The influences of graphene and carbon nanotubes on properties of waterborne intumescent fire resistive coating

Mixed carbon materials composed of carbon nanotubes and graphene were applied as fire retardant filler in the fire resistive coating. The fire resistance, thermal stability, water resistance and mechanical properties were investigated respectively. Scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) were used to study the morphology and composition of the carbon chars. The results indicated that the combination of graphene and carbon nanotubes could have a synergistic effect on fire protection and thermal stability. Additionally, when the weight ratio of graphene and carbon nanotubes was 3:1, the coating exhibited “Excellent” fire resistance and flame retardancy index (FRI) was over 10. SEM, EDS, XRD analysis demonstrated that the carbon content of dense carbon layer achieved 40.97% and titanium pyrophosphate was generated. The coating with higher content of graphene exhibited better water resistance, mechanical properties and adhesion level.