The development of polyurea greases based on paraffin-naphthenic lubricating oil VHVI-4

The purpose of this work was to improve the tribological characteristics and low-temperature properties of polyurea greases, as well as to expand the operating temperatures of their use. In this work, as the dispersion medium were used base oils of groups I (I-20) and III (VHVI-4). Diurea was used as a thickener. The obtained samples of the lubricating greases were analyzed: penetration (GOST 32331-2013), drop-point temperature (GOST 32394-2013), colloidal stability (GOST 7142-74), tribological characteristics (GOST 9490-75), and effective viscosity at -50ºС (GOST 26581-85). Based on the analysis of the obtained data, it was concluded that the best properties have lubricants prepared on the group IIIbase oils. To improve the low-temperature properties, it was proposed to add a 50% ester (DOTF) to the dispersion medium of greases which have better performance.As a result of work done, we concluded that the polyurea greases improved their tribological characteristics and low-temperature properties after adding ether to VHVI-4 (1:1) as a dispersion medium.