Simulation and Experimental on the Solvation Interaction between the GAP Matrix and Insensitive Energetic...

Area of Science:

• Materials Science
• Polymer Chemistry
• Computational Chemistry

Background:

• Energetic materials require compatible matrices and plasticizers for optimal performance and safety.
• Glycidyl azide polymer (GAP) is a promising energetic polymer matrix.
• Insensitive energetic plasticizers are crucial for reducing sensitivity while maintaining energy output.

Purpose of the Study:

• To investigate the interaction mechanisms between the GAP matrix and two insensitive energetic plasticizers: N-butyl-N-(2-nitroxy-ethyl)nitramine (Bu-NENA) and bis(2,2-dinitropropyl)formal/acetal (BDNPF/A).
• To evaluate the miscibility and compatibility of these plasticizers within the GAP matrix.
• To correlate interaction strength with macroscopic properties like glass transition temperature and mechanical performance.

Main Methods:

• Multimethod approach combining simulation and experimental techniques.
• Calculation of blending energy distribution and Huggins parameters for miscibility assessment.
• Solubility parameter and binding energy calculations to quantify compatibility.
• Low-field NMR for physical cross-link density determination.
• Dynamic rheological and mechanical testing to assess material behavior.

Main Results:

• High miscibility was observed between the GAP matrix and both Bu-NENA and BDNPF/A.
• Bu-NENA exhibited superior compatibility with the GAP matrix compared to BDNPF/A, evidenced by stronger binding energies and solubility parameters.
• Interaction mechanisms involve hydrogen bonds and van der Waals forces.
• Bu-NENA demonstrated a greater disentanglement effect in the GAP matrix.
• GAP/Bu-NENA blends showed a lower glass transition temperature, indicating stronger polymer-plasticizer interactions.

Conclusions:

• Bu-NENA demonstrates significantly stronger interactions and better compatibility with the GAP matrix than BDNPF/A.
• The enhanced compatibility of Bu-NENA is attributed to a combination of hydrogen bonding and van der Waals forces.
• These findings suggest that Bu-NENA is a more suitable energetic plasticizer for the GAP matrix, potentially leading to improved performance and safety characteristics in energetic formulations.