The antiwear and extreme pressure properties of some oil-water double soluble rare earth complexes Part 2: their tribological behaviours in liquid paraffin

Abstract

The tribological behaviours of the complexes in the title as additives in water were investigated in Part 1 of this work. Here in Part 2 their antiwear and extreme pressure properties as additives in liquid paraffin are dealt with and compared with the commercially available ester of di- n-dodecyl-polyethylene-epoxyphosphate. Their antiwear and extreme pressure properties in liquid paraffin were evaluated on an Optimol SRV fretting wear tester, while the worn surfaces were analysed on an electron microscope and electron probe micro-analyser. Then a model was established to explain the difference in their tribological behaviours in water and liquid paraffin. It was found that although these complexes exhibit better antiwear and extreme pressure properties in water than in liquid paraffin, they can be used as promising additive candidates in both water and oil. Meanwhile, it is proposed that their different tribological properties in water and oil are closely related to their different adsorption actions therein.