Abstract
Room-temperature 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid (IL) reduces friction and wear of epoxy resin/AISI 316L stainless steel contacts when used as neat external lubricant. In order to study the internal lubricant performance of IL, variable concentration epoxy+IL dispersions containing 0.5-3.3 wt.% IL were obtained by mechanical mixing and casting. SEM cryofracture and EDS show dispersed rounded IL particles within the epoxy matrix. The new dispersions have slightly lower Tg and hardness values than the unmodified resin. Fracture modes and tensile strength are similar for epoxy and epoxy+2.7%IL, although the elongation at break reduces in presence of IL. Pin-on-disc tests show that dry friction coefficients decrease exponentially as the IL proportion increases and wear resistance improves in several orders of magnitude for a critical IL concentration of 2.7 wt.%. Wear mechanisms are discussed on the basis of SEM and AFM observations. The surface modification of the new dispersions gives lower static and dynamic friction coefficients when sliding against steel or polytetrafluoroethylene sheets under mild conditions.
© 2013 by Walter de Gruyter GmbH & Co.
