Modeling of the thermal decomposition of a treated plywood from thermo-gravimetry and Fourier-transformed infrared spectroscopy experimental analysis

The modeling of the inflammation, the spread of a fire and its extinguishment represent today a significant challenge. In order to reliably predict the behavior of such a fire, an adequate description of the thermal decomposition is necessary. Cellulosic materials are of primary importance because of their increasingly use in buildings and furniture. The purpose of this study is to propose a more accurate model for pyrolysis of solid fuel over existing ones by addressing the thermal degradation of a fire retardant treated plywood (classification B in the Euroclass). The joined use of thermogravimetric analyzer in non-isothermal conditions to Fourier transformed infrared spectroscopy is applied to investigate experimentally the thermal degradation of the plywood. The experiments have been conducted under inert (nitrogen) and oxidative (air) atmospheres at different heating rates, from 5 to 50 C min -1. Characterizations of volatile degradation products as well as the temporal evolution of the sample weight and mass loss rate provide the information needed to propose a kinetic mechanism of thermal degradation. The kinetic parameters of each reaction involved in this thermal degradation mechanism being unknown there have been determined using the genetic algorithms approach. A very good agreement is then obtained between the numerical and the experimental results of MLR, permitting the validation of the pyrolysis model developed at this scale