Study on the relations between the colloidal structure and performance of lubricant oil detergent

The characteristics and performances of several calcium alkylsalicylates which are used in lubricating oil were studied. The relations between the content of alkaline components and total base number of detergent as well as micellar stability were studied. The diameter and the distribution of loading-carrying (carbonate-containing) micelle were measured by freeze-etching replication and electron microscopic observation method and infrared absorption methods. Four-ball machine tests were used to study the anti-wear performance of series of calcium alkylsalicylate products. The research results show that the micellar structure of detergents has an important influence on the performance of products. The particle diameter decreases while the total base number of the detergent increases. The smaller the diameter is, the more uniform the particles distribution is and the better the micelle stability is. And the detergency, thermal oxidization and anti-wear abilities have improved distinctively due to the increase of the content of alkaline components in detergents.