Preparation and characterization of novel clay/PLA nanocomposites

Abstract In this work, the preparation of a polylactide-nanocomposite material using, as a filler, the smectite-rich clay fraction of a Cenozoic formation in Braganca, Portugal, is introduced as a promising and cost-efficient approach to nanocomposite preparation. Nanocomposites of a mixed morphology were achieved, as confirmed via the visual observation of the dispersion and intercalation of the clay layers by TEM imaging; mostly analogous morphologies were achieved through the use of reference clay mineral, montmorillonite SWy-2, for the preparation of similar nanocomposites. With both sets of nanocomposites, TGA results indicated an enhanced thermal stability, as compared to neat PLA. In the case of the nanocomposites prepared using the clay fraction from Braganca, this effect was observed at temperatures at which 25% weight loss was observed. On the other hand, in the case of the SWy-2-based nanocomposites, the improved thermal stability effect was evident at higher temperatures, at which 50% weight loss took place. The complementary thermal stability effects provided by the two sets of nanocomposites prepared, combined with their comparable morphology, are promising results towards a feasible and contemporary approach to nanocomposite preparation, worthy of further research.