Development of the Method and Optimization of the Composition and Modes of Obtaining the Biodegradable Grease With the Lithium-Calcium Thickener

Abstract

It is noted that the development of biodegradable lubricants is an integral part of the development of a modern “green” economy. The distinctive features of the proposed method are described for producing a biodegradable grease on a mixed lithium-calcium thickener, providing for the introduction of alkaline initial components of the dispersed phase (lithium hydroxide monohydrate and calcium hydroxide) into the reaction mass not in the form of their aqueous solutions, but in a powdery state, and the exception of prolonged exposure to water and high temperature on a component of a dispersion medium of plant origin (rapeseed oil) in the process of lubricant synthesis. Along with this, it was proposed to use a highly refined oil of group III according to the API (American Petroleum Institute) standard as a mineral component of the dispersion medium. This provides, in aggregate, the higher stability of the rheological and tribological characteristics of the grease (for at least 12 months) at a given level of biodegradability. The experimental-statistical mathematical model of the process of obtaining the biodegradable lithium-calcium grease is developed, which makes it possible to determine the parameters of the component composition (the content of the mixed lithium-calcium thickener in the grease and the content of lithium stearate in the mixed thickener) and the synthesis modes (the heat treatment temperature of the reaction mass) to achieve the given level of the main characteristics of the finished grease (penetration, dropping point) while ensuring its biodegradability of at least 80 %.