The assessment of the real in-service-time (RIST) and the equivalent in-service-time (EIST) of double base rocket propellants (DBRPs) is of utmost importance for the safe storage and use of weapon systems as well as the efficiency of the accelerated aging plans. In this work, four DBRPs with similar chemical composition and different natural aging have been artificially aged at T = 338.65 K for 4 months with sampling every 30 days. The unaged and artificially aged samples have been investigated by vacuum stability test (VST) at five isothermal temperatures (T = 333.15 K, 343.15 K, 353.15 K, 363.15 K, and 373.15 K). The volume of the evolved gases in VST was found to decrease with natural/artificial aging. Furthermore, the VST data were treated and subjected to principal component analysis (PCA). The results showed excellent discrimination of the DBRP samples according to their stability thermal properties. Most of the variance was described by the first principal component (PC1) whose scores were linearly correlated with the natural aging durations when PCA is applied on VST data obtained at T = 363.15 K. In light of the obtained results, a new experimental way for the estimation of the real/equivalent IST was proposed, which takes into account the impact of the natural aging of the sample. The approach predicts successfully the RIST of two similar DBRPs with a relative deviation of less than 2%. At the specific heating temperature T = 338.65 K, the developed model provides more conceivable EIST values, with asymptotic behavior against artificial aging duration evolution, thus overcoming some shortcomings of the common generalized van’t Hoff formula (GvH).

对双基火箭推进剂（DBRP）的实际服役时间（RIST）和等效服役时间（EIST）的评估对于安全存储和使用武器系统以及提高效率至关重要。加速老化计划。在这项工作中，四个具有相似化学成分和不同自然老化的DBRP已在T  = 338.65 K下人工老化4个月，每30天采样一次。未老化和人工老化的样品已通过在五个等温温度（T = 333.15 K，343.15 K，353.15 K，363.15 K和373.15 K）。发现随着自然/人工老化，VST中放出的气体量减少。此外，对VST数据进行了处理并进行了主成分分析（PCA）。结果表明，根据DBRP样品的稳定性，热性能，它们具有出色的判别力。大部分差异由第一主成分（PC1）描述，当PCA应用于在T处获得的VST数据时，其分数与自然老化持续时间线性相关 = 363.15K。根据获得的结果，提出了一种新的估算真实/等效IST的实验方法，其中考虑了样品自然老化的影响。该方法成功地预测了两个相似DBRP的RIST，相对偏差小于2％。在特定的加热温度T  = 338.65 K时，开发的模型提供了更合理的EIST值，并且具有针对人工衰老持续时间演变的渐近行为，因此克服了通用广义van't Hoff公式（GvH）的一些缺点。