Synthesis and lubrication characteristics of aryloxycyclophosphazenes substituted with imidazolium

A series of new aryloxycyclophosphazene derivatives substituted with imidazolium ionic liquids was synthesized. Their tribological properties were investigated on an Optimol SRV IV oscillating friction and wear tester in ambient condition. An electric field was imposed between the ball and disk to monitor the tribochemical reaction by means of "contact resistance." These ionic liquids substituted cyclophosphazene derivatives present lower friction coefficient and wear volume loss than tetrakis-(3-trifluoromethylphenoxy)-bis(4-fluorophenoxy)cyclotriphosphazene. The polarity of ionic liquids is believed to provide strong adsorption to contact surfaces and can form a boundary lubricating film leading to friction and wear reductions. Introducing the ionic liquids to cyclophosphazene may be a new method to improve the tribological properties of cyclophosphazene derivatives.