The degradation of polymers involves several chemical and physical processes accompanied by small structural changes, which lead to significant deterioration in useful properties of the polymeric materials. Degradation is an irreversible change, resembling the phenomenon of the metal corrosion. Degradation of the polymers is a very crucial aspect, which affects their performance in daily life. Throughout the life of a polymer, it encounters different kinds of degradation at various stages starting from the reactor where a polymer is synthesized, in extruder where it is processed, during service life and after its failure when it is discharged into the environment