MoS2-filled coating on flexible polyurethane foam via layer-by-layer assembly technique: flame-retardant and smoke suppression properties

In the present work, a fire-blocking coating consisting of chitosan and molybdenum disulfide (MoS2) was firstly deposited onto flexible polyurethane (FPU) foam by the layer-by-layer assembly technique. With the MoS2-filled coating, the FPU foam could burn without melt dripping during the whole combustion and keep its shape after combustion, while the pure foam was consumed completely. The analysis by thermogravimetric analysis/infrared spectrometry indicated that MoS2-filled coating could obviously reduce the amount of organic gaseous pyrolysis products and toxic volatiles during thermal decomposition of the foam. The cone calorimeter results indicated that the FPU foam with 8.5 wt% coating showed great reduction in peak of heat release rate (70%), peak smoke production rate (62.4%) and total smoke released (33.3%). Such a significant improvement in flame-retardant and the smoke suppression properties for FPU foam could be attributed to the protective effect of MoS2-filled coating.