Modification of graphene with silica nanoparticles for use in hybrid network formation from epoxy, novolac, and epoxidized novolac resins by sol-gel method: Investigation of thermal properties

Thermal stability of hybrid composites prepared from epoxy, novolac, and epoxidized-novolac resins and also modified graphene oxide (SFGO) was studied. SFGO was prepared by covering graphene oxide with silica nanoparticles and a bifunctional silane modifier. The first hybrid was prepared from SFGO and silane-modified epoxy resin. The second one was prepared from SFGO, and silane-modified epoxy and novolac resins. The third hybrid was formed from SFGO, silane-modified novolac, and epoxidized novolac resins. Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) results showed that modification of graphene oxide was carried out successfully. TGA results show that degradation temperature and char residue of resins were increased through their incorporation into hybrid network with SFGO. In addition, the most increase of char residue was observed for the hybrid composites formed from SFGO and modified novolac and epoxy resins.