Anti-ultraviolet nano material as well as preparation method and application thereof

Abstract

The invention discloses an anti-ultraviolet nano-material, which is characterized in that nano-spheres with uniform and controllable size and anti-ultraviolet capability are prepared by utilizing reverse microemulsion polymerization reaction and adopting a one-pot method. The preparation process is simple, the process is safe, and the use of halogen compounds is not involved. Only 1-5wt% of the nanospheres prepared by the invention are added, so that the waterborne epoxy coating has enhanced mechanical properties and ultraviolet resistance.

Description

Technical Field

[0001] This invention belongs to the field of waterborne epoxy coating modification, specifically relating to an anti-ultraviolet nanomaterial, its preparation method, and its application. Background Technology

[0002] Waterborne epoxy coatings are environmentally friendly coatings that use water as the dispersion medium. While retaining the excellent properties of traditional solvent-based epoxy resins, they significantly reduce harm to the environment and human health. They have a wide range of applications, especially in industrial flooring, such as factory workshops, warehouses, and parking lots, providing protection against wear, pressure, and chemical corrosion. However, they also have some inherent limitations, so in practical applications, modification is often necessary to further improve their performance to meet more stringent usage requirements.

[0003] Currently, copolymerization modification and blending modification are two commonly used methods for modifying waterborne epoxy resins. Blending modification involves physically mixing other fillers with epoxy resin, utilizing the properties of different fillers to impart different functions to the waterborne epoxy resin. This is a simple, practical, and easily industrialized method. To improve the mechanical, electrical, thermal, magnetic, optical, and flame-retardant properties of epoxy resins, various nanofillers and additives, including iron and iron oxide nanoparticles, carbon nanofibers, graphene, nanoclay, polyaniline, silica, zinc oxide, and alumina, have been used for the functionalization of epoxy nanocomposites. However, the limitations of traditional nanofillers in dispersibility, interfacial compatibility, and multifunctional integration often result in toughening fillers lacking UV shielding capabilities, while UV-resistant fillers may induce stress concentration and reduce toughness. Summary of the Invention

[0004] Addressing the challenge that existing waterborne epoxy coatings cannot simultaneously achieve both UV resistance and high toughness, this invention provides a UV-resistant nanomaterial, its preparation method, and its applications. Through a reverse microemulsion polymerization reaction, nanospheres with uniform and controllable dimensions and UV resistance are prepared in a one-pot process. These nanospheres exhibit excellent UV resistance and can also act as stress concentration points in waterborne epoxy resin coated composites. By inducing crazes, pinning and deflecting crack paths, they effectively dissipate impact energy, significantly improving toughness without sacrificing modulus.

[0005] One of the technical solutions of this invention is to provide an anti-ultraviolet nanomaterial, wherein the nanomaterial has a core-shell structure, the core being a mixture of an anti-ultraviolet material and silica, and the shell being silica, wherein the anti-ultraviolet material is 2-phenylbenzimidazole-5-sulfonic acid. The silica shell has a mesoporous structure, allowing ultraviolet light to penetrate and enabling the 2-phenylbenzimidazole-5-sulfonic acid molecules to absorb ultraviolet light.

[0006] The second technical solution of the present invention is to provide a method for preparing an anti-ultraviolet nanomaterial, which specifically includes the following steps: (1) Mixing 1.77g Triton-100, 6.5ml cyclohexane, 1.8ml n-hexanol, 2mg 2-phenylbenzimidazole-5-sulfonic acid and 480ul water evenly to obtain a reverse microemulsion; (2) Add 20-50 μL of concentrated ammonia to the reverse microemulsion, stir for 30 minutes, add 100 μL of silanizing reagent, and continue stirring for 24 hours to obtain a mixed solution; the silanizing reagent is one of tetraethyl orthosilicate, (3-aminopropyl)triethoxysilane, and isobutyltriethoxysilane. (3) Add acetone to the mixed solution and collect the UV-resistant nanomaterials by centrifugation.

[0007] Furthermore, the stirring speed for uniform mixing in step 1 is 750 r / min.

[0008] The third technical solution of the present invention is to provide the application of the above-mentioned nanomaterials.

[0009] Specifically, UV-resistant nanomaterials are blended with waterborne epoxy resin, and then a curing agent is added and hot-pressed to obtain a UV-resistant waterborne epoxy resin coating composite material; wherein the content of UV-resistant nanomaterials is 1~5wt%.

[0010] Furthermore, the hot pressing is performed using a flat vulcanizing machine, with a hot pressing temperature of 175°C and a pressure of 10 MPa.

[0011] The advantages of this invention are: by using reverse microemulsion polymerization, nanoparticles with uniform and controllable size and UV resistance are prepared in a one-pot method, achieving a synergistic effect of toughening and UV resistance, and solving the problem of difficulty in preparing core-shell structures with controllable size and adjustable composition.

[0012] Uniformly dispersed nanospheres of uniform size can act as stress concentration points in waterborne epoxy resin coated composites. By inducing crazes, pinning and deflecting crack paths, they can effectively dissipate impact energy and significantly improve toughness without sacrificing modulus.

[0013] Furthermore, while 2-phenylbenzimidazole-5-sulfonic acid, a highly water-soluble organic UV absorber, possesses excellent UV-B absorption capabilities, its easy migration and rapid photodegradation severely limit its practical applications. By encapsulating it with a core-shell structure, the silica shell forms a physical barrier, effectively preventing the diffusion of 2-phenylbenzimidazole-5-sulfonic acid molecules to the outside environment, especially significantly inhibiting its dissolution in aqueous environments. Simultaneously, the shell isolates oxygen and moisture, slowing down the oxidative degradation process under light and greatly improving its photochemical stability. More importantly, the silica shell has a mesoporous structure, allowing ultraviolet light to penetrate and activate the 2-phenylbenzimidazole-5-sulfonic acid molecules within the core, enabling them to efficiently absorb ultraviolet light, thus achieving long-lasting protection without sacrificing functionality. Attached Figure Description

[0014] Figure 1 The images show the SEM characterization and EDS imaging of the nanospheres, as well as the thermogravimetric characterization of the nanospheres.

[0015] Figure 2 Images showing the stability of an aqueous epoxy emulsion after one month of storage.

[0016] Figure 3 To demonstrate the toughening and UV resistance of the nanospheres, the pink line in the left figure represents tensile strength, and the blue line represents elongation at break; the right figure shows the UV resistance of Example 1, where red represents the waterborne epoxy resin coating composite material doped with nanospheres, and blue lines represent waterborne epoxy resin.

[0017] Figure 4 For toughening and UV protection. Detailed Implementation

[0018] The following examples are provided to further illustrate the present invention and are intended to explain the invention, not to limit its scope. Unless otherwise specified, all figures are expressed in parts by weight and weight percentages.

[0019] Unless otherwise specified, the raw materials used in this invention are all conventional commercially available products; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0020] In this invention, the curing agent used is a conventional choice in the art, such as modified fatty amines, polyamides, or latent curing agents.

[0021] The ultraviolet absorption performance was tested at 300 nm.

[0022] The embodiments of the present invention will be further described below with reference to several examples.

[0023] The concentration of the concentrated ammonia solution described in this invention is 25 wt% to 28 wt%.

[0024] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0025] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0026] Example 1 (1) Mix 1.77g Triton-100, 6.5ml cyclohexane, 1.8ml n-hexanol, 2mg 2-phenylbenzimidazole-5-sulfonic acid and 480ul water at 750r / min to obtain a reverse microemulsion; (2) Add concentrated ammonia to the reverse microemulsion, stir for 30 minutes, then add 100 μL of tetraethyl orthosilicate, and continue stirring for 24 hours to obtain a mixed solution; (3) Add acetone to the mixed solution and collect the UV-resistant nanomaterials by centrifugation.

[0027] (4) 1 part by weight of UV-resistant nanomaterials is blended with 99 parts by weight of waterborne epoxy resin, and then a curing agent is added. The mixture is then hot-pressed to obtain a UV-resistant waterborne epoxy resin coating composite material. Figure 3 It can be seen that the transmittance of waterborne epoxy resin with added UV-resistant nanomaterials is significantly reduced, achieving a complete shielding effect against ultraviolet light at 300nm.

[0028] Example 2 The difference from Example 1 is that the mass ratio of the UV-resistant nanomaterial to the waterborne epoxy resin is 3:97.

[0029] Example 3 (1) Mix 1.77g Triton-100, 6.5ml cyclohexane, 1.8ml n-hexanol, 2mg 2-phenylbenzimidazole-5-sulfonic acid and 480ul water at 750r / min to obtain a reverse microemulsion; (2) Add concentrated ammonia to the reverse microemulsion, stir for 30 minutes, then add 100 μL of tetraethyl orthosilicate, and continue stirring for 24 hours to obtain a mixed solution; (3) Add acetone to the mixed solution and collect the UV-resistant nanomaterials by centrifugation.

[0030] (4) 5 parts by weight of UV-resistant nanomaterials are blended with 95 parts by weight of waterborne epoxy resin, and then a curing agent is added. The mixture is then hot-pressed to obtain a UV-resistant waterborne epoxy resin coating composite material.

[0031] like Figure 2 As shown, the aqueous emulsion after blending nanospheres with aqueous epoxy resin exhibits good stability, and no obvious separation or stratification was observed after one month of storage.

[0032] like Figure 3 As shown, when the mass ratio of nanospheres to waterborne epoxy resin is 3:97, the prepared waterborne epoxy resin coating composite material exhibits the best strength performance and the highest elongation at break, approaching 10%.

[0033] Comparative Example 1 A waterborne epoxy resin is blended, and then a curing agent is added. The mixture is then hot-pressed to obtain a waterborne epoxy resin coating material.

[0034] Comparative Example 2 Five parts by weight of silica were blended with 95 parts by weight of waterborne epoxy resin, and then a curing agent was added. The mixture was then hot-pressed to obtain a waterborne epoxy resin coated composite material. The ultraviolet absorption performance of Example 1 and Comparative Example 2 at a wavelength of 300 nm was tested. Figure 4 As shown, the light transmittance of Example 1 is significantly lower than that of Comparative Example 2.

[0035] Comparative Example 3 Five parts by weight of 2-phenylbenzimidazole-5-sulfonic acid were blended with 95 parts by weight of waterborne epoxy resin, and then a curing agent was added. The mixture was then hot-pressed to obtain a waterborne epoxy resin coated composite material.

[0036] Comparative Example 4 Two parts by weight of silica, three parts by weight of 2-phenylbenzimidazole-5-sulfonic acid, and ninety-five parts by weight of waterborne epoxy resin were blended together, and then a curing agent was added. The mixture was then hot-pressed to obtain a waterborne epoxy resin coated composite material.

[0037] like Figure 4 As shown, the toughness of Comparative Examples 3 and 4 was significantly reduced compared to Example 1. This indicates that simply combining silica and UV stabilizers results in poor compatibility with the system, which significantly affects the toughness of the material.

[0038] The above embodiments describe in detail the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall still fall within the scope of protection of the present invention if they do not exceed the scope covered by the specification.

Claims

1. A UV-resistant nanomaterial, characterized in that, The nanomaterial has a core-shell structure, with the core being silicon dioxide loaded with an anti-UV material and the shell being silicon dioxide. The anti-UV material is 2-phenylbenzimidazole-5-sulfonic acid. The silicon dioxide shell has a mesoporous structure, allowing ultraviolet light to penetrate and enabling the 2-phenylbenzimidazole-5-sulfonic acid molecules to absorb ultraviolet light.

2. A method for preparing the UV-resistant nanomaterial as described in claim 1, characterized in that, It includes the following steps: (1) Mix 1.77g Triton-100, 6.5ml cyclohexane, 1.8ml n-hexanol, 2mg 2-phenylbenzimidazole-5-sulfonic acid and 480ul water evenly to obtain a reverse microemulsion; (2) Add 20-50 μL of concentrated ammonia to the reverse microemulsion, stir for 30 minutes, add 100 μL of silanizing reagent, and continue stirring for 24 hours to obtain a mixed solution; The silanizing agent is one of tetraethyl orthosilicate, (3-aminopropyl)triethoxysilane, and isobutyltriethoxysilane; (3) Add acetone to the mixed solution and collect the UV-resistant nanomaterials by centrifugation.

3. The preparation method according to claim 2, characterized in that, The stirring speed for mixing in step 1 is 750 r / min.

4. An application of the nanomaterial as described in claim 3.

5. The application according to claim 4, characterized in that, UV-resistant nanomaterials are blended with waterborne epoxy resin, and then a curing agent is added. The mixture is then hot-pressed to obtain a UV-resistant waterborne epoxy resin coating composite material. The content of UV-resistant nanomaterials is 1-5 wt%.

6. The application according to claim 5, characterized in that, The hot pressing is performed using a flat vulcanizing machine at a temperature of 175°C and a pressure of 10 MPa.

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