Relative explosive strength of some explosive mixtures containing urea and/or peroxides

Several mixtures, based on urea, urea derivatives some inorganic oxidants, including also aluminia, were studied by means of ballistics mortar with TNT as a reference standard. The Detonation pressure (P), detonation velocity (D), detonation heat (Q) and volume of gaseous product at standard temperature and pressure conditions (STP condition) were calculated using Explo5 V6.3 thermochemical code. The performance of the mixtures studied was discussed in relation to their thermal reactivity, determined by means of differential thermal analysis (DTA) . It is shown that the presence of hydrogen peroxide in the form of its complex with urea (i.e. as UHP) has positive influence on the explosive strength of the corresponding mixtures which is linked to the hydroxy-radical formation in the mixtures during their initiation reaction. These radicals may might initiate (at least partially) powdered aluminium into oxidation in the CJ plane of the detonation wave. Mytures containing UHP and magnesium are dangerous because of potential auto-ignition.