Thermal Conductivity of Polymer Composites With Geometric Characteristics of Carbon Allotropes

Effect of the sizes and shapes of the diverse carbon allotropes such as carbon black, carbon nanotube, graphene nanoplatelet, graphite, pitch-based carbon fiber (PCF), and expanded graphite (EG) on the thermal conductivity of polymer composites is investigated. Effective improvement of the thermal conductivity of composites with microsized one-dimensional (1D) PCF and EG including the intercalation spacing is observed due to efficient formation of thermal transfer networks and little phonon scattering at the interfaces by the reduction of the interfaces. The excellent bulk and in-plane thermal conductivity of the composites with 20 wt% EG fillers of 1.9 and 6.7 Wm⁻¹K⁻¹ is observed.