CN115181482A - A kind of self-healing epoxy resin-based superhydrophobic coating and preparation method thereof - Google Patents

Abstract

The invention discloses a self-healing epoxy resin-based super-hydrophobic coating and a preparation method thereof, belonging to the technical field of self-repairing and super-hydrophobic coating preparation. The invention solves the problems of poor mechanical stability, short service life, complicated preparation process and the like existing in the existing hydrophobic coating preparation method. In the present invention, epoxy resin with shape memory property is used as a binder, and a hydrophobically modified _SiO2 inorganic filler is combined to prepare a coating by a spraying method. The static contact angle with water is greater than 150° and the rolling angle is less than 5°, It has excellent superhydrophobicity, and the coating loses its hydrophobicity after being damaged by external mechanical force, and the surface microstructure can be restored by heating, thereby restoring its superhydrophobicity.

Description

A kind of self-healing epoxy resin-based superhydrophobic coating and preparation method thereof

technical field

The invention relates to a self-healing epoxy resin-based super-hydrophobic coating and a preparation method thereof, belonging to the technical field of self-healing and super-hydrophobic coating preparation.

Background technique

Superhydrophobicity is very widespread in nature. Many plants, animals, and insects have superhydrophobic surfaces. Superhydrophobic surfaces generally refer to surfaces with a contact angle greater than 150° and a rolling angle less than 10°. The surface structure and the lower surface energy are jointly determined by these two factors. Superhydrophobic surfaces have many unique surface properties, such as self-cleaning, antifouling, anti-icing and anti-fog properties, which make them have great application prospects in the fields of life and production. However, in the natural environment, the superhydrophobic surface is easily damaged: on the one hand, due to chemical damage such as ultraviolet light or acid rain to the destruction of low surface energy substances on the superhydrophobic surface, on the other hand, due to physical damage such as wind and sand abrasion damage to the superhydrophobic surface Microstructure of hydrophobic surfaces. Plants or animals with superhydrophobic properties can repair damaged superhydrophobic surfaces by secreting waxes or oils. However, for artificial superhydrophobic surfaces, in order to restore the damaged superhydrophobicity, the surface must be repaired or even replaced with the superhydrophobic coating, resulting in additional expenditure and labor. Therefore, the self-healing function ubiquitous in nature is introduced into the superhydrophobic coating, and the shape memory epoxy resin is used as the matrix to prepare the superhydrophobic coating. Once the surface of the coating is damaged by external mechanical force, the microstructure is destroyed and the superhydrophobicity is lost. , the damaged superhydrophobic surface is repaired by heating the shape memory effect of epoxy resin, thereby prolonging the service life of the superhydrophobic surface.

SUMMARY OF THE INVENTION

In order to solve the problems of poor mechanical stability, cumbersome preparation process, short service life and the like existing in the existing hydrophobic coating preparation methods, the present invention provides a self-healing epoxy resin-based superhydrophobic coating and a preparation method thereof.

Technical scheme of the present invention:

A self-healing epoxy resin-based superhydrophobic coating, the coating comprises microstructured inorganic particles and a film-forming substance, the inorganic particles are hydrophobically modified SiO ₂ , and the film-forming substance is an epoxy resin with shape memory properties, The coating has superhydrophobic self-healing function.

The preparation method of the above-mentioned self-healing epoxy resin-based super-hydrophobic coating is to coat the spraying liquid on the substrate by spraying.

Further limited, the spraying liquid is prepared from the following raw materials by weight: 10-20 g epoxy resin, 10-20 g SiO ₂ , 100-200 μL fluorosilane, 20-40 mL acetone and 2.4-4.8 g curing agent.

To further define, the mass ratio of epoxy resin to SiO ₂ is 1:1.

Further limited, the particle size of SiO ₂ is 10 μm.

Further limited, the fluorosilane is perfluorodecyltriethoxysilane.

Further limited, the epoxy resin is E51 epoxy resin.

Further limited, the curing agent is a mixture of polyetheramine and m-xylylenediamine.

More specifically, the mass ratio of polyetheramine and m-xylylenediamine is 2:1.

The operation process of the above method is as follows:

(1) Substrate pretreatment:

The substrate was cleaned with ethanol, then sonicated in acetone for 20 min, and finally rinsed with deionized water and dried;

(2) Preparation of spray liquid:

First, add SiO to acetone, then add fluorosilane, stir magnetically at 600 rpm/min for ₂₀ min to obtain a hydrophobically modified SiO white solution, then add epoxy resin, stir at room temperature for ₁₅ min at 400 r/min , and finally add the curing agent and stir for 15min to obtain a spray liquid;

(3) Spraying treatment:

The spraying liquid is sprayed on the surface of the substrate by the spraying method, and the coating is obtained after heating and curing;

The surface morphology and microstructure of the coating were deformed after being extruded by a tablet press, and the superhydrophobicity was lost. After heat treatment, the surface morphology and microstructure were restored, and the superhydrophobicity was restored.

In the present invention, epoxy resin with shape memory property is used as film-forming material, _SiO2 inorganic filler is mixed, and coating is prepared by spraying method. 5°, with excellent self-cleaning properties. And after being damaged by external mechanical force, the surface microstructure can be restored by heating, thereby restoring its superhydrophobic properties. Compared with the prior art, it also has the following beneficial effects:

(1) The present invention adopts a one-step spray method to prepare a self-healing superhydrophobic coating, which has the advantages of simple process, mild conditions, low energy consumption, etc., and is easy to realize large-scale production, and the prepared coating has a certain strength, good mechanical stability, and It is firmly combined with the metal substrate and is not easy to fall off, which improves the shortcoming of poor durability of the existing superhydrophobic coating, greatly improves its durability in practical applications, and can be well used in the fields of self-cleaning and antifouling.

(2) After the coating obtained by the present invention is damaged and deformed by external mechanical force, the surface microstructure can be recovered by heating and utilizing the shape memory property of epoxy resin, thereby recovering its superhydrophobic performance and having a superhydrophobic self-repairing function .

Description of drawings

Fig. 1 is the scanning electron microscope image of the superhydrophobic coating surface prepared by embodiment 1;

Fig. 2 is the surface water contact angle of the superhydrophobic coating prepared in Example 1;

Fig. 3 is the infrared spectrogram analysis of the superhydrophobic coating prepared by each embodiment;

Fig. 4 is a digital photograph of the heating recovery process of the superhydrophobic coating prepared in Example 1 after being damaged by external force;

5 is an in-situ 3D profile scanning diagram of the heating recovery process of the surface of the superhydrophobic coating prepared in Example 1 after being damaged by external force;

6 is a graph showing the change of water contact angle of the surface of the superhydrophobic coating prepared in Example 1 during the heating recovery process after being damaged by external force.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The experimental methods used in the following examples are conventional methods unless otherwise specified. The used materials, reagents, methods and instruments, unless otherwise specified, are conventional materials, reagents, methods and instruments in the art, which can be obtained by those skilled in the art through commercial channels.

Example 1:

The mass ratio of epoxy resin and silica in the present embodiment is 1:1, and the specific process of preparing the superhydrophobic coating in the present embodiment is as follows:

( ₁ ) Add 10 g of SiO with a particle size of 10 μm to 20 mL of acetone, then add 100 μL of perfluorodecyltriethoxysilane, and magnetically stir at 600 rpm/min for ₂₀ min to obtain a hydrophobically modified SiO white solution.

(2) 10g of E-51 epoxy resin was added to the above hydrophobically modified _SiO2 white solution, stirred at 400r/min for 15min at room temperature, and then 1.6g of polyetheramine and 0.8g of isophthalic acid were added. methylamine curing agent, and continue stirring for 15 min to obtain a pre-spraying solution.

(3) The metal aluminum was cut to make the surface size of the aluminum sheet 40mm*40mm, cleaned with ethanol, then ultrasonicated with acetone for 20min, and finally rinsed with deionized water, and dried for use.

(4) The pre-spraying solution is sprayed on the aluminum sheet by the spraying method, wherein the spraying air pressure is controlled to 0.3MPa, and the spraying distance is 15cm, and then the aluminum sheet is heated and cured in an oven to obtain a self-healing superhydrophobic coating, and the heating and curing process is 60 ℃ curing for 1h, 100 ℃ curing for 2h, the coating thickness is 100μm.

The structure and properties of the coatings obtained in this example were characterized:

(1) The microstructure of the coating obtained in this example is characterized. The scanning electron microscope image is shown in Figure 1. It can be seen from Figure 1 that the surface of the coating has a graded rough structure.

(2) The water contact angle test was performed on the coating obtained in Example 1. The results are shown in Figure 2. As can be seen from the figure, the water contact angle WCA is 153°, and the coating has super-hydrophobic properties.

(3) The infrared spectrum curve of the coating obtained in Example 1 is shown in Figure 3, and it can be seen from Figure 3 that the low surface energy fluorosilane was successfully introduced into the superhydrophobic coating.

(4) The damage and recovery test of the surface microstructure was carried out on the coating obtained in Example 1. Specifically, a tablet press (pressure 5-8MPa) was used to simulate the destructive force of the outside on the surface of the coating, and then heated and recovered, as shown in the figure As shown in 4-5, the superhydrophobic coating was extruded by a tablet press, and it was found that the surface and microstructure of the superhydrophobic coating were deformed, and the superhydrophobicity was lost. Recoverable, that is, the coating prepared in this example has excellent microstructure self-healing function.

(5) Test the surface water contact angle of the coating obtained in this example during the damage and recovery test of the surface microstructure. The results are shown in Figure 6. It can be seen from Figure 6 that the superhydrophobicity of the coating can also be Get a good recovery.

Comparative Example 1:

The mass ratio of epoxy resin and silica in this comparative example is 4:1. The specific process of preparing the superhydrophobic coating in this comparative example is as follows:

( ₁ ) Add 2.5 g of SiO with a particle size of 10 μm to 20 mL of acetone, then add 100 μL of perfluorodecyltriethoxysilane, and magnetically stir at 600 rpm/min for ₂₀ min to obtain a hydrophobically modified SiO white solution .

(2) 10g of E-51 epoxy resin was added to the above hydrophobically modified _SiO2 white solution, stirred at 400r/min for 15min at room temperature, and then 1.6g of polyetheramine and 0.8g of isophthalic acid were added. methylamine curing agent, and continue stirring for 15 min to obtain a pre-spraying solution.

(3) The metal aluminum was cut to make the surface size of the aluminum sheet 40mm*40mm, cleaned with ethanol, then ultrasonicated with acetone for 20min, and finally rinsed with deionized water, and dried for use.

(4) The pre-spraying solution is sprayed on the aluminum sheet by the spraying method, wherein the spraying air pressure is controlled to 0.3MPa, and the spraying distance is 15cm, and then the aluminum sheet is heated and cured in an oven to obtain a self-healing superhydrophobic coating, and the heating and curing process is 60 ℃ curing for 1h, 100 ℃ curing for 2h, the coating thickness is 100μm.

The superhydrophobic properties of the coatings obtained in this example were characterized:

(1) The water contact angle test of the coating obtained in this comparative example shows that the water contact angle WCA is 137°, that is, the coating does not have super-hydrophobic properties, which is mainly due to the fact that when the amount of added is too little, the hydrophobicized The _SiO2 particles are mostly immersed in the network structure composed of epoxy resin, thus resulting in a microstructure of the coating without superhydrophobic properties.

Comparative Example 2:

The mass ratio of epoxy resin and silica in this comparative example is 1:2. The specific process of preparing the superhydrophobic coating in this comparative example is as follows:

(1) 20 g of SiO with a particle size of ₁₀ μm was added to 20 mL of acetone, then 100 μL of perfluorodecyltriethoxysilane was added, and magnetically stirred at 600 rpm/min for ₂₀ min to obtain a hydrophobically modified SiO white solution.

(2) 10g of E-51 epoxy resin was added to the above hydrophobically modified _SiO2 white solution, stirred at 400r/min for 15min at room temperature, and then 1.6g of polyetheramine and 0.8g of isophthalic acid were added. methylamine curing agent, and continue stirring for 15 min to obtain a pre-spraying solution.

(3) The metal aluminum was cut to make the surface size of the aluminum sheet 40mm*40mm, cleaned with ethanol, then ultrasonicated with acetone for 20min, and finally rinsed with deionized water, and dried for use.

(4) The pre-spraying solution is sprayed on the aluminum sheet by the spraying method, wherein the spraying air pressure is controlled to 0.3MPa, and the spraying distance is 15cm, and then the aluminum sheet is heated and cured in an oven to obtain a self-healing superhydrophobic coating, and the heating and curing process is 60 ℃ curing for 1h, 100 ℃ curing for 2h, the coating thickness is 100μm.

(1) The water contact angle test of the coating obtained in this comparative example shows that the water contact angle WCA is 155°, that is, the coating has super-hydrophobic properties.

(2) The damage and recovery test of the surface microstructure was carried out on the coating obtained in this comparative example. Specifically, a tablet press (pressure 5-8 MPa) was used to simulate the destructive force on the surface of the coating from the outside world, and then heated and recovered. The results are as follows Description: The super-hydrophobic coating was extruded by a tablet press, and it was found that the surface and microstructure of the super-hydrophobic coating became broken after compression, the super-hydrophobic performance was lost, and it did not have the self _- healing function of the microstructure, which was mainly due to the If it is added too much, the network structure composed of epoxy resin cannot wrap the inorganic filler with hydrophobicity, and the mechanical stability of the microstructure is poor.

The above are only preferred embodiments of the present invention. In view of the fact that those skilled in the art to which the present invention pertains can make appropriate changes and modifications to the above-mentioned embodiments, the present invention is not limited to the above-mentioned specific embodiments. Some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention.

Claims (9)

1. a self-repairing epoxy resin-based super-hydrophobic coating, is characterized in that, this coating comprises microstructure inorganic particle and film-forming material, and inorganic particle is hydrophobically modified SiO ₂ , and film-forming material is epoxy resin , the coating has superhydrophobic self-healing function. 2. a spraying liquid preparing the self-repairing epoxy resin-based super-hydrophobic coating of claim 1, is characterized in that, spraying liquid is prepared from the raw material of following parts by weight: 10～20g epoxy resin, 10g～ 20 g SiO ₂ , 100-200 μL fluorosilane, 20 mL-40 mL acetone, and 2.4 g-4.8 g curing agent. 3. the spray liquid of preparing self-repairing epoxy resin-based super-hydrophobic coating according to claim 2, is characterized in that, the mass ratio of epoxy resin and SiO ₂ is 1:1, and the particle size of SiO ₂ is 10 μm . 4. The spray liquid for preparing self-healing epoxy resin-based superhydrophobic coating according to claim 2, wherein the fluorosilane is perfluorodecyltriethoxysilane. 5. The spray liquid for preparing self-healing epoxy resin-based superhydrophobic coating according to claim 2, wherein the epoxy resin is E51 epoxy resin. 6. The spray liquid for preparing self-repairing epoxy resin-based superhydrophobic coating according to claim 2, wherein the curing agent is a mixture of polyetheramine and m-xylylenediamine. 7. The spray solution of preparing self-repairing epoxy resin-based superhydrophobic coating according to claim 6, wherein the mass ratio of polyetheramine and m-xylylenediamine is 2:1. 8. the method for preparing the self-repairing epoxy resin-based superhydrophobic coating using the spraying liquid according to claim 2, is characterized in that, the method is that the spraying liquid is applied on the substrate by means of spraying. 9. the preparation method of self-healing epoxy resin-based super-hydrophobic coating according to claim 8, is characterized in that, this method operating process is: (1) Substrate pretreatment: The substrate was cleaned with ethanol, then sonicated in acetone for 20 min, and finally rinsed with deionized water and dried; (2) Preparation of spray liquid: First, add SiO to acetone, then add fluorosilane, stir magnetically at 600 rpm/min for ₂₀ min to obtain a hydrophobically modified SiO white solution, then add epoxy resin, stir at room temperature for ₁₅ min at 400 r/min , and finally add the curing agent and stir for 15min to obtain a spray liquid; (3) Spraying treatment: The spraying liquid is sprayed on the surface of the substrate by the spraying method, and the coating is obtained after heating and curing; The surface morphology and microstructure of the coating were deformed after being extruded by a tablet press, and the superhydrophobicity was lost. After heat treatment, the surface morphology and microstructure were restored, and the superhydrophobicity was restored.

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