The Reaction Pathway Analysis of 2-Bromo-3,3,3-trifluoropropene with the Active Radicals and Pyrolysis of 2-Bromo-3,3,3-trifluoropropene

摘要

As a new kind of Halon replacement, 2-bromo-3,3,3-trifluoropropene (2-BTP) has been paid broad attention due to its superior fire suppression performance and properties. Although the fire suppression performance and extinguishing mechanism of 2-BTP have been widely reported so far, there is few theoretical and experimental research about the reaction mechanism of 2-BTP with the active radicals and pyrolysis of 2-BTP. In this study, 2-BTP was pyrolyzed with a flow of nitrogen carrier gas in a tubular pyrolysis reactor over the temperature range of 25-800 °C. Its decomposition products were analyzed by GC and GC-MS. The major decomposition products were verified to be CF3CCH and CF3Br. It can be speculated that only when flame temperature was above 600 °C, decomposition products were generated rapidly by pyrolysis of 2-BTP and reacted with reactive radicals to stop the combustion reaction. Based on the above experiment results, Gaussian 03 was applied to calculate the possible pathways of fire-extinguishing using the Density function theory (DFT) method with the 6-311++G(d, p) basis set. There are five possible pathways in the reaction of 2-BTP with OH radical and three possible pathways of 2-BTP pyrolysis. Combining the experimental results and theoretical calculations, the fire-extinguishing mechanism of 2-BTP was proposed.