Polylactide/montmorillonite nanocomposites in-situ polymerization and characterization

High molecular weight polylactide/montmorillonite nanocomposites were obtained through in-situ melt polycondensation method in which the montmorillonite (MMT) was added after dehydration and before the polycondensation. The results of XRD and TEM show that exfoliated nanocomposites are obtained when the addition of montmorillonite is 0.5% (mass fraction), and both intercalated and exfoliated structures are obtained when it is 1%. When the mass fractions of montmorillonite are 0.5% and 1%, the tensile strength, elongation at break and impact strength of the nanocomposites are better than those of pure polylactide (PLA). When they are higher, these mechanical properties become worse. SEM image of PLA-MMT0.5 (the mass fraction of montmorillonite is 0.5%) shows a fracture toughness characterization.