Chlorinated paraffin / carbon nanotube composite material as well as preparation method and application thereof
By preparing chlorinated paraffin/carbon nanotube composite materials, the problem of poor thermal stability of chlorinated paraffin was solved, its application performance in extreme pressure anti-wear field was improved, and the effects of high thermal stability and low friction coefficient were achieved.
Patent Information
- Application Number
- CN202511087454.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-05
- Publication Date
- 2025-12-05
AI Technical Summary
Chlorinated paraffins have poor thermal stability during extreme pressure friction and are prone to producing HCl, which can lead to corrosion of metal surfaces, thus limiting their application in extreme pressure anti-wear applications.
By preparing chlorinated paraffin/carbon nanotube composite materials, the active chlorine content in chlorinated paraffin is reduced, improving thermal stability. Furthermore, by grafting methylimidazolium groups and molybdenum disulfide layers onto the carbon nanotube surface of the molybdenum layer, a friction mode combining sliding and rolling friction is formed, thereby reducing the coefficient of friction.
It improves the thermal stability and wear resistance of chlorinated paraffin, reduces the coefficient of friction, and enhances the protective effect on metals, making it suitable for extreme pressure anti-wear agents.
Smart Images
Figure CN121064489A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chlorinated paraffin technology, and in particular to a chlorinated paraffin / carbon nanotube composite material, its preparation method, and its application. Background Technology
[0002] Chlorinated paraffin is an organic compound that can be used as an extreme pressure anti-wear agent, flame retardant, and plasticizer. When used as an extreme pressure anti-wear agent, chlorinated paraffin is initially adsorbed onto the surface of the friction pair. As the load on the contact surface increases and the temperature rises due to friction, the chlorinated compound decomposes or the C-Cl chemical bond breaks to generate chlorine atoms or HCl, which then react with the metal surface of the friction pair to form a FeCl2 or FeCl3 protective film, exhibiting anti-wear and extreme pressure effects.
[0003] The chlorine atoms in chlorinated paraffin exhibit the highest reactivity when located at the ends of aliphatic hydrocarbons, followed by lower reactivity when located in the middle of the carbon chain. Because extreme pressure friction generates a large amount of heat, and chlorinated paraffin has poor thermal stability, it produces a large amount of HCl at high temperatures, easily causing extensive corrosion of metal surfaces, thus limiting its application in extreme pressure anti-wear applications. Summary of the Invention
[0004] Based on the technical problems existing in the background technology, the present invention proposes a chlorinated paraffin / carbon nanotube composite material, its preparation method and application. The present invention has a very low coefficient of friction, good thermal stability, and low corrosivity to metals, and can be used as an extreme pressure anti-wear agent.
[0005] This invention proposes a method for preparing chlorinated paraffin / carbon nanotube composite material, comprising the following steps: reacting carbon nanotubes grafted with epoxy groups with 2-aminomethyl-1-methylimidazole in a primary reaction to obtain intermediate 1 grafted with methylimidazole groups; reacting intermediate 1 grafted with methylimidazole groups with chlorinated paraffin in a secondary reaction, and then adding N-methylimidazole to continue the reaction to obtain chlorinated paraffin / carbon nanotube composite material.
[0006] The chlorine content of the above-mentioned chlorinated paraffin is 42-52 wt%.
[0007] Preferably, the surface of the carbon nanotubes is coated with a molybdenum disulfide layer.
[0008] The preparation method of the above-mentioned carbon nanotubes is as follows: the ethanol dispersion of carboxylated carbon nanotubes and ammonium tetrathiomolybdate are ultrasonically dispersed, heated to 400-450℃ and kept at 1-1.5h in a hydrogen atmosphere, then heated to 800-850℃ and kept at 3.5-4h, and cooled to room temperature to obtain carbon nanotubes with a molybdenum disulfide layer on their surface.
[0009] In the above method for preparing carbon nanotubes, ultrasonic dispersion is performed for 2-3 hours; the weight ratio of carboxylated carbon nanotubes to ammonium tetrathiomolybdate is 1:7-8.
[0010] This invention grafts epoxy groups onto carbon nanotubes coated with a molybdenum disulfide layer, then reacts with the amino group in 2-aminomethyl-1-methylimidazole to successfully graft methylimidazole groups onto the carbon nanotubes. The methylimidazole groups then react with the active chlorine in chlorinated paraffin to form a salt, thereby grafting carbon nanotubes onto the chlorinated paraffin. The remaining active chlorine in the chlorinated paraffin then reacts with methylimidazole to form a salt, introducing methylimidazole groups into the chlorinated paraffin.
[0011] This invention reduces the content of active chlorine in chlorinated paraffin through reaction, thereby improving its thermal stability. Furthermore, the grafted carbon nanotubes enhance thermal conductivity, further improving the thermal stability of the composite material. This prevents the thermal decomposition of chlorinated paraffin, which produces large amounts of HCl, from corroding metal components. Additionally, the grafted methylimidazolium groups endow the composite material with certain ionic liquid properties, improving the dispersibility of chlorinated paraffin and carbon nanotubes in lubricating oil, thus enhancing wear resistance. Moreover, the introduction of methylimidazolium groups allows the carbon nanotubes to interact with their coaxially coated molybdenum disulfide layer, forming a friction pattern that combines sliding and rolling friction. This significantly reduces the coefficient of friction, improves wear resistance, and makes it suitable for use as an extreme pressure anti-wear agent.
[0012] Preferably, the carbon nanotubes grafted with epoxy groups are obtained by grafting and modifying carbon nanotubes with a silane coupling agent containing epoxy groups.
[0013] The aforementioned silane coupling agents containing epoxy groups can be, for example, γ-glycidoxypropyltrimethoxysilane. In the aforementioned carbon nanotubes grafted with epoxy groups, the content of epoxy groups is 1-1.5 mmol / g.
[0014] Preferably, the temperature of the single reaction is 60-70℃ and the time is 2-4h.
[0015] Preferably, the molar ratio of epoxy groups to 2-aminomethyl-1-methylimidazole in the epoxy-grafted carbon nanotubes is 1:1-1.1.
[0016] Preferably, the temperature of the secondary reaction is 70-80℃ and the time is 36-48h; N-methylimidazole is added and the reaction is continued at this temperature for another 36-48h.
[0017] Preferably, the weight ratio of intermediate 1 grafted with a methylimidazole group, chlorinated paraffin, and N-methylimidazole is 8-12:50:50.
[0018] The solvent for the first reaction is methanol; the solvent for the second reaction is water.
[0019] All of the above water is deionized water.
[0020] The present invention also proposes a chlorinated paraffin / carbon nanotube composite material, which is prepared according to the above-described preparation method of the chlorinated paraffin / carbon nanotube composite material.
[0021] The present invention also proposes the application of the above-mentioned chlorinated paraffin / carbon nanotube composite material in extreme pressure anti-wear agents.
[0022] The present invention also proposes a lubricating oil whose raw materials include: base oil and extreme pressure anti-wear agent, wherein the extreme pressure anti-wear agent is the above-mentioned chlorinated paraffin / carbon nanotube composite material.
[0023] The extreme pressure anti-wear agent content in the above-mentioned lubricating oil is 0.8-1.2 wt%.
[0024] The aforementioned base oils can be base oils 150N, 500N, etc.
[0025] The above-mentioned lubricating oils may also contain: corrosion inhibitors, antioxidants, rust inhibitors, etc.
[0026] This invention selects intermediate 1 and N-methylimidazole grafted with methylimidazole groups to undergo a salt-forming reaction with the active chlorine in chlorinated paraffin. On the one hand, this reduces the active chlorine content and improves its thermal stability, and the grafted carbon nanotubes can improve thermal conductivity, further enhancing the thermal stability of chlorinated paraffin. On the other hand, the grafted carbon nanotubes coated with molybdenum disulfide and methylimidazole groups give the composite material certain ionic liquid properties. The three factors work together to significantly reduce the coefficient of friction and improve its wear resistance, making the composite material usable as an extreme pressure anti-wear agent. Attached Figure Description
[0027] Figure 1 This is a typical morphology diagram of the surface of the lubricating oil prepared in Example 3 after friction.
[0028] Figure 2 This is a typical morphology diagram of the surface of the lubricating oil prepared for Comparative Example 2 after friction. Detailed Implementation
[0029] The technical solution of the present invention will be described in detail below through specific embodiments. However, it should be clearly stated that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention.
[0030] Example 1
[0031] A method for preparing a chlorinated paraffin / carbon nanotube composite material includes the following steps: The ethanol dispersion of carboxylated carbon nanotubes was mixed with ammonium tetrathiomolybdate to achieve a weight ratio of 1:7.5. The mixture was ultrasonically dispersed for 2.5 h, and then hydrogen gas was introduced to purge the air. In the hydrogen atmosphere, the temperature was increased to 430 °C at a rate of 10 °C / min and held for 1.5 h. Then, the temperature was increased to 830 °C at a rate of 10 °C / min and held for 4 h. The mixture was then cooled to room temperature to obtain carbon nanotubes with a molybdenum disulfide layer on their surface. The carbon nanotubes with molybdenum disulfide coating were mixed with an ethanol aqueous solution of 5 wt% γ-glycidyl etheroxypropyltrimethoxysilane, ultrasonically dispersed for 30 min, then heated to 70 °C and kept at that temperature for 2 h, filtered, washed, and dried to obtain carbon nanotubes grafted with epoxy groups. The content of epoxy groups was found to be 1 mmol / g. Epoxy-grafted carbon nanotubes and 2-aminomethyl-1-methylimidazole were added to methanol and stirred until the molar ratio of epoxy groups in the epoxy-grafted carbon nanotubes to 2-aminomethyl-1-methylimidazole was 1:1. The mixture was heated to 60°C and kept at that temperature for 4 hours. After filtration, washing, and drying, intermediate 1 with methylimidazole grafted on was obtained. Then, intermediate 1 grafted with methylimidazole groups was uniformly dispersed in water, and chlorinated paraffin with a chlorine content of 42wt% was added and mixed. The mixture was heated to 70℃ and carried out a second reaction for 48h. Then, N-methylimidazole was added and mixed. The reaction was continued at the temperature for another 48h. The mixture was then washed with ethyl acetate and water in sequence, and then dried under vacuum at 50℃ to obtain chlorinated paraffin / carbon nanotube composite material. The weight ratio of intermediate 1 grafted with methylimidazole groups, chlorinated paraffin, and N-methylimidazole was 8:50:50.
[0032] Example 2
[0033] A method for preparing a chlorinated paraffin / carbon nanotube composite material includes the following steps: Carbon nanotubes grafted with epoxy groups were prepared according to the method of Example 1; Epoxy-grafted carbon nanotubes and 2-aminomethyl-1-methylimidazole were added to methanol and stirred until the molar ratio of epoxy groups in the epoxy-grafted carbon nanotubes to 2-aminomethyl-1-methylimidazole was 1:1.1. The mixture was heated to 70°C and kept at that temperature for 2 hours. After filtration, washing, and drying, intermediate 1 with methylimidazole grafted on was obtained. Then, intermediate 1 grafted with methylimidazole groups was uniformly dispersed in water, and chlorinated paraffin with a chlorine content of 42wt% was added and mixed. The mixture was heated to 80℃ and carried out a second reaction for 36h. Then, N-methylimidazole was added and mixed. The reaction was continued at the temperature for another 36h. The mixture was then washed with ethyl acetate and water in sequence, and then dried under vacuum at 50℃ to obtain chlorinated paraffin / carbon nanotube composite material. The weight ratio of intermediate 1 grafted with methylimidazole groups, chlorinated paraffin, and N-methylimidazole was 12:50:50.
[0034] Example 3
[0035] A method for preparing a chlorinated paraffin / carbon nanotube composite material includes the following steps: Carbon nanotubes grafted with epoxy groups were prepared according to the method of Example 1; Epoxy-grafted carbon nanotubes and 2-aminomethyl-1-methylimidazole were added to methanol and stirred until the molar ratio of epoxy groups in the epoxy-grafted carbon nanotubes to 2-aminomethyl-1-methylimidazole was 1:1.05. The mixture was heated to 65°C and kept at that temperature for 3 hours. After filtration, washing, and drying, intermediate 1 with methylimidazole grafted on was obtained. Then, intermediate 1 grafted with methylimidazole groups was uniformly dispersed in water, and chlorinated paraffin with a chlorine content of 42wt% was added and mixed. The mixture was heated to 75℃ and carried out a second reaction for 40h. Then, N-methylimidazole was added and mixed. The reaction was continued at the temperature for another 40h. The mixture was then washed with ethyl acetate and water in sequence, and then dried under vacuum at 50℃ to obtain chlorinated paraffin / carbon nanotube composite material. The weight ratio of intermediate 1 grafted with methylimidazole groups, chlorinated paraffin, and N-methylimidazole was 10:50:50.
[0036] Comparative Example 1 An extreme pressure anti-wear agent is prepared by the following method: mixing chlorinated paraffin with a chlorine content of 42wt% and water, adding N-methylimidazole and mixing, heating to 75℃, keeping the temperature for 40h, washing with ethyl acetate and water in sequence, and then drying under vacuum at 50℃ to obtain the extreme pressure anti-wear agent, wherein the weight ratio of chlorinated paraffin and N-methylimidazole is 50:50.
[0037] Comparative Example 2 An extreme pressure anti-wear agent, the preparation method of which includes: Intermediate 1 grafted with a methylimidazolium group was prepared according to the method of Example 3; Then, the intermediate 1 grafted with methylimidazolium groups was uniformly dispersed in water, and chlorinated paraffin with a chlorine content of 42wt% was added and mixed. The mixture was heated to 75℃ and reacted for 40h. Then, it was washed with ethyl acetate and water in sequence, and then dried under vacuum at 50℃ to obtain an extreme pressure anti-wear agent. The weight ratio of the intermediate 1 grafted with methylimidazolium groups to chlorinated paraffin was 10:50.
[0038] Comparative Example 3 An extreme pressure anti-wear agent, the preparation method of which includes: Carboxylated carbon nanotubes were mixed with an ethanol-water solution of 5 wt% γ-glycidoxypropyltrimethoxysilane, ultrasonically dispersed for 30 min, then heated to 70 °C and kept at that temperature for 2 h, filtered, washed, and dried to obtain carbon nanotubes grafted with epoxy groups. The content of epoxy groups was found to be 1.5 mmol / g. Epoxy-grafted carbon nanotubes and 2-aminomethyl-1-methylimidazole were added to methanol and stirred until the molar ratio of epoxy groups in the epoxy-grafted carbon nanotubes to 2-aminomethyl-1-methylimidazole was 1:1.05. The mixture was heated to 65°C and kept at that temperature for 3 hours. After filtration, washing, and drying, intermediate 1 with methylimidazole grafted on was obtained. Then, intermediate 1 grafted with methylimidazole groups was uniformly dispersed in water, and chlorinated paraffin with a chlorine content of 42wt% was added and mixed. The mixture was heated to 75℃ and carried out a second reaction for 40h. Then, N-methylimidazole was added and mixed. The reaction was continued at the temperature for another 40h. The mixture was then washed with ethyl acetate and water in sequence, and then dried under vacuum at 50℃ to obtain chlorinated paraffin / carbon nanotube composite material. The weight ratio of intermediate 1 grafted with methylimidazole groups, chlorinated paraffin, and N-methylimidazole was 10:50:50.
[0039] The products from Examples 1-3 and Comparative Examples 1-3 were used as extreme pressure anti-wear agents to formulate lubricating oils. The raw materials of the lubricating oils were recorded by weight percentage as follows: 150N base oil 99wt%, extreme pressure anti-wear agent 1wt%. The performance of each group of lubricating oils was tested, and the results are shown in Table 1.
[0040] The tribological and extreme pressure properties of the oil samples were tested using a four-ball friction testing machine. Each group of lubricating oils was dripped onto the ball-disc contact area, and tests were conducted according to GB / T12583-1998. The wear scar diameter was tested at room temperature, with a rotation speed of 1450 r / min and a test duration of 30 min; the coefficient of friction was tested at 500 N. All test balls were GCr15 bearing steel balls with a diameter of 12.7 mm and a Rockwell hardness of HRC59-61.
[0041] The corrosion resistance of the lubricating oil was tested according to SH / T 0195. The storage conditions were 100℃ for 8 hours, and the test sample was No. 45 steel.
[0042]
[0043] As can be seen from Table 1, the chlorinated paraffin / carbon nanotube composite material of the present invention can be used as an extreme pressure anti-wear agent to improve the high temperature resistance and corrosion resistance of chlorinated paraffin, reduce the coefficient of friction, and improve the extreme pressure anti-wear performance.
[0044] Figure 1 This is a typical morphology diagram of the surface of the lubricating oil prepared in Example 3 after friction.
[0045] Figure 2 This is a typical morphology diagram of the surface of the lubricating oil prepared for Comparative Example 2 after friction.
[0046] Depend on Figure 1-2 It can be seen that the friction surface grooves formed by the lubricating oil prepared in Example 3 are shallower, while the friction surface grooves formed by the lubricating oil prepared in Comparative Example 2 are deeper and the wear is more severe.
[0047] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A method for preparing a chlorinated paraffin / carbon nanotube composite material, characterized in that, The process includes the following steps: a carbon nanotube grafted with epoxy groups reacts with 2-aminomethyl-1-methylimidazole in a primary reaction to obtain intermediate 1 grafted with methylimidazole groups; intermediate 1 grafted with methylimidazole groups is reacted with chlorinated paraffin in a secondary reaction, and then N-methylimidazole is added to continue the reaction to obtain a chlorinated paraffin / carbon nanotube composite material.
2. The preparation method of the chlorinated paraffin / carbon nanotube composite material according to claim 1, characterized in that, The surface of the carbon nanotubes is coated with a molybdenum disulfide layer.
3. The preparation method of the chlorinated paraffin / carbon nanotube composite material according to claim 1, characterized in that, Epoxy-coated carbon nanotubes are obtained by grafting carbon nanotubes with a silane coupling agent containing epoxy groups.
4. The preparation method of the chlorinated paraffin / carbon nanotube composite material according to claim 1, characterized in that, The temperature for one reaction is 60-70℃, and the time is 2-4 hours.
5. The method for preparing the chlorinated paraffin / carbon nanotube composite material according to claim 1, characterized in that, In carbon nanotubes grafted with epoxy groups, the molar ratio of epoxy groups to 2-aminomethyl-1-methylimidazole is 1:1-1.
1.
6. The method for preparing the chlorinated paraffin / carbon nanotube composite material according to claim 1, characterized in that, The secondary reaction was carried out at a temperature of 70-80℃ for 36-48 hours; N-methylimidazole was added and the reaction was continued at this temperature for another 36-48 hours.
7. The method for preparing the chlorinated paraffin / carbon nanotube composite material according to claim 1, characterized in that, The weight ratio of intermediate 1 grafted with a methylimidazole group, chlorinated paraffin, and N-methylimidazole is 8-12:50:
50.
8. A chlorinated paraffin / carbon nanotube composite material, characterized in that, The chlorinated paraffin / carbon nanotube composite material was prepared according to any one of claims 1-7.
9. The application of the chlorinated paraffin / carbon nanotube composite material as described in claim 8 in extreme pressure anti-wear agents.
10. A lubricating oil, characterized in that, Its raw materials include: base oil and extreme pressure anti-wear agent, wherein the extreme pressure anti-wear agent is the chlorinated paraffin / carbon nanotube composite material as described in claim 8.