A method for preparing a high refractive index, colorless transparent titanium dioxide / cycloolefin copolymer composite

Abstract

The present application relates to high refractive index material preparation technical field, particularly to a kind of high refractive index, colorless transparent titanium dioxide / cycloolefin copolymer composite preparation method.The preparation method includes the following steps: under the condition of anhydrous oxygen-free, monomer HBM is dissolved with the functional reaction site-containing norbornene derivative in solvent, catalyst is added to carry out reaction, and termination reaction is obtained cycloolefin copolymer;Cycloolefin copolymer is dissolved in solvent, and hydrolysis condensation reaction is carried out by adding tetrabutyl titanate, and titanium dioxide / cycloolefin copolymer composite material is obtained;The structural formula of monomer HBM is as shown below:;The structural formula of functional reaction site-containing norbornene derivative is at least one of the following structural formula M1~M4:。The refractive index of the titanium dioxide / cycloolefin copolymer composite material is between 1.578~1.701, excellent light transmittance is shown at 589 nm and has high glass transition temperature.

Description

Technical Field

[0001] This invention relates to the field of high refractive index material preparation technology, and in particular to a method for preparing a high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material. Background Technology

[0002] Cyclic olefin copolymers (COPs), as a class of high-performance engineering plastics, have attracted much attention due to their excellent optical transparency, superior thermal stability, and outstanding processability. These materials exhibit high transmittance in the visible light region and possess characteristics such as low birefringence, low water absorption, and good chemical stability, making them indispensable key materials in high-end optical devices, medical packaging, and electronic information fields. With the widespread adoption of multi-camera systems in smartphones, the rise of AR / VR devices, and the rapid development of automotive optical systems, the market demand for high-performance optical polymers is experiencing explosive growth.

[0003] In optical applications, refractive index is one of the key parameters for evaluating the performance of polymer materials. High refractive index materials can effectively reduce lens thickness and optical system volume, meeting the demands of modern optical equipment for lightweighting and miniaturization. Especially in applications such as mobile phone lenses, automotive cameras, and security monitoring lenses, high refractive index optical materials can significantly simplify optical design and improve image quality. Currently, traditional methods for increasing the refractive index of polymers mainly include introducing atoms with high molar refractive indices (such as sulfur and halogens), adding conjugated groups, or introducing aromatic structures. For example, Jian et al. synthesized carbazolyl and indole-substituted norbornene monomers, synthesized cyclic olefin polymers through ring-opening metathesis polymerization, and then vulcanized the polymer using a thiol-alkenyl click reaction. Although the introduction of sulfur atoms improved the refractive index to some extent, it still could not exceed 1.70, and the vulcanized polymer contained color, limiting its further application in the optical field. Summary of the Invention

[0004] Based on the above, this invention provides a method for preparing a high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material. The high-refractive-index titanium dioxide / cyclic olefin copolymer composite material prepared by the method of this invention exhibits excellent properties (refractive index = 1.578~1.701) and excellent light transmittance (transmittance at 589 nm > 90%).

[0005] To achieve the above objectives, the present invention provides the following solution: One of the technical solutions of this invention is a method for preparing a high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material, comprising the following steps: Step 1: Under anhydrous and oxygen-free conditions, monomer HBM (external type -1,4,4a,9,9a,10-hexahydro-9,10(1',2')-bridged benzene-1,4-bridged methylene anthracene) and norbornyl derivative containing functional reaction sites are dissolved in a solvent, a catalyst is added to carry out the reaction, and the reaction is terminated to obtain cyclic olefin copolymer; Step 2: Dissolve the cyclic olefin copolymer in a solvent, add tetrabutyl titanate to carry out a hydrolysis-condensation reaction, and obtain a high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material. The structural formula of the monomer HBM is shown below: ; The structural formula of norbornene derivatives containing functional reaction sites is at least one of the following structural formulas M1 to M4: .

[0006] The second technical solution of the present invention is a high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material prepared by the above preparation method.

[0007] The third technical solution of this invention is the application of the above-mentioned high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material in the preparation of optical materials.

[0008] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves highly efficient control over the Tg, molecular weight and its distribution, and segmental microstructure of the composite material by inserting different monomers and varying the weight fraction of titanium dioxide particles, and can also prepare high-performance high-refractive-index copolymers. The Tg of the composite material prepared by this invention is adjustable between 171.38 °C and 218.43 °C. By adjusting the proportion of titanium dioxide particles added, the refractive index of the composite material can be increased. When the content of titanium dioxide particles in the composite material reaches 40%, the refractive index can be increased to 1.701. The light transmittance at 589 nm exceeds 90%. Notably, the commercially available Grubbs catalyst used in this invention can efficiently catalyze the copolymerization of the two, showing commercial potential. In addition, the titanium dioxide / cyclic olefin copolymer synthesized in this way also maintains high heat resistance and good hydrophilicity. The strategy for synthesizing high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite materials has not been reported in many technical fields, and it is expected to broaden the application of this composite material in the field of optical lenses. Attached Figure Description

[0009] Figure 1 NMR spectra of the cycloolefin monomers obtained in Example 2 of this invention 1 H-NMR spectrum; Figure 2NMR spectra of the cycloolefin monomers obtained in Example 2 of this invention 13 C-NMR spectrum; Figure 3 NMR of the cyclic olefin copolymer obtained in Example 6 of this invention 1 H-NMR spectrum; Figure 4 NMR of the cyclic olefin copolymer obtained in Example 6 of this invention 13 C-NMR spectrum; Figure 5 The differential scanning calorimetry curve of the cyclic olefin copolymer obtained in Example 6 of the present invention; Figure 6 The differential scanning calorimetry curve of the composite material obtained in Example 16 of this invention; Figure 7 The refractive index curve of the cyclic olefin copolymer obtained in Example 6 of the present invention; Figure 8 The refractive index curve of the composite material obtained in Example 16 of the present invention; Figure 9 The transmittance curve of the cyclic olefin copolymer obtained in Example 6 of the present invention; Figure 10 The transmittance curve of the composite material obtained in Example 16 of this invention; Figure 11 The diagram shows the water contact angle of the composite materials obtained in Examples 6, 14, and 16 of this invention. Detailed Implementation

[0010] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0011] Unless otherwise specified, "room temperature" in this invention refers to 15~30℃.

[0012] Inorganic nanoparticle / polymer composites offer a novel approach to solving this problem. Nano-titanium dioxide (TiO2) is a multifunctional inorganic material with advantages such as high refractive index (n = 2.5 ~ 2.7), hydrophilicity, antibacterial properties, UV resistance, chemical stability, and thermal stability, making it an ideal inorganic component for preparing inorganic / organic polymer composites. Introducing titanium dioxide particles into cyclic olefin copolymers to prepare composites holds promise for increasing their refractive index; however, methods for preparing such high-refractive-index cyclic olefin composites have not yet been reported. Based on the above analysis, this invention designed and synthesized a series of norbornene derivatives that can react with tetrabutyl titanate. Cyclic olefin polymers with multiple functional reaction sites in the side groups were prepared via ring-opening metathesis polymerization. TiO2 nanoparticle composites were then prepared using the sol-gel method. This novel, high-performance, colorless, transparent, high-refractive-index material has broad development prospects in the field of optical lenses.

[0013] This invention addresses the limitations of existing technologies by designing and synthesizing norbornene derivatives containing functional reaction sites. Utilizing catalysts that exhibit copolymerization capabilities with HBM and norbornene derivatives containing functional reaction sites, and optimizing polymerization and post-functionalization reaction conditions, a titanium dioxide / cyclic olefin copolymer composite material with high comprehensive performance (high glass transition temperature, high refractive index, high light transmittance, etc.) is synthesized.

[0014] The first aspect of this invention provides a method for preparing a high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material, comprising the following steps: Step 1: Under anhydrous and oxygen-free conditions, monomer HBM (external type -1,4,4a,9,9a,10-hexahydro-9,10(1',2')-bridged benzene-1,4-bridged methylene anthracene) and norbornyl derivative containing functional reaction sites are dissolved in a solvent, a catalyst is added to carry out the reaction, and the reaction is terminated to obtain cyclic olefin copolymer; Step 2: Dissolve the cyclic olefin copolymer in a solvent, add tetrabutyl titanate to carry out a hydrolysis-condensation reaction, and obtain a high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material. The structural formula of the monomer HBM is shown below: ; The structural formula of norbornene derivatives containing functional reaction sites is at least one of the following structural formulas M1 to M4: .

[0015] Other common norbornene derivatives with terminal ester groups, such as 5-norbornene-2-yl acetate, are not suitable for this invention because the hydrolysis conversion rate of the ester monomer is difficult to reach 100%. The remaining unhydrolyzed ester groups cannot react with tetrabutyl titanate, resulting in a decrease in the density of effective reaction sites, which in turn affects the uniform dispersion of nanoparticles and the interfacial bonding strength. In contrast, the functional groups (hydroxyl, carboxyl, and triethoxysilane) in this invention can react directly with titanium species, resulting in high reaction efficiency and complete conversion, ensuring good dispersion of nanoparticles even with high doping levels.

[0016] This invention utilizes ring-opening metathesis polymerization to prepare cyclic olefin polymers with high refractive index groups in the main chain and functional reactive sites in the side groups, and uses the sol-gel method to prepare titanium dioxide nanoparticle composite materials. Based on the sol-gel method, functional groups that can react with tetrabutyl titanate are screened, and norbornene derivatives are designed and synthesized. Monomer M2 of this invention is prepared by reacting norbornene anhydride with 6-amino-1-hexanol; monomer M3 is prepared by reacting norbornene anhydride with 6-amino-n-hexanoic acid; monomer M4 is prepared by reacting bicyclo[2.2.1]hept-2,5-diene with vinyltrimethoxysilane.

[0017] In a preferred embodiment of the present invention, in step 1, the molar ratio of monomer HBM to norbornene derivative containing functional reaction sites is 4:1.

[0018] In a preferred embodiment of the present invention, in step 1, the reaction conditions are set as follows: the temperature is room temperature to 80 ℃, and the time is 6 to 24 h; preferably, the reaction is carried out at room temperature to 40 ℃ for 8 to 12 h (this reaction is a ring-opening metathesis polymerization reaction).

[0019] In a preferred embodiment of the present invention, in step 1, the monomer HBM is prepared by reacting bicyclic [2.2.1]hept-2,5-diene with anthracene.

[0020] In a preferred embodiment of the present invention, the structural formula of the cyclic olefin copolymer is as follows: In the formula, x and y are the degree of polymerization, 0 ≤ x ≤ 900, 0 ≤ y ≤ 800, but do not represent block copolymers.

[0021] The weight-average molecular weight of this cyclic olefin copolymer is 2.45~5.91×10⁻⁶. 4 g / mol, with molecular weight distribution between 1.73 and 1.92.

[0022] In step 1, after terminating the reaction, the resulting polymer solution is added dropwise to a precipitant, filtered, washed, and vacuum dried, then dissolved again in tetrahydrofuran, adsorbed by an adsorbent, filtered, washed, and the filter residue is collected and vacuum dried. The precipitant includes at least one of ethanol, methanol, petroleum ether, diethyl ether, and acetone (preferably methanol and / or diethyl ether); the adsorbent used for adsorption includes one of 100-500 mesh silica gel powder, 100-800 mesh neutral alumina, and activated carbon; the solvent used for washing is preferably ethanol; the vacuum drying temperature is preferably 20℃-60℃, more preferably 30℃-50℃, and most preferably 40℃.

[0023] In step 1, the molar ratio of monomer to catalyst is (200~1000):1, preferably 300:1.

[0024] In step 1, the solvent is a hydrocarbon compound, a halogenated hydrocarbon compound, a cyclic hydrocarbon compound, an aromatic hydrocarbon compound, or a cyclic ether compound, etc.; preferably benzene, toluene, xylene, ethylbenzene, chlorobenzene, dichloromethane, chloroform, tetrahydrofuran, or dioxane; more preferably chlorobenzene, dichloromethane, chloroform, tetrahydrofuran, or dioxane.

[0025] In step 1, the catalyst is a ruthenium catalyst, a molybdenum catalyst, or a tungsten catalyst, preferably a ruthenium catalyst. The ruthenium catalyst is preferably one of G1 to G3, with G3 being the most preferred.

[0026] In the catalyst, PCy3 is tricyclohexylphosphine, and Mes is 2,4,6-trimethylphenyl.

[0027] In a preferred embodiment of the present invention, the catalyst is added in step 1 by first dissolving the catalyst in a solvent and then adding it to the reaction system; after dissolving the ruthenium catalyst in the solvent, it catalyzes the ring-opening metathesis polymerization of HBM and norbornene derivatives containing functional reaction sites; the solvent for dissolving the ruthenium catalyst is kept consistent with the solvent used to dissolve the monomer, specifically at least one of hydrocarbon compounds, halogenated hydrocarbon compounds, cyclic hydrocarbon compounds, aromatic hydrocarbon compounds, or cyclic ether compounds. Preferably, it is benzene, toluene, xylene, ethylbenzene, chlorobenzene, dichloromethane, chloroform, tetrahydrofuran, or dioxane; more preferably, it is chlorobenzene, dichloromethane, chloroform, tetrahydrofuran, or dioxane.

[0028] In step 1, the reaction is terminated by adding vinyl ethyl ether. The molar ratio of the terminator to the catalyst is preferably (100~800):1, more preferably (200~400):1, and most preferably 300:1; the time for terminating the polymerization reaction is preferably 20~60 min, more preferably 30~35 min.

[0029] In a preferred embodiment of the present invention, in step 2, the solvent is a cyclic ether compound, preferably tetrahydrofuran or dioxane; the ratio of the cyclic olefin copolymer to tetrabutyl titanate is 1 g: (0.4~3) mL.

[0030] In a preferred embodiment of the present invention, the conditions for the hydrolysis-condensation reaction in step 2 are set as follows: reaction at room temperature for 1 to 4 hours; preferably 2 hours.

[0031] In step 2, the hydrolysis-condensation reaction is carried out under acidic conditions by adding hydrochloric acid to the reaction system to make it acidic.

[0032] In the method of this invention, the conversion rate of monomers is above 99%.

[0033] A second aspect of the present invention provides a high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material prepared by the above-described preparation method.

[0034] The structural formula of the high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material is shown below: In the formula, x and y are the degree of polymerization, 0 ≤ x ≤ 900, 0 ≤ y ≤ 800, but do not represent block copolymers.

[0035] The high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material has a refractive index between 1.578 and 1.701; a transmittance of >90% at 589 nm; and a glass transition temperature (Tg) between 171.38 ℃ and 218.43 ℃.

[0036] The third aspect of the present invention provides the application of the above-mentioned high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material in the preparation of optical materials.

[0037] In some embodiments of the present invention, the process further includes filtration and film formation after the hydrolysis-condensation reaction is completed.

[0038] This invention explores the effects of copolymerization of cyclic olefins with different functional reaction sites and different proportions of titanium dioxide particles on the optical and thermal properties of composite materials. Furthermore, a series of synthesized copolymers were characterized using room-temperature carbon NMR and hydrogen NMR spectroscopy to characterize the polymer's microscopic chemical structure, high-temperature GPC to test the polymer's molecular weight and distribution, DSC to study the polymer's thermal behavior, UV spectrophotometry to test the polymer's transmittance, and ellipsometer to test the polymer's refractive index. The synthesized composite materials were characterized using DSC to study the polymer's thermal behavior, UV spectrophotometry to test the polymer's transmittance, and ellipsometer to test the polymer's refractive index.

[0039] This invention primarily utilizes ring-opening metathesis polymerization to prepare cyclic olefin polymers with high refractive index groups in the main chain and functional reactive sites in the side groups. Titanium dioxide nanoparticle composites were then prepared using the sol-gel method. First, based on the sol-gel method, functional groups reacting with tetrabutyl titanate were screened, and norbornene derivatives were designed and synthesized. The effects of different ratios of HBM and norbornene derivatives on the optical properties of the composites were systematically studied. Furthermore, the effects of varying the tetrabutyl titanate ratio on the optical and thermal properties of the composites were investigated. DSC analysis showed that the glass transition temperature of the composite increased with increasing titanium dioxide weight fraction after the introduction of titanium dioxide. Optical characterization results indicated that the refractive index of the composite increased with increasing titanium dioxide particle weight fraction, reaching a maximum of 1.701, and the transmittance of the composite at 589 nm was greater than 90%.

[0040] In summary, this invention can balance the overall performance of cyclic olefin copolymers and titanium dioxide particles, and the resulting high refractive index material is expected to be widely used in the field of optical lenses.

[0041] During the preparation of the cyclic olefin copolymer, all moisture- and oxygen-sensitive operations were performed by personnel skilled in the art in an MBraun glove box or under nitrogen protection using standard Schlenk techniques.

[0042] The obtained cyclic olefin copolymers and composites underwent relevant tests. The chemical structure of the polymers was characterized using Bruker 400 MHz nuclear magnetic resonance spectroscopy with deuterated chloroform (CDCl3) or deuterated 1,1,2,2-tetrachloroethane (C2D2Cl4) as the solvent, and tetramethylsilane (TMS) as the internal standard. The thermal properties of the copolymers were characterized using a DSC Q200-TA differential scanning calorimeter (DSC) under nitrogen atmosphere and a heating / cooling rate of 10 °C / min. The molecular weight and molecular weight distribution of the copolymers were characterized using PL-GPC50 high-temperature gel permeation chromatography (GPC). Gel permeation chromatography was performed using a GPC PL GPC-220 gel permeation chromatograph with 1,2,4-trichlorobenzene (TCB) as solvent (with 0.05 wt% of 2,6-di-tert-butyl-4-methylphenol (BHT) added as an antioxidant). The test temperature was 150 °C, and the flow rate was 1.0 mL / min. Thermogravimetric analysis was performed using an E1mer Pyris1 instrument with a heating rate of 10 °C / min. The refractive index in the wavelength range of 400–1000 nm was measured using a SE-VE-L ellipsometry, and the refractive index corresponding to a wavelength of 589 nm was selected. The Abbe number, defined by the following formula, was used: ν d = ( n d-1) / ( n F - n C ),in n d , n F and n C The values ​​represent the refractive indices at wavelengths of 589 nm, 486 nm, and 656 nm, respectively. Transparency at wavelengths of 400 nm to 800 nm was measured using a Shimadzu UV-3600i UV-Vis spectrophotometer.

[0043] Unless otherwise specified, the technical solutions described in this invention are conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are all purchased from commercial channels or are publicly available. The hydrochloric acid used in the embodiments of this invention has a mass concentration of 37%.

[0044] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0045] Example 1 Synthesis of the cyclic olefin monomer HBM: 108 g (1.2 mol) of bicyclo[2.2.1]hept-2,5-diene and 42 g (0.23 mol) of anthracene were added to a 300 mL thickened glass pressure-resistant flask and reacted at 175 °C for 24 h to obtain a mixture of a yellow solution and a white solid. The mixture was filtered, and the residue was washed with petroleum ether. The residue was collected to obtain a white solid. The yellow solid obtained by rotary evaporation of the filtrate under reduced pressure was combined with the aforementioned residue. The mixture was purified by column chromatography (using n-hexane) to obtain a white crystalline solid. The solid was dried in a vacuum oven at 60 °C to obtain 45.8 g of a white solid (yield 72.6%).

[0046] Example 2 Synthesis of cycloolefin monomer M2: Norbornene anhydride (8.0 g, 48.6 mmol), 6-amino-1-hexanol (5.9 g, 50.6 mmol), toluene (100 mL), and triethylamine (0.8 mL, 5.7 mmol) were added to a round-bottom flask and stirred under reflux at 135 °C for 4 h. After the reaction was complete, the mixture was cooled to room temperature, and the solvent was removed using a rotary evaporator. The solid dissolved in dichloromethane and was washed three times each with 1M hydrochloric acid aqueous solution (20 mL) and saturated sodium chloride solution (20 mL, ultrapure water). The organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated by rotary evaporation and dried in a vacuum oven to obtain 11.0 g (86% yield) of the target product M2 (NB-OH) as a white crystalline solid.

[0047] Example 3 Synthesis of cycloolefin monomer M3: Norbornene anhydride (8.0 g, 48.6 mmol), 6-amino-n-hexanoic acid (6.6 g, 50.6 mmol), toluene (100 mL), and triethylamine (0.8 mL, 5.7 mmol) were added to a round-bottom flask and stirred under reflux at 135 °C for 4 h. After the reaction was complete, the mixture was cooled to room temperature, and the solvent was removed using a rotary evaporator. The solid dissolved in dichloromethane and was washed three times each with 1M hydrochloric acid aqueous solution (20 mL) and saturated sodium chloride solution (20 mL, ultrapure water). The organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated by rotary evaporation and dried in a vacuum oven to obtain 11.5 g (85% yield) of the target product M3 (NB-OH) as a white crystalline solid.

[0048] Example 4 Synthesis of cycloolefin monomer M4: 13.02 g (0.1 mol) of bicyclo[2.2.1]hept-2,5-diene and 75 g (0.4 mol) of vinyltrimethoxysilane were added to a 300 mL pressure-resistant flask and reacted at 175 °C for 24 h to obtain a yellowish-brown solution. The solution was then distilled under reduced pressure at 160 °C to obtain 19.8 g (77% yield) of the target product M4 (TESNB) as a colorless liquid.

[0049] Example 5 The structural formula of the cyclic olefin copolymer (HBM / M1) is as follows: x=400, y=100 The synthesis steps are as follows: Ring-opening metathesis polymerization was carried out using Grubbs III as a catalyst, and all polymerization reactions were conducted under anhydrous and oxygen-free conditions. At room temperature, using a Schlenk apparatus under nitrogen purging, 1.512 g (5.6 mmol) of the monomer HBM prepared in Example 1 and 0.23 mL (1.4 mmol) of NBMO monomer (M1) were added. Then, 50 mL of dried and degassed tetrahydrofuran solvent was added, and the mixture was magnetically stirred for 5 min to obtain a homogeneous solution. Subsequently, 20.64 mg (0.023 mmol) of catalyst (G3) was dissolved in 10 mL of tetrahydrofuran and then rapidly injected into a round-bottom flask. After reacting at room temperature under nitrogen atmosphere for 12 h, 1 mL of vinyl ether was added to terminate the reaction, and the mixture was stirred for 30 min. The polymer solution was added dropwise to 600 mL of anhydrous methanol. After filtration, washing, and vacuum drying, the product was dissolved again in tetrahydrofuran, adsorbed by an adsorbent, filtered, washed, and the filter residue was collected. The collected product was then vacuum dried at 40 °C for 16 h to obtain the cyclic olefin copolymer, which was then subjected to further characterization.

[0050] The cyclic olefin copolymer obtained in this embodiment has a glass transition temperature of ( ). T g The temperature was 171.38 °C. High-temperature GPC analysis showed a weight-average molecular weight of 3.47 × 10⁻⁶. 4 The copolymer has a g / mol content and a narrow molecular weight distribution (PDI = 1.89). It has a refractive index of 1.578, an Abbe number of 35.52, and a transmittance of over 95% in the visible light range. Specific copolymer data are shown in Table 1.

[0051] Example 6 The structural formula of the cyclic olefin copolymer (HBM / M2) is as follows: x=400, y=100 The synthesis steps are as follows: Ring-opening metathesis polymerization was carried out using Grubbs III as a catalyst, and all polymerization reactions were conducted under anhydrous and oxygen-free conditions. At room temperature, using a Schlenk apparatus under nitrogen purging, 1.512 g (5.6 mmol) of the monomer HBM prepared in Example 1 and 1.867 mL (1.4 mmol) of the monomer NB-OH prepared in Example 2 in a tetrahydrofuran solution were added. Then, 50 mL of dried and degassed tetrahydrofuran solvent was added, and the mixture was magnetically stirred for 5 min to obtain a homogeneous solution. Subsequently, 20.64 mg (0.023 mmol) of catalyst (G3) was dissolved in 10 mL of tetrahydrofuran and then rapidly injected into a round-bottom flask. After reacting at room temperature under a nitrogen atmosphere for 12 h, 1 mL of vinyl ether was added to terminate the reaction, and the mixture was stirred for 30 min. The polymer solution was added dropwise to 600 mL of anhydrous methanol. After filtration, washing, and vacuum drying, the product was dissolved again in tetrahydrofuran, adsorbed by an adsorbent, filtered, washed, and the filter residue was collected. The collected product was then vacuum dried at 40 °C for 16 h to obtain the cyclic olefin copolymer, which was then subjected to further characterization.

[0052] The cyclic olefin copolymer obtained in this embodiment has a glass transition temperature of ( ). T g The temperature was 191.70 °C. High-temperature GPC analysis showed a weight-average molecular weight of 4.76 × 10⁻⁶. 4 The copolymer has a g / mol content and a narrow molecular weight distribution (PDI = 1.92). Its refractive index is 1.585, and its Abbe number is 33.92. In the visible light range, the copolymer exhibits a transmittance of over 95%. Specific copolymer data are shown in Table 1.

[0053] Example 7 The structural formula of the cyclic olefin copolymer (HBM / M3) is as follows: x=400, y=100 The synthesis steps are as follows: Ring-opening metathesis polymerization was carried out using Grubbs III as a catalyst, and all polymerization reactions were conducted under anhydrous and oxygen-free conditions. At room temperature, using a Schlenk apparatus under nitrogen purging, 1.512 g (5.6 mmol) of the monomer HBM prepared in Example 1 and 0.38 g (1.4 mmol) of the monomer NB-COOH prepared in Example 3 were added. Then, 50 mL of dried and degassed tetrahydrofuran solvent was added, and the mixture was magnetically stirred for 5 min to obtain a homogeneous solution. Subsequently, 20.64 mg (0.023 mmol) of catalyst (G3) was dissolved in 10 mL of tetrahydrofuran and then rapidly injected into a round-bottom flask. After reacting at room temperature under nitrogen atmosphere for 12 h, 1 mL of vinyl ether was added to terminate the reaction, and the mixture was stirred for 30 min. The polymer solution was added dropwise to 600 mL of anhydrous methanol. After filtration, washing, and vacuum drying, the product was dissolved again in tetrahydrofuran, adsorbed by an adsorbent, filtered, washed, and the filter residue was collected. The collected product was then vacuum dried at 40 °C for 16 h to obtain the cyclic olefin copolymer, which was then subjected to further characterization.

[0054] The cyclic olefin copolymer obtained in this embodiment has a glass transition temperature of ( ). T g The temperature was 191.36 °C. High-temperature GPC analysis showed a weight-average molecular weight of 5.91 × 10⁻⁶. 4 The copolymer has a g / mol content and a narrow molecular weight distribution (PDI = 1.85). It has a refractive index of 1.582, an Abbe number of 34.44, and a transmittance of over 95% at 589 nm. Specific copolymer data are shown in Table 1.

[0055] Example 8 The structural formula of the cyclic olefin copolymer (HBM / M4) is as follows: x=400, y=100 The synthesis steps are as follows: Ring-opening metathesis polymerization was carried out using Grubbs III as a catalyst, and all polymerization reactions were conducted under anhydrous and oxygen-free conditions. At room temperature, using a Schlenk apparatus under nitrogen purging, 1.512 g (5.6 mmol) of the monomer HBM prepared in Example 1 and 0.374 mL (1.4 mmol) of the monomer TESNB prepared in Example 4 were added. Then, 50 mL of dried and degassed tetrahydrofuran solvent was added, and the mixture was magnetically stirred for 5 min to obtain a homogeneous solution. Subsequently, 20.64 mg (0.023 mmol) of catalyst (G3) was dissolved in 10 mL of tetrahydrofuran and then rapidly injected into a round-bottom flask. After reacting at room temperature under nitrogen atmosphere for 12 h, 1 mL of vinyl ether was added to terminate the reaction, and the mixture was stirred for 30 min. The polymer solution was added dropwise to 600 mL of anhydrous methanol. After filtration, washing, and vacuum drying, the product was dissolved again in tetrahydrofuran, adsorbed by an adsorbent, filtered, washed, and the filter residue was collected. The collected product was then vacuum dried at 40 °C for 16 h to obtain the cyclic olefin copolymer, which was then subjected to further characterization.

[0056] The cyclic olefin copolymer obtained in this embodiment has a glass transition temperature of ( ). T g The temperature was 174.72 °C. High-temperature GPC analysis showed a weight-average molecular weight of 4.53 × 10⁻⁶. 4 The copolymer has a g / mol content and a narrow molecular weight distribution (PDI = 1.73). It has a refractive index of 1.561, an Abbe number of 34.75, and a transmittance of over 95% at 589 nm. Specific copolymer data are shown in Table 1.

[0057] Example 9 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M1-Ti10) with a titanium dioxide particle weight fraction of 10 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NBMO from Example 5 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and stirring was continued for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 0.476 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe, and stirring was continued for 2 h at room temperature. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0058] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 175.41 ℃. The refractive index is 1.589, the Abbe number is 37.01, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0059] Example 10 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M1-Ti20) with a titanium dioxide particle weight fraction of 20 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NBMO from Example 5 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.068 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for further characterization.

[0060] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 178.49 ℃. The refractive index is 1.605, the Abbe number is 36.26, and the transmittance of the composite material at 589 nm is over 90% (thickness is 400~600 nm).

[0061] Example 11 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M1-Ti30) with a titanium dioxide particle weight fraction of 30 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NBMO from Example 5 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.832 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for further characterization.

[0062] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 180.09 ℃. The refractive index is 1.634, the Abbe number is 38.09, and the transmittance of the composite material at 589 nm is over 90% (thickness is 400~600 nm).

[0063] Example 12 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M1-Ti40) with a titanium dioxide particle weight fraction of 40 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NBMO from Example 5 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 2.842 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane and drop-coated onto a glass substrate. The substrate was then vacuum-dried at 80 °C for 6 h to obtain a composite film, which was then subjected to further characterization.

[0064] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 183.68 ℃. The refractive index is 1.664, the Abbe number is 33.02, and the transmittance of the composite material at 589 nm is over 90% (thickness is 400~600 nm).

[0065] Example 13 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M2-Ti10) with a titanium dioxide particle weight fraction of 10 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-OH from Example 6 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 0.476 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0066] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 195.50 ℃. The refractive index is 1.597, the Abbe number is 26.11, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0067] Example 14 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M2-Ti20) with a titanium dioxide particle weight fraction of 20 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-OH from Example 6 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.068 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane and drop-coated onto a glass substrate. The substrate was then vacuum-dried at 80 °C for 6 h to obtain a composite film, which was then subjected to further characterization.

[0068] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 202.48 ℃. The refractive index is 1.613, the Abbe number is 33.30, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0069] Example 15 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M2-Ti30) with a titanium dioxide particle weight fraction of 30 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-OH from Example 6 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.832 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0070] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 211.96 ℃. The refractive index is 1.649, the Abbe number is 33.74, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0071] Example 16 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M2-Ti40) with a titanium dioxide particle weight fraction of 40 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-OH from Example 6 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and stirring was continued for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 2.842 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe, and stirring was continued for 2 h at room temperature. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film, which was then subjected to further characterization.

[0072] The composite material obtained in this embodiment has a glass transition temperature of ( ). T gThe temperature is 217.09 ℃. The refractive index is 1.701, the Abbe number is 30.63, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0073] Example 17 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M3-Ti10) with a titanium dioxide particle weight fraction of 10 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-COOH from Example 7 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and stirring was continued for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 0.476 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe, and stirring was continued for 2 h at room temperature. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0074] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 195.59 ℃. The refractive index is 1.594, the Abbe number is 25.98, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0075] Example 18 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M3-Ti20) with a titanium dioxide particle weight fraction of 20 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-COOH from Example 7 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and stirring was continued for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.068 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe, and stirring was continued for 2 h at room temperature. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0076] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 206.72 °C. The refractive index is 1.608, the Abbe number is 26.37, and the transmittance of the composite material at 589 nm is over 95% (thickness is 400~600 nm).

[0077] Example 19 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M3-Ti30) with a titanium dioxide particle weight fraction of 30 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-COOH from Example 7 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.832 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0078] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 213.34 ℃. The refractive index is 1.643, the Abbe number is 28.09, and the transmittance of the composite material at 589 nm is over 90% (thickness is 400~600 nm).

[0079] Example 20 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M3-Ti40) with a titanium dioxide particle weight fraction of 40 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NB-COOH from Example 7 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 2.842 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for further characterization.

[0080] The composite material obtained in this embodiment has a glass transition temperature of ( ). T g The temperature is 218.43 ℃. The refractive index is 1.697, the Abbe number is 29.45, and the transmittance of the composite material at 589 nm is over 90% (thickness is 400~600 nm).

[0081] Example 21 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M4-Ti10) with a titanium dioxide particle weight fraction of 10 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / TESNB from Example 8 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and stirring was continued for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 0.476 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe, and stirring was continued for 2 h at room temperature. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0082] The composite material obtained in this embodiment did not have a detected glass transition temperature. It has a refractive index of 1.614, an Abbe number of 32.03, and a transmittance of over 95% at 589 nm (thickness 400-600 nm).

[0083] Example 22 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M4-Ti20) with a titanium dioxide particle weight fraction of 20 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / TESNB from Example 8 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and stirring was continued for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.068 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe, and stirring was continued for 2 h at room temperature. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for subsequent characterization.

[0084] The composite material obtained in this embodiment did not have a detected glass transition temperature. It has a refractive index of 1.635, an Abbe number of 26.07, and a transmittance of over 95% at 589 nm (thickness 400-600 nm).

[0085] Example 23 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M4-Ti30) with a titanium dioxide particle weight fraction of 30 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / TESNB from Example 8 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 1.832 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film, which was then subjected to further characterization.

[0086] The composite material obtained in this embodiment did not have a detected glass transition temperature. It has a refractive index of 1.645, an Abbe number of 33.85, and a transmittance of over 95% at 589 nm (thickness 400-600 nm).

[0087] Example 24 The structural formula of the titanium dioxide / cyclic olefin copolymer composite material is: x=400, y=100 The steps for synthesizing a polymer (HBM / M4-Ti40) with a titanium dioxide particle weight fraction of 40 wt% are as follows: At room temperature, 0.05 g of the cyclic olefin copolymer HBM / TESNB from Example 8 was dissolved in 2 mL of dioxane. 0.1 mL of hydrochloric acid was added very slowly to the polymer solution, and the mixture was stirred for 30 min at room temperature. 0.5 mL of Ti(OBu)4 was dissolved in 9.5 mL of dioxane, and 2.842 mL of the above tetrabutyl titanate dioxane solution was added dropwise to the cyclic olefin copolymer solution using a syringe. The mixture was stirred at room temperature for 2 h. Finally, the resulting precursor solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane, drop-coated onto a glass substrate, and vacuum dried at 80 °C for 6 h to obtain a composite film for further characterization.

[0088] The composite material obtained in this embodiment did not have a detected glass transition temperature. It has a refractive index of 1.665, an Abbe number of 30.03, and a transmittance of over 90% at 589 nm (thickness 400-600 nm).

[0089] Table 1. Performance data of copolymers of HBM with norbornene derivatives containing functional reactive sites. a

[0090] a Reaction conditions: Cat. = 23.3 μmol, [HBM + norbornene derivative] / Cat. = 300, total polymerization volume 60 mL, temperature = 25 ℃; b The ratio of M1 to norbornyl derivatives; c High-temperature GPC testing revealed; d DSC test results.

[0091] A comparison of Example 6 and Example 16 shows that the titanium dioxide / cyclic olefin copolymer composite material prepared by introducing titanium dioxide in this invention achieves a comprehensive improvement in both optical and thermal properties compared to pure cyclic olefin copolymers. The polymer refractive index of Example 16 is as high as 1.701, an increase of 0.12 compared to 1.585 in Example 6, making it more suitable for the field of high refractive index optical materials. Furthermore, the glass transition temperature of Example 16 (…) T gThe temperature reached 217.09 °C, a significant increase from 191.70 °C in Example 6, indicating that the introduction of titanium dioxide particles also significantly improved the thermal stability of the material. Simultaneously, while introducing nanoparticles to increase the refractive index of the material, this invention still maintained excellent transparency (light transmittance at 589 nm >95%). These combined properties far surpass those of Example 6.

[0092] Figure 1 and Figure 2 The NMR spectra of the cycloolefin monomer NB-OH obtained in Example 2 of this invention are respectively. 1 H-NMR spectrum and 13 C-NMR spectrum; by Figure 1 and Figure 2 As can be seen, the characteristic peaks are consistent with the expected structure, proving that the cyclic olefin monomer NB-OH was successfully prepared.

[0093] Figure 3 and Figure 4 The NMR spectra of the cyclic olefin copolymers obtained in Example 6 of this invention are respectively... 1 H-NMR spectrum and 13 C-NMR spectrum; by Figure 3 and Figure 4 It can be seen that the characteristic peaks of the cyclic olefin copolymer are consistent with the expected structure, proving that the cyclic olefin copolymer was successfully prepared.

[0094] Figure 5 and Figure 6 The differential scanning calorimetry curves of the materials obtained in Examples 6 and 16 of the present invention are shown respectively (in the figures, experimental examples represent embodiments, the same below); by Figure 5 It can be seen that the cyclic olefin copolymer prepared in Example 6 has a glass transition temperature as high as 191.70 °C and exhibits high thermal stability. After introducing titanium dioxide particles, the glass transition temperature of the composite material is further increased by 25.39 °C.

[0095] Figure 7 and Figure 8 The refractive index curves of the materials obtained in Examples 6 and 16 of the present invention are shown respectively; the polymer in Example 16 has a high refractive index of up to 1.701 in the visible light range.

[0096] Figure 9 and Figure 10 The transmittance curves of the materials obtained in Examples 6 and 16 of the present invention are shown respectively. Even with the introduction of 40 wt% nanoparticles, the composite material prepared in Example 16 still has a visible light transmittance of more than 95% at 589 nm, exhibiting high transparency.

[0097] Figure 11The water contact angle diagrams are for the composite materials obtained in Examples 6, 14, and 16 of this invention; (The remaining text appears to be a fragmented and incomplete sentence, possibly due to OCR errors.) Figure 11 It can be seen that Experiment 6 is a pure polymer film with an initial water contact angle of 85.44°, exhibiting hydrophobicity. The water contact angle of Experiment 14 is 71.96°, and that of Experiment 16 is 54.83°. The surface wettability of the material is affected by the titanium dioxide particles. It can be observed that as the weight fraction of titanium dioxide particles increases, the water contact angle on the material surface decreases. Water can spread into a uniform water film on its surface rather than discrete water droplets, exhibiting obvious hydrophilic properties.

[0098] Figures 5 to 11 All experimental examples in this document represent implementation examples.

[0099] Comparative Examples 1-4 are titanium dioxide / cyclic olefin polymer composites prepared by physical blending. The cyclic olefin copolymer used was the polymer (HBM / M1) from Example 5. At room temperature, 0.05 g of the cyclic olefin copolymer HBM / NBMO from Example 5 was dissolved in 2 mL of dioxane. After complete dissolution, titanium dioxide powder with a particle size of 5-10 nm was added to the polymer solution. Different polymer-to-titanium dioxide ratios, namely 90:10, 80:20, 70:30, and 60:40, corresponded to Examples 1-4, and were stirred at room temperature for 2 h. Finally, the resulting solution was filtered through a 0.45 μm polytetrafluoroethylene filter membrane and drop-coated onto a glass substrate. The substrate was then vacuum-dried at 80 ℃ for 6 h to obtain the composite film, which was then subjected to further characterization. See Table 2 for details.

[0100] Table 2 Properties of titanium dioxide / cycloolefin copolymer composites prepared by physical blending method

[0101] A comparison of Comparative Examples 1-4 and Examples 5 and 9-12 shows that the titanium dioxide / cyclic olefin polymer composite material of the present invention exhibits superior optical properties. The titanium dioxide / cyclic olefin polymer composite material prepared by blending method shows a significant decrease in transmittance and only a slight increase in refractive index. In contrast, the composite material of the present invention maintains high refractive index while possessing high transmittance. By introducing titanium dioxide particles into the polymer matrix, the present invention significantly improves the refractive index and glass transition temperature of the material while maintaining its excellent transmittance, providing important technical support for the preparation of high-refractive-index cyclic olefin polymers with potential optical applications.

[0102] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing a high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material, characterized in that, Includes the following steps: Step 1: Under anhydrous and oxygen-free conditions, the monomer HBM and the norbornene derivative containing functional reaction sites are dissolved in a solvent, a catalyst is added to carry out the reaction, and the reaction is terminated to obtain a cyclic olefin copolymer. Step 2: Dissolve the cyclic olefin copolymer in a solvent, add tetrabutyl titanate to carry out a hydrolysis-condensation reaction, and obtain a high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material. The structural formula of the monomer HBM is shown below: ； The structural formula of norbornene derivatives containing functional reaction sites is at least one of the following structural formulas M1 to M4: 。 2. The preparation method according to claim 1, characterized in that, In step 1, the molar ratio of monomer HBM to norbornene derivative containing functional reaction sites is 4:

1.

3. The preparation method according to claim 1, characterized in that, In step 1, the reaction conditions are set as follows: temperature is room temperature to 80 ℃, and time is 6 to 24 h.

4. The preparation method according to claim 1, characterized in that, In step 1, the monomer HBM is prepared by reacting bicyclic [2.2.1]hept-2,5-diene with anthracene.

5. The preparation method according to claim 1, characterized in that, The structural formula of the cyclic olefin copolymer is shown below: In the formula, x and y are the degree of polymerization, 0 ≤ x ≤ 900, 0 ≤ y ≤ 800, but do not represent block copolymers.

6. The preparation method according to claim 1, characterized in that, In step 2, the solvent is a cyclic ether compound; the ratio of cyclic olefin copolymer to tetrabutyl titanate is 1 g : (0.4~3) mL.

7. The preparation method according to claim 1, characterized in that, In step 2, the conditions for the hydrolysis-condensation reaction are set as follows: reaction at room temperature for 1-4 hours.

8. A high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material prepared by the preparation method according to any one of claims 1 to 7.

9. The high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material according to claim 8, characterized in that, The structural formula of the high-refractive-index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material is shown below: In the formula, x and y are the degree of polymerization, 0 ≤ x ≤ 900, 0 ≤ y ≤ 800, but do not represent block copolymers.

10. The application of the high refractive index, colorless and transparent titanium dioxide / cyclic olefin copolymer composite material as described in claim 8 in the preparation of optical materials.

Images