When the internal combustion engine is working, the engine oil is subjected to high temperature and high pressure. It comes into contact with oxygen and various metals to undergo oxidative condensation and decomposition, forming a series of substances that will be deposited and attached to the engine parts in the form of carbon deposits, paint films and sludge, making the engine work. Conditions deteriorate. Therefore, detergent and dispersant are usually added to lubricating oil to disperse and solubilize the coke, sludge and acidic oxidation products generated in the oil to ensure the normal operation of the engine.
In 1955, DuPont of the United States developed a new type of polymeric dispersing additive, a copolymer of 12-14 methacrylate and diethyl aminoethyl methacrylate. Because it contains no metal and burns without ash, it is called an ashless additive.
Ashless dispersants are a type of lubricating oil additive that does not contain metal and can effectively disperse sludge, paint film, sludge and other substances generated by oil into the oil.
As one of the main additives of internal combustion engine oil, ashless dispersant’s main function is to disperse and solubilize sediments such as sludge, paint film, coke and soot in the oil, keep them in suspension, and prevent their deposition and agglomeration. , reduce wear and viscosity increase, extend the oil change interval and the service life of the internal combustion engine.
However, it is not enough for an ideal ashless dispersant to simply have good dispersion properties. Good thermal stability can prevent it from decomposing and failing in the high-temperature working environment of the engine; good oxidation stability can prevent itself from turning into deposits; good low-temperature stability in terms of engine cold start and fuel economy, etc. Performance is also essential.