Preparation and Properties of Ultra-fine HNS-IV

Abstract

Ultra-fine 2,2’,4,4’,6,6’- Hexanitrostilbene (HNS-IV) was obtained by HNS-II by vibration cavity comminute. This method uses only alcohol and deionized water, which can be viewed as a green technology. The morphology, particle size, specific surface area, thermal decomposition property and the threshold energy for slapper detonator were compared between HNS-IV and HNS-II in this paper. Results show that after HNS pulverizing, the particle size decreased from 27.18μm to 1.44μm, the specific surface area increased from 0.73m2•g−1 to 9.10m2•g−1. DSC analysis shows that the decomposition peak temperature Td decreases and the melting temperature Tm increases after pulverizing. It is speculated that in the explosive reaction with very high heating rate, the enthalpy of decomposition will be increased by pulverizing, which will be more conducive to detonation growth and explosive reaction. According to the calculation of thermal decomposition kinetics, the decomposition and activation energy Ea of HNS decreases after pulverizing, and the thermal decomposition reaction rate of HNS-IV increases when the temperature is less than 409.6°C. The initiation threshold test of the impact plate shows that the 50% initiation threshold energy of HNS- II is 1.242J, and the 50% initiation threshold energy of HNS-IV is 0.558J, and the initiation threshold for slapper detonatorer is significantly reduced by 55%. This means that the ultra-fine HNS-IV is very suitable as the main ingredient in the booster in the EFI initiation.