Industry Antioxidant Definition & Classification
What Is Antioxidant? (Definition of Antioxidant)
Antioxidant is a chemical compound that prevents oxygen from reacting with other compounds that are susceptible to oxidation. Polymer antioxidant, is a class of heat stabilizers, can be added to improve the shelf life of the product or to improve its high-temperature stability. While adding a stability margin during thermal processing.
Classified by Mechanism
Antioxidants can be divided into two classes, according to their mechanism in interrupting the degradation process: (a) chain-terminating primary anti-oxidants, and (b) hydroperoxide-decomposing secondary antioxidants
Primary Antioxidant react rapidly and are termed “radical scavengers'”.The most important are sterically hindered phenolics and secondary aromatic amines.Hindered phenolics are high molecular weight anti-oxidants for polymer systems that are sensitive to thermal and oxidative degradation, due to the formation of free radicals and peroxides. They protect against degradation at high processing temperatures and are highly efficient, low in volatility, and non-staining, with wide toxicological clearance and are effective at very low dosages (0.01-0.1%).
Secondary Antioxidant reacts with hydroperoxides to produce non-radical products and is therefore often termed ‘hydroperoxide decomposers’. They differ from primary phenols and amines in that they are decomposed by reaction with a hydroperoxide, rather than containing it. They are particularly useful in synergistic combinations with primary anti-oxidants. Phosphite/phosphonites are generally regarded as the secondary antioxidant.
Antioxidant Binary Blends, primary antioxidants plus a high-temperature hydrolytically stable organo-phosphite secondary antioxidant or thioesters plus phenolic antioxidant, Their use is limited to applications where possible effects on odor or taste and negative interaction with HALS (hindered amine light stabilizers) are not important.
Classification by Chemistry
Industrial Antioxidant additives also classified into phenolics, metal deactivates, amines, phosphites, thioesters and binary blends among the industry.
Classification by Application
Industrial Antioxidant can apply in plastics, synthetic fibers, elastomers, adhesives, tackifier resins, and waxes.