Morpholine as Metal Corrosion Inhibitor
2019-05-24
The application of morpholine as a metal corrosion inhibitor has the following aspects: (1) Used as a metal gas rust inhibitor. As a metal gas rust inhibitor, morpholine is widely used in mechanical instruments, automobiles, medical equipment and other fields to prevent metal from being corroded by the atmosphere. The metal atmospheric rust inhibitors dicyclohexylamine nitrite and cyclohexylamine carbonate used at home and abroad are highly toxic to humans and the environment, which restricts the promotion and application of gas phase rust inhibitors. As a metal vapor liquid corrosion inhibitor, morpholine has low toxicity and good development prospects. (2) Boiler and water circulation system. Morpholine has similar properties to secondary amines, is weakly alkaline, neutralizes carbonic acid in acidic aqueous solutions, and is widely used as a corrosion inhibitor for boilers and other water recycling systems. The morpholine state of any of the medium and high pressure systems remains stable. The vapor pressure of morpholine is similar to that of water and can be dissolved in water arbitrarily, so the system can maintain a constant ph. morpholine is often used with other amines to solve specific corrosion problems. (3) Used as an antiseptic additive. In lubricating oils, paints, metal cleaners, paint strippers and 1,1,1-trichloroethane, a certain amount of morpholine or morpholine derivatives are often added as corrosion inhibitors, such as N, N-polysulfide. Dimorpholine, N,N-cycloalkyldimorpholine and poly(4-morpholinomethyl)phenol. It can effectively prevent corrosion of running equipment parts. At the same time, it can also be used as an antioxidant for lubricating oils. The addition of N-tert-butylthiomorpholine or petroleum sulfonic acid morpholine as a corrosion inhibitor to petroleum storage tanks, pipes and distillation equipment can effectively prevent corrosion. In China, morpholine is almost blank due to its low yield and high price. In the future, with the increase of morpholine production and the decline of market prices, the application of anti-corrosion technology will be more and more.