Equations of state of hexanitrostilbene (HNS)

Abstract

Abstract. Hexanitrostilbene (HNS) is an energetic ingredient that is widely used in commercial and military explosives for its thermal stability. However, characterization of its thermodynamic parameters and phase stability is lacking. Crystalline properties, such as bulk modulus and thermal expansion, are necessary to accurately predict the behavior of shocked solids using hydrodynamic codes. In order to obtain these values, equations of state of fine-particle (type IV) HNS were investigated using synchrotron angle-dispersive x-ray diffraction experiments at static high-pressure and temperature. The samples were compressed and heated using diamond anvil cells. Pressure -volume data for HNS at ambient temperature were fit to the Birch-Murnaghan and Vinet formalisms to obtain bulk modulus and its first pressure derivative. Temperature -volume data at ambient pressure were fit to obtain the volume thermal expansion coefficient.

Pressure dependent Raman spectra used to validate DFT EOS of hexanitrostilbene (HNS)

“…Future calculations will take advantage of newly available exchange correlation functionals, longer MD trajectories, and hydrostatic compression. Our Raman data suggests that the central C=C bond is particularly sensitive to compression, which may corroborate the proposal of Shan et al 1 that breaking of this bond is the initial decomposition pathway.…”

“…To enable simulation of the shock response of materials when shock data is not available, static compression data is sometimes used as a substitute. Gump 1 previously reported xray diffraction data for the isotherm of HNS up to 5 GPa. In this work, we report Raman spectra of fine particle HNS along the 300 K isotherm at pressures up to 6 GPa.…”

Unreacted equation of states of typical energetic materials under static compression: A review

“…Experimentally, Gump et al determined the EOS of HNS at room temperature in the pressure range of 0-5.4 GPa using angle-dispersive XRD. [56,57] The results show that the a and b axes are more compressible than the c axis and it is also a reversible compression process similar to that of LLM-105. [47] The calculated B 0 and B are 11.2±0.66 GPa and 6.2±0.69, respectively, using the 3 rd BM EOS at ambient condition.…”

Modeling compressive reaction and estimating model uncertainty in shock loaded porous samples of hexanitrostilbene (HNS)

“…The Naval Surface Warhead Center, Indian Head Division, has had a long tradition of providing isothermal compression data using the Diamond Anvil Cell (DAC). Details of the experiments are presented in a complementary paper by the co-author, J. Gump, and his colleagues in the current SCCM proceedings [13]. They reported an isothermal bulk modulus and isothermal bulk modulus pressure derivative as 66 .…”