Morphology development, melt linear viscoelastic properties and crystallinity of polylactide/polyethylene/organoclay blend nanocomposites

Abstract

Polylactide/polyethylene blends (PLA/PE) and their nanocomposites were prepared via the melt blending process. The effects of organoclay, compatibilizer (PE-g-MA), and PE content on morphology, linear viscoelastic properties of the melt and cold crystallization of the samples have been studied. The Palierne model is applied to predict the rheological behavior of unfilled blends. It implies that there is a quantitative agreement between model and experimental data for low PE content blend. From WAXD and the rheological behavior, it is shown that organoclay exhibits a higher extent of intercalation and dispersion in PLA/PE/organoclay nanocomposite than in PLA/organoclay nanocomposite. The DSC results present that the addition of compatibilizer into blend nanocomposite increases cold crystallization temperature of PLA by about 3°C. This can be explained by the role of compatibilizer in transfer of a part of organoclay from PLA matrix to droplets resulting in increase of PLA chain mobility and, therefore, slightly greater cold crystallization temperature.