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Voltammetric behavior of potassium salt of 2,4-dinitrobenzofuroxan (KDNBF) has been firstly studied using hanging mercury drop electrode (HMDE) and silver solid amalgam electrode (AgSAE). Cyclic voltammetry was applied for the measurements of dependences on pH and scan rate required for the elucidation of the ongoing electrode reactions and differential pulse voltammetry served for the development of sensitive method for KDNBF determination. Bylo studováno voltametrické chování draselné soli 2,4-dinirobenzofuroxanu s využitím visící rtuťové kapkové elektrody a stříbrné pevné amalgámové elektrody.

In order to determine Arrhenius kinetic constants various experimental techniques and testing conditions have been used. Also, various kinetic approaches and data treatment procedures have been applied, resulting sometimes in considerable disagreement in the values of the kinetic parameters reported in literature. The non-isothermal differential scanning calorimetry (DSC) measurements and isoconversional Ozawa kinetic method are very often used to study kinetics of energetic materials. However, in some cases the Ozawa method is used uncritically, i.e. not taking into account some limitations of the method and possible dependence of experimental data on testing conditions. In our previous studies on double base and single base propellants we have shown that testing conditions (sample mass, heating rate, type of sample pan, etc.) may considerably affect kinetic results. An unusual behaviour that manifests in existence of a discontinuity and slope change of the Ozawa plot has been observed in the case of double base propellants. We have explained such behaviour by the sample self-heating effects. In this paper we have studied kinetics of decomposition of double base propellants from non-isothermal DSC experiments using unhermetically closed sample pans, and effect of nitroglycerine evaporation on the kinetic results. Kinetics of nitroglycerine evaporation has been studied by isothermal thermogravimetry. It has been shown by experiments and numerical simulation that at slower heating rates and smaller sample mass nitroglycerine may completely evaporate before DSC peak maximum, resulting in a higher values of the activation energy (173 kJ/mol). At faster heating rates and larger sample masses certain amount of nitroglycerine still exists in the propellant at the peak maximum temperature, resulting in lower values of the activation energy (142 kJ/mol). The discontinuity point on the Ozawa plot is connected with the presence of nitroglycerine in the propellant at DSC peak maximum temperature. This implies that the activation energy obtained using small samples and slow heating rates (173 kJ/mol) corresponds to the activation energy of decomposition of nitrocellulose from double base propellant.

When determining firing impulse, electric current through detonator is measured. The current can be measured by measuring voltage drop over known resistance or by magnetic effects of electric current. Shape of current pulse influences the possi-bility to use transducer with magnetic effects. Rise time of pulse limits the possibil- ity to choose a recorder of appropriate bandwidth and necessary resolution. There-fore, the measurement system with possibility to create rectangular and sine shape was assembled, and measurements of firing impulse with both current pulse shapes were conducted on the same type of detonators.