The process of testing samples using thermogravimetric analysis is a highly accurate method to determine specific information about the physical and chemical changes in mass in a sample when there are controlled temperature changes over time.
The types of information that can be obtained by thermogravimetric analysis, more simply known as TGA, include the phase transitions of the sample, the absorption, and thermal decomposition as well as any reactions such as oxidation or reduction.
The Equipment
The equipment used in TGA is very specialized. It has the ability to provide a continuous measurement of the mass of the sample while precise temperature changes occur in the equipment over a period of time.
The equipment includes a balance that includes a sample pan that is in a chamber of the equipment. This chamber can be heated to extremely precise temperatures at a constant rate or determined for a constant mass loss.
This temperature change over time is set up for the specific sample to create a thermal reaction in the sample. This reaction can occur in a vacuum, which requires a sealed chamber, or in the presence of air or a specific type of gas or vapor. The pressure in the chamber can include constant pressures, high vacuums or high pressures.
The Reporting
The equipment used in thermogravimetric analysis provides a sophisticated report that is developed by the data from the specific analysis of the sample. This will be a plot type of report with the initial mass of the sample and then the changes in mass based on time and temperature.
It is possible to see the results of the testing using the actual points, or the plot can be smoothed to create a curve. This curve can be used to determine the performance of a range of different materials including elastomers, thermoplastics, thermosets, composites, films and even paints, fuels and coatings.
