calorimetry (DSC) carried out with few heating rates was applied in the studies
of the thermal properties of four energetic materials: EI propellant,
high explosive PBXW-17, pyrotechnic mixtures with composition B/KNO3
(50:50) and B/KNO3 (30:70). DSC signals, after optimization
of the baseline, were used for the calculation of the kinetic parameters (KP)
of the decomposition process applying advanced kinetic software designed by
AKTS. The determination of the kinetic parameters was based on the differential
iso-conversional method of Friedman. The correctness of the estimation of
KP was checked by the comparison of the experimental and predicted courses
of the decomposition.
The slow cook-off experiments
of above mentioned energetic materials were carried out with a heating rate
of 3.3C h–1. For the simulation of the
experimental results, the heat balance based on the finite element analysis
(FEA) was applied together with the advanced kinetic description of the reaction.
The comparison of the experimental and simulated data indicates that applied
procedure resulted in a very good prediction of the temperature of the ignition.
Application of commonly used, simplified assumptions concerning the mechanism
of the decomposition (such as 1st or nth order mechanisms)
led to significantly worse prediction of the cook-off temperatures.