The mechanism of the Initial Thermal Decomposition of CL-20 via molecular dynamics simulation

The initial thermal decomposition pathways of supercell structure and signal molecule of CL-20 explosive at various densities and temperatures were studied by molecular dynamics simulations, using Reaxff force field and NPT, NVT ensemble and Berendsen methods. The results show that Two types of N-NO₂ bond in CL-20 molecule can both form NO₂· radical. the initial pathway of CL-20 molecular is only the N-NO₂ dissociation to forming NO₂ radical fragments and R-(NO₂)_n (n≤5), then two NO₂· radical fragments quickly form N₂O₄, N₂O₄ could be broken to form NO and NO₃ or return to two NO₂· radical fragments, the NO₂· radical and other intermediate fragments form the products as N₂ and HNO₃. The initial thermal decomposition pathway of supercell is the same with the initial thermal decomposition pathway of signal molecul, but because of the no bond interacting in the CL-20 solid, the number of NO₂· radical is less than the number of NO₂· radical from CL-20 molecule. HNO₃ molecules, the thermal fragments of CL-20 supercell, can be decomposed to H₂O and N₂O₅.