Multi-walled carbon nanotubes as secondary fibre fillers for property improvement of short carbon fibre-reinforced silicone rubber

To improve the properties of room temperature vulcanized (RTV) silicone rubber, functional multi-walled carbon nanotubes (MWCNTs) and short carbon fibres were added into the RTV silicone rubber as hybrid fibre fillers. The functionalized MWCNTs were characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The mechanical, thermal and ablative properties of the fabricated RTV silicone rubber composites were investigated. Their properties were enhanced by adding the functionalized MWCNTs with appropriate contents. The tensile strength and tear strength of the composites are improved from 4.0 MPa and $$20.3\hbox { kN m}^-1$$ to 4.3 MPa and $$21.3\hbox { kN m}^-1$$, respectively, when the MWCNT content increased from 0 to 0.5 phr. In addition, the decomposition temperatures at the onset point and 50% mass loss increased from 493.4 and $$564.4{^\circ }\hbox {C}$$ to 498.8 and $$612.4{^\circ }\hbox {C}$$, respectively. The mass and line ablation rates also decreased from $$0.062\hbox { g s}^-1$$ and $$0.148\hbox { mm s}^-1$$ to $$0.059\hbox { g s}^-1$$ and $$0.145\hbox { mm s}^-1$$, respectively.