engleski

Determination of Arrhenius kinetic constants for duble base propellants by non-isothermal DSC measurement. Influence of sample self-heating

In order to predict with required accuracy the shelf-life and thermal hazard potential of an explosive material a true decomposition mechanism and true kinetic constants should be known. Various experimental techniques and experimental conditions, various kinetic approaches and data treatments procedures have been applied in order to evaluate Arrhenius’ kinetic constants from experimental data as accurately as possible. Consequently, the kinetic constants for an energetic material reported in literature may be in considerable disagreement. In this paper we studied the influence of propellant sample self-heating degree on the values of Arrhenius kinetic constants, using non-isothermal DSC measurements and the isoconversional kinetic approach described by Ozawa, and Flynn and Wall. The results have shown that Ozawa method is capable of producing valid results for double base propellants, provided that self-heating is minimised by adjustment of the experimental conditions. The activation energy was calculated to be ~173 kJ/mol in the case when sample self-eating has been avoided, while in the case of samples self-heating existence the activation energy was calculated to be ~140 kJ/mol.

thermal analysis; self-heating; double base propellant; stability

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