This work uses the change of elongation with temperature in a composite solid propellant to assess its shelf life for the air and nitrogen atmospheres applying two methods for the temperature parameterization of the measured quantity, the Arrhenius and Berthelot equation. The samples of the composite propellant contain aluminum (Al), ammonium perchlorate (AP), and hydroxyl‐terminated polybutadiene (HTPB) as well as curing agent toluene diisocyanate (TDI), which were aged at three temperatures 323.15, 333.15, and 343.15 K during 15, 30, 60, 90, and 120 days. Stress‐strain curves for the samples are investigated to study the effects of the atmospheres of air and nitrogen on the samples. The ratio of the changes in percentage elongation (ϵ) to the initial value of percentage elongation (ϵ_r) is the degradation criterion, which is defined as a reduction of the elongation to less than 50 %. The calculated activation energy by the Arrhenius method is 80.48 kJ mol⁻¹ for the air atmosphere. The shelf life of the samples were found to be 7.912 and 7.906 years (air atmosphere) to 23.38 and 23.36 years (nitrogen atmosphere) as well as Arrhenius and Berthelot methods, respectively.

中文翻译：

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利用伸长率变化比较复合固体推进剂在空气和氮气中的保存期限

这项工作使用复合固体推进剂的伸长率随温度的变化来评估其在空气和氮气气氛中的保质期，并使用两种方法对被测量进行温度参数化，即Arrhenius和Berthelot方程。复合推进剂的样品包含铝（Al），高氯酸铵（AP）和羟基封端的聚丁二烯（HTPB）以及固化剂甲苯二异氰酸酯（TDI），它们在323.15、333.15和343.15 K的三个温度下进行了时效处理在15、30、60、90和120天内。研究了样品的应力-应变曲线，以研究空气和氮气气氛对样品的影响。的变化百分比伸长率（比率ε到伸长率的初始值）（ε_r）是退化标准，定义为伸长率降低到小于50％。通过Arrhenius方法计算得出的活化能对于空气是80.48 kJ mol ^-1。样品的货架期分别为7.912和7.906年（空气气氛）至23.38和23.36年（氮气气氛），以及Arrhenius和Berthelot方法。