关键词: 热分解, 动力学, 自催化, 等温模型, 机理函数

Abstract: Bis 2,4-dichlorobenzoyl peroxide(DCBP)is usually used as an initiator,a hardener,and a vulcanizing agent in rubber industry.As a kind of organic peroxides,the peroxy group(-O-O-)may cause the thermal instability and explosion likelihood of DCBP.To analyze the potential hazards of its thermal decomposition,the differential scanning calorimetry(DSC)was used to test the thermal behavior of DCBP under dynamic and isothermal conditions.Kinetic parameters calculated by the Friedman iso-conversional method indicated the autocatalysis possibility of this decomposition.DSC curves obtained at five constant temperatures confirmed a strong autocatalytic reaction of DCBP.Exothermic onset temperature of DCBP was 98℃ and activation energy was between 232 kJ·mol^-1 and 236 kJ·mol^-1 under dynamic evaluation.When scanning at 92℃ in isothermal mode,the time to maximum rate was less than 30 min,so the best constant temperature for evaluation under this mode should be no higher than 92℃ to prevent loss of heat-flow signal.By simulating the five isothermal curves,a kinetic model was established and the mechanism function was found.As all data showed that reaction progress was short and reaction rate was high,it is best to avoid external heating and sudden energy transfer during DCBP manufacture,transportation and storage.Meanwhile,emergency rescue plans should be prepared for minimization of loss once accident happens.

Key words: thermal decomposition, kinetics, autocatalysis, isothermal model, mechanism function