FTIR–PCFC coupling: A new method for studying the combustion of polymers

Gases released from pyrolysis and partial combustion of various polymers (low-density polyethylene, polystyrene, poly(parabromostyrene), pure and flame-retarded polypolyamide 6, cellulose, and chloroprene) were studied using a new coupling between Fourier transform infrared spectrometry (FTIR) and pyrolysis combustion flow calorimetry (PCFC). Combustion in PCFC was monitored by modifying the combustion temperature between 600 and 900 °C. Decreasing the combustion temperature in PCFC leads to partial combustion and the evolution of CO, but also of methane, acetylene, or ethylene when temperature is very low. The evolution of these gases depends also on the polymer and on the presence of a flame inhibitor, demonstrating that flame inhibition can be studied using this method. A correlation between FTIR–PCFC and FTIR–cone calorimetry coupling was attempted via the CO/CO2 ratio. The first results show that an “isoconversion temperature” in the cone calorimeter test may be estimated. Polar gases such as chlorinated or brominated gases are not fully observed using this method due to possible adsorption in the transfer line before they reach the FTIR gas cell.