| Borate ester is one of the hot topic in the research field of lubricating oil, for the borate ester has no ash, no phosphorus, no pollution, and good biodegradable properties which can be widely used in lubricating oil, to improve the oxidation stability of lube oil, anti-friction and anti-wear extremely pressure performance, etc. But as a result of the boron atom in borate ester is lack of electricity, easy to hydrolysis under the influence of water.its hydrolytic stability is weak, which made the borate ester used in water-based rather difficult. In recent years the development of borate ester containing nitrogen greatly improves the hydrolytic stability of borate ester, borate ester containing nitrogen was applied to water base are also possible. In this paper, three kinds of nitrogen boric ester was synthesized through the view of molecular design:hydrazine boric ester, 2- mercaptobenzothiazole hydrazine borate ester(MNB), benzotriazol hydrazine borate(NNB), applying in the rapeseed oil, water- ethylene glycol respectively, the water- glycol lubricanting fluid, inspecting the tribological performance. And the Gaussian software is used to calculate the above three kinds of borate ester and its hydrolysate of boron atoms in charge, then optimize the structure of the three kinds of borate ester, to explore the hydrolysis of hydrazine-containing borate ester. At the same time studying the tribological collaborative properties of the compound additive commercially available T321 and benzotriazol hydrazine borate(NNB). All the tribological properties and calculation results are as follows:1. The compounded triethanolhydrazine borate exhibited good hydrolysis stability,which is 2800 times of triethyl borate and is 2.3 times of triethanolamine borate. What’s more under low load the trithanolhydrazine borate ester had good extremely pressure, antifriction and wear-resistant properties. Using XPS and SEM to investigate the wear composition and formation of the structure of the boundary film on the surface of the steel ball, the results show that the additive to join all adsorption in the steel ball surface, mainly formed a deposited film of B2O3 and predominantly nitrogen adsorption film. Which combined a complicated lubricating film to prevent further friction and wear.2. The synthesized MNB exhibited good lubrication performance in the water- glycol.Containing 2.0% MNB water-base fluid its extremely pressure value is more than 2.5 times of pure water base, at the same time to improve the antiwear and friction-reducing water-base fluid in different degrees. Through theoretical calculations found that the hydrolysis stability of MNB mainly through BN coordination and space steric hindrance to enhance. Using SEM,EDS to investigate the worn steel ball surface and element content, found containing active element B, S, N of MNB recombination to form a new chemical membrane, reduce the wornof the ball.3. Through the theoretical calculation, founding the compounded NNB hydrolytic stability is better than the hydrazine borate ester. Containing NNB water-base fluid has excellent anti-wear and friction-reducation properties, under the low load(98 N), the wear scar diameter of aqueous solution containing 2.5% NNB is 30% smaller than water base fluid. In the process of friction, the surface of the steel ball forming the lubrication film polishing effect, reduce the worn of the steel ball surface.4. When the T321 and NNB distribution ratio is 1:1, its tribological properties is superior than the single dose T321 and NNB, the sample liquid load is the water-base of more than three times, its antiwear friction-reducation effect is the best of all the distribution test solution, it shows that the mixture reagent T321 and NNB have tribological collaborative performance. By SEM, EDS analysis found that additives in the steel ball surface formed a lubrication film which contains the active elements such as N, S, B to prevent the further friction and wear. |
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