Tribological and rheological performance of lithium grease with poly-α-olefin and alkyl-tetralin as base oils

Abstract

A new category of lithium greases was synthesized by using poly-α-olefin (PAO8) and alkyl-tetralin as base oil, where the alkyl-tetralins were synthesized by the alkylation of tetralin and olefins. The influence of thickener concentration, alkyl-tetralin content and type of blend oils on the rheological and tribological performance of lithium grease was investigated. The microstructures of soap fibers were measured to reveal the structure-property correlations. The concentration of thickener and alkyl-tetralin content obviously affect the lubricating performance of lithium grease, while the molecular structure of alkyl-tetralin has no obvious impact on their properties. It was found that alkyl-tetralin could significantly enhance the thickening ability of PAO8 base oils, and decrease the amount of thickeners by 1.5% (mass). Lithium greases prepared using 20% (mass) alkyl-tetralin as co-base oil exhibited high colloidal stability, excellent rheological behaviors and tribological properties.