Introducing Nitramide Group into High Energy Density Material Molecule Leads to Enhanced Performance

Area of Science:

• Computational chemistry and materials science.
• Focus on high energy density materials (HEDMs) and energetic explosophores.

Background:

• Nitrogen-rich groups are known to enhance detonation properties of HEDMs.
• The precise influence of energetic explosophores on energy storage and release in HEDMs remains unclear.
• BCHMX molecule was designed based on HMX, introducing intramolecular carbon-carbon linkages for functionalization.

Purpose of the Study:

• To design and investigate the properties of a novel HEDM, BCHMX-ENO, by introducing a nitramide group.
• To understand the atomic-level influence of the nitramide group on the energetic properties and thermal decomposition of HEDMs.
• To evaluate the detonation performance and environmental impact of BCHMX-ENO compared to BCHMX.

Main Methods:

• Crystal structure prediction using evolutionary algorithms (USPEX).
• Quantum mechanics molecular dynamics (QM-MD) for initial thermal decomposition analysis.
• Reactive molecular dynamics (RxMD) with ReaxFF force field combined with QM-MD for detonation performance prediction.

Main Results:

• The nitramide group affects initial reaction steps by altering molecular spatial distribution, bond length, and atom distance.
• BCHMX-ENO exhibits improved detonation properties: 7.40% higher Chapman-Jouguet (CJ) pressure, 2.54% higher detonation velocity, and 6.60% higher CJ temperature than BCHMX.
• The enhanced performance is attributed to increased nitrogen content and oxygen balance, leading to more N2 and CO2, and fewer carbon clusters.

Conclusions:

• The introduction of the nitramide group significantly enhances the detonation performance of HEDMs.
• BCHMX-ENO demonstrates superior energetic properties and a more favorable decomposition product profile (less CO) compared to BCHMX.
• This study provides atomic-level insights into functional group influence on HEDM properties, guiding the design of greener, high-performance energetic materials.