Abstract:

A molecular dynamics simulation study on the thermal decomposition mechanism of perfluorohexanone using the tight functional model based on density functional model (DFTB) and the improved reaction force field (ReaxFF) was condcted. The initial reaction path of thermal decomposition,the microscopic reaction process and the gas generation mechanism in the system was analyzed. The effect of temperature on the thermal decomposition of perfluorohexanone was discussed.The first-order kinetic equation based on simulation data was established and the first-order kinetic evaluation of the thermal decomposition process was carried out. The results showed that the initial reaction of thermal decomposition of perfluorohexanone is: perfluorohexanone → perfluoroisopentane + carbon monoxide. The main products of thermal decomposition of perfluorohexanone are carbon monoxide, tetrafluoromethane, hexafluoropropylene,perfluoroisobutylene, decafluorobutane, perfluoroisopentane and a large number of active groups. The firstorder kinetic evaluation showed that the pre- finger factor and the apparent activation energy were 5.0217×1014 s-1 and 1 771.96 kJ/mol, respectively.

Key words:

perfluorohexanone; ReaxFF, DFTB, thermal decomposition mechanism