CN101654518B - Thermosetting polyimide resin and preparation method and application thereof - Google Patents

Abstract

式IThe invention discloses a norbornene-terminated polyimide resin, a preparation method and application thereof. The structural formula of the polyimide resin is shown in Formula I. The polyimide resin of the invention is prepared by using a reactive end-capping agent, an aromatic tetra-acid dianhydride and an aromatic diamine as raw materials by a PMR method. The polyimide resin provided by the invention can also be heat-treated to obtain resin molding powder. The molding powder has low melt viscosity, and after heat curing, a pure resin molded part with high mechanical properties and excellent heat resistance can be obtained. The polyimide resin is suitable for impregnating carbon fiber, glass fiber or aramid fiber, etc., to make a prepreg; the prepreg has good molding performance, and it can be processed by hot molding or vacuum autoclave after 50- Composite materials with low porosity, high mechanical properties and excellent heat resistance can be obtained after thermosetting molding at 320 °C. The composite material can be used to prepare high-temperature-resistant components in the fields of aviation, aerospace, space technology, etc., and can be used for a long time under the environment of 350-370°C.

Formula I

Description

A kind of thermosetting polyimide resin and its preparation method and application

technical field

The invention relates to a thermosetting polyimide resin and its preparation method and application.

Background technique

Thermosetting polyimide resin has a high glass transition temperature, excellent heat-resistant oxidation stability and mechanical properties. The composite material prepared by combining it with carbon fiber is the resin-based composite material with the highest temperature resistance level. As a quality Lightweight and high temperature resistant structural parts have important application value in aviation, aerospace, space technology and other fields. According to the type of reactive end-capping agent used, thermosetting polyimide resin is mainly divided into three major types: bismaleimide resin, PMR type polyimide resin and phenynyl-terminated polyimide resin. Among them, the most representative PMR type polyimide resin is PMR-15 resin (U.S. Patent 3,745,149), its heat resistance grade is 316°C, and the composite material prepared by combining it with carbon fiber can be used at a high temperature of 316°C long-term use. PMR-II-50 (NASA-TM-X-71894) has higher heat resistance, and its heat resistance grade is 371°C. However, the resin has poor melting performance and low molding process performance, making it difficult to prepare large or complex-shaped composite material components.

In recent years, it has been found that thermosetting polyimide resins containing asymmetric biphenylimide structures have excellent melting properties including low melt viscosity and melting temperature and good melt stability, while their thermosetting products have relatively High heat resistance. U.S. Patents (U.S.Patent 5,432,001, U.S.Patent 5,461,138, U.S.Patent 5,461,137) disclose norbornene dicarboxylic anhydride as a capping agent and a polyimide resin containing an asymmetric biphenylimide structure. However, these resins have high melt viscosity after heating and melting, so they are only suitable for the preparation of carbon fiber reinforced composite materials at a high temperature of 320 ° C by thermal molding process. U.S. Patent 7,015,304B1 discloses a phenylethynyl-terminated polyimide resin containing an asymmetric biphenylimide structure, which has a very low melt viscosity and is suitable for resin transfer molding Process for the preparation of carbon fiber reinforced composite materials resistant to 288-343 °C. However, this resin requires a higher temperature (>370°C) to complete the thermal curing crosslinking reaction.

Therefore, the development of polyimide resins with excellent melting properties, low curing temperature, high heat resistance and high mechanical properties is of great significance for the development of high temperature resistant carbon fiber reinforced composite materials.

Contents of the invention

The object of the present invention is to provide a kind of thermosetting polyimide resin and preparation method thereof.

The present invention provides a thermosetting polyimide resin with low melt viscosity and high heat resistance. The polyimide resin is not only suitable for thermocompression molding process, but also suitable for autoclave molding process. The fiber-reinforced composite material prepared at a high temperature of 320°C has excellent heat resistance and comprehensive mechanical properties.

The structural general formula of polyimide resin provided by the present invention is as shown in formula I,

(Formula I)

In formula I,

or

或

or

或

or

Said m=1-20, n=0.01-6.

According to the ratio of end-capping agent used, aromatic tetra-acid dianhydride and aromatic diamine, the number-average molecular weight of the polyimide resin is calculated to be 1000-9000 (due to the poor solubility of polyimide, it cannot be obtained by experiment method to determine the molecular weight).

The preparation method of above-mentioned polyimide resin comprises the following steps:

1) Esterifying the end-capping agent with an organic aliphatic alcohol solvent to obtain a monoacid monoester solution of the end-capping agent;

2) Esterifying the aromatic tetra-acid dianhydride with an organic aliphatic alcohol solvent to obtain an aromatic tetra-acid diester solution;

3) dissolving the aromatic diamine in an organic aliphatic alcohol solvent, then adding the end-capping agent monoacid monoester solution in step 1) and the aromatic tetraacid diester solution in step 2) to react to obtain the formula shown in I The polyimide resin solution;

Wherein, the capping agent is a compound shown in formula II,

(Formula II);

The aromatic tetra-acid dianhydride is a mixture of the following aromatic tetra-acid dianhydride I and aromatic tetra-acid dianhydride II, wherein the mass fraction of aromatic tetra-acid dianhydride I and aromatic tetra-acid dianhydride II The ratio is 100:1-30;

The aromatic tetra-acid dianhydride I is selected from one of the compounds shown in the following formula A1, formula A2, and formula A3:

Formula A1 Formula A2 Formula A3

The aromatic tetra-acid dianhydride II is selected from one of the compounds shown in the following formula B1, formula B2, and formula B3:

Formula B1 Formula B2 Formula B3

The aromatic diamine is selected from one of the following compounds:

p-phenylenediamine m-phenylenediamine 4,4'-diaminobenzidine 4,4'-diaminodiphenyl ether

3,4'-diaminodiphenyl ether 4,4'-diaminodiphenylmethane 4,4'-diaminobenzophenone

                

                

4,4'-Diaminodiphenylsulfone 2,2'-Dimethyl-4,4'-diaminobiphenyl 2,2'-Ditrifluoromethyl-4,4'-diaminobiphenyl

                       

                       

2,2',6,6'-tetramethyl-4,4'-diaminobiphenyl 2,2-bis(4-(4-aminophenoxy)phenyl)propane

                      

2,2-bis(4-(4-aminophenyl)hexafluoropropane 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane

1,4-bis(4-aminophenoxy) 1,3-bis(4-aminophenoxy)benzene

           

           

1,3-bis(3-aminophenoxy)benzene 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene

     

；

;

4,4'-bis(4-aminophenoxy)biphenyl 4,4'-bis(4-amino-2-trifluoromethylphenoxy)biphenyl

The ratio of the number of parts by mass of the end-capping agent, aromatic tetra-acid dianhydride and aromatic diamine is 5-80:100:30-150 in sequence.

The reaction temperature of the reaction in step 3) is 5-40° C., and the reaction time is 1-10 hours.

Wherein, the organic fatty alcohol solvent described in step 1), step 2) and step 3) is at least one of methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, n-pentyl alcohol in the following alcohols Alcohol, isoamyl alcohol, tert-butanol; or a mixture of one of the above alcohols mixed with at least one of the following solvents in any proportion: acetone, tetrahydrofuran, dioxane, benzene, toluene, chloroform and methylene chloride .

The mass fraction ratio of the capping agent and the organic aliphatic alcohol solvent in step 1) can be 5-80:5-600; the esterification reaction described in 1) is carried out under the condition of heating and refluxing at 65-140°C, and the reaction The time can be 1-6 hours.

The mass fraction ratio of the aromatic tetra-acid dianhydride to the organic aliphatic alcohol solvent in step 2) can be 100:60-1200; the esterification reaction in step 2) is carried out under the condition of heating and refluxing at 65-140°C , The reaction time can be 1-6 hours.

The mass fraction of aromatic diamine and organic aliphatic alcohol solvent described in step 3) can be 30-150:10-800.

The solution of polyimide resin provided by the present invention can also obtain resin molding powder (i.e. solid polyimide resin) after heat treatment, and molding powder has low melt viscosity, obtains mechanical properties after thermosetting Pure resin molded parts with high heat resistance and excellent performance.

Another object of the present invention is to provide the application of the polyimide resin represented by formula I in the preparation of polyimide resin-based composite materials. The polyimide resin of the present invention is suitable for impregnating carbon fiber, glass fiber or aramid fiber etc. to make prepreg (tape or cloth); Composite materials with low porosity, high mechanical properties and excellent heat resistance can be obtained after thermosetting molding at 50-320 °C in the autoclave process. The glass transition temperature of the composite material is between 350-450°C, it can be used to prepare high-temperature-resistant components in the fields of aviation, aerospace, space technology, etc., and it can be used for a long time under the environment of 350-370°C.

Detailed ways

The experimental methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials, unless otherwise specified, can be obtained from commercial sources.

The structural formulas of A1, A2, A3, B1, B2, B3 compounds in the following examples are as follows:

Embodiment 1, the preparation of polyimide resin and the performance of resin molding

1) 36 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 86° C. for 4 hours in 48 parts by mass of ethanol to obtain a norbornene dicarboxylic acid monoester solution (NE).

2) Heat reflux 90 parts by mass of compound A ₁ in 135 parts by mass of ethanol at 83°C for 3 hours to obtain an esterified solution of compound A ₁ , and heat reflux 10 parts by mass of compound B ₁ in 15 parts by mass of ethanol at 85°C for 4 hours to obtain The esterification product solution of compound _B1 .

3) Dissolve 50 parts by mass of m-phenylenediamine in 68 parts by mass of ethanol, stir for half an hour, then add the above-prepared NE, the esterification solution of compounds _A1 and _B1 in sequence, and stir and react at 20°C for 8 hours to obtain The homogeneous polyimide matrix resin solution has a calculated number average molecular weight of 1530, m in formula I is 2.79, and n is 0.28.

The resin solution obtained in step 3) is heated and heat-treated at 70°C/3h, 140°C/2h, and 200°C/1h to obtain resin molding powder, and its minimum melt viscosity is measured to be 70Pa.s; the molding powder After thermal curing at 250-320°C and 2MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 380°C (measured by DMA method), the tensile strength is greater than 85MPa, and the bending strength is greater than 130MPa.

Embodiment 2, the preparation of polyimide resin and the performance of carbon fiber polyimide composite laminate

1) 28 parts by mass of the capping agent norbornene dicarboxylic anhydride were heated to reflux at 68° C. for 2 hours in 31 parts by mass of methanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 72 parts by mass of compound A ₁ in 80 parts by mass of methanol to reflux at 69°C for 3 hours to obtain an esterification product solution of compound A ₁ , and heat 9 parts by mass of compound B ₂ to reflux at 70°C in 9 parts by mass of methanol for 5 hours to obtain compound Esterate solution of _B2 .

3) Dissolve 72 parts by mass of 3,4'-diaminodiphenyl ether in 60 parts by mass of methanol, stir for half an hour, then add NE, the esterified solution of compounds A ₁ and B ₂ in sequence, and stir at 30°C for 5 hours , to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight is 1970, m in formula I is 2.87, and n is 0.34.

Compound the resin solution obtained in step 3) with carbon fiber on a winding machine to prepare a prepreg, cut and lay up the prepreg, and heat-cure at 50-320°C and 3MPa pressure to obtain a carbon fiber polyimide composite material laminate.

It is measured that the glass transition temperature of the laminate is greater than 360° C. (measured by DMA method), the bending strength is greater than 1400 MPa, the flexural modulus is greater than 100 GPa, and the interlaminar shear strength is greater than 80 MPa.

Embodiment 3, the preparation of polyimide resin and the performance of resin molding

1) 19 parts by mass of end-capping agent norbornene dicarboxylic anhydride was heated to reflux at 70° C. for 2 hours in 22 parts by mass of methanol to obtain norbornene dicarboxylic acid monoester solution (NE).

2) Heat 37 parts by mass of Compound A ₂ in 52 parts by mass of ethanol at 84°C for 5 hours to obtain an esterified product solution of Compound A ₂ , and heat 9 parts by mass of Compound B ₁ in 13 parts by mass of ethanol at 85°C for 2 hours to obtain The esterification product solution of compound _B1 .

3) Dissolve 45 parts by mass of 4,4'-diaminodiphenylmethane in 34 parts by mass of methanol, and after stirring for half an hour, add the above-mentioned NE, the esterification solution of compounds A ₂ and B ₁ in sequence, and stir at 20°C for 4 hours, a homogeneous polyimide matrix resin solution was obtained, and the calculated number average molecular weight was 1680, m in formula I was 1.96, and n was 0.48.

The resin solution obtained in step 3) is heated and heat-treated at 80°C/3h, 150°C/2h, and 210°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 120Pa.s; the molding powder After thermal curing at 250-320°C and 3MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 360°C (measured by DMA method), the tensile strength is greater than 75MPa, and the bending strength is greater than 130MPa.

Embodiment 4, the preparation of polyimide resin and the performance of resin molding

1) 47 parts by mass of norbornene dicarboxylic anhydride, an end-capping agent, was heated to reflux at 86° C. for 5 hours in 60 parts by mass of ethanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 120 parts by mass of Compound A ₂ in 175 parts by mass of ethanol at 82°C for 6 hours to obtain an esterified product solution of Compound A ₂ , and heat 24 parts by mass of Compound B ₂ in 30 parts by mass of ethanol at 83°C for 4 hours to obtain The esterification product solution of compound _B2 .

3) Dissolve 175 parts by mass of 1,3-bis(4-aminophenoxy)benzene in 120 parts by mass of ethanol, and after stirring for half an hour, add NE, the esterification solution of compounds A ₂ and B ₂ in sequence, and heat at 40°C Stir for 4 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight is 2390, m in formula I is 2.57, and n is 0.54.

The resin solution obtained in step 3) is heated and heat-treated at 80°C/3h, 140°C/2h, and 220°C/1h to obtain resin molding powder, and its minimum melt viscosity is measured to be 8Pa.s; the molding powder After thermal curing at 250-320°C and 2MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 350°C (measured by DMA method), the tensile strength is greater than 70MPa, and the bending strength is greater than 110MPa.

Embodiment 5, the preparation of polyimide resin and the performance of resin molding

1) 15 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 82° C. for 2 hours in 20 parts by mass of ethanol to obtain a norbornene dicarboxylic acid monoester solution (NE).

2) Heat 48 parts by mass of compound A ₃ in 46 parts by mass of methanol to reflux at 68°C for 4 hours to obtain an esterification product solution of compound A ₃ , and heat 5 parts by mass of compound B ₂ to reflux at 69°C in 5 mass parts of methanol for 4 hours to obtain The esterification product solution of compound _B2 .

3) Dissolve 78 parts by mass of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene in 80 parts by mass of ethanol, stir for half an hour and then add the NE prepared above, compound A ₃ and The esterified product solution of B ₂ was stirred at 25°C for 9 hours to obtain a homogeneous polyimide matrix resin solution with a calculated number average molecular weight of 3170, m in formula I was 2.93, and n was 0.35.

The resin solution obtained in step 3) is heated and heat-treated at 70°C/3h, 140°C/2h, and 230°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 28Pa.s; the molding powder After thermal curing at 250-320°C and 1.5MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 350°C (measured by DMA method), the tensile strength is greater than 80MPa, and the bending strength is greater than 120MPa.

Embodiment 6, the preparation of polyimide resin and the performance of resin molding

1) 59 parts by mass of the capping agent norbornene dicarboxylic anhydride were heated to reflux at 67° C. for 2 hours in 62 parts by mass of methanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 193 parts by mass of compound A ₂ in 172 parts by mass of methanol at 68°C for 5 hours to obtain an esterification product solution of compound A ₂ , and heat 20 parts of compound B ₃ in 18 parts of methanol at 70°C for 2 hours to obtain compound B ₃ esterification solution.

3) Dissolve 318 parts by mass of 4,4'-bis(4-amino-2-trifluoromethylphenoxy)biphenyl in 285 parts of methanol, and after stirring for half an hour, add the above-prepared NE and compound A ₂ and the esterified product solution of _B3 , stirred at 35°C for 5 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight was 3640, m in formula I was 3.29, and n was 0.25.

The resin solution obtained in step 3) is heated and heat-treated at 60°C/3h, 150°C/2h, and 230°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 45Pa.s; the molding powder After thermal curing at 250-320°C and 2MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 360°C (measured by DMA method), the tensile strength is greater than 75MPa, and the bending strength is greater than 130MPa.

Embodiment 7, the preparation of polyimide resin and the performance of carbon fiber polyimide composite laminate

1) 66 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 80° C. for 6 hours in 88 parts by mass of ethanol to obtain a norbornene dicarboxylic acid monoester solution (NE).

2) Heat 160 parts by mass of Compound A ₁ in 225 parts by mass of ethanol at 81°C for 4 hours to obtain an esterification product solution of Compound A ₁ , and heat 18 parts by mass of Compound B ₃ in 24 parts by mass of ethanol at 83°C for 5 hours to obtain The esterification product solution of compound _B3 .

3) Dissolve 54 parts by mass of m-phenylenediamine and 36 parts of p-phenylenediamine in 140 parts by mass of ethanol, and after stirring for half an hour, add the above-prepared NE, the esterified solution of compounds A ₁ and B ₃ in sequence, at 40°C Stir for 8 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight is 1500, m in formula I is 2.71, and n is 0.20.

Compound the resin solution obtained in step 3) with carbon fiber on a winding machine to prepare a prepreg, cut and lay up the prepreg, and heat-cure it at 50-320°C and 4MPa pressure to obtain a carbon fiber polyimide composite material laminate.

It is measured that the glass transition temperature of the laminate is greater than 410° C. (measured by DMA method), the bending strength is greater than 1500 MPa, the bending modulus is greater than 130 GPa, and the interlaminar shear strength is greater than 60 MPa.

Embodiment 8, the preparation of polyimide resin and the performance of carbon fiber polyimide composite laminate

1) 26 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 84° C. for 2 hours in 33 parts by mass of ethanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 54 parts by mass of Compound A ₁ in 82 parts by mass of ethanol at 83°C for 6 hours to obtain an esterification product solution of Compound A ₁ , and heat 15 parts by mass of Compound B ₁ in 21 parts by mass of ethanol at 82°C for 4 hours to obtain The esterification product solution of compound _B1 .

3) Dissolve 17 parts by mass of p-phenylenediamine and 31 parts by mass of 4,4'-diaminodiphenyl ether in 52 parts by mass of ethanol, and after stirring for half an hour, add the above-prepared NE, compounds A ₁ and B ₁ in sequence The esterified product solution was stirred at 30°C for 7 hours to obtain a homogeneous polyimide matrix resin solution with a calculated number average molecular weight of 1660, m in formula I being 2.32, and n being 0.59.

Compound the resin solution obtained in step 3) with carbon fiber on a winding machine to prepare a prepreg, cut and lay up the prepreg, and heat-cure at 50-320°C and 3MPa pressure to obtain a carbon fiber polyimide composite material laminate.

It is measured that the glass transition temperature of the laminate is greater than 400°C (measured by DMA method), the bending strength is greater than 1500MPa, the bending modulus is greater than 110GPa, and the interlaminar shear strength is greater than 75MPa.

Embodiment 9, the preparation of polyimide resin and the performance of resin molding

1) 18 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 70° C. for 1 hour in 20 parts by mass of methanol to obtain a norbornene dicarboxylic acid monoester solution (NE).

2) Heat 34 parts by mass of compound A ₁ in 39 parts by mass of methanol to reflux at 68°C for 4 hours to obtain an esterification product solution of compound A ₁ , and heat 7 parts by mass of compound B ₂ to reflux at 67°C in 8 mass parts of methanol for 3 hours to obtain The esterification product solution of compound _B2 .

3) Dissolve 30 parts by mass of 4,4'-diaminodiphenyl ether and 15 parts by mass of 4,4'-diaminodiphenylmethane in 34 parts of methanol, stir for half an hour and then add the above-prepared NE and compound A in sequence The esterified product solution of ₁ and B ₂ was stirred at 40°C for 10 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight was 1650, m in formula I was 2.11, and n was 0.41.

The resin solution obtained in step 3) is heated and heat-treated at 70°C/3h, 140°C/2h, and 220°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 110Pa.s; the molding powder After thermal curing at 250-320°C and 3MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 370°C (measured by DMA method), the tensile strength is greater than 75MPa, and the bending strength is greater than 130MPa.

Embodiment 10, the preparation of polyimide resin and the performance of resin molding

1) 24 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 85° C. for 6 hours in 33 parts by mass of ethanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 63 parts by mass of Compound A ₂ in 86 parts by mass of ethanol at 83°C to reflux for 3 hours to obtain an esterified product solution of Compound A ₂ , and heat 6 parts by mass of Compound B ₃ in 9 parts by mass of ethanol to reflux at 86°C for 5 hours to obtain The esterification product solution of compound _B3 .

3) Dissolve 16 parts by mass of m-phenylenediamine, 32 parts by mass of 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, and 15 parts by mass of 3,4'-diaminodiphenyl ether In 60 parts by mass of ethanol, after stirring for half an hour, add the esterified solution of NE, compound A ₂ and B ₃ prepared above in sequence, and stir at 20°C for 3 hours to obtain a homogeneous polyimide matrix resin solution, and calculate the number average The molecular weight is 1940, and m is 2.64 in formula I, and n is 0.18.

The resin solution obtained in step 3) is heated and heat-treated at 70°C/3h, 150°C/2h, and 210°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 50Pa.s; the molding powder After thermal curing at 250-320°C and 4MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 360°C (measured by DMA method), the tensile strength is greater than 70MPa, and the bending strength is greater than 120MPa.

Embodiment 11, the preparation of polyimide resin and the performance of resin molding

1) 21 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 81° C. for 3 hours in 28 parts by mass of ethanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 48 parts by mass of Compound A ₁ in 70 parts by mass of ethanol at 84°C for 4 hours to obtain an esterified product solution of Compound A ₁ , and heat 9 parts by mass of Compound B ₁ in 12 parts by mass of ethanol at 82°C for 3 hours to obtain The esterification product solution of compound _B1 .

3) Dissolve 39 parts of 1,3-bis(4-aminophenoxy)benzene, 13 parts of 3,4'-diaminodiphenyl ether, and 19 parts of 1,4-bis(4-aminophenoxy)benzene In a mixed solvent of 60 parts of ethanol and 15 parts of acetone, after stirring for half an hour, add the above-prepared NE, compound A ₁ and the esterification solution of B ₁ in sequence, and stir at 35°C for 7 hours to obtain a homogeneous polyimide matrix The resin solution has a calculated number average molecular weight of 2150, m in formula I is 2.55, and n is 0.44.

The resin solution obtained in step 3) is heated and heat-treated at 80°C/3h, 140°C/2h, and 200°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 75Pa.s; the molding powder After thermal curing at 250-320°C and 2MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 350°C (measured by DMA method), the tensile strength is greater than 75MPa, and the bending strength is greater than 120MPa.

Example 12, preparation of polyimide resin and performance of carbon fiber polyimide composite laminate

1) 14 parts by mass of end-capping agent norbornene dicarboxylic anhydride was heated to reflux at 86° C. for 4 hours in 18 parts by mass of ethanol to obtain the corresponding norbornene dicarboxylic acid monoester solution (NE).

2) Heat 42 parts by mass of compound A ₃ in 53 parts by mass of ethanol at 82°C to reflux for 3 hours to obtain an esterified product solution of compound A ₃ , and heat 4 mass parts of compound B ₃ in 6 mass parts of ethanol to reflux at 83°C for 2 hours to obtain The esterification product solution of compound _B3 .

3) 6 parts by mass of p-phenylenediamine, 11 parts by mass of 4,4'-diaminodiphenylmethane, 24 parts by mass of 4,4'-bis(4-amino-2-trifluoromethylphenoxy) Benzene was dissolved in 32 parts by mass of ethanol, and after stirring for half an hour, the esterified solution of NE, compound _A3 and _B3 prepared above was added in sequence, and stirred at 40°C for 9 hours to obtain a homogeneous polyimide matrix resin solution, calculated The number average molecular weight is 2290, m is 2.75 in formula I, and n is 0.21.

Compound the resin solution obtained in step 3) with carbon fiber on a winding machine to prepare a prepreg, cut and lay up the prepreg, and heat-cure at 50-320°C and 3MPa pressure to obtain a carbon fiber polyimide composite material laminate.

It is measured that the glass transition temperature of the laminate is greater than 370°C (measured by DMA method), the bending strength is greater than 1300MPa, the bending modulus is greater than 90GPa, and the interlaminar shear strength is greater than 70MPa.

Example 13, preparation of polyimide resin and properties of resin molded parts

1) 44 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 68° C. for 1 hour in 45 parts by mass of methanol to obtain a norbornene dicarboxylic acid monoester solution (NE).

2) Heat 100 parts by mass of compound A ₁ in 105 parts by mass of methanol to reflux at 69°C for 4 hours to obtain an esterification solution of compound A ₁ , and heat 1 mass part of compound B ₂ in 1 mass part of methanol to reflux at 67°C for 3 hours to obtain The esterification product solution of compound _B2 .

3) Dissolve 149 parts by mass of 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl in 130 parts of ethanol, stir for half an hour and then add the above-prepared NE, compounds A ₁ and B ₂ in sequence The esterified product solution was stirred at 35°C for 8 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight was 2080, m in formula I was 2.54, and n was 0.02.

The resin solution obtained in step 3) is heated and heat-treated at 60°C/3h, 140°C/2h, and 220°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 130Pa.s; the molding powder After thermal curing at 250-320°C and 3MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 360°C (measured by DMA method), the tensile strength is greater than 70MPa, and the bending strength is greater than 120MPa.

Example 14, Preparation of polyimide resin and properties of resin molded parts

1) 5 parts by mass of end-capping agent norbornene dicarboxylic anhydride was heated to reflux at 69° C. for 3 hours in 6 parts by mass of methanol to obtain norbornene dicarboxylic acid monoester solution (NE).

2) Heat 80 parts by mass of compound A ₁ in 78 parts by mass of methanol to reflux at 67°C for 5 hours to obtain an esterified product solution of compound A ₁ , and heat 20 parts by mass of compound B ₃ to reflux at 68°C in 25 parts by mass of methanol for 4 hours to obtain The esterification product solution of compound _B3 .

3) Dissolve 24 parts by mass of m-phenylenediamine and 23 parts by mass of 3,4'-diaminodiphenyl ether in 45 parts of methanol, and after stirring for half an hour, add the esters of NE, compounds A ₁ and B ₃ prepared above in sequence The compound solution was stirred at 30°C for 8 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight was 8950, m in formula I was 17.85, and n was 2.95.

The resin solution obtained in step 3) is heated and heat-treated at 60°C/3h, 150°C/2h, and 200°C/1h in turn to obtain resin molding powder, and its minimum melt viscosity is measured to be 2300Pa.s; the molding powder After thermal curing at 250-320°C and 3MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 350°C (measured by DMA method), the tensile strength is greater than 80MPa, and the bending strength is greater than 120MPa.

Example 15, Preparation of polyimide resin and properties of resin molded parts

1) 80 parts by mass of the capping agent norbornene dicarboxylic anhydride was heated to reflux at 83° C. for 3 hours in 110 parts by mass of ethanol to obtain a norbornene dicarboxylic acid monoester solution (NE).

2) Heat 95 parts by mass of compound A ₁ in 125 parts by mass of ethanol at 85°C for 4 hours to obtain an esterification product solution of compound A ₁ , and heat 5 parts by mass of compound B ₂ in 8 mass parts of ethanol at 82°C for 4 hours to obtain The esterification product solution of compound _B2 .

3) Dissolve 55 parts by mass of 4,4'-diaminodiphenyl ether and 55 parts by mass of 3,4'-diaminodiphenyl ether in 105 parts of ethanol, stir for half an hour and then add the above-prepared NE and compound A in sequence The esterified solution of ₁ and B ₂ was stirred at 25°C for 6 hours to obtain a homogeneous polyimide matrix resin solution with a calculated number average molecular weight of 1130, m in formula I was 1.33, and n was 0.07.

The resin solution obtained in step 3) is heated and heat-treated at 80°C/3h, 140°C/2h, and 200°C/1h to obtain resin molding powder, and its minimum melt viscosity is measured to be 45Pa.s; the molding powder After thermal curing at 250-320°C and 2MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 360°C (measured by DMA method), the tensile strength is greater than 50MPa, and the bending strength is greater than 110MPa.

Example 16, Preparation of polyimide resin and properties of resin molded parts

1) 24 parts by mass of end-capping agent norbornene dicarboxylic anhydride was heated to reflux at 69° C. for 3 hours in 20 parts by mass of methanol to obtain norbornene dicarboxylic acid monoester solution (NE).

2) Heat 75 parts by mass of Compound A ₂ in 85 parts by mass of methanol to reflux at 68°C for 4 hours to obtain an esterified product solution of Compound A ₂ , and heat 25 parts by mass of Compound B ₃ to reflux at 68°C in 26 parts by mass of methanol for 4 hours to obtain The esterification product solution of compound _B3 .

3) Dissolve 20 parts by mass of m-phenylenediamine and 10 parts by mass of 3,4'-diaminodiphenyl ether in 35 parts of methanol, and after stirring for half an hour, add the esters of NE, compounds A ₂ and B ₃ prepared above in sequence The compound solution was stirred at 20°C for 6 hours to obtain a homogeneous polyimide matrix resin solution, the calculated number average molecular weight was 2150, m in formula I was 3.15, and n was 0.77.

The resin solution obtained in step 3) is successively heated and heat-treated at 60°C/3h, 140°C/2h, and 200°C/1h to obtain a resin molding powder, and its minimum melt viscosity is measured to be 170Pa.s; the molding powder After thermal curing at 250-320°C and 2MPa pressure, a pure resin molded part can be obtained. The glass transition temperature of the resin molded part is greater than 350°C (measured by DMA method), the tensile strength is greater than 60MPa, and the bending strength is greater than 110MPa.

Claims (10)

1. general structural formula is as the polyimide resin shown in formula I,

(Formula I) In formula I,

R ₂ =

-O-, or

Said m=1-20, n=0.01-6. 2. The polyimide resin according to claim 1, characterized in that: the number average molecular weight of the polyimide resin is 1000-9000. 3. a method for preparing the polyimide resin shown in formula I described in claim 1, comprises the following steps: 1) Esterifying the end-capping agent with an organic aliphatic alcohol solvent to obtain a monoacid monoester solution of the end-capping agent; 2) Esterifying the aromatic tetra-acid dianhydride with an organic aliphatic alcohol solvent to obtain an aromatic tetra-acid diester solution; 3) dissolving the aromatic diamine in an organic aliphatic alcohol solvent, then adding the end-capping agent monoacid monoester solution in step 1) and the aromatic tetraacid diester solution in step 2) to react to obtain the formula shown in I The polyimide resin solution; Wherein, the capping agent is a compound shown in formula II, (Formula II); The aromatic tetra-acid dianhydride is a mixture of the following aromatic tetra-acid dianhydride I and aromatic tetra-acid dianhydride II, wherein the mass fraction of aromatic tetra-acid dianhydride I and aromatic tetra-acid dianhydride II The ratio is 100:1-30; The aromatic tetra-acid dianhydride I is selected from one of the compounds shown in the following formula A1, formula A2, and formula A3: Type A1 Type A2 Type A3 The aromatic tetra-acid dianhydride II is selected from one of the compounds shown in the following formula B1, formula B2, and formula B3:

Formula B1 Formula B2 Formula B3 The aromatic diamine is selected from one of the following compounds:

The ratio of the number of parts by mass of the end-capping agent, aromatic tetra-acid dianhydride and aromatic diamine is 5-80:100:30-150 in sequence. 4. The method according to claim 3, characterized in that: the reaction temperature of the reaction in step 3) is 5-40° C., and the reaction time is 1-10 hours. 5. according to the described method of claim 3 or 4, it is characterized in that: organic fatty alcohol solvent described in step 1), step 2) and step 3) is at least one in following alcohol: methyl alcohol, ethanol, propane Alcohol, isopropanol, n-butanol, isobutanol, n-pentanol, isoamyl alcohol, and tert-butanol; or a mixture of any of the above alcohols in any proportion with at least one of the following solvents: acetone, tetrahydrofuran , dioxane, benzene, toluene, chloroform and dichloromethane. 6. The method according to claim 3, characterized in that: the mass and number ratio of the capping agent and the organic fatty alcohol solvent in step 1) is 5-60: 5-600; the ester described in step 1) The reaction is carried out under the condition of heating and reflux at 65-140° C., and the reaction time is 1-6 hours. 7. The method according to claim 3, characterized in that: the mass fraction ratio of aromatic tetraacid dianhydride and organic aliphatic alcohol solvent described in step 2) is 100: 60-1200; described in step 2) The esterification reaction is carried out under the condition of heating and refluxing at 65-140° C., and the reaction time is 1-6 hours. 8. The method according to claim 3, characterized in that: in step 3), the ratio of aromatic diamine to organic aliphatic alcohol solvent in parts by mass is 30-150:10-800. 9. The method according to claim 3, characterized in that: said method further comprises the step of heat-treating the polyimide resin solution obtained in step 3) to obtain a solid polyimide resin. 10. the application of polyimide resin shown in formula I described in claim 1 in the preparation polyimide resin-based composite material. the