氨基酸离子液体润滑剂的结构与摩擦学行为的关系

利用酸碱中和法合成了一系列季铵盐和季膦盐氨基酸离子液体(AAILs)润滑剂,以合成润滑油聚α-烯烃(PAO10)和传统含氟离子液体1-丁基-3-甲基咪唑双三氟甲烷磺酰亚胺盐(L-F104)作为参照样,评价了粘温性能、热稳定性以及作为不同摩擦副润滑剂的润滑性能,探索了阴、阳离子结构对其物理化学性质和摩擦学性能的影响规律。结果表明:季膦盐氨基酸离子液体的粘温性能和热稳定性明显优于季铵盐氨基酸离子液体;这些离子液体中,阴离子上硫元素的引入可显著提高其粘温性能,而芳环的引入却使其粘温性能明显下降。结构对其摩擦学性能的影响规律与摩擦副种类有关:当钢/钢、钢/铜摩擦副作为润滑剂时,在常温或高温条件下,均具有优异的减摩抗磨性能;当钢/铝摩擦副作为润滑剂时,只有含芳基的季铵盐氨基酸离子液体具有优于PAO 10和L-F104减摩抗磨性能。

Relationship Between Molecular Structure and Tribological Performance of Amino Acid Ionic Liquid Lubricant

A series of quaternary ammonium and phosphonium amino acid ionic liquid (AAILs) lubricants were synthesized through a neutralization reaction. Using synthetic oil poly-alpha-olefin (PAO 10) and 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide (L-F104) as the reference samples, the viscosity-temperature characteristics, thermal behaviors and tribological properties as lubricants for various friction pairs were investigated. The relationship between their molecular structures and tribological performance was discussed. Results show that the viscosity-temperature characteristics and thermal behaviors of the quaternary phosphonium AAILs are superior to those of quaternary ammonium AAILs. The viscosity-temperature characteristics of the ILs can be obviously improved by the introducing of sulfur element, while it is decreases by the introducing of aromatic ring. The tribological performances of the AAILs vary with different friction pairs. Excellent friction-reducing and anti-wear properties are detected both at room and high temperature when the AAILs are used as lubricants for steel/steel and steel/copper friction pairs. However, only quaternary ammonium ILs bearing aromatic rings has better friction-reducing and anti-wear properties compared with PAO 10 and L-F104 when applied on steel/aluminum friction pairs.