阅读说明：本技术 一种抗氧体系自修复润滑油添加剂的制备方法 (Preparation method of antioxidant system self-repairing lubricating oil additive ) 是由 申慧君 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种抗氧体系自修复润滑油添加剂的制备方法,步骤如下：1)利用草酸对磷灰石进行处理,制得草酸改性磷灰石；2)利用有机抗氧剂作为修饰剂制得有机抗氧剂修饰的改性磷灰石；3)在聚乙烯醇水溶液中加入硼砂,经反应制得改性聚乙烯醇水溶液；4)对碳纳米管进行活化处理,制得活化碳纳米管；5)利用四甲基氢氧化铵作为催化剂,六甲基环三硅氧烷经开环反应再经接枝聚合制得具有自修复功能的添加剂。该添加剂与润滑油有很好的相容性,可以均匀的分散并稳定的存在于润滑油中,不仅可以对金属表面因摩擦造成的缺陷进行自修复,同时还可以提高润滑油的抗氧化性,可以有效的防止润滑油因氧化而失效,很好的延长了润滑油的使用期限。(The invention discloses a preparation method of an antioxidant system self-repairing lubricating oil additive, which comprises the following steps: 1) treating apatite by using oxalic acid to prepare oxalic acid modified apatite; 2) preparing modified apatite modified by organic antioxidant by using the organic antioxidant as a modifier; 3) adding borax into a polyvinyl alcohol aqueous solution, and reacting to prepare a modified polyvinyl alcohol aqueous solution; 4) activating the carbon nano tube to prepare an activated carbon nano tube; 5) tetramethyl ammonium hydroxide is used as a catalyst, and hexamethylcyclotrisiloxane is subjected to ring-opening reaction and graft polymerization to prepare the additive with the self-repairing function. The additive has good compatibility with lubricating oil, can be uniformly dispersed and stably exist in the lubricating oil, can self-repair the defects caused by friction on the metal surface, can improve the oxidation resistance of the lubricating oil, can effectively prevent the lubricating oil from losing efficacy due to oxidation, and well prolongs the service life of the lubricating oil.)

1. A preparation method of an antioxidant system self-repairing lubricating oil additive is characterized by comprising the following steps:

1) taking 4-6 parts of apatite, crushing and grinding to obtain apatite powder, adding the apatite powder into 0.5-0.8mol/L oxalic acid solution according to the solid-to-liquid ratio of 1:10-15g/ml, culturing for 3-5 days at 30-35 ℃, and then drying in an oven at 50-60 ℃ for 5-7 hours to obtain oxalic acid modified apatite;

2) adding oxalic acid modified apatite into distilled water, stirring for 20-30min at 300r/min of 200-15% to prepare oxalic acid modified apatite dispersion liquid with the mass fraction of 10-15%, then adding 30-50 parts of sodium hydroxide solution, stirring and mixing for 20-30min at room temperature at the rotating speed of 50-100r/min, then carrying out suction filtration, adding the washed solid product into ethanol solution, oscillating and dispersing for 15-25min under 300-400W ultrasonic wave, then adding 2-3 parts of organic antioxidant, stirring and reacting for 2-3h at room temperature at the rotating speed of 80-130r/min, then adding 0.5-0.8 part of amine compound, reacting for 5-7h at 50-60 ℃, centrifugally separating after the reaction is finished, washing the solid product, purifying, and purifying, Drying to obtain modified apatite modified by organic antioxidant;

3) adding 20-30 parts of polyvinyl alcohol into deionized water, stirring for 30-40min at a rotation speed of 100-150r/min in a greenhouse, then placing the mixture in an oven at a temperature of 80-90 ℃ until the mixture is completely dissolved to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 5-8%, then adding 3-4 parts of borax into deionized water, heating to 40-50 ℃, stirring and dissolving to prepare a borax aqueous solution with a mass fraction of 2-4%, then mixing and stirring the polyvinyl alcohol aqueous solution and the borax aqueous solution uniformly at a temperature of 70-80 ℃, keeping the temperature for 20-30min, adding 1-2 parts of tributyl phosphate, cooling to 50-60 ℃, and reacting for 3-5h to prepare a modified polyvinyl alcohol aqueous solution;

4) taking 3-5 parts of carbon nano tube, drying after acidification, then fully mixing with potassium hydroxide powder in a mortar according to the weight ratio of 1:4, then placing the mixture in a ceramic boat, placing the ceramic boat in a tube furnace, firstly introducing nitrogen for 40-50min at normal temperature at the flow rate of 150-;

5) taking 10-15 parts of hexamethylcyclotrisiloxane and 1-2 parts of 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane, mixing, adding 0.1-0.3 part of tetramethylammonium hydroxide, placing in a dry reactor filled with nitrogen, reacting for 10-15h at the temperature of 100 plus-120 ℃, then heating to the temperature of 180 plus-200 ℃, preserving heat for 10-30min, then cooling to the temperature of 150 plus-160 ℃, vacuumizing to 10-20kPa, adding the obtained sticky liquid into a modified polyvinyl alcohol aqueous solution, then adding 0.05-0.1 part of N, N-dimethyl bisacrylamide, 0.03-0.05 part of potassium persulfate, modified apatite modified by an organic antioxidant and an activated carbon nanotube, stirring for 1-2h at the rotation speed of 130 plus-180 r/min, then adding the solution into a reactor, charging nitrogen for 20-30min, heating to 80-90 ℃, reacting for 3-5h at constant temperature, drying the product in a 50-60 ℃ oven to constant weight, and grinding to obtain the additive with the average particle size of 10-15 um.

2. The method for preparing the antioxidant system self-repairing lubricating oil additive as claimed in claim 1, wherein in the step 1), the average particle size of the apatite powder is 20-50 um.

3. The preparation method of the antioxidant system self-repairing lubricating oil additive as claimed in claim 1, wherein in the step 2), the mass fraction of the sodium hydroxide solution is 15-20%; the organic antioxidant is hindered phenol antioxidant and is selected from any one of 2, 6-tertiary butyl-4-methylphenol, bis (3, 5-tertiary butyl-4-hydroxyphenyl) thioether and 3- (3, 5-di-tertiary butyl-4-hydroxyphenyl) propionic acid; the amine compound is selected from any one of tetraethylammonium hydroxide, tetrabutylammonium hydroxide and tetrapropylammonium hydroxide.

4. The method for preparing the antioxidant system self-repairing lubricating oil additive as claimed in claim 1, wherein in the step 4), the diameter of the carbon nanotube is 10-20nm, and the length of the carbon nanotube is 10-20 um.

5. The method for preparing the antioxidant system self-repairing lubricating oil additive as claimed in claim 1, wherein in the step 4), the carbon nanotube acidification treatment process is as follows: adding carbon nanotubes into concentrated nitric acid with the mass fraction of 80-85% according to the solid-to-liquid ratio of 1:30-50g/ml, soaking at 30-35 ℃ for 5-6h, then performing ultrasonic dispersion treatment at 60-70 ℃ for 20-25h at 300-500W, cooling, performing centrifugal separation, washing with distilled water until the filtrate is neutral, and drying at 50-60 ℃ to constant weight.

Technical Field

The invention belongs to the technical field of lubricating oil, and particularly relates to a preparation method of an antioxidant system self-repairing lubricating oil additive.

Background

At present, most of lubricating oil is added with a plurality of lubricating additives to improve the performance of the lubricating oil, and the traditional additives are generally taken to the surface of a friction pair by using the lubricating oil or lubricating grease as a carrier, and the materials and the metal surface generate chemical reaction under the action of friction energy to generate a special wear-resistant protective layer, so that the self-repairing of the metal surface is realized.

During the use process, the lubricant is catalyzed by oxygen in the air, byproducts generated by fuel combustion, high temperature, some metals and the like, and a series of chemical changes such as oxidation, polymerization, decomposition and the like can occur, so that a series of consequences such as corrosion, oil viscosity change, paint film and oil sludge are generated. Oxidation is the main cause of deterioration and deterioration of the lubricating oil, and greatly shortens the service life of the lubricating oil, so that an antioxidant is needed to improve the oxidation stability of the lubricating oil and provide an oil film repairing function for a worn surface, thereby further improving the antifriction and antiwear capacity of a friction pair under severe working conditions. However, under severe working conditions of high speed, high temperature, high pressure and the like, a large amount of peroxides, alcohols, hydroxy acids and the like are generated in the oil product, so that the viscosity of the oil product is increased, and when the amount of the antioxidant in the additive is less, the antioxidant requirement under the severe working conditions cannot be met, so that a large amount of the composite antioxidant is required to be used, the antioxidant performance of the oil product at different temperatures is improved, and especially the antioxidant effect at high temperature is enhanced.

Different types of antioxidants are applied to different fields, the sensitivity of the different types of antioxidants to different base oils is different, in addition, the increasing processing requirements are difficult to meet by means of a single antioxidant, and the synergistic effect of the different antioxidants not only can obtain excellent antioxidant performance, but also can obtain additional self-repairing performance. Therefore, for lubricating oils in different fields, it is necessary to select appropriate antioxidants to develop high-performance lubricating oils. The invention aims to provide a lubricating oil additive which has excellent oxygen resistance and plays a certain repairing role on a worn surface, and the service life of a machine can be effectively prolonged.

Disclosure of Invention

The invention aims to provide a preparation method of an antioxidant system self-repairing lubricating oil additive aiming at the existing problems.

The invention is realized by the following technical scheme:

a preparation method of an antioxidant system self-repairing lubricating oil additive comprises the following specific steps:

1) taking 4-6 parts of apatite, crushing and grinding to obtain apatite powder, adding the apatite powder into 0.5-0.8mol/L oxalic acid solution according to the solid-to-liquid ratio of 1:10-15g/ml, culturing for 3-5 days at 30-35 ℃, and then drying in an oven at 50-60 ℃ for 5-7 hours to obtain oxalic acid modified apatite; the method adopts oxalic acid to modify the apatite, leads the surface of the apatite to have some organic active functional groups such as hydroxyl, carboxyl and the like from the oxalic acid by modification, leads the surface of the apatite to generate more adsorption sites, is beneficial to adsorbing and fixing more metal ions by the apatite, can reduce the content of free metal ions generated by friction in lubricating oil, can effectively change the chemical form and occurrence state of the metal ions in the lubricating oil, reduces the mobility of the metal ions in the lubricating oil, can play a role of passivating the metal ions, thereby playing a role of inhibiting the metal ions from catalyzing oil oxidation, and introduces carboxylic groups on the surface of the apatite by the modification treatment of the oxalic acid, leads the introduced carboxylic groups to show the electrostatic interaction with metal cations, thereby being beneficial to the formation of coordination bonds between the prepared additive and the metal ions, the self-repairing capability of the additive is improved;

2) adding oxalic acid modified apatite into distilled water, stirring for 20-30min at 300r/min of 200-15% to prepare oxalic acid modified apatite dispersion liquid with the mass fraction of 10-15%, then adding 30-50 parts of sodium hydroxide solution, stirring and mixing for 20-30min at room temperature at the rotating speed of 50-100r/min, then carrying out suction filtration, adding the washed solid product into ethanol solution, oscillating and dispersing for 15-25min under 300-400W ultrasonic wave, then adding 2-3 parts of organic antioxidant, stirring and reacting for 2-3h at room temperature at the rotating speed of 80-130r/min, then adding 0.5-0.8 part of amine compound, reacting for 5-7h at 50-60 ℃, centrifugally separating after the reaction is finished, washing the solid product, purifying, and purifying, Drying to obtain modified apatite modified by organic antioxidant; the organic antioxidant is used as a modifier, and is connected to the surface of the oxalic acid modified apatite by an in-situ modification method, so that the dispersion uniformity of the oxalic acid modified apatite in organic matters can be improved due to the existence of the organic antioxidant, and the inhibition effect of the organic antioxidant on the oxidation of oil products can be improved by the passivation effect of the oxalic acid modified apatite on metal ions, so that the purposes of prolonging the use of the oil products and protecting machines are achieved;

3) adding 2-5 parts of polyvinyl alcohol into deionized water, stirring for 30-40min at a rotation speed of 100-150r/min in a greenhouse, then placing the mixture in an oven at a temperature of 80-90 ℃ until the mixture is completely dissolved to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 5-8%, then adding 1-3 parts of borax into deionized water, heating to 40-50 ℃, stirring and dissolving to prepare a borax aqueous solution with a mass fraction of 2-4%, then mixing and stirring the polyvinyl alcohol aqueous solution and the borax aqueous solution uniformly at a temperature of 70-80 ℃, preserving heat for 20-30min, adding 1-2 parts of tributyl phosphate, cooling to 50-60 ℃, and reacting for 3-5h to prepare a modified polyvinyl alcohol aqueous solution; defoaming by utilizing tributyl phosphate, and forming a cross-linked supramolecular structure by adding borax into a polyvinyl alcohol aqueous solution through a sufficient cross-linking reaction and introducing dynamic boric acid diol and an ester bond between polyvinyl alcohol chains, so that the synergistic effect of non-covalent bond hydrogen bond interaction can be improved, the interaction force between the hydrogen bond and metal ions is enhanced, and the self-repairing capability of the prepared additive is improved;

4) 3-5 parts of carbon nano tube is taken, is dried after acidizing, can improve the dispersibility of the carbon nano tube after acidizing, enables the carbon nano tube not to be easily agglomerated, enhances the interaction between the carbon nano tube and a matrix, and is beneficial to the subsequent polymerization reaction; then fully mixing the activated carbon nano tube with potassium hydroxide powder in a mortar according to the weight ratio of 1:4, then placing the mixture in a ceramic boat, placing the ceramic boat in a tube furnace, firstly introducing nitrogen at normal temperature at the flow rate of 150-; the specific surface area and the pore volume of the carbon nano tube can be obviously improved by activating the carbon nano tube, and the reaction activity of the carbon nano tube is improved, so that the adsorption and fixation of the prepared additive to metal ions are enhanced;

5) taking 10-15 parts of hexamethylcyclotrisiloxane and 1-2 parts of 1, 3-bis (3-aminopropyl) -1,1,3, 3-tetramethyldisiloxane, mixing, adding 0.1-0.3 part of tetramethylammonium hydroxide, placing in a dry reactor filled with nitrogen, reacting for 10-15h at the temperature of 100 plus-120 ℃, then heating to the temperature of 180 plus-200 ℃, preserving heat for 10-30min, then cooling to the temperature of 150 plus-160 ℃, vacuumizing to 10-20kPa, adding the obtained sticky liquid into a modified polyvinyl alcohol aqueous solution, then adding 0.05-0.1 part of N, N-dimethyl bisacrylamide, 0.03-0.05 part of potassium persulfate, modified apatite modified by an organic antioxidant and an activated carbon nanotube, stirring for 1-2h at the rotation speed of 130 plus-180 r/min, adding the solution into a reactor, introducing nitrogen for 20-30min, heating to 80-90 deg.C, reacting at constant temperature for 3-5h, drying the product in a 50-60 deg.C oven to constant weight, pulverizing, and grinding to obtain additive with average particle diameter of 10-15 um; using tetramethyl ammonium hydroxide as catalyst, making hexamethylcyclotrisiloxane undergo the process of ring-opening reaction to form amino-terminated polydimethylsiloxane, then grafting the modified polyethylene glycol and the modified polyethylene glycol to a side chain of polydimethylsiloxane through graft polymerization, thereby forming the modified organic silicon additive with self-repairing function by taking the polydimethylsiloxane as the main chain, the siloxane main chain contained in the additive has excellent chain movement capability and can move to the defect position on the metal surface under the driving action of mechanical external force, and the coordination bonds and hydrogen bonds in the molecular chain are broken along with the rise of the temperature of the lubricating oil and under the action of external force, meanwhile, new coordination bonds and hydrogen bonds can be formed between the broken partial coordination bonds and the metal ions at the metal surface defects, so that the self-repairing of the metal surface defects is realized; by introducing the modified polyethylene glycol, the density of dynamic hydrogen bonds on the side chain of the modified organic silicon additive can be improved, so that the self-repairing capability of the modified organic silicon additive is improved; the added activated carbon nano tubes are introduced into a cross-linked network structure of the modified organic silicon additive through a cross-linking reaction, so that the mechanical property of the modified organic silicon additive can be well improved, the hardness of the metal surface is improved after self-repairing, and the pore volume of the activated carbon nano tubes is increased, so that the adsorption and fixation effects of the additive on free metal ions in lubricating oil are improved, and the antioxidant effect of the lubricating oil can be improved; the added modified apatite modified by the organic antioxidant can be used as a carrier, so that the antioxidant requirement under severe working conditions can be met, oil products can be prevented from being oxidized, and the prepared additive can be uniformly dispersed in lubricating oil by utilizing the excellent dispersion stability of the organic antioxidant in the oil products.

Preferably, the preparation method of the antioxidant system self-repairing lubricating oil additive comprises the step 1), wherein the average particle size of the apatite powder is 20-50 um.

Preferably, the preparation method of the antioxidant system self-repairing lubricating oil additive comprises the following steps of 2), wherein the mass fraction of the sodium hydroxide solution is 15-20%; the organic antioxidant is hindered phenol antioxidant and is selected from any one of 2, 6-tertiary butyl-4-methylphenol, bis (3, 5-tertiary butyl-4-hydroxyphenyl) thioether and 3- (3, 5-di-tertiary butyl-4-hydroxyphenyl) propionic acid; the amine compound is selected from any one of tetraethylammonium hydroxide, tetrabutylammonium hydroxide and tetrapropylammonium hydroxide.

Preferably, the preparation method of the antioxidant system self-repairing lubricating oil additive, wherein in the step 4), the diameter of the carbon nanotube is 10-20nm, and the length of the carbon nanotube is 10-20 um.

Preferably, the preparation method of the antioxidant system self-repairing lubricating oil additive, wherein in the step 4), the carbon nanotube acidification treatment process is as follows: adding carbon nanotubes into concentrated nitric acid with the mass fraction of 80-85% according to the solid-to-liquid ratio of 1:30-50g/ml, soaking at 30-35 ℃ for 5-6h, then performing ultrasonic dispersion treatment at 60-70 ℃ for 20-25h at 300-500W, cooling, performing centrifugal separation, washing with distilled water until the filtrate is neutral, and drying at 50-60 ℃ to constant weight.

Compared with the prior art, the invention has the following advantages:

the lubricating oil additive prepared by the invention takes siloxane as a main chain, modified polyethylene glycol as a side chain, and modified apatite modified by activated carbon nano tubes and organic antioxidants are added at the same time, and the lubricating oil additive is formed by a crosslinking reaction, has good compatibility with lubricating oil, can uniformly disperse and stably exist in the lubricating oil, can self-repair defects on the metal surface caused by friction, can improve the oxidation resistance of the lubricating oil, can effectively prevent the lubricating oil from losing efficacy due to oxidation, and well prolongs the service life of the lubricating oil.

Detailed Description

The present invention will be further described with reference to specific embodiments.