Cycled DSC-analysis of HNS in energetic melts

Abstract. Using hexanitrostilbene (HNS) and trinitrotoluene (TNT) as an example combination, a cycled calorimetric study (DSC) is presented which shows measured effects of successful (and unsuccessful) crystallization seeding. Further common energetic melts such as ammonium dinitramide (ADN), pentaerythritol tetranitrate (PETN) and Tetryl were investigated as reference substances. Melt separation effects in DSC samples are shown and interpreted. The comparison of zero-samples with HNS-doped solidification samples showed different, material specific kinetic responses, with strong statistical variations. DSC data of tetryl melting and recrystallization show unexpected signals, interpreted as extraordinarily strong supercooling with crystallization on the heating path, requiring further corroboration. Calorimetry and optical polarization microscopy enable the in-situ observation of relevant crystallization processes. Possible additives and their effects can thus be directly observed during crystallization. The potential benefits of temperature-resolved single-crystal structure determination (S-XRD) for such investigations are discussed.