Preparation of flame retardant and conductive epoxy resin composites by incorporating functionalized multi-walled carbon nanotubes and graphite sheets

This work reports our recent efforts on the preparation of functionalized multi-walled carbon nanotubes (f-CNTs) and its application in improving the fire, conductive, and mechanical performance of epoxy resin (EP) composites in combination with graphite sheets (GSs). The addition of hybrid carbon nanomaterials can effectively improve the mechanical properties of epoxy. Consequently, when the mass fraction of f-CNTs/GSs is 3.9 wt%, the limiting oxygen index (LOI) value is increased to 27.4%, and the tensile strength and notched impact strength of epoxy are increased by 33.5% and 44.8%, respectively. Increasing the content of carbon nanomaterials can further improve the flame retardancy and electrical conductivity of EP composites. For the sample containing 11.0 wt% f-CNTs/GSs, the electrical conductivity is further increased to 1.7 x 10(-3) S/cm, which can be regarded as conductive materials. The LOI value is reached to 28.6%, with peak heat release and total heat release reduced by 26.4% and 16.4%, respectively.