Computational studies of impact sensitivity in energetic plasticizers – using DFT on BuNENA, MeNENA and DINA
About the publication
Report number
23/01908
ISBN
978-82-464-3493-3
Format
PDF-document
Size
2.7 MB
Language
English
Energetic materials are key constituents in rocket propellants. Modern solid rocket propellants
contain energetic plasticizers, whose purpose is to adjust propellant properties such as thermal
stability, energy content, mechanical properties, oxygen balance and burning behavior. We
studied the impact sensitivity of three such energetic plasticizers.
In this project, we studied the energetic plasticizers 2-[butyl(nitro)amino]ethyl nitrate (BuNENA),
2-[methyl(nitro)amino]ethyl nitrate (MeNENA) and (nitroazanediyl)bis(ethane-2,1-diyl) dinitrate
(DINA). We tried to predict their impact sensitivity based on molecular bonding energies using
density functional theory with the exchange-correlation functional M06-2X and the TZVP basis
set. We studied two different elimination reactions: homolytical dissociation of nitro groups and
elimination of nitrous acid.
Based on these calculations, the O–NO2 bond is the one that breaks the easiest, which is
consistent with the literature. We also showed that these bonds are stronger in BuNENA than
in MeNENA and DINA, and that the latter two have similar bond strengths. This finding is
not consistent with experimentally measured sensitivity. Therefore, the difference in impact
sensitivity indicated in the literature cannot be explained solely by the dissociation energy of
the nitro group. The elimination of nitrous acid should be studied more thoroughly to gain an
improved understanding.
We also performed a comparison of some different exchange-correlation functionals with coupledcluster
singles and doubles with perturbed triples. Our results showed that the bond dissociation
energy calculated with a CAM-B3LYP functional was closest to the coupled-cluster result.
Finally, we carried out a fallhammer experiment on BuNENA. Our experiment showed significantly
lower impact sensitivity than reported in the literature. This may be due to variations in the
experimental method. Further investigations should therefore be conducted.
Publisher information
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