3. Macroscopic behavior of thermoplastics

3.1 Polymer response to stress

In general, the response of a polymer may depend on :

• temperature, which is a key parameter detailed elsewhere ;

• the speed of loading, which is of equivalent importance to temperature;

• the type of load: tension, compression or shear ;

• pressure (at least at high pressure);

• the level of deformation, since deformation leads to microstructural changes and therefore to changes in mechanical properties;

• thermomechanical history, i.e. any degradation during processing, and the microstructure induced by this history;

• ...