过氧化二异丙苯的热动力学研究

采用同步热分析仪测定在不同升温速率下过氧二异丙苯(DCP)的热流和热失重数据,通过相关模型确定DCP的热动力学参数.热流曲线表明DCP先熔融再分解,熔点为39.5℃,吸热焓为110 J/g,放热峰温为165℃,分解热焓500 J/g;随着升温速率的增加,热分解温度参数出现热延滞,放热峰断面扩大;采用 Borchardt-Daniels方法确定DCP的活化能为140 kJ/mol,反应级数为1.热重曲线表明DCP为一阶段热失重,失重峰峰温为170℃,失重率近90%;随着升温速率的增加,热失重温度参数出现延滞,但失重率降低;采用非模型动力学方法确定DCP在转化率为0.3～0.9之间的表观活化能接近,其均值为102.8 kJ/mol.

Thermokinetic Studies of Dicumyl Peroxide

A synchronized thermal analyzer was used to measure heat-flow and weight-loss of dicumyl peroxide (DCP) at various heating rates. Numerical models of DCP thermo-kinetic pa-rameters were developed. The data show that DCP first fuses and then decomposes. The DCP melting point is 39.5℃ with an enthalpy for the phase transition of 110 J/g. The maximum temperature of decomposition is 165 ℃ with an enthalpy of 500 J/g. As the heating rate in-creased the temperature for the onset of decomposition shifted to higher temperatures. The thermal profile of the decomposition also extends to higher temperatures. The kinetic parame-ters for DCP decomposition were determined by the Borchardt-Daniels method. The reaction was first order and had an activation energy of 140 kJ/mol. The gravimetric curves show that the thermally induced weight loss occurs in one phase. The temperature of maximum weight loss is 170 ℃ and the total loss is about 90%. As the heating rate is increased the loss curve shifts to higher temperatures but the total weight loss becomes smaller. A model free kinetic method was used to calculate kinetic parameters from the weight loss curves. At a conversion of 0.3 to 0.9 the apparent activation energy is approximately constant with a mean value of 102.8 kJ/mol.