Preparation And Tribological Performance Of Imidazoline Borates With Heavy Naphthenic Acid As Feedstock

Xinjiang Karamay crude oil,as a typical naphthenic oil,is a good raw material for preparing lubricant base oil with low pouring point.In the process of solvent refining,the heavy naphthenic acid would be produced from VGO.The annual production is about ten thousand tons and this number has been increasing year by year.The heavy naphthenic acid is different from the light naphthenic acid from kerosene and diesel,since the former is characterized by low acid value,large relative molecular weight,high viscosity,and dark color.Since the heavy naphthenic acid has not been fully developed and utilized,it is important to enhance utilization value of heavy naphthenic acid through chemical modification.In this thesis,some imidazoline borates were prepared using the heavy naphthenic acid as feedstock,and their tribological performance were tested in detail.The basic properties of the heavy naphthenic acid were determined,such as density,viscosity,acid value and chemical structure.Using the heavy naphthenic acid and ?-hydroxyethyl ethylenediamine as raw materials,the imidazoline intermediate was synthesized.Then the imidazoline borates were finally prepared using the imidazoline intermediate,solvent,boric acid and alcohols with different carbon number as feedstocks.For the contrast of the heavy naphthenic acid,Oleic acid,Stearic acid or Light naphthenic acid was used to produce the corresponding borates.All of the imidazoline borates were characterized by infrared spectrometer in detail.The oil solubility and the hydrolysis stability of additives were evaluated and their tribological performance in base oil(150 BS-500 SN)was tested by Four-ball testing machine.The effects of the concentration and the load on wear scar diameter were studied.The results showed that the additives prepared with the imidazoline intermediate,boric acid and alcohols,were good for the oil solubility and the hydrolytic stability.Adding the additives to the base oil,the wear scar diameter decreased and the carrying capacity increased,but the extreme pressure performance was not obviously improved compared to the additives contained sulfur or phosphorus.In general,the imidazoline borate(H-BN5)using the heavy naphthenic acid as feedstock has good oil solubility and anti-wear performance.H-BN5 was combined with the traditional extreme pressure agent sulphide isobutene(T321)and the tribological performance of the combined system was researched.It showed that the anti-wear performance of T321 was poor when used in isolation,but the anti-wear performance would be improved significantly when combined with H-BN5.All in all,the extreme pressure performance of H-BN5 and the anti-wear performance of T321 were obviously improved when these two additives were combined.