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Life-Time Prediction of Double-Base Propellants in Accordance with Serbian and NATO Standards
Ljiljana Jelisavac
This work presents the investigation of the procedure of life-time predictions of two types of double-base rocket propellants samples, NGR-176 and NGR-316, in accordance with SORS 8069/91 national standard and NATO standards: STANAG 4527 and AOP-48 Ed. 2. The samples of the examined double-base propellants were subjected to accelerated ageing in heating blocks at temperatures 80oC, 70oC and 60oC. Consumption of the ethyl centralite stabilizer in propellant samples, as a function of temperature and time, was measured by the gas-chromatography method. The experimental results of ethyl centralite consumption were mathematically described by different kinetic models. By applying the Arrhenius equation, the kinetic parameters were determined. Life-times of rocket propellants were calculated at 25oC, as the storage time, after which the critical stabilizer depletion was reached. The critical value of the stabilizer depletion is 50% of the initial stabilizer content. By comparing the results of life-times prediction of double-base propellants in accordance with different standards, the most real results were obtained in accordance with NATO standard AOP-48, Ed.2., with the description of stabilizer consumption with a kinetic expression of nth order. Key words: rocket propellant, double-base rocket propellant, ethyl centralite, life-time prediction, chemical stability, gas chromatography, standards.
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