Time-resolved Raman spectroscopy study of rapid compressed β-HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)...

We present time-resolved Raman spectroscopy measurements to study the structural response of β-HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) up to 20 GPa and over compression rates ranging from 0.03 to 1.07 GPa/s using a dynamic diamond anvil cell. Similar to previous static high pressure results, two phase transitions of β→ζ and ζ→ɛ were observed at approximately 5.7 and 9.5 GPa, respectively, regardless of the compression rate. This can be attributed to the fast transition kinetics of a displacive transition mechanism. Further, when decompressed to ambient pressure, all the phase transitions are reversible and there is no chemical reaction. Our results clearly indicate that little effect of the investigated compression rates on the structural response of β-HMX, suggesting the behavior of β-HMX during manufacture, transport or handling can be molded using the existing static high pressure data, which will contribute to the prediction of the safety of β-HMX based explosives and development of kinetic initiation models.