磷酸三丁酯与NO2反应研究

通过气相色谱仪和气相色谱-质谱联用仪对磷酸三丁酯（TBP）与NO₂反应的气相产物和液相产物进行表征，气相产物主要是1-丁烯、CO、N₂等，液相产物表征出的组分有硝酸丁酯和未反应的磷酸三丁酯。使用绝热加速量热仪（ARC）对不同摩尔比例反应体系的具体参数进行测量，通过Arrhenius方程对参数拟合得到反应的动力学参数，分别通过基于第一性原理的分子动力学模拟对反应过程与产物进行进一步分析。结果表明：纯TBP的起始放热温度为285.6 ℃，加入不同比例NO₂后样品起始放热温度降低到80~90 ℃，随着NO₂比例的增加，样品的最大温升速率和压升速率有较大提升，整个体系的热危险性急剧增加。除去个别由于冷凝回流导致活化能未被准确测量的样品，其余样品活化能约为10~12 kJ/mol。TBP在NO₂存在时C-O键会快速断裂。结合体系中有NO和OH片段生成的现象，猜测反应路径可能是NO₂夺取TBP上H原子生成HONO，这一过程导致TBP分子快速分解，生成1-丁烯和反式2-丁烯。

Reaction of Tributyl Phosphate With Nitrogen Dioxide

The gas phase and liquid phase products of tributyl phosphate(TBP) reaction with nitrogen dioxide were characterized by gas chromatograph and gas chromatography-mass spectrometry. Gas phase products are mainly 1-butene, CO, N₂, etc, and the liquid phase products are characterized by butyl nitrate and unreacted tributyl phosphate. The adiabatic accelerated calorimeter(ARC) was used to measure the specific parameters of the reaction systems with different molar ratios, the kinetic parameters of the reaction were obtained by Arrhenius equation fitting, the reaction process and products were further analyzed by first-principles molecular dynamics simulation. The results show that the initial exothermic temperature of pure TBP is 285.6 ℃, after adding different proportion of NO2, the initial exothermic temperature of the sample is reduced to 80-90 ℃, with the increase of the proportion of NO2, the maximum temperature rise rate and pressure rise rate of the sample increase greatly, and the thermal hazard of the whole system increases sharply. The activation energies of the other samples are about 10.12 kJ/mol, excluding a few samples whose activation energies are not accurately measured due to condensation reflux. In the presence of NO₂, TBP rapidly breaks the C-O bond. NO and OH fragments are generated in the binding system, and it is speculated that the reaction path may be NO₂ capturing H atoms on TBP to generate HONO. This process leads to the rapid decomposition of TBP molecules to generate 1-butene and trans-2-butene.