NEPE推进剂老化过程中抗拉强度的表征

Characterization of Tensile Strength of NEPE Propellant in the Aging Process

为研究NEPE推进剂老化过程中抗拉强度的变化规律,对加速老化后的NEPE推进剂进行了单向拉伸试验和傅里叶红外光谱试验;采用二阶高斯拟合与对数拟合方法分别建立了老化过程中的抗拉强度模型与强度拐点出现时间与老化温度的相关性模型;通过红外光谱数据和抗拉强度数据的相关度分析,发现了抗拉强度拐点后与其高度相关的红外特征峰。结果表明,NEPE推进剂老化过程中抗拉强度先出现波动,一段时间后抗拉强度加速下降,其强度拐点出现时间和老化温度呈对数平方关系lg2(t)=-0.217T+18.397。处于拐点后的抗拉强度可由推进剂自身红外光谱特征峰定量表征;推进剂抗拉强度与推进剂红外光谱中769cm-1与1639cm-1波数的光谱二阶导数值的加和有最大相关度,并建立了拟合方程,而这两处波长分别为O—NO2的变形振动吸收峰和不对称伸缩振动吸收峰对应的波数处;证明了利用傅里叶红外光谱表征NEPE推进剂抗拉强度的可行性。

To study the change rule of tensile strength of NEPE propellant in the aging process,the tensile test and FTIR test were carried out on the NEPE propellant after accelerated aging.Tensile strength model in aging process and the correlation model between strength inflection time and aging temperature were established by bimodal Gaussian fitting and logarithmic fitting method,respectively.Through the correlation analysis between infrared spectrum data and tensile strength data of NEPE propellant,the infrared characteristic peaks are highly correlated with the tensile strength.The results show that the tensile strength of NEPE propellant first fluctuates during aging process,and then decreases rapidly.The relationship between the time of inflection point of strength and aging temperature is logarithmic square,lg2(t)=-0.217T+18.397.The tensile strength after the inflection point can be quantitatively characterized by the IR characteristic peaks of the propellant.The tensile strength of the propellant has the maximum correlation with the sum of the spectral second derivative values of 769cm-1 and 1639cm-1 wavenumbers in the infrared spectrum of the propellant,and the fitting equation is established.The two wavelengths are the wavenumbers corresponding to the deformation vibration absorption peak and asymmetric stretching vibration absorption peak of O—NO2,respectively,proving that it is feasible to characterize the tensile strength of NEPE propellant by FTIR.