Thermal analysis is often used to determine the crystallization behavior of materials. Crystallization refers to the formation of crystal structures in a material, such as polymers or other organic and inorganic materials. Crystallization, as well as polymorphism, analysis can be performed with differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermomechanical analysis (TMA), and dynamic mechanical analysis (DMA). Hot stage microscopy or other optical techniques allow the visualization of crystal formation.
According to the International Confederation for Thermal Analysis and Calorimetry (ICTAC), thermal analysis is group of techniques in which a physical property of a substance is measured as a function of temperature while the substance is subjected to a controlled temperature program.
Differential scanning calorimetry is a thermal analysis technique that measures the heat flow into or out of a sample as it is heated or cooled. Differential scanning calorimetry can be used to determine the crystallization temperature and enthalpy of crystallization of a material. A DSC provides important information about a material's thermal behavior and crystal formation.
Thermogravimetric analysis is a technique that measures the change in weight of a sample as it is heated or cooled. When a TGA is equipped with thermocouples, it can be simultaneously used to study the crystallization behavior and decomposition of a material. A TGA/DSC can be used at temperatures up to 1600°C, therefore, high temperature crystallization behavior can also be measured.
TMA measures the dimensional changes of a material as a function of temperature, time, or force. During crystal formation, materials may undergo a change in volume due to the formation of crystal structures. TMA can detect these changes in volume and provide information about the degree and rate of crystallization.
Dynamic mechanical analysis is a technique that measures the mechanical properties of a material as a function of temperature, time, or frequency. Dynamic mechanical analysis is used to study the mechanical behavior of a material during crystallization and crystal formation, such as changes in stiffness, modulus, or damping.