AN208 – Thermal stability study by SENSYS DSC : influence of pressure on the thermal stability of azodicarbonamide

INTRODUCTION

Azodicarbonamide formula is NH2 – CO – N = N – CO – NH2. The compound belongs to the family of azo dyes. Azodicarbonamide decomposes at about 200°C. But the decomposition phenomena largely depends on the pressure above the sample. Different tests are run in an open crucible, a sealed crucible and a controlled high pressure crucible, in order to show that the pressure on the sample has a great influence on the decomposition rate.

AN-208

EXPERIMENTAL

Sample : Azodicarbonamide
Mass : 3.0 mg
Crucible :        – Sealed stainless steel
– Alumina (open)
– Controlled HP crucible
Heating mode : 5 K.min-1.

CONCLUSION

Azodicarbonamide, when heated in an open crucible, is weakly decomposed at about 500 K, before evaporating. In a sealed crucible, the decomposition phenomena is much more violent, and no more vaporisation is detected. When using the controlled HP crucible (pressure = 20 bars), the decomposition rate is modified and becomes very high.