Thermomechanical analysis
Characterization of polymers by thermal analysis

Thermomechanical analysis (TMA) is a group of characterization methods used to measure dimensional variations in a sample under static stress. Variations in length or volume are recorded as a function of temperature, and the corresponding stress is either elongational or hydrostatic.

For volume measurements, the sample is placed in a liquid with a known coefficient of expansion. A piston is used to adjust the pressure and detect displacements. For low stresses, the instrument can measure the...