推进剂中GAP单体氮消除的反应机理

Theoretical calculation on the N2 elimination of GAP monomer

关键词:  固体推进剂  GAP单体+  分解  反应动力学

Key words:  Solid propellant  GAP monomer~+  Decomposition  Reaction kinetics

摘要:

利用B3LYP方法和TST-RRKM理论研究了GAP的一种单体CH3CHOHCH2N3的N2消除反应。计算发现该单体存在三种异构体,得到的反应势垒显示在常温下这些异构体就可以自由转换。计算结果显示有两条反应路径可以解离生成亚胺和N2,反应势垒分别为160.2kJ/mol和164.7kJ/mol,反应放热为213.7kJ/mol,与前人的实验结果相当吻合。计算得到的反应速率常数有着明显的负温度效应,并且随着反应压强的增加而增大。压强为0.1MPa时,反应速率在900K时达到极大值,为1.53×10-12cm3.mol-1.s-1。

Abstract:

The N₂elimination reactions for one of GAP （glycidyl azide polymer） monomer, CH₃CHOHCH₂N₃, were explored with B3LYP method and TST-RRKM theory. Three isomers of CH₃CHOHCH₂N₃ were considered and the calculated transition barriers indicate that these isomers can transform to others freely at room temperature. Two reaction pathways were found to yield imine and N₂ with reaction barrier of 160.2 kJ/mol and 164.7 kJ/mol, respectively. The whole process is exothermic with a released energy of 213.7 kJ/mol. These data agree well with the experimental measurements. The reaction rate constants show strong negative temperature-dependence and pressure-dependence. The rate constant reaches the maximum value of 1.53×10^-12 cm³·mol^-1·s^-1 with the pressure of 0.1 MPa and the temperature of 900 K.