Investigation of the Interaction, Rheological and Tribological Properties of Bis(pinacolato)diboron with Lithium Grease

Abstract

In this article, Lewis acid–base complex of lithium 12-hydroxystearate (LHS) with diboron compound is formed by the introduction of bis(pinacolato)diboron (B2Pin2) into lithium grease. The interaction between Lewis acid B2Pin2 and Lewis base RCO2− of LHS is characterized by various techniques. Moreover, the rheological and tribological behaviors of the base grease are evaluated at low and moderate temperature. The results indicate that the addition of B2Pin2 can noticeably enhance the rheological property of the base grease because the formation of Lewis acid–base complex is beneficial for improving the soap fiber structure strength, and B2Pin2 could also help reduce the friction and wear of the grease during the sliding process, which likely owing to the boundary lubrication film generated by B2Pin2 adsorption on the rubbing surface and tribochemical reaction between borate esters and steel surfaces. The improvement of mechanical stability and tribological properties is beneficial to increasing the grease service life. Graphical Abstract

The size effect of typical micro‐ and nano‐calcium carbonate additives on the friction properties of calcium sulfonate grease

“…If the loss modulus (G″) exceeds the storage modulus (G′) out of the LVE, greases exhibit transitions from grease‐like to fluid‐like at this point. Therefore, the shear stress of intersection could reflect the crosslinked microstructure strength of the grease 33–35 . As for all tested CSG, when the temperature was from 30 to 80°C, the structural strength was somewhat reduced due to the influence of temperature.…”

“…Therefore, the shear stress of intersection could reflect the crosslinked microstructure strength of the grease. [33][34][35] As for all tested CSG, when the temperature was from 30 to 80 C, the structural strength was somewhat reduced due to the influence of temperature. It is also obvious that at all shear strains, both storage (G 0 ) and loss (G 00 ) for the CSG with nCaCO 3 or mCaCO 3 were slightly higher than the base grease whether 30 or 80 C. This might be attributed to the formation complex of thickener with solid particles, which can effectively improve the structural strength of the grease and prevent it from thinning at high temperature.…”

The Optimization Study of Rheological Characteristics of Wind Power Grease Based on Gel-State

“…However, friction wear is an unavoidable phenomenon in wind turbines [10]. To reduce energy consumption and extend the service lifespan of wind turbines, grease plays a dual role with its excellent rheological characteristics, which can effectively lubricate and provide excellent sealing effectiveness [11,12]. However, the carbon emissions generated during the preparation and utilization of traditional grease have become an important factor limiting the sustainable development of wind turbines [13,14].…”