Use of nano sized aluminium powder in place of micron sized powder leads to increase in specific impulse of solid composite propellants. However, poor mechanical properties of nano‐aluminized propellants prevent their use in actual rocket motors. An attempt has been made here, to improve the mechanical properties by using different HTPB resins having different functionality type distribution. Adjustment of isocyanate to hydroxyl ratio, and ratio of the chain extender, Butane‐diol, to the cross‐linker, Tri‐Methylol‐Propane, had also been tried to investigate their effect on mechanical properties. Nano‐aluminium content in the propellant samples could be raised to the conventional level of 18 % by use of Iso Decyl Pelargonate as plasticizer in place of Dioctyl Adipate. This made the samples at par with the conventional micro‐aluminium propellants, and the experimental results comparable. The microstructural changes of HTPB significantly improved the tensile strength of the nano‐aluminium propellants to 0.65 MPa and break elongation to 17 % respectively. Recorded heat of combustion values are at 5990 J/g. These figures meet industrial tolerance and make the propellant acceptable for use while increasing its specific impulse beyond today's conventional levels. The technology established has potentials to increase nano‐aluminium content further, and augment ballistic properties of solid motors, upholding the required industrial restrictions of rheological and physico‐mechanical parameters.

中文翻译：

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通过改变粘合剂聚合物的微观结构调整高填充纳米铝化推进剂的力学性能

使用纳米级铝粉代替微米级粉会导致固体复合推进剂的比冲增加。但是，纳米铝质推进剂的机械性能较差，无法在实际的火箭发动机中使用。这里已经尝试通过使用具有不同官能度类型分布的不同HTPB树脂来改善机械性能。还尝试调整异氰酸酯与羟基的比例以及扩链剂丁二醇与交联剂三羟甲基丙烷的比例，以研究其对机械性能的影响。通过使用异戊二酸癸基癸酯代替己二酸二辛酯作为增塑剂，可以将推进剂样品中的纳米铝含量提高到常规水平的18％。这使得样品与常规微铝推进剂相当 与实验结果可比。HTPB的微观结构变化显着将纳米铝推进剂的抗张强度分别提高到0.65 MPa和断裂伸长率分别提高到17％。记录的燃烧热值为5990 J / g。这些数字符合工业耐受性，使推进剂可以被接受使用，同时其比冲增加到超过当今的常规水平。所建立的技术有潜力进一步提高纳米铝的含量，并增强固体发动机的弹道性能，并遵守流变学和物理机械参数所要求的工业限制。65 MPa，断裂伸长率分别达到17％。记录的燃烧热值为5990 J / g。这些数字符合工业耐受性，使推进剂可以被接受使用，同时其比冲增加到超过当今的常规水平。所建立的技术有潜力进一步提高纳米铝的含量，并增强固体发动机的弹道性能，并遵守流变学和物理机械参数所要求的工业限制。65 MPa，断裂伸长率分别达到17％。记录的燃烧热值为5990 J / g。这些数字符合工业耐受性，使推进剂可以被接受使用，同时其比冲增加到超过当今的常规水平。所建立的技术有潜力进一步提高纳米铝的含量，并增强固体发动机的弹道性能，并遵守流变学和物理机械参数所要求的工业限制。