Polymer degradation:
Polymer degradation is a phenomenon due to which the properties of a polymeric material are deteriorated. It involves the uncontrolled change in molecular weight of constitution of polymer.
A polymer can suffer degradation at two stages of its life-
1/ During the fabrication process.
2/ During its daily usage.
1/ Fabrication stage:
Many of the fabrication process such as extrusion or moulding involve heating, which the polymer may not be able to endure and as consequence may just degrade.
2/ During daily usage:
In the hustle bustle of modern life plastic articles have to face mechanical, stress, solar radiations, atmospheric oxygen, etc and this can degrade the polymer.
Importance of polymeric degradation:
While polymer degradation is generally undesirable, it can sometimes be put to advantage as for example, when a spacecraft re-enters the earth atmosphere, intense heat is generated. Which is sufficient to melt the metal & even make the spacecraft explode. To avoid such a situation, the spacecraft is covered by heat shield, which is a polymer based material. As the heat shield encounters a high temperature on re-entry, the material chars & degrades & in the process takes away the severe heat & thus protects the spacecrafts.