Investigations of Antifriction Films Formation in Dioctyl Sebacate Medium with Cholesteryl Esters

Abstract

In the article, investigations of antifriction films formation at friction in dioctyl sebacate (DOS) medium with additives of cholesteryl esters of caproic and oleic acids. The relevance of the study is due to the development of biodegradable lubricants. The time required to achieve a friction coefficient of 0.02 in DOS medium occurs after 20,000 s from the start of the test, in DOS with 3% LCKA medium after 13,000 s, and DOS with 3% LCOA medium after 1000 s. The elemental analysis of antifriction films showed that the films contain organic and inorganic components. The organic part consists of dioctyl sebacate molecules. The inorganic part includes iron compounds. Cholesteryl esters are capable of planar orientation on friction surfaces and form layered structures in the zone of tribocontact. This provides an additional reduction in the friction coefficient and an increase in the energy-saving properties of the lubricant. This effect is achieved due to the realization in the friction zone of the mesomorphic state of a lubricant, which is characterized by an ordered oriented arrangement of the molecules of the mesogenic additive.