I work on modification of epoxy resin system with silicon nanoparticles. The concentration of nanoparticles varies (5,10,15 and 20%). I performed a TGA scan for all 4 samples at the same heating rate (10C/min).
Is it possibe to calculate the activation energy of degradation from those scans only? I am aware that Ea can be calculated from the slope of the plot (Kissinger and Ozawa method) if TGA is run at diffrent heating rates, but before I perform additional 12 experiments (which are expensive and time consuming) I would like to ask if there is any method/approxmiation that I can use to compare the thermal degradation of my samples with diffrent content of modifier (using a single heating rate scan only)?
Many thanks for all your suggestions!
No you need at least 3 consistent experiments with each concentration and heating rate to apply Kissinger and Ozawa method. Keep in mind that samples with nanoparticles should be homogeneous, else you get in-different results. Your 12 experiments will turn into 36 for averaging.
I published few papers on it, attached here for your help. Good luck.
Your TGA curves can give you a qualitative idea of how the kinetics change in the presence of various amounts of additives. For example, a more or less abrupt weight loss correspond to more of less fast decomposition. But for getting quantitative data, you need repeating the same at (at least) 3 different temperatures.
Alain
Dear Agnieszka,
Measuring the amount and rate of change in the weight of a material as a function of temperature or time in a controlled atmosphere is able to deliver you information about the kinetics of decomposition and in-use lifetime forecast.
There are different approaches mostly by constant heating with different rates. A special method for high-resolution TGA is reported by S. Sauerbrunn & P. Gill (TA Instruments) varying (slowing) the heating rate during decomposition regions.
Attached you will find more information with indications on reduction of number of experiments.
With best regards
Michael
No you need at least 3 consistent experiments with each concentration and heating rate to apply Kissinger and Ozawa method. Keep in mind that samples with nanoparticles should be homogeneous, else you get in-different results. Your 12 experiments will turn into 36 for averaging.
I published few papers on it, attached here for your help. Good luck.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles