Improved thermal conductivity of polycarbonate composites filled with hybrid exfoliated graphite/multi-walled carbon nanotube fillers

Abstract

The thermal conductivities of polycarbonate (PC) composites filled with carbon fillers, including carbon black (CB), multi-walled carbon nanotubes (MWCNTs) and exfoliated graphite (EG), were studied. EG filler provided substantially greater thermal conductivity enhancement when embedded into PC matrix compared with CB and MWCNTs at the same loading. To further improve the thermal conductivity of PC composite, a hybrid EG/MWCNTs filler was used. When the hybrid filler loading was 10 mass%, the radio of EG: MWCNTs was 9:1, and the thermal conductivity of PC composite showed a maximum value of 1.19 W m−1 K−1 higher than that filled with EG or MWCNTs alone, indicating that the combination of EG and MWCNTs demonstrated a synergistic effect for the thermal conductivity enhancement of PC. EG/MWCNTs/PC composite with thermal conductivity >5 W m−1 K−1 was fabricated when the filler content was 40 mass%, which would widen its field of applications in electrons, LED lamps and aerospace.