Effects of multi-walled carbon nanotube structures on the electrical and mechanical properties of silicone rubber filled with multi-walled carbon nanotubes

Abstract

The effects of structures of multi-walled carbon nanotubes (MWCNTs) on the electrical and mechanical properties of MWCNT-filled silicone rubber were studied. The four types of MWCNTs have similar surface chemical properties but different structural parameters, such as the length, aspect ratio (AR) and specific surface area (SSA). The results indicated that with decreasing SSA of MWCNTs, the tensile strength and electrical conductivity of silicone rubber/MWCNTs decrease, whereas the rebound resilience increases. A larger SSA promoted easier formation of a favorable conductive path in silicone rubber/MWCNTs. The viscoelasticity of silicone rubber/MWCNTs was analyzed using a cure characteristic and rubber process analyzer. The SSA is found to be a key factor that affects the viscoelasticity of silicone rubber/MWCNTs. Silicone rubber/MWCNTs that contain MWCNTs with a larger SSA showed stronger filler–rubber interaction and higher tensile strength. Meanwhile, a larger SSA promoted a stronger effect of viscosity of MWCNTs and decreased the rebound resilience of silicone rubber/MWCNTs.