TG–MS study on the effect of multi-walled carbon nanotubes and nano-Fe2O3 on thermo-oxidative stability of silicone rubber

Abstract

In this work, an investigation was focused on how carbon nanotubes and nano-Fe2O3 improved the thermo-oxidative stability of silicone rubber (SR). A series of nanoparticles, including carbon nanotubes (CNTs), Fe2O3 with two different crystalline forms (α-Fe2O3 and γ-Fe2O3), a mixture of CNTs and γ-Fe2O3 (γ-Fe2O3 + CNTs), and γ-Fe2O3-modified CNTs (γ-Fe2O3 − CNTs), were involved in this article. Thermal degradation characteristics of SR samples filled with these nanoparticles were investigated through thermogravimetric analysis equipped with mass spectroscopy system (TG–MS), and the evolutions of prominent volatiles corresponding to different stages of decomposition were recorded. It was discovered that these nanoparticles affected the thermo-oxidative stability of SR in different ways. While CNTs had an effect of delaying every stage of the degradation of silicone rubber, Fe2O3 inhibited the oxidation of the side methyl, in which γ-Fe2O3 had better performance. γ-Fe2O3 − CNTs had the best effect on preventing the side methyl from degradation, which can be seen from the remarkable decreases in methanol, methanoic acid and methane by 58.91, 57.27 and 27.45 %, respectively. This effect was superior to CNTs, γ-Fe2O3 or a mixture of both at the same addition amount. Herein, the reason for the different performance of these nanoparticles, which make a profound contribution to further improvement in thermo-oxidative stability of SR, has been discussed.