2-morpholineethanesulfonic acid, an important biological buffer. 2-morpholineethanesulfonic acid compounds can be used to prepare chromium-free passivation agent for manganese metal. 2-morpholineethanesulfonic acid compounds include 2-morpholineethanesulfonic acid, 2-morpholineethanesulfonic acid sodium salt, 2-morpholineethanesulfonic acid potassium salt, 2-morpholineethanesulfonic acid monohydrate, etc.

What role does it play in chromium-free passivation of manganese metal.

Manganese can significantly improve the mechanical properties of steel, increasing the strength, hardness and ductility of steel, and is an indispensable alloying element for steel production.

However, due to the low chemical potential and very high activity of manganese metal, it is easy to react with oxygen in the air and cause corrosion of manganese metal. The corrosion of manganese will not only greatly reduce the mechanical properties of manganese and shorten the service life of manganese machinery and equipment, but also destroy the electronic and optical properties of metal materials, and even cause catastrophic accidents and huge economic losses. Therefore, it must be passivated to improve the corrosion resistance of manganese.

This new environmentally friendly passivation agent includes straight-chain hydrophobic fatty acids, straight-chain fatty acid methyl ester sulfonates, soluble cerium salts and 2-morpholineethanesulfonic acid compounds, which have good passivation effect, environmental protection and good stability.

Among them, the 2-morpholine ethanesulfonic acid compound and the straight-chain fatty acid methyl ester sulfonate have certain pH buffering ability, especially the 2-morpholine ethanesulfonic acid compound has a buffer pH of 5.5-6.7, which can maintain the passivation agent in a weak acidic environment. The weak acidic environment can effectively slow down the hydrolysis of cerium salts, which can ensure the stability of the passivation agent and facilitate the formation of inorganic film layers.