4种硝酸酯热安定性的绝热试验研究

利用绝热加速量热仪(ARC)对硝酸正丙酯(NPN)、硝酸异丙酯(IPN)、太根(TEGDN)、敌根(DEGDN)4种硝酸酯的热稳定性进行了绝热试验研究,得到绝热放热曲线和热分解特征参数。分析了4种物质分解过程的特点,对测试结果进行了修正。计算得到动力学参数和自加速分解温度SADT,以此作为评估热安定性的判据。结果表明,4种硝酸酯在外界热作用下容易发生分解,反应速度较快,伴随明显的热效应和压力效应。4种硝酸酯的热安定性由好到差排序为:IPN、NPN、TEGDN、DEGDN。

Research on the thermal stability of four nitrates by accelerating the rate calorimeter

In order to investigate the thermal stability and thermal decomposition properties of the four nitrates,that is,n-propyl nitrate(NPN),isopropyl nitrate(IPN),triethylene glycol dinitrate(TEGDN) and diethylene glycol dinitrate(DEGDN),this paper has studied the decompositions of NPN,IPN,TEGDN and DEGDN by accelerating the rate calorimeter(ARC) under the adiabatic environment.In the paper,we have also presented the curves of the thermal decomposition temperature and pressure vs the time and temperature increasing rate and pressure rising rate vs the temperature in Fig.1 and Fig.2.And in turn we have obtained the thermal decomposition characteristics of the four nitrates,that is,the onset temperature,the initial temperature rising rate and the maximum temperate rising rate.Later,we have worked out the test decomposition characteristics corrected by the thermal inertia factors,with the kinetic parameters of NPN,IPN,TEGDN and DEGDN,such as apparent activation energy and pre-exponential factors of the thermal decomposition,worked out according to the adiabatic theory.And,finally,we have estimated simultaneously the self-accelerating decomposition temperatures(SADT) of four nitrates in three different containers(4.5 L iron drum,25 L iron drum and 210 L fiber drum).Thus,it can be concluded that the onset temperature of NPN,IPN,TEGDN and DEGDN were 149.81 ℃,156.64 ℃,150.58 ℃ and 150.65 ℃ respectively,whereas the maximum temperature rising rates of NPN,IPN,TEGDN and DEGDN were 18.15 ℃·min-1,12.13 ℃·min-1,59.68 ℃·min-1 and 209.79 ℃·min-1,with the maximum pressures per unit of NPN,IPN,TEGDN and DEGDN being 8.56 MPa·g-1,9.89 MPa·g-1,8 MPa·g-1 and 5.21 MPa·g-1,the apparent activation energy of NPN,IPN,TEGDN and DEGDN—214.36 kJ·mol-1,213.77 kJ·mol-1,226.39 kJ·mol-1 and 214.53 kJ·mol-1.According to SADT,the thermal stability of the four nitrates proves to be comparatively dependable,with the thermal stability of DEGDN being the poorest,and the thermal stability of TEGDN—slightly better than that of DEGDN.However,the thermal stability of NPN tends to be better than that of TEGDN,and the thermal stability of IPN turns to be the best.