Highly thermally stable cyclotriphosphazene based perfluoropolyether lubricant oil

Novel cyclotriphosphazene based lubricant oil (Lube-PN) for heat-assisted magnetic recording media was synthesized by reacting hexachlorocyclotriphosphazene with pentafluorophenol, followed by treatment with a hydroxy-terminated perfluoropolyether in a high yield. Its chemical structure was confirmed by 1H and 31P NMR. Its properties including viscosity, thermal stability, tribology, laser resistance as well as mobility behaviour on the hard disk surface were investigated. The thermal properties of Lube-PN were analysed using thermogravimetric analysis, and the thermal aging results showed that the about 80% of Lube-PN was retained even after heating at 300 °C for 8 h. The Lube-PN also exhibited comparable bonding ratio, friction coefficient, moderate mobility and better laser resistance than commercial perfluoropolyether based lubricant oils.