A Comparative Study On Tribological Properties Of Several Leaf-surface Waxes Extracted From Coastal And Inland Plants

The components of leaf-surface wax extracted from the plant growing in different environments are usually different.In this paper,eight kinds of leaf-surface waxes were extracted from shrubs and arbors growing in coastal and inland,and a gas chromatography-mass spectrometry(GC-MS)was employed to analyze the chemical composition of leaf-surface wax;the synthetic ester was used as base oil to prepare lubricating oil and grease,and the tribological properties were evaluated by using a MFT-R4000 reciprocating friction and wear tester;the surface morphologies of wear scars were observed by using optical microscopy and scanning electron microscopy(SEM).and the chemical composition and functional groups on the wear scar surface were analyzed by using energy dispersive spectroscopy(EDS)and time-of-flight secondary ion mass spectrometry(TOF-SIMS).Finally,the tribological data were calculated and compared,and the wear scars were fitted by using Matlab and other software.The final conclusions are as follows:1?The leaf-surface waxes used as the friction reduction and anti-wear additive of lubricating oil and grease have excellent lubricating ability.Compare arbor leaf-surface waxes and shrub leaf-surface waxes,the friction reduction capacity of leaf-surface waxes extracted from arbors are better,while the waxes extracted from shrubs have better anti-wear capacity.The friction reduction and anti-wear capabilities of the leaf-surface waxes extracted from coastal plants are better than those extracted from inland plants,and it is especially true when the plant species are the same.2?Through gas chromatography-mass spectrometry and time-of-flight secondary ion mass spectrometry,it can be seen that the long chain ions of leaf-surface waxes crack into short chain ions in the process of friction,increasing the concentration of ions,and these ions form a superior lubricating film on the worn surface by adsorption to show friction reduction and anti-wear abilities.Research shows that acids,alcohols and esters in leaf-surface wax have excellent lubricating ability because they have strong polar functional groups which are more likely to form an adsorption film on the friction surface.3?The tribological data were calculated and compared,and the wear scars were fitted by using Matlab and other software,so that the three-dimensional images of wear scars are obtained.The wear on the worn surface can be analyzed more intuitively by the obtained images.