Ignition mechanisms in polymers and polymer nanocomposites

This paper addresses the behavior of thermoplastic polymers and polymer nanocomposites prior to ignition, under irradiation in a cone calorimeter. Insights into the physical evolution of material controlling ignition are obtained from the measurement of the condensed phase surface temperature and by the observation of specimen residues obtained from interrupted tests. Significant differences are evidenced between evolution of montmorillonite nanocomposites and reference polymers, in terms of both reduced ignition time and reduced thickness of material contributing to fuel production at ignition, whereas limited differences in the temperature of the surface layer at ignition were measured. An explanation for the reduction of ignition time by the presence of nanoclays, based on nanoparticle-catalyzed oxidation, is proposed and discussed. Copyright (C) 2011 John Wiley & Sons, Ltd.