Applicability of Non-isothermal DSC and Ozawa Method
for Studying Kinetics of Double Base
Propellant Decomposition

 

 

Sanja Matečić Mušanić, Ivona FIAMENGO HOURA
and Muhamed Sućeska


Brodarski Institute - Marine Research & Advanced Technologies,
Av. V. Holjevca 20, 10020 Zagreb, Croatia


Abstract: 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.
kinetics of decomposition of DB propellants from non-isothermal DSC
experiments using unhermetically closed sample pans, and effect of nitroglycerine
(Ng) evaporation on the kinetic results and kinetics of Ng 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 Ng 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 Ng 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 Ng 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 DB propellant.

Keywords: double base propellant, kinetics, Ozawa method, nitroglycerine,
evaporation