Antioxidants are essential products to maintain the normal operation of mechanical equipment!
With the rapid development of the industrial and automotive industries, lubricant additives and antioxidants play an increasingly important role in maintaining the normal operation of mechanical equipment.
Introduction to lubricating oil additives and antioxidants
In lubricants, antioxidants are used to prevent oxidation, a process in which molecules react with oxygen and break down over time. Oxidation can cause sludge, varnish or deposits to form in the lubrication system, compromising lubricant performance and causing equipment damage. This is particularly important in applications where the lubricant is subject to high temperatures, pressures or long-term use.
Lubricating oil additive antioxidant is a chemical substance that can improve the quality of lubricating oil. It can effectively delay the oxidation process of lubricating oil and extend the service life of mechanical equipment. Antioxidants inhibit the oxidation reaction of hydrocarbons in lubricating oil and prevent the formation of oxidation products, thereby reducing the acid value and viscosity of lubricating oil and ensuring the normal operation of mechanical equipment.
The Importance of Antioxidants in Lubricating Oils
Antioxidants in lubricants work by inhibiting the reaction between oxygen and the lubricant, thereby preventing a decrease in lubrication performance. They scavenge free radicals and inhibit the formation of oxidation products, helping to maintain the integrity of the lubricant and extend its service life.
Lubricating oil antioxidants are of great significance in maintaining the normal operation of mechanical equipment. As the operating time of mechanical equipment goes by, the lubricating oil will gradually undergo an oxidation reaction to generate viscous and acidic substances. These substances will reduce the lubricating effect of lubricating oil and even corrode mechanical equipment. Adding antioxidants can effectively delay the oxidation process of lubricating oil, extend the service life of mechanical equipment, and improve the working efficiency of mechanical equipment.
Common antioxidants and their functions
There are many types of antioxidants that can be used in lubricants, including phenols, amines, and hindered phenols. These antioxidants can be customized for specific lubricant formulations and applications based on factors such as operating conditions, base oil type and desired performance characteristics.
Phenolic antioxidants: Phenolic antioxidants can inhibit the oxidation reaction of hydrocarbons in lubricating oil and prevent the formation of oxidation products. At the same time, they also have good thermal stability and water resistance, which can effectively improve the anti-oxidation performance of lubricating oil.
Sulfur antioxidants: Sulfur antioxidants can combine with active substances in lubricating oil to form stable complexes, thereby slowing down the oxidation rate of lubricating oil. At the same time, they can also improve the high temperature resistance and anti-wear properties of lubricants.
Phosphorus antioxidants: Phosphorus antioxidants can combine with hydrocarbons in lubricating oil to form stable complexes, thereby preventing oxidation reactions from occurring. In addition, they improve the water and corrosion resistance of lubricants.
Choose the right antioxidants
Choosing the right antioxidant is crucial to improving lubricant quality and maintaining the normal operation of mechanical equipment. When choosing antioxidants, we need to consider the following factors:
Antioxidant activity: Antioxidant activity is an important indicator of its antioxidant effect. Generally speaking, antioxidants with higher activity can more effectively delay the oxidation process of lubricating oil.
Antioxidant Stability: Antioxidant stability refers to its ability to remain active in the lubricant. Some antioxidants lose activity under high temperature, high pressure or long-term storage conditions, so it is necessary to choose antioxidants with better stability.
Compatibility of antioxidants with other additives: Other additives are usually added to lubricating oils, such as anti-wear agents, detergents, etc. Therefore, when selecting an antioxidant, you need to consider its compatibility with other additives to ensure they can work together to improve the overall performance of the lubricant.
Safety of antioxidants: Some antioxidants contain harmful ingredients such as phenol. When choosing antioxidants, we need to pay attention to their safety and try to choose antioxidants that are harmless or have low toxicity.
When selecting a lubricant containing antioxidants, it is important to consider the specific requirements of the equipment and follow the manufacturer’s recommendations. This ensures that the lubricant provides adequate protection against oxidation and extends the service life of the equipment.
Lubricating oil additives and antioxidants are essential products to maintain the normal operation of mechanical equipment. By adding antioxidants, the oxidation process of lubricating oil can be effectively delayed and the antioxidant performance of lubricating oil can be improved. When selecting antioxidants, we need to consider factors such as their activity, stability, compatibility, and safety. The correct selection and use of antioxidants can effectively extend the service life of mechanical equipment and improve the working efficiency of mechanical equipment. What do you think about this?
🧪 What Are Antioxidants in Lubricants?
Antioxidants are chemical additives used in lubricating oils to prevent or slow down oxidation of the base oil. Oxidation is a major cause of oil degradation, especially at high temperatures, leading to:
- Sludge and varnish formation
- Thickening of oil
- Acid buildup (corrosion risk)
- Shortened oil life
✅ What Antioxidants Do:
| Function | How It Helps |
|---|---|
| Prevents oil thickening | Maintains viscosity over time |
| Inhibits sludge/varnish | Keeps engine parts cleaner |
| Reduces acid formation | Protects metal surfaces from corrosion |
| Extends oil life | Allows longer drain intervals |
| Improves thermal stability | Especially in high-temp applications |
🔬 Types of Antioxidants Used in Lubricants:
1. Primary Antioxidants (Free Radical Scavengers)
These react directly with free radicals to stop chain oxidation reactions.
- Phenolic Antioxidants
e.g., Butylated Hydroxy Toluene (BHT), Alkylated phenols
✔ Effective at low to medium temperatures - Aminic Antioxidants
e.g., Diphenylamine derivatives
✔ Very effective at high temperatures
2. Secondary Antioxidants (Peroxide Decomposers)
These decompose hydroperoxides before they break down into harmful radicals.
- Phosphites
e.g., Tris(nonylphenyl) phosphite
✔ Boost effectiveness of primary antioxidants - Sulfur-containing antioxidants
✔ Good thermal stability
🔥 Why They’re Critical in High-Performance Oils:
- Engine oils (especially synthetic) run hot and are exposed to oxygen and fuel combustion byproducts.
- Turbine, hydraulic, and industrial oils may be used continuously for thousands of hours.
- Without antioxidants, these oils would oxidize quickly, forming varnish, sludge, and acids.
🛢️ Antioxidants in Used Oil Analysis:
One way to track oil condition is to measure antioxidant depletion using tests like:
- RULER (Remaining Useful Life Evaluation Routine)
- FTIR oxidation index
- Differential Scanning Calorimetry (DSC)
⚠️ Note:
Antioxidants do not regenerate — once depleted, they’re gone. That’s why regular oil monitoring and replacement is important in high-demand systems.