NEPE推进剂老化过程中抗拉强度的表征

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.