Oxidizers and catalysts are widely used in medicines and pesticides production. 2,2,6,6-tetramethylpiperidinyloxy(CAS:2564-83-2), commonly known as TEMPO, can be used both ways, and it has excellent stability in storage condition.
Following is chemical properties of TEMPO:
Appearance: red crystal
Molecular Weight:156.25
Melting Point: 36-38℃
Flashing Point: 67.8℃
Boiling Point: 193℃
Vapor pressure: 0.4hPa (20°C)
As we can see, melting point of TEMPO is relatively low and close to air temperature. Therefore, it may be partly melted when store in room temperature or during transportation. In this condition, stability of this compound become significantly important.
We have implemented the stability test of TEMPO in our lab. We took 100G of TEMPO sample and sealed in a fluorinated bottle, then put the bottle in a constant temperature oven, set the temperature to 40℃.Take samples and do the quality analysis every 2-3 days for a month. Following is the brief record of our stability test.
Time period: April 14, 2021- May 14, 2021
Purity test method: Gas chromatography
Moisture test method: Karl Fischer method
Ash content test method: Residue on ignition check method
Experimental apparatus: Electronic balance, Meteorological chromatograph, Karl Fischer micro moisture tester, Box type resistance furnace, Constant temperature oven, etc.
Test Time | Appearance | Purity | Moisture | Ash Content |
2021-04-14 | Red liquid | 99.75% | 0.56% | 0.05% |
2021-04-16 | Red liquid | 99.72% | 0.60% | 0.06% |
2021-04-18 | Red liquid | 99.75% | 0.55% | 0.05% |
2021-04-20 | Red liquid | 99.69% | 0.62% | 0.05% |
2021-04-22 | Red liquid | 99.65% | 0.58% | 0.06% |
2021-04-25 | Red liquid | 99.75% | 0.53% | 0.05% |
2021-04-27 | Red liquid | 99.76% | 0.53% | 0.05% |
2021-04-30 | Red liquid | 99.76% | 0.55% | 0.05% |
2021-05-01 | Red liquid | 99.66% | 0.55% | 0.04% |
2021-05-04 | Red liquid | 99.71% | 0.57% | 0.05% |
2021-05-06 | Red liquid | 99.71% | 0.57% | 0.05% |
2021-05-07 | Red liquid | 99.73% | 0.52% | 0.04% |
2021-05-09 | Red liquid | 99.71% | 0.59% | 0.04% |
2021-05-12 | Red liquid | 99.75% | 0.56% | 0.05% |
2021-05-14 | Red liquid | 99.72% | 0.59% | 0.04% |
This test has shown that TEMPO has excellent stability and can be stored in room temperature and transported for quite a long time.