Molecular dynamics simulation of CL20/DNDAP cocrystal-based PBXs

Area of Science:

• Materials Science
• Computational Chemistry
• Energetic Materials

Background:

• CL-20/DNDAP cocrystal exhibits high energy density but also high sensitivity compared to traditional insensitive explosives.
• Reducing the sensitivity of CL-20/DNDAP cocrystal is crucial for developing safer and more practical energetic materials.
• Polymer binders are essential for creating polymer-bonded explosives (PBXs) with improved safety and mechanical properties.

Purpose of the Study:

• To investigate the effects of six different polymer binders on the stability, sensitivity, and detonation performance of CL-20/DNDAP cocrystal-based PBXs.
• To identify the most suitable polymer binder for enhancing the comprehensive properties of CL-20/DNDAP cocrystal explosives.

Main Methods:

• Established a CL-20/DNDAP cocrystal model and incorporated six polymers (BR, EVA, PEG, HTPB, F2603, PVDF) onto its cleaved surfaces.
• Utilized molecular dynamics (MD) simulations with the COMPASS force field at 295K and a 2ns simulation time.
• Analyzed binding energy, trigger bond length, mechanical properties, and detonation performance to predict binder effects.

Main Results:

• The CL-20/DNDAP/PEG model showed the highest binding energy and lowest trigger bond length, indicating superior stability, compatibility, and reduced sensitivity.
• The CL-20/DNDAP/F2603 model exhibited strong detonation capabilities but poor compatibility.
• PEG emerged as the most promising binder, offering the best overall performance for CL-20/DNDAP-based PBXs.

Conclusions:

• Polyethylene glycol (PEG) is identified as a highly suitable binder for CL-20/DNDAP cocrystal-based polymer-bonded explosives (PBXs).
• The CL-20/DNDAP/PEG composite demonstrates enhanced stability and reduced sensitivity, crucial for safer energetic materials.
• This study provides valuable insights for the design and development of next-generation insensitive high explosives.