Differential Scanning Calorimetry (DSC)
Differential scanning calorimetry (DSC) measures the heat flow from a sample as a function of temperature or time. Differences in heat flow arise when a sample absorbs or releases heat due to thermal effects such as melting, crystallization, chemical reactions, polymorphic transitions, vaporization etc. DSC is also employed as the first in line analytical method for thermal safety analysis and can be used to rapidly assess whether molecules or mixtures are potentially highly energetic, shock sensitive, or explosive.
Melting, Crystallization, Evaporation
- Rapid determination of phase transitions such as melting point, glass transitions, crystallization, vaporization, degradation.
- Suitable for solids and liquids.
- High pressure pans also available
- Temperature range RT to 700 °C
- Maximum heating rate 300 K/min
Polymorphs
- Identification of polymorphs by melting point
- Crystallisation of API from various solvents followed by DSC analysis
Thermal Safety Evaluation
- Thermal safety profiling can be conducted using the DSC to determine the onset of degradation of a chemical or mixture and also to estimate the TD24 – the process temperature at which time to maximum reaction rate under adiabatic conditions is 24 hours.
Thermal Safety Evaluation of Glycidyl Nosylate
Further thermal risk can be conducted to give a more in-depth analysis. In this case, the use of glycidyl nosylate on large scale was restricted due to its “High Hazard” concern.
Typical DSC Thermogram
A thermogram generated for chemical compound “glycidyl nosylate”. Note the melting point at 64°C and the onset of degradation at 235°C. The thermogram shows a highly energetic decomposition at elevated temperatures.
