Guanidine based amino acid derived task specific ionic liquids as noncorrosive lubricant additives for tribological performance

Abstract A series of task-specific ionic liquids derived from 1,1,3,3-tetramethylguanidine (TMG) and amino acids such as L-histidine, L-glutamic acid, and L-aspartic acid successfully synthesized and characterized using Fourier transform infrared spectroscopy (FT-IR), 1H & 13C nuclear magnetic resonance spectroscopy (NMR). Physiochemical properties, such as viscosity, viscosity index, and density, as well as the tribological performance concerning friction and wear of the synthesized [TMG][AA] IL additives, were investigated. The anti-corrosion behavior of the ionic liquids was examined by immersion of steel test specimen in their blends with base fluid PEG 200 at 2 wt% concentration. Among all the synthesized ILs, the IL derived from TMG and aspartic acid exhibited best performance in terms of reduction in friction and wear along with the non-corrosive nature.