A Study on the Extreme Pressure and Antiwear Behaviour of Some Bisphenyl Ether Derivatives Containing Different Substituents in Their Molecular Structures

The extreme pressure (EP) and antiwear (AW) properties of some bisphenyl ether derivatives containing different substituents in the ring were investigated using a four ball machine and a SRV tester. The wide difference has been observed in these compounds. It was found that the EP and AW properties of bisphenyl ether derivatives are dependent on the nature, position and number of the substituents in the rings. 2-Nitro4-trifluoromethyl 2', 4'-dichlorobisphenyl ether is appreciably more effective in reducing wear than its analogues in four ball wear test. 3-Trifluoromethyl 4'-nitrophenyl ether is highly effective in anti-scuffing in SRV load carrying test. The results also shown that the thionophosphoramidation makes phenyl ether have both excellent anti-wear effectiveness and anti-scuffing effectiveness being superior to other bisphenyl ether derivatives. Multiple functional groups, such as S,P.O and N containing groups, in a single additive molecule could increase the chance of the molecular interaction with the surface without making any bound too active. Therefore, the corrosive wear of EP additive could be controlled if the different function groups are well matched and balanced. Additional work will be necessary to provide further insight into the mechanisms of the matching effect of functional groups before it can be used as a theoretical guide for the development of new multifunctional additives.