Transparent polymer film with adjustable refractive index and manufacturing method and application thereof

Abstract

The invention discloses a transparent polymer film with an adjustable refractive index and a manufacturing method and application thereof, and belongs to the technical field of functional film materials. The transparent polymer film with the adjustable refractive index comprises a compound I with the following structure (1) and a compound II with the following structure (2), wherein the compound II is formed by crosslinking the compound I through ultraviolet light, and the compound II is # imgabs0 #, wherein n is the number of repeated structural units; r1 is any one of H, a halogen atom, a fluorine-containing methyl group, a C1-20 alkyl group, a C1-20 alkoxy group and an allyloxy group. The transparent polymer film provided by the invention has the characteristics of high refractive index, refractive index adjustability, wide use temperature range, low dielectric constant, low dielectric loss and no absorption at a 850nm optical communication wave band, and is simple to prepare, low in cost and suitable for the field of high-integration optical communication.

Description

Technical Field

[0001] The present application belongs to the technical field of optical film materials, and in particular relates to a transparent polymer film with adjustable refractive index, a manufacturing method thereof, and an application thereof. Background Art

[0002] Polymer optical waveguide materials have the advantages of high optical transparency, easy integration, high refractive index and easy tunability, making them one of the most promising optical materials for preparing low-cost, high-performance photonic devices. However, traditional polymer optical waveguide materials are mostly thermoplastic materials, which generally have the defect of difficult refractive index adjustment, limiting their application in optical communications. Therefore, it is necessary to design and manufacture polymer optical waveguide materials with high refractive index and easy tunability.

[0003] The patent application with publication number CN 110643041 A discloses a colorless and transparent polyimide film with adjustable refractive index. It utilizes an improved nano-composite technology of nano zinc oxide with zinc carbonate coated on the surface of a polyimide matrix composite, so that the prepared film has excellent mechanical properties, thermal properties, and insulation properties, while also giving it tunable refractive index.

[0004] However, the preparation of the nanocomposite technology mentioned above is complicated, costly, and difficult to mass-produce; moreover, its refractive index depends on the specific parameters of the nano zinc oxide with zinc carbonate coated on the surface, and it does not have in-situ refractive index adjustability, which limits its application in highly integrated optical communications. Summary of the invention

[0005] The present application discloses a transparent polymer film with adjustable refractive index, and a manufacturing method and application thereof, which are used to solve the technical problems of the above-mentioned nanocomposite technology that the preparation is complicated and costly, and the obtained film material does not have in-situ refractive index adjustability.

[0006] In order to achieve the above objectives, the technical solution adopted in this application is:

[0007] In a first aspect, the present application discloses a transparent polymer film with adjustable refractive index, wherein the material composition of the transparent polymer film comprises:

[0008] (a) a compound I of structure (1); and,

[0009] (b) Compound I is cross-linked by ultraviolet light to form compound II of structure (2);

[0010]

[0011] Where n is the number of structural units; R1 is H, halogen atom, fluorinated methyl, C 1-20 Alkyl, C 1-20 Any of an alkoxy group and an allyloxy group.

[0012] According to the disclosure of the first aspect of the present application, the material composition of the transparent polymer film with adjustable refractive index consists of compound I and compound II;

[0013] The molar content of compound II is 2.64-83% of the total of compound I and compound II.

[0014] According to the disclosure of the first aspect of the present application, the material composition of the transparent polymer film with adjustable refractive index consists of compound I and compound II;

[0015] The molar content of compound II is 38-69% of the total of compound I and compound II.

[0016] According to the disclosure of the first aspect of the present application, the compound I described in the present application comprises:

[0017]

[0018] In a second aspect, the present application also discloses a method for manufacturing the transparent polymer film with adjustable refractive index as described above, which comprises:

[0019] The hydroxyethyl methacrylate and 4-(R1) cinnamic acid are subjected to an esterification reaction to synthesize [4-(R1) cinnamic acid] hydroxyethyl methacrylate;

[0020] The [4-(R1) cinnamic acid] hydroxyethyl methacrylate is dissolved in a solvent system containing a catalyst to perform a free radical polymerization reaction to synthesize compound I;

[0021] After coating the solvent in which compound I is dissolved, ultraviolet light crosslinking and thermal curing are sequentially performed to obtain the product.

[0022] According to the disclosure of the second aspect of the present application, the solvent is one of N,N-dimethylformamide, propylene glycol methyl ether acetate, and dimethyl sulfoxide.

[0023] According to the disclosure of the second aspect of the present application, the mass concentration of the dissolved [4-(R1)cinnamic acid]hydroxyethyl methacrylate is 0.01-1.0 mol / L.

[0024] According to the disclosure of the second aspect of the present application, the molar ratio of the [4-(R1) cinnamic acid] hydroxyethyl methacrylate solution to the catalyst is 100-500:1.

[0025] According to the disclosure of the second aspect of the present application, the mass concentration of Compound I in the solvent is 3-5wt%.

[0026] According to the disclosure of the second aspect of the present application, when the ultraviolet light crosslinking is performed, the wavelength of the ultraviolet light is 200-380nm and the time is 10-600s;

[0027] According to the disclosure of the second aspect of the present application, the thermal curing temperature is 100-110° C. and the time is 15-60 min.

[0028] In a third aspect, the present application also discloses the use of the transparent polymer film with adjustable refractive index described in the above application in materials including optical waveguides and microelectronic materials.

[0029] Compared with the prior art, the advantages or beneficial effects of the present application include at least:

[0030] The transparent polymer film with adjustable refractive index provided by the present application is a combination of compound I with structure (1) and compound II with intermolecular crosslinking structure (2) generated by crosslinking compound I under ultraviolet light. On the one hand, the crosslinking density and electron cloud density of the intramolecular crosslinking structure of compound I can be improved, and the electronic polarization rate of the crosslinking region can be effectively promoted, so that the refractive index of the crosslinking region is improved, thereby increasing the refractive index contrast with the non-crosslinking region. At the same time, the intramolecular crosslinking structure of compound I also has the ability to generate compound II with intermolecular crosslinking structure initiated by ultraviolet light, and the intermolecular crosslinking degree is positively correlated with the ultraviolet irradiation time, which can give the prepared optical film the adjustability of the refractive index under ultraviolet light; on the other hand, the thermal decomposition temperature of the intramolecular crosslinking structure of compound I can be increased. degree, so that the prepared optical film has a wide operating temperature range; thirdly, compound II is the intermolecular cross-linking structure of compound I, which can effectively eliminate the internal reflection of the intermolecular cross-linking structure of different monomers, and the conversion of compound I to compound II can effectively destroy the conjugated structure, weaken electron delocalization, and improve the ultraviolet-visible light transmittance; fourthly, compound II can inhibit the segment movement of the intramolecular cross-linking structure of compound I, reduce the free volume and inhibit dipole polarization, so that the prepared optical film has a low dielectric constant and low dielectric loss; fifthly, the optical film has no absorption at the 850nm optical communication band, can be used in the field of optical fiber communication, and has a single structural unit, omitting the modification process of the doping molecule, simple preparation, low cost, and suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 The H NMR spectrum of the compound PMETPA provided in the examples of the present application;

[0033] Figure 2The gel permeation chromatogram of the compound PMETPA provided in the examples of the present application;

[0034] Figure 3 Thermogravimetric curve of the transparent polymer film with adjustable refractive index provided in the embodiment of the present application;

[0035] Figure 4 The ultraviolet-visible absorption spectrum of the transparent polymer film with adjustable refractive index provided in the embodiment of the present application;

[0036] Figure 5 A broadband dielectric spectrum of a transparent polymer film with adjustable refractive index provided in an embodiment of the present application;

[0037] Figure 6 The refractive index test results of the transparent polymer film with adjustable refractive index provided in the embodiments of the present application;

[0038] Figure 7 The transmittance test results of the transparent polymer film with adjustable refractive index provided in the embodiments of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments described in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0040] In the following description of this specification, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. Among them, A and B can be singular or plural; the symbol " / " means "or".

[0041] In the following description of this specification, the term "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of A, B or C", or "at least one of A, B and C" can mean any one of A, B, C, or A+B, or A+C, or B+C, or A+B+C, where A, B, C can be single or multiple, respectively.

[0042] In the following description of this specification, the order of serial numbers does not mean the order of execution. Some or all of the steps can be executed in parallel or one after the other. The execution order of each process should be determined by its function and internal logic, and does not constitute any limitation on the execution process of this embodiment.

[0043] In the following description of this specification, the numerical range should be understood to also specifically disclose each intermediate value between the upper and lower limits of the range. Any stated value or intermediate value in the stated range and any other stated value or each smaller range between the intermediate values ​​in the range are also included in this embodiment, and the upper and lower limits of the smaller range can be independently included or excluded in the range.

[0044] Unless otherwise specified, the technical / scientific terms used in this specification have the meanings commonly understood by those of ordinary skill in the art. Although this specification only describes preferred materials and methods, any similar or equivalent methods and materials may also be used in specific embodiments or test cases. All documents mentioned in this specification are incorporated by reference to disclose and describe methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0045] In a first aspect, the embodiments of the present application provide a transparent polymer film with adjustable refractive index. The material composition of the transparent polymer film with adjustable refractive index described in the present application comprises:

[0046] (a) a compound I of structure (1); and,

[0047] (b) Compound I is cross-linked by ultraviolet light to form compound II of structure (2);

[0048]

[0049] In the structure, n is the number of structural units; R1 is H, halogen atom, fluorinated methyl, C 1-20 Alkyl, C 1-20 Any of alkoxy and allyloxy. 1-20 Alkyl refers to a chain alkyl group having 1 to 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, cyclopropane, etc.; C 1-20 The alkoxy group refers to a chain alkoxy group having 1 to 20 carbon atoms, for example, methoxy, ethoxy, propoxy and the like.

[0050] In the embodiment of the present application, a compound I having a structure (1) and a compound II having an intermolecular crosslinking structure (2) generated by crosslinking compound I under ultraviolet light are combined to form an intermolecular crosslinking structure of compound I in the intramolecular crosslinking structure of compound I. On the one hand, the crosslinking density and electron cloud density of the intramolecular crosslinking structure of compound I can be improved, and the electronic polarization rate of the crosslinking region can be effectively promoted, so that the refractive index of the crosslinking region is improved, thereby increasing the refractive index contrast with the non-crosslinking region. At the same time, the intramolecular crosslinking structure of compound I also has the ability to generate the intermolecular crosslinking structure of compound II by ultraviolet light initiation, and the intermolecular crosslinking degree is positively correlated with the ultraviolet irradiation time, which can give the prepared optical film the adjustability of the refractive index under ultraviolet light; on the other hand, the intramolecular crosslinking structure of compound I can be improved. The thermal decomposition temperature of the cross-linked structure enables the prepared optical film to have a wide operating temperature range; thirdly, compound II is the intermolecular cross-linked structure of compound I, which can effectively eliminate the internal reflection of the intermolecular cross-linked structure of different monomers, and the conversion of compound I to compound II can effectively destroy the conjugated structure, weaken electron delocalization, and improve the ultraviolet-visible light transmittance; fourthly, compound II can inhibit the segment movement of the intramolecular cross-linked structure of compound I, reduce the free volume and inhibit dipole polarization, so that the prepared optical film has a low dielectric constant and low dielectric loss; fifthly, the optical film has no absorption at the 850nm optical communication band, can be used in the field of optical fiber communication, and has a single monomer phase, omitting the modification process of the doped molecules, is simple to prepare, low cost, and suitable for large-scale production.

[0051] According to the disclosure of the present application, the material composition of the transparent polymer film with adjustable refractive index described in the present application is composed of compound I and compound II, wherein the molar content of compound II is 2.64-83% of the total of compound I and compound II, such as 2.64%, 9.78%, 19%, 38%, 69%, 71%, 76% and 83%, etc. Among them, 38-69% is preferred to ensure a good refractive index increase effect.

[0052] According to the disclosure of the present application, the compound I comprises:

[0053]

[0054] In a second aspect, the present application also provides a method for manufacturing the transparent polymer film with adjustable refractive index as described in the above application, wherein the steps preferably include:

[0055] Step 1: esterify hydroxyethyl methacrylate with 4-(R1) cinnamic acid to synthesize [4-(R1) cinnamic acid] hydroxyethyl methacrylate;

[0056]

[0057] Step 2: dissolving the [4-(R1) cinnamic acid] hydroxyethyl methacrylate in a solvent system containing a catalyst to perform a free radical polymerization reaction to synthesize compound I;

[0058]

[0059] Step 3: After coating the solvent containing the dissolved compound I, UV light crosslinking and thermal curing are sequentially performed to obtain a transparent polymer film with adjustable refractive index.

[0060]

[0061] It is understood by those skilled in the art that R1 in 4-(R1)cinnamic acid and [4-(R1)cinnamic acid]hydroxyethyl methacrylate is the R1 group in compound I and / or compound II of the present application, wherein 4-(R1)cinnamic acid can be cinnamic acid, 4-fluorocinnamic acid, 4-chlorocinnamic acid, 4-(trifluoromethyl)cinnamic acid, 4-(methyl ether)cinnamic acid, etc., which can be purchased from the market or synthesized by methods known in the art.

[0062] According to the disclosure of the present application, the mass concentration of the [4-(R1) cinnamic acid] hydroxyethyl methacrylate when dissolved is preferably 0.01-1.0 mol / L, such as 0.01 mol / L, 0.02 mol / L, 0.03 mol / L, 0.05 mol / L, 0.08 mol / L and 1.0 mol / L, etc.; the molar ratio of the [4-(R1) cinnamic acid] hydroxyethyl methacrylate dissolved to the catalyst is preferably 100-500:1, such as 100:1, 200:1, 300-500:1, 400-500:1 and 500:1, etc.

[0063] It should be noted that the present application does not limit the specific catalyst and solvent of the solvent system containing the catalyst, and those skilled in the art can reasonably select them. For example, in this paper, azobisisobutyronitrile is dissolved in N,N-dimethylformamide as a catalyst to form a solvent system containing the catalyst. At the same time, the present application does not limit the specific parameters of the free radical polymerization reaction, which can be reasonably selected according to the intrinsic characteristics of the structural group. For example, the reaction temperature is set to 55-75°C and the time is 4-12h.

[0064] It should be noted that the embodiments of the present application do not limit the post-treatment of the free radical polymerization reaction of the [4-(R1) cinnamic acid] hydroxyethyl methacrylate dissolved in a solvent system containing a catalyst. For example, after the reaction is terminated, post-treatments such as dilution, sedimentation, washing, and drying are performed in sequence.

[0065] According to the disclosure of the present application, the solvent for dissolving compound I is one of N,N-dimethylformamide, propylene glycol methyl ether acetate, and dimethyl sulfoxide. Among them, these solvents have a relatively high boiling point, which can effectively prevent the precipitation of polymers due to excessive volatilization of the solvent during the photocuring process, ensure sufficient intramolecular crosslinking of the cinnamic acid group, and help improve the flatness of the crosslinked structure cured film.

[0066] According to the disclosure of the present application, the mass concentration of the compound I in the solvent is 3-5wt%, such as 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt% or any one within the range. In particular, the present application embodiment controls the mass concentration of the compound I to ensure that the cinnamic acid groups undergo sufficient molecular cross-linking to form a cross-linked structure, while improving the flatness of the cross-linked structure cured into a film.

[0067] According to the disclosure of the present application, when UV cross-linking is performed, the wavelength of UV light is 200-380nm, for example, 365nm; the time is 10-600s, for example, 10s, 20s, 30s, 60s, 120s, 240s, 360s, 600s, etc., wherein the molar content of compound II is closely related to the UV cross-linking time, and the UV cross-linking time can be adjusted to effectively control the molar content of compound II; the temperature for thermal curing is 100-110°C, for example, 100°C, 105°C, 110°C, etc.; the time is 15-60min, for example, 15min, 30min, 45min, 60min, etc.

[0068] In the third aspect, the embodiments of the present application also provide the application of the transparent polymer film with adjustable refractive index described in the above application, specifically, the transparent polymer film with adjustable refractive index described in the present application is used as a functional material such as an optical waveguide and microelectronics. Among them, in view of the characteristics of the transparent polymer film with adjustable refractive index described in the present application, such as high refractive index and refractive index tunability, wide operating temperature range, excellent ultraviolet light transmittance, low dielectric constant and low dielectric loss, etc., after being used as a functional material such as an optical waveguide and microelectronics, it can be used to prepare high-performance polymer optical waveguides, thermo-optical switches, chips and other microelectronic devices.

[0069] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0070] Example 1

[0071] This embodiment provides a method for preparing a transparent polymer film with adjustable refractive index, which specifically comprises:

[0072] Step 1: After adding 4.32 g of 4-(trifluoromethyl)cinnamic acid, 2.72 g of hydroxyethyl methacrylate, 0.495 g of 4-dimethylaminopyridine, 4.60 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 100 mL of dichloromethane into a 250 mL round-bottom flask, the round-bottom flask was placed in an oil bath at 25° C. for reaction for 36 h. Subsequently, the reaction solution was subjected to rotary evaporation until dichloromethane was completely removed. The obtained white solid was then recrystallized from 100 mL of anhydrous ethanol and dried in an oven at 30° C. to obtain [4-(trifluoromethyl)cinnamic acid]hydroxyethyl methacrylate with a yield of 95%;

[0073] Step 2: After adding 1.26g (3.89mmol) [4-(trifluoromethyl)cinnamic acid] hydroxyethyl methacrylate into a 100mL reaction tube, 20mL of ultra-dry dichloromethane was added to dissolve, liquid nitrogen was frozen and replaced with nitrogen three times. After thawing, azobisisobutyronitrile (6.39mg, 0.039mmol) was added under nitrogen atmosphere, and free radical polymerization was carried out at 65°C for 6h. After the reaction was completed, it was cooled to room temperature, and the reaction solution was concentrated to 5mL, precipitated into 200mL of ethanol, and centrifuged to obtain compound PMETPA, which was washed with ethanol three times with a yield of 70%. The structure of compound PMETPA is:

[0074]

[0075] Step 3: Dissolve 60 mg of the compound PMETPA in 4.0 mL of N,N-dimethylformamide (solution concentration is 5 wt%), inject 0.3 g of the solution onto a silicon wafer, and then spin coat at 600 rpm for 20 seconds. Place it directly under a 365 nm UV lamp and expose it to UV for 60 seconds. Dry it on a 60 ° C hot stage for 2 hours to remove most of the N,N-dimethylformamide solution, then place it in a vacuum oven, heat it to 100 ° C, and continue vacuum drying for 30 minutes to obtain a transparent polymer film with adjustable refractive index and a thickness of 12 μm.

[0076] In order to illustrate the technical effect of the technical solution of the present application, the compound PMETPA and the transparent polymer film prepared in Example 1 are used as samples for performance testing, specifically:

[0077] 1. Structural Characterization

[0078] The compound PMETPA prepared in Example 1 was analyzed using a Bruker 400-Left NMR spectrometer. 1 HNMR nuclear magnetic resonance spectroscopy characterization, the results are Figure 1 As shown. Among them, Figure 1 This is the H NMR spectrum of compound PMETPA.

[0079] according to Figure 1 It can be seen that Example 1 successfully synthesized the compound PMETPA shown in the structure.

[0080] 2. Molecular weight determination

[0081] The compound PMETPA prepared in Example 1 was subjected to gel permeation chromatography (40°C, THF elution, flow rate 1.0 mL·min -1 , polystyrene standard solution calibration) characterization, the results are Figure 2 As shown. Among them, Figure 2 This is the gel permeation chromatogram of compound PMETPA.

[0082] according to Figure 2 It can be seen that the molecular weight of the compound PMETPA is 46.5 kg / mol, and the number of structural units n of the compound PMETPA is calculated to be 150.

[0083] 3. Heat resistance characterization

[0084] The transparent polymer film with adjustable refractive index prepared in Example 1 was subjected to thermogravimetric analysis (nitrogen flow, heating rate of 10°C·min -1 , temperature range is 0-100℃), the result is Figure 3 As shown. Among them, Figure 3 Thermogravimetric curve of transparent polymer film with tunable refractive index.

[0085] according to Figure 3 It can be seen that the thermal decomposition temperature of the transparent polymer film with adjustable refractive index is 274°C, and it has good thermal stability.

[0086] 4. Optical performance test

[0087] The ultraviolet absorption spectrum test of the transparent polymer film with adjustable refractive index prepared in Example 1 was performed, and the results were as follows: Figure 4 As shown. Among them, Figure 4 This is the UV-visible absorption spectrum of the transparent polymer film with tunable refractive index.

[0088] according to Figure 4 It can be seen that the transparent polymer film with adjustable refractive index has no absorption in the 850nm communication band and can be used in the field of optical communication.

[0089] 5. Dielectric performance test

[0090] The broadband dielectric spectrum analysis (test frequency 10 -1 -10 6 Hz), the result is Figure 5 As shown. Among them, Figure 5 Broadband dielectric spectra of transparent polymer films with tunable refractive index.

[0091] according to Figure 5 It can be seen that the transparent polymer film with adjustable refractive index is 10 -1 -10 6 The dielectric constant is low in the Hz range (<4) and the dielectric loss is low at 10Hz (<0.002). The dielectric constant of the material decreases after UV exposure. The lower dielectric constant will reduce the loss in signal transmission and improve the signal transmission speed and stability.

[0092] 6. Refractive index contrast and tunable performance test

[0093] The molar content of compound II is positively correlated with the UV exposure time. In order to illustrate the effect of the molar content of compound II on the refractive index properties of the prepared transparent polymer film with adjustable refractive index, the compound PMETPA prepared in Example 1 was subjected to different UV exposure treatments, specifically, the UV exposure was 0, 1, 2, 4, and 6 minutes, and the obtained transparent polymer film sample was placed on the sample stage of an ellipsometer, 400-1600nm light was incident at 75°, the reflected light was received, and the polarization and intensity information was used as data to calculate the refractive index curve of the film sample at different wavelengths. The results are as follows: Figure 6 As shown. Among them, Figure 6 These are the refractive index contrast test results under different UV exposure times.

[0094] according to Figure 6 It can be seen that the transparent polymer films prepared by different UV exposure times all have a large refractive index contrast (Δn=0.01-0.07), and the refractive index contrast changes with the UV exposure time, that is, they have good refractive index tunability.

[0095] At the same time, this paper also tested the molar content of compound II obtained under different UV exposure times, as shown in Table 1.

[0096] Table 1: Test results of the molar content of compound II generated under different UV exposure times

[0097] Exposure time Molar content of compound II Refractive Index Exposure time Molar content of compound II Refractive Index 0 0 1.5744 120s 69 mol% 1.6253 10s 2.64mol% 1.5783 240s 71 mol% 1.6292 20s 9.78mol% 1.5852 360s 76 mol% 1.6382 30s 19 mol% 1.5972 600s 83 mol% 1.6433 60s 38 mol% 1.6021

[0098] According to Table 1, the molar content of compound II increases with the extension of UV exposure time, and the refractive index also increases. Among them, after the exposure time is extended to 120s, the increase trend of the molar content of compound II slows down, and the increase in the refractive index is very small. Since long-term UV exposure will increase the process cost, the preferred UV exposure time is preferably 120s.

[0099] 7. Transparency test

[0100] The UV transmittance of the transparent polymer film with adjustable refractive index prepared in Example 1 was tested using a Lambda 750S UV / visible / near-infrared spectrophotometer. Specifically, the transparent polymer film with adjustable refractive index was stacked into a film sample of 30-50 μm, which was placed in the sample slot of the UV-visible spectrometer to test its transmittance performance (ultraviolet region ±1 nm, visible region 500 nm ±2 nm, film sample surface perpendicular to the light path, test wavelength 200-1700 nm), and the transmittance was recorded. The result was: Figure 7 As shown. Among them, Figure 7 The UV transmittance test results of the transparent polymer film with adjustable refractive index.

[0101] according to Figure 7 It can be seen that the transparent polymer film with adjustable refractive index prepared in Example 1 has excellent transparency in the range of 200-1700 nm, and the transmittance of the film is 99%.

[0102] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0103] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A transparent polymer film with adjustable refractive index, characterized in that: The ingredients include: (a) a compound I of structure (1); and, (b) Compound I is cross-linked by ultraviolet light to form compound II of structure (2); Where n is the number of structural units; R1 is H, halogen atom, fluorinated methyl, C 1-20 Alkyl, C 1-20 Any of an alkoxy group and an allyloxy group.

2. The transparent polymer film according to claim 1, characterized in that: The material composition consists of compound I and compound II; The molar content of compound II is 2.64-83% of the total of compound I and compound II.

3. The transparent polymer film according to claim 2, characterized in that: The material composition consists of compound I and compound II; The molar content of compound II is 38-69% of the total of compound I and compound II.

4. The transparent polymer film according to claim 1, characterized in that: Compound I comprises:

5. A method for producing a transparent polymer film according to any one of claims 1 to 4, characterized in that: Include: The hydroxyethyl methacrylate and 4-(R1) cinnamic acid are subjected to an esterification reaction to synthesize [4-(R1) cinnamic acid] hydroxyethyl methacrylate; The [4-(R1) cinnamic acid] hydroxyethyl methacrylate is dissolved in a solvent system containing a catalyst to perform a free radical polymerization reaction to synthesize compound I; After coating the solvent in which compound I is dissolved, ultraviolet light crosslinking and thermal curing are sequentially performed to obtain the product.

6. The manufacturing method according to claim 5, characterized in that: The solvent is one of N,N-dimethylformamide, propylene glycol methyl ether acetate and dimethyl sulfoxide.

7. The manufacturing method according to claim 5, characterized in that: The mass concentration of the [4-(R1) cinnamic acid] hydroxyethyl methacrylate dissolved is 0.01-1.0 mol / L; The molar ratio of the [4-(R1) cinnamic acid] hydroxyethyl methacrylate solution to the catalyst is 100-500:

1.

8. The manufacturing method according to claim 7, characterized in that: The mass concentration of compound I in the solvent is 3-5wt%.

9. The manufacturing method according to any one of claims 6 to 8, characterized in that: When the ultraviolet light crosslinking is performed, the wavelength of the ultraviolet light is 200-380nm and the time is 10-600s; And / or, the thermal curing temperature is 100-110° C. and the time is 15-60 min.

10. Use of the transparent polymer film with adjustable refractive index according to any one of claims 1 to 5 in optical waveguides and microelectronic materials.

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