Differential scanning calorimetry (DSC): thermal analysis of materials and polymers
Differential scanning calorimetry (DSC) is a thermal analysis method used to measure enthalpy changes associated with physical or chemical transitions in a material as a function of temperature. Accurate, rapid, and non-destructive, DSC is essential for studying thermal stability, transition temperatures, formulation compatibility, and exothermic and endothermic reactions. It is widely used in the polymer, pharmaceutical, cosmetic, materials, and food industries.
What is differential scanning calorimetry?
Differential scanning calorimetry (DSC) is a thermal analysis technique used to measure the amount of heat absorbed or released by a material when subjected to a controlled temperature program .
The principle is based on comparing the heat flow between a sample and an inert reference. Every thermal transition (melting, crystallization, polymerization, degradation, etc.) induces a change in enthalpy, detected as endothermic or exothermic peaks on a thermogram.
What analyses can be performed with DSC?
Identification of thermal transitions: temperature (Tf) , glass transition (Tg) , crystallization , etc.
Thermal stability analysis: thermal degradation or oxidation temperatures .
Formulation compatibility study: verification of the interaction between an active ingredient and an excipient (pharmaceutical or cosmetic formulation).
Polymer quality control: identification of amorphous/crystalline structure , degree of crystallinity, detection of manufacturing defects.
Measurement of heat capacity (Cp) : useful in materials development, thermal calculations, or simulation of thermomechanical behaviors.
Quantification of substance purity: by analysis of the melting profile and calculation of enthalpy.
How the DSC method works
The operation of a differential scanning calorimeter is based on the following steps:
- Sample and reference preparation : the sample (a few milligrams) is placed in a sealed cell, compared to an empty cell or one containing an inert reference.
- Controlled thermal sweep : the temperature increases or decreases according to a predefined gradient (usually between -100 °C and +600 °C).
- Heat flux detection : any thermal reaction results in a difference in flux detected and recorded in mW.
- Interpretation of the thermogram : the peaks obtained allow us to determine the transition temperatures, the enthalpy of the reactions and the nature of the transformations.
Technical specifications of the DSC
- Temperature range : typically from -100 °C to +600 °C
- Possible atmospheres : inert (nitrogen, argon), oxidizing (air)
- Thermal resolution : high sensitivity for detecting weak transitions
- Measured parameters : transition temperature, enthalpy (J/g), heat capacity (Cp), degree of crystallinity
- Related standards : ISO 11357 (1 to 7), Pharmacopoeias (Ph. Eur., USP)
For which matrices?
Differential scanning calorimetry is applicable to many types of materials, including:
Main industrial applications
paragraph paragraph paragraph
Léa Géréec
Technical and scientific expert
