Structure and Breakdown Properties of Polypropylene-based Nanocomposites

This work was performed to investigate the effects of different nanofillers on the structure and dielectric properties of polypropylene (PP) nanocomposites. This work considered studying three types of nanofillers, namely, magnesium aluminate (MgAl 2 O 4 ), calcium carbonate (CaCO 3 ), and surface-modified calcium carbonate (CaCO 3 T). PP nanocomposites containing MgAl 2 O 4 , CaCO 3 , and CaCO 3 T nanofillers were prepared using a Brabender melt mixer. The samples were melt pressed using a hydraulic laboratory press at 180 °C to produce thin-film samples of 100 µm thick. The prepared samples were subjected to Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) for chemical and morphological analysis. Meanwhile, the DC breakdown test was carried out to analyzed the dielectric properties of the evaluated samples. The results showed that PP/MgAl 2 O 4 nanocomposites possessed lowered breakdown strength compared to unfilled PP. In contrast, PP/CaCO 3 nanocomposites possessed a higher breakdown strength over PP/MgAl 2 O 4 nanocomposites. Meanwhile, PP/CaCO 3 T nanocomposites possessed the highest breakdown strength among the nanocomposites. Possible mechanisms governing these property changes are discussed.