Dear researchers,
please help me out in the following situation. I need to do TGA analysis of PUF (composition is castor oil/tdi/peg). The foam contains pure castor oil, which means that there is a small amount of non-polymerized fatty acids. Despite this, TGA analysis of castor oil foams has been often described in the publications. Typically analysis is conducted under inert atmosphere, in my case only nitrogen is available. Heating rate is 10 C/min, temp. range room -600 C, sample mass approx 5 mg. I got one sample done for me and analysis caused a lot of contamination and device shut down. Please correct me, how should I avoid contamination? I have expected volatile products to be produced, because it is the way test is done. But how to get rid of them inside the cell?
Thank you!
I can consider this problem with my colleagues who are working and have great experience with thermal analyses-but for now, have you considered to do your analyses in other type of instruments (i.e. other configurations). Some configurations are more suitable for working with liquids and samples that changes significantly during heating.
Hello dear. It can ressolve the issue so: You have to make the analysis by using nitrogen from room temperature until 600 Celcius degrees. Then you can use air from 600 to 800 or 900 Celcius degree.
You can used this program:
Gas 1 (nitrogen)
Heating Ramp 10 0r 20 Celcius degree/minute
Until 600 Celcius degree.
Gas 2 (air)
Heating ramp the same that before,
until 900 Celcius degree.
Best regards
Dear Edwin,
thank you very much for your suggestions!
I have ordered analysis in the other university's lab, they had only Ar.
They conducted the analysis for me only between room - 500 Celcius degrees (from publications I learned that at this temperature the foam is almost completely decomposed). Even the first run was not completed because of vast contamination. I want to understand the following: can low purge gas rate be the reason of experiment failure (50 ml/min)? Or I should blame the sample/wrong purge gas type?
Kindly give me your considerations regarding this.
I really appreciate your help!
Hello dear if you make the analysis only using nitrogen, when you finish the analysis appear a residue (sharp) but if it is performed by using aire atmosphere, the residue will dissapear.
The purgue gas rate only will afect the result if you need oxidative atmosphere and the air amount is not enough to decompose your sample.
Best regards
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