High‐Pressure Characterization of Melt‐Castable Energetic Materials: Bis(Nitroxymethylisoxazolyl) Furoxan (DNDIF)

Abstract

The high-pressure behavior of bis (nitroxymethylisoxazolyl) furoxan (DNDIF) was studied at ambient temperature and pressures approaching 30 GPa by Raman spectroscopy and powder X-ray diffraction. There was no evidence of a phase change observed over this pressure range, indicating that the ambient structure of DNDIF remains stable up to conditions similar to the detonation pressure of the material. Such findings suggest that this melt-castable explosive may be used in the replace-ment of 2,4,6-trinitrotoluene (TNT) in energetic formulations without the concern of uncontrolled polymorphism that might otherwise affect the performance and safety of the munition. Additionally, empirical understanding of the effect of different structural motifs in the crystal packing builds on understanding of what macroscale features are desirable for future materials and gets us closer to the design of future novel energetics.

High‐Pressure Characterization of Two Stereoisomers of Tetranitroester Cyclobutane

“…From the analysis of the P−V data, the following values for the bulk modulus ( B 0 ) and pressure derivative of ( B’ ) were derived: [cis‐trans‐cis] – B 0 =15.50±1.02 GPa and B’ =5.63±0.67, [all‐cis] – B 0 =11.65±0.26 GPa and B’ =6.22±0.18. These bulk modulus values are consistent with similar cyclic energetic molecules: BIDN (16.1±0.5/7.2), LLM‐105 (15±4/9±3), LLM‐172 (18.5±1.4/8.1), and DNDIF (14.9±0.9/6.7±0.6), respectively, for B 0 and B’ [7e, 8b–d]. The total volume compression upon increasing the pressure from ambient conditions to near 25.0 GPa was observed to be 32.9 % for [cis‐trans‐cis] and 38.9 % for [all‐cis].…”

“…The average peak shift value was 3.4 and 3.5 cm −1 GPa −1 for [cis‐trans‐cis] and [all‐cis], with ranges between 0.5 to 8.3 and 0.4 to 14.1 cm −1 GPa −1 , respectively for the two materials. These peak shift values are within the expected range for soft organic materials with applied pressure [7d, e, 8d, 13]. The largest frequency shift in [cis‐trans‐cis] (8.3 cm −1 GPa −1 ) and [all‐cis] (14.1 cm −1 GPa −1 ) occurs for the symmetric/asymmetric stretching of the C−H groups around 3050 cm −1 and may indicate a deformation of the methyl linkages.…”

“…Coupling Raman spectroscopy and powder X‐ray diffraction (PXRD) with the DACs allows for probing of the phase behavior at high‐pressure, where polymorphs of higher sensitivity may ultimately derail a material's development. This technology had been applied to many traditional energetic materials, as well as novel energetics, and yielded information on previously unknown high‐pressure phases [7a, d, e, 8]. Analysis of the pressure vs lattice data derived from indexing of the PXRD data allows for the equation of state (EOS) to be determined, which ultimately provided information on the compressibility of a material [isothermal bulk modulus ( B 0 ) and its pressure derivative ( B ’ )].…”

High Pressure Study of Pharmaceutical and Energetic Material Hexamethylenetetramine

“…As an omnipresent intermolecular interaction, hydrogen bonds can undergo profound alterations under the influence of external pressure. Over the past few decades, extensive efforts have been dedicated to probing the high-pressure structures of hydrogen-bonded pharmaceutical and energetic materials. − The transition from phase III to phase I of piracetam has been examined under experimental conditions involving compression of phase III to 0.2 GPa at 443 K . Additionally, the compression of phase II of piracetam within pressure ranges of 0.45–0.70 GPa induced a reversible, single-crystal to single-crystal transition, resulting in a novel polymorph, phase V .…”

High‐Performance and Insensitive DNTF‐DFTNAN Eutectic: Binary Phase Diagram and Characterization

“…Melt-cast explosives are widely used on account of simple process, high efficiency and low cost [1][2][3][4]. However, the traditional TNT (2, 4, 6-trinitrotoluene)-based explosives are difficult to satisfy the requirements of modern ammunitions because of its low energy, poor environmental adaptability and toxic issue [5][6][7].…”