硝酸酯的热分解性能

分别在B3LYP/6-31G*和MP2/6-31G*的理论水平下，计算得到硝酸正丙酯、硝酸异丙酯、硝酸异辛酯和二缩三乙二醇二硝酸酯4种硝酸酯的O-NO2键离解能(BDE)。 采用常压DSC和高压DSC实验方法,研究了4种硝酸酯的热分解过程，获得热分解反应动力学参数。 常压下4种物质的热分解反应发生在气相区，当压力增大至2 MPa时，4种物质直接发生液相分解反应。 4种硝酸酯的O-NO2键离解能在很大程度上符合由实验分析得到的活化能，表明4种硝酸酯的热分解反应只是单分子O-NO2键的均裂反应。

Thermal Decomposition Characteristics of Nitrates

At B3LYP/6-31G~* and MP2/6-31G~* levels,the bond dissociation energies(BDEs) of O-NO_2 bond in four nitrates such as n-propyl nitrate(NPN),isopropyl nitrate(IPN),2-ethylhexyl nitrate(EHN),and tri-ethylene glycol dinitrate(Tri-EGDN) were calculated. The thermal decomposition characteristics of NPN,IPN,EHN,and Tri-EGDN were investigated by means of ambient-pressure DSC and high-pressure DSC. Kinetic parameters of thermal decomposition were obtained. The results show that the thermal decomposition of four nitrates under ambient-pressure occurred in gas phase. When the pressure increased up to 2 Mpa,their decomposition processes occurred in liquid phase. According to the fact that the calculated results of O-NO_2 BDEs of the four nitrates are in good agreement with the experimental results of apparent activation energies obtained from DSC,we deduce that the thermolysis of the four nitrates is only unimolecular homolytic cleavage of the O-NO_2 bonds.