The Bi‐DOPO derivative functionalized graphene oxide: Preparation and its flame‐retardation on epoxy resin

Abstract

AbstractA novel functionalized graphene oxide (F‐GO) decorated with a double‐phosphaphenanthrene structure was fabricated using a covalent modification method. The F‐GO with Bi‐DOPO groups then was introduced into the epoxy matrix as a highly effective flame retardant. The Flame retardant epoxy resins (FREP) containing F‐GO exhibited superior fire‐resistant performance with extremely low loading. When the content of F‐GO was 1 wt%, the limiting oxygen index value of the FREP was increased from 19.9% to 30.8%, and the total heat release and the peak heat release rate was decreased by 44.0% and 55.5%, respectively. Meanwhile, the tensile and impact tests results indicated that the mechanical properties of the epoxy resins were improved with the addition of F‐GO. Furthermore, the thermogravimetric analysis showed that F‐GO greatly increased the char‐yield of the cured FREP. Based on the char analyses of SEM images, F‐GO was conducive to form a more protective char barrier for FREP during combustion. F‐GO developed a synergistic flame‐retardant effect of the Bi‐DOPO derivative and graphene layer structures on epoxy resins.