Study on Cellulose Acetate Butyrate/Plasticizer Systems by Molecular Dynamics Simulation and Experimental...

Area of Science:

• Materials Science
• Polymer Chemistry
• Energetic Materials

Background:

• Cellulose acetate butyrate (CAB) is a common binder in polymer bonded explosives (PBXs).
• Poor mechanical properties of CAB-based PBXs lead to cracking issues.
• Plasticizers are crucial for enhancing binder performance.

Purpose of the Study:

• To evaluate seven plasticizers for their compatibility with CAB.
• To predict and improve the mechanical and processing properties of CAB/plasticizer systems.
• To guide the formulation of improved PBXs using CAB binders.

Main Methods:

• Molecular dynamics simulations to assess compatibility and predict mechanical properties.
• Analysis of solubility parameters, binding energies, and radial distribution functions.
• Experimental characterization using FT-IR, DSC, DTA, and tensile tests.

Main Results:

• Bis(2,2-dinitro propyl) formal/acetal (A3), Bu-NENA, diethylene glycol bis(azidoacetate) (DEGBAA), and glycidyl azide (GAPA) showed good compatibility with CAB via simulation.
• Experimental results confirmed the compatibility of A3, GAPA, and Bu-NENA with CAB.
• CAB/A3 exhibited the highest tensile strength and Young's modulus, while CAB/Bu-NENA showed the best strain at break.

Conclusions:

• A3, Bu-NENA, and GAPA are identified as highly suitable plasticizers for CAB binders.
• These plasticizers significantly improve the mechanical and processing properties of CAB-based PBXs.
• The findings offer critical guidance for designing advanced PBX formulations.