Effects of multi-walled carbon nanotubes on char residue and carbothermal reduction reaction in ethylene propylene diene monomer composites at high temperature

Abstract

Mechanistic investigation of the effect of nanofillers on the ablation of composites is essential to meet the demand for high-performance ablative composites. Ethylene propylene diene monomer (EPDM) composites with and without 5 wt% multi-walled carbon nanotubes (MWCNTs) are prepared, and their ablation rates are tested using a solid rocket motor. The carbothermal reduction reaction during ablation is studied using a high-temperature tube furnace. The carbothermal reduction reaction of silica at high temperature results in a large consumption of char, and is an important reaction affecting the ablation process. The addition of MWCNTs increases the char residue of EPDM composites. MWCNTs can enhance the rate-limiting reaction, thereby reducing the released gas and increasing the production of SiC. The network structure of MWCNTs in char has a directional effect on the in-situ formation of SiCw, which can improve the ablation resistance of composite.