Polyimide containing amide bond and benzonorbornane structure and preparation method thereof

Abstract

A polyimide containing an amide bond and a benzonorbornene structure and a preparation method thereof. The present invention starts from a diamine monomer containing a benzonorbornene structure, and efficiently synthesizes a diamine monomer containing an amide bond and a benzonorbornene structure and a polyimide containing an amide bond and a benzonorbornene structure through reactions such as nucleophilic substitution, reduction and a two-step method. Norbornene is used as a side group, which increases the free volume between chain segments, destroys the regular stacking between molecular chains, retains the solubility of the polymer, and ensures the flexibility of the molecular chain without significantly reducing the thermal performance. An amide bond is introduced to increase the interchain force through the formation of hydrogen bonds by the amide group; the high interchain action promotes the close stacking of molecular chains, which is beneficial to enhancing the barrier performance and heat resistance, and has good thermal stability and mechanical properties. The processability of the polyimide is improved, so that it has the characteristics of excellent thermal and mechanical properties, simple synthesis process and low cost, good solubility and excellent product solvent resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and preparation, relates to the field of polyimide materials, and specifically relates to a method for preparing a diamine monomer containing an amide bond and a benzonorbornane structure, a polyimide material, and a preparation method and application thereof. Background Art

[0002] Polyimide (PI) is a type of high-performance material containing an imide ring in the molecular chain. It has excellent thermal and mechanical properties and is widely used in modern high-tech fields. However, due to the rigidity and crystallinity of the main chain of polyimide molecules, such materials have extremely high glass transition temperatures or melting points, are insoluble and difficult to process. In order to solve the poor processing and optical properties of traditional polyimides, in recent years, He Xiaohui and others have studied polyimide materials containing benzonorbornene structures. By introducing ether bonds and non-coplanar norbornene bicyclic structures, a series of results have been achieved. The prepared polyimide has low cost, simple synthesis process, certain solubility, low dielectric constant, etc.

[0003] The molecular structure of a polymer determines its performance. Since there are many types of monomers and they are diverse, monomers with different structures can be selected and combined to adjust the relationship between the molecular structure and performance of polyimide. The synthesis of diamine monomers with new structures has become one of the important methods for preparing good functional polyimides. Benzonorbornane is an important intermediate, which is obtained by isomerization of norbornene and cyclohexenedione and then reduction. Its raw materials for preparation are cheap and easy to obtain, and it is widely used in the field of drug synthesis. The application of its derivatives in materials science, especially engineering plastics, has gradually been valued. The introduction of norbornane heterocycles can retain certain solubility and light transmittance, but the mechanical properties and thermal stability of polyimides prepared with it as raw materials still need to be improved. Summary of the invention

[0004] To solve the above problems, the first object of the present invention is to provide an (aromatic) diamine monomer containing an amide bond and a benzonorbornane structure and a preparation method thereof.

[0005] The second object of the present invention is to provide an (aromatic) polyimide containing an amide bond and a benzonorbornane structure and a preparation method thereof.

[0006] The invention starts from a diamine monomer containing a benzonorbornene structure and efficiently synthesizes a diamine monomer containing an amide bond and a benzonorbornene structure and a polyimide containing an amide bond and a benzonorbornene structure through amidation reaction, reduction and a two-step method.

[0007] The polyimide containing amide bond and benzonorbornane structure prepared by the present invention uses aromatic ether bond as connecting group, which not only ensures the flexibility of molecular chain but also does not significantly reduce thermal performance. Using norbornane bicyclic as side group, it not only destroys the regular stacking between macromolecules, increases the free volume between segments, retains certain solubility of polymer, reduces the dielectric constant of material, ensures certain stacking between macromolecules, and improves the glass transition temperature of polymer. The polyimide provided by the present invention is designed by polymer monomer molecules, introduces diamine monomer containing amide bond structure into polymer composition system, introduces hydrogen bond between macromolecular chains of fully imidized polyimide, so as to enhance the interaction force between macromolecular chains of polyimide, and improve the mechanical strength of polyimide. Introducing amide bond in molecular chain ensures that there is strong hydrogen bonding between polyimide molecular chains, increases the cohesive energy of polyimide, has strong improvement for mechanical properties and can also be copolymerized with various dianhydride monomers to regulate performance.

[0008] The polyimide prepared by the invention has low cost, simple synthesis process, good comprehensive performance, and high mechanical strength and modulus.

[0009] The present invention is achieved through the following technical solutions.

[0010] The diamine monomer containing an amide bond and a benzonorbornane structure of the present invention is a monomer formed by bonding a primary amino group, an aromatic structure, an amide bond, an aromatic ether bond and a benzonorbornane structure, wherein one side of the aromatic ether bond is bonded to the para position of the benzene ring in the benzonorbornane structure, and the other side is bonded to the benzene ring in an aromatic structure, and the other side of the benzene ring of the aromatic structure is bonded to the N atom in the amide bond, and the C atom in the amide bond is bonded to the benzene ring on another aromatic structure, and the structural formula thereof is:

[0011] (Ⅰ)

[0012]

[0013] In the structural formula, Ar1 refers to an aromatic structure bonded to an amide bond and an aromatic ether bond, and Ar2 refers to an aromatic structure bonded to an amide bond and a primary amino group. Here, in order to intuitively and figuratively represent their positions, Ar1 plus a six-membered ring is used to replace the aromatic structure referred to by Ar1, and Ar2 plus a six-membered ring is used to replace the aromatic structure referred to by Ar2;

[0014] Wherein, Ar1 is an aromatic structure:

[0015]

[0016] Ar2 is an aromatic structure:

[0017]

[0018] A polyimide containing an amide bond and a benzonorbornane structure according to the present invention is a polymer formed by bonding a benzonorbornane structure, an aromatic ether bond, an amide bond, an aromatic structure, and an imide structure. Its structural formula is:

[0019]

[0020] In the above structural formula, in the structural formula, Ar1, Ar2, Ar3, and Ar4 represent aromatic structures bonding to an amide group, an aromatic ether bond, and a primary amino group. Here, in order to visually and beautifully represent their positions, the aromatic structures represented by Ar1, Ar2, Ar3, and Ar4 are respectively replaced by Ar1, Ar2, Ar3, and Ar4 plus a six-membered ring;

[0021] n represents the degree of polymerization, which is an integer and n > 0;

[0022] 0 < y ≤ 1. When y = 1, the structural formula (II) represents a polyimide containing an amide bond and a benzonorbornane structure with a homopolymer structure; when 0 < y < 1, the structural formula (II) represents a polyimide containing an amide bond and a benzonorbornane structure with a copolymer structure;

[0023] Among them, Ar1 is an aromatic structure:

[0024]

[0025] Among them, Ar2 is an aromatic structure:

[0026]

[0027] Among them, Ar3 is an aromatic structure:

[0028]

[0029] Among them, Ar4 is an aromatic structure:

[0030]

[0031] A preparation method of a diamine monomer containing an amide bond and a benzonorbornane structure according to the present invention includes the following steps:

[0032] (1) Preparation of a dinitro compound containing an amide bond and a benzonorbornene structure: Under nitrogen conditions, a deacidifying agent is added to an organic solvent solution of a diamine monomer containing a benzonorbornene structure, stirred at room temperature for 0.5 h, and an organic solvent solution of an acyl chloride nitrobenzene compound is added dropwise. Then the system is heated to reflux and stirred for 6 h. The reaction solution is poured into a large amount of water, and a solid is precipitated, filtered, washed, and dried under vacuum to obtain a dinitro compound containing an amide bond and a benzonorbornene structure;

[0033] (2) Preparation of diamine monomers containing amide bonds and benzonorbornene structures: Under nitrogen conditions, anhydrous ethanol solution was added to a dinitro compound containing amide bonds and benzonorbornene structures, and the mixture was stirred at room temperature for 0.5 h. Palladium carbon was then added, and hydrazine hydrate solution was gradually added dropwise. The system was then heated to 80°C and refluxed, stirred for 12 h, cooled, and filtered to remove palladium carbon. The filtrate was poured into a large amount of water, crystallized at low temperature, filtered, washed, and vacuum dried to obtain a diamine monomer containing amide bonds and benzonorbornene structures.

[0034] Furthermore, in the preparation of the dinitro compound described in step (1), the molar ratio of the diamine monomer containing a benzonorbornene structure to the acyl chloride nitrobenzene compound is 1:(1-1.1).

[0035] Furthermore, the organic solvent used in the preparation of the dinitro compound in step (1) is one of N,N-dimethylformamide, N,N-dimethylacetamide or acetonitrile.

[0036] Further, the acyl chloride nitrobenzene compound used in the preparation of the diamine monomer in step (1) is 4-nitrobenzoyl chloride, 2-nitrobenzoyl chloride, m-nitrobenzoyl chloride, 2-methyl-4-nitrobenzoyl chloride, 2-chloro-4-nitrobenzoyl chloride, 2-fluoro-4-nitrobenzoyl chloride, 2,5-difluoro-4-nitrobenzoyl chloride, 2-chloro-5-nitrobenzoyl chloride, 3-nitro-4-methylbenzoyl chloride, 2-methyl-3-nitrobenzoyl chloride, 2-fluoro-5 -nitrobenzoyl chloride, 2,6-dimethyl-3-nitrobenzoyl chloride, 2-chloro-4-fluoro-3-methyl-5-nitrobenzoyl chloride, 2-chloro-4-fluoro-5-nitrobenzoyl chloride, 3-nitro-4-methylamino-benzoyl chloride, 3-methyl-2-nitrobenzoyl chloride, 4-bromo-2-nitrobenzoyl chloride, 2-fluoro-6-nitrobenzoyl chloride, 4-fluoro-2-nitrobenzoyl chloride, 2,4,5-trifluoro-3-methyl-6-nitrobenzoyl chloride.

[0037] Furthermore, in the preparation of the diamine monomer described in step (2), the mass ratio of the dinitro compound containing an amide bond and a benzonorbornene structure, palladium carbon, hydrazine hydrate, and anhydrous ethanol is 1:0.1:4:12.

[0038] The preparation method of a polyimide containing an amide bond and a benzonorbornane structure of the present invention comprises the following steps when the polyimide containing an amide bond and a benzonorbornane structure of a homopolymer structure (y=1) is in the form of a resin:

[0039] Under nitrogen atmosphere and at 5 - 10 °C, dissolve the diamine monomer containing amide bond and benzonorbornane structure in an anhydrous organic solvent. Add an equimolar amount of dianhydride monomer in batches under mechanical stirring. React the reaction system at 10 - 20 °C for 12 h to obtain a polyamic acid solution with a certain viscosity. Then, dropwise add a mixed solution of dehydrating agent and catalyst, continue the reaction for 3 h, and then raise the temperature of the system to 100 °C to promote complete imidization. After the reaction is completed, cool the system to room temperature, then pour it into methanol to obtain a filamentous product. After repeated washing, dry it in a vacuum oven to obtain a polyimide with an amide bond and benzonorbornane structure in the form of a resin homopolymer structure.

[0040] For the preparation method of a polyimide containing an amide bond and a benzonorbornane structure as described in the present invention, when the polyimide with an amide bond and a benzonorbornane structure in the homopolymer structure (y = 1) is in the form of a film, its preparation method includes the following steps:

[0041] Under nitrogen atmosphere and at 5 - 10 °C, dissolve the diamine monomer containing an amide bond and a benzonorbornene structure in an anhydrous organic solvent. Add an equimolar amount of dianhydride monomer in batches under mechanical stirring. React the reaction system at 10 - 20 °C for 12 h to obtain a polyamic acid solution with a certain viscosity. Cast and spread the polyamic acid solution to obtain a wet polyamic acid film, and successively perform solvent removal treatment and thermal imidization. After cooling, peel it off from the glass substrate to obtain a polyimide with an amide bond and a benzonorbornane structure in the form of a film in the homopolymer structure.

[0042] For the preparation method of a polyimide containing an amide bond and a benzonorbornane structure as described in the present invention, when the polyimide with an amide bond and a benzonorbornane structure in the copolymer structure (0 < y < 1) is in the form of a resin, its preparation method includes the following steps:

[0043] Under nitrogen atmosphere and at 5 - 10 °C, dissolve the diamine monomer containing an amide bond and a benzonorbornane structure and other diamine monomers in an anhydrous organic solvent. Add an equimolar amount of dianhydride monomer in batches under mechanical stirring. React the reaction system at 10 - 20 °C for 12 h to obtain a polyamic acid solution with a certain viscosity. Then, dropwise add a mixed solution of dehydrating agent and catalyst, continue the reaction for 3 h, and then raise the temperature of the system to 100 °C to promote complete imidization. After the reaction is completed, cool the system to room temperature, then pour it into methanol to obtain a filamentous product. After repeated washing, dry it in a vacuum oven to obtain a polyimide with an amide bond and a benzonorbornane structure in the form of a resin in the copolymer structure.

[0044] The preparation method of a polyimide containing amide bonds and benzonorbornane structure according to the present invention, when the polyimide containing amide bonds and benzonorbornane structure with a copolymer structure (0 < y < 1) is in the form of a film, its preparation method includes the following steps:

[0045] Under nitrogen conditions and at 5 - 10 °C, dissolve the diamine monomer containing amide bonds and benzonorbornane structure and other diamine monomers in an anhydrous organic solvent, and add an equimolar amount of dianhydride monomer in batches under mechanical stirring. React the reaction system at 10 - 20 °C for 12 h to obtain a polyamic acid solution with a certain viscosity. Cast and spread the polyamic acid solution to obtain a polyamic acid wet film, and perform solvent removal treatment and thermal imidization in sequence. After cooling, peel it off from the glass substrate to obtain a polyimide containing amide bonds and benzonorbornane structure with a copolymer structure in the form of a film.

[0046] Furthermore, the diamine monomer containing amide bonds and benzonorbornane structure is one of all the amide bond diamines prepared above.

[0047] Furthermore, the other diamine monomer is one of 4,4'-diaminodiphenyl ether, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2'-bis(4-aminophenyl)propane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane, 9,9'-bis(4-aminophenyl)fluorene, 4,4'-(1,4-phenylenedioxy)bis(aniline), 1,4'-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl.

[0048] Furthermore, the dianhydride monomer is one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylethertetracarboxylic dianhydride, 2,2',3,3'-diphenylethertetracarboxylic dianhydride, 2,3',3,4'-diphenylethertetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-triphenylbismethylenetetracarboxylic dianhydride.

[0049] Furthermore, the anhydrous organic solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone.

[0050] Further, the solid content of the polyamic acid solution with a certain viscosity is 10 wt% - 15 wt%, and the solid content = the sum of the masses of the added monomers / the sum of the added monomers and the sum of the masses of the anhydrous organic solvents.

[0051] Further, in the preparation of the polyimide containing an amide bond and a benzonorbornane structure in the form of a film, the temperature for solvent treatment is 70 - 90 °C, and the time is 3 - 6 h.

[0052] Further, in the preparation of the polyimide containing an amide bond and a benzonorbornane structure in the form of a film, the heating program for thermal imidization is as follows: keep the temperature at 70 °C for 3 h, then raise the temperature to 100 °C and keep it for 1 h, then raise the temperature to 150 °C and keep it for 1 h; then raise the temperature to 200 °C and keep it for 1 h; then raise the temperature to 250 °C and keep it for 0.5 h; finally raise the temperature to 300 °C and keep it for 0.5 h.

[0053] The beneficial effects of the present invention are as follows: The preparation method of the polyimide containing an amide bond and a benzonorbornane structure proposed by the present invention includes the preparation methods of the polyimide containing an amide bond and a benzonorbornane structure with a homopolymer structure (y = 1) in the form of resin and film, or a copolymer structure (0 < y < 1) containing an amide bond and a benzonorbornane structure. It has a simple preparation process, low production cost, high yield, and the raw materials are cheap and easy to obtain. The reaction conditions are easy to control and have good repeatability. The main chain structure of the polyimide containing an amide bond and a benzonorbornane structure proposed by the present invention is connected by aromatic ether bonds, amide bonds, etc. and benzene rings. While ensuring excellent heat resistance and mechanical strength, it also improves the flexibility of the polyimide macromolecular chain. The norbornane bicyclic structure coupled with the benzene ring has a certain spatial configuration, reducing the close packing and crystallization tendency of the polyimide molecular chain, improving the solubility of the polymer, and making the material have a low dielectric constant; at the same time, it also retains a certain molecular chain packing tendency, increasing the glass transition temperature; through copolymer modification, introducing a third monomer will further broaden the properties of the material and reduce the cost. The preparation methods of the diamine monomer containing an amide bond and a benzonorbornene structure and the polyimide containing an amide bond and a benzonorbornene structure proposed by the present invention can prepare polyimide homopolymers and copolymers with different properties in the form of resin and film. The polyimide prepared by applying the present invention has high thermal stability, low dielectric constant, excellent mechanical properties and certain solubility, and is a high-performance polyimide material with broad application prospects. Description of the Drawings

[0054] Figure 1 It is the nuclear magnetic hydrogen spectrum of the dinitro monomer - 3,6 - bis(4 - (4 - nitrobenzoylamino)phenoxy)benzonorbornene containing an amide bond and a benzonorbornene structure in some embodiments of the present invention.

[0055] Figure 2 This is a hydrogen NMR spectrum of 3,6-bis(4-(4-aminobenzamido)phenoxy)benzonorbornane, a diamine monomer containing an amide bond and a benzonorbornane structure in some embodiments of the present invention.

[0056] Figure 3 The infrared spectra of polyimides containing amide bonds and benzonorbornane structures in the form of resin homopolymer structures and copolymer structures in some embodiments of the present invention.

[0057] Figure 4 The thermogravimetric curves of polyimides containing amide bonds and benzonorbornane structures in the form of thin films of homopolymer structures and copolymer structures in some embodiments of the present invention are shown.

[0058] Figure 5 The tensile stress-strain curves of polyimides containing amide bonds and benzonorbornane structures in the form of thin films and homopolymer structures and copolymer structures in some embodiments of the present invention are shown. DETAILED DESCRIPTION

[0059] The present invention will be further illustrated by the following examples.

[0060] Example 1.

[0061] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0062] Under the conditions of nitrogen and magnetic stirring, 3.56 g (10 mmol) of 3,6-bis (4-aminophenoxy) benzonorbornene and 30 mL of anhydrous N, N-dimethylacetamide were placed in a reaction bottle with a branch, and 5 mL of anhydrous pyridine was added as an acid binding agent. The mixture was stirred at room temperature (25 ° C) for 0.5 h, and 4.08 g (22 mmol) of 4-nitrobenzoyl chloride was dissolved in 30 mL of anhydrous N, N-dimethylacetamide. The anhydrous N, N-dimethylacetamide solution containing 4-nitrobenzoyl chloride was then placed in a constant pressure dropping funnel and slowly added dropwise to the reaction bottle at room temperature. The system was then heated to 80 ° C and refluxed for 6 h. After the reaction was completed, the system was gradually cooled to room temperature. The mixed solution after the reaction was poured into a large amount of distilled water, and the solid was precipitated and collected, filtered, washed, and vacuum dried to obtain 5.88 g of yellow powder, namely 3,6-bis(4-(4-nitrobenzamido)phenoxy)benzonorbornene;

[0063] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0064] Under the conditions of nitrogen and magnetic stirring, 1.308 g (2 mmol) of 3,6-bis(4-(4-nitrobenzamido)phenoxy)benzonorbornene and 50 mL of anhydrous ethanol were placed in a reaction bottle with a branch, stirred at room temperature (25°C) for 0.5 h, and then 0.15 g of palladium carbon (5%) was added, and 20 mL of hydrazine hydrate solution (50%) was gradually added dropwise, and then the system was heated to 80°C and refluxed, and reacted for 12 h. After cooling, it was filtered to remove the palladium carbon, and the filtrate was poured into a large amount of distilled water, crystallized at low temperature, and the precipitate was collected, filtered, washed, and vacuum dried to obtain 1.08 g of white powder, i.e., 3,6-bis(4-(4-aminobenzamido)phenoxy)benzonorbornene.

[0065] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0066] Under nitrogen conditions and 10°C, 0.596g (1mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 4.92mL (4.61g) of anhydrous N,N-dimethylacetamide, and 0.218g (1mmol) of pyromellitic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12h to obtain a polyamic acid solution with a certain viscosity, and then 3mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride to triethylamine was 2:1) was added dropwise. After continuing the reaction for 3h, the system was heated to 100°C to promote complete imidization. After the reaction was completed, the system temperature was lowered to room temperature, and then poured into 20mL of methanol to obtain a filamentous product. After repeated washing, it was dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structure.

[0067] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0068] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 4.92 mL (4.61 g) of anhydrous N, N-dimethylacetamide, and 0.218 g (1 mmol) of pyromellitic dianhydride was added in batches under mechanical stirring to maintain the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 h to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0069] Example 2.

[0070] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0071] Same as Example 1.

[0072] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0073] Same as Example 1.

[0074] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0075] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 5.38 mL (5.05 g) of anhydrous N,N-dimethylacetamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 h to obtain a A polyamic acid solution of a certain viscosity is prepared, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine is 2:1) is added dropwise. After continuing the reaction for 3 hours, the system is heated to 100°C to promote complete imidization. After the reaction is completed, the system temperature is lowered to room temperature and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, the product is dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structures.

[0076] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0077] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 5.38 mL (5.05 g) of anhydrous N, N-dimethylacetamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0078] Example 3.

[0079] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0080] Same as Example 1.

[0081] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0082] Same as Example 1.

[0083] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0084] Under nitrogen conditions and 10°C, 0.596g (1mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 5.48mL (5.14g) of anhydrous N,N-dimethylacetamide, and 0.311g (1mmol) of 4,4'-oxydiphthalic anhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12h to obtain a polyamic acid solution with a certain viscosity, and then 3mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride to triethylamine was 2:1) was added dropwise. After continuing the reaction for 3h, the system was heated to 100°C to promote complete imidization. After the reaction was completed, the system temperature was lowered to room temperature, and then poured into 20mL of methanol to obtain a filamentous product. After repeated washing, it was dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structure.

[0085] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0086] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 5.48 mL (5.14 g) of anhydrous N, N-dimethylacetamide, and 0.311 g (1 mmol) of 4,4'-oxydiphthalic anhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0087] Example 4.

[0088] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0089] Same as Example 1.

[0090] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0091] Same as Example 1.

[0092] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0093] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 6.28 mL (5.89 g) of anhydrous N, N-dimethylacetamide, and 0.444 g (1 mmol) of 4,4'- (hexafluoroisopropylene) diphthalic anhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 h to obtain a A polyamic acid solution of a certain viscosity is prepared, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine is 2:1) is added dropwise. After continuing the reaction for 3 hours, the system is heated to 100°C to promote complete imidization. After the reaction is completed, the system temperature is lowered to room temperature and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, the product is dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structures.

[0094] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0095] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 6.28 mL (5.89 g) of anhydrous N, N-dimethylacetamide, and 0.444 g (1 mmol) of 4,4'- (hexafluoroisopropylene) diphthalic anhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0096] Example 5.

[0097] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0098] Under the conditions of nitrogen and magnetic stirring, 3.56 g (10 mmol) of 3,6-bis (4-aminophenoxy) benzonorbornene and 30 mL of anhydrous N, N-dimethylformamide were placed in a reaction bottle with a branch, and 5 mL of anhydrous pyridine was added as an acid binding agent. The mixture was stirred at room temperature (25 ° C) for 0.5 h, and 4.08 g (22 mmol) of 4-nitrobenzoyl chloride was dissolved in 30 mL of anhydrous N, N-dimethylformamide. The anhydrous N, N-dimethylformamide solution containing 4-nitrobenzoyl chloride was then placed in a constant pressure dropping funnel and slowly added dropwise to the reaction bottle at room temperature. The system was then heated to 80 ° C and refluxed for 6 h. After the reaction was completed, the system was gradually cooled to room temperature. The mixed solution after the reaction was poured into a large amount of distilled water, and the solid was precipitated and collected, filtered, washed, and vacuum dried to obtain 5.88 g of yellow powder, namely 3,6-bis(4-(4-nitrobenzamido)phenoxy)benzonorbornene;

[0099] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0100] Same as Example 1.

[0101] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0102] Same as Example 2.

[0103] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0104] Same as Example 2.

[0105] Example 6.

[0106] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0107] Same as Example 5.

[0108] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0109] Same as Example 1.

[0110] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0111] Same as Example 4.

[0112] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0113] Same as Example 4.

[0114] Example 7.

[0115] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0116] Under the conditions of nitrogen and magnetic stirring, take 3.56g (10mmol) 3,6-bis (4-aminophenoxy) benzonorbornene and 35mL anhydrous acetonitrile in a reaction bottle with a branch, then add 5mL anhydrous pyridine as an acid binding agent, stir at room temperature (25℃) for 0.5h, then take 4.08g (22mmol) 4-nitrobenzoyl chloride and dissolve it in 35mL anhydrous acetonitrile, then place the anhydrous acetonitrile solution containing 4-nitrobenzoyl chloride in a constant pressure dropping funnel, slowly add it dropwise to the reaction bottle at room temperature, then heat the system to 80℃ and reflux, and react for 6h, and gradually cool the system to room temperature after the reaction is completed. Pour the mixed solution after the reaction into a large amount of distilled water, let it stand to precipitate solids and collect the precipitate, filter, wash, and vacuum dry to obtain 5.88g yellow powder, i.e. 3,6-bis (4- (4-nitrobenzylamino) phenoxy) benzonorbornene;

[0117] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0118] Same as Example 1.

[0119] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0120] Same as Example 2.

[0121] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0122] Same as Example 2.

[0123] Example 8.

[0124] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0125] Same as Example 7.

[0126] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0127] Same as Example 1.

[0128] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0129] Same as Example 4.

[0130] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0131] Same as Example 4.

[0132] Example 9.

[0133] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0134] Same as Example 1.

[0135] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0136] Same as Example 1.

[0137] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0138] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 6.96 mL (6.53 g) of anhydrous N,N-dimethylacetamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 12%. The reaction system was reacted at 10°C for 12 h to obtain a A polyamic acid solution of a certain viscosity is prepared, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine is 2:1) is added dropwise. After continuing the reaction for 3 hours, the system is heated to 100°C to promote complete imidization. After the reaction is completed, the system temperature is lowered to room temperature and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, the product is dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structures.

[0139] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0140] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 6.96 mL (6.53 g) of anhydrous N, N-dimethylacetamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 12%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0141] Example 10.

[0142] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0143] Same as Example 1.

[0144] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0145] Same as Example 1.

[0146] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0147] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 8.14 mL (7.63 g) of anhydrous N, N-dimethylacetamide, and 0.444 g (1 mmol) of 4,4'- (hexafluoroisopropylene) diphthalic anhydride was added in batches under mechanical stirring to keep the solid content of the system at about 12%. The reaction system was reacted at 10°C for 12 h to obtain a A polyamic acid solution of a certain viscosity is prepared, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine is 2:1) is added dropwise. After continuing the reaction for 3 hours, the system is heated to 100°C to promote complete imidization. After the reaction is completed, the system temperature is lowered to room temperature and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, the product is dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structures.

[0148] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0149] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 8.14 mL (7.63 g) of anhydrous N, N-dimethylacetamide, and 0.444 g (1 mmol) of 4,4'- (hexafluoroisopropylene) diphthalic anhydride was added in batches under mechanical stirring to keep the solid content of the system at about 12%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0150] Example 11.

[0151] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0152] Same as Example 1.

[0153] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0154] Same as Example 1.

[0155] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0156] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 5.32 mL (5.04 g) of anhydrous N,N-dimethylformamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 h to obtain a A polyamic acid solution of a certain viscosity is prepared, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine is 2:1) is added dropwise. After continuing the reaction for 3 hours, the system is heated to 100°C to promote complete imidization. After the reaction is completed, the system temperature is lowered to room temperature and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, the product is dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structures.

[0157] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0158] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 5.32 mL (5.04 g) of anhydrous N, N-dimethylformamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0159] Example 12.

[0160] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0161] Same as Example 1.

[0162] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0163] Same as Example 1.

[0164] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0165] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 4.91 mL (5.04 g) of anhydrous N-methylpyrrolidone, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 h to obtain a A polyamic acid solution of a certain viscosity was prepared, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine was 2:1) was added dropwise. After continuing the reaction for 3 hours, the system was heated to 100°C to promote complete imidization. After the reaction was completed, the system temperature was lowered to room temperature and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, the product was dried in a vacuum oven to obtain a polyimide containing an amide bond and a benzonorbornane structure in a resin-like homopolymer structure.

[0166] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0167] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane was dissolved in 4.91 mL (5.04 g) of anhydrous N-methylpyrrolidone, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0168] Example 13.

[0169] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0170] Under the conditions of nitrogen and magnetic stirring, 4.92g (10mmol) of 3,6-bis (4-amino-2-trifluoromethylphenoxy) benzonorbornene and 30mL of anhydrous N,N-dimethylacetamide were placed in a reaction bottle with a branch, and 5mL of anhydrous pyridine was added as an acid binding agent. The mixture was stirred at room temperature (25°C) for 0.5h. Then 4.08g (22mmol) of 4-nitrobenzoyl chloride was dissolved in 30mL of anhydrous N,N-dimethylacetamide. The anhydrous N,N-dimethylacetamide solution containing 4-nitrobenzoyl chloride was placed in a constant pressure dropping funnel and slowly added dropwise to the reaction bottle at room temperature. The system was then heated to 80°C and refluxed for 6h. After the reaction was completed, the system was gradually cooled to room temperature. The mixed solution after the reaction was poured into a large amount of distilled water, and the solid was precipitated and collected, filtered, washed, and vacuum dried to obtain 7.11 g of brown-yellow powder, i.e., 3,6-bis(4-(4-nitrobenzamido)-2-trifluoromethylphenoxy)benzonorbornene;

[0171] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0172] Under the conditions of nitrogen and magnetic stirring, 1.58 g (2 mmol) of 3,6-bis (4- (4-nitrobenzamido) -2-trifluoromethylphenoxy) benzonorbornene and 50 mL of anhydrous ethanol were placed in a reaction bottle with a branch, stirred at room temperature (25 ° C) for 0.5 h, and then 0.15 g of palladium carbon (5%) was added, and 20 mL of hydrazine hydrate solution (50%) was gradually added dropwise, and then the system was heated to 80 ° C and refluxed, and reacted for 12 h. After cooling, it was filtered to remove the palladium carbon, and the filtrate was poured into a large amount of distilled water, crystallized at low temperature, and the precipitate was collected, filtered, washed, and vacuum dried to obtain 1.32 g of gray-white powder, i.e., 3,6-bis (4- (4-aminobenzamido) -2-trifluoromethylphenoxy) benzonorbornene.

[0173] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a homopolymer structure in the form of resin.

[0174] Under nitrogen conditions and 10°C, 0.73 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) -2-trifluoromethylphenoxy) benzonorbornane was dissolved in 6.19 mL (5.81 g) of anhydrous N, N-dimethylacetamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 h to obtain to a polyamic acid solution with a certain viscosity, and then 3 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine is 2:1) is added dropwise, and the reaction is continued for 3 hours, and then the system is heated to 100°C to promote complete imidization. After the reaction is completed, the system temperature is lowered to room temperature, and then poured into 20 mL of methanol to obtain a filamentous product. After repeated washing, it is dried in a vacuum oven to obtain a resin-shaped homopolymer structure containing amide bonds and benzonorbornane structures. Polyimide.

[0175] (4) Preparation of polyimide containing amide bonds and benzonorbornane structures with homopolymer structure in film morphology.

[0176] Under nitrogen conditions and 10°C, 0.73 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) -2-trifluoromethylphenoxy) benzonorbornane was dissolved in 6.19 mL (5.81 g) of anhydrous N, N-dimethylacetamide, and 0.294 g (1 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures of a homopolymer structure in the form of a thin film.

[0177] Example 14.

[0178] (1) Preparation of dinitro compounds containing amide bonds and benzonorbornene structures.

[0179] Same as Example 1.

[0180] (2) Preparation of diamine monomers containing amide bonds and benzonorbornane structures.

[0181] Same as Example 1.

[0182] (3) Preparation of polyimide containing amide bonds and benzonorbornane structures in a resin-like copolymer structure.

[0183] Under nitrogen conditions and 10°C, 0.596 g (1 mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornane and 0.200 g (1 mmol) of 4,4'-diaminodiphenyl ether were dissolved in 8.37 mL (7.84 g) of anhydrous N,N-dimethylacetamide. 0.588 g (2 mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was heated to 10°C. The mixture was reacted at 0°C for 12 hours to obtain a polyamic acid solution with a certain viscosity, and then 6 mL of a mixed solution of acetic anhydride and triethylamine (the volume ratio of acetic anhydride and triethylamine was 2:1) was added dropwise. After continuing the reaction for 3 hours, the system was heated to 100°C to promote complete imidization. After the reaction, the system temperature was lowered to room temperature and then poured into 40 mL of methanol to obtain a filamentous product. After repeated washing, the product was dried in a vacuum oven to obtain a polyimide containing an amide bond and a benzonorbornane structure in a copolymer structure in the form of a resin.

[0184] (4) Preparation of polyimide containing amide bonds and benzonorbornane structure in the form of a copolymer structure in the form of a film.

[0185] Under nitrogen conditions and 10°C, 0.596g (1mmol) of 3,6-bis (4- (4-aminobenzamido) phenoxy) benzonorbornene and 0.200g (1mmol) of 4,4'-diaminodiphenyl ether were dissolved in 8.37mL (7.84g) of anhydrous N,N-dimethylacetamide, and 0.588g (2mmol) of 3,3',4,4'-biphenyltetracarboxylic dianhydride was added in batches under mechanical stirring to keep the solid content of the system at about 15%. The reaction system was reacted at 10°C for 12h to obtain a polyamic acid solution with a certain viscosity, and the polyamic acid solution was cast to obtain a polyamic acid wet film. The wet film was kept at 60°C for 1 hour for shaping and curing, then heated to 70°C, kept at 70°C for 3 hours to remove the solvent, then heated to 100°C, kept at this temperature for 1 hour, then heated to 150°C, kept at this temperature for 1 hour, then heated to 200°C, kept at this temperature for 1 hour, then heated to 250°C, kept at this temperature for 0.5 hour, and finally heated to 300°C, kept at this temperature for 0.5 hour, and then peeled off from the glass substrate after cooling to obtain a polyimide containing amide bonds and benzonorbornane structures in the form of a copolymer structure in the form of a thin film.

[0186] Table 1 is a table of dielectric properties of polyimides containing amide bonds and benzonorbornane structures in thin film homopolymer and copolymer structures in the embodiments of the present invention (ε is the dielectric constant, D is the dielectric loss).

[0187]

[0188] Table 2 shows the solubility table of polyimides containing amide bonds and benzonorbornane structures with homopolymer structures and copolymer structures in the resin form in the examples of the present invention.

[0189]

[0190] In summary, the present invention provides a diamine monomer containing amide bonds and benzonorbornane structures, a polyimide containing amide bonds and benzonorbornane structures, and a preparation method thereof, including the preparation method of polyimides containing amide bonds and benzonorbornane structures with homopolymer structures (y = 1) in resin form and film form or copolymer structures (0 < y < 1). Its structural characteristics are that the main chain structure is connected by aromatic ether bonds, amide bonds, etc. and benzene rings. The amide bonds help form strong hydrogen bond interactions, enhancing the cohesive energy and mechanical strength of the polymer. With norbornane bicyclic as the side group, it destroys the regular stacking between macromolecules, increases the free volume between chain segments, improves the solubility and optical properties of the polymer, reduces the dielectric constant of the material, and at the same time ensures a certain degree of stacking between macromolecules, improving the glass transition temperature and thermal properties of the material. The introduction of the third monomer in the copolymer modification further broadens the properties of the material and reduces the cost. The preparation method of the present invention is easy to control and repeat, has few process steps, low raw material and production costs, is suitable for industrial production, and the obtained polyimide has excellent properties and has broad application prospects in the fields of films, coatings, fibers, and plastics. While ensuring excellent heat resistance and mechanical strength, the flexibility of the polyimide macromolecular chain is improved. The norbornene bicyclic structure coupled with the benzene ring has a certain spatial configuration, reducing the close packing and crystallization tendency of the polyimide molecular chain.

[0191] The above embodiments are detailed descriptions of the preferred embodiments of the present invention with reference to the accompanying drawings. Those skilled in the art fall within the protection scope of the present invention when making various formal modifications or changes to the above embodiments without departing from the essence of the present invention.

Claims

1. A diamine monomer containing an amide bond and a benzonorbornane structure, characterized in that the structural formula as follows: In the above structural formula, Ar1 refers to an aromatic structure bonded to an amide bond and an aromatic ether bond, and Ar2 refers to an aromatic structure bonded to an amide bond and a primary amino group; Wherein, Ar1 is selected from one of the following aromatic structures: Ar2 is selected from one of the following aromatic structures:

2. The method for preparing a diamine monomer containing an amide bond and a benzonorbornane structure according to claim 1, characterized in that The following steps are involved: (1) Preparation of a dinitro compound containing an amide bond and a benzonorbornene structure: under nitrogen conditions, an acid binding agent is added to an organic solvent solution of a diamine monomer containing a benzonorbornene structure, the mixture is stirred at room temperature for 0.5 h, an organic solvent solution of an acyl chloride nitrobenzene compound is added dropwise, and then the system is heated to reflux and stirred for 6 h. The reaction solution is poured into a large amount of water, a solid is precipitated, and the solid is filtered, washed, and vacuum dried to obtain a dinitro compound containing an amide bond and a benzonorbornene structure; (2) Preparation of a diamine monomer containing an amide bond and a benzonorbornene structure: under nitrogen conditions, an anhydrous ethanol solution is added to a dinitro compound containing an amide bond and a benzonorbornene structure, stirred at room temperature for 0.5 h, then palladium carbon is added, and a hydrazine hydrate solution is gradually added dropwise, and then the system is heated to 80° C. and refluxed, stirred for 12 h, cooled, filtered to remove the palladium carbon, and the filtrate is poured into a large amount of water, low-temperature crystallized, filtered, washed, and vacuum dried to obtain a diamine monomer containing an amide bond and a benzonorbornene structure; In the preparation of the dinitro compound described in step (1), the molar ratio of the diamine monomer containing a benzonorbornene structure to the acyl chloride nitrobenzene compound is 1:(1-1.1); The organic solvent used in the preparation of the dinitro compound in step (1) is one of N,N-dimethylformamide, N,N-dimethylacetamide or acetonitrile; The chloronitrobenzene compound used in the preparation of the dinitro compound described in step (1) is 4-nitrobenzoyl chloride, 2-nitrobenzoyl chloride, m-nitrobenzoyl chloride, 2-methyl-4-nitrobenzoyl chloride, 2-chloro-4-nitrobenzoyl chloride, 2-fluoro-4-nitrobenzoyl chloride, 2,5-difluoro-4-nitrobenzoyl chloride, 2-chloro-5-nitrobenzoyl chloride, 3-nitro-4-methylbenzoyl chloride, 2-methyl-3-nitrobenzoyl chloride, 2-fluoro-5-nitrobenzoyl chloride, One of nitrobenzoyl chloride, 2,6-dimethyl-3-nitrobenzoyl chloride, 2-chloro-4-fluoro-3-methyl-5-nitrobenzoyl chloride, 2-chloro-4-fluoro-5-nitrobenzoyl chloride, 3-nitro-4-methylamino-benzoyl chloride, 3-methyl-2-nitrobenzoyl chloride, 4-bromo-2-nitrobenzoyl chloride, 2-fluoro-6-nitrobenzoyl chloride, 4-fluoro-2-nitrobenzoyl chloride, and 2,4,5-trifluoro-3-methyl-6-nitrobenzoyl chloride; In the preparation of the diamine monomer described in step (2), the mass ratio of the dinitro compound containing an amide bond and a benzonorbornene structure, palladium carbon, hydrazine hydrate, and anhydrous ethanol is 1:0.1:4:

12.

3. A polyimide containing an amide bond and a benzonorbornane structure, characterized in that the structural formula as follows: In the above structural formula, Ar1, Ar2, Ar3 and Ar4 refer to aromatic structures bonded to amide groups, aromatic ether bonds and primary amino groups; n represents the degree of polymerization, which is an integer, n>0; When \(0 < y\leq1\), and \(y = 1\), the structural formula (Ⅱ) represents a polyimide with an amide bond and a benzonorbornane structure in a homopolymer form; when \(0 < y < 1\), the structural formula (Ⅱ) represents a polyimide with an amide bond and a benzonorbornane structure in a copolymer form; wherein, Ar1 is selected from one of the following aromatic structures: wherein, Ar2 is selected from one of the following aromatic structures: wherein, Ar3 is selected from one of the following aromatic structures: wherein, Ar4 is selected from one of the following aromatic structures:

4. The method for preparing a polyimide containing an amide bond and a benzonorbornane structure according to claim 3, characterized in that: comprising the following steps: When the polyimide with an amide bond and a benzonorbornane structure in a homopolymer form is in a resin form: Under a nitrogen atmosphere and at 5 - 10 °C, dissolve the diamine monomer with an amide bond and a benzonorbornane structure in an anhydrous organic solvent. Under mechanical stirring, add an equimolar amount of dianhydride monomer in batches. React the reaction system at 10 - 20 °C for 12 h to obtain a polyamic acid solution with a certain viscosity. Then, gradually add a mixed solution of a dehydrating agent and a catalyst, continue the reaction for 3 h, and then raise the temperature of the system to 100 °C to promote complete imidization. After the reaction is completed, cool the system temperature to room temperature, then pour it into methanol to obtain a filamentous product. After repeated washing, dry it in a vacuum oven to obtain the polyimide with an amide bond and a benzonorbornane structure in a homopolymer form in a resin form; When the polyimide with an amide bond and a benzonorbornane structure in a copolymer form is in a resin form: Under a nitrogen atmosphere and at 5 - 10 °C, dissolve the diamine monomer with an amide bond and a benzonorbornane structure and the diamine monomer without an amide bond and a benzonorbornane structure in an anhydrous organic solvent. Under mechanical stirring, add an equimolar amount of dianhydride monomer in batches. React the reaction system at 10 - 20 °C for 12 h to obtain a polyamic acid solution with a certain viscosity. Then, gradually add a mixed solution of a dehydrating agent and a catalyst, continue the reaction for 3 h, and then raise the temperature of the system to 100 °C to promote complete imidization. After the reaction is completed, cool the system temperature to room temperature, then pour it into methanol to obtain a filamentous product. After repeated washing, dry it in a vacuum oven to obtain the polyimide with an amide bond and a benzonorbornane structure in a copolymer form in a resin form; The anhydrous organic solvent is one of N,N - dimethylformamide, N,N - dimethylacetamide, or N - methylpyrrolidone; the solid content of the polyamic acid solution is 10 wt% - 15 wt%, and the solid content is equal to the sum of the masses of the added monomers / the sum of the added monomers and the mass of the anhydrous organic solvent.

5. The method for preparing a polyimide containing an amide bond and a benzonorbornane structure according to claim 3, characterized in that: comprising the following steps: When the polyimide with an amide bond and a benzonorbornane structure in a homopolymer form is in a film form: Under nitrogen conditions and at 5 to 10° C., a diamine monomer containing an amide bond and a benzonorbornene structure is dissolved in an anhydrous organic solvent, an equimolar amount of a dianhydride monomer is added in batches under mechanical stirring, the reaction system is reacted at 10 to 20° C. for 12 hours to obtain a polyamic acid solution with a certain viscosity, the polyamic acid solution is subjected to film casting to obtain a polyamic acid wet film, a solvent removal treatment and thermal imidization are sequentially performed, and the film is peeled off from a glass substrate after cooling to obtain a polyimide containing an amide bond and a benzonorbornene structure in a homopolymer structure in the form of a film; When the polyimide containing amide bonds and benzonorbornane structures of the copolymer structure is in the form of a film: Under nitrogen conditions and at 5 to 10° C., a diamine monomer containing an amide bond and a benzonorbornane structure and a diamine monomer not containing an amide bond and a benzonorbornane structure are dissolved in an anhydrous organic solvent, an equimolar amount of a dianhydride monomer is added in batches under mechanical stirring, the reaction system is reacted at 10 to 20° C. for 12 hours to obtain a polyamic acid solution with a certain viscosity, the polyamic acid solution is subjected to film casting to obtain a polyamic acid wet film, a solvent removal treatment and thermal imidization are sequentially performed, and the film is peeled off from a glass substrate after cooling to obtain a polyimide containing an amide bond and a benzonorbornane structure in a copolymer structure in the form of a film; The anhydrous organic solvent is one of N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone; the solid content of the polyamic acid solution with a certain viscosity is 10wt% to 15wt%, and the solid content is equal to the sum of the mass of the added monomer / the sum of the mass of the added monomer and the anhydrous organic solvent; The temperature of the desolventizing treatment in the preparation of the polyimide containing amide bonds and benzonorbornane structures of the homopolymer and copolymer structures in the form of thin films is 70 to 90° C. and the time is 3 to 6 hours; The heating procedure for thermal imidization in the preparation of the polyimide containing amide bonds and benzonorbornane structures of the homopolymer and copolymer structures in the form of thin films is: keep the temperature at 70°C for 3 hours, then heat it to 100°C, keep it for 1 hour, then heat it to 150°C, keep it for 1 hour; then heat it to 200°C, keep it for 1 hour; Then raise the temperature to 250℃ and keep it for 0.5h; finally raise the temperature to 300℃ and keep it for 0.5h.

6. The method for preparing a polyimide containing an amide bond and a benzonorbornane structure according to claim 4 or 5, characterized in that The diamine monomer containing no amide bond and benzonorbornane structure is one of 4,4'-diaminodiphenyl ether, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-2,2'-bistrifluoromethylbiphenyl, 2,2'-bis(4-aminophenyl)propane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane, 9,9'-bis(4-aminophenyl)fluorene, 4,4'-(1,4-phenylenedioxy)dianiline, 1,4'-bis(3-aminophenoxy)benzene or 4,4'-bis(4-aminophenoxy)biphenyl.

7. The method for preparing a polyimide containing an amide bond and a benzonorbornane structure according to claim 4 or 5, characterized in that The dianhydride monomer is one of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3',3,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,2',3,3'-diphenyl ether tetracarboxylic dianhydride, 2,3',3,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-diphenyl ketone tetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylene) diphthalic anhydride, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride or 3,3',4,4'-triphenyl bis(phenylene) ether tetracarboxylic dianhydride.

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