Study On Thermal Decomposition Characteristics Of Organic Peroxides

Organic peroxides belong to the category5hazardous chemical. There have been many incidents during their storage, transport and use. To study thermal stability of this kind of material and give reliable technical parameters to the user, the thermal decomposition characteristics were discussed based on research results of thermaldynamics and dynamics of peroxides’thermal decompositions. By use of Differential Scanning Calorimeter (DSC) and Accelerating Rate Calorimeter (ARC), the thermal decomposition tests of three MEKP solutions and three kinds of organic peroxides’chemical pure including MEKP, TBPB and DHBP were conducted. By use of AKTS to conduct thermaldynamics and dynamics analysis of DSC datas, the thermal decomposition process of the samples and the risk size of their thermal decompositions were decided based on the analysis results. By means of related dynamics theory to analyze ARC test results, TMRad (Time to Maximum Rate under adiabatic) of the test samples’decomposition reaction was calculated. With the help of Semenov thermal explosion model, the SADT (Self-Accelerating Decomposition Temperature) was obtained. The experimental results show that:from DSC test results, there are two steps during MEKP’s decomposition. The addition of dilution stabilizer can reduce Q and separate the two exothermic peaks. The same sample’s activiation energys from Friedman method, Ozawa Method and ASTM E698method have good consistency. Decomposition of MEKP under adiabatic has more serious consiquences. Meanwhile, there are gas products generated during its decomposition. Thus, the pressure effect should be considered under closed system. Inaddition to reduce Q and△Tad (adiabatic temperature rise), dilution stabilizer can also lengthen TMRad and increase SADT. Thus, dilution stabilizer makes MEKP solutions more stable than pure ones. Both size orders of three peroxides’ TMRad and thermal stability which was decided based on SADT are DHBP>TBPB>MEKP. Based on the analysis above, the risk assessment results of the peroxides’thermal runaway decomposition in chemical process fell in the "ALARP erea" or higher in the risk matrix. It shows that measures must be taken to control desired reaction strictly, and the process should be changed when necessary.