HTPB/镁铝合金含量对含硼富燃推进剂压强指数影响

通过推进剂的燃速、热重(TG-DTG)分析和高压差示扫描(DSC)分析手段研究了端羟基聚丁二烯(HTPB)/镁铝合金(MA)含量变化对含硼推进剂压强指数的影响。采用燃速u与压强P的关系u=apn,求出该推进剂的压强指数n(压强范围0.5 MPa~1.5 MPa)。燃速测试实验结果表明,当HTPB/MA含量为27.3%/3%时,压强指数为0.280,而当HTPB/MA含量为20.3%/10%时,压强指数升高到0.420。通过推进剂的TG-DTG和DSC热分析可知,含硼推进剂中HTPB含量较低、MA含量较高时,推进剂失重较快,且推进剂的热分解受到压强的影响显著增强,特别是氧化剂高氯酸铵(AP)的低温分解受压强影响非常显著,因而燃速较高,压强指数也高。

Influence of HTPB/MA Content on Pressure Exponent of Boron-based Fuel-rich Propellant

The influence of hydroxyl-terminated polybutadiene(HTPB)/magnalium(MA) content on pressure exponent of boron-based fuel-rich propellant was studied by burning rate measurement,TG-DTG and DSC experiments.The pressure exponents of the propellants were obtained from u=apn.The results of the burning rate measured by experiments show that the pressure exponent is 0.280 when HTPB/MA content is 27.3%/3%,while the pressure exponent increase to 0.420 when HTPB/MA content is 20.3%/10%.It is shown by TG-DTG and DSC experiments that the burning rates and pressure exponents increase when the HTPB/MA contents decrease.The reason is that the weight-losing rate of propellant is quite quick,and the influence of pressure on pyrolysis of propellant intensifies in evidence,especially the influence of pressure on the decomposing of AP is remarkable.