Thermal and electrical behaviors of activated carbon-filled PLA/PP hybrid biocomposites

Abstract

Activated carbon-based composites are prominent thanks to their unique surface properties, high thermal and mechanical stability, and good electrical performance. They are also used to produce special-purpose hybrid composites in strategic sectors such as defense, military, microelectronic, and medical industries. Hence, this study was expected to enlighten the thermal and electrical effect of activated carbon (AC) on polylactic acid (PLA)/polypropylene (PP) hybrid biocomposites and determine the possible advantages of using compatibilizers in hybrid biocomposites between natural fiber and polymer matrix. AC was produced by combining chemical (pre-activation) and thermal activation (pyrolysis) techniques. The AC-filled hybrid PLA/PP biocomposites were manufactured by extrusion process followed by hot-press molding. Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, thermal conductivity analysis, and electrical resistivity were conducted to measure the thermal behaviors of the biocomposites. The results showed that the crystallization temperatures (Tc) of the hybrid biocomposites increased by about 5 °C with the addition of AC to the biocomposite blend. The thermal insulation properties of hybrid biocomposites were up to 40% higher performance compare to virgin polymers due to the porous nature of AC and natural fiber. The hybrid composites conduct electricity slightly by adding AC to the PLA/PP polymer matrix. Thanks to adding a compatibilizer to the composite, a filling effect on porosity was observed and electrical conductivity improved by up to 66% in some samples.