Abstract:

An accurate thermal decomposition model helps people take measures of prevention and controlling the burning and explosion accidents, which are caused by thermal run away of materials. This paper mainly studied a sample: 40%DCP solution (dicumyl peroxide dissolved in 2,2,4-trimethyl-1,3-pentanediol diisobutyrate). Experiments were performed with two devices, differential scanning calorimeter (DSC) and vent sizing package 2 (VSP2), analyzed the kinetics by TSS (Thermal Safety Software) and established two decomposition models: model 1 “N-order followed with N-order” and model 2 “N-order followed with autocatalysis”, then, the kinetic parameters were estimated by Friedman method and non-linear simulation method. From simulated curves, both models described the decomposition curve for dynamic calorimetry mode or adiabatic calorimetry mode well, which illustrated the limitation of kinetics study for single calorimetric mode. Therefore, paper proposed a method that estimated the parameters based on both dynamic calorimetry mode and adiabatic calorimetry mode decomposition curves, found that only model 1 explained the decomposition well. Therefore, 40%DCP decomposition can be expressed as model 1, in which the activation energy for two steps are 115.5 kJ·mol^-1 and 135.7 kJ·mol^-1, the natural logarithm of pro-exponential factor are 28.3 and 31.6, and reaction order are 0.40 and 0.84. This study proved that estimation of kinetic parameters with two different calorimetry modes can help determine right kinetic model, obtain accurate kinetic parameters, and overcome the limitation of kinetics study with single calorimetric mode.

Key words: thermal decomposition, calorimetry mode, 40%DCP solution, kinetics, decomposition model

摘要：

准确的热分解动力学模型有助于人们采取各种安全措施预防和控制物料热失控导致的燃烧爆炸事故。以40%过氧化二异丙苯（DCP）的2，2，4-三甲基戊二醇二异丁酯（DIB）溶液为研究对象，运用差示扫描量热仪（DSC）和绝热量热设备（VSP2）进行了量热实验，并采用TSS软件（Thermal Safety Software）对数据进行动力学分析，建立了两种分解模型：“N级+N级”模型（模型1）和“N级+自催化”模型（模型2），采用Friedman法和非线性拟合方法求算其动力学参数。在运用所建立的两种模型拟合曲线时，发现两种模型对同种量热模式数据拟合的相关系数非常接近，说明单一量热模式在求算动力学上存在局限性。联合采用基于动态扫描模式的DSC数据及基于绝热模式的VSP2数据共同求算动力学，发现相对于模型2，模型1可以更好地反映分解过程，其两步反应的活化能分别为115.5 kJ·mol^-1和135.7 kJ·mol^-1，指前因子的对数分别为28.3和31.6，反应级数分别为0.40和0.84。研究结果表明采用基于不同量热模式的数据求算动力学有助于确定正确的动力学模型，从而获得准确的动力学参数，并克服单一量热模式下动力学求算的局限性。

关键词: 热分解, 量热模式, 40%DCP溶液, 动力学, 分解模型