新型异呋咱类含能材料NOG的热行为

二氨基甘脲经体系中原位制备的二甲基过氧化酮(DMDO)氧化,制备了新型含能化合物3-硝基-5-胍基-1,2,4-噁二唑(NOG)。用扫描电镜(SEM)表征了NOG的微观形貌。用差示扫描量热法(DSC)和TG-DTA研究了NOG的热分解行为。计算了NOG放热分解反应的表观活化能、指前因子,加热速率趋于零的峰值温度(TP0)和TP0时该反应的活化熵(ΔS≠)、活化焓(ΔH≠),活化吉布斯自由能(ΔG≠)及热爆炸临界温度(Tb)。结果表明,NOG有较好的对热抵抗能力,其热分解温度为290℃,临界爆炸温度为291.56℃。其ΔS≠为232.35J·k-1·mol-1,ΔH≠和ΔG≠分别为267.36和138.42kJ·mol-1。

Thermal Behavior of 3-Nitro-5-guanidino-1,2,4-oxadiazole

3-Nitro-5-guanidino-1,2,4-oxadiazole (NOG) was obtained by oxidation of diaminoglycoluril (AG) with in situ generated dimethyldioxirane (DMDO). The particle morphological appearance of NOG prepared with the quick precipitation method was studied by scanning electron microscopy (SEM). The thermal behavior of NOG was studied by differential scanning calorimetry (DSC) and differential thermal/thermo-gravimetric analyzer (TG-DTA). The apparent activation energy (E) and pre-exponential factor (A) of the exothermic decomposition reaction,the peak temperature (TP0) of heating rate β→0, and activation entropy (ΔS≠), activation enthalpy (ΔH≠),activation Gibbs free energy (ΔG≠) at TP0 of the reaction and the critical temperature of thermal explosion (Tb) were calculated. The results show that NOG has better heat-resistance ability. The decomposition temperature of NOG is 290 ℃. The critical temperature of thermal explosion (Tb) is 291.56 ℃, ΔS≠ is 232.35 J·k-1·mol-1, ΔH≠ and ΔG≠ is 267.36 kJ·mol-1 and 138.42 kJ·mol-1, respectively.