Dielectric Properties of Banana Fiber Filled Polypropylene Composites: Effect of Coupling Agent

Abstract

The goal of this article is to examine the effect of MAPP (malic anhydride grafted polypropylene) used as a coupling agent on the dielectric properties of polypropylene filled banana fiber composites. Banana fiber reinforced polypropylene composites were prepared by using twin screw extruder and injection molding apparatus. The dielectric parameters of both coupled and uncoupled composites were calculated in the experiment with temperatures from 30 °C to 150 °C in steps of 10 °C and frequencies in the 20 Hz to 10 MHz range. Composites prepared using a coupling agent and increasing the content of the banana fiber was found to have a major change in dielectric properties. Compared to un-coupled composites, the dielectric constant (ε′) has increased by up to 15–20% in coupled composites. Various polarization mechanisms can be related to boosting dielectric properties in coupled composites. Anomalous behavior in the transition region was shown by the dissipation factor in both composites. Low electrical conductivity has been demonstrated by coupled composites and can therefore be used for many insulating applications. Using TGA study, degradation temperatures of banana fiber, PP and composites were examined. Scanning electron microscopy morphological studies have shown that MAPP integration helps to achieve proper adhesion between banana fiber and polypropylene.