Preparation method of norbornene-based polymer material with high dielectric constant and high refractive index

Abstract

The invention discloses a preparation method of a norbornene-based polymer material with high dielectric constant and high refractive index. The structural formula of the polymer is shown as a formula I. According to the invention, several norbornene functional monomers are designed and synthesized by a'functional monomer-polymerization 'method, a series of polymers of which the main chain is formed by alternately connecting alicyclic rings and double bonds and the side group is bonded with a methylsulfonyl functional group for enhancing polarization and a benzocyclobutene group capable of thermally opening a ring are prepared by ring-opening metathesis polymerization (ROMP), and the polymer is subjected to thermocuring, so that the polymer is prepared. The linear polymers can be completely crosslinked to form a net structure with higher thermal stability and high insulating property. In the frequency range of 101-106 Hz, the material shows stable high dielectric constant (the dielectric constant is 2.8-4.2) and low dielectric loss factor (the dielectric loss is 4 * 10 <-4 >). In addition, the novel material disclosed by the invention shows excellent comprehensive performance in multiple aspects, including excellent thermal stability (thermal decomposition temperature Td5% gt; 400 DEG C), high refractive index (about 1.7) and excellent mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a series of post-crosslinkable high dielectric and high refractive index norbornene-based polymers synthesis and curing methods. Background Technology

[0002] With the rapid development of integrated circuit technology, the process node of complementary metal-oxide-semiconductor (CMOS) has broken through 45nm. In this process, the physical thickness of the traditional SiO2 gate dielectric is approaching 1nm. Due to the low dielectric constant of SiO2 (k≈3.9), it is necessary to reduce the thickness to improve capacitance; however, when the thickness is below 2nm, the quantum tunneling effect leads to a sharp increase in leakage current, and the risk of breakdown and leakage power consumption constitute the core bottleneck restricting chip performance and energy efficiency. Meanwhile, the development of modern photonic integrated circuits (PIC) relies on utilizing the refractive index difference between different materials to confine light waves within micrometer or nanometer-scale channels through total internal reflection, thereby realizing the transmission, modulation, and processing of optical signals at the chip scale. The high performance of on-chip integrated optical waveguides is highly dependent on the continuous breakthrough of material refractive index. Therefore, developing high-k materials to improve capacitance and reduce equivalent physical thickness, or developing high-refractive-index materials for on-chip integrated optical waveguides, has become a research hotspot in this field.

[0003] Compared to inorganic materials, polymers possess advantages such as high dielectric strength, excellent electrical insulation properties, lightweight, and low manufacturing costs. Their dielectric constant can be controlled at both the molecular and mesoscopic scales: 1) Molecular-scale structural design: introducing polar functional groups (such as cyano, sulfonyl, and bromine) into monomers to enhance orientation polarization, or introducing highly polar segments through copolymerization; 2) Mesoscopic structural control: enhancing polarization by forming nano-ferroelectric domains through annealing or electric field modulation, or enhancing interfacial polarization through microphase separation in block copolymers / blends. However, according to the microscopic polarization mechanism, increasing the dielectric constant often inevitably leads to an increase in dielectric loss, resulting in increased power consumption. Furthermore, electronic polarization depends on the displacement of the electron cloud; enhancing electronic polarization (e.g., promoting electron cloud shift through conjugated structures) reduces the material's band gap, increases intrinsic conductivity, and exacerbates leakage power consumption while reducing insulation performance. On the other hand, introducing chemical groups with high molar refractive index and low molar volume (such as halogen atoms (except fluorine), aromatic rings, sulfur atoms, etc.) into the polymer structure is a common strategy for preparing high refractive index materials. However, such groups (especially aromatic rings and sulfur) may reduce the optical transparency of the material in the visible light range, thus limiting its application range. Summary of the Invention

[0004] The purpose of this invention is to provide a method for synthesizing and curing a functionalized high-dielectric, high-refractive-index norbornene-based polymer, wherein the synthesis employs a "functional monomer-polymerization" method. The benzocyclobutene-functionalized norbornene-based polymer is thermosetting, and the cured material achieves high thermal stability, high dielectric constant, and low dielectric loss without compromising its high refractive index. Furthermore, the insulation properties of the cured polymer are significantly improved.

[0005] On one hand, the present invention provides a benzocyclobutene-functionalized norbornene-based polymer of Formula I:

[0006]

[0007] In Formula I above, R1, R2, and R3 are each independently selected from CH2 or oxygen; R4 represents ortho / meta / para-methanesulfonylphenyl;

[0008] Where x, y, and z represent the degree of aggregation, and y and z are not both 0; the values ​​of x and z range from 0 to 150; and the values ​​of y range from 0 to 300.

[0009] Specifically, when y = 0, the polymer shown in Equation I is a copolymer formed by two monomers;

[0010] When x, y, z ≠ 0, the polymer shown in Equation I is a copolymer formed by three monomers.

[0011] When x = z = 0, the polymer shown in Equation I is a homopolymer.

[0012] The benzocyclobutene-functionalized norbornene-based polymer may specifically be one or more of the following polymers:

[0013] 1) Polymer pre-P150-B0: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 0, z is 150;

[0014] 2) Polymer pre-P150-B60: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 60, z is 90;

[0015] 3) Polymer pre-P150-B150: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 150, z is 0;

[0016] 4) Polymer pre-P50-B250: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 50, y is 250, z is 0;

[0017] 5) Polymer pre-P0-B300: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 0, y is 300, z is 0.

[0018] In a second aspect, the present invention provides a method for preparing a polymer as described in the first aspect of the present invention, comprising the following steps:

[0019] 1) Cis-5-norbornene-ex-2,3-dicarboxylic anhydride reacts with 2,3 or 4-methanesulfonyl aniline in the presence of catalyst I to obtain methanesulfonyl norbornene monomer;

[0020] The structural formula of the cis-5-norbornene-ex-2,3-dicarboxylic anhydride is as follows:

[0021] The structural formula of the 2,3 or 4-methanesulfonyl aniline is as follows:

[0022] The structural formula of the obtained methanesulfonyl norbornene monomer is as follows:

[0023] 2) 4-Bromobenzocyclobutene reacts with ammonia in the presence of catalyst II to give 4-aminobenzocyclobutene; further, 4-aminobenzocyclobutene reacts with cis-5-norbornene-ex-2,3-dicarboxylic anhydride in the presence of catalyst I to give benzocyclobutene norbornene monomer.

[0024] The structural formula of the 4-bromobenzocyclobutene is as follows:

[0025] The structural formula of the 4-aminobenzocyclobutene is as follows:

[0026] The structural formula of the benzocyclobutene norbornene monomer is as follows:

[0027] 3) Aniline reacts with cis-5-norbornene-ex-2,3-dicarboxylic anhydride under the action of catalyst I to undergo an imidization reaction to obtain norbornene monomer;

[0028] The structural formula of the aniline is:

[0029] The structural formula of the norbornene monomer is as follows:

[0030] 4) The methanesulfonyl norbornene monomer, benzocyclobutene norbornene monomer and norbornene monomer undergo ROMP polymerization reaction under the action of catalyst III to obtain the linear benzocyclobutene-functionalized norbornene polymer shown in Formula I.

[0031] In step 1) of the above preparation method, the molar ratio of cis-5-norbornene-ex-2,3-dicarboxylic anhydride to methanesulfonyl aniline is 1-2:1, specifically 1.49:1;

[0032] The catalyst I is one or more selected from triethylamine, 4-dimethylaminopyridine, 4-pyrrolidinylpyridine and 1,8-diazabicycloundec-7-ene;

[0033] The feed ratio of catalyst I to methanesulfonyl aniline is 0.2-10 mmol:1 mmol.

[0034] The conditions for the imidization reaction are: temperature 110-130℃ and time 22-24h.

[0035] In step 2) of the above preparation method, the molar ratio of 4-bromobenzocyclobutene to ammonia is 1:10-300 (specifically, it can be 1:10-30).

[0036] The catalyst II is one or more of CuI, CuBr, Cu2O, and Cu;

[0037] The molar ratio of catalyst II to 4-bromobenzocyclobutene is 1:1-30, specifically 1:5;

[0038] The conditions for the substitution reaction are: temperature 90-110℃, time 48-72h;

[0039] The molar ratio of 4-aminobenzocyclobutene to cis-5-norbornene-exo-2,3-dicarboxylic anhydride is 1:1-2;

[0040] The conditions for the imidization reaction are: temperature 110-130℃, time 1-3h.

[0041] In step 3) of the above preparation method, the molar ratio of cis-5-norbornene-ex-2,3-dicarboxylic anhydride to aniline is 1-2:1;

[0042] The feed ratio of catalyst I to aniline is 0.2-10 mmol:1 mmol.

[0043] The conditions for the imidization reaction are: temperature 110-130℃, time 1-4h.

[0044] In step 4) of the above preparation method, the catalyst III is a Grubbs catalyst;

[0045] The molar ratio of catalyst III to the total of the three functional monomers is 1:100-400, specifically 1:300;

[0046] The ROMP polymerization reaction is carried out in organic solvent I, which is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, toluene, and dichloromethane.

[0047] The conditions for the ROMP polymerization reaction are: temperature 20-40℃, time 1-24h.

[0048] Thirdly, the present invention provides a benzocyclobutene-functionalized norbornene-based polymer cured product, the structure of which is shown in Formula II:

[0049]

[0050] In Equation II above, R1, R2, R3, and R4 are defined in the same way as in Equation I;

[0051] The benzocyclobutene-functionalized norbornene-based polymer cured product may specifically be one or more of the following cured products:

[0052] 1) Cured product P150-B0: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 0, z is 150;

[0053] 2) Cured product P150-B60: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 60, z is 90;

[0054] 3) Cured product P150-B150: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 150, z is 0;

[0055] 4) Cured product P50-B250: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 50, y is 250, z is 0;

[0056] 5) Cured product P0-B300: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 0, y is 300, z is 0.

[0057] The above-mentioned benzocyclobutene-functionalized norbornene-based polymer cured product is obtained by curing the benzocyclobutene-functionalized norbornene-based polymer.

[0058] The curing temperature can be 250-350℃, specifically 300℃, and the curing time can be 1-4 hours, specifically 2 hours.

[0059] The application of the above-mentioned benzocyclobutene-functionalized norbornene-based polymer or its cured product in the preparation of capacitor materials or high-refractive-index materials also falls within the scope of protection of this invention.

[0060] The present invention further provides a capacitor material or a high refractive index material, which is made from the above-mentioned benzocyclobutene-functionalized norbornene-based polymer cured product.

[0061] Compared with the prior art, the present invention has the following beneficial effects:

[0062] This invention utilizes a modular molecular engineering control strategy via a "functional monomer-polymerization" method to design and synthesize several norbornene functional monomers. Through ring-opening metathesis polymerization (ROMP), a series of polymers were prepared with alternating alicyclic and double bonds in the main chain, and side groups bonded with methanesulfonyl functional groups for enhanced polarization and thermally openable benzocyclobutene groups. These polymers are used to manufacture high-performance benzocyclobutene-functionalized, high-dielectric, high-refractive-index norbornene-based materials. Through a programmed thermosetting process, these linear polymers can achieve complete crosslinking, forming a network structure with higher thermal stability and high insulation properties. At 10... 1 -10 6 Within the Hz frequency range, the material of this invention exhibits a stable high dielectric constant (dielectric constant 2.8–4.2) and a low dielectric loss factor (dielectric loss ~4 × 10⁻⁴). 4 Furthermore, the novel material of this invention exhibits excellent comprehensive properties in many aspects, including outstanding thermal stability (thermal decomposition temperature T). d5％ The materials possess properties such as high dielectric constant (>400℃), high refractive index (approximately 1.7), and excellent mechanical properties. The molecular design method provided by this invention paves the way for the development of novel high dielectric constant and high refractive index materials, and demonstrates an effective strategy for optimizing the performance of advanced chip manufacturing and on-chip integrated optical waveguide materials.

[0063] To address the aforementioned challenges, we proposed a modular molecular engineering control strategy, designing and synthesizing several norbornene functional monomers. A series of polymers with alternating alicyclic and double-bonded backbones, side groups for enhanced polarization, and thermally openable benzocyclobutene groups were prepared via ROMP polymerization. The refractive indices of the obtained polymers before and after thermosetting were both approximately 1.7, with k values ​​ranging from 2.8 to 4.2. More importantly, the insulation properties of the cured polymers were significantly improved, potentially solving the leakage current and power consumption problem. Attached Figure Description

[0064] Figure 1 The 1H NMR spectrum of the methanesulfonyl norbornene monomer prepared in Example 1 of this invention;

[0065] Figure 2 The 1H NMR spectrum of the benzocyclobutene norbornene monomer prepared in Example 2 of this invention;

[0066] Figure 3The above is the 1H NMR spectrum of the norbornene monomer prepared in Example 3 of this invention;

[0067] Figure 4 The 1H NMR spectrum of the linear benzocyclobutene-functionalized norbornene polymer prepared in Example 4 of this invention;

[0068] Figure 5 This is a comparative graph showing the dielectric properties of the five cured products prepared in Example 5 of this invention.

[0069] Figure 6 This is a comparison chart of the thermal stability of the five cured products prepared in Example 5 of this invention.

[0070] Figure 7 This is a comparative graph showing the mechanical properties of the five cured products prepared in Example 5 of this invention.

[0071] Figure 8 This is a comparison chart of insulation tests of the five cured products prepared in Example 5 of the present invention. Detailed Implementation

[0072] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0073] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0074] Example 1: Preparation of methanesulfonyl norbornene monomer

[0075] In a 250 mL three-necked flask, cis-5-norbornene-ex-2,3-dicarboxylic anhydride (8.06 g, 49.1 mmol), toluene (110 mL), triethylamine (40 mL), 4-methanesulfonylaniline (5.66 g, 33.0 mmol), and a magnetic stir bar were added sequentially. The mixture was bubbled under nitrogen in an ice bath for 15 min. Under nitrogen protection, the mixture was heated to reflux for 23 h, and the reaction was monitored by TLC. After the system cooled to room temperature, it was filtered. The resulting solid was slurried with ethanol, filtered, and the filter cake was washed with ethanol and dried under vacuum at 90 °C overnight. The resulting white solid was the methanesulfonylnorbornene monomer.

[0076] The 1H NMR spectrum of the methanesulfonyl norbornene monomer prepared in this embodiment is as follows: Figure 1 As shown.

[0077] Example 2: Preparation of benzocyclobutene norbornene monomer

[0078] In a 150 mL glass pressure-resistant flask, 4-bromobenzocyclobutene (6.04 g, 33.0 mmol), cuprous oxide (0.95 g, 6.6 mmol), N-methylpyrrolidone (20 mL), ammonia (25%–28%, 40 mL), and a magnetic stir bar were added sequentially. The flask was bubbled under nitrogen for 15 s in an ice bath and then sealed. The mixture was heated in an oil bath at 100 °C for 48 h. After cooling to room temperature, the mixture was extracted with ethyl acetate / saturated brine. The combined organic phases were dried over anhydrous magnesium sulfate, filtered, and after removing most of the solvent by rotary evaporation, vacuum distillation was performed to obtain a clear liquid (4-aminobenzocyclobutene, bp 95–105 °C / 6 mmHg). In a 250 mL three-necked flask, cis-5-norbornene-ex-2,3-dicarboxylic anhydride (7.75 g, 47.2 mmol), toluene (94 mL), triethylamine (32 mL), the above clear liquid (30 mmol), and a magnetic stir bar were added sequentially. The flask was bubbled under nitrogen for 15 min in an ice bath. Under nitrogen protection, the mixture was heated to reflux for 1.5 h, and the reaction was monitored by TLC. After the system cooled to room temperature, it was filtered. The resulting crude solid product was purified by column chromatography (eluent was pure dichloromethane). After removing the solvent by rotation, it was dried under vacuum at 70 °C overnight to obtain a white solid, which was the benzocyclobutene norbornene monomer.

[0079] The 1H NMR spectrum of the benzocyclobutene norbornene monomers prepared in this embodiment is shown below. Figure 2 As shown.

[0080] Example 3: Preparation of norbornene monomer

[0081] In a 1000 mL three-necked flask, cis-5-norbornene-ex-2,3-dicarboxylic anhydride (34.87 g, 212.4 mmol), toluene (480 mL), triethylamine (170 mL), aniline (16.48 g, 177 mmol), and a magnetic stir bar were added sequentially. The mixture was bubbled under nitrogen in an ice bath for 15 min. Under nitrogen protection, the mixture was heated to reflux for 3 h, and the reaction was monitored by TLC. After the system cooled to room temperature, it was filtered. The resulting solid was slurried with ethanol, filtered, and the filter cake was washed with ethanol and dried under vacuum at 90 °C overnight to obtain a white solid, which was the norbornene monomer.

[0082] The 1H NMR spectrum of the norbornene monomer obtained in this embodiment is as follows: Figure 3 As shown.

[0083] Example 4: Preparation of linear benzocyclobutene-functionalized norbornene-based polymers

[0084] In a glove box, Grubbs catalyst ([1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinedimethyl]dichloro(phenylmethylene)bis(3-bromopyridine)ruthenium(II), 95%), methanesulfonyl norbornene monomer, benzocyclobutene norbornene monomer and norbornene monomer were dissolved in N,N-dimethylformamide (the molar ratio of Grubbs catalyst to the total of the three functional monomers was 1:300) at a certain molar ratio to achieve a concentration of 1 mmol / 10 mL (DMF, 160 mL). After polymerization for 1 h, the mixture was removed from the glove box, poured into a bottle containing 600 mL of ethanol to precipitate, centrifuged, and the supernatant was discarded. The sample was dried under vacuum at 120°C for 48 hours to obtain a white solid, which was named pre-Px-By (x and y are the molar ratios of the corresponding methanesulfonyl norbornene monomer and benzocyclobutene norbornene monomer to the catalyst, respectively).

[0085] The 1H NMR spectrum of the linear benzocyclobutene-functionalized norbornene polymer pre-P150-B0 prepared in this embodiment is shown below. Figure 4 As shown.

[0086] Example 5: Preparation of Benzocyclobutene-functionalized norbornene-based polymer cured product

[0087] The polymer obtained in Example 4 was prepared into a 20 wt% N,N-dimethylacetamide (DMAc) solution, coated by scraping, pre-baked at 50°C, and after removing most of the solvent, cured at 300°C for 2 hours in a nitrogen atmosphere; the cured benzocyclobutene-functionalized norbornene polymers were Px-By (x and y are the molar ratios of methanesulfonyl norbornene monomer and benzocyclobutene norbornene monomer relative to the catalyst in Example 4).

[0088] The dielectric and thermodynamic properties of the five high-performance benzocyclobutene-functionalized norbornene-based polymer cured products obtained in Example 5 were tested using the following methods:

[0089] The method for testing dielectric properties is: dielectric constant tester method.

[0090] The mechanical properties are tested using a nanoindentation tester.

[0091] The test method for thermal properties is the thermogravimetric analysis method.

[0092] The test method for insulation performance is the breakdown strength tester method.

[0093] The method for testing refractive index is the Abbe refractometer method.

[0094] Table 1 compares the dielectric, mechanical, thermal, and insulating properties of different cured products. Table 2 compares the refractive index data of the five polymers and five cured products prepared in Examples 4 and 5 of this invention. Figure 5 This is a comparison chart of dielectric properties of different cured materials. Figure 6 This is a comparison chart of the thermal stability tests of different cured materials. Figure 7 This is a comparison chart of the mechanical properties of different cured materials. Figure 8 This is a comparison chart of the insulation performance tests of different cured materials.

[0095] Table 1 Comparison of dielectric, mechanical, and thermal properties of different cured products

[0096]

[0097] Table 2 Comparison of refractive index data of different polymers and cured products

[0098]

[0099] The test results above show that:

[0100] (1) Dielectric properties: as shown in Table 1 and Figure 5 As shown, at low frequencies 10-10 6 Within the Hz range, the dielectric constants of the five cured products range from 2.8 to 4.2, with low dielectric loss factors. In particular, the dielectric constants of P150-B0, P150-B60, and P150-B150 are greater than or close to 4, while the dielectric loss factor of P0-B300 is as low as 0.00036. Therefore, the cured products prepared by this invention possess superior high dielectric properties.

[0101] (2) Mechanical properties: as shown in Table 1 and Figure 7 As shown, under room temperature conditions, the storage modulus of the five cured products is higher than 4.2 GPa, especially that of P50-B250 and P0-B300, which have storage moduli as high as 5.80 GPa and 6.14 GPa, respectively. Therefore, the cured products prepared by this invention possess excellent mechanical properties.

[0102] (3) Thermal properties: as shown in Table 1 and Figure 6 As shown, the thermal decomposition temperature of the five cured products is at least 415.5℃, especially that of PO-B300, which has a thermal decomposition temperature as high as 453.9℃. Therefore, it can be seen that the cured products obtained by the present invention have stable thermal properties.

[0103] (4) Insulation performance: such as Figure 8 As shown, the breakdown strength of all five cured products is higher than 600 MV / m, especially the breakdown strength of P0-B300, which is as high as 743 MV / m. Therefore, the cured products prepared by this invention have good insulation properties.

[0104] (5) Refractive index: As shown in Table 2, the refractive indices of the five polymers and the five cured products are all around 1.7. In particular, the refractive indices of P150-B150 and pre-P150-B150 are 1.710. It can be seen that the cured products prepared by the present invention have high refractive indices.

[0105] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. The benzocyclobutene-functionalized norbornene-based polymer shown in Formula I: In Formula I, R1, R2, and R3 are each independently selected from CH2 or oxygen; R4 represents ortho / meta / para-methanesulfonylphenyl; Where x, y, and z represent the degree of aggregation, and y and z are not both 0; the values ​​of x and z range from 0 to 150; and the values ​​of y range from 0 to 300.

2. The polymer according to claim 1, characterized in that, The benzocyclobutene-functionalized norbornene-based polymer is any one or more of the following polymers: 1) Polymer pre-P150-B0: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 0, z is 150; 2) Polymer pre-P150-B60: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 60, z is 90; 3) Polymer pre-P150-B150: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 150, z is 0; 4) Polymer pre-P50-B250: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 50, y is 250, z is 0; 5) Polymer pre-P0-B300: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 0, y is 300, z is 0.

3. A method for preparing the polymer of claim 1 or 2, comprising the following steps: 1) cis-5-norbornene-ex-2,3-dicarboxylic anhydride and 2,3 or 4-methanesulfonyl aniline undergo an imidization reaction in the presence of catalyst I to obtain methanesulfonyl norbornene monomer; The structural formula of the cis-5-norbornene-ex-2,3-dicarboxylic anhydride is as follows: The structural formula of the 2,3 or 4-methanesulfonyl aniline is as follows: The structural formula of the obtained methanesulfonyl norbornene monomer is as follows: 2) 4-Bromobenzocyclobutene reacts with ammonia in the presence of catalyst II to give 4-aminobenzocyclobutene; further, 4-aminobenzocyclobutene reacts with cis-5-norbornene-ex-2,3-dicarboxylic anhydride in the presence of catalyst I to give benzocyclobutene norbornene monomer. The structural formula of the 4-bromobenzocyclobutene is as follows: The structural formula of the 4-aminobenzocyclobutene is as follows: The structural formula of the benzocyclobutene norbornene monomer is as follows: 3) Aniline reacts with cis-5-norbornene-ex-2,3-dicarboxylic anhydride under the action of catalyst I to undergo an imidization reaction to obtain norbornene monomer; The structural formula of the aniline is: The structural formula of the norbornene monomer is as follows: 4) The methanesulfonyl norbornene monomer, benzocyclobutene norbornene monomer and norbornene monomer undergo ROMP polymerization reaction under the action of catalyst III to obtain the linear benzocyclobutene-functionalized norbornene polymer shown in Formula I.

4. The method according to claim 3, characterized in that, In step 1), the molar ratio of cis-5-norbornene-ex-2,3-dicarboxylic anhydride to methanesulfonyl aniline is 1-2:1; The catalyst I is one or more selected from triethylamine, 4-dimethylaminopyridine, 4-pyrrolidinylpyridine and 1,8-diazabicycloundec-7-ene; The feed ratio of catalyst I to methanesulfonyl aniline is 0.2-10 mmol: 1 mmol; The conditions for the imidization reaction are: temperature 110-130℃, time 22-24h; In step 2), the molar ratio of 4-bromobenzocyclobutene to ammonia is 1:10-300; The catalyst II is one or more of CuI, CuBr, Cu2O, and Cu; The molar ratio of catalyst II to 4-bromobenzocyclobutene is 1:1-30; The conditions for the substitution reaction are: temperature 90-110℃, time 48-72h; The molar ratio of 4-aminobenzocyclobutene to cis-5-norbornene-exo-2,3-dicarboxylic anhydride is 1:1-2; The conditions for the imidization reaction are: temperature 110-130℃, time 1-3h; In step 3), the molar ratio of cis-5-norbornene-ex-2,3-dicarboxylic anhydride to aniline is 1-2:1; The feed ratio of catalyst I to aniline is 0.2-10 mmol: 1 mmol; The conditions for the imidization reaction are: temperature 110-130℃, time 1-4h; In step 4), the catalyst III is a Grubbs catalyst; The molar ratio of catalyst III to the total of the three functional monomers is 1:100-400; The conditions for the ROMP polymerization reaction are: temperature 20-40℃, time 1-24h.

5. A benzocyclobutene-functionalized norbornene-based polymer cured product, the structural formula of which is shown in Formula II: In Formula II, R1, R2, R3, and R4 have the same definitions as R1, R2, R3, and R4 in Formula I of claim 1.

6. The cured product according to claim 5, characterized in that, The cured product is any one or more of the following cured products: 1) Cured product P150-B0: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 0, z is 150; 2) Cured product P150-B60: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 60, z is 90; 3) Cured product P150-B150: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 150, y is 150, z is 0; 4) Cured product P50-B250: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 50, y is 250, z is 0; 5) Cured product P0-B300: R1, R2, R3 are CH2, R4 is para-methanesulfonylphenyl, x is 0, y is 300, z is 0.

7. A method for preparing the cured product according to claim 5 or 6, comprising the following steps: the benzocyclobutene-functionalized norbornene-based polymer cured product is obtained by curing the benzocyclobutene-functionalized norbornene-based polymer according to claim 1 or 2. in, The curing temperature is 250-350℃, and the time is 1-4 hours.

8. The use of the benzocyclobutene-functionalized norbornene-based polymer of claim 1 or 2, or the cured product of claim 5 or 6, in the preparation of capacitor materials or high-refractive-index materials.

9. A capacitor material made from the cured material of claim 5 or 6.

10. A high-refractive-index material made from the cured material of claim 5 or 6.

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