Interactions between Nanoclays and Flame Retardant Additives in Polyamide 6 and Polyamide 6.6 Films

levels of flame retardancy, especially in thin films, and fibres where the development of surface silicaceous coatings is less probable, the addition of conventional char-promoting flame retardants provides the means of increasing ignition resistance. Films of polyamide 6, and 6.6, with, and without commercial nanoclay were cast, and flammability studies using limiting oxygen index undertaken. A range of additives including ammonium polyphosphate, melamine phosphate, cyclic phosphonate species, and other phosphorus-containing species suggest that synergistic, additive, and antagonistic effects are observed depending on the flame retardantnanoclay combination chosen. The results are explained in terms of a simple model based on the nanoclay functioning as a char-bridging species between dispersed flame retardant centres within the polymer matrix