2. Oxidation

2.1 The role of oxygen

Ionizing radiation irradiation in an inert atmosphere can lead to significant structural changes in polymers within a relatively short time, generally as an inverse function of the dose rate. Some of these modifications can be favorable, for example, the radiation cross-linking of PE is used industrially to improve certain thermomechanical properties of this polymer.

In the absence of ionizing radiation, most industrial polymers are virtually infinitely stable in an inert atmosphere, at the temperatures at which they are usable (and even for most transformable), whether or not they are irradiated with UV of λ ≥ 300 nm.

The presence of oxygen totally changes the picture for one main reason: oxidation reactions...