稳定剂对DTBP热分解的影响

Effect of Stabilizer on DTBP Thermal Decomposition

采用热重分析仪(TG)和绝热加速量热仪(ARC)研究了过氧化二叔丁基(DTBP)与乙二醇、石蜡油和邻苯二甲酸二甲酯3种稳定剂混合后的热分解过程。实验结果表明:加入稳定剂后,DTBP的起始分解温度升高,反应最大温度、最大温升速率、最大压力和最大压升速率均有不同程度的下降。加入质量分数均为50%的3种稳定剂乙二醇、石蜡油和邻苯二甲酸二甲酯后,样品表观活化能由171.44 kJ/mol分别升高至201.79、235.08、229.11 kJ/mol,达到最大反应速率时间由78.76 min分别延长至122.05、197.79、141.48 min,表明稳定剂提高了DTBP自分解反应的难度,同时使DTBP在爆炸临界点前的时间延长。

Organic peroxides,which have been widely used as radical initiators in the production of resin,rubber,plastics,etc,tend to catch fire and explode at high temperatures.So far,it has been a common operation to utilize stabilizers to enhance the stability of peroxides.However,the research on the stabilization mechanism and performance of stabilizers are far from enough.Hence,in this paper,the thermal decomposition of di-tert-butyl peroxide(DTBP)was investigated with glycol,paraffin oil,or dimethyl phthalate as the stabilizers.With the adding of these stabilizers,the initial decomposition temperature of DTBP increased,while the maximum reaction temperature,the maximum rate of temperature rising,the maximum pressure and the maximum rate of pressure rising decreased to some extent.Their adiabatic decompositions are complex and their kinetic modeling approaches have to be comprehensive,as have been dealt within this work,to obtain reliable Arrhenius parameters.The initial decomposition temperature of DTBP increased,while the maximum reaction temperature,the maximum rate of temperature rising,the maximum pressure and the maximum rate of pressure rising decreased to some extent.The thermal decomposition of DTBP and its mixtures with stabilizers were proved to follow the first-order reaction kinetic mode,indicating that the rate of the decomposition was determined by the hemolytic scission of the-O-O-bond.Compared with that of pure DTBP,the activation energies for the thermal decomposition of the mixtures with stabilizers of glycol,paraffin oil,or dimethyl phthalate increased from 171.44 kJ/mol to 201.79,235.08,229.11 kJ/mol,respectively,reflecting the enhanced difficulty of the self-decomposition reaction of DTBP with the stabilizers.In addition,with the help of glycol,paraffin oil,dimethyl phthalate,the maximum decomposition reaction rate time extended from 78.76 min to 122.05,197.79,141.48 min,respectively,adding more than 40 min to the controllable time before the critical point of explosion.In conclusion,the decomposition process of DTBP can be slowed down obviously using ethylene glycol,paraffin oil or dimethyl phthalate as the stabilizers.