5: Differential Scanning Calorimetry

Differential scanning calorimetry (DSC) is probably the most popular of the thermal analysis techniques if judged by the number of instruments sold and in use. This is a result of its wide range of application areas and also the fact that measurements are quick to make. DSC heats or cools a material in a controlled manner and measures the flow of energy into or out of the material whilst it does so. This reveals all of the transitions that occur within the material over the temperature range observed, together with the temperatures at which they occur. The most obvious transitions recorded are melting or re-crystallisation, but many smaller, much more sensitive events are also revealed, such as the glass transition (T_g). If appropriate methods are applied then the heat capacity (C_P) of a material can be obtained and reported. This chapter considers the theory of DSC instruments, gives aspects of good experimental practice and reviews briefly the main areas of application.