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

In this paper, the foamed polylactic acid (PLA) composites with different ratios of titanium dioxide (TiO 2 ) 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/TiO 2 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 TiO 2 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.