Graphite oxides as effective fire retardants of epoxy resin

Graphite oxides (GOs) at various oxidation states were examined as fire retardants of epoxy resin. Excessive oxidation is detrimental to the fire retardant effect of GO because it generated a weak GO with reduced intumescent ability. GO manifested optimum fire retardant properties when it was properly oxidized due to the effective intumescence, demonstrating that intumescent GO needs to be strong enough to effectively push the epoxy resin matrix apart to cause efficient intumescence and generate a solid remnant char that acts as an efficient barrier. The fire retardant effect of GO was also reduced when a dispersion of GO in the epoxy resin was enhanced by sonication. This shows that the fine dispersion and disordering of layered structure of GO by the intercalation of epoxy molecules into the gallery of GO also reduced the intumescent ability, and the fire retardant effects of GO.