Pyrolysis characteristics, reaction mechanisms and gas emission of organic fireproof plugging materials by TG-FTIR-MS

Organic fireproof plugging material (OFPM) is commonly applied in buildings to prevent the spread of smoke and flame. Its pyrolysis characteristics, reaction mechanisms and gas emission were studied by thermogravimetric analysis coupled with Fourier infrared spectroscopy and mass spectrometry (TG-FTIR-MS). The thermogravimetric analysis showed that the pyrolysis process of OFPM in nitrogen might be divided into four stages, which could be attributed to the dehydrogenation of polychloroprene (PCP), depolymerization of PCP and decomposition of kaolinite and carbonate. The reaction mechanism of OFPM in nitrogen atmosphere was further investigated by various kinetic methods. The average activation energy of the four stages was 92.47, 166.47, 239.69 and 232.72 kJ mol −1 . In addition, ( g(a) = [1−(1– a ) −3 ]/ (−3)) was responsible for Stage I, and ( g(a) = [−ln(1– a )] 2 ) was responsible for Stage IV. The characteristic parameters and kinetic triplets were verified by predicting the experimental data at an extra heating rate. The predicted conversion rate curve was consistent with the experimental conversion rate curve, which manifested the accuracy of the obtained parameters. In addition, the evolved gas consisted of ethane, HCl, 1, 3-butadiene, 2-chloro-1, 3-butadiene and CO 2 by the FTIR-MS analysis. Eventually, the pyrolysis pathway was proposed based upon thermogravimetric and gas analysis results.