A Molecular Dynamics Study of Chemical Reactions of Solid Pentaerythritol Tetranitrate at Extreme Conditions

A Molecular Dynamics Study of Chemical Reactions of Solid Pentaerythritol Tetranitrate at Extreme Conditions PDF Author: C. J. Wu
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

Get Book Here

Book Description
We have carried out density functional based tight binding (DFTB) molecular dynamics (MD) simulation to study energetic reactions of solid Pentaerythritol Tetranitrate (PETN) at conditions approximating the Chapman-Jouguet (CJ) detonation state. We found that the initial decomposition of PETN molecular solid is characterized by uni-molecular dissociation of the NO{sub 2}groups. Interestingly, energy release from this powerful high explosive was found to proceed in several stages. The large portion of early stage energy release was found to be associated with the formation of H{sub 2}O molecules within a few picoseconds of reaction. It took nearly four times as long for majority of CO{sub 2} products to form, accompanied by a slow oscillatory conversion between CO and CO{sub 2}. The production of N{sub 2} starts after NO{sub 2} loses its oxygen atoms to hydrogen or carbon atoms to form H{sub 2}O or CO. We identified many intermediate species that emerge and contribute to reaction kinetics, and compared our simulation with a thermo-chemical equilibrium calculation. In addition, a detailed chemical kinetics of formation of H{sub 2}O, CO, and CO{sub 2} were developed. Rate constants of formations of H{sub 2}O, CO{sub 2} and N{sub 2} were reported.