Specific Features of Greases Based on Poly-α-olefin Oils with Ureate Thickeners of Various Structures

Abstract

Greases based on poly-α-olefin oils of various viscosities, thickened with diureas of various structures, were studied systematically. The influence of the base oil viscosity and/or thickener structure on the physicochemical properties of lubricants was demonstrated. Diurea thickeners differing in the length of the hydrocarbon substituent influence the properties of lubricants prepared with base oils of similar chemical nature but different viscosity in different fashion. The revealed trends were confirmed by rheological studies in a wide range of shear rates. Tribological measurements at loads in the interval 20–80 kgf demonstrated significant dependence of the antiwear properties of ureate lubricants based on low-viscosity poly-α-olefin oils on the thickener structure. This dependence becomes less pronounced in going to higher-molecular-mass oils.