USING OF ESTERS AS DISPERSION MEDIUM OF POLYUREA PLASTIC GREASES

Abstract

This article presents first results of the investigated physico-chemical and operational parameters of composition greases obtained with the use of esters of different nature as a dispersion medium and the polyurea as a thickening agent, including the addition of nanocellulose. The choice of the ester base for the production of greases is possible due, on the one hand, to good combination of the physico-chemical properties (high viscosity index, low volatility, high flash and ignition temperature, low pour point, good anti-wear properties). On the other hand, in the production of greases with good ecological characteristics biodegradability of its components is of great importance, which in this case is provided by the use of esters as an oil base and an organic thickener, nanocellulose, as a component of the polyurea dispersed phase. It has been shown that from the dicarboxylic acid esters studied, the polyurea greases based on dioctyl adipate are superior to the dropping point and better colloidal stability as compared to dioctyl sebacate and dibutyl sebacate. The smaller size of the ether molecule provides the stronger structure of the polyurea grease. Similarly, for branched ethers, the grease based on tri-basic alcohols is more effective than the four-basic alcohols. The possibility of using nanocellulose as a thickener component was demonstrated. An increase in the content of nanocellulose to 3.5% increases the colloidal stability and the dropping temperature of the synthesized greases. The obtained samples have a wider range of operating temperatures, better rheological indicators than imported and domestic analogues.