The Effect of OH-Modified Nanoclays Fillers on the Compatibility and Properties of Polypropylene/Poly (Ethylene Oxide) Blends

This study evaluated the possibility of improving the compatibility and properties of immiscible polymer blends made of polypropylene (PP) and poly (ethylene oxide) (PEO) by the incorporation of nanoclays as additives. The selected nanoclay type was Cloisite® 30B, which was organically modified with OH group. The blends were prepared by melt-blending and characterized by various techniques, with fixing the PP/PEO mass ratio at 70/30 but with varying the loading of nanoclays up to 10 wt%. Based on mechanical testing, for nanoclays loading up to 5 wt%, the elastic modulus increased considerably with increasing the loading of nanoclay while the elongation at break and the toughness were not negatively affected. Rheological testing showed the increase of storage modulus of the blends as the loading of nanoclays increased, with clear plateau observed at low frequency range for samples filled with 5 and 10 wt% of nanoclays, indicating a network formation of nanaoclays for the filled samples. Scanning electron microscopy confirmed that the presence of nanoclays in the PP/PEO blend reduced the domain size of the dispersed phase (PEO) considerably. As revealed by differential scanning calorimetry, nanaoclays had a sharp effect for suppressing the fractionated crystallization of PEO in the PP/PEO blend. These results suggested that nanoclay up to 5 wt% loading, in addition to play a conventional role of reinforcing filler, could also play simultaneously the role of efficient compatibilizer for PP/PEO blend.