Antioxidants are mainly used to protect substances from oxidative effects when exposed to oxygen, light, and/or heat. These oxidized items may change color, lose their original function, or produce harmful by-products due to exposure to air.
For example, the processing stability of fats (edible oils), polymer materials, and their intermediate products often requires the addition of appropriate amounts of fat soluble reducing antioxidants; The storage stability of many liquid polymer materials requires the addition of water dispersible free radical inhibitors. In addition, certain plastic products such as adipic acid resin also require the use of antioxidants in their production process to suppress degradation reactions.. The specific type of antioxidant to be selected depends on the properties of the material and the usage environment.
