An investigation of flammability properties to kinetics of polyamide 11 nanocomposites

Several classes of polymer nanocomposites such as polyamide 11-clay, polyamide 11-carbon nanofibers, polyamide 11-multiwall carbon nanotubes, polyamide 11-clay-intumescent, polyamide 11-carbon nanofiber intumescent nanocomposites were developed by our research group. Our long term research objective is to develop a family of PA11 nanocomposites (PA11Ns) with enhanced flammability and mechanical properties. The rate of thermal decomposition of polymers can be modeled by the kinetic rate equation, with parameters A, the pre-exponential factor, E, the activation energy, and n, the order of reaction. In the literature, there are several methods to determine the kinetic parameters from experimental data. One of the most widely used methods is multiple heating rate technique, proposed by Friedman in 1965, through the use of thermogravimetric analysis (TGA). The isoconversion method was used to calculate the activation energies (Es), since the mechanisms of polymer thermal degradation are often unknown and too complicated to be characterized by a simple kinetic model. Flammability properties of PA11Ns were characterized using the UL 94 test method. This paper will attempt to develop a correlation between these two methods in order to better understand the thermal behavior of this family of PA11Ns.