Chemical Evaluation and Performance Characterization of Molten Pentaerythritol Tetranitrate (PETN)

Pentaerythritol tetranitrate (PETN) is a nitrate ester explosive commonly used in commercial detonators. Although its degradation properties have been studied extensively, very little information has been collected on its thermal stability in the molten state due to the fact that its melting point is only ~20 °C below its onset of decomposition. In this work, we characterize PETN molecular decomposition and morphology changes under melt conditions utilizing a thorough suite of analytical techniques, including ultrahigh pressure liquid chromatography coupled to quadrupole time of flight mass spectrometry (UHPLC-QTOF), scanning electron microscopy (SEM), nuclear magnetic resonance spectroscopy (NMR), and differential scanning calorimetry (DSC). We estimate the amount of decomposition relative to sublimation that we measure through gas evolution, and utilize independently-prepared samples to identify products and predict melting point depression. We then tie together decomposition behavior with performance properties of both molten and re-solidified PETN in commercial detonators, using visual and X-ray imaging.