TGA is used to determine the thermal properties and stability of materials under the influence of gradual heating over time which might result in state transformation and thermal degradation of the material via change in mass over time. It helps in identification and quantification of the content of materials within samples as low as milligrams.
The measurement parameters are temperature, time, weight, and their derivatives. Temperature of the furnace is controlled with a given heating rate of the sample and is vital to identify the changes in the sample during the temperature increase. There can be multiple methods in which cyclic heating and cooling of samples can be done depending on the type of analysis. These parameters are continuously monitored by the system in terms of both input and output.
Sample preparation:
The sample is placed on completely dried ceramic or aluminum pans and continuously purged with Nitrogen within the device. After the weight becomes stable, the initial weight is measured, and analysis is continued. The samples are usually weighed > 1 mg and can lead up to 15 mg depending on the density of the material and the quality of desired results. Higher amounts might lead to better results. The accurate heating range of samples is usually from 25 ℃ to 1000 ℃. It is important to note that the samples prepared must be free from any dissolved gases or absorbed humidity.
Typical TGA applications:
Applications of thermogravimetric methods are mainly concentrated in polymers research. Related applications may be listed as: