摘要
使用加速量热仪研究硝酸正丙酯(NPN)、硝酸异丙酯(IPN)和硝酸异辛酯(EHN)的热分解过程.分析了在绝热条件下热分解反应动力学,根据实验数据计算出表现活化能、指前因子和反应热等参数.根据NPN、IPN和EHN热分解的起始温度和反应热数据,给出了三种硝酸酯在75℃时的反应风险指数,分析得到三种物质的热失稳风险度.分别在B3LYP/6-31+G(2df,2p)和B3P86/6-3l+G(2df,2p)的理论水平下,计算得到NPN、IPN和EHN的O—NO_2键离解能(BDE).由NPN、IPN和EHN的O—NO_2键离解能在很大程度上符合由加速量热仪测试得到的活化能,推知三种硝酸酯的热分解反应只是单分子O—NO_2键的均裂反应.
The thermal decomposition of n-propyl nitrate （NPN）, isopropyl nitrate （IPN）, and 2-ethyl- hexyl nitrate （EHN） were investigated using an adiabatic calorimeter called ARC （Accelerating Rate Calorimetry）. The thermolysis kinetics under adiabatic condition were analyzed, and kinetics parameters such as apparent activation energy, pre-exponential factor and reaction heat were calculated according to test data. According to the onset temperature （Toner） and heat of reaction （--AH） of NPN, IPN, and EHN, their reactivity risk index （RRI） at 75 ℃ and thermal instability were also gained. Under B3LYP/ 6-31-kG（2df,2p） and B3P86/6-31＋G（2df,2p） levels, the bond dissociation energies （BDEs） of O-NO2 bond in NPN, IPN, and EHN were calculated. From the finding that the calculated results of O--NO2 BDEs in NPN, IPN, and EHN are we!l coincident with the experimental results of apparent activation energies from ARC, we can draw a conclusion that the experimental thermolysis of three nitrates is only unimolecular homolytical cleavage of the O--NOz bonds.
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2009年第5期962-968,共7页
Journal of Atomic and Molecular Physics
基金
安徽省教育厅自然科学基金(KJ2008B009)
关键词
硝酸酯
加速量热仪(ARC)
反应风险指数
密度泛函理论
键离解能(BDE)
nitrates, Accelerating Rate Calorimetry （ARC）,, reactivity risk index （RRI）, density functional theory （DFT）, bond dissociation energy （BDE）
