Lubricity of fluorinated alkyl aryl ethers

A series of fluorinated alkyl aryl ethers, composed of hydrocarbon components, fluorinated alkyl groups, and ether linkage groups, were evaluated through a variety of tests to investigate lubricating properties. The basic molecular structure with tetrafluoroethoxyphenyl groups were shown to have excellent lubricities. However, ortho-position substituents to ether linkage groups diminished extreme-pressure properties. Excellent lubricities were suggested to be due to strong coordination of ether oxygen atoms to metal surfaces, and formation of iron fluorides on the metal wear surfaces.