Thermomechanical Analysis (TMA) is used to characterize the physical properties of materials when force is applied at specified temperatures and time periods. TMA is useful for investigating the properties of viscoelastic materials, such as organic polymers. A typical viscoelastic material generally changes its volume with ramping temperature. As the sample changes its structure, the probe moves around and measures the change in the sample's length. Subsequently, the measured length is correlated with other properties such as expansion, shrinkage, swelling, and softening.Hyphenation refers to the process of connecting two or more instruments together for the purpose of increasing the amount of information obtainable from a sample. Hyphenating thermogravimetric analyzers (TGA) with mass spectrometers (MS) and Fourier Transform Infrared (FTIR) spectrometers has a long history. The ability to combine spectroscopic data for the purpose of chemical analysis, with the mass loss data from the TGA has borne fruit over numerous material science fields.  For example, the pharmaceutical industry routinely monitors for the presence of solvent in their products.  Evolved gas analysis can provide information on degradation pathways, reaction products, and/or chemical composition.

In addition to MS and FTIR, the desire to hyphenate a TGA to GC-MS instruments is also of great interest to users.  But whereas MS and FTIR are continuous techniques (i.e. they continuously collect spectra during the execution of the TGA experiment), GC-MS is typically not continuous.  On the other hand, GC-MS will give the most complete chemical information about the evolved gas.