Quantification of Impact Sensitivity Based on Solid-State Derived Criteria

Area of Science:

• Materials Science
• Computational Chemistry
• Chemical Engineering

Background:

• Understanding the impact sensitivity of explosives is crucial for safety and performance.
• Existing methods for assessing impact sensitivity often rely on empirical data and experimental testing.
• A theoretical framework is needed to predict and explain the varying impact sensitivities of different explosive compounds.

Purpose of the Study:

• To develop a general theoretical description of impact sensitivity for C-H-N-O-Cl explosives.
• To establish quantifiable criteria for predicting impact sensitivity based on solid-state properties.
• To correlate theoretical predictions with experimental impact sensitivity data.

Main Methods:

• Utilized first-principles calculations to study 24 explosives with a wide range of impact sensitivities (h50 = 9-320 cm).
• Developed a theoretical approach based on solid-state criteria: triggering pressure, average electrons per atom, crystal morphology, energy content, and melting temperature.
• Investigated the influence of crystal compression, crystal habit, and energy content under external pressure.

Main Results:

• An empirical correlation between the developed criteria and impact sensitivity was established with a significant regression coefficient (R² = 0.83).
• The criteria were found to be complementary, with individual criteria showing poor correlation.
• Sensitive explosives are characterized by easier conversion to metal upon compression, spherical crystal habit, higher electron density, greater energy content, and lower melting temperature.

Conclusions:

• A comprehensive theoretical model for impact sensitivity has been successfully developed.
• The combined solid-state criteria provide a robust method for predicting explosive impact sensitivity.
• This approach offers a deeper understanding of the fundamental factors governing the impact behavior of energetic materials.