Reaction mechanism and kinetics properties of β-HMX under different thermodynamics States: A theoretical study for thermal decomposition

The thermolysis of beta-HMX under different thermodynamics states are investigated using quantum-based molecular dynamics method. The reaction is mainly initiated with molecular ring breaking and alkyl dehydrogenation. The cleavages of N-N and C-N bonds are impeded under high pressure, while that of C-H bond is significantly enhanced. NO3 is more favorably produced under low pressure, which can promote the hydrogen transfer to form H2O or OH. The reaction kinetics constants reflect that the initial endothermic reaction is really slower under high pressure, but the following exothermic reaction is significantly accelerated with a larger reaction heat of 368.05 cal.g(-1).

Automated summary

The thermolysis of beta-HMX under different thermodynamics states has been investigated using quantum-based molecular dynamics method. The reaction is mainly initiated by molecular ring breaking and alkyl dehydrogenation. The cleavage of N-N and C-N bonds is hindered under high pressure, while the cleavage of C-H bond is significantly enhanced. NO3 is more favorably produced under low pressure, promoting hydrogen transfer to form H2O or OH. The reaction kinetics constants reflect that the initial endothermic reaction is slower under high pressure, but the subsequent exothermic reaction is significantly accelerated with a larger reaction heat of 368.05 cal.g(-1).