✍ Scribed by M. H. Miles; K. L. Devries; A. D. Britt; W. B. Moniz
No coin nor oath required. For personal study only.
Efforts to generate detectable concentrations of free radicals in explosives, binders, and their mixtures are described. Radicals were readily produced in polycaprolactone and polyethylene glycol binders at liquid nitrogen temperature using stresses as low as 0.4 kbar. These radicals were all of the peroxy type, and presumably formed by reaction of mechano‐radicals with oxygen present in the polymer. No mechano‐radicals were observed from HMX or RDX using samples cooled to liquid nitrogen temperature and applied stresses up to 4 kbar. In neither impacted samples that failed to explode nor the residues remaining after a partial explosion were radicals detected by ESR.
Low temperature γ‐irradiation of these materials was also carried out. Free radical signals originating in both the polymer and the explosive could be identified. The reactivity of NO~2~ radicals from γ‐irradiated HMX is enhanced in the presence of binder. In γ‐irradiated HMX/polycaprolactone mixtures, the NO~2~ radical anneals rapidly at 150 K, versus 240 K for HMX alone.
Evidence is presented to suggest that the relatively stable NO~2~ radical (such as produced by γ‐irradiation) in HMX does not play a dominant role in mechanical initiation.
📜 SIMILAR VOLUMES