Improvement of ablation resistance of epoxy composites reinforced with low concentrations of multi walled carbon nanotubes

Abstract

Ablative materials are used as a thermal protection system for objects exposed to extreme friction and ultrahigh temperature. The ablation resistance of epoxy resin reinforced with multi-walled carbon nanotubes (MWCNTs) at low concentration was investigated. The ablation resistance improved with increasing MWCNT content. The linear ablation rate of 0.5 wt% MWCNT was 30.7% less than that of neat epoxy. On the ablated surface, curved cylinder structures with superior strength to the surrounding matrix were formed around MWCNTs which acted as nucleation sites. X-ray diffraction and Raman spectroscopy revealed the formation of near-graphite structures around MWCNTs in the non-graphitizable epoxy matrix. In conclusion, MWCNTs at low concentration could facilitate the formation of near-graphitic structures in quite large region of epoxy matrix, so dramatically enhanced ablation resistance.