Microstructure and rheological behavior of nanoclay-filled polyethylene (PE)/ethylene vinyl acetate (EVA) blends

Dynamic shear flow experiment along with transmission electron microscopy (TEM), small angle x-ray scattering (SAXS) and scanning electron microscopy (SEM) analyses were performed for PE- and EVA-rich blends containing a kind of Montmorillonite organoclay namely Cloisite 15A. The TEM observations revealed that clays were localized in both PE and EVA phases as well as at the interface of blend samples. The localization and the degree of dispersion of clay within nanocomposite samples were also studied by analyzing the changes in the linear viscoelastic rheological properties. These changes were discussed using the power law expression. The changes in the n value, the shear thinning exponent of power law expression, due to the incorporation of a relatively high content of clay to the EVA-rich blend, in contrast to PE-rich blend, indicated a better dispersion of clay in the EVA-rich blend. SEM analysis showed that the organocaly was capable of performing the compatibilizer role for both PE- and EVA-rich blends.

Keywords:

Nanocomposite , blend , rheology , polyethylene , polyethylene vinyl acetate