I PerkinElmer DSC 8000
Differential scanning calorimetry is an important technique in determining the phase transitions such as melting, crystallization, crystal to crystal transitions, crystal to liquid crystal, and vice versa, glass transactions in polymers, etc. It gives valuable information on heat absorbed or released during phase change.
- Differential scanning calorimetry can be used to measure a number of characteristic properties of a sample. Using this technique it is possible to observe fusion and crystallization events as well as glass transition temperatures.
- DSC can also be used to study oxidation, as well as other chemical reactions
- Glass transitions may occur as the temperature of an amorphous solid is increased. These transitions appear as a step in the baseline of the recorded DSC signal. This is due to the sample undergoing a change in heat capacity; no formal phase change occurs.
- As the temperature increases, an amorphous solid will become less viscous. At some point, the molecules may obtain enough freedom of motion to spontaneously arrange themselves into a crystalline form. This is known as the crystallization temperature (Tc). This transition from amorphous solid to crystalline solid is an exothermic process and results in a peak in the DSC signal. As the temperature increases, the sample eventually reaches its melting temperature (Tm). The melting process results in an endothermic peak in the DSC curve. The ability to determine transition temperatures and enthalpies makes DSC a valuable tool in producing phase diagrams for various chemical systems.