The effect of MWNTs on the microstructure of resin carbon and thermal conductivity of C/C composites

Multi-walled nanotubes were added into furan resin. Unidirectional carbon/carbon preforms were densified with the nanotube-doped furan resin by impregnation–carbonization cycle. The effects of Multi-walled nanotubes on the microstructure of resin carbon and thermal conductivity of carbon/carbon composites were investigated. The results show that Multi-walled nanotubes can induce the ordered arrangement of planar carbon microlites in resin carbon during high-temperature treatment and enhance the graphitization degree of resin carbon. Small amount of Multi-walled nanotubes in resin carbon can enhance the thermal conductivity of C/C composites evidently, especially the thermal conductivity vertical to the direction of fiber axis, due to the improvement of microstructure of resin carbon. Excess Multi-walled nanotubes in resin are disadvantageous to the enhancement of thermal conductivity instead, because they are difficult to disperse and easy to agglomerate, resulting thermal resistances in carbon matrix.