The Effect of Thickener on EP Additive Response
Greases can be described as lubricating compositions composed of base oil and performance additives entrapped in a network of solid thickener particles, platelets, clumps and/or fibers. The interactions of thickener with base oil, additives and surfaces are recognized as having a significant effect on additive performance, especially for soluble EP and antiwear additives that function at mating surfaces. Specifically, it has been proposed that thickener reduce the ability of additives to get to surfaces by chemically binding additives or by competing with additives for surface area. However, there are few published studies that have detected and/or measured the effect of these interactions on EP and antiwear additive function.