YAO Meihuan^1*, YUE Yuanyuan¹, ZHANG Yimin¹, XIA Yanqiu², ZHOU Feng², LIYANG Yongmin²

(1.School of Chemistry and Environmental Science, Henan Normal University, Xinxiang 453007, China 2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China)

Abstract: Three kinds of dicationic imidazolium ionic liquids (ILs) linked with different carbon chains were synthesized. An SRV-IV type friction and wear tester was performed to evaluate the tribological properties of as-synthesized ILs at elevated temperatures from 50 ℃ to 350 ℃ and at a constant temperature of 250 ℃. The morphology and elemental composition of the wear scars were analyzed by means of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results indicate that, as compared with the friction and wear test at varied temperatures, the tests at a constant temperature of 250 ℃ are more effective in differentiating the tribological properties of dicationic imidazolium ILs at elevated temperatures. In the meantime, the dicationic imidazolium ILs linked with alkyl bridge possessed better friction-reducing and anti-wear abilities than those linked with polyethylene glycol, and decreasing length of the alkyl linking chain of the dicationic ILs can improve their tribological properties.

Key words: dicationic imidazolium ionic liquids; synthesis; tribological properties at elevated temperature

E-mail: gtymh@163.com 

Tribology, Vol. 31, Issue 5, 2011, 485~491