analyzed. The results show that the addition of TiO2 improves the melting point and compression properties of the PLA composites. Furthermore, the inclusion of Lg increases the molecular chain mobility, foaming multiplicity, and compression strength of the composite materials.