In order to perform the calculations in excel you will need to export the raw data as text files. You will then need to firstly calculate α (which is the degree or conversion or fraction converted) and convert temperature to K (if it is in °C) in excel for the TGA data obtained at each heating rate.

Dear Hamidah Jamil

Could you prove the file or at least the data for running in excel or in another program?

It could be an error of copy and paste or maybe relating with export the correct data (Did you calculate the degree conversion?).

With kind regards,

Julián Sánchez.

Hi Gunel T. Imanova and Julián E. Sánchez-Velandia this is example of my calculation, please have a look and comment. Thank you in advance

• Import the raw data into excel.
• Convert the y-axis from mass loss to degree of conversion (100-x)%.
• Now you have got a degree of conversion vs T data.
• Plot the data and fit in the set of models that are already available in the literature and see the best fit in order to comment on the mechanistic behavior of the reaction.
• Standard methods include the Kissinger method which can allow you to evaluate the activation energy and pre-exponential factor of the reaction.
• You can also perform model-free analysis (but that requires data at multiple heating rates).
• I hope this helps.

Dear Jamil,

I recommend the suggestions given by the other collaborators and suggest reading our articles for clarification regarding the equations and treatment of TG data for decomposition kinetics of lumefantrine drug.

MARQUES, Maria BF et al. Kinetics of lumefantrine thermal decomposition employing isoconversional models and artificial neural network. Journal of the Brazilian Chemical Society, v. 31, n. 3, p. 512-522, 2020.

CARVALHO, F. S. et al. Fractional kinetics on thermal analysis: application to lumefantrine thermal decomposition. Journal of Molecular Modeling, v. 26, n. 7, p. 1-9, 2020.

Hi Jamil,

I think the following like might help you:

https://excelcalculations.blogspot.com/2012/11/reaction-kinetics-excel.html

Dear Hamidah Jamil

I looked TGA data and your calculations. You need to have 3 or more various heating rates (for example, 5, 10 and 20 K/min) for further calculations. I recommend you read similiar research articles about thermal degradation kinetics.

1. Vyazovkin, S. et al. ICTAC Kinetics Committee recommendations for performing kinetic computations on thermal analysis data. Thermochimica Acta, 520, p. 1-19, 2011. doi:10.1016/j.tca.2011.03.034

2. Koga, N. Ozawa's kinetic method for analyzing thermoanalytical curves : History and theoretical fundamentals. Journal of Thermal Analysis and Calorimetry, 113, 3, p. 1527-1541, 2013. doi:10.1007/s10973-012-2882-5

3. Paik, P. , Kamal, K. K. Kinetics of thermal degradation and estimation of lifetime for polypropylene particles: Effects of particle size. Polymer Degradation and Stability, 93, 1, p. 24-35, 2008. doi:10.1016/j.polymdegradstab.2007.11.001

4. Das, P., Tiwari, P. Thermal degradation kinetics of plastics and model selection. Thermochimica Acta, 654, p. 191-202, 2017. doi:10.1016/j.tca.2017.06.001

Also, try different methods (Coats-Redfern, Kim-Park, Ozawa, Friedman and others) for your TGA data.

Hope, it will be helpful for you.