NEPE推进剂动态力学特性分析

Dynamic Mechanical Properties Analysis?of NEPE Propellant

关键词:  NEPE推进剂  动态力学分析  玻璃化转变温度  时间-温度等效原理

Key words:  NEPE propellant  Dynamic mechanical analysis  Glass transition temperature  Time-temperature equivalence

摘要:

为了研究NEPE推进剂在不同温度和频率激励作用下的动态力学性能，利用DMA-ELF3200动态热机械分析仪测定了材料动态力学参数。通过试验，获得了推进剂的储能模量、损耗模量及损耗因子温度谱。由分子运动理论得到了玻璃化转活化能。基于时间-温度等效原理对NEPE推进剂动态粘弹性参数进行等效叠加，得到了移位因子随试验温度变化的规律。结果表明:损耗模量的温度谱曲线在低温段只存在一个峰值(玻璃化转变峰)，玻璃化转变温度对频率有依赖性，在1Hz加载频率下转变温度为-62℃；玻璃化转变所需要的活化能为163.8kJ·mol-1；移位因子和温度之间的关系遵循Williams-Landel-Ferry (WLF)方程，随试验温度升高，移位因子下降 。

Abstract:

In order to determine dynamic mechanical behavior of NEPE propellant under different excitation frequencies and temperature，the dynamic mechanical analyzer (DMA-ELF3200) was employed to measure dynamic viscoelastic parameters. Temperature spectrums of storage modules，loss modules and loss tangent were obtained through?experiment. The glass-transition activation energy was obtained based on the kinetic molecular theory. The dynamic?viscoelastic parameters were superimposed from the time-temperature equivalence principle. The?change?patterns of the shift factors?with?temperature were found?out. The results show that only one single relaxation peak exists in loss modulus-temperature curves in the low temperature region，which is glass transition relaxation peak. Glass transition temperature is dependent on the loading frequencies. The?glass?transition?temperature is -62℃ in frequency 1 Hz. The activation energy is about 163.8kJ·mol-1.The relationship between shift factors? and temperature follows Williams-Landel-Ferry (WLF) equation. The?shift factor?drops as the?temperature?rises.