Pyrolytic characteristics, kinetics, thermodynamics, volatile products and chemical reactions of micron polypropylene infiltrated with kerosene

Abstract

The pyrolysis of polymers infiltrated with combustible liquids is one common behavior in the fire accidents resulted by the leakage and overflow of combustible liquids over polymers. The present study may provide a theoretical basis and guidance for the prediction of fire development, the selection or design of fire detection and the design of ventilation and fire extinguishing systems. In the present study, the thermal decomposition behaviors, kinetics, thermodynamics, volatiles and chemical reactions of micron polypropylene (typical polymer) infiltrated with kerosene (typical combustible liquid) are investigated. It is concluded that the thermal decomposition process of micron PP with kerosene can be divided into two stages, and all stages can be considered as one-step reaction. As the kerosene content increases, the average and peak reaction rates of the first stage increase, while they decrease for the second stage and the whole process. As the heating rate increases, the average and peak reaction rates of the whole process decrease. In addition, increasing the heating rate or kerosene content may result in better combustion performance compared with that of pure PP. The calculated average activation energy, pre-exponential factor and global reaction model of the second stage can well predict the thermal decomposition behaviors of this stage. Thermodynamic analysis shows that the thermal decomposition of micron PP with kerosene is an endothermic and non-spontaneous reaction. The main volatile products contain olefins, alkynes, alkanes, hydrogen, carbon dioxide, carbon monoxide and aromatic compounds. The possible chemical reactions generating the above-mentioned products are deduced.