The effect of the reaction heat on kinetic analysis by TG under a rising temperature program. Part 2

Abstract

In Part 1 (Thermochim. Acta, 215 (1993) 83-95), the effect of reaction heat changes upon the rising temperature program was accounted for by using a relationship between a sample's temperature T and time t as a function of the degree of conversion α. The simulation and the kinetic analysis was made for the extreme situation of the temperature recorded by thermocouple being exactly the same as that of the sample. In the present study, another extreme case is considered, that the temperature recorded by the thermocouple is exactly the same as that of the furnace. On this assumption, a simulation of TG, DTG and T-t curves under both such a temperature program and the ideal rising temperature program was made, showing how the reaction heat affects these curves. As before, a kinetic analysis can be achieved for the calculation of the Arrhenius parameters, and the determination of the reaction mechanisms performed, by using integral or differential methods. The data obtained show that the kinetic parameters and the reaction mechanism are all changed to some extent by the effect of the reaction heat.