Construction of layer-by-layer coating based on graphene oxide/β-FeOOH nanorods and its synergistic effect on improving flame retardancy of flexible polyurethane foam

The binary hybrid-filled layer by layer coating, composed of graphene oxide and beta-FeOOH nanorods, was fabricated onto flexible polyurethane (FPU) foams by layer by layer assembly technique to reduce its flammability. Scanning electron microscopy images showed that the coexistence phenomenon between GO nanosheets with beta-FeOOH nanorods can be found to cover on the FPU foam surface. The analysis by thermogravimetric analysis/infrared spectrometry (TGA-IR) indicated that the binary-hybrid filled coating has greater advantages in suppression of gaseous product generation, meaning that less "fuel" was fed back to'the flame. Compared with the single component (graphene oxide or beta-FeOOH nanorods)filled coatings, the binary hybrid-filled coating has greater reduction (49.5%) in peak heat release rate (PHRR) and could almost eliminate the second PHRR for FPU foams in the cone test, which indicates its superiority. As a result, the complementary effect between graphene oxide nanosheets with beta-FeOOH nanorods enhanced the flame retardant effect for FPU foams. (C) 2016 Elsevier Ltd. All rights reserved.