▎ 摘　　要

In this study, the synergistic effect of carbon nanotubes (CNTs) and graphene oxide (GO) on the flame retardant properties of waterborne intumescent epoxy coatings was investigated. Firstly, bio-inspired polydopamine (PDA) was wrapped on the surface of CNTs to increase their water dispersibility and provide them with abundant reactive functional groups. Then, the 3-Aminopropyl triethoxysilane (KH550) was grafted on CNTs/PDA surface. Subsequently, the GO was combined with the modified CNTs by chemical reaction to obtain the GO@M-CNTs hybrids. The results showed that the composite coating with GO@M-CNTs hybrids had better fire retardant performance than the addition of CNTs or GO nanosheets alone. In contrast, the composite coating loaded with 1.5% of GO@M-CNTs hybrids exhibited the lowest backside temperature (168.2 degrees C), indicating its highest thermal insulation performance. Moreover, the results of the furnace storage experiments displayed that the GO@M-CNTs1.5%/EP sample exhibited the maximum expansion height (13.7 mm) and expansion rate (10.79) due to the hybrids effectively hindering the escape of the foamed gas into the air. In addition, the GO@MCNTs1.5%/EP composite coating exhibited the maximum Tmax (370.4 degrees C) and char residue (28.8%) during the TGA test, which resulted in its most excellent fire retardant performance.