Thermal Analysis is the generic name for a series of measurement techniques traditionally used to determine changes in material properties with temperature. Common thermal analysis techniques include:

- Differential Scanning Calorimetry (DSC) - is the most widely used thermal analysis technique. DSC measures the heat flow in materials and provides information about phase changes (amorphous and crystalline transitions) as well as chemical changes (degradation and reactions).

- Thermogravimetric Analysis (TGA) - measures weight changes associated with thermal events. While TGA is most commonly used to determine compositional analysis, it is also valuable for determining thermal stability. Furthermore, by analyzing multiple TGA curves obtained under different heating rates, it is possible to predict long-term as well as short-term thermal stability.

- Dynamic Mechanical Analysis (DMA) - measures the storage or elastic modulus and the loss or viscous modulus of materials subjected to sinusoidal or static stresses.

- Dielectric Analysis (DEA) - is the electrical analog of DMA in which the current (phase and magnitude) resulting from a sinusoidally imposed voltage are measured. Because mechanical and electrical properties are highly sensitive to small changes in material internal structures, DMA and DEA are more sensitive to low energy transitions, such as the glass transitions of filled epoxy systems, than are other thermal analysis methods. The static stress modes of the DMA further allow long term strength forecasts to be made using the creep or stress relaxation methods at elevated temperatures.

In this paper, the short-term and long-term physical properties of two engineering thermoplastics are explored. The results illustrate the value of thermal analysis for characterizing thermoplastic materials.