In lubricating oils, antioxidant additives are essential components that stabilize performance and extend oil life. When the oil operates under high temperature and is exposed to oxygen, oxidation reactions occur rapidly. These reactions alter the oil’s structure, creating sludge, increasing viscosity, and reducing lubricity. To control this process, antioxidant additives are incorporated to protect the oil from chemical degradation. As a result, the mechanical system maintains stable and long-lasting performance.
THE IMPORTANCE OF ANTIOXIDANT ADDITIVES IN LUBRICANT OILS
Oxidation is a natural process that causes lubricating oils to age over time. Under the influence of heat, pressure, and metal catalysts, oil molecules break down and form free radicals. These radicals react with oxygen in a chain process, generating acids, resins, and sludge. Such byproducts darken the oil and diminish its lubricating properties. Antioxidant additives block this chain reaction, keeping the oil structure stable, protecting metal surfaces, and reducing wear. As a result, the oil retains its quality longer, ensuring smooth operation and lower maintenance costs.
WORKING MECHANISM OF ANTIOXIDANT ADDITIVES
Oil oxidation occurs in three stages: initiation, propagation, and termination. When heated, hydrocarbon molecules in the oil lose hydrogen atoms and form free radicals. These radicals react with oxygen to produce peroxy radicals, which accelerate the degradation process. Antioxidant additives act as “free radical scavengers.” They react with these radicals before they attack the oil, interrupting the oxidation chain and maintaining chemical stability. This mechanism slows acid formation, minimizes viscosity increase, and keeps the oil’s clarity consistent throughout its service cycle.
COMMON TYPES OF ANTIOXIDANT ADDITIVES
Phenolic antioxidants function in the early stage of oxidation. They donate hydrogen atoms to neutralize free radicals, helping stabilize the oil under moderate conditions. Aminic antioxidants perform better at higher temperatures, especially in engine and gear oils, thanks to their strong thermal stability and resistance to oxidation. In addition, ZDDP (Zinc Dialkyldithiophosphate) is a multifunctional additive that provides both antioxidant and anti-wear protection. It forms a protective film on metal surfaces, reducing friction and preventing sludge formation. The combination of these three types offers optimal oxidation stability and extends oil life.
STANDARDS FOR EVALUATING ANTIOXIDANT EFFECTIVENESS
The effectiveness of antioxidant additives is determined through international testing standards. The most common is ASTM D943 (Turbine Oil Oxidation Stability Test), which measures the oxidation stability of turbine oils in the presence of water and metal catalysts. ASTM D2272 (RPVOT – Rotating Pressure Vessel Oxidation Test) evaluates the oil’s resistance to oxidation under high temperature and pressure. ASTM D2893 determines viscosity change after accelerated oxidation. Higher test results indicate stronger antioxidant protection, leading to extended oil life and reduced premature aging.
VICHEM – OFFICIAL DISTRIBUTOR OF MINGLAN LUBRICANT ADDITIVES IN VIETNAM
Vichem is the authorized distributor of Minglan lubricant additives in Vietnam, fully compliant with local legal regulations. We not only provide high-quality products but also deliver international-standard after-sales services. Our services include:
- Technical consulting: Supporting customers in selecting the right additive for specific applications.
- Color testing: Vichem’s experts conduct color and compatibility tests to ensure results meet production requirements.
- Application support: Collaborating with clients during system integration to ensure optimal performance and consistent quality.
For more information about our products, please contact us via:
📞 Hotline: 08 1790 1790
📧 Email: contact@vichem.vn
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🌐 Website: www.vichem.vn
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