In order to study the ageing behaviour of advanced energetic propellants during storage and the effect of nitrate ester on the shelf life, accelerated ageing tests were conducted on two types of propellants based on nitrate esters, BTTN (as P‐1) and NG:BTTN (1 : 1) mixture (as P‐2). Mechanical and ballistic characterization of P‐1 and P‐2 propellants were carried out during storage at ambient (27 °C) and elevated temperature (40 °C and 55 °C). During ageing, tensile strength and Young‘s modulus of propellants are increasing and percentage elongation is decreasing due to depletion of nitrate ester from the locus. Also, there is a loss of stabilizer with time during ageing. Thermal decompositions of P‐1 and P‐2 were studied using differential thermal analysis at four heating rates (1 °C/min, 2 °C/min, 5 °C/min, and 10 °C/min) during ambient and accelerated ageing. Activation energies for thermal decomposition were calculated using Kissinger's and Ozawa's methods by assuming first‐order reaction kinetics for first stage decomposition in DSC studies of aged propellants. The shelf life of propellants was predicted based on the classical Arrhenius equation using zero‐order kinetics of degradation of the propellant mechanical property i. e. percentage elongation. With the 30 percentage elongation as the critical evaluation parameter, predicted shelf life at 25 °C is 23.97 years and 12.17 years for P‐1 and P‐2 respectively.

中文翻译：

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老化对高级含能推进剂的热，弹道和力学性能的影响研究

为了研究高级含能推进剂在储存过程中的老化行为以及硝酸酯对保质期的影响，对两种基于硝酸酯的推进剂进行了加速老化测试，BTTN（作为P-1）和NG：BTTN （1：1）混合气（如P‐2）。在环境温度（27°C）和高温（40°C和55°C）下储存期间，对P-1和P-2推进剂进行了机械和弹道表征。在老化过程中，推进剂的抗张强度和杨氏模量不断增加，而伸长率的百分比却在下降，这是由于硝酸酯从场所中消耗掉了。而且，老化过程中会随着时间的流逝而失去稳定剂。使用差热分析以四种加热速率（1°C / min，2°C / min，5°C / min，和10°C / min）的环境老化和加速老化过程中。热分解的活化能使用基辛格（Kissinger）和小泽（Ozawa）的方法，通过在老化推进剂的DSC研究中假设第一阶段分解的一级反应动力学来计算。推进剂的保质期是根据经典的阿伦尼乌斯（Arrhenius）方程使用推进剂力学性能i的零级降解动力学进行预测的。e。伸长率百分比。以30％的伸长率作为关键评估参数，对于P-1和P-2，在25°C下的预计货架寿命分别为23.97年和12.17年。推进剂的保质期是根据经典的阿伦尼乌斯（Arrhenius）方程使用推进剂力学性能i的零级降解动力学进行预测的。e。伸长率百分比。以30％的伸长率作为关键评估参数，对于P-1和P-2，在25°C下的预计货架寿命分别为23.97年和12.17年。推进剂的保质期是根据经典的阿伦尼乌斯（Arrhenius）方程使用推进剂力学性能i的零级降解动力学进行预测的。e。伸长率百分比。以30％的伸长率作为关键评估参数，对于P-1和P-2，在25°C下的预计货架寿命分别为23.97年和12.17年。