Abstract The increasing demand for advanced lightweight composites has driven significant interest in polymer-based materials for electrically conductive applications in electronics and high-voltage systems. This study investigates epoxy-based composites reinforced with graphite and carbon black, fabricated through speed mixing and hot pressing. The effects of total filler content, composition ratio, and graphite particle size on electrical conductivity were systematically analyzed. Optimized conditions significantly reduced volume resistivity, emphasizing the importance of filler morphology and distribution in forming effective conductive networks. The hybrid system containing 30 wt% large graphite particles and 15 wt% carbon black exhibited the lowest resistivity of 0.027 Ω·cm, compared to 0.406 Ω·cm for 45 wt% carbon black and 0.095 Ω·cm for 45 wt% graphite. This enhancement is attributed to the synergistic interaction between fillers, enabling the formation of a densely interconnected three-dimensional conductive structure. Furthermore, thermogravimetric analysis confirmed improved thermal stability, and infrared thermography demonstrated superior thermal transport properties in the hybrid composites. These results provide valuable insights for designing epoxy-based composites with enhanced electrical and thermal performance, supporting their application in next-generation electronic and high-voltage systems.
Kim et al. (Mon,) studied this question.