2. Dynamic surface appearance

2.1 Characteristic temperatures and behavior

For an amorphous polymer, the main characteristic temperature is the glass transition temperatureT _g , which is due to the freezing of the movement of an entire molecule (diffusion of the molecule of an amorphous polymer) or the mobility of the entire molecular segment between crystalline lamellae. At lower temperatures, shorter segment movements allow either a return to thermodynamic equilibrium or "physical aging".

The main transition in semi-crystalline polymers is crystal melting. The melting temperature depends on the thickness ℓ of the crystals and therefore on the crystallization conditions. The (absolute) melting temperatureT _m ...