Preparation and tribological properties of attapulgite – bentonite clay base grease

Abstract

Purpose – The mixture of attapulgite and bentonite was used as a thickener, and polyalphaolefin was used as the base oil to prepare the new lubricating grease. Some solid particles such as Polytetrafluoroethene (PTFE), MoS2, nano-calcium carbonate and graphite were added in the new lubricating grease as anti-wear additives to investigate the tribological sensitivity. Design/methodology/approach – The new lubricating grease was evaluated by optimol-SRV reciprocating friction and wear tester, and the wear volumes were determined using a MicroXAM-3D. At the same time, the dropping point and the cone penetration were investigated and analyzed. The tribological properties of the new lubricating grease and the sensitivity of some solid lubricating additives to the new lubricating base grease were investigated; pure organic-bentonite and pure organic-attapulgite base grease were used as contrast. Findings – The new lubricating grease based on the surface-modified bentonite/attapulgite clay base grease was synthesized with a relatively high dropping point, and the mass ratio is 25/75 bentonite/attapulgite clay base grease, having a better tribological performance. MoS2 was used as an anti-wear additive that has good tribological sensitivity to the new lubricating base grease. Originality/value – The main innovative thought of this work lies in the mixture of attapulgite and bentonite used as thickener. A relevant report is not available at present.