A CeO2 polyurethane composition with ultraviolet shielding function and its preparation method
By generating a SiO2 passivation layer on the surface of nano-CeO2 and loading it onto GO sheets, the problem of strong oxidation catalysis of nano-cerium dioxide was solved, and a coating composition with high efficiency of ultraviolet shielding performance and long life was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI HUAMING GAONA RARE EARTH NEW MATERIAL CO LTD
- Filing Date
- 2026-05-08
- Publication Date
- 2026-06-02
AI Technical Summary
Nano-cerium dioxide has strong oxidizing and catalytic properties, and the effect of adding antioxidants is poor, which affects the performance of the polymer matrix. How to effectively reduce its oxidizing properties and manufacture high-performance ultraviolet shielding composite materials is a key question.
A SiO2 passivation layer was generated in situ on the surface of nano-CeO2 using the sol-gel method, forming CeO2@SiO2 core-shell structured particles, which were then loaded onto GO sheets. The barrier effect of the GO sheets was used to suppress the migration of photogenerated carriers and reduce the oxidation catalytic performance.
It effectively inhibits the photocatalytic oxidation of CeO2, improves the mechanical properties and weather resistance of coating compositions, and extends service life.
Smart Images
Figure CN122127873A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of composite materials technology, specifically to a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method. Background Technology
[0002] In recent years, inorganic nano-UV shielding agents have gradually become core materials to replace organic absorbers due to their excellent UV shielding performance, high thermal stability, and chemical stability. Among them, nano-titanium dioxide (TiO2) and zinc oxide (ZnO) are the most widely used. However, these conventional inorganic fillers have obvious shortcomings: First, the UV shielding band is narrow, and the shielding effect on long-wave UVA is limited, making it difficult to achieve efficient protection across the entire wavelength range. Second, they have strong photocatalytic activity, which can generate a large number of photogenerated carriers under UV irradiation, catalyzing the oxidative degradation of the surrounding polymer substrate, leading to fabric embrittlement and coating cracking. Third, the high surface energy of nanoparticles makes them prone to agglomeration in aqueous polymer systems, forming local agglomeration points, further aggravating local degradation of the substrate, and affecting the fabric feel and coating uniformity. Nano-cerium oxide (CeO2), as a novel rare-earth-based inorganic UV shielding material, has advantages due to its unique fluorite crystal structure and CeO2 content. 3+ / Ce 4+ Its reversible redox properties exhibit broad-spectrum UV absorption performance far exceeding that of traditional TiO2 and ZnO, simultaneously covering the entire UVA and UVB bands, and possessing high visible light transmittance without causing whitening of fabrics or coatings, making it a promising candidate for UV shielding. However, its strong catalytic oxidation activity easily leads to oxidative degradation of the polymer matrix, limiting its application in polymer composites. To address the issue of excessively high catalytic oxidation activity of nano-CeO2, existing technologies employ in-situ encapsulation of CeO2 with silane coupling agents for passivation, physically isolating active sites. Chinese invention patent CN101857713B discloses a water-dispersible polyester composite material with UV shielding function and its application. This invention addresses the high oxidizing power and easy agglomeration of nano-cerium dioxide by modifying nano-cerium dioxide with a silane coupling agent and then adding a composite antioxidant, achieving excellent UV shielding performance.
[0003] However, nano-cerium dioxide has strong oxidizing and catalytic properties, and the effect of adding antioxidants is poor. Furthermore, the addition of antioxidants can easily affect the properties of the polymer matrix. Therefore, how to effectively reduce the oxidizing properties of nano-cerium dioxide and manufacture high-performance UV-shielding composite materials has become an urgent problem to be solved. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the primary objective of this application is to provide a CeO2 polyurethane composition with UV shielding function and its preparation method. This application utilizes a sol-gel method to grow a SiO2 passivation layer in situ on the surface of nano-CeO2, effectively isolating the catalytic degradation of the polyurethane matrix material by nano-CeO2 and extending the service life of the coating composition. Then, by loading CeO2@SiO2 core-shell structured particles onto GO (hydroxylated graphene oxide) sheets, the GO sheets act as a dispersion carrier, effectively dispersing the CeO2@SiO2 core-shell structured particles within the matrix. Furthermore, the sheet-like barrier effect of GO further inhibits the migration of photogenerated carriers from CeO2, weakening its oxidative catalytic performance. While ensuring excellent UV shielding performance of the coating, the strong catalytic oxidation of CeO2 is effectively suppressed, extending the coating's service life.
[0005] To achieve the above objectives, this application provides the following technical solution:
[0006] In a first aspect, this application provides a CeO2 polyurethane composition with ultraviolet shielding function, the composition comprising an ultraviolet shielding filler, an aqueous polyurethane emulsion and a crosslinking agent; the ultraviolet shielding filler is obtained by generating a SiO2 passivation layer in situ on the surface of nano-CeO2 to obtain CeO2@SiO2 core-shell structured particles, and then uniformly loading the CeO2@SiO2 core-shell structured particles onto the surface of GO sheets.
[0007] Preferably, the solid content of the aqueous polyurethane emulsion is 30-40%.
[0008] It should be noted that the CeO2 polyurethane composition prepared in this application can be applied to the UV protection treatment of fabrics. Using a polyurethane emulsion with a solid content of 30%-40% can ensure that the roll-up rate is stable at 70-75% during the treatment process, so that the coating will not be too thin due to being too thin, nor will the fabric be stiff due to being too thick.
[0009] Preferably, the crosslinking agent is any one of SAC-100, RP-1, Y-2016 and Y-301.
[0010] Secondly, this application provides a method for preparing a CeO2 polyurethane composition with ultraviolet shielding function, comprising the following steps:
[0011] S1, mix nano CeO2, anhydrous ethanol and deionized water, stir and sonicate, adjust the pH to 4-5, add diluted silane coupling agent dropwise, and react to obtain CeO2@SiO2 core-shell structured particles;
[0012] S2, CeO2@SiO2 core-shell structured particles were prepared into a dispersion, GO dispersion was added, stirred and sonicated, and reacted at a constant temperature to obtain the ultraviolet shielding filler;
[0013] S3, UV-shielding filler is added to polyurethane emulsion, stirred and impregnated, dispersed at high speed, ultrasonically treated, crosslinking agent is added, and stirred and mixed to obtain a CeO2 polyurethane composition with UV shielding function.
[0014] Preferably, the specific process of S1 is as follows: nano CeO2, anhydrous ethanol and deionized water are mixed and stirred at 300-400 rpm at room temperature for 15-20 min, followed by ultrasonication at 150-200W power for 20-30 min, adjusting the pH to 4-5, and then diluted silane coupling agent is added dropwise while maintaining a stirring rate of 350-400 rpm throughout the process, completing the addition within 30 min. Then, the reaction is carried out at 55-65℃ and a stirring rate of 550-650 rpm for 3.5-4.5 h. After centrifugation, washing and drying, CeO2@SiO2 core-shell structured particles are obtained; the particle size of the nano CeO2 is 50-80 nm.
[0015] It should be noted that at a constant temperature of 55-65℃, the hydrolysis and condensation reaction of KH-570 can be accelerated, promoting the condensation of silanol groups and CeO2 surface hydroxyl groups to form a dense and uniform SiO2 coating layer. During the stirring process, the system homogeneity can be ensured, avoiding the agglomeration of CeO2 particles, while promoting the full reaction. This ensures that KH-570 is completely hydrolyzed to form a complete SiO2 coating layer.
[0016] Preferably, the silane coupling agent diluted in S1 is obtained by diluting KH-570 in anhydrous ethanol at a mass ratio of (1-1.3):40.
[0017] It should be noted that diluting KH-570 with anhydrous ethanol can reduce its concentration and avoid excessively high local concentrations after addition, which could lead to rapid hydrolysis, aggregation of silanol groups, and the formation of an uneven coating layer. Adding KH-570 at a dropping rate of 1 drop / second can ensure that KH-570 is evenly dispersed in the system and comes into full contact with CeO2 particles, achieving uniform coating.
[0018] Preferably, the mass ratio of nano CeO2, anhydrous ethanol, deionized water and silane coupling agent is (4.5-5.5):(150-160):(45-55):(39-42).
[0019] Preferably, the specific process of S2 is as follows: CeO2@SiO2 core-shell structured particles, anhydrous ethanol, and deionized water are mixed and stirred at 400-500 rpm for 10-15 min to prepare a dispersion. GO dispersion is added, and the mixture is stirred at 350-400 rpm at room temperature for 20-25 min, followed by ultrasonication at 180-200W power for 50-60 min while maintaining stirring at 300 rpm. Then, the mixture is stirred at 500-550 rpm at 55-65℃ for 4-4.5 h. After centrifugation, washing, and drying, the UV-shielding filler is obtained. The GO dispersion is obtained by adding GO powder to deionized water and then ultrasonicating. The mass ratio of GO powder to deionized water is (1-3):1000. The hydroxyl content of the GO powder is 3-4 wt.%.
[0020] It should be noted that in this step, controlling the mass ratio of CeO2@SiO2 core-shell structured particles to GO to be 20:1 ensures that the GO sheets can be fully loaded with CeO2@SiO2 core-shell structured particles, avoiding insufficient or excessive GO addition that could lead to sheet stacking. During the addition of the GO dispersion, the addition rate needs to be controlled to avoid uneven GO dispersion caused by excessively rapid addition. After initial loading of the CeO2@SiO2 core-shell structured particles onto the GO sheets through stirring and sonication, the reaction continues at a constant temperature of 55-65℃. This promotes the formation and stabilization of hydrogen bonds between the CeO2@SiO2 core-shell structured particles and the GO sheets, enhancing the binding force and preventing the CeO2@SiO2 core-shell structured particles from detaching from the GO sheets.
[0021] Preferably, the mass ratio of CeO2@SiO2 core-shell structured particles, anhydrous ethanol, deionized water and GO dispersion in S2 is (4.5-5.5):78.9:50:(225-275).
[0022] Preferably, the specific process of S3 is as follows: the ultraviolet shielding filler is added to the polyurethane emulsion, stirred at 450-550 rpm at room temperature for 10-15 min, then dispersed at 5000-6000 rpm for 15-20 min, then ultrasonically treated at 180-200W power for 15-20 min, and allowed to stand for 72 h. If no precipitation occurs, a crosslinking agent is added, and the mixture is stirred at 200-300 rpm for 10-15 min. The viscosity of the emulsion is adjusted to 200-300 mPa·s at room temperature to obtain a CeO2 polyurethane composition with ultraviolet shielding function. The mass ratio of the ultraviolet shielding filler, polyurethane emulsion and crosslinking agent is (5-8):(90-95):(1-2).
[0023] The beneficial effects of this application are:
[0024] This application utilizes the hydrolysis reaction of a silane coupling agent to generate a SiO2 passivation film in situ on the surface of nano-CeO2, thereby neutralizing the CeO2 surface layer. 3+ / Ce 4+ The active sites are completely sealed, preventing photogenerated charge carriers from escaping from the CeO2 surface and avoiding contact with the polyurethane molecular chains, thereby inhibiting the photocatalytic oxidation performance of CeO2. Simultaneously, the SiO2 coating layer undergoes a condensation reaction with the hydroxyl groups on the CeO2 surface, forming stable Si-O-Ce chemical bonds. This not only improves the density and adhesion of the coating layer but also stabilizes oxygen vacancy defects on the CeO2 surface, reducing the generation of photogenerated charge carriers and further decreasing its oxidation catalytic activity. Furthermore, loading CeO2@SiO2 core-shell structured particles onto GO sheets utilizes the excellent conductivity of the GO sheets to capture the small number of photogenerated charge carriers escaping from CeO2, further preventing their migration to the polyurethane matrix, thus weakening the photocatalytic oxidation performance of CeO2. Ultimately, this improves the mechanical properties and weather resistance of the coating composition and extends the coating's service life. Attached Figure Description
[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0026] Figure 1 A flowchart illustrating the preparation method of a CeO2 polyurethane composition with ultraviolet shielding function provided in this application.
[0027] Figure 2 This is a physical image of the CeO2@SiO2 core-shell structured particles in Example 1 of this application.
[0028] Figure 3 This is an electron microscope image of the CeO2@SiO2 core-shell structured particles in Example 1 of this application.
[0029] Figure 4 The transmittance of the spectrum of the CeO2 polyurethane composition prepared in Example 1 of this application. Detailed Implementation
[0030] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0031] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.
[0032] The following specific embodiments further illustrate this point:
[0033] Example 1
[0034] like Figure 1 As shown, this embodiment provides a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method:
[0035] 1. 50 nm nano-CeO2, anhydrous ethanol, and deionized water were mixed and stirred at 350 rpm at room temperature for 18 min, followed by sonication at 170 W for 25 min. The pH was adjusted to 4.5 with glacial acetic acid, and then diluted KH-570 was added dropwise over 30 min while maintaining a stirring rate of 380 rpm throughout. The reaction was then carried out at 60 °C with stirring at 600 rpm for 4 h. After centrifugation, washing, and drying, CeO2@SiO2 core-shell structured particles were obtained. The actual product is shown below. Figure 2 As shown, the electron microscope images are as follows: Figure 3 As shown. The mass ratio of the nano CeO2, anhydrous ethanol, deionized water, and diluted KH-570 is 5:160:50:41. The diluted KH-570 is obtained by diluting KH-570 in anhydrous ethanol at a mass ratio of 1:40.
[0036] 2. CeO2@SiO2 core-shell structured particles, anhydrous ethanol, and deionized water were mixed and stirred at 450 rpm for 13 min to prepare a dispersion. GO dispersion was added, and the mixture was stirred at 370 rpm at room temperature for 22 min, followed by sonication at 190 W for 55 min while maintaining stirring at 300 rpm. The mixture was then stirred at 530 rpm at 60℃ for 4.2 h. After centrifugation, washing, and drying, the UV-shielding filler was obtained. The GO dispersion was obtained by adding GO powder to deionized water and sonicating, with a GO powder to deionized water mass ratio of 1:1000. The mass ratio of CeO2@SiO2 core-shell structured particles, anhydrous ethanol, deionized water, and GO dispersion was 5:78.9:50:250. The hydroxyl content of the GO powder was 3 wt.%.
[0037] 3. The UV-shielding filler was added to a polyurethane emulsion with a solid content of 30%, stirred at 500 rpm at room temperature for 12 min, then dispersed at 5500 rpm for 18 min, followed by ultrasonic treatment at 190 W for 17 min. After standing for 72 h without precipitation, SAC-100 crosslinking agent was added, and the mixture was stirred at 260 rpm for 12 min. The emulsion viscosity was adjusted to 240 mPa·s at room temperature to obtain the CeO2 polyurethane composition with UV shielding function described in Example 1. The mass ratio of the UV-shielding filler, polyurethane emulsion, and crosslinking agent was 5:94:1.
[0038] Example 2
[0039] like Figure 1 As shown, this embodiment provides a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method:
[0040] 1. 80nm nano-CeO2, anhydrous ethanol, and deionized water were mixed and stirred at 300rpm at room temperature for 15min, followed by sonication at 150W for 20min. The pH was adjusted to 4 with glacial acetic acid. Then, diluted KH-570 was added dropwise while maintaining a stirring rate of 350rpm throughout the process, completing the addition within 30min. The reaction was then carried out at 55℃ with stirring at 550rpm for 3.5h. After centrifugation, washing, and drying, CeO2@SiO2 core-shell structured particles were obtained. The mass ratio of nano-CeO2, anhydrous ethanol, deionized water, and diluted KH-570 was 4.5:155:55:39. The diluted KH-570 was obtained by diluting KH-570 in anhydrous ethanol at a mass ratio of 1.1:40.
[0041] 2. CeO2@SiO2 core-shell structured particles, anhydrous ethanol, and deionized water were mixed and stirred at 400 rpm for 10 min to prepare a dispersion. GO dispersion was added, and the mixture was stirred at 350 rpm at room temperature for 20 min, followed by sonication at 180 W for 50 min while maintaining stirring at 300 rpm. The mixture was then stirred at 500 rpm at 55℃ for 4 h. After centrifugation, washing, and drying, the UV-shielding filler was obtained. The GO dispersion was obtained by adding GO powder to deionized water and then sonicating; the mass ratio of GO powder to deionized water was 2:1000. The mass ratio of CeO2@SiO2 core-shell structured particles, anhydrous ethanol, deionized water, and GO dispersion was 4.5:78.9:50:225; the hydroxyl content of the GO powder was 3.5 wt.%.
[0042] 3. The UV-shielding filler was added to a polyurethane emulsion with a solid content of 35%, stirred at 450 rpm at room temperature for 10 min, then dispersed at 5000 rpm for 15 min, followed by ultrasonic treatment at 180 W for 15 min. After standing for 72 h without precipitation, RP-1 crosslinking agent was added, and the mixture was stirred at 200 rpm for 10 min. The emulsion viscosity was adjusted to 200 mPa·s at room temperature to obtain the CeO2 polyurethane composition with UV shielding function described in Example 2. The mass ratio of the UV-shielding filler, polyurethane emulsion, and crosslinking agent was 6.5:92:1.5.
[0043] Example 3
[0044] like Figure 1 As shown, this embodiment provides a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method:
[0045] 1. Nano-CeO2 particles (65 nm in diameter), anhydrous ethanol, and deionized water were mixed and stirred at 400 rpm at room temperature for 20 min, followed by sonication at 200 W for 30 min. The pH was adjusted to 5 with glacial acetic acid. Then, diluted KH-570 was added dropwise while maintaining a stirring rate of 400 rpm throughout the process, completing the addition within 30 min. The reaction was then carried out at 65℃ with stirring at 650 rpm for 4.5 h. After centrifugation, washing, and drying, CeO2@SiO2 core-shell structured particles were obtained. The mass ratio of nano-CeO2, anhydrous ethanol, deionized water, and diluted KH-570 was 5.5:150:45:42. The diluted KH-570 was obtained by diluting KH-570 in anhydrous ethanol at a mass ratio of 1.3:40.
[0046] 2. CeO2@SiO2 core-shell structured particles, anhydrous ethanol, and deionized water were mixed and stirred at 500 rpm for 15 min to prepare a dispersion. GO dispersion was added, and the mixture was stirred at 400 rpm at room temperature for 25 min, followed by sonication at 200 W for 60 min while maintaining stirring at 300 rpm. The mixture was then stirred at 550 rpm at 65℃ for 4.5 h. After centrifugation, washing, and drying, the UV-shielding filler was obtained. The GO dispersion was obtained by adding GO powder to deionized water and sonicating, with a GO powder to deionized water mass ratio of 3:1000. The mass ratio of CeO2@SiO2 core-shell structured particles, anhydrous ethanol, deionized water, and GO dispersion was 5.5:78.9:50:275. The hydroxyl content of the GO powder was 3.5 wt.%.
[0047] 3. The UV-shielding filler was added to a polyurethane emulsion with a solid content of 40%, stirred at 550 rpm at room temperature for 15 min, then dispersed at 6000 rpm for 20 min, followed by ultrasonic treatment at 200 W for 20 min. After standing for 72 h without precipitation, Y-2016 crosslinking agent was added, and the mixture was stirred at 300 rpm for 15 min. The emulsion viscosity was adjusted to 300 mPa·s at room temperature to obtain the CeO2 polyurethane composition with UV shielding function described in Example 3. The mass ratio of the UV-shielding filler, polyurethane emulsion, and crosslinking agent was 8:90:2.
[0048] Example 4
[0049] like Figure 1 As shown, this embodiment provides a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method:
[0050] 1. Nano-CeO2 particles with a diameter of 70 nm, anhydrous ethanol, and deionized water were mixed and stirred at 350 rpm at room temperature for 18 min, followed by sonication at 170 W for 25 min. The pH was adjusted to 4.5 with glacial acetic acid. Then, diluted KH-570 was added dropwise while maintaining a stirring rate of 380 rpm throughout the process, completing the addition within 30 min. The reaction was then carried out at 60℃ with a stirring rate of 600 rpm for 4 h. After centrifugation, washing, and drying, CeO2@SiO2 core-shell structured particles were obtained. The mass ratio of nano-CeO2, anhydrous ethanol, deionized water, and diluted KH-570 was 5:160:50:41. The diluted KH-570 was obtained by diluting KH-570 in anhydrous ethanol at a mass ratio of 1:40.
[0051] 2. CeO2@SiO2 core-shell structured particles, anhydrous ethanol, and deionized water were mixed and stirred at 450 rpm for 13 min to prepare a dispersion. GO dispersion was added, and the mixture was stirred at 370 rpm at room temperature for 22 min, followed by sonication at 190 W for 55 min while maintaining stirring at 300 rpm. The mixture was then stirred at 530 rpm at 60℃ for 4.2 h. After centrifugation, washing, and drying, the UV-shielding filler was obtained. The GO dispersion was obtained by adding GO powder to deionized water and sonicating, with a GO powder to deionized water mass ratio of 1:1000. The mass ratio of CeO2@SiO2 core-shell structured particles, anhydrous ethanol, deionized water, and GO dispersion was 5:78.9:50:250. The hydroxyl content of the GO powder was 3 wt.%.
[0052] 3. The UV-shielding filler was added to the polyurethane emulsion and stirred at 500 rpm at room temperature for 12 min. Then, it was dispersed at 5500 rpm for 18 min, followed by ultrasonic treatment at 190 W for 17 min. After standing for 72 h without precipitation, Y-301 crosslinking agent was added, and the mixture was stirred at 260 rpm for 12 min. The emulsion viscosity was adjusted to 240 mPa·s at room temperature to obtain the CeO2 polyurethane composition with UV shielding function described in Example 4. The mass ratio of the UV-shielding filler, polyurethane emulsion, and crosslinking agent was 3:95:2.
[0053] Comparative Example 1
[0054] This comparative example provides a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method. Compared with Example 1, the difference is that a SiO2 passivation film is not coated on the CeO2 surface. The remaining steps are the same as in Example 1 and will not be repeated here.
[0055] Comparative Example 2
[0056] This comparative example provides a CeO2 polyurethane composition with ultraviolet shielding function and its preparation method. Compared with Example 1, the difference is that CeO2@SiO2 core-shell structured particles are not loaded onto GO sheets, but CeO2@SiO2 core-shell structured particles are directly used as ultraviolet shielding fillers. The remaining steps are the same as in Example 1, and will not be repeated here.
[0057] To demonstrate the advantages of this application, UV shielding performance and anti-aging performance tests were conducted on Examples 1-4 and Comparative Examples 1-2.
[0058] Test sample preparation: The CeO2 polyurethane compositions with UV shielding function prepared in Examples 1-4 and Comparative Examples 1-2 were coated onto the substrate, cooled, and then peeled off to obtain the test samples.
[0059] The testing method is as follows:
[0060] Ultraviolet (UV) shielding performance test: The samples were placed in a UV-Vis spectrophotometer for testing. The test wavelength range was 200-800 nm, with a wavelength interval of 10 nm. The transmittance T(λ) of the spectrum at each wavelength was obtained. Based on the spectral transmittance of the 280-400 nm UV band, the average UV transmittance of this band was calculated. The UV shielding efficiency SR(%) was calculated for each group of samples according to the formula: UV shielding efficiency SR(%) = 100% - average UV transmittance. The transmittance curve of the full-band spectrum of Example 1 is shown below. Figure 4 As shown.
[0061] Anti-aging performance test: The sample was placed in a xenon lamp aging test chamber with a xenon lamp irradiation intensity of 1000W / m. 2The samples were continuously irradiated at 40℃ and 50% humidity for 1000 hours, and the morphological changes were observed. The test results are shown in Table 1.
[0062] Table 1. Test results of UV shielding efficiency and anti-aging performance of Examples 1-4 and Comparative Examples 1-2
[0063]
[0064] As shown in Table 1, Examples 1-4 and Comparative Examples 1-2 all exhibit excellent UV shielding performance. This is because CeO2 in the polyurethane composition has good UV absorption capacity, effectively absorbing and shielding most UV rays. Therefore, this also proves that the polyurethane composition prepared in this application has excellent UV shielding performance. However, in terms of anti-aging performance, Comparative Examples 1 and 2 are significantly weaker than Examples 1-4. This is because Comparative Example 1 did not have a SiO2 passivation film during preparation, which led to the oxidative decomposition of the polyurethane matrix by CeO2 under photocatalysis, reducing the service life of the polyurethane matrix and causing premature yellowing and cracking of the coating. Comparative Example 2 did not have a GO sheet loaded, resulting in yellowing of the sample. This may be because a small number of photogenerated carriers escaped from the gaps in the SiO2 passivation film, and the lack of the GO sheet's capture effect on the escaped carriers led to the oxidation of the polyurethane matrix, resulting in yellowing. In summary, the CeO2 polyurethane composition prepared according to this application has excellent UV shielding and anti-aging properties, and can be applied to fields such as UV-resistant outdoor coatings and UV-resistant textile finishing agents.
[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the claims of this application.
Claims
1. A CeO2 polyurethane composition with ultraviolet shielding function, characterized in that, The composition includes a UV-shielding filler, an aqueous polyurethane emulsion, and a crosslinking agent; the UV-shielding filler is obtained by generating a SiO2 passivation layer in situ on the surface of nano-CeO2 to obtain CeO2@SiO2 core-shell structured particles, and then uniformly loading the CeO2@SiO2 core-shell structured particles onto the surface of GO sheets.
2. The CeO2 polyurethane composition with ultraviolet shielding function according to claim 1, characterized in that, The solid content of the waterborne polyurethane emulsion is 30-40%.
3. The CeO2 polyurethane composition with ultraviolet shielding function according to claim 1, characterized in that, The crosslinking agent is any one of SAC-100, RP-1, Y-2016 and Y-301.
4. A method for preparing a CeO2 polyurethane composition with ultraviolet shielding function as described in any one of claims 1-3, characterized in that, Includes the following steps: S1, mix nano CeO2, anhydrous ethanol and deionized water, stir and sonicate, adjust the pH to 4-5, add diluted silane coupling agent dropwise, and react to obtain CeO2@SiO2 core-shell structured particles; S2, CeO2@SiO2 core-shell structured particles were prepared into a dispersion, GO dispersion was added, stirred and sonicated, and reacted at a constant temperature to obtain the ultraviolet shielding filler; S3, UV-shielding filler is added to polyurethane emulsion, stirred and impregnated, dispersed at high speed, ultrasonically treated, crosslinking agent is added, and stirred and mixed to obtain a CeO2 polyurethane composition with UV shielding function.
5. The method for preparing a CeO2 polyurethane composition with ultraviolet shielding function according to claim 4, characterized in that, The specific process of S1 is as follows: nano CeO2, anhydrous ethanol and deionized water are mixed and stirred at 300-400 rpm at room temperature for 15-20 min, followed by ultrasonication at 150-200W power for 20-30 min, and the pH is adjusted to 4-5. Then, diluted silane coupling agent is added dropwise while maintaining a stirring rate of 350-400 rpm throughout the process. The addition is completed within 30 min. Then, the reaction is carried out at 55-65℃ and a stirring rate of 550-650 rpm for 3.5-4.5 h. After centrifugation, washing and drying, CeO2@SiO2 core-shell structured particles are obtained.
6. The method for preparing a CeO2 polyurethane composition with ultraviolet shielding function according to claim 4, characterized in that, The silane coupling agent diluted in S1 is obtained by diluting KH-570 in anhydrous ethanol at a mass ratio of (1-1.3):
40.
7. The method for preparing a CeO2 polyurethane composition with ultraviolet shielding function according to claim 4, characterized in that, The mass ratio of nano CeO2, anhydrous ethanol, deionized water and diluted silane coupling agent in S1 is (4.5-5.5):(150-160):(45-55):(39-42).
8. The method for preparing a CeO2 polyurethane composition with ultraviolet shielding function according to claim 4, characterized in that, The specific process of S2 is as follows: CeO2@SiO2 core-shell structured particles, anhydrous ethanol and deionized water are mixed and stirred at 400-500 rpm for 10-15 min to prepare a dispersion. GO dispersion is added and stirred at 350-400 rpm at room temperature for 20-25 min. The mixture is then sonicated at 180-200W power for 50-60 min while maintaining stirring at 300 rpm. The mixture is then stirred at 500-550 rpm at 55-65℃ for 4-4.5 h. After centrifugation, washing and drying, the UV-shielding filler is obtained. The GO dispersion is obtained by adding GO powder to deionized water and sonicating. The mass ratio of GO powder to deionized water is (1-3):1000.
9. The method for preparing a CeO2 polyurethane composition with ultraviolet shielding function according to claim 8, characterized in that, The mass ratio of CeO2@SiO2 core-shell structured particles, anhydrous ethanol, deionized water and GO dispersion in S2 is (4.5-5.5):78.9:50:(225-275).
10. The method for preparing a CeO2 polyurethane composition with ultraviolet shielding function according to claim 4, characterized in that, The specific process of S3 is as follows: the ultraviolet shielding filler is added to the polyurethane emulsion, stirred at 450-550 rpm at room temperature for 10-15 min, then dispersed at 5000-6000 rpm for 15-20 min, then ultrasonically treated at 180-200W power for 15-20 min, and allowed to stand for 72 h. If no precipitation occurs, a crosslinking agent is added, and the mixture is stirred at 200-300 rpm for 10-15 min. The viscosity of the emulsion is adjusted to 200-300 mPa·s at room temperature to obtain a CeO2 polyurethane composition with ultraviolet shielding function. The mass ratio of the ultraviolet shielding filler, polyurethane emulsion and crosslinking agent is (5-8):(90-95):(1-2).