Artificial aging of crosslinked double base propellants

Bağlar, Emrah
In this study, shelf life of three different crosslinked double base (XLDB) propellants stabilized with 2-nitrodiphenylamine (2-NDPA) and n-methyl-4-nitroaniline (MNA) were determined by using the stabilizer depletion method. Depletions of the stabilizers were monitored at different aging temperatures using High Performance Liquid Chromatography (HPLC). Kinetic models of pseudo zero, pseudo first, pseudo second and shifting order were used to find the best model equation that fits the experimental data. The rates of depletion of stabilizers were calculated at 45, 55 and 65°C based on the best fit kinetic models. Using the rate constants at different temperatures, rate constants at room temperature were calculated by Arrhenius equation. The activation energies and frequency factors for the depletion of 2-NDPA and MNA were obtained for all XLDB propellants. Moreover, the results were evaluated based on the NATO standard; STANAG 4117 and the propellants were found stable according to the standard. Vacuum thermal stability (VTS) tests were also conducted to evaluate the stability of XLDB propellants. The propellant that includes the stabilizer mixture of MNA and 2-NDPA was found to have less stability than the propellants that include 2-NDPA only. However, there were rejection (puking) and migration of stabilizer derivatives for the aged samples of propellants that were stabilized with only 2-NDPA. Moreover, formation of voids and cracks were observed in block propellant samples due to excess gas generation.


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Citation Formats
E. Bağlar, “Artificial aging of crosslinked double base propellants,” M.S. - Master of Science, Middle East Technical University, 2010.