A reactive molecular dynamics study of the pyrolysis mechanism of C6F12O

Abstract

C6F12O (perfluoro-2-methyl-3-pentanone) is a high-potential environmentally friendly substitute agent applied in fire protection, the power industry and refrigeration. Herein, a series of reactive force field molecular dynamics (ReaxFF MD) simulations is performed to investigate C6F12O pyrolysis. Six initial pyrolysis reaction pathways are determined mainly through fission of the C–C bond of C6F12O. The terminal C–C bond dissociation forming the CF3 radical occurs prior to that of those at the other positions. High-energy C–F and C=O bonds are broken at high temperatures and CF3 and F radical chain reactions. CF4, C2F2 and COF2 are the main pyrolysis products, while other products including C2F6, C3F8, F2 and C2OF6 are also observed in the simulations. The environmental impacts, toxicity and corrosiveness of these products need to be further evaluated. The whole C6F12O pyrolysis process is endothermic except for certain bonding reactions. COF2 is largely generated through a combination of the F and COF radicals and COF3 defluorination. First-order kinetic analysis of C6F12O pyrolysis is also performed and the pre-exponential factor and apparent activation energy of C6F12O are calculated.