Oxidation Inhibitor
Oxidation inhibitor is a chemical additive used to slow down or prevent oxidation, a chemical reaction where substances lose electrons, often in the presence of oxygen. Oxidation can lead to deterioration, especially in materials and fluids exposed to heat, air, or light, such as oils, lubricants, fuels, and polymers.
Key Points about an Oxidation Inhibitors
Prevent Degradation - They help maintain the integrity of materials by preventing chemical changes that lead to breakdown.
For example, in lubricants, oxidation inhibitors prevent oil thickening and formation of sludge.
Extend Product Life - In fuels, oxidation inhibitors reduce the formation of gum and deposits, thereby enhancing fuel stability and extending its usable life.
Improve Performance - They help maintain efficiency in machinery and systems by keeping lubricants, fuels, and other fluids stable over time, which reduces maintenance needs.
The process of oxidation occurs in three stages
Stage 1 - Lubricant and fuel react with oxygen to form radicals.
Stage 2 - Radicals react with oxygen and the lubricant to form hydroperoxides.
Stage 3 - The hydroperoxides decompose to form a variety of additional radicals
Oxidation Inhibitors Types
Anodic Inhibitors (Passivating Inhibitors) - These inhibitors function by producing a protective oxide layer on the metal surface, preventing oxidation and reducing exposure to corrosive substances. By increasing the corrosion potential, anodic inhibitors drive the metal into a passive state, making it less reactive and more resistant to corrosion.
Cathodic Inhibitors - This inhibitor work by obstructing the cathodic reaction, which normally entails the reduction of oxygen or hydrogen ions in a corrosive environment. Cathodic inhibitors stop this process from happening, which lowers the metal's overall propensity to lose electrons and stops chemical deterioration.
Mixed Inhibitors - By mixing anodic and cathodic inhibitors, mixed inhibitors efficiently reduce both types of corrosion causing processes and offer dual protection. Typical combined inhibitors, including silicate compounds and organic amines, create a protective film that covers the whole metal surface and provides complete corrosion resistance.
Volatile Corrosion Inhibitors - These inhibitors shield metal surfaces by releasing vapors into the atmosphere, which subsequently cover the metal in a thin layer of molecules. The metal is shielded from the environment's corrosive substances and moisture by this layer of protection.
Organic Inhibitors - In acidic settings, such as those found in the oil and gas sectors, where metals must withstand hostile conditions during the drilling and refining processes, organic corrosion inhibitors are mainly employed. These inhibitors attach themselves to the metal surface as atoms of nitrogen, oxygen, or sulfur, creating a barrier that keeps out corrosive attacks.
Inorganic Inhibitors - Metal salts, which coat or mask the metal surface to aid in passivation or react with corrosive species in the environment to neutralize them, are the main component of inorganic inhibitors. Silicates, phosphates, and chromates are common chemical compounds that are employed as inorganic inhibitors because they work well in both neutral and acidic media.
Precipitation Inhibitors - The mechanism by which precipitation inhibitors work is to build insoluble compounds that cover metal surfaces in corroding environments, providing a protective layer. These inhibitors' main ingredients, magnesium hydroxide and calcium carbonate, efficiently coat the metal in aqueous settings.
Chelating Inhibitors - Chelating inhibitors, also known as sequestering agents, function by forming stable complexes with metal ions present in a corrosive environment, thereby preventing these ions from reacting with other corrosive species. This chelation process helps to minimize the rate of corrosion by keeping metal ions in a water-soluble form, which reduces their reactivity.
Film-Forming Inhibitors - Inhibitors of film formation work by covering the metal surface with a thin layer of protection that keeps corrosive substances from coming into direct contact with the metal. The majority of these inhibitors are organic substances that attach themselves to the surface of the metal to create a barrier that strengthens corrosion resistance. Fatty acids, esters, and amides are common examples of film-forming inhibitors; they are a part of an inhibitory series that successfully lowers corrosion rates.
Oxidizing Inhibitors - These inhibitors work by encouraging the development of a stable oxide layer to shield metal surfaces from corrosion. These inhibitors include substances that catalyze oxidation processes that would normally happen more slowly, such as chromates and nitrates.
