Molecular dynamics simulation of CL20/4-bromo-3,5-dinitro-1-methylpyrazole (BMDNP) eutectic-based PBXs

Area of Science:

• Materials Science
• Computational Chemistry
• Energetic Materials

Background:

• CL-20/BMDNP eutectic explosive offers high energy density but suffers from high sensitivity.
• Developing polymer-bonded explosives (PBXs) aims to mitigate sensitivity while retaining performance.
• Investigating polymer binders is crucial for tailoring PBX properties.

Purpose of the Study:

• To computationally predict the impact of five different polymers on CL-20/BMDNP eutectic explosive properties.
• To identify the optimal polymer binder for enhancing stability and reducing sensitivity.
• To evaluate the trade-offs between binder choice, stability, and detonation performance.

Main Methods:

• Molecular dynamics (MD) simulations were employed using Materials Studio software.
• The COMPASS force field was utilized for energetic materials.
• Simulations involved NPT ensemble equilibration at 295 K for 2 ns with a 1 fs timestep.

Main Results:

• The CL-20/BMDNP/PEG model exhibited the highest binding energy and shortest trigger bond length, indicating superior stability, compatibility, and lowest sensitivity.
• The CL-20/BMDNP/F2603 model showed excellent detonation properties but poor compatibility.
• Other polymers like BR, EVA, and PVDF were also evaluated for their effects on PBX properties.

Conclusions:

• Polyethylene glycol (PEG) is identified as the most suitable binder for CL-20/BMDNP-based PBXs due to its ability to enhance integrated properties.
• The CL-20/BMDNP/PEG composite demonstrates improved stability and reduced sensitivity.
• This study provides a computational basis for designing safer and more effective energetic materials.