Effect of a graphene-APP composite aerogel coating on the polyester fabric for outstanding flammability

Catalytic charring is an important way to realize flame retardant modification of polymer, especially for carbonaceous polymers. In this paper, graphene aerogel (GA) as a new carbon carrier, and ammonium poly-phosphate (APP) as catalyst, an efficient integrated composite aerogel (GA-APP) is constructed and in situ grown on the surface of polyester fabric by the hydrothermal reduction method. The flame retardancy and mechanism of GA-APP has been investigated in detail by limiting oxygen index (LOI), x-ray photoelectron spectroscopy (XPS), thermogravimetry-infrared (TG-IR) and cone calorimeter (CONE) method. The results showed that, with the addition of 26 % GA-APP powder, the LOI value of GA-APP/PET fabric is 34.1 %, and the vertical combustion test passed B1 grade. GA-APP flame retardant significantly reduced the peak heat release rate, total heat release, total smoke production and smoke rate of PET fabric through the synergistic effect of GA and APP. The char residual amount of GA-APP/PET fabric increased to 91.5 % after the combustion during the CONE test. GA-APP mainly played the role of agglomerative flame retardant by changing the char structure and char quantity, which can function the stronger barrier effect and inhibit the combustion reaction. The dense and carbon layer with high thermal stability formed under the synergistic action of GA-APP. This layer can isolate heat transfer, flame retardant and smoke suppression during PET fabric combustion.