Radiation Stability of the Nitrate Ester Energetic Functional Group

High explosives (HE) are used in a variety of applications that require them to be stable under a wide range of harsh environments, and understanding how HE is altered by ionizing radiation is of particular importance. This talk will focus on the radiolytic degradation of the nitrate ester (-ONO2) functional group (FG) which is the energetic FG responsible for the explosive properties of the commonly used pentaerythritol tetranitrate (PETN). Trace chemical analyses using proton nuclear magnetic resonance (1H-NMR) and ultra high pressure liquid chromatography (UHPLC) were completed on control and γ-irradiated materials containing nitrate esters to assess chemical changes brought about by the ionizing radiation. Results indicate that the nitrate ester FG is the predominantly affected part of the molecule, and the most probable degradation pathway involves the cleavage of the trigger linkage (O-NO2).These results were found to be insufficient to explain changes in small scale sensitivity tests seen by other researchers, and thus other radiolytic changes to the materials will be discussed.