复合推进剂中的降速剂

Additives of lowing the burning rate in composite propellants

关键词:  固体推进剂  复合推进剂  添加剂  燃速调节剂  燃速测试  热分析

Key words:  Solid propellant  Composite propellant  Additive  Burning rate modifier  Burning rate testing  Thermal analysis

摘要:

采用燃速测量、热分析等技术,研究了草酸铵、碳酸锶、碳酸锶/草酸铵、碳酸锶/草酰胺等添加剂对AP/HTPB系推进剂燃速的影响。结果显示,上述几种添加剂均可不同程度地使推进剂燃速降低,其原因是添加剂促使AP的分解峰温向高温方向移动以及使AP分解的活化能增加。不同添加剂的影响机理有所不同:草酸铵的分解产物阻碍AP低温、高温分解,从而使AP分解峰向高温方向移动;碳酸锶和AP分解产物高氯酸反应产生不易分解的高氯酸锶使AP分解峰温升高;同时由燃速测试结果发现,在压强大于5MPa时,碳酸锶/草酸铵、碳酸锶/草酰胺产生协同作用,使推进剂降速效果非常明显,尤其是碳酸锶与草酰胺的组合,不但使推进剂燃速降低明显,而且压强指数的降低幅度也最大,是一种良好的复合型降速剂。

Abstract:

AP/HTPB based composite propellants with additives such as ammonium oxalate （AO）, strontium carbonate （SC）, mixture of ammonium oxalate / strontium carbonate and mixture of oxalamide （EDA）/strontium carbonate were investigated by burning rate experiments and TG/DTG analysis. The results showed that the burning rates of these propellants were decreased. Not only decomposition temperatures of AP with these additives were increased,but also their activation energy were also increased. Because of these, the burning rates of these propellants were decreased. Analysises were proved that the decomposition products of ammonium oxalate impediment decomposition of AP in low temperature or high temperature. The reaction of strontium carbonate with perchloric acid produced Sr（ClO₄）₂ which is difficult to decompose and increase the peak temperature of AP decomposition. Results of burning rate experiments also showed that mixture of ammonium oxalate/strontium carbonate and mixture of oxalamide/strontium carbonate have strongly coordinative effects on reducing AP/HTPB propellants burning rate when the pressure is more than 5 MPa. Especially, mixture of oxalamide/strontium carbonate not only can decrease burning rate of propellants, but also pressure exponent is the lowest.