Flame retardance and thermal stability of carbon nanotube epoxy composite prepared from sol–gel method

Carbon nanotubes (CNTs) are functionalized by vinyltriethoxysilane (VTES) to incorporate the –O–C2H5 functional group and become VTES—CNT. The VTES—CNTs are added to the modified DGEBA epoxy resin that contains silicon to induce the sol–gel reaction. The final products are organic/inorganic nanocomposites. Thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) are used to study the thermal property of nanocomposites. The Tg was increased from 118 to 160 °C and char yield of composites that contained 9 wt% CNT at 750 °C was increased by 46.94%. The integral procedural decomposition temperature (IPDT) was increased from 890 to 1571 °C. The limiting oxygen index (LOI) and UL-94 tests were classified as the flame retardance. The LOI of composites was increased from 22 to 27 and the UL-94 changed from V-1 to V-0 when the contents were increased to 9 wt%. The nanocomposites had a higher char yield and were highly flame retardant. The products can meet to the requirements of halogen-free and phosphorus-free ecological flame retardant.