Pyrolysis mechanism of tetrahydrotricyclopentadiene by ReaxFF reactive molecular dynamics simulations

Tetrahydrotricyclopentadiene (THTCPD) has high density and volumetric heat, but its viscosity is also high, resisting its ignition and combustion, which somewhat limits its applications. Therefore, it is crucial to understand the mechanism of THTCPD pyrolysis. In this study, the ReaxFF reactive molecular dynamics simulations were performed to investigate the thermal dissociation of THTCPD. The detailed description of THTCPD pyrolysis behavior was obtained from the aspects of initial reactions, main species distributions and intermolecular reactions. Initiation of the THTCPD decomposition is mainly through C-C bond fission of the bicycloheptyl structure in the middle, leading to the formation of highly active C15H22 diradicals. To give a better description of the pyrolysis behavior, main products related intermolecular reactions should be considered in the mechanism. The simulated pre-exponential factor A (2.30 x 1015 s-1) and activation energy E (55.72 kcal/mol) captured from simulations are found to be reasonably consistent with the experimental values.