Fire Safety Science Digital Archive

Ignition behavior of selected polymers, commonly used in the automotive industry, has been characterized by the maximum heat flux at which there is no ignition, defined as the Critical Heat Flux, CHF, and by a combination of thermo-physical properties, defined as the Thermal Response Parameter (TRP). Polymers with high CHF and TRP values have high resistance to ignition. The ignition temperatures of the polymers appear to be about 10 % higher than their decomposition temperatures. The TRP values calculated from the thermo-physical properties of the polymers (ignition temperature, density, heat capacity, and thermal conductivity) are about 33 % lower than the experimental TRP values obtained from the measured time-to ignition at various external heat flux values. Inclusion of bond energies and chemical nature of vapors in the TRP formulation is suggested. The CHF and TRP values of the selected polymers are comparable to the values for ordinary combustible materials, but are lower than the values for the highly thermally stable specialty polymers.