Estimation of TD24 from One Dynamic DSC Experiment

A simplified procedure may also be used as a rule of thumb. Its principle is as follows If the detection limit of an instrument working in the dynamic mode under defined conditions is known, then at the beginning of the peak, the conversion is close to zero and the heat release rate is equal to the detection limit, that is, the temperature at which the thermal signal differs from the signal noise. Thus, the detection limit can serve as a reference point in the Arrhenius diagram. By assuming activation energy and zero-order kinetics, the heat release rate may be calculated for other temperatures. 

Worked Example 11.1 TMRad and T,m from Isothermal DSC Experiments 

If we want to estimate the TMRad of the decomposition characterized above, at a lower temperature, for example, 120 °C, we can extrapolate the heat release rate as a function of temperature from 170 °C to 120 °C by using the calculated activation energy in Equation 11.3  

From the specific heat release rate of 2.9 Wkg at 120°C, and with a specific heat capacity of 1.8 kj kg-1 IC1, the TMRld can be calculated for this temperature using Equation 11.4  

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