Aging effects on thermal and dielectric properties of polypropylene/magnesium aluminate nanocomposites

Abstract

This paper reports on the effects of aging on thermal and dielectric properties of unfilled polypropylene and polypropylene nanocomposites containing 2 wt% and 5 wt% of magnesium aluminate nanofiller. These evaluated samples were prepared using a melt blending technique. A hydraulic laboratory press was employed in order to obtain 100 µm thick sample. Two different aging conditions were considered, namely, unaged (as a reference) and aged at 140 °C. The evaluated samples were then characterized using differential scanning calorimetry (DSC) for thermal analysis. Meanwhile, the dielectric strength was determined based on DC electrical breakdown tests. The experimental results show that, aging the samples at 140 °C changed the thermal behavior of all evaluated samples. Specifically, the melting temperature (Tm) increased when the samples were aged at 140 °C. Meanwhile, the DC breakdown strength of unfilled polypropylene reduced significantly after aging at 140 °C when compared to polypropylene nanocomposites.