Poly (lactic acid)/ poly (butylene succinate) (PLA/PBS) nanocomposites for thin film applications

PLA/PBS/Cloisite 30BX (organically modified MMT) clay nancomposites were prepared by using melt extrusion method. The polymer ratio was maintained at 80% and 20% wt (PLA:PBS) for all the nanocomposites and clay content was varied from 1, 3, 5, 7 and 10 wt%. Electron microscopy (TEM) morphological, calorimetry (DSC) thermal and gas barrier properties of these nanocomposites were evaluated. We also report on a permeability model based on nanoclay sheet length and its relative orientation within the polymer matrix. We found that nanocomposite having 1 wt% of clay attain mixed morphology of intercalated and exfoliated structure, while some clusters or agglomerated particles were detected for nanocomposites having 3 and higher wt% of clay content. Calorimetry investigations revealed the fundamental glass transition behaviour of the nanocomposites and influence of clay exfoliation. Oxygen gas barrier and water vapour transmission properties were measured and experimental values were compared with Bhardwaj model. We found that gas barrier property improved significantly as compared to water vapour.