Thermal Decomposition Mechanism and Fire-Extinguishing Performance of trans-1,1,1,4,4,4-Hexafluoro-2-butene: A Potential Candidate for Halon Substitutes

Abstract

In view of the appropriate physicochemical characteristics and environmental friendliness of the trans-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz­(E)) substance, the thermal-decomposition mechanism as well as the fire-extinguishing mechanism and performance of this agent were systematically studied by employing both experimental and theoretical methods in this work. We found that the HFO-1336mzz­(E) agent not only has promising thermal stability at room temperature but also exhibits pronounced fire-extinguishing performance, which is comparable to that of HFC-236fa and even better than that of HFC-125 extinguishant. Additionally, the promising fire-extinguishing performance of HFO-1336mzz­(E) may result from the physical and chemical extinguishing effect of its thermal-decomposition products including HFO-1336mzz­(Z), HCCCF3, CF3CCCF3, and CF3H, which makes a significant contribution to capturing the free radicals in the flame, as well as cooling and diluting the combustible fuel-air mixture. Both experimental and theoretical results suggest that the HFO-1336mzz­(E) agent is a highly recommendable candidate for Halon extinguishant, which is worthy of further investigation and evaluation of its practical applicability in fire-suppression utilization.

Thermal decomposition and fire‐extinguishing mechanism of N(CF2CF3)3 by ReaxFF‐based molecular dynamics simulation and density functional theory calculation

“…Notably, the formed CF 3 ∙ radical can spontaneously combine with H∙ radicals without hindrance, leading to the reformation of CF 3 H, and its energy is obviously lower than that of reactants. Meanwhile, the hydrogen atom in CF 3 H molecules can be removed by hydroxyl and hydrogen radicals to produce CF 3 ∙ radicals, and the corresponding energy barriers are 1.10 and 8.13 kcal mol −1 , respectively, which can be ignored [33]. Therefore, OH∙ and H∙ radicals will be consumed in the cyclic reaction, and the supply of CF 3 ∙ radicals in the fire‐extinguishing process at high temperatures seems inexhaustible.…”

Thermal decomposition and fire‐extinguishing mechanism of CF3I: A combined theoretical and experimental study

“…In high‐temperature conditions, CF 3 I would degrade into some products that may react with OH· and H· radicals in the burning flame and thus restrain the chain reaction of combustion to a certain degree. According to our previous research on HFO‐1336mzz(E) [28], the residence time of 10 s is selected for thermal decomposition analysis of CF 3 I. Since the bonding length of CI bond in CF 3 I is relatively long and easy to break [29], the experimental temperature was started from 200°C to explore the initial decomposition temperature, at which the thermal decomposition of CF 3 I actually begins.…”

Thermal decomposition and fire extinguishing mechanism of CF3I: a combined theoretical and experimental study

“…According to the thermal decomposition study of HFO-1336mzz(E) by Zhang 16 , considering the convergence of decomposition rate at 10s and the short time of fire extinguish process, the residence time of 10s is selected for thermal decomposition analysis. Considering the low molecular weight of CF 3 I, its decomposition into organic products is difficult, and the decomposition temperature should be relatively high.…”