Synergistic effect of carbon nanotubes on the flame retardancy of poly(methyl methacrylate)/zinc oxalate nanocomposites

Abstract

Carbon nanotubes have incorporated in poly(methyl methacrylate) (PMMA) nanocomposites as a synergist of zinc oxalate nanoparticles in order to enhance the flame retardancy. PMMA nanocomposites filled with the newly developed environmentally friendly zinc oxalate nanoparticles and with multi-walled nanotubes (MWNTs), both serving as flame retardants, were prepared by applying the solution blending method. The fire behavior of these composites was systematically studied by carrying out limiting oxygen index (LOI) and pyrolysis combustion flow calorimetry (PCFC) tests. The introduction of MWNTs into the PMMA/zinc oxalate nanocomposites improved the LOI values and markedly decreased the peak heat release rate. It can be suggested that this improvement in the flame retardancy resulted from the formation of stable protective char layers during the combustion process