PVDF-basalt-TiO2 double-layer super-hydrophobic coating and preparation method thereof

Abstract

The invention provides a PVDF (Polyvinylidene Fluoride), basalt and TiO2 double-layer super-hydrophobic coating and a preparation method thereof, and belongs to the technical field of coatings. Comprising the following steps: (1) adding nano TiO2 and a titanate coupling agent into a solvent, and heating and stirring for reaction to prepare hydrophobic nano TiO2; (2) adding long-chain alkylsilane and a silane coupling agent with double bonds into ethanol, adding basalt powder, and heating and stirring for reaction to prepare hydrophobic basalt powder; (3) mixing hydrophobic nano TiO2, hydrophobic basalt powder and PVDF (polyvinylidene fluoride), adding the mixture into a solvent, and uniformly stirring and mixing to obtain a hydrophobic coating; and (4) taking an absolute ethyl alcohol solution of epoxy resin as a primer, spraying the primer on the surface of the aluminum plate, curing the primer, then spraying the hydrophobic coating on the surface of the primer, and curing the finish paint to prepare the PVDF-basalt-TiO2 double-layer super-hydrophobic coating, so that the service life of the aluminum power transmission cable is effectively prolonged, the mechanical strength is enhanced, and the performance is improved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a PVDF@basalt@TiO2 double-layer superhydrophobic coating and its preparation method. Background Technology

[0002] With the rapid development of modern industry, aluminum alloys have become a major structural material in industry, second only to steel in terms of application. For aluminum cables, which are currently widely used, when exposed to cold outdoor environments, ice can form on the aluminum surface. The expansion of the ice can compress the aluminum material, causing deformation. The accumulation of ice and snow on the cable surface will increase the extra weight. Especially under freezing rain conditions with alternating rain and snow, the ice layer can be several centimeters thick, far exceeding the cable's design load-bearing capacity, and ultimately leading to breakage.

[0003] Nano-TiO2 possesses excellent mechanical properties and high-temperature resistance, basalt exhibits good UV shielding and stability, and PVDF demonstrates outstanding mechanical properties, high-temperature resistance, and chemical stability. A superhydrophobic coating made from these three raw materials possesses excellent hydrophobicity, as well as superior mechanical and chemical stability. This protects the surface of aluminum power transmission cables from environmental corrosion and frost damage, while also reinforcing the surface of the cables, effectively extending their service life. Furthermore, selecting a suitable primer ensures effective adhesion between the superhydrophobic coating and the aluminum substrate, further enhancing the durability of the aluminum power transmission cables. The spraying method effectively and evenly adheres the coating to the surface of the aluminum power transmission cables, offering a quick, efficient, and simple application process. Summary of the Invention

[0004] The purpose of this invention is to propose a PVDF@basalt@TiO2 double-layer superhydrophobic coating and its preparation method, which can effectively extend the service life of aluminum power transmission cables, avoid surface corrosion caused by icing, rainwater erosion, and dust adhesion, and at the same time improve the aesthetics and long-term durability of aluminum power transmission cables. The superhydrophobic coating not only protects the aluminum power transmission cables but also enhances their surface mechanical strength, thus achieving dual protection and performance improvement for the aluminum power transmission cables.

[0005] The technical solution of this invention is implemented as follows:

[0006] This invention provides a method for preparing a PVDF@basalt@TiO2 bilayer superhydrophobic coating, comprising the following steps:

[0007] (1) Preparation of hydrophobic nano-TiO2: Nano-TiO2 and titanate coupling agent were added to a mixture of ethanol and deionized water, and the mixture was heated and stirred to prepare hydrophobic nano-TiO2.

[0008] (2) Preparation of hydrophobic basalt powder: Long-chain alkyl silane and silane coupling agent with double bond are added to a mixture of ethanol and deionized water, and the mixture is heated and stirred to obtain hydrophobic basalt powder.

[0009] (3) Preparation of hydrophobic coating: Hydrophobic nano-TiO2, hydrophobic basalt powder and PVDF are mixed and added to hexamethylphosphoric triamine solution, stirred and mixed evenly to form a uniformly dispersed slurry, and the hydrophobic coating is obtained.

[0010] (4) Preparation of PVDF@basalt@TiO2 double-layer superhydrophobic coating: Anhydrous ethanol solution of epoxy resin is used as primer. First, the primer is sprayed on the surface of aluminum plate and cured. Then, the hydrophobic coating is sprayed on the primer surface and cured to obtain PVDF@basalt@TiO2 double-layer superhydrophobic coating.

[0011] As a further improvement of the present invention, the mass ratio of nano-TiO2 and titanate coupling agent in step (1) is 10:0.5-1.5, the heating and stirring reaction temperature is 75-85℃, and the time is 2-4h.

[0012] As a further improvement of the present invention, the titanate coupling agent in step (1) is selected from at least one of TC-1, OL-T951, and GR-330.

[0013] As a further improvement of the present invention, the mass ratio of the long-chain alkylsilane, the silane coupling agent with double bonds, and the basalt powder in step (2) is 2-3:1-2:15-20, and the heating and stirring reaction temperature is 40-60℃ and the time is 2-4h.

[0014] As a further improvement of the present invention, the long-chain alkylsilane in step (2) is selected from at least one of octyltriethoxysilane, dodecyltrimethoxysilane, octadecyltrichlorosilane, and octadecyltrimethoxysilane.

[0015] As a further improvement of the present invention, the silane coupling agent with double bonds mentioned in step (2) is selected from at least one of KH570, A151, and A171.

[0016] As a further improvement of the present invention, the mass ratio of hydrophobic nano-TiO2, hydrophobic basalt powder and PVDF in step (3) is 3-5:2-4:6-9.

[0017] As a further improvement of the present invention, the formulation of the primer in step (4) is: the mass ratio of epoxy resin, diethylenetriamine and anhydrous ethanol is 1:0.05-0.1:1.8-2.2, and the curing temperature of the primer is 15-25℃ and the curing time is 1-3h.

[0018] As a further improvement of the present invention, the curing conditions of the topcoat in step (4) are: curing at a temperature of 75-85℃ for 20-40 minutes, and curing at a temperature of 90-100℃ for 20-40 minutes.

[0019] The present invention further protects a PVDF@basalt@TiO2 double-layer superhydrophobic coating prepared by the above preparation method.

[0020] The present invention has the following beneficial effects:

[0021] This invention modifies basalt with long-chain alkyl silanes and silane coupling agents containing double bonds. The long-chain alkyl groups and double bonds enhance the hydrophobicity of the basalt and improve its compatibility with PVDF, thus preventing filler agglomeration and performance degradation. Simultaneously, the basalt also improves the wear resistance and mechanical properties of the coating. The hydrophobic TiO2, on the one hand, forms a micro / nano structure, further enhancing the coating's hydrophobicity; on the other hand, it also exhibits good photocatalytic antibacterial and organic matter degradation effects, improving environmental friendliness and extending service life.

[0022] This invention uses hydrophobic basalt powder and hydrophobic TiO2 as fillers, and modifies them with hydrophobic grafting to construct a micro / nano structure on the coating surface and reduce the surface energy of the material, effectively ensuring the hydrophobic performance of the coating. Simultaneously, PVDF is selected as the solvent: on the one hand, PVDF itself possesses excellent mechanical properties, giving the coating good hardness and strength; on the other hand, both the coating and the solvent have high chemical stability, enabling the coating to exhibit good corrosion resistance. Therefore, compared with traditional coatings, the prepared superhydrophobic coating has significant advantages in both hydrophobicity and durability.

[0023] The superhydrophobic coating prepared by this invention possesses excellent self-cleaning properties, hydrophobicity, wear resistance, weather resistance, corrosion resistance, as well as good physicochemical stability and mechanical properties. Furthermore, through systematic research on the compatibility of different primers, the adhesion between the coating and the aluminum substrate has been significantly enhanced, thus demonstrating broad application prospects in the field of electric power transportation.

[0024] The PVDF@basalt@TiO2 double-layer superhydrophobic coating developed in this invention effectively solves the problems of surface icing, rainwater erosion, and difficulty in self-cleaning due to dust adhesion in winter for aluminum power transmission cables, as well as the insufficient mechanical properties and wear resistance of ordinary hydrophobic coatings. It not only endows aluminum power transmission cables with de-icing, moisture-proof, and self-cleaning functions, but also enhances the strength and durability of the substrate through its excellent mechanical properties, thereby extending the service life of aluminum power transmission cables and improving their appearance. This superhydrophobic coating protects the aluminum substrate while also improving surface mechanical strength and wear resistance. By adjusting the mass ratio of the two fillers and the mass ratio of filler to solvent, the coating performance can be further optimized to obtain a superhydrophobic coating with optimal overall performance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 The photograph shows the specimen manufactured according to the process and its contact angle, which is 155°.

[0027] Figure 2 This is a photograph of an adhesive tape peeling experiment.

[0028] Figure 3 This is a photo of a sandpaper abrasion experiment.

[0029] Figure 4 Photographs of the specimen from the pencil scratch experiment; the coating hardness grade is 3H.

[0030] Figure 5 These are before-and-after photos from a 10-hour salt spray test.

[0031] Figure 6 Comparative photographs of coated copper plates and bare copper plates subjected to a freezing delay test at -10℃ are shown. Photo a shows the freezing process of the bare copper plate, photo b shows the freezing process of the coated copper plate, photo c shows the melting process of the bare copper plate, and photo d shows the melting process of the coated copper plate. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] This embodiment provides a method for preparing a PVDF@basalt@TiO2 double-layer superhydrophobic coating, including the following steps:

[0035] (1) Preparation of hydrophobic nano-TiO2: 10g nano-TiO2 and 0.5g titanate coupling agent GR-330 were added to 100mL ethanol, 10mL water was added, the mixture was heated to 75℃ and stirred for 2h to obtain hydrophobic nano-TiO2.

[0036] (2) Preparation of hydrophobic basalt powder: 2g of octadecyltrimethoxysilane and 1g of silane coupling agent A171 were added to 150mL of ethanol, 15g of basalt powder was added, the mixture was heated to 40℃ and stirred for 2h to obtain hydrophobic basalt powder.

[0037] (3) Preparation of hydrophobic coating: 3g of hydrophobic nano TiO2, 2g of hydrophobic basalt powder and 5g of PVDF are mixed and added to 100mL of hexamethylphosphoric triamine solution. The mixture is stirred and mixed evenly to form a uniformly dispersed slurry, and the hydrophobic coating is obtained.

[0038] (4) Preparation of PVDF@basalt@TiO2 double-layer superhydrophobic coating: Anhydrous ethanol solution of epoxy resin was used as primer. First, the primer was sprayed on the surface of aluminum plate and cured at 15℃ for 3h. Then, the hydrophobic coating was sprayed on the primer surface and cured at 75℃ for 40min and 90℃ for 40min to obtain PVDF@basalt@TiO2 double-layer superhydrophobic coating.

[0039] The primer formulation is as follows: the mass ratio of epoxy resin, diethylenetriamine, and anhydrous ethanol is 1:0.05:1.8.

[0040] Example 2

[0041] This embodiment provides a method for preparing a PVDF@basalt@TiO2 double-layer superhydrophobic coating, including the following steps:

[0042] (1) Preparation of hydrophobic nano-TiO2: 10g nano-TiO2 and 1.5g titanate coupling agent OL-T951 were added to 100mL ethanol, 10mL water was added, the mixture was heated to 85℃ and stirred for 4h to obtain hydrophobic nano-TiO2.

[0043] (2) Preparation of hydrophobic basalt powder: 3g dodecyltrimethoxysilane and 2g silane coupling agent A151 were added to 150mL ethanol, 20g basalt powder was added, heated to 60℃, and stirred for 4h to obtain hydrophobic basalt powder.

[0044] (3) Preparation of hydrophobic coating: 5g of hydrophobic nano TiO2, 4g of hydrophobic basalt powder and 9g of PVDF are mixed and added to 100mL of hexamethylphosphoric triamine solution. The mixture is stirred and mixed evenly to form a uniformly dispersed slurry, and the hydrophobic coating is obtained.

[0045] (4) Preparation of PVDF@basalt@TiO2 double-layer superhydrophobic coating: Anhydrous ethanol solution of epoxy resin was used as primer. First, the primer was sprayed on the surface of aluminum plate and cured at 25°C for 1 hour. Then, the hydrophobic coating was sprayed on the primer surface and cured at 85°C for 20 minutes. Finally, it was cured at 100°C for 20 minutes to obtain PVDF@basalt@TiO2 double-layer superhydrophobic coating.

[0046] The primer formulation is as follows: the mass ratio of epoxy resin, diethylenetriamine, and anhydrous ethanol is 1:0.1:-2.2.

[0047] Example 3

[0048] This embodiment provides a method for preparing a PVDF@basalt@TiO2 double-layer superhydrophobic coating, including the following steps:

[0049] (1) Preparation of hydrophobic nano-TiO2: 10g nano-TiO2 and 1g titanate coupling agent TC-1 were added to 100mL ethanol, 10mL water was added, the mixture was heated to 80℃ and stirred for 3h to obtain hydrophobic nano-TiO2.

[0050] (2) Preparation of hydrophobic basalt powder: 2.5g of octadecyltrichlorosilane and 1.5g of silane coupling agent KH570 were added to 150mL of ethanol, 17g of basalt powder was added, the mixture was heated to 50℃ and stirred for 3h to obtain hydrophobic basalt powder.

[0051] (3) Preparation of hydrophobic coating: 4g of hydrophobic nano TiO2, 3g of hydrophobic basalt powder and 7g of PVDF are mixed and added to 100mL of hexamethylphosphoric triamine solution. The mixture is stirred and mixed evenly to form a uniformly dispersed slurry, and the hydrophobic coating is obtained.

[0052] (4) Preparation of PVDF@basalt@TiO2 double-layer superhydrophobic coating: Anhydrous ethanol solution of epoxy resin was used as primer. First, the primer was sprayed on the surface of aluminum plate and cured at 20℃ for 2h. Then, the hydrophobic coating was sprayed on the primer surface and cured at 80℃ for 30min. Finally, it was cured at 95℃ for 30min to obtain PVDF@basalt@TiO2 double-layer superhydrophobic coating.

[0053] The primer is formulated as follows: epoxy resin, diethylenetriamine and anhydrous ethanol in a mass ratio of 1:0.1:2.

[0054] The coating prepared in Example 3 was tested, and the results are shown in the figure. Figures 1-6 The coating has a contact angle of 155° and a hardness rating of 3H.

[0055] The results of the comparison of contact angle changes before and after 144 hours of acid, alkali and salt soaking are shown in Table 1.

[0056] Table 1

[0057]

[0058] As can be seen from the table above, the coating obtained by the present invention has excellent corrosion resistance.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a PVDF@basalt@TiO2 bilayer superhydrophobic coating, comprising the following steps: (1) Preparation of hydrophobic nano-TiO2: Nano-TiO2 and titanate coupling agent were added to a mixture of ethanol and deionized water, and the mixture was heated and stirred to prepare hydrophobic nano-TiO2. (2) Preparation of hydrophobic basalt powder: Long-chain alkyl silane and silane coupling agent with double bond are added to a mixture of ethanol and deionized water, and the mixture is heated and stirred to obtain hydrophobic basalt powder. (3) Preparation of hydrophobic coating: Hydrophobic nano-TiO2, hydrophobic basalt powder and PVDF are mixed and added to hexamethylphosphoric triamine solution, stirred and mixed evenly to form a uniformly dispersed slurry, and the hydrophobic coating is obtained. (4) Preparation of PVDF@basalt@TiO2 double-layer superhydrophobic coating: Anhydrous ethanol solution of epoxy resin is used as primer. First, the primer is sprayed on the surface of aluminum plate and cured. Then, the hydrophobic coating is sprayed on the primer surface and cured to obtain fluorocarbon resin superhydrophobic coating.

2. The preparation method according to claim 1, characterized in that, In step (1), the mass ratio of nano-TiO2 to titanate coupling agent is 10:0.5-1.5, and the heating and stirring reaction temperature is 75-85℃ for 2-4 hours.

3. The preparation method according to claim 2, characterized in that, The titanate coupling agent mentioned in step (1) is selected from at least one of TC-1, OL-T951, and GR-330.

4. The preparation method according to claim 1, characterized in that, In step (2), the mass ratio of the long-chain alkylsilane, the silane coupling agent with double bonds, and the basalt powder is 2-3:1-2:15-20, and the heating and stirring reaction temperature is 40-60℃, and the time is 2-4h.

5. The preparation method according to claim 4, characterized in that, The long-chain alkylsilane mentioned in step (2) is selected from at least one of octyltriethoxysilane, dodecyltrimethoxysilane, octadecyltrichlorosilane, and octadecyltrimethoxysilane.

6. The preparation method according to claim 4, characterized in that, The silane coupling agent with double bonds mentioned in step (2) is selected from at least one of KH570, A151, and A171.

7. The preparation method according to claim 1, characterized in that, The mass ratio of hydrophobic nano-TiO2, hydrophobic basalt powder and PVDF in step (3) is 3-5:2-4:5-9.

8. The preparation method according to claim 1, characterized in that, The primer formulation in step (4) is: epoxy resin, diethylenetriamine and anhydrous ethanol in a mass ratio of 1:0.05-0.1:1.8-2.

2. The primer is cured at a temperature of 15-25℃ for 1-3 hours.

9. The preparation method according to claim 1, characterized in that, The curing conditions for the topcoat in step (4) are: curing at 75-85℃ for 20-40 minutes and curing at 90-100℃ for 20-40 minutes.

10. A PVDF@basalt@TiO2 double-layer superhydrophobic coating prepared by the preparation method according to any one of claims 1-9.

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