A self-healing polymer material with both high visible light transmittance and full ultraviolet light blocking properties, its preparation method and applications.

Abstract

This invention discloses a self-healing polymer material possessing both high visible light transmittance and full ultraviolet light blocking properties, its preparation method, and its applications. The polymer material contains aromatic Schiff base bonds, which are located at any one or more positions among the polymer network crosslinking sites, the polymer backbone, the polymer side chains, and the branched polymer chains. The aromatic Schiff base bonds form a continuous conjugated structure with strong absorption in the 200-400 nm ultraviolet region, thus exhibiting excellent full ultraviolet light blocking properties. Furthermore, the aromatic Schiff base bonds show no absorption in the 500-800 nm visible light region, and the polymer material is amorphous and non-crystalline, thus also possessing high visible light transmittance. The polymer material achieves a transmittance of over 90% at a visible light wavelength of 550 nm and a UV blocking rate of 100% in the 200-400 nm ultraviolet region. Since the aromatic Schiff base bonds are dynamic covalent bonds, the polymer material also possesses solvent-assisted room-temperature self-healing capabilities.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a self-healing polymer material that combines high visible light transmittance and full ultraviolet light blocking properties, its preparation method, and its uses. Background Technology

[0002] Transparent polymer materials are widely used in pillar industries of the national economy and high-tech fields. They not only make materials more aesthetically pleasing but also allow users to observe other objects more clearly. Furthermore, long-term and excessive exposure to ultraviolet (UV) radiation can cause significant damage to the human body, greatly shorten the lifespan of polymer materials, and lead to nutrient loss in food. Therefore, polymer materials with UV-blocking properties are indispensable.

[0003] Currently, there are three main methods for constructing polymer materials with UV blocking properties: composite materials, polymer structure design, and polymer surface modification. Composite materials refer to incorporating traditional organic UV absorbers (such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, and triazines), inorganic metal oxides, inorganic UV shielding agents, natural / modified compounds (such as lignin, modified lignin, and modified nanocellulose), and synthetic polymers (such as polyphosphoric acid and sulfur-natural rosin copolymers) into a polymer matrix. Polymer structure design involves introducing UV-absorbing groups (such as benzotriazole side chains and furan groups) into polymer materials through copolymerization, polycondensation, etc. Polymer surface modification involves introducing UV-absorbing groups onto the polymer surface through chemical reactions, etc. However, none of these strategies can achieve both high visible light transmittance (transmittance greater than 90% at 550nm) and full UV blocking (100% UV blocking in the 200-400nm UV range) in polymer materials.

[0004] Furthermore, with the increasing emphasis on the circular economy, self-healing polymer materials are receiving more and more attention. On the one hand, they have a longer service life; on the other hand, they are easier to recycle than traditional thermosetting polymers. Researchers have also focused on the self-healing capabilities of existing polymer materials with UV-blocking properties. However, the self-healing function of these polymer materials requires high temperature or high-temperature catalytic conditions to be realized. These harsh self-healing conditions may cause polymer thermal degradation and catalyst quenching.

[0005] Based on the above, this invention proposes a self-healing polymer material that combines high visible light transmittance and full ultraviolet light blocking, its preparation method, and its uses, which can solve the above problems. Summary of the Invention

[0006] To meet the broader application needs of polymer materials in fields such as transparent UV-resistant films / coatings, transparent packaging materials, greenhouse films, and high-efficiency UV-resistant solar cell encapsulation films, there is an urgent need to develop a self-healing polymer material that combines high visible light transmittance with full UV light blocking.

[0007] The purpose of this invention is to provide a self-healing polymer material that combines high visible light transmittance and full ultraviolet light blocking, its preparation method, and its applications, in order to solve the technical problems of existing polymer materials that are difficult to achieve both high visible light transmittance (transmittance greater than 90% at 550nm visible light wavelength) and full ultraviolet light blocking (100% ultraviolet blocking rate in the 200-400nm ultraviolet range), and the difficulty of achieving room temperature self-healing in ultraviolet-blocking polymer materials. It mainly includes the following three aspects.

[0008] The first aspect of this invention provides a self-healing polymer material that combines high visible light transmittance with full ultraviolet light blocking properties, wherein the polymer material contains aromatic Schiff base bonds. The aromatic Schiff base bond is formed by the reaction of the phenylamino group in a polymer containing a phenylamino group and the benzaldehyde group in a compound containing a benzaldehyde group.

[0009] Furthermore, the aromatic Schiff base bond is formed by the reaction of the phenylamino group in the polymer containing the phenylamino group and the benzaldehyde group of the aromatic polyaldehyde with a functionality f≥2, and the temperature of the aromatic Schiff base bond is 10-80℃; preferably, 21-80℃.

[0010] Furthermore, the polymer material has high visible light transmittance, that is, the transmittance at a visible light wavelength of 550nm reaches more than 87%, preferably more than 90%; the polymer material also has full ultraviolet light blocking properties, that is, the ultraviolet blocking rate in the 200-400nm ultraviolet range reaches 100%.

[0011] Furthermore, the molar fraction of aromatic Schiff base bonds in the polymer material is greater than 5 mol%; preferably, the molar fraction of aromatic Schiff base bonds in the polymer material is greater than 25 mol%.

[0012] Furthermore, the polymer material possesses solvent-assisted room temperature self-healing function, wherein the solvent is selected from any one of N,N-dimethylformamide and dimethyl sulfoxide.

[0013] Furthermore, the aromatic Schiff base bond is located at any one or more positions in the polymer backbone, polymer network crosslinking sites, polymer branched chains, and polymer side chains; when r 1 and r 2 When the aromatic Schiff bases are selected from polymer molecular chains and respectively attached to a substitution site on the benzene ring, the aromatic Schiff bases are located inside the polymer backbone; when r1 Selected from polymer molecular chains, r 2 Selected from any other suitable group, hydrogen atom or other substituted atom, or r 1 Selected from any other suitable group, hydrogen atom or other substituent atom, r 2 When the aromatic Schiff bases are selected from polymer molecular chains and respectively attached to a substitution site on the benzene ring, the aromatic Schiff bases are located at the end of the polymer backbone or on the side chain; when r 1 and r 2 Selected from polymer molecular chains, and r 1 Connected to a substitution site on the benzene ring, r 2 Connected at at least two substitution sites on the benzene ring, or r 1 Connected at at least two substitution sites on the benzene ring, r 2 When linked to a substitution site on the benzene ring, aromatic Schiff base bonds are located at polymer network crosslinking sites or in polymer branched chains; when r 1 Selected from polymer molecular chains, r 2 Selected from any other suitable group, hydrogen atom or other substituted atom, or r 1 Selected from any other suitable group, hydrogen atom or other substituent atom, r 2 When the aromatic Schiff base is selected from the polymer molecular chain and is respectively attached to at least one substitution site on the benzene ring, the aromatic Schiff base bond is located on the polymer side chain.

[0014] Furthermore, the molding method of the polymer material is any one or more of the following: casting, spraying, dipping, brushing, spin coating, and hot pressing.

[0015] Furthermore, the polymer material, after molding, is selected from elastomers, gels, and ordinary solid polymers.

[0016] Furthermore, the thickness of the polymer material is greater than 1 μm; preferably, it is greater than 50 μm.

[0017] Furthermore, the structure of polymers containing phenylamino groups is as follows:

[0018] R1 is R2 is R3 is R4 is Or O, R5 is H, F, Cl, Br, I, -CN, -CH3, -CF3, -OCH3, -OCF3, -COOH or OH, (R6, R7) are saturated alkyl groups with 1 to 6 carbon atoms, m = 6 to 60, n = 1 to 5, p = 1 to 3, q ​​= 2 to 20, r = 1 to 3, t = 1 to 60, x = 6 to 100.

[0019] Furthermore, the structure of compounds containing benzaldehyde groups is as follows:

[0020]

[0021]

[0022] R8 can be H, F, Cl, Br, I, -CN, -CH3, -CF3, -OCH3, -OCF3, -COOH or OH, and A can be C or N.

[0023] A second aspect of the present invention is to provide a method for preparing the above-mentioned polymer material, comprising the following steps: dropping a solution of a compound containing a benzaldehyde group into a solution of a polymer containing a phenylamino group, stirring until the reaction is complete, so that the molar ratio of the benzaldehyde group to the phenylamino group is 1:1; casting the solution after the reaction is complete and evaporating the dry solvent, and drying to obtain the polymer material.

[0024] Furthermore, in the preparation process, the solvent used for the compound solution containing benzaldehyde groups and the polymer solution containing phenylamino groups is any one or more of dichloromethane, dichloroethane, trichloromethane, tetrahydrofuran, toluene, N,N-dimethylformamide, and dimethyl sulfoxide.

[0025] A third aspect of the present invention is to provide an application of the above-mentioned polymer material, wherein the polymer material is used to prepare transparent UV-resistant films / coatings, transparent packaging materials, greenhouse films, high-efficiency UV-resistant solar cell encapsulation films, etc.

[0026] Compared with the prior art, the present invention has at least the following technical effects:

[0027] This invention introduces aromatic Schiff base bonds into polymer materials. On one hand, the aromatic Schiff base bond is a continuous conjugated structure that absorbs across the entire ultraviolet region (200-400 nm), thus endowing the polymer material with full ultraviolet light blocking properties (100% UV blocking in the 200-400 nm ultraviolet range). Furthermore, the aromatic Schiff base bond has no absorption in the visible light region (500-800 nm), while ensuring that the polymer material has no crystalline regions and remains in an amorphous state. Therefore, the polymer material also exhibits high visible light transmittance (transmittance greater than 87% at 550 nm, preferably greater than 90%). On the other hand, the aromatic Schiff base bond is a dynamic covalent bond, thus enabling the polymer material to possess solvent-assisted room-temperature self-healing capabilities.

[0028] This invention introduces dynamic covalent aromatic Schiff base bonds with continuous conjugated structures into polymer materials through polymer structure design. Compared with previously reported techniques for constructing polymer materials with UV blocking properties, it has the following advantages: (1) Compared with polymer materials with UV blocking properties constructed through polymer structure design, the polymer material provided by this invention can effectively balance high visible light transmittance (transmittance of more than 87% at a visible light wavelength of 550nm, preferably greater than 90%) and full UV blocking (UV blocking rate of 100% in the 200-400nm UV range). (2) Compared with composite material systems, the polymer material provided by this invention avoids the problems of poor compatibility between components in composite systems of inorganic metal oxides, inorganic UV shielding agents, natural / modified compounds and polymer substrates, which leads to material opacity, and the easy loss of organic small molecule UV absorbers during use in composite systems of organic small molecule UV absorbers and polymer substrates. (3) Previous studies have also modified polymer surfaces through chemical reactions (such as the Hantzsch reaction) to distribute ultraviolet-absorbing groups (such as 1,4-dihydropyridine groups) on the polymer surface, thereby endowing the polymer material with ultraviolet blocking properties. However, such polymer materials are difficult to maintain ultraviolet blocking properties after the surface is damaged. In contrast, the polymer material provided by this invention has aromatic Schiff base bonds distributed internally, and it still maintains ultraviolet blocking properties even if the material surface is damaged. Compared with the reported techniques for constructing self-healing polymer materials with ultraviolet blocking properties, it has the following advantages: Previously, polymer materials with ultraviolet blocking properties required high temperature or high temperature catalyst conditions to achieve self-healing function, and the harsh self-healing conditions may cause polymer thermal degradation and catalyst quenching. In contrast, the polymer material provided by this invention has dynamically distributed covalent aromatic Schiff base bonds in its network. Since aromatic Schiff base bonds have dynamic exchangeability at room temperature, the polymer material can achieve room temperature self-healing function with solvent assistance. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below.

[0030] Figure 1 Optical photographs of the polymer materials prepared in Examples 1-7;

[0031] Figure 2 The images show the ultraviolet-visible transmission spectra of the polymer materials prepared in Examples 1-7.

[0032] Figure 3 Optical photographs of several polymer materials of different thicknesses prepared in Example 8;

[0033] Figure 4The images show the UV-Vis transmission spectra of polymer materials of different thicknesses prepared in Example 8.

[0034] Figure 5 To demonstrate the optical stability of the polymer material described in Example 9 under prolonged high temperatures;

[0035] Figure 6 The optical stability of the polymer material described in Example 9 under long-term ultraviolet irradiation;

[0036] Figure 7 These are micrographs of the self-healing process of samples 1-4 in Example 10 under the assistance of N,N-dimethylformamide;

[0037] Figure 8 These are micrographs of the self-healing process of samples 1-4 in Example 10 under the assistance of dimethyl sulfoxide;

[0038] Figure 9 An optical photograph of the visible light transmittance and ultraviolet blocking properties of the polymer material-eyeglass lens composite in Example 11;

[0039] Figure 10 This is a comparison of the UV-Vis transmission spectra of the polymer-glass composite and the pure glass sheet in Example 11;

[0040] Figure 11 The UV-Vis absorption spectrum of a model small molecule (trifunctional) containing aromatic Schiff base bonds;

[0041] Figure 12 The UV-Vis absorption spectrum of a model small molecule (bifunctional) containing aromatic Schiff base bonds;

[0042] Figure 13 An optical photograph of the 3M film-glass composite prepared in Example 12;

[0043] Figure 14 This is a comparison of the UV-Vis transmission spectra of the 3M film-glass composite and the pure glass sheet prepared in Example 12.

[0044] Figure 15 This is a comparison diagram of the optical properties of the polymer material of this invention with those of existing technologies;

[0045] Figure 16 This is a comparison chart of the performance of the polymer material of this invention and commercially available 3M transparent UV-protective automotive film. Detailed Implementation

[0046] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0047] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Furthermore, it should be understood that after reading the disclosure of this invention, those skilled in the art can make various modifications or alterations to the present invention, and these equivalent forms also fall within the scope of protection defined by this invention.

[0048] Test Method: UV-Vis absorption and transmission spectra were measured on a Shimadzu UV-3600i Plus UV-Vis spectrophotometer equipped with an integrating sphere. Sample dimensions were 2-5 cm in length and 2-3 cm in width. Air was used as the background during testing, and each test was repeated at least three times. The formula for calculating the UV blocking rate in the entire UV region is: UV blocking rate in the entire UV region,

[0049] This invention comprises 12 embodiments. In Examples 1, 2, 3, and 4, the aromatic Schiff base bonds in the polymer materials are all located at the crosslinking sites of the polymer network. In Example 5, the aromatic Schiff base bonds in the polymer material are located at the ends of the polymer backbone. In Example 6, the polymer material does not contain aromatic Schiff base bonds. In Example 7, the polymer material uses non-aromatic Schiff base bonds as crosslinking points. Example 8 illustrates the effect of the thickness of the polymer material described in Example 1 on its optical properties. Example 9 demonstrates the optical stability of the polymer material described in Example 1 under prolonged high temperature and ultraviolet irradiation. Example 10 illustrates the solvent-assisted room temperature self-healing function of the polymer materials described in Examples 1, 2, 3, and 4. Example 11 illustrates the application of the polymer material described in Example 8 in transparent, high-efficiency, ultra-thin, self-healing films (automotive films and eyeglass films, etc.). Example 12 illustrates the optical properties of two commercially available 3M transparent ultraviolet-blocking automotive films. The 12 embodiments are described in detail below.

[0050] In the following examples, the isophorone diisocyanate has the following structural formula: polyetheramine structural formula (Molecular weight is 2000), the structural formula of 4,4′-diaminodiphenylmethane is: The structural formula of pyromellitic methyl ester is: The structural formula of 4,4′-diaminodiphenyldisulfide is: The structural formula of p-methylbenzaldehyde is

[0051] Example 1

[0052] 1. Add 444.5 mg (2 mmol, 4 mmol isocyanate group) of isophorone diisocyanate dissolved in 20 mL of dichloromethane to a nitrogen-protected flask. Then add 2 g (1 mmol, 2 mmol amino) of polyetheramine dissolved in 10 mL of dichloromethane dropwise to the flask. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the first mixed solution with isocyanate group end groups.

[0053] 2. Dissolve 396.5 mg (2 mmol, 4 mmol phenylamino group) of 4,4′-diaminodiphenylmethane in 10 mL of dichloromethane. Under the protection of nitrogen atmosphere and stirring at room temperature, add the first mixed solution obtained in step 1 dropwise to the dichloromethane solution of 4,4′-diaminodiphenylmethane. After the addition is complete, continue stirring for 8 h to ensure that the reaction is complete, and obtain the second mixed solution with phenylamino group at the end.

[0054] 3. Dissolve 108.1 mg (0.67 mmol, 2 mmol benzaldehyde group) of trimesin in 10 mL of dichloromethane. While stirring at room temperature, add the trimesin dichloromethane solution dropwise to the second mixed solution obtained in step 2. After the addition is complete, continue stirring for 48 h to allow the reaction to proceed fully, and obtain the third mixed solution.

[0055] 4. The third mixed solution described in step 3 is poured into a glass petri dish. After the solvent evaporates at room temperature with a humidity of 20%–35%, it is then vacuum dried at 50–80°C for 48 hours to obtain the polymer material containing aromatic Schiff base bonds, with the following structure:

[0056]

[0057] It was named Sample 1 and had a thickness of approximately 420 μm.

[0058] In Example 1, the molar fraction of aromatic Schiff base bonds was 200 mol%.

[0059] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 1, the polymer material exhibits high transmittance of visible light.

[0060] The polymer material obtained in Example 1 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 As shown in Sample 1. Sample 1 has a transmittance of 91% at a visible light wavelength of 550 nm and an ultraviolet blocking rate of 100% in the entire ultraviolet region.

[0061] Example 2

[0062] 1. Add 444.5 mg (2 mmol, 4 mmol isocyanate group) of isophorone diisocyanate dissolved in 20 mL of dichloromethane to a nitrogen-protected flask. Then add 2 g (1 mmol, 2 mmol amino) of polyetheramine dissolved in 10 mL of dichloromethane dropwise to the flask. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the first mixed solution with isocyanate group end groups.

[0063] 2. Dissolve 62.1 mg (0.25 mmol, 0.5 mmol amino) 4,4′-diaminodiphenyl disulfide in 10 mL of dichloromethane. Under a nitrogen atmosphere and with stirring at room temperature, add the dichloromethane solution of 4,4′-diaminodiphenyl disulfide dropwise to the first mixed solution obtained in step 1. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the second mixed solution.

[0064] 3. Dissolve 297.4 mg (1.5 mmol, 3.0 mmol phenylamino group) of 4,4′-diaminodiphenylmethane in 10 mL of dichloromethane. Under the protection of nitrogen atmosphere and stirring at room temperature, add the second mixed solution obtained in step 2 dropwise to the dichloromethane solution of 4,4′-diaminodiphenylmethane. After the addition is complete, continue stirring for 8 h to ensure that the reaction is complete, and obtain the third mixed solution with phenylamino group at the end.

[0065] 4. Dissolve 81.1 mg (0.5 mmol, 1.5 mmol benzaldehyde group) of trimesin in 10 mL of dichloromethane. While stirring at room temperature, add the trimesin dichloromethane solution dropwise to the third mixed solution obtained in step 3. After the addition is complete, continue stirring for 48 h to allow the reaction to proceed fully, and obtain the fourth mixed solution.

[0066] 5. The fourth mixed solution described in step 4 is poured into a glass petri dish. After the solvent evaporates at room temperature with a humidity of 20%–35%, it is then vacuum dried at 50–80°C for 48 hours to obtain the polymer material containing aromatic Schiff base bonds, with the following structure:

[0067]

[0068] It was named Sample 2 and had a thickness of approximately 420 μm.

[0069] In Example 2, the molar fraction of aromatic Schiff base bonds was 150 mol%.

[0070] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 2, the polymer material has high visible light transmittance.

[0071] The polymer material obtained in Example 2 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 As shown in Sample 2, Sample 2 has a transmittance of 87.7% at a visible wavelength of 550 nm and an ultraviolet blocking rate of 100% in the entire ultraviolet region.

[0072] Example 3

[0073] 1. Add 444.5 mg (2 mmol, 4 mmol isocyanate group) of isophorone diisocyanate dissolved in 20 mL of dichloromethane to a nitrogen-protected flask. Then add 2 g (1 mmol, 2 mmol amino) of polyetheramine dissolved in 10 mL of dichloromethane dropwise to the flask. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the first mixed solution with isocyanate group end groups.

[0074] 2. Dissolve 124.2 mg (0.5 mmol, 1.0 mmol amino) 4,4′-diaminodiphenyl disulfide in 10 mL of dichloromethane. Under a nitrogen atmosphere and with stirring at room temperature, add the dichloromethane solution of 4,4′-diaminodiphenyl disulfide to the first mixed solution obtained in step 1 dropwise. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the second mixed solution.

[0075] 3. Dissolve 198.3 mg (1.0 mmol, 2.0 mmol phenylamino group) of 4,4′-diaminodiphenylmethane in 10 mL of dichloromethane. Under the protection of nitrogen atmosphere and stirring at room temperature, add the second mixed solution obtained in step 2 dropwise to the dichloromethane solution of 4,4′-diaminodiphenylmethane. After the addition is complete, continue stirring for 8 h to ensure that the reaction is complete, and obtain the third mixed solution with phenylamino group at the end.

[0076] 4. Dissolve 54.0 mg (0.33 mmol, 1.0 mmol benzaldehyde group) of trimesin in 10 mL of dichloromethane. While stirring at room temperature, add the trimesin dichloromethane solution dropwise to the third mixed solution obtained in step 3. After the addition is complete, continue stirring for 48 h to allow the reaction to proceed fully, and obtain the fourth mixed solution.

[0077] 5. The fourth mixed solution described in step 4 is poured into a glass petri dish. After the solvent evaporates at room temperature with a humidity of 20% to 35%, it is then vacuum dried at 50-80°C for 48 hours to obtain the polymer material containing aromatic Schiff base bonds, named Sample 3, with a thickness of approximately 420 μm.

[0078] In Example 3, the molar fraction of aromatic Schiff base bonds was 100 mol%.

[0079] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 3, the polymer material has high visible light transmittance.

[0080] The polymer material obtained in Example 3 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 As shown in sample 3. Sample 3 has a transmittance of 88.9% at a visible light wavelength of 550 nm and an ultraviolet blocking rate of 100% in the entire ultraviolet region.

[0081] Example 4

[0082] 1. Add 444.5 mg (2 mmol, 4 mmol isocyanate group) of isophorone diisocyanate dissolved in 20 mL of dichloromethane to a nitrogen-protected flask. Then add 2 g (1 mmol, 2 mmol amino) of polyetheramine dissolved in 10 mL of dichloromethane dropwise to the flask. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the first mixed solution with isocyanate group end groups.

[0083] 2. Dissolve 186.3 mg (0.75 mmol, 1.5 mmol amino) 4,4′-diaminodiphenyl disulfide in 10 mL of dichloromethane. Under a nitrogen atmosphere and with stirring at room temperature, add the dichloromethane solution of 4,4′-diaminodiphenyl disulfide dropwise to the first mixed solution obtained in step 1. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the second mixed solution.

[0084] 3. Dissolve 99.1 mg (0.5 mmol, 1.0 mmol phenylamino group) of 4,4′-diaminodiphenylmethane in 10 mL of dichloromethane. Under a nitrogen atmosphere and with stirring at room temperature, add the second mixed solution obtained in step 2 dropwise to the dichloromethane solution of 4,4′-diaminodiphenylmethane. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the third mixed solution with phenylamino group at the end.

[0085] 4. Dissolve 27.0 mg (0.167 mmol, 0.5 mmol benzaldehyde group) of trimesin in 10 mL of dichloromethane. While stirring at room temperature, add the trimesin dichloromethane solution dropwise to the third mixed solution obtained in step 3. After the addition is complete, continue stirring for 48 h to allow the reaction to proceed fully, and obtain the fourth mixed solution.

[0086] 5. The fourth mixed solution described in step 4 is poured into a glass petri dish. After the solvent evaporates at room temperature with a humidity of 20% to 35%, it is then vacuum dried at 50-80°C for 48 hours to obtain the polymer material containing aromatic Schiff base bonds, named Sample 4, with a thickness of approximately 420 μm.

[0087] In Example 4, the molar fraction of aromatic Schiff base bonds was 50 mol%.

[0088] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 4, the polymer material has high visible light transmittance.

[0089] The polymer material obtained in Example 4 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 As shown in sample 4. Sample 4 has a transmittance of 87.4% at a visible wavelength of 550 nm and an ultraviolet blocking rate of 100% in the entire ultraviolet region.

[0090] By comparing the transmittance and UV blocking rate of the polymer materials (samples 1, 2, 3, and 4) obtained in Examples 1, 2, 3, and 4 at a visible wavelength of 550 nm, it can be inferred that within the range of the molar fraction of aromatic Schiff base bonds presented in the examples, the visible light transmittance and UV blocking properties of the polymer materials are not significantly dependent on the molar fraction of aromatic Schiff base bonds.

[0091] Example 5

[0092] 1. Add 444.5 mg (2 mmol, 4 mmol isocyanate group) of isophorone diisocyanate dissolved in 20 mL of dichloromethane to a nitrogen-protected flask. Then add 2 g (1 mmol, 2 mmol amino) of polyetheramine dissolved in 10 mL of dichloromethane dropwise to the flask. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the first mixed solution with isocyanate group end groups.

[0093] 2. Dissolve 124.2 mg (0.5 mmol, 1.0 mmol amino) 4,4′-diaminodiphenyl disulfide in 10 mL of dichloromethane. Under a nitrogen atmosphere and with stirring at room temperature, add the dichloromethane solution of 4,4′-diaminodiphenyl disulfide to the first mixed solution obtained in step 1 dropwise. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the second mixed solution.

[0094] 3. Dissolve 198.3 mg (1.0 mmol, 2.0 mmol phenylamino group) of 4,4′-diaminodiphenylmethane in 10 mL of dichloromethane. Under the protection of nitrogen atmosphere and stirring at room temperature, add the second mixed solution obtained in step 2 dropwise to the dichloromethane solution of 4,4′-diaminodiphenylmethane. After the addition is complete, continue stirring for 8 h to ensure that the reaction is complete, and obtain the third mixed solution with phenylamino group at the end.

[0095] 4. Dissolve 120.2 mg (1.0 mmol, 1.0 mmol benzaldehyde group) of p-methylbenzaldehyde in 10 mL of dichloromethane. While stirring at room temperature, add the dichloromethane solution of p-methylbenzaldehyde dropwise to the second mixed solution obtained in step 2. After the addition is complete, continue stirring for 24 h to allow the reaction to proceed fully, and obtain the fourth mixed solution.

[0096] 5. The fourth mixed solution described in step 3 is poured into a glass petri dish. After the solvent evaporates at room temperature, it is then vacuum dried at 50-80℃ for 48 hours to obtain the polymer material containing aromatic Schiff base bonds, named Sample 5, with a thickness of approximately 400 μm.

[0097] In Example 5, the molar fraction of aromatic Schiff base bonds was 100 mol%.

[0098] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 5, the polymer material exhibits high transmittance of visible light.

[0099] The polymer material obtained in Example 5 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 As shown in sample 5. Sample 5 has a transmittance of 88.7% at a visible light wavelength of 550 nm and an ultraviolet blocking rate of 100% in the entire ultraviolet region.

[0100] Example 6

[0101] The polymer material was prepared according to the method of Example 3, except that the amount of trimesaldehyde added was changed to 0 mg. The obtained sample was named Sample 6, with a thickness of approximately 400 μm.

[0102] In Example 6, the molar fraction of aromatic Schiff base bonds was 0 mol%.

[0103] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 6, the polymer material exhibits high visible light transmittance.

[0104] The polymer material obtained in Example 6 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 Sample 6 is shown in the figure. Sample 6 has a transmittance of 92% at a visible light wavelength of 550 nm and an ultraviolet blocking rate of 75.6% in the entire ultraviolet region.

[0105] Example 7

[0106] 1. Add 444.5 mg (2 mmol, 4 mmol isocyanate group) of isophorone diisocyanate dissolved in 20 mL of dichloromethane to a nitrogen-protected flask. Then add 2 g (1 mmol, 2 mmol amino) of polyetheramine dissolved in 10 mL of dichloromethane dropwise to the flask. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the first mixed solution with isocyanate group end groups.

[0107] 2. Dissolve 124.2 mg (0.5 mmol, 1.0 mmol amino) 4,4′-diaminodiphenyl disulfide in 10 mL of dichloromethane. Under a nitrogen atmosphere and with stirring at room temperature, add the dichloromethane solution of 4,4′-diaminodiphenyl disulfide to the first mixed solution obtained in step 1 dropwise. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the second mixed solution.

[0108] 3. Dissolve 88.1 mg (1.0 mmol, 2.0 mmol amino) 1,4-butanediamine in 25 mL of dichloromethane. Under a nitrogen atmosphere and stirring at room temperature, add the second mixed solution obtained in step 2 dropwise to the dichloromethane solution of 1,4-butanediamine. After the addition is complete, continue stirring for 8 h to ensure the reaction is complete, and obtain the third mixed solution with amino end groups.

[0109] 4. Dissolve 54.0 mg (0.33 mmol, 1.0 mmol benzaldehyde group) of trimesin in 10 mL of dichloromethane. While stirring at room temperature, add the trimesin dichloromethane solution dropwise to the third mixed solution obtained in step 4. After the addition is complete, continue stirring for 48 h to allow the reaction to proceed fully, and obtain the fourth mixed solution.

[0110] 5. The fourth mixed solution described in step 4 is poured into a glass petri dish. After the solvent evaporates at room temperature with a humidity of 20% to 35%, it is then vacuum dried at 50-80°C for 48 hours to obtain the polymer material containing aromatic Schiff base bonds, named Sample 7, with a thickness of approximately 380 μm.

[0111] In Example 7, the molar fraction of aromatic Schiff base bonds was 0 mol%, and the molar fraction of non-aromatic Schiff base bonds was 100 mol%.

[0112] Repeating the method of this embodiment, the resulting polymer material has the following appearance morphology. Figure 1 As shown in sample 7, the polymer material exhibits high transmittance of visible light.

[0113] The polymer material obtained in Example 7 was subjected to ultraviolet-visible transmission spectroscopy, and the test results are as follows: Figure 2 As shown in sample 7, sample 7 has a transmittance of 92% at a visible light wavelength of 550 nm and an ultraviolet blocking rate of 98.8% in the entire ultraviolet region.

[0114] By comparing the transmittance at 550 nm visible light wavelength and the UV blocking rate in the full UV region of the polymer materials (samples 1, 2, 3, 4, and 5) obtained in Examples 1, 2, 3, 4, and 5 with the polymer materials (samples 6 and 7) obtained in Examples 6 and 7, it can be inferred that the aromatic Schiff base bonds with continuous conjugated structures in the polymer materials are a crucial factor for obtaining excellent UV blocking performance.

[0115] Example 8

[0116] Different volumes of the fourth mixed solution prepared in Example 1 were poured into glass petri dishes. After the solvent evaporated at room temperature with a humidity of 20%–35%, the samples were vacuum dried at 50–80°C for 48 hours to obtain the polymer material containing aromatic Schiff base bonds. Due to the different volumes of the fourth mixed solution, the thickness of the dried polymer material varied, ranging from 50 to 420 μm. The polymer material with a thickness of 50 μm was named Sample 8-1, the polymer material with a thickness of 60 μm was named Sample 8-2, the polymer material with a thickness of 90 μm was named Sample 8-3, the polymer material with a thickness of 110 μm was named Sample 8-4, the polymer material with a thickness of 130 μm was named Sample 8-5, the polymer material with a thickness of 140 μm was named Sample 8-6, and the polymer material with a thickness of 160 μm was named Sample 8-7.

[0117] Repeating the method of this embodiment, the morphologies of several polymer materials of different thicknesses are as follows: Figure 3 As shown in the diagram, based on the appearance morphology images, all of the polymer materials exhibit high visible light transmittance, indicating that the transparency of polymer materials is not significantly dependent on thickness.

[0118] The polymer materials of different thicknesses obtained in Example 8 were subjected to ultraviolet-visible transmission spectroscopy measurements, and the test results are as follows: Figure 4 As shown in the figure. The test results show that the thickness has little effect on the transmittance of the polymer material at a visible light wavelength of 550 nm, with no obvious regularity. The UV blocking rate in the entire UV region increases with the increase of the polymer material thickness, and when the thickness of the polymer material reaches more than 140 μm, the UV blocking rate in the entire UV region reaches 100%.

[0119] Example 9

[0120] The optical stability of the polymer material under prolonged high temperature: The polymer material obtained in Example 1 was continuously placed in a 65°C oven, and the optical properties (visible light transmittance and full ultraviolet blocking performance) of the polymer material were measured at different times. The test results are as follows: Figure 5As shown, after being placed at 65°C for 240 hours, the polymer material exhibits a transmittance of 90% at a visible light wavelength of 550 nm, which is comparable to the transmittance (90.5%) of the untreated sample; the blocking rate in the entire ultraviolet region remains 100%. The test results demonstrate that the polymer material maintains excellent visible light transmittance and ultraviolet blocking properties even under prolonged high temperatures.

[0121] The optical stability of the polymer material under long-term ultraviolet irradiation: The polymer material obtained in Example 1 was continuously irradiated with ultraviolet light at a wavelength of 340 nm, and the optical properties (visible light transmittance and full ultraviolet blocking performance) of the polymer material under irradiation for different times were measured. The test results are as follows: Figure 6 As shown, after being placed under ultraviolet light at a wavelength of 340 nm for 240 hours, the polymer material exhibits a transmittance of 81.2% at a visible light wavelength of 550 nm, while maintaining a 100% blocking rate in the entire ultraviolet region. The test results demonstrate that the polymer material can maintain excellent visible light transmittance and full ultraviolet blocking properties even under prolonged ultraviolet irradiation.

[0122] Example 10

[0123] The self-healing function of samples 1, 2, 3, and 4 obtained in Examples 1, 2, 3, and 4 (the four samples were formed into films at room temperature, then vacuum dried at 50-80°C for 48 hours to remove residual solvent, and no other treatment was performed afterwards) was determined using N,N-dimethylformamide and dimethyl sulfoxide as solvents. The study found that, with the assistance of N,N-dimethylformamide, all four samples could complete self-healing within 3-10 minutes. Micrographs are shown below. Figure 7 As shown in the image. In comparison, although all four samples could also complete self-healing with the assistance of dimethyl sulfoxide, it took longer (3-6 hours), as shown in the micrographs. Figure 8 As shown.

[0124] Example 11

[0125] The polymer material with a thickness of 140 μm from Example 8 was selected for this application demonstration. The selected polymer material was directly attached to a pure glass slide or an eyeglass lens to obtain polymer material-glass slide composite and polymer material-eyeglass lens composite, respectively.

[0126] Repeating the method of this embodiment, the resulting polymer material-eyeglass lens composite (sample 11-1) exhibits the following visible light transmittance and ultraviolet blocking properties: Figure 9 As shown. Figure 9The left lens (sample 11-1, a glass lens with a 140μm polymer material adhered to it) served as the experimental group, while the right lens (a glass lens without the polymer material) served as the control group. Under natural light, both lenses exhibited high visible light transmittance. Under ultraviolet light, because the polymer film on the left lens blocked ultraviolet light, no blue fluorescence was observed in the left cornea. In contrast, because the right lens could not completely block ultraviolet light, blue fluorescence was observed in the right cornea (both corneas were coated with a fluorescent dye that appeared blue under ultraviolet light).

[0127] The polymer-glass composite and the pure glass slide in Example 11 were subjected to ultraviolet-visible transmission spectroscopy measurements, and the test results are as follows: Figure 10 Sample 11-2 and a pure glass slide are shown. Test results show that the transmittance of sample 11-2 and the pure glass slide at a visible wavelength of 550 nm are 91.7% and 92.4%, respectively, and the UV blocking rates in the full UV region are 100% and 56.6%, respectively. These results indicate that the polymer material exhibits significant application advantages in transparent, high-efficiency UV-blocking ultra-thin films. The high UV blocking performance of the polymer material originates from the continuous conjugated structure of aromatic Schiff base bonds. To verify this hypothesis, this application measured the UV-Vis absorption spectra of model small molecules (trifunctional and bifunctional) containing aromatic Schiff base bonds, as shown below. Figure 11 and 12 As shown in the figure. The measurement results show that the model small molecule has strong absorption in the entire ultraviolet region (200-400 nm), which endows the polymer material with excellent ultraviolet blocking properties.

[0128] Example 12

[0129] Two commercially available 3M transparent UV-blocking automotive films (windshields) were used to prepare comparative samples. The commercially available 3M transparent UV-blocking automotive films were directly applied to a pure glass sheet to prepare 3M film-glass composites, which were named Sample 12-1 and Sample 12-2. The thickness of the 3M film in Sample 12-1 was 59±2 μm, and the thickness of the 3M film in Sample 12-2 was 46±3 μm.

[0130] The morphology of the obtained 3M film-glass composite is as follows: Figure 13 As shown in samples 12-1 and 12-2, the 3M film-glass composite exhibits visible light transmittance.

[0131] The 3M film-glass composite obtained in Example 12 was subjected to UV-Vis transmission spectroscopy, and the test results are as follows: Figure 14Samples 12-1 and 12-2 are shown in the figure. The transmittance of samples 12-1 and 12-2 at a visible light wavelength of 550 nm is 91% and 85.3%, respectively, and the ultraviolet blocking efficiencies in the full ultraviolet region are 97.6% and 98.5%, respectively.

[0132] By comparing the transmittance at 550 nm visible light wavelength and the UV blocking rate in the entire UV region of the polymer material-glass composite obtained in Example 11 (sample 11-2), the 3M film-glass composite obtained in Example 12 (samples 12-1 and 12-2), and pure glass, it can be inferred that the transmittance of the polymer material at 550 nm visible light wavelength is comparable to that of pure glass, and it possesses excellent UV blocking performance in the entire UV region. Furthermore, compared to commercially available transparent UV-protective automotive films, the polymer material better combines high visible light transmittance with high UV protection performance, showing broad application prospects in the field of transparent UV-protective films / coatings.

[0133] The optical performance data of the samples in the examples are compared with existing technologies and commercial products. For ease of comparison, the present invention is described as follows: The entire ultraviolet spectrum is divided into the UVC region (wavelength range of 200-280nm), the UVB region (wavelength range of 280-320nm), and the UVA region (wavelength range of 320-400nm). The present invention selects 254nm wavelength as the representative wavelength of the UVC region, 300nm wavelength as the representative wavelength of the UVB region, and 380nm and 400nm wavelengths as the representative wavelengths of the UVA region. The wavelength range of the visible light region is 400-800nm, and the present invention selects 550nm wavelength as the representative wavelength of the visible light region. Therefore, the following parameters are defined as follows: T 254 T represents the transmittance of the polymer material at a 254 nm ultraviolet light wavelength. 300 T represents the transmittance of the polymer material at a 300 nm ultraviolet light wavelength. 380 T represents the transmittance of the polymer material at a 380 nm ultraviolet light wavelength. 400 T represents the transmittance of the polymer material at a 400 nm ultraviolet light wavelength. 550 Represents the transmittance of the polymer material at a visible light wavelength of 550 nm, 100%-T 254 Represents the UV blocking efficiency of the polymer material at a UV wavelength of 254 nm, 100%-T 300 Represents the UV blocking efficiency of the polymer material at a UV wavelength of 300 nm, 100%-T 380 Represents the UV blocking efficiency of the polymer material at a UV wavelength of 380 nm, 100%-T 400 This represents the ultraviolet blocking efficiency of the polymer material at a wavelength of 400 nm.

[0134] First, the optical properties of samples 1, 2, 3, and 4 in Examples 1, 2, 3, and 4 are compared with those in the prior art. The following data (1) are the optical performance data of the samples in the examples, and (2)-(22) are the optical performance data of the prior art. (1) Sample 1: 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 91%; Sample 2: 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 It was 87.7%; Sample 3: 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 The percentage was 88.9%; Sample 4: 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 is 87.4%; (2) Nacre-inspired polyglutamic acid / layered double hydroxide bionanocompositefilm with high mechanical, translucence and UV-blocking properties, Ben-LiangLiang and Peng-Gang Yin*, 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 98%, 100%-T 400 90%, T 550is 50%; (3) Direct synthesis of carbon quantum dots in aqueous polymer solution: One-pot reaction and preparation of transparent UV-blocking films, Samuel C. Hess and Wendelin J. Stark*, 100%-T 254 is 100%, 100%-T 300 is 92%, 100%-T 380 is 100%, 100%-T 400 is 98%, T 550 is 72%; (4) Biomimetic supertough and strong biodegradable polymeric materials with improved thermal properties and excellent UV-blocking performance, Xiao Zhang and Xueqing Qiu*, 100%-T 254 is 100%, 100%-T 300 is 99.5% / 100%, 100%-T 380 is 79% / 100%, 100%-T 400 is 71% / 100%, T 550 is 70% / 10%; (5) UV-blocking synthetic biopolymer from biomass-based bifurandiester and ethylene glycol, Tuomo P. Kainulainen and P. Heiskanen*, 100%-T 254 is 100%, 100%-T 300 is 100%, 100%-T 380 is 100%, 100%-T 400 is 96%, T 550 is 72%; (6) Thin biobased transparent UV-blocking coating enabled by nanoparticle self-assembly, Emily Olson and Shan Jiang*, 100%-T 254 is 100%, 100%-T 300100%, 100%-T 380 85%, 100%-T 400 83%, T 550 is 55%; (7) Biodegradable UV-blocking films through core-shell lignin-melanin nanoparticles in poly(butylene adipate-co-terephthalate), Qianqiu Xing and Wen-Jun Wang*, 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 91%, 100%-T 400 88%, T 550 30%; (8) Hydrogen-bonding assembly of heteropolyacid and poly(vinyl alcohol) for strong, flexible, and transparent UV-protective films, Ziang Zhang and Zhiming Zou*, 100%-T 254 92%, 100%-T 300 94%, 100%-T 380 42%, 100%-T 400 It is 34%, T 550 95%; (9) Dual roles of a transparent polymer film containing dispersed N-doped carbon dots: Ahigh-efficiency bluelight converter and UV screen, Barun Kumar Barman and Karuna Kar Nanda*, 100%-T 254 100%, 100%-T 300 82%, 100%-T 380 100%, 100%-T 400 It is 82%, T 550is 76%; (10) Renewable dynamic covalent network based on itaconic anhydride crosslinked polyglycerol: Adaptability, UV blocking and fluorescence, Yinfa Shan and Jinwen Zhang*, 100%-T 254 is 100% / 100%, 100%-T 300 is 100% / 100%, 100%-T 380 is 100% / 98%, 100%-T 400 is 100% / 95%, T 550 is 41% / 65%; (11) Very strong, super-tough, antibacterial, and biodegradable polymeric materials with excellent UV-blocking performance, Xiao Zhang and Xueqing Qiu*, 100%-T 254 is 100%, 100%-T 300 is 100% / 98%, 100%-T 380 is 100% / 67%, 100%-T 400 is 100% / 65%, T 550 is 3% / 68%; (12) Biomimetic soy protein-based exterior-use films with excellent UV-blocking performance from catechol derivative acacia mangium tannin, Liuliu Wang and Wei Zhang*, 100%-T 254 is 100%, 100%-T 300 is 100%, 100%-T 380 is 100%, 100%-T 400 is 99.5%, T 550 is 34%; (13) Lignin-based direct ink printed structural scaffolds, Bo Jiang and Liangbin Hu*, 100%-T 254 is 100%, 100%-T 300100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 is 0%; (14) UV-resistant transparent lignin-basedpolyurethane elastomer with repeatable processing performance, Xinxiang Li andChaoxia Wang*, 100%-T 254 93%, 100%-T 300 94%, 100%-T 380 95%, 100%-T 400 95%, T 550 17%; (15) Amolecularly engineered bioderived polyphosphate forenhanced flame retardant, UV-blocking and mechanical properties of poly(lacticacid), Yan Zhang and Pingan Song*, 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100% / 94%, T 550 is 5.5% / 48.3%; (16) Facile fabrication oftough, strong, and biodegradable soy protein-based composite films with excellent UV-blocking performance, Jiongjiong Li and Jianzhang Li*, 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 It is 98.6% / 100%, T 550is 63% / 40%; (17) Preparation of thermostable and compatible citrate-based polyesters for enhancing the ultraviolet shielding performance of thermoplastic resin, Heng Chen and Hao Yuan*, 100%-T 254 is 100%, 100%-T 300 is 100%, 100%-T 380 is 100%, 100%-T 400 is 99.5%, T 550 is 81%; (18) One-step synthesis of lignin-based triblock copolymers as high-temperature and UV-blocking thermoplastic elastomer, Yi Wan and Yuetao Zhang*, 100%-T 254 is 100%, 100%-T 300 is 100%, 100%-T 380 is 10%, 100%-T 400 is 8%, T 550 is 94%; (19) UV resistance, anticorrosion and high toughness bio-based waterborne polyurethane enabled by a sorbitan monooleate, Henghui Deng and Chaoqun Zhang*, 100%-T 254 is 100%, 100%-T 300 is 100%, 100%-T 380 is 97%, 100%-T 400 is 95%, T 550 is 82%; (20) Green fabrication of high strength, transparent cellulose-based films with durable fluorescence and UV-blocking performance, Fang Peng and Haisong Qi*, 100%-T 254100%, 100%-T 300 100%, 100%-T 380 99.5%, 100%-T 400 70%, T 550 is 88%; (21) Inverse vulcanization of elemental sulfur with naturalrosin to prepare high sulfur content polymers with excellent solubility and UV-blocking performance, Jinhui Qiu and Li Zhou*, 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 51%, 100%-T 400 It is 42%, T 550 is 89%; (22) Facile fabrication of apolyvinyl alcohol-based hydrophobic fluorescent film via the Hantzschreaction for broadband UV protection, Hongchen Liu and Haisong Qi*, 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 The figure is 90%. See the detailed comparison results below. Figure 15 In the figure, the numbers after ref represent prior art numbers. As can be seen from the results, the polymer material of the present invention, compared with the prior art, can achieve both high visible light transmittance (transmittance of more than 87% at a visible light wavelength of 550nm, preferably greater than 90%) and ultraviolet blocking performance in the entire ultraviolet region (ultraviolet blocking rate of 100% at different representative wavelengths in the 200-400nm ultraviolet region).

[0135] Furthermore, the polymer material described in this invention can be used as a transparent UV-protective film / coating. Therefore, the optical properties of sample 11-1 in Example 11 are compared with those of existing commercial 3M transparent UV-protective automotive films. Below (23) is the polymer material described in this invention, and (24) is a commercial 3M transparent UV-protective automotive film. (23) Sample 11-1: 100%-T254 100%, 100%-T 300 100%, 100%-T 380 100%, 100%-T 400 For 100%, T 550 The percentage was 91.7%; Sample 12-1: 100%-T 254 100%, 100%-T 300 99.9%, 100%-T 380 99.6%, 100%-T 400 It was 50.9%, T 550 91%; Sample 12-2: 100%-T 254 100%, 100%-T 300 100%, 100%-T 380 97.9%, 100%-T 400 It is 42.4%, T 550 The figure is 85.3%. See the detailed comparison results below. Figure 16 The results show that, compared with commercially available 3M transparent UV-blocking automotive film, the polymer material described in this invention can better balance high visible light transmittance and full UV light blocking.

Claims

1. A self-healing polymer material that combines high visible light transmittance and full ultraviolet light blocking properties, characterized in that, The polymer material contains aromatic Schiff base bonds. The aromatic Schiff base bond is formed by the reaction of the phenylamino group in the polymer containing the phenylamino group and the benzaldehyde group in the compound containing the benzaldehyde group; the structure of the polymer containing the phenylamino group is as follows: R1 is R2 is R3 is R5 is H, F, Cl, Br, I, CN, CH3, CF3, OCH3, OCF3, COOH or OH, and R6 and R7 are saturated alkyl groups with 1 to 6 carbon atoms, m = 6 to 60, n = 1 to 5, p = 1 to 3, q ​​= 2 to 20, and r = 1 to 3.

2. The self-healing polymer material according to claim 1, characterized in that, The polymer material has high visible light transmittance, that is, the transmittance reaches more than 87% at a visible light wavelength of 550nm; the polymer material also has full ultraviolet light blocking properties, that is, the ultraviolet blocking rate in the 200-400nm ultraviolet region reaches 100%.

3. The self-healing polymer material according to claim 1, characterized in that, The molar fraction of aromatic Schiff base bonds in the polymer material is greater than 5 mol%.

4. The self-healing polymer material according to any one of claims 1 to 3, characterized in that, The aromatic Schiff base bond is located at any one or more positions in the polymer network crosslinking site, polymer backbone, polymer branched chain, and polymer side chain.

5. The self-healing polymer material according to claim 1, characterized in that, The polymer material has a solvent-assisted room temperature self-healing function, and the solvent is selected from any one of N,N-dimethylformamide and dimethyl sulfoxide.

6. The self-healing polymer material according to claim 1, characterized in that, The structures of compounds containing benzaldehyde groups are as follows: R8 can be H, F, Cl, Br, I, CN, CH3, CF3, OCH3, OCF3, COOH, or OH, and A can be CH or N.

7. The method for preparing the self-healing polymer material according to any one of claims 1 to 6, characterized in that, Includes the following steps: A solution of a compound containing a benzaldehyde group is added dropwise to a polymer solution containing a phenylamino group. The reaction is stirred until complete, so that the molar ratio of aldehyde group to phenylamino group is 1:

1. The solution after complete reaction is cast and the solvent is evaporated. After drying, the polymer material is obtained.

8. The method for preparing the self-healing polymer material according to claim 7, characterized in that, In the preparation process, the solvent used for the compound solution containing benzaldehyde group and the polymer solution containing phenylamino group is any one or more of dichloromethane, dichloroethane, trichloromethane, tetrahydrofuran, toluene, N,N-dimethylformamide, and dimethyl sulfoxide.

9. The use of the self-healing polymer material according to any one of claims 1-6, characterized in that, The polymer material is used to prepare transparent UV-resistant films / coatings, transparent packaging materials, greenhouse films, and high-efficiency UV-resistant solar cell encapsulation films.

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