Synthesis and tribological behavior of fatty acid constituted tetramethylguanidinium (TMG) ionic liquids for a steel/steel contact.

In the present study a number of fatty acid constituted ionic liquids having tetramethylguanidinium ion as a cationic counterpart were synthesized by neutralization of 1,1,3,3‑tetramethyguanidine (TMG) with fatty acids having varying degree of alkyl chain and olefinic bonds. The structure of the synthesized ionic liquids was thoroughly characterized using a number of analytical tools such as TGA, FT-IR, 1H and 13C NMR spectroscopy. The tribo-properties of the obtained ionic liquids as high performance anti-friction and wear reducing additives were studied in different dosage to mineral base oil under condition of mixed/boundary lubrication. It was found that the anti-wear and friction reduction properties of blends were improved with increasing the alkyl chain in constituted fatty acid ionic liquids.