1.3 Prediction and Rationalisation of Energetic Material Sensitivity
19
Fig. 1.13 Correlation of deformation energy to impact sensitivity. a Comparison of deformation
energies in two multi-component materials with different packing arrangements, from Ref. [92],
https://doi.org/10.1021/ja5126275. Copyright 2015 American Chemical Society. b Comparison of
deformation energies in layered vs non-layered materials, from Ref. [102], https://doi.org/10.1021/
jacs.5b07852. Copyright 2015 American Chemical Society
that packing which included non-layered components had substantially larger deformation potentials than the herringbone structure, Fig. 1.13a. The material with larger
deformation potential (and hence stored strain energy) was indeed found to be more
sensitive. The same analysis was performed for RDX (a sensitive secondary explosive) and compared to a layered compound, Fig. 1.13b [102]. Again, it was shown
that in the layered material, lower deformation potentials arose. Hence a structural
mechanism for impact sensitivity was proposed. This has led to interest in studying
the relative strengths of non-covalent interactions, primarily π…π and hydrogen
bonding interactions, which contribute to these deformation potentials [103, 104].
A recent study of PETN derivatives has also suggested that the deformability (e.g.
shear or compression) does correlate well with impact sensitivity [105]. While these
approaches have proved an intriguing direction for further research, it has not yet
been thoroughly investigated against a broad range of EMs.
19
Fig. 1.13 Correlation of deformation energy to impact sensitivity. a Comparison of deformation
energies in two multi-component materials with different packing arrangements, from Ref. [92],
https://doi.org/10.1021/ja5126275. Copyright 2015 American Chemical Society. b Comparison of
deformation energies in layered vs non-layered materials, from Ref. [102], https://doi.org/10.1021/
jacs.5b07852. Copyright 2015 American Chemical Society
that packing which included non-layered components had substantially larger deformation potentials than the herringbone structure, Fig. 1.13a. The material with larger
deformation potential (and hence stored strain energy) was indeed found to be more
sensitive. The same analysis was performed for RDX (a sensitive secondary explosive) and compared to a layered compound, Fig. 1.13b [102]. Again, it was shown
that in the layered material, lower deformation potentials arose. Hence a structural
mechanism for impact sensitivity was proposed. This has led to interest in studying
the relative strengths of non-covalent interactions, primarily π…π and hydrogen
bonding interactions, which contribute to these deformation potentials [103, 104].
A recent study of PETN derivatives has also suggested that the deformability (e.g.
shear or compression) does correlate well with impact sensitivity [105]. While these
approaches have proved an intriguing direction for further research, it has not yet
been thoroughly investigated against a broad range of EMs.