Improved thermal stability of phenolic resin by graphene-encapsulated nano-SiO₂ hybrids

Phenolic resin (PR) modified with hybrids of reduced graphene oxide (RGO)-encapsulated nano-SiO₂ (SiO₂–RGO) was prepared by a simple method. The synergistic effect of RGO and nano-SiO₂ was achieved in the thermal decomposition of the modified PR. Thermal stability of SiO₂–RGO and the modified PR was evaluated by thermogravimetric analysis (TG). With 1 mass% loading of SiO₂–RGO, the maximum decomposition temperature (T_dmax) of the modified PR was increased by 32.50 °C and the residual mass at 800 °C was increased by 6.54%. The structure of the resin char was characterized to study the mechanism of ameliorative thermal stability. SiO₂–RGO hybrids were conducive to induce the PR to form graphitized carbon in the pyrolysis process. Thus, SiO₂–RGO can facilitate the application of PR in the fields of heat insulation and ablation resistance.