2,4-二硝基甲苯热解自催化特性鉴别及其热解动力学

为研究2,4-二硝基甲苯(2,4-DNT)的热危险性及其分解反应的特征, 利用差示扫描量热仪(DSC)对该物质进行了动态扫描测试, 得到其起始分解温度T₀范围为272.4-303.5℃, 分解热ΔH_d约为2.22 kJ·g^-1. 在此基础上, 采用瑞士安全技术与保障研究所提出的快速鉴别法(瑞士方法)及数值模拟技术, 对其分解反应的特性参数进行了推算, 结果表明其分解具有自催化性. 采用Malek法分析了该物质分解反应的最概然机理函数并得出了相关动力学参数, 表明其分解具有自催化性且符合Sestak-Berggren 双参数自催化模型(SB模型), 这与瑞士方法所得结论一致. 采用等温DSC测试获得了该物质的‘钟形’热解曲线, 从而验证了两种方法的结论.

Identification and Thermokinetics of Autocatalytic Exothermic Decomposition of 2,4-Dinitrotoluene

The thermal stability and autocatalytic decomposition of 2,4-dinitrotoluene (2,4-DNT) is investigated under dynamic and isothermal conditions using differential scanning calorimetry (DSC). The temperature range of initial exothermic temperature (T₀) is 272.4-303.5℃, and its decomposition enthalpy (ΔH_d) is about 2.22 kJ·g^-1. An identification method based on a numerical simulation technique from the Swiss Institute for the Promotion of Safety and Security (Swiss method) is used to determine the characteristic parameters of the decomposition reaction, revealing that the decomposition of 2,4-DNT is potentially autocatalytic. The Malek method is used to determine the most probable mechanism function and kinetic parameters of 2,4-DNT decomposition. The Sestak-Berggren model with two parameters is suitable to describe the autocatalytic decomposition of 2,4-DNT, which is consistent with the results of the Swiss method and isothermal experimental results. Isothermal DSC experiments confirmed that the decomposition of 2,4-DNT is autocatalytic.