A self-healing coating and a method for making the same

Abstract

The application discloses a kind of self-repairing coating and preparation method thereof, comprising the following steps: S1, selecting polylactic acid as base material;S2, dissolving and dispensing polylactic acid solution: polylactic acid powder is dissolved in solvent;S3, functionalized reinforcing material is added in polylactic acid solution;S4, the product in S3 is fluorinated surface treatment agent and silanization modification technology, then ultrasonic dispersion technology is used, to ensure that functional nanoparticles are uniformly distributed in solution;S5, new crosslinking agent is added, and the amount of use is 5% of total volume, to promote the crosslinking reaction between polylactic acid chain.S6, adopt double drying process, combine freeze drying and supercritical carbon dioxide drying technology.The coating in the application has efficient self-repairing function, excellent environmental adaptability and lower cost.The coating can quickly repair itself after being damaged, restore the original protective performance, and the repair process does not need external intervention, and the repair effect is durable and stable.

Description

Technical Field

[0001] This invention relates to the field of polymer coating technology, and in particular to a self-healing coating and its preparation method. Background Technology

[0002] With the ever-increasing demands on material performance in modern industry and daily life, coating materials are playing an increasingly important role in various fields, especially in the protection, decoration, and functional enhancement of substrates such as metals, concrete, and plastics. Coatings not only enhance the corrosion resistance, wear resistance, and oxidation resistance of materials but also improve their aesthetics. However, over time, coating materials are inevitably affected by external environmental factors, physical or chemical actions, leading to problems such as coating peeling, scratches, and cracks. This causes the material surface to lose its protective function, increases maintenance costs, and affects its long-term performance. Therefore, developing a self-healing coating material has become an important research direction in the field of materials science. A self-healing coating can not only automatically repair itself when damaged, restoring its original performance, but also effectively extend the service life of materials and reduce maintenance costs.

[0003] Currently, traditional coating materials such as metal coatings and polymer coatings, while providing some protection, are often damaged during use due to external environmental or physical and chemical effects. For example, coatings are prone to cracking and peeling under impact, friction, or chemical corrosion. When the coating is damaged, the substrate is exposed to the external environment, leading to corrosion and oxidation. Existing repair methods typically rely on manual intervention, such as manual application, spraying, or heating. Although these methods can temporarily restore the coating's protective function, the repair effect is usually not as good as the original coating, and the repair process is cumbersome and costly. Especially when the coating damage is large or deep, traditional repair methods are often ineffective and fail to restore the original performance of the coating. Therefore, improving the durability and self-healing ability of coatings and reducing manual intervention has become an important research direction in coating technology.

[0004] Self-healing coating technology has received widespread attention in recent years and has become a cutting-edge field in materials science. A self-healing coating refers to a coating that can automatically identify and repair damaged areas when subjected to external damage, restoring its original function. Advances in self-healing coating research have provided new ideas for overcoming the limitations of traditional coatings. Existing self-healing coating technologies mainly include microcapsule repair technology, reversible chemical repair technology, and self-healing polymer repair technology. Microcapsule repair technology involves adding microcapsules to the coating; when the coating is damaged, the microcapsules rupture, releasing the encapsulated repair agent to fill the damaged area. Reversible chemical repair technology introduces molecules with reversible chemical reactions, enabling the coating to undergo a self-repair reaction when damaged. Self-healing polymer technology designs polymers with self-healing functions, allowing them to recover their original state through chemical reactions or deformation when subjected to external forces. While these technologies have solved the problem of coating damage repair to some extent, some shortcomings remain, mainly manifested in unstable repair effects, slow repair speed, easy leakage of repair materials, and poor environmental adaptability. Especially in complex environments such as high temperature, low temperature, high humidity, or chemical corrosion, existing self-healing coatings often fail to achieve ideal repair results.

[0005] Therefore, designing a self-healing coating that is efficient, stable, and suitable for various environmental conditions has become a key research issue. Summary of the Invention

[0006] The purpose of this invention is to provide a self-healing coating and its preparation method, which has efficient self-healing function, excellent environmental adaptability, and low cost. This coating can quickly repair itself after being damaged, restoring its original protective properties, and the repair process requires no external intervention, with long-lasting and stable repair effects.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A method for preparing a self-healing coating includes the following steps: S1. Polylactic acid was selected as the base material; S2. Dissolving and preparing polylactic acid solution: Dissolve polylactic acid powder in a solvent; S3. Functionalized reinforcing materials were added to the polylactic acid solution; S4. The product in S3 is subjected to fluorination surface treatment agent and silanization modification technology, and then ultrasonic-assisted dispersion technology is used to ensure that the functional nanoparticles are uniformly distributed in the solution. S5. Add a novel crosslinking agent, using 5% of the total volume, to promote the crosslinking reaction between polylactic acid chains; S6 employs a dual drying process, combining freeze-drying and supercritical carbon dioxide drying technology.

[0008] More preferably, in step S2, 1.5g of polylactic acid powder is dissolved in a solvent, the solvent including dichloromethane or chloroform.

[0009] More preferably, in step S2, a combination of magnetic stirring and heating is used to stir the solution until it becomes completely transparent within a temperature range of 60°C to 70°C, and the concentration of the solution is precisely controlled between 1.5 and 3.0 g / ml.

[0010] More preferably, in S3, the functionalized reinforcing material comprises 1g of silica nanoparticles and 5ml of graphene oxide.

[0011] More preferably, in step S5, the novel crosslinking agent comprises 1,6-diisocyanate and triaminopropyltriethoxysilane, the temperature of the crosslinking reaction is set between 50°C and 70°C, and the amount of crosslinking agent added and the reaction rate are precisely controlled by spin coating and electrospinning technology to ensure the uniformity and optimal effect of crosslinking.

[0012] More preferably, in step S6, the prepared aerogel coating sample is placed in a freeze-drying device and freeze-dried at a low temperature of -40°C to -80°C to remove moisture by sublimation, maintaining high porosity and low density. Then, supercritical CO2 drying technology is used to further remove residual solvent and moisture, ensuring the ultra-low density and high thermal insulation performance of the aerogel.

[0013] A self-healing coating is prepared according to the above-described method for preparing a self-healing coating.

[0014] In summary, the present invention has the following beneficial effects: Firstly, the coating in this invention possesses highly efficient self-healing capabilities, excellent environmental adaptability, and low cost. This coating can rapidly repair itself after damage, restoring its original protective properties, and the repair process requires no external intervention, resulting in a long-lasting and stable repair effect. Through innovative design, the coating of this invention not only has good durability and self-healing ability but also uses environmentally friendly materials, meeting the requirements of green and sustainable development, and has broad application prospects.

[0015] Secondly, by combining supercritical drying technology with temperature control optimization, this invention ensures that the aerogel maintains its high specific surface area and low density while possessing higher stability and strength.

[0016] Thirdly, the coating of this invention further enhances the performance of aerogel through innovative surface functionalization technology and nanomaterial reinforcement, especially in terms of anti-pollution, UV resistance and thermal stability.

[0017] Fourth, this invention enhances the antibacterial properties, thermal stability, and mechanical strength of aerogel by introducing functional nanomaterials, such as titanium dioxide nanoparticles and carbon nanotubes. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the effect of the coating in this invention; Detailed Implementation The present invention will be further described in detail below with reference to the accompanying drawings.

[0019] An example of a method for preparing a self-healing coating includes the following steps: S1. Polylactic acid (PLA) was chosen as the base material. PLA is a bio-based material with good biodegradability and environmental friendliness, making it suitable for the preparation of green coatings.

[0020] S2. Dissolving and Preparing the Polylactic Acid Solution: Dissolve 1.5g of polylactic acid powder in a solvent, such as dichloromethane or chloroform, to ensure complete dissolution of the polylactic acid. To obtain a homogeneous solution, use a combination of magnetic stirring and heating at a temperature range of 60°C to 70°C until the solution becomes completely transparent. The concentration of the solution is precisely controlled between 1.5 and 3.0 g / ml to ensure its suitability for subsequent cross-linking reactions and aerogel formation. This process ensures the homogeneity of the polylactic acid in the solution and provides a stable foundation for subsequent steps.

[0021] S3. Functionalized reinforcing materials, including 1g of silica nanoparticles and 5ml of graphene oxide, were added to the polylactic acid solution to further improve the mechanical strength, thermal stability, and protective function of the aerogel.

[0022] S4. The product from S3 is subjected to fluorination surface treatment agent and silanization modification technology, followed by ultrasonic-assisted dispersion technology to ensure uniform distribution of functional nanoparticles in the solution. This improves the aerogel's water resistance, antifouling properties, and adhesion to the substrate.

[0023] S5. A novel crosslinking agent is added at 5% of the total volume to promote the crosslinking reaction between polylactic acid chains. The novel crosslinking agent comprises 1,6-diisocyanate and triaminopropyltriethoxysilane. The crosslinking reaction temperature is set between 50°C and 70°C, and the amount of crosslinking agent added and the reaction rate are precisely controlled using spin coating and electrospinning techniques to ensure uniform crosslinking and optimal results. This further enhances the mechanical strength and thermal stability of the aerogel.

[0024] S6 employs a dual drying process, combining freeze-drying and supercritical carbon dioxide drying. The prepared aerogel coating sample is placed in a freeze-drying device and freeze-dried at a low temperature of -40℃ to -80℃. Sublimation removes moisture, maintaining high porosity and low density. Then, supercritical CO2 drying further removes residual solvent and moisture, ensuring the aerogel's ultra-low density and high thermal insulation performance. This method is used to obtain aerogels with ultra-high specific surface area and low density. This dual drying technique not only effectively removes solvents but also ensures that the microporous structure of the aerogel is preserved to the greatest extent, improving its overall performance.

[0025] Specifically, this invention uses polylactic acid (PLA) as the base material to prepare aerogels. PLA is an environmentally friendly material with good biodegradability. As a polymer, it possesses high thermal stability and excellent mechanical properties. Through the preparation process designed in this invention, PLA can effectively form an aerogel structure at high temperatures, while maintaining low density and high specific surface area, providing excellent thermal insulation and compressive strength. This technology, through precise control of PLA solubility, cross-linking reaction, and subsequent drying processes, results in aerogel materials with good stability and mechanical properties, making them particularly suitable for the development of high-performance thermal insulation and protective materials.

[0026] This invention combines supercritical drying technology with optimized temperature control to ensure that the aerogel maintains its high specific surface area and low density while possessing higher stability and strength. Traditional drying methods often result in incomplete removal of moisture from the aerogel, affecting its pore structure and performance. This invention, however, utilizes supercritical CO2 drying technology, which can completely remove the solvent without damaging the aerogel's pore structure, resulting in a more uniform and high-quality aerogel. Combined with optimized temperature control, temperature and pressure changes during the drying process can be precisely controlled, preventing shrinkage or deformation of the aerogel and ensuring that the final product possesses stable physical properties and excellent thermal insulation and mechanical properties. Furthermore, innovative surface functionalization technology and nanomaterial reinforcement further enhance the aerogel's performance, particularly in terms of anti-fouling, UV resistance, and thermal stability. To improve the aerogel material's water resistance, anti-fouling properties, and adhesion to substrates, this invention employs fluorination surface treatment and silanization modification technology. These surface modification methods effectively enhance the hydrophobicity of the aerogel surface, preventing moisture penetration and contaminant accumulation, thereby maintaining its efficient thermal insulation function and significantly extending its service life in various environments.

[0027] Furthermore, this invention enhances the antibacterial properties, thermal stability, and mechanical strength of aerogels by introducing functional nanomaterials, such as titanium dioxide nanoparticles and carbon nanotubes. Titanium dioxide, a material with strong antibacterial properties, effectively improves the antimicrobial ability of aerogels, while carbon nanotubes help improve the thermal conductivity and structural strength of aerogels. Through the addition of these reinforcing materials, aerogels not only possess better physical properties but also exhibit superior performance in harsh environments, making them suitable for various fields such as construction, energy, and environmental protection.

[0028] In summary, this invention addresses the shortcomings of traditional aerogel materials in terms of environmental friendliness and high strength. Furthermore, through innovative surface modification and nanomaterial reinforcement, it achieves multifunctionality and high efficiency. The technology of this invention greatly expands the application prospects of aerogel materials, particularly in high-temperature insulation, anti-pollution protection, and long-term use, demonstrating significant advantages.

[0029] It should also be noted that, such as Figure 1 As shown, the self-healing properties of the coating are demonstrated. First, a complete aerogel coating was cut in half with scissors. After cutting, the coating was brought into contact with air at room temperature. After 15 minutes, the cut pieces of aerogel coating re-bonded together, indicating the coating's excellent self-healing properties.

[0030] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a self-healing coating, characterized in that, Includes the following steps: S1. Polylactic acid was selected as the base material; S2. Dissolving and preparing polylactic acid solution: Dissolve 1.5g of polylactic acid powder in a solvent, and use a combination of magnetic stirring and heating to stir the solution until it is completely transparent within a temperature range of 60℃ to 70℃. The concentration of the solution is precisely controlled between 1.5 and 3.0g / ml. The solvent includes dichloromethane or chloroform. S3. A functionalized reinforcing material was added to the polylactic acid solution, the functionalized reinforcing material comprising 1g of silica nanoparticles and 5ml of graphene oxide. S4. The product in S3 is subjected to fluorination surface treatment and silanization modification, and then ultrasonic-assisted dispersion technology is used to ensure that the functional nanoparticles are uniformly distributed in the solution. S5. Add a crosslinking agent at a dosage of 5% of the total volume to promote the crosslinking reaction between polylactic acid chains. The crosslinking agent includes 1,6-diisocyanate and triaminopropyltriethoxysilane. The temperature of the crosslinking reaction is set between 50°C and 70°C. The amount of crosslinking agent added and the reaction rate are precisely controlled by spin coating and electrospinning technology to ensure the uniformity and optimal effect of crosslinking. S6 employs a dual drying process, combining freeze-drying and supercritical carbon dioxide drying technology. The product of S5 is placed in a freeze-drying device and freeze-dried at a low temperature of -40℃ to -80℃. Sublimation is used to remove moisture, maintaining high porosity and low density. Then, supercritical CO2 drying technology is used to further remove residual solvents and moisture, ensuring the final product has ultra-low density and high thermal insulation performance.

2. A self-healing coating, characterized in that, The self-healing coating is prepared according to the method described in claim 1.

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