Antioxidants prevent polymers from chemical oxidation (degradation) when exposed to external factors like heat, uv-light, air, water and shear stress.
They are also called heat stabilizers.
Not using antioxidants will cause changes to the chemical composition, processing problems during manufacturing, changes in the appearance and ultimately shortening of the life of the polymer.
Antioxidants interrupt the chemical oxidation process in different ways, according to their structure.
Antioxidants are soluble in oil and not in water.