Polymer crosslinking agent, its preparation method and application in organic electro-optical material

Abstract

The application belongs to the technical field of optical functional materials, and particularly relates to a polymer crosslinking agent, a preparation method thereof and application thereof in organic electro-optical materials. The application provides a polymer crosslinking agent with a structure shown in formula I. The application introduces a crosslinking group on the polymer crosslinking agent. The group can release nitrogen to generate a reactive carbene under light (350-450 nm ultraviolet light irradiation) or heating. The carbene is inserted into a C-H bond to react with a polymer framework and a chromophore to form a stable three-dimensional network structure. The application is suitable for improving the glass transition temperature and thermal stability of various structural materials, and has universality and wide applicability. The technology provides a new way for developing flexible optoelectronic devices, and the low-energy-consumption and high-precision crosslinking characteristics have broad prospects in the fields of wearable devices and integrated photon chips.

Description

Technical Field

[0001] This invention belongs to the field of optical functional materials technology, specifically relating to a polymer crosslinking agent, its preparation method, and its application in organic electro-optic materials. Background Technology

[0002] Organic electro-optic materials, as core functional materials in high-speed optical communication, photonic computing, and sensing, derive their electro-optic activity from the non-centrosymmetric arrangement of chromophores induced by an external electric field. However, this arrangement relaxes when the ambient temperature approaches or exceeds the material's glass transition temperature (Tg), leading to a rapid decay in electro-optic activity and severely limiting the long-term reliability and lifespan of devices. Therefore, effectively improving the Tg of organic electro-optic materials and thus ensuring their long-term thermal stability has become a core technical problem urgently needing to be solved in the field of organic electro-optic materials.

[0003] To address the aforementioned issues, common solutions include: First, using high-Tg polymers as the host and chromophore molecules as the guest, incorporating chromophore molecules into the high-Tg polymer, or introducing branched or dendritic substituents into the chromophore molecule structure to increase Tg, which to some extent suppresses the thermal relaxation behavior of the chromophore and alleviates the decay of electro-optic activity. However, such strategies often involve complex molecular synthesis processes, resulting in high preparation costs and limited improvement in thermal stability, making it difficult to meet the application requirements of high-performance devices. Second, crosslinking is widely considered an effective method to enhance the long-term thermal stability of electro-optic polymers. For example, Diels-Alder thermal crosslinking has been shown to significantly improve thermal stability while maintaining high electro-optic activity (Advanced Science 2023, 10 (31), 2304229.). However, such thermal crosslinking usually requires temperatures above 130 °C to overcome the activation energy barrier, which not only limits compatibility with semiconductor lithography processes but also poses a risk of mismatch between the polarization window and the crosslinking window, leading to incomplete chromophore arrangement or low crosslinking efficiency, thus affecting the final device performance.

[0004] In recent years, carbene-mediated crosslinking strategies have attracted much attention due to their high efficiency and versatility. However, although existing technologies have reported that bisacrylidine small molecule crosslinking agents can be used to prepare high-density elastic circuits and multifunctional semiconductor patterns, there is very little research on how to extend small molecule crosslinking agents to high molecular weight polymer crosslinking systems and apply them to organic electro-optic materials. Summary of the Invention

[0005] The purpose of this invention is to provide a polymer crosslinking agent, its preparation method, and its application in organic electro-optic materials. The polymer crosslinking agent provided by this invention can be used in organic electro-optic materials and improve the thermal stability of organic electro-optic materials.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a polymer crosslinking agent having the structure shown in Formula I:

[0008] Formula I;

[0009] In equation I, x + y + z = 1;

[0010] R1 and R2 are independently one or more of ester groups, substituted ester groups, amide groups, and substituted amide groups;

[0011] R3 contains one or more substituents selected from bispropidine, diazo, and azide.

[0012] Preferably, R3 has any one of the structures of Formula 1 to Formula 20:

[0013]

[0014] R4 is NO2, H, or a halogen group.

[0015] The present invention also provides a method for preparing the polymer crosslinking agent described in the above technical solution, comprising the following steps:

[0016] Monomer 1, monomer 2, monomer 3, an alkaline substance and an initiator are dissolved in an organic solvent and polymerized under heating conditions to obtain the polymer crosslinking agent.

[0017] The structural formula of monomer 1 is: The structural formula of monomer 2 is: ;

[0018] The structural formula of monomer 3 is: .

[0019] Preferably, the alkaline substance includes one or more of triethylamine, tributylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, N,N-dimethylaniline, 1,8-diazabicyclo[5.4.0]undec-7-ene and 1,5-diazabicyclo[4.3.0]non-5-ene.

[0020] Preferably, the initiator comprises a mixture of N,N-dimethyl-p-toluidine and benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or azobismethoxyisoheptanenitrile;

[0021] The organic solvent includes one or more of anhydrous toluene, anhydrous N,N-dimethylformamide, and anhydrous dimethyl sulfoxide.

[0022] Preferably, the monomer 3 is prepared by the following method:

[0023] R3OH and methacryloyl chloride or acryloyl chloride were esterified under alkaline conditions to obtain monomer 3.

[0024] The present invention also provides the application of the polymer crosslinking agent described in the above technical solution or the polymer crosslinking agent prepared by the above preparation method in organic electro-optic materials.

[0025] The present invention also provides an organic electro-optic polymer, which is obtained by crosslinking the polymer crosslinking agent and chromophore; the polymer crosslinking agent is the polymer crosslinking agent described in the above technical solution or the polymer crosslinking agent prepared by the preparation method described above.

[0026] This invention also provides a method for preparing the organic electro-optic polymer described in the above technical solution, comprising the following steps:

[0027] The electro-optic material is obtained by mixing a solution of a polymer crosslinking agent and a chromophore and then drying the mixture.

[0028] After sputtering the electro-optic material onto the electrode, it is then subjected to electric field polarization and photocrosslinking in sequence to obtain an organic opto-polymer.

[0029] The present invention also provides an organic electro-optic polymer film, the material of which is the organic electro-optic polymer described in the above technical solution or the organic electro-optic polymer prepared by the above preparation method.

[0030] This invention provides a polymer crosslinking agent with the structure shown in Formula I. By introducing crosslinking groups onto the polymer crosslinking agent, these groups release nitrogen gas to generate reactive carbenes under light irradiation (350-450 nm ultraviolet light) or heating. The carbenes then undergo crosslinking reactions with the polymer framework and chromophores via CH bond insertion, forming a stable three-dimensional network structure. This structure is suitable for improving the glass transition temperature and thermal stability of various structural materials, exhibiting versatility and wide applicability. This technology provides a new approach for developing flexible optoelectronic devices, and its low-energy consumption and high-precision crosslinking characteristics show broad prospects in wearable devices and integrated photonic chips.

[0031] Furthermore, this invention introduces a polymer crosslinking agent into the organic electro-optic polymer system, achieving in-situ crosslinking between the polymer crosslinking agent and chromophore molecules through photoinitiation. While maintaining a high electro-optic coefficient (>100 pm / V), it increases the material's Tg to above 150 °C, thereby improving the thermal orientation stability of the organic electro-optic material, preventing electro-optic coefficient decay, and thus meeting the long-term stability requirements under harsh environments such as high temperature and high humidity.

[0032] Data from the examples show that the organic electro-optic polymer system provided by the present invention obtains electro-optic properties after being polarized by an electric field. The electro-optic coefficient thermal stability was tested and verified after cross-linking by 365 nm light. Compared with the uncross-linked chromophore, the electro-optic coefficient exhibits excellent long-term thermal stability (85℃, 500 h). Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 The polymer crosslinking agent PW1 in Example 1 of this invention 1 H NMR spectrum;

[0035] Figure 2 The polymer crosslinking agent PW2 in Example 2 of this invention 1 H NMR spectrum;

[0036] Figure 3 The Fourier transform infrared spectra of the polymer crosslinking agent PW1 before and after photocrosslinking in Example 4 of the present invention are shown below.

[0037] Figure 4 The Fourier transform infrared spectra of the polymer crosslinking agent PW2 before and after photocrosslinking in Example 4 of the present invention are shown below.

[0038] Figure 5 The image shows the ultraviolet-visible spectra of the electro-optic material thin films prepared in Examples 3-2 of this invention during the photocrosslinking process.

[0039] Figure 6 The image shows the ultraviolet-visible spectra of the electro-optic material thin films prepared in Examples 3-3 of this invention during the photocrosslinking process.

[0040] Figure 7 This is a DSC curve of the electro-optic material thin film after processing in Example 6 of the present invention;

[0041] Figure 8 This is a TGA curve of the electro-optic material thin film after processing in Example 7 of the present invention;

[0042] Figure 9 This is a graph showing the thermal stability of the electro-optic coefficient of the electro-optic material film treated in Example 8 of the present invention after long-term heating (500 hours) under vacuum conditions at 85 °C. Detailed Implementation

[0043] This invention provides a polymer crosslinking agent having the structure shown in Formula I:

[0044]

[0045] Equation I; In Equation I, x + y + z = 1;

[0046] R1 and R2 are independently one or more of ester groups, substituted ester groups, amide groups, and substituted amide groups;

[0047] R3 contains one or more substituents selected from bispropidine, diazo, and azide.

[0048] As one embodiment of the present invention, R3 has any one of the structures of Formula 1 to Formula 20:

[0049]

[0050] R4 is NO2, H, or a halogen group;

[0051] In one embodiment of the present invention, the halogen group is one or more of F, Cl, Br and I.

[0052] The present invention also provides a method for preparing the polymer crosslinking agent described in the above technical solution, comprising the following steps:

[0053] Monomer 1, monomer 2, monomer 3, an alkaline substance and an initiator are dissolved in an organic solvent and polymerized under heating conditions to obtain the polymer crosslinking agent.

[0054] The structural formula of monomer 1 is: The structural formula of monomer 2 is: ;

[0055] The structural formula of monomer 3 is: .

[0056] As one embodiment of the present invention, the preparation method of monomer 3 is as follows:

[0057] R3OH and methacryloyl chloride or acryloyl chloride were esterified under alkaline conditions to obtain monomer 3;

[0058] In one embodiment of the present invention, the methacryloyl chloride or acryloyl chloride is preferably used in solution form; the alkaline conditions may be provided by triethylamine; and the reaction solvent for the esterification reaction may be one or more of anhydrous dichloromethane, trichloromethane, and tetrahydrofuran.

[0059] Specifically, the esterification reaction steps include: dissolving R3OH and triethylamine and cooling to -10~0 °C, then adding a solution of methacryloyl chloride or acryloyl chloride dropwise to the resulting solution for mixing; the mixing time can be 10~30 min; the mixing can be carried out under stirring conditions.

[0060] In one embodiment of the present invention, the molar ratio of R3OH to methacryloyl chloride or acryloyl chloride can be 1:1 to 1:3, specifically 1:1, 1:1.5, 1:2 or 1:3. In another embodiment of the present invention, the esterification reaction temperature can be 25 to 42°C, and the reaction time can be 12 to 24 hours.

[0061] In one embodiment of the present invention, after the esterification reaction, the reaction solution is further diluted with dichloromethane, ethyl acetate, or diethyl ether, and the diluted solution is then washed and dried sequentially to obtain monomer 3. In another embodiment of the present invention, the washing solution includes one or more of dilute HCl solution, saturated NH4Cl solution, saturated Na2CO3 solution, saturated NaHCO3 solution, and saturated NaCl solution; the drying reagent can be anhydrous MgSO4.

[0062] In one embodiment of the present invention, the alkaline substance includes one or more of triethylamine, tributylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, N,N-dimethylaniline, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN).

[0063] In one embodiment of the present invention, the initiator includes a mixture of N,N-dimethyl-p-toluidine and benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or azobismethoxyisoheptanenitrile.

[0064] In one embodiment of the present invention, the organic solvent includes one or more of anhydrous toluene (TOL), anhydrous N,N-dimethylformamide (DMF), and anhydrous dimethyl sulfoxide (DMSO).

[0065] In one embodiment of the present invention, the polymerization temperature can be 30~65℃, specifically 30℃, 35℃, 50℃ or 65℃. In another embodiment, when the initiator is N,N-dimethyl-p-toluidine and benzoyl peroxide, the polymerization temperature is preferably 35℃; when the initiator is azobisisobutyronitrile, the polymerization temperature is preferably 65℃; when the initiator is azobisisoheptanenitrile, the polymerization temperature is preferably 50℃; and when the initiator is azobismethoxyisoheptanenitrile, the polymerization temperature is preferably 30℃.

[0066] This invention also provides an organic electro-optic polymer, obtained by crosslinking the polymer crosslinking agent and chromophore described in the above technical solution. As one embodiment of this invention, the mass percentage of the chromophore in the mixture of the polymer crosslinking agent and chromophore can be 25-75%.

[0067] In one embodiment of the present invention, the chromophore may be JRD1, which is preferably prepared in accordance with J. Mater. Chem. C, 2016, 4, 3119-3124.

[0068] This invention also provides a method for preparing the organic electro-optic polymer described in the above technical solution, comprising the following steps:

[0069] The electro-optic material is obtained by mixing a solution of a polymer crosslinking agent and a chromophore and then drying the mixture.

[0070] After sputtering the electro-optic material onto the electrode, it is then subjected to electric field polarization and cross-linking in sequence to obtain an organic opto-polymer.

[0071] The present invention also provides an organic electro-optic polymer film, the material of which is the organic electro-optic polymer described in the above technical solution.

[0072] In one embodiment of the present invention, the crosslinking can be photocrosslinking or thermal crosslinking.

[0073] In one embodiment of the present invention, the photocrosslinking is performed by irradiating an electro-optic material that has been polarized by an electric field with ultraviolet light; the wavelength of the ultraviolet light can be 350~450 nm; and the light intensity density of the ultraviolet light irradiation can be 2~10 mw / cm². 2 Specifically, it can be 2 mw / cm 2 3 mw / cm 2 5 mw / cm 2 Or 10 mw / cm 2 The duration of ultraviolet irradiation can be 2 to 20 minutes, specifically 2 minutes, 5 minutes, 10 minutes or 20 minutes.

[0074] In one embodiment of the present invention, the temperature of the thermal crosslinking can be 120~170℃, specifically 120℃, 130℃, 140℃, 150℃, 160℃ or 170℃; the time can be 5~10min, specifically 5min, 6min, 7min, 8min, 9min or 10min.

[0075] The present invention also provides a method for preparing the above-described organic electro-optic polymer thin film, comprising the following steps:

[0076] A solution of a polymer crosslinking agent and a chromophore are mixed, and the resulting mixture is coated onto the substrate surface and dried to form a film, thus obtaining an electro-optic material thin film.

[0077] After sputtering the electro-optic material thin film onto the electrode, it is then subjected to electric field polarization and crosslinking in sequence to obtain an organic electro-optic polymer thin film.

[0078] In this invention, the only difference between the preparation process of the organic electro-optic polymer film and the organic electro-optic polymer is that film formation is also included; other conditions are the same and will not be described again. In this invention, the electro-optic coefficient of the organic electro-optic polymer film can be 100~500 pm / V.

[0079] In this invention, the electro-optic material thin film obtains a large electro-optic coefficient after being polarized by an electric field. When exposed to ultraviolet light or heated, carbene is generated and cross-links with the polymer backbone and chromophore molecules through CH insertion reaction to form a three-dimensional network structure, which greatly improves the thermal stability of the electro-optic coefficient of the organic electro-optic material.

[0080] The preparation of the organic electro-optic polymer thin film provided by this invention has the following advantages:

[0081] 1. Mild and efficient: At room temperature, the polymer crosslinking agent can be activated by ultraviolet irradiation to generate a carbene intermediate, which then undergoes a crosslinking reaction with the chromophore molecule in a short time.

[0082] 2. Controllability of conditions: By adjusting the light intensity, wavelength and time, the cross-linking sites and network density can be precisely controlled.

[0083] 3. Polymer universality: This technology is applicable to materials rich in CH bonds. The polymer crosslinking agent inserts photo-induced carbene into materials rich in CH bonds to form a through-link crosslinking network, which significantly improves the mechanical strength and thermal stability of the material.

[0084] To further illustrate the present invention, the following detailed description of the invention's solutions, in conjunction with the accompanying drawings and embodiments, is provided, but should not be construed as limiting the scope of protection of the present invention.

[0085] Example 1

[0086] The synthetic route for the diazinon-propidium group polymer (PW1) is as follows:

[0087]

[0088] In PW1, x = 74%; y = 26%;

[0089] Synthesis of compound 3a:

[0090] 4-[3-(trifluoromethyl)-3H-bisacrylidine-3-yl]benzyl alcohol (compound 2a, 0.52 g, 2.4 mmol) and triethylamine (0.5 mL, 3.6 mmol) were dispersed in ultradry dichloromethane (3 mL) and cooled to 0 °C. Methacryl chloride (compound 1, 0.38 g, 3.6 mmol) was added dropwise. The resulting solution was stirred at 0 °C for 30 min, and then reacted at 25 °C for 12 h. After the reaction was complete, ethyl acetate was added to the reaction solution, and the mixture was extracted and washed with saturated NH4Cl solution, saturated NaHCO3 solution, and saturated NaCl solution in that order. Finally, the solvent was removed by drying with anhydrous MgSO4, and the mixture was dried under vacuum to obtain compound 3a (0.50 g, 1.75 mmol).

[0091] PW1 synthesis:

[0092] Under nitrogen atmosphere, compound 3a (monomer 3, 0.50 g, 1.75 mmol), methyl methacrylate (MMA, 0.72 g, 7.0 mmol), and azobisisobutyronitrile (V-65, 0.043 g, 0.172 mmol) were dissolved in ultra-dry toluene (10 mL). The resulting mixture was stirred at 50 °C in the dark for 12 h to obtain a viscous polymer solution. The viscous polymer solution was precipitated in n-hexane, and the polymer was collected by filtration. It was then dissolved again in THF, and methanol was added dropwise to the solution to obtain a precipitate. The precipitate was filtered and dried under vacuum in the dark at room temperature to obtain polymer PW1 (0.88 g).

[0093] Figure 1 For polymer PW1 1 H NMR spectrum.

[0094] Example 2

[0095] The synthetic route for the diazo-group polymer (denoted as PW2) in this embodiment is as follows:

[0096]

[0097]

[0098] In PW2, x=38%; y=52%; z=10%;

[0099] Synthesis of compound 3b:

[0100] 1-Adamantanol (compound 2b, 0.38 g, 2.5 mmol) and triethylamine (0.52 mL, 3.75 mmol) were dissolved in ultra-dry dichloromethane (3 mL) under nitrogen atmosphere. After the solution was cooled to 0°C, methacryloyl chloride (compound 1, 0.17 g, 3.75 mmol) was added dropwise to the stirred solution. The reaction mixture was stirred at 0°C for 30 min, and then the reaction vessel was placed in an oil bath preheated to 42°C for 12 h. Dichloromethane was then added to the reaction solution, and the mixture was extracted and washed with saturated NaHCO3 solution and saturated NaCl solution, respectively. Finally, the solvent was removed by drying with anhydrous MgSO4, and then the mixture was dried under vacuum to obtain compound 3b (0.44 g, 2 mmol).

[0101] Synthesis of compound 3c:

[0102] Under nitrogen atmosphere, methacryloyl chloride (compound 1, 0.23 g, 5.0 mmol), 2-hydroxyethyl-2-diazo-2-(4-nitrophenyl)acetic acid (compound 2c, 1.38 g, 5.5 mmol), and triethylamine (1.15 mL, 8.25 mmol) were dissolved in ultradry dichloromethane (6 mL). The mixture was cooled to 0 °C, stirred for 30 min, and then reacted at room temperature for 12 h. After removing the solvent, the residue was dissolved in diethyl ether and washed successively with dilute HCl solution, saturated Na₂CO₃ solution, and saturated NaCl solution. The washing product was dried over anhydrous MgSO₄ and the solvent was removed to give compound 3c (0.64 g, 2 mmol).

[0103] Synthesis of compound PW2:

[0104] Compounds 3b (monomer 2, 0.44 g, 2 mmol), 3c (monomer 3, 0.64 g, 2 mmol), and N,N-dimethylacrylamide (monomer 1, 0.59 g, 6 mmol) were dissolved in ultra-dry DMF. Azobisisobutyronitrile (0.03 g, 0.12 mmol) was added as an initiator. The reaction solution was placed in an ice bath at 0 °C and degassed by nitrogen purging for 30 min. After purging, the solution was placed in an oil bath preheated to 50 °C and reacted under a nitrogen atmosphere for approximately 12 hours. The resulting polymer solution was precipitated in diethyl ether. The precipitated polymer was dissolved in dichloromethane and precipitated again in diethyl ether. The resulting polymer was filtered and dried under vacuum to obtain polymer PW2 (1.42 g).

[0105] PW2 1 The H NMR spectrum is shown in [reference]. Figure 2 .

[0106] Example 3

[0107] This embodiment provides three types of electro-optic material thin films, the preparation methods of which include:

[0108] 1) Add 15.0 mg of polymethyl methacrylate (PMMA) to 230.0 mg of 1,1,2-trichloroethane and stir for 2 hours until the PMMA is completely dissolved. Then add 5.0 mg of chromophore JRD1 and continue stirring until the chromophore is fully dissolved. Filter the resulting mixed solution through a 0.22 μm filter membrane and let it stand for half an hour to obtain a mixed solution with a mass fraction of 8% (25 wt% chromophore, i.e., the mass of the chromophore / (mass of polymethyl methacrylate + chromophore) is 25%). Spin-coating was used to coat the film on an ITO glass substrate. After film formation, the sample was first heated on a 50 ℃ heating stage for 5 min, and then transferred to a vacuum drying oven to dry overnight. The film thickness was approximately 2.0 μm.

[0109] 2) The preparation method of the second type of photocrosslinked electro-optic material thin film is the same as 1), except that PMMA is replaced with PW1.

[0110] 3) The preparation method of the third type of photocrosslinked electro-optic material thin film is the same as 1), except that PMMA is replaced with PW2.

[0111] Example 4

[0112] Fourier transform infrared (FTIR) spectra of the polymer crosslinking agents in Examples 1 and 2 during the photocrosslinking process were tested, and the curves are shown below. Figures 3-4 As shown, Figure 3 The corresponding Example 1 polymer crosslinking agent contains a diacrylidine group, which generates carbene intermediates and diazonium intermediates after ultraviolet irradiation. This process is called activation. After continuous ultraviolet irradiation, all the diacrylidine groups will be converted into carbene intermediates and crosslinked. Figure 4 The corresponding Example 2 polymer crosslinking agent contains diazo groups. After ultraviolet irradiation, all diazo groups are converted into carbene intermediates, resulting in a crosslinking reaction. Figure 3 and Figure 4 This indicates that the crosslinking groups (bisacrididine group and diazo group) in the polymer crosslinking agent will achieve photocrosslinking after ultraviolet light treatment.

[0113] Example 5

[0114] The organic electro-optic thin film prepared in Example 3-2) was tested by using 365 nm ultraviolet light at 10 mw / cm². 2 Illumination; the organic electro-optic thin film prepared in Examples 3-3) was subjected to 365 nm ultraviolet light at 2 mw / cm². 2 After illumination, the crosslinking time was finally detected using ultraviolet-visible absorption spectroscopy, and the resulting curve is shown below. Figures 5-6 As shown, the crosslinking time depends on the type of polymer crosslinking groups and the amount of light power used in the light treatment.

[0115] Example 6

[0116] The glass transition temperature (Tg) of the three organic electro-optic thin films prepared in Examples 3-1 and 5 was measured using differential scanning calorimetry (DSC), and the obtained curves are shown below. Figure 7 As shown, this indicates that polymer crosslinking agents can effectively increase the glass transition temperature of materials.

[0117] Example 7

[0118] The thermal decomposition temperature (Td) of the three organic electro-optic thin films prepared in Examples 3-1 and 5 was measured using a thermogravimetric analyzer (TGA), and the obtained curves are shown below. Figure 8 As shown, this indicates that polymer crosslinking agents can effectively increase the thermal decomposition temperature of materials.

[0119] Example 8

[0120] 1) The organic electro-optic thin film of Example 3-1) was subjected to contact polarization at a polarization temperature of 93°C and a polarization electric field strength range of 120 V / μm. The entire polarization process was carried out under a nitrogen atmosphere for 5 minutes. The electro-optic coefficient (r) was determined by a simple reflection method. 33 The maximum electro-optic coefficient measured was 144 pm / V@1310 nm.

[0121] 2) The polarization and testing methods for the organic electro-optic thin films in Examples 3-2) are the same as in 1), except that after polarization, a 365 nm ultraviolet lamp at 10 mw / cm² is used. 2 Crosslinking and curing were achieved by irradiation with high optical power for 20 minutes. The maximum electro-optic coefficient measured was 140 pm / V at 1310 nm.

[0122] 3) The polarization and testing methods for the organic electro-optic thin films in Examples 3-3) are the same as in 1), except that after polarization, a 365 nm ultraviolet lamp at 2 mw / cm² is used. 2 Crosslinking and curing were achieved by irradiation with high optical power for 4 minutes. The maximum electro-optic coefficient measured was 113 pm / V at 1310 nm.

[0123] Example 9

[0124] The organic electro-optic thin film prepared in Example 8 was heated to 85 °C in a vacuum environment for 500 hours to test its thermal stability. The stability curve of its electro-optic properties is shown below. Figure 9As shown, the polarized crosslinked organic electro-optic thin film exhibits good stability in its electro-optic properties. After being placed at 85°C for 500 hours, the electro-optic properties of the crosslinked films in Examples 8-2) and 8-3) remained above 93% of their initial values. In contrast, the electro-optic coefficient of the uncrosslinked chromophore molecular film in Example 8-1) showed very poor stability, decreasing to 11% of its initial value. This demonstrates that the polymer crosslinking agent has a very good effect on improving the thermal stability of organic electro-optic materials.

[0125] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An organic electro-optic polymer, characterized in that, It is obtained by crosslinking the polymer crosslinking agent and the chromophore; the polymer crosslinking agent has the structure shown in Formula I: Equation I; In equation I, x + y + z = 1; R1 and R2 are independently one or more of ester groups, substituted ester groups, amide groups, and substituted amide groups; R3 has any of the structures from Equation 1 to Equation 20: ； R4 is NO2, H, or a halogen.

2. The organic electro-optic polymer according to claim 1, characterized in that, The preparation method of the polymer crosslinking agent includes the following steps: Monomer 1, monomer 2, monomer 3, an alkaline substance and an initiator are dissolved in an organic solvent and polymerized under heating conditions to obtain the polymer crosslinking agent. The structural formula of monomer 1 is: The structural formula of monomer 2 is: ; The structural formula of monomer 3 is: .

3. The organic electro-optic polymer as described in claim 2, characterized in that, The alkaline substance includes one or more of triethylamine, tributylamine, pyridine, 4-dimethylaminopyridine, N,N-diisopropylethylamine, N,N-dimethylaniline, 1,8-diazabicyclo[5.4.0]undec-7-ene and 1,5-diazabicyclo[4.3.0]non-5-ene.

4. The organic electro-optic polymer as described in claim 2, characterized in that, The initiator includes a mixture of N,N-dimethyl-p-toluidine and benzoyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or azobismethoxyisoheptanenitrile; The organic solvent includes one or more of anhydrous toluene, anhydrous N,N-dimethylformamide, and anhydrous dimethyl sulfoxide.

5. The organic electro-optic polymer as described in claim 2, characterized in that, The preparation method of monomer 3 is as follows: R3OH and methacryloyl chloride or acryloyl chloride were esterified under alkaline conditions to obtain monomer 3.

6. The method for preparing the organic electro-optic polymer according to claim 1, comprising the following steps: The electro-optic material is obtained by mixing a solution of a polymer crosslinking agent and a chromophore and then drying the mixture. After sputtering the electro-optic material onto an electrode, it is then subjected to electric field polarization and photocrosslinking in sequence to obtain an organic electro-optic polymer.

7. An organic electro-optic polymer film, wherein the material is the organic electro-optic polymer of claim 1 or the organic electro-optic polymer prepared by the preparation method of claim 6.

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