四硝基乙酰胺酸(TNAA)的合成及热性能

以1,1'-二氨基-2,2'-二硝基乙烯(FOX-7)为原料,经浓硝酸硝化及有机溶剂萃取得到高氧平衡化合物——四硝基乙酰胺酸(TNAA)。对比了四种有机萃取溶剂(二氯甲烷、氯仿、四氯化碳和乙酸乙酯)所得TNAA的收率及纯度。采用DSC和TG研究了TNAA的热行为。结果表明,确定二氯甲烷为最佳萃取溶剂,其收率为95.0%,纯度为99.4%。升温速率10 K·min~(-1)下,TNAA熔化吸热峰的初始温度、峰值温度分别为84.8℃和87.8℃,熔融焓为61.7 J·g~(-1);分解放热峰的初始温度、峰值温度分别为117.7℃和131.4℃,分解热为934.8 J·g~(-1)。采用Kissinger方法得到的TNAA的热分解反应活化能E为124.7 k J·mol~(-1),指前因子A为10~(16.1)s~(-1)。自加速分解温度T_(SADT)为102.3℃、热爆炸临界温度T_b为112.2℃、T=Tp时TNAA热分解反应的热力学参数ΔH~≠、ΔS~≠以及ΔG~≠,分别为121.5 k J·mol~(-1)、61.2 J·K~(-1)·mol~(-1)和98.0 k J·mol~(-1)。

Synthesis and Thermal Properties of Tetranitroacetimidic Acid (TNAA)

A high oxygen balance compound-tetranitroacetimidic acid(TNAA), was synthesized via concentrated nitric acid nitrification and organic solvent extraction using 1, 1′-diamino-2, 2′-dinitroethene(FOX-7) as raw material.The yield and purity of TNAA obtained by four kinds organic solvents (dichlormethane, trichoromethane, tetrachloromethane and ethyl acetate) were compared.The thermal behavior of TNAA was studied by DSC and TG.Results show that dichloromethane is determined as the best extraction solvent and its yield and purity are 95.0% and 99.4%, respectively.At a heating rate of 10 K·min-1, the initial temperature, peak temperature and melting enthalpy of melting endothermic peak of TNAA are 84.8 ℃, 87.8 ℃ and 61.7 J·g-1 respectively, the initial temperature, peak temperature and decomposition heat of exothermic decomposition peak are 117.7 ℃, 131.4 ℃ and 934.8 J·g-1, respectively.The apparent activation energy (E) and pre-exponential constant (A) of thermal decomposition reaction obtained by Kissinger method are 124.7 kJ·mol-1 and 1016.1 s-1 , respectively.The self-accelerating decomposition temperature (TSADT), critical temperature of thermal explosion (Tb) , and thermodynamic parameters ΔH≠, ΔS≠ and ΔG≠ of thermal decomposition reaction of TNAA at T=Tp are 102.3 ℃, 112.2 ℃, 121.5 kJ·mol-1, 61.2 J·K-1·mol-1 and 98.0 kJ·mol-1, respectively.