Theoretical shock sensitivity index for explosives.

Area of Science:

• Chemistry
• Materials Science
• Physical Chemistry

Background:

• Predicting the shock sensitivity of energetic materials is crucial for safety and performance.
• Existing methods often rely on empirical fitting or complex calculations.
• Understanding the molecular basis of sensitivity is key to designing safer explosives.

Purpose of the Study:

• To develop a practical and physically grounded shock sensitivity index for nitro compounds.
• To correlate this index with experimental shock sensitivity data.
• To provide new insights into structure-sensitivity relationships in energetic materials.

Main Methods:

• Calculating the ratio of weakest bond dissociation energy to decomposition enthalpy per covalent bond.
• Correlating this ratio with experimentally determined shock sensitivity data for 16 diverse explosive molecules.
• Developing a linear regression model for predictive purposes.

Main Results:

• The proposed index shows a strong correlation (R ≥ 0.95) with experimental shock sensitivity data.
• The index successfully predicts sensitivity across major families of explosive compounds without empirical fitting.
• A linear regression model based on this index outperforms previous predictive methods.

Conclusions:

• The developed shock sensitivity index provides a reliable and physically interpretable measure of explosive material sensitivity.
• Sensitivity is fundamentally linked to the material's energy content and the propagation of decomposition events.
• This approach offers a more profound understanding of molecular determinants of sensitivity, explaining behaviors of compounds like TATB and FOX-7.