Influence of the composition of PMMA nanocomposites on gaseous effluents emitted during combustion

This paper focuses on the nature of thermal degradation products formed by combustion of various PMMA nanocomposites and on the kinetics of emission of gases emitted during combustion. Compositions of two kinds of nanosilica and nanoalumina and their combinations with Ammonium PolyPhosphate (APP) in PMMA were prepared. Their thermal degradation was carried out using TGA coupled with FTIR and cone calorimeter. For the compositions of nanooxides, it appears that the kinetics of emission of gases is significantly influenced by the nature of oxide and by the surface treatment, but mainly for silica. Octylsilane modified silica combined with APP leads to an outstanding fire behaviour, due to the formation of a very cohesive and expanded layer containing silicon pyrophosphate, but at the expense of a higher CO emission and a measurable emission of HCN. Even if the presence of fire retardant (APP) and the incorporation of nanosilica with a surface treatment reduce the flammability, the high value of the CO yield could lead to the conclusion that the combination could improve toxicity. But, the nanocomposite based on silica surface treatment coupled with APP, induce a delay of the CO yield emission, which could allow people to evacuate buildings or houses in case of fire.