Fabrication and characterization of organically modified layered double hydroxide/poly (lactic acid) nanocomposite by sonication-assisted solution compounding method

Abstract

The superior physicochemical properties of layered double hydroxides (LDHs) sets them apart from traditional polylactic acid (PLA) fillers. However, achieving efficient dispersion of LDHs within the PLA matrix poses a challenge in the fabrication of PLA/LDHs nanocomposites. In order to enhance the dispersion of LDHs in the PLA matrix and improve their compatibility with PLA, in this study sodium stearate (SS) and sodium dodecyl sulfate (SDS) were used as surface modifiers and intercalation modifiers for LDHs, respectively. Notably, the strategy of intercalation-surface combined modification for LDHs nanofillers in PLA was explored for the first time. Furthermore, the resulting PLA/LDHs nanocomposites were prepared via a sonication-assisted solution compounding method. The results indicate that the addition of LDHs modified through different methods and concentrations affects not only the thermal properties and crystallinity of the PLA/LDHs composites, but also improves the tensile strength and elongation at break of PLA. Notably, the PLA_LDH_SDS_SS_9% composite exhibited an elongation at break that was 230% higher than neat PLA. This study fills a research gap in the field of PLA/LDHs nanocomposites and establishes a significant foundation for the future preparation and application of these.