Probing the Synergy of Calcium Sulfonate Complex Soap and Polyurea Complex Thickener Toward Good Lubrication and Rheological Properties

Polyurea complex thickener was introduced into calcium sulfonate complex grease (CSCG) to prepare a new type of grease. The microstructure, rheological properties, and tribological properties of new greases were studied in detail. The experimental results show that the combination of calcium sulfonate complex soap and polyurea complex thickener can form a new thickener system, which combines the layered structure of calcium sulfonate complex soap and the rod-shaped structure of polyurea complex thickener. The thermal decomposition temperature of new greases is reduced, but their fluidity is improved and the friction coefficient is lower. Their synergistic effect is related to the special structural skeleton of the new thickener system, and calcium sulfonate and urea molecules share the same calcium ion, which may be an important reason for maintaining the stability of this special structure skeleton.