Friction- and Wear-Reducing Properties of Multifunctional Small Molecules

Abstract

Nitrogen- and oxygen-containing compounds were designed empirically and subsequently synthesized, and their rheology, friction, and wear performance as multifunctional base oils (MFBOs) were evaluated. Two of the compounds displayed good viscosity/rheology profiles without the addition of polymeric viscosity modifiers, displaying high viscosity indexes (VIs) above 200. Furthermore, all three MFBOs had lower coefficients of friction compared to well-established and accepted benchmarks. The most significant advancement is their impressive wear improvement by a factor of 5.5 to 70 compared to either of the benchmarks, which is attributed to the polar nature of the base oil which promotes boundary lubrication with metal surfaces. Moreover, these compounds were easily synthesized in one step from commercial starting materials. This work demonstrates that a careful design could provide the features/performance/functions of base oil, rheology modifiers (or VI improvers), and antiwear and friction-reducing additives, all-in one molecule.