T-Jump/FTIR技术研究3,4-二硝基呋咱基氧化呋咱快速热裂解

采用温度快速跃迁原位池与快速扫描傅里叶变换红外联用(T-Jump/FTIR)技术在0.1-0.4MPa压强范围内研究了3,4-二硝基呋咱基氧化呋咱(DNTF)的快速热裂解.试验是以1000℃·s-1的升温速率在800和1000℃的温度下进行,用快速扫描傅里叶变换红外光谱实时跟踪分析DNTF裂解的气相产物.结果表明,DNTF快速热裂解的主要产物CO、CO2、NO和NO2的相对摩尔浓度c*与温度和压强有关,通过分析相对摩尔浓度比(c*NO/c*NO2)随温度和压强的变化,揭示了DNTF中碳硝基C—NO2存在均裂生成NO2和异构化生成NO两条竞争分解的可能途径,同时压强可能抑制呋咱环和氧化呋咱环生成NO的可能性.压强升高使c*CO和c*CO2升高,而使c*CO/c*CO2下降,证明DNTF的分解中存在非均相的气相/凝聚相反应和均相的气相产物间反应的二次或三次过程.

Investigation on the Flash Thermolysis of 3,4-Dinitrofurazan-furoxan by T-Jump/FTIR Spectroscopy

The fast thermolysis of 3,4-dinitrofurazanfuroxan (DNTF) at 0.1-0.4 MPa was investigated by temperature-jump Fourier transform infrared (T-jump/FTIR) spectroscopy. All tests were carried out using a heating rate of 1000℃· s~(-1) at 800 and 1000℃. Structures and concentrations of the gaseous products were obtained in situ and in real time by fast scanning FTIR. Results showed that the relative molar concentrations c~* of the main gaseous products (CO, CO_2, NO and NO_2) that were released by the thermolysis of DNTF were related to pressure and temperature. The relative molar concentration ratios of c_(NO)~*/C_(NO_2)~* changes as the temperature and pressure change. These results reveal that the two competitive reactions of C-NO_2 homolysis (to form NO_2) and isomerization (to form NO) may occur during the fast thermolysis of DNTF. NO formation from the cracking of furazan or furoxan rings may be limited by pressure. Heterogeneous gas/condensed phase and homogeneous gas phase reactions may occur in the secondary and tertiary class reactions of the fast thermolysis of DNTF because the relative molar concentrations of c_(co)~* and c_(co_2)~* increase and the relative molar concentration ratios of c_(co)~*/c_(co_2)~* decrease with increasing pressure.