What is added to lubricants to prevent the formation of acids due to oil oxidation?

The addition of antioxidants to lubricants plays a crucial role in maintaining their performance and longevity. As oils oxidize, they can produce harmful byproducts, including acids, which can lead to corrosion and degradation of both the lubricant and the machinery it is meant to protect. Antioxidants effectively neutralize free radicals formed during oxidation, thereby slowing down or preventing the oxidation process and the associated formation of acids. This protective action helps to maintain the lubricant's chemical stability and performance, ensuring that it continues to reduce friction and wear in machinery components over time.

While detergent-dispersants help in keeping contaminants suspended and preventing deposits, viscosity index improvers assist in maintaining a consistent viscosity across a range of temperatures, and emulsion breakers are used to separate water from oil, none of these functions directly prevent the formation of acids resulting from oil oxidation. Therefore, antioxidants are essential for preserving the integrity and effectiveness of lubricants in various applications.