PA-6 clay nanocomposite hybrid as char forming agent in intumescent formulations

This work deals with new flame retardant (FR) intumescent formulations for ethylene-vinyl acetate copolymers (EVA) using charring polymers polyamide-6 (PA-6) and polyamide-6 clay nanocomposite hybrid (PA-6-nano) as carbonization agents, Use of PA-6 nano improved both the mechanical and fire properties of FR EVA-based materials, The part played by the clay in the improvement of the FR performance was studied using FTIR and solid state NMR, It is shown that the clay allowed the thermal stabilization of a phosphorocarbonaceous structure in the intumescent char which increased the efficiency of the shield and, in addition, the formation of a 'ceramic' which can act as a protective barrier. Copyright (C) 2000 John Wiley & Sons, Ltd.