Composite solid propellants demand fine and stable mechanical properties, creep resistance and stress relaxation performance during their long storage and usage time. In this study, modified hyperbranched polyester (MHBPE) was prepared and introduced into HTPE/AP/Al/RDX (HTPE, hydroxyl‐terminated polyether; AP, ammonium perchlorate; RDX, cyclotrimethylenetrinitramine) solid propellant as an effective additive. The static tensile and dynamic mechanical properties of this propellant before and after the introduction of MHBPE were evaluated. The elevated interfacial interaction by using MHBPE between the binder and RDX fillers improved the toughness and elasticity of the propellant. The enhancement mechanisms were also confirmed by the influence on the fracture surface morphology of the binder which was investigated by SEM. In addition, some influence on the dynamic mechanical properties of HTPE/AP/Al/RDX propellant caused by MHBPE was investigated by dynamic mechanical analysis. The creep behaviors of the HTPE/AP/Al/RDX propellants with and without MHBPE were also investigated at different stresses and temperatures. Reduced creep strain rate and strain were obtained for the modified propellant, implying enhanced creep resistance performance. The creep properties were quantitatively evaluated using a six‐element model and the long‐term creep performance of the propellant was predicted using the time–temperature superposition principle. A creep behavior of nearly 10⁶ s at 30 °C could be acquired in a short‐term experiment (800 s) at 30–70 °C. Moreover, the stress relaxation investigation of the propellants with and without MHBPE at −40 °C, 20 °C and 70 °C suggested that MHBPE/HTPE/AP/Al/RDX propellant possessed better response ability to deformation. Thus, the application of MHBPE provides an efficient route of reinforcement to enhance the creep resistance and stress relaxation properties. © 2020 Society of Chemical Industry

中文翻译：

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在羟基封端的聚醚/高氯酸铵/铝/环三亚甲基三硝胺（HTPE / AP / Al / RDX）复合固体推进剂中使用改性的超支化聚酯

复合固体推进剂在长时间的储存和使用过程中需要优良且稳定的机械性能，抗蠕变性和应力松弛性能。在本研究中，制备了改性超支化聚酯（MHBPE），并将其作为有效添加剂引入HTPE / AP / Al / RDX（HTPE，羟基封端的聚醚; AP，高氯酸铵; RDX，环三亚甲基三硝胺）固体推进剂中。评估了推进剂在引入MHBPE之前和之后的静态拉伸和动态力学性能。通过在粘结剂和RDX填料之间使用MHBPE，提高了界面相互作用，从而改善了推进剂的韧性和弹性。用SEM研究了对粘合剂断裂表面形态的影响，也证实了增强机理。此外，通过动态力学分析研究了MHBPE对HTPE / AP / Al / RDX推进剂动态力学性能的影响。还研究了有和没有MHBPE的HTPE / AP / Al / RDX推进剂在不同应力和温度下的蠕变行为。改性推进剂的蠕变应变速率和应变降低，这意味着增强的抗蠕变性。使用六元素模型对蠕变特性进行了定量评估，并使用时间-温度叠加原理预测了推进剂的长期蠕变性能。蠕变行为接近10 还研究了有和没有MHBPE的HTPE / AP / Al / RDX推进剂在不同应力和温度下的蠕变行为。改性推进剂的蠕变应变速率和应变降低，这意味着增强的抗蠕变性。使用六元素模型对蠕变特性进行了定量评估，并使用时间-温度叠加原理预测了推进剂的长期蠕变性能。蠕变行为接近10 还研究了有和没有MHBPE的HTPE / AP / Al / RDX推进剂在不同应力和温度下的蠕变行为。改性推进剂的蠕变应变速率和应变降低，这意味着增强的抗蠕变性。使用六元素模型对蠕变特性进行了定量评估，并使用时间-温度叠加原理预测了推进剂的长期蠕变性能。蠕变行为接近10 使用六元素模型对蠕变特性进行了定量评估，并使用时间-温度叠加原理预测了推进剂的长期蠕变性能。蠕变行为接近10 使用六元素模型对蠕变特性进行了定量评估，并使用时间-温度叠加原理预测了推进剂的长期蠕变性能。蠕变行为接近10 在30–70°C的短期实验（800 s）中，可以在30°C的条件下获取⁶ s。此外，在-40°C，20°C和70°C下使用和不使用MHBPE的推进剂的应力松弛研究表明，MHBPE / HTPE / AP / Al / RDX推进剂具有更好的变形响应能力。因此，MHBPE的应用提供了有效的增强途径，以增强抗蠕变性和应力松弛性能。©2020化学工业协会