Thermoanalysis includes methods for analyzing material properties or how they change over time or depending on the temperature. The different methods have a variety of potential applications.
Differential scanning calorimetry
Differential scanning calorimetry (DSC) is a technique that records the difference in the amount of heat required to increase the temperature of a sample and a reference material when consistently heated, cooled, or subjected to isothermal conditions. It can generally be used to determine the specific heat capacity, the glass transition temperature and the melting and crystallization temperature. On the basis of these metrics, you can glean information about the purity of your product.
Thermogravimetric analysis (TGA) determines the mass or mass change of a sample under inert or oxidative conditions (N2 or air). This makes it possible to observe the thermal stability of your product or oxidation and decomposition processes. The water content, impurities and composition of samples can be indirectly inferred based on this. One of the focuses of our company is characterizing polymer blends and pharmaceutical products.
Thermal analysis methods such as DSC and TGA can be used individually, simultaneously or even in combination with infrared spectroscopy.
High-temperature infrared spectroscopy
In high-temperature infrared spectroscopy, the samples are heated in a nitrogen atmosphere, and the escaping gases are passed through the measuring section of the spectrometer. The individual infrared spectra of the resulting gas phase are recorded and analyzed in relation to the temperature. In addition, the volume of the sample decomposition products can be quantified by correlating them with thermogravimetric results.
Hot stage microscopy
In comparison to conventional microscopy, hot stage microscopy makes it possible to determine the morphological profile of thermal transitions. Crystallization, melting and relaxation processes of semi-crystalline plastics, for example, can be observed in situ. Depending on the issue at hand, polarization contrast for optical microscopy or phase contrast for atomic force microscopy is available for this purpose.
Thermomechanical analysis (TMA) can be used to complement the methods mentioned above. A pressure-controlled penetration probe is placed on the sample. Dimensional changes can be measured when the sample is under inert conditions and subjected to a special temperature program. This makes it possible to make statements about the mechanical strength of a product, for example.