A preparation method of a carbon nanotube MXene polytetrafluoro wax polyurea resin composite coating

Abstract

A preparation method of a carbon nanotube MXene polytetrafluoro wax polyurea resin composite coating, a solution is prepared with a ferrocene mass, ethylenediamine volume and ethanol volume ratio of 0.5g:10mL:40-60mL, carbon nanotubes are in-situ grown on 0.1-0.3g MXene nanosheets by dropwise adding under a nitrogen atmosphere at 800-1000 DEG C to obtain CNTs / MXene; a PFW@PDA is obtained by stirring with a polytetrafluoro wax mass, dopamine hydrochloride mass and Tris buffer volume ratio of 1g:1g:50-75mL, followed by centrifugation, separation and washing; a mixed slurry is obtained by stirring after mixing with a CNTs / MXene, PFW@PDA and polyurea resin slurry mass ratio of 1:10:50-200; the composite coating is obtained by coating on a steel sheet and drying. The method can obtain a composite coating with good mechanical strength, excellent lubricating performance and high wear resistance.

Description

Technical Field

[0001] This invention belongs to the field of functional materials technology, specifically relating to a method for preparing a carbon nanotube MXene polytetrafluoroethylene wax polyurea resin composite coating. Background Technology

[0002] Friction and wear are ubiquitous in daily life, causing damage, malfunctions, and shortened lifespans of numerous components, as well as increased fuel consumption, leading to a serious waste of resources and energy. Friction and wear are always intertwined; wear not only results in significant energy loss and damage to parts, causing mechanical failure and malfunction, but also wastes considerable human and material resources and can even endanger human health. Furthermore, wear generates a large amount of "waste," placing immense pressure on the environment. Polymer-based wear-resistant composite materials not only possess excellent properties such as friction reduction and wear resistance, but also exhibit superior characteristics such as high specific strength and ease of processing. Selecting suitable resin-based wear-resistant composite materials can not only solve many technical problems that are difficult to overcome using metal materials, improving the service life and safety of machinery and equipment, and reducing the occurrence of safety accidents, but also improve the technical indicators of machine structures, thereby saving significant amounts of precious metal materials, reducing the overall weight of machinery and equipment, and lowering overall manufacturing costs.

[0003] The commonly used resin bases for polymer solid lubricant coatings are polyurea resin, phenolic resin, silicone resin, polyurethane, etc. Polyurea resin has a leading position in real-world applications due to its good adhesion, corrosion resistance and chemical stability, as well as its low curing shrinkage and easy processing. It has also become a key material for scientific research.

[0004] The excellent physicochemical properties of polyurea resin, as described above, ensure its versatility across various fields, leading to its widespread application. However, the high brittleness and poor wear resistance of pure polyurea resin after curing severely limit its applications. To broaden its development potential, researchers have consistently focused on reinforcing and modifying polyurea resin. Physical methods are the most effective and commonly used approach to improve the tribological properties of polyurea coatings. These methods involve adding additives to the polyurea resin coating matrix to improve its friction and wear performance. For example, adding solid lubricants can effectively increase the coating's hardness, stiffness, and load-bearing capacity, thereby enhancing the composite material's creep and compression resistance, ultimately improving the coating's frictional properties. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a method for preparing a carbon nanotube / MXene / PTFE wax / polyurea resin composite coating. This method is simple to prepare, has low manufacturing cost, is environmentally friendly and pollution-free, and can obtain a carbon nanotube / MXene / PTFE wax / polyurea composite coating with good mechanical strength, excellent lubrication performance, high wear resistance and rapid self-healing properties.

[0006] This invention provides a method for preparing a carbon nanotube MXene polytetrafluoroethylene wax-polyurea resin composite coating, comprising the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol (volume ratio) of 0.5 g: 10 mL: 40–60 mL. Slowly add the prepared solution dropwise onto 0.1–0.3 g of MXene nanosheets under a nitrogen atmosphere at 800–1000 °C to grow carbon nanotubes in situ, thus obtaining CNTs / MXene. Step 2: Add polytetrafluoroethylene wax and dopamine hydrochloride to Tris buffer at a ratio of 1g:1g:50-75mL and stir continuously. After stirring, centrifuge, separate, and wash with distilled water 3-5 times to obtain polydopamine-functionalized polytetrafluoroethylene wax PFW@PDA. Step 3: Mix CNTs / MXene, PFW@PDA, and polyurea resin slurry at a ratio of 1:10:50-200 and stir at 900 rpm for 20-24 hours to obtain the mixed slurry. Step 4: Coat the mixed slurry obtained in Step 3 onto a steel sheet and dry it at room temperature for 24 to 48 hours to obtain a self-lubricating carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating.

[0007] As a preferred embodiment, in step two, a homogeneous solution of 2.4465g Tris and 0.4221g concentrated hydrochloric acid is added to 300mL of distilled water; the stirring time is 20-24 hours; and the centrifugation speed is 8000rpm.

[0008] As a preferred embodiment, in step three, a curing agent is also added, wherein the mass ratio of the polyurea resin slurry to the curing agent is 1:2 to 3.

[0009] As a preferred embodiment, in step four, the steel sheet undergoes pretreatment before coating. The pretreatment method is as follows: The steel sheet was cleaned 3 to 5 times using a mixed solution of ethanol and acetone in a 1:1 mass ratio.

[0010] Compared with the prior art, the present invention has the following technical effects: 1. The preparation method of the present invention is very simple and does not require any extra impurity removal steps. The solvent used in the entire preparation process is green, environmentally friendly and pollution-free. It only requires simple etching of MXene, growth of carbon nanotubes on MXene by chemical vapor deposition, mixing of functionalized polytetrafluoroethylene wax and carbon nanotube / MXene powder with polyurea resin slurry and stirring thoroughly, then coating it on a pre-made steel sheet, and then curing at room temperature to obtain a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating. 2. The composite coating obtained by the present invention exhibits high mechanical strength, excellent self-lubricating properties, high wear resistance, and excellent self-healing properties.

[0011] 3. The synthesis process of this invention is simple and does not require overly complicated synthesis steps; 4. The raw materials of this invention are widely available, the preparation process is simple, the cost is low, and it is environmentally friendly and pollution-free. The prepared carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea composite coating has good mechanical strength, excellent lubrication performance, high wear resistance, and rapid self-healing performance. Attached Figure Description

[0012] Figure 1 This is a SEM microstructure image of the MXene prepared in this invention; Figure 2 Here is a SEM microstructure image of the CNTs / MXene prepared in this invention; Figure 3 This is a SEM microstructure image of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in this invention. Figure 4 This is a macroscopic photograph of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared according to the present invention; Figure 5 This is a graph showing the coefficient of friction in a dry friction environment for the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in this invention. Figure 6 This is a friction coefficient diagram of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in this invention under oil friction environment. Figure 7 This is a graph showing the friction coefficient of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in this invention over a long period of time. Figure 8 This is a wear track morphology image of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in this invention. Detailed Implementation

[0013] This invention provides a method for preparing a carbon nanotube MXene polytetrafluoroethylene wax polyurea resin composite coating, comprising the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol in a volume ratio of 0.5 g: 10 mL: 40–60 mL. Slowly add the prepared solution dropwise onto 0.1–0.3 g of MXene nanosheets under a nitrogen atmosphere at 800–1000 °C to grow carbon nanotubes in situ, thus obtaining CNTs / MXene (carbon nanotube / MXene powder). Step 2: Add polytetrafluoroethylene wax and dopamine hydrochloride to Tris buffer at a ratio of 1g:1g:50-75mL and stir continuously. After stirring, centrifuge, separate, and wash with distilled water 3-5 times to obtain polydopamine-functionalized polytetrafluoroethylene wax PFW@PDA. Step 3: Mix CNTs / MXene, PFW@PDA, and polyurea resin slurry at a ratio of 1:10:50-200 and stir at 900 rpm for 20-24 hours to obtain the mixed slurry. Step 4: Coat the mixed slurry obtained in Step 3 onto a steel sheet and dry it at room temperature for 24 to 48 hours to obtain a self-lubricating carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating.

[0014] As a preferred embodiment, in step two, a homogeneous solution of 2.4465g Tris and 0.4221g concentrated hydrochloric acid is added to 300mL of distilled water; the stirring time is 20-24 hours; and the centrifugation speed is 8000rpm.

[0015] As a preferred embodiment, in step three, a curing agent is also added, wherein the mass ratio of the polyurea resin slurry to the curing agent is 1:2 to 3.

[0016] As a preferred embodiment, in step four, the steel sheet undergoes pretreatment before coating. The pretreatment method is as follows: The steel sheet was cleaned 3 to 5 times using a mixed solution of ethanol and acetone in a 1:1 mass ratio.

[0017] Compared with the prior art, the present invention has the following technical effects: 1. The preparation method of the present invention is very simple and does not require any extra impurity removal steps. The solvent used in the entire preparation process is green, environmentally friendly and pollution-free. It only requires simple etching of MXene, growth of carbon nanotubes on MXene by chemical vapor deposition, mixing of functionalized polytetrafluoroethylene wax and carbon nanotube / MXene powder with polyurea resin slurry and stirring thoroughly, then coating it on a pre-made steel sheet, and then curing at room temperature to obtain a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating. 2. The composite coating obtained by the present invention exhibits high mechanical strength, excellent self-lubricating properties, high wear resistance, and excellent self-healing properties.

[0018] 3. The synthesis process of this invention is simple and does not require overly complicated synthesis steps; 4. The raw materials of this invention are widely available, the preparation process is simple, the cost is low, and it is environmentally friendly and pollution-free. The prepared carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea composite coating has good mechanical strength, excellent lubrication performance, high wear resistance, and rapid self-healing performance.

[0019] The present invention will be further described below with reference to specific embodiments: Example

[0020] A method for preparing a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating includes the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol (volume ratio) at 0.5 g: 10 mL: 40 mL. Slowly add the prepared solution to 0.1 g MXene nanosheets under a nitrogen atmosphere at 900 °C to grow carbon nanotubes in situ, thus obtaining carbon nanotube / MXene powder (CNTs / MXene). Step 2: Weigh 1g of polytetrafluoroethylene wax and 1g of dopamine hydrochloride and mix with 50mL of Tris buffer. Stir continuously. After the mixture is finished, centrifuge, separate, and wash with distilled water 4 times to obtain polydopamine-functionalized polytetrafluoroethylene wax (PFW@PDA). Step 3: Weigh 0.02g of CNTs / MXene and 0.2g of PFW@PDA and mix them with 1g of polyurea resin slurry, then stir (900rpm) for 20 hours; Step 4: The mixed slurry obtained in Step 3 is uniformly coated onto the steel sheet and dried at room temperature for 36 hours to obtain a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating. Example

[0021] A method for preparing a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating includes the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol (volume ratio) at 0.5 g: 10 mL: 50 mL. Slowly add the prepared solution dropwise onto 0.15 g MXene nanosheets under a nitrogen atmosphere at 800 °C to grow carbon nanotubes in situ, obtaining carbon nanotube / MXene powder (CNTs / MXene). Step 2: Weigh 1g of polytetrafluoroethylene wax and 1g of dopamine hydrochloride and mix them with 60mL of Tris buffer. After stirring continuously, centrifuge, separate, and wash with distilled water 5 times to obtain polydopamine-functionalized polytetrafluoroethylene wax (PFW@PDA). Step 3: Weigh 0.01g of CNTs / MXene and 0.1g of PFW@PDA and mix them with 1g of polyurea resin slurry, then stir (900rpm) for 24 hours; Step 4: The mixed slurry obtained in Step 3 is uniformly coated onto the steel sheet and dried at room temperature for 48 hours to obtain a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating. Example

[0022] A method for preparing a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating includes the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol (volume ratio) at 0.5 g: 10 mL: 50 mL. Slowly add the prepared solution dropwise onto 0.3 g MXene nanosheets under a nitrogen atmosphere at 1000 °C to grow carbon nanotubes in situ, obtaining carbon nanotube / MXene powder (CNTs / MXene). Step 2: Weigh 1g of polytetrafluoroethylene wax and 1g of dopamine hydrochloride and mix with 65mL of Tris buffer. Stir continuously. After the mixture is finished, centrifuge, separate, and wash with distilled water three times to obtain polydopamine-functionalized polytetrafluoroethylene wax (PFW@PDA). Step 3: Weigh 0.02g of CNTs / MXene and 0.2g of PFW@PDA, mix them with 2g of polyurea resin slurry, and stir (900rpm) for 22 hours; Step 4: The mixed slurry obtained in Step 3 is uniformly coated onto the steel sheet and dried at room temperature for 40 hours to obtain a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating. Example

[0023] A method for preparing a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating includes the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol (volume ratio) at 0.5 g: 10 mL: 50 mL. Slowly add the prepared solution dropwise onto 0.2 g MXene nanosheets under a nitrogen atmosphere at 900 °C to grow carbon nanotubes in situ, obtaining carbon nanotube / MXene powder (CNTs / MXene). Step 2: Weigh 1g of polytetrafluoroethylene wax and 1g of dopamine hydrochloride and mix them with 75mL of Tris buffer. After stirring continuously, centrifuge, separate, and wash with distilled water 5 times to obtain polydopamine-functionalized polytetrafluoroethylene wax (PFW@PDA). Step 3: Weigh 0.015g of CNTs / MXene and 0.15g of PFW@PDA and mix them with 1g of polyurea resin slurry, then stir (900rpm) for 24 hours. Step 4: The mixed slurry obtained in Step 3 is uniformly coated onto the steel sheet and dried at room temperature for 48 hours to obtain a carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating.

[0024] like Figure 1 As shown, it is a SEM image of MXene prepared in Example 1. The "accordion" shaped MXene can be clearly observed, which proves that the etching of MXene was successful.

[0025] like Figure 2 As shown, it is a SEM image of CNTs / MXene prepared in Example 1. It can be seen that CNTs grow in situ between MXene layers to form a CNTs / MXene structure, which fully proves the successful preparation of CNTs / MXene.

[0026] like Figure 3 As shown, it is a SEM image of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in Example 4. It can be seen that the surface is uneven, which is caused by the mixture of PFW@PDA and CNTs / MXene, which also confirms that the composite coating was successfully prepared.

[0027] like Figure 4 The image shown is a macroscopic photograph of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in Example 4. The coating surface is free of bubbles and exhibits excellent mechanical strength.

[0028] like Figure 5 As shown, it is a friction coefficient curve of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in Example 4 under dry friction environment. Compared with the polyurea resin coating, its friction coefficient decreased by 79.5%.

[0029] like Figure 6 As shown, it is a friction coefficient curve of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in Example 4 under oil friction environment. Compared with the polyurea resin coating, its friction coefficient decreased by 96.7%.

[0030] like Figure 7 The figure shows the friction coefficient curve of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in Example 4 under long-term friction environment. The composite coating can maintain a stable friction coefficient for a long time.

[0031] like Figure 8 As shown, the wear track morphology of the CNT / MXene / PFW@PDA / polyurea resin composite coating prepared in Example 4 under long-term friction environment is shown. The wear track morphology does not show obvious damage, which proves that the composite coating can be used for a long time.

Claims

1. A method for preparing a carbon nanotube MXene polytetrafluoroethylene wax polyurea resin composite coating, characterized in that, Includes the following steps: Step 1: Prepare a carbon nanotube growth solution by mixing ferrocene (mass), ethylenediamine (volume), and ethanol (volume ratio) of 0.5 g: 10 mL: 40–60 mL. Slowly add the prepared solution dropwise onto 0.1–0.3 g of MXene nanosheets under a nitrogen atmosphere at 800–1000 °C to grow carbon nanotubes in situ, thus obtaining CNTs / MXene. Step 2: Add polytetrafluoroethylene wax and dopamine hydrochloride to Tris buffer at a ratio of 1g:1g:50-75mL and stir continuously. After stirring, centrifuge, separate, and wash with distilled water 3-5 times to obtain polydopamine-functionalized polytetrafluoroethylene wax PFW@PDA. Step 3: Mix CNTs / MXene, PFW@PDA, and polyurea resin slurry at a ratio of 1:10:50-200 and stir at 900 rpm for 20-24 hours to obtain the mixed slurry. Step 4: Coat the mixed slurry obtained in Step 3 onto a steel sheet and dry it at room temperature for 24 to 48 hours to obtain a self-lubricating carbon nanotube / MXene / polytetrafluoroethylene wax / polyurea resin composite coating.

2. The method for preparing a carbon nanotube MXene polytetrafluoroethylene wax polyurea resin composite coating according to claim 1, characterized in that, In step two, prepare a homogeneous solution of 2.4465g Tris and 0.4221g concentrated hydrochloric acid in 300mL of distilled water; stir for 20–24 hours; and centrifuge at 8000rpm.

3. The method for preparing a carbon nanotube MXene polytetrafluoroethylene wax polyurea resin composite coating according to claim 1 or 2, characterized in that, In step three, a curing agent is also added, and the mass ratio of the polyurea resin slurry to the curing agent is 1:2 to 3.

4. The method for preparing a carbon nanotube MXene polytetrafluoroethylene wax polyurea resin composite coating according to claim 3, characterized in that, In step four, the steel sheet undergoes pretreatment before coating. The pretreatment method is as follows: The steel sheet was cleaned 3 to 5 times using a mixed solution of ethanol and acetone in a 1:1 mass ratio.

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