阅读说明：本技术 一种二胺单体、本征型高介电低损耗聚酰亚胺及其制备方法与应用 (Diamine monomer, intrinsic high-dielectric low-loss polyimide, and preparation method and application thereof ) 是由 张艺 郑维文 刘川 梁孝慈 蒋星 刘四委 池振国 许家瑞 于 2021-09-23 设计创作，主要内容包括：本发明公开了一种二胺单体、本征型高介电低损耗聚酰亚胺及其制备方法与应用,属于材料科学技术领域,采用含砜基侧链的二胺单体与均苯四甲酸二酐等商品化二酐单体为原料,在室温下聚合后进行酰亚胺化得到本征型高介电低损耗聚酰亚胺材料,本发明制备的聚酰亚胺材料具有高介电常数、低介电损耗,同时具有优异的热稳定性。本发明的聚酰亚胺制备工艺简单,普适性强,可用于大规模工业生产；本发明制备的聚酰亚胺可应用于制备高介电材料,可适用于储能材料、光电器件、信息产业等高新技术领域,特别是在有机场效应晶体管方面的应用。(The invention discloses a diamine monomer, intrinsic high-dielectric low-loss polyimide, a preparation method and application thereof, and belongs to the technical field of material science. The polyimide has simple preparation process and strong universality, and can be used for large-scale industrial production; the polyimide prepared by the invention can be applied to preparing high dielectric materials, can be suitable for high and new technical fields such as energy storage materials, photoelectric devices, information industries and the like, and is particularly applied to the aspect of organic field effect transistors.)

1. A diamine monomer, characterized in that the molecular structural formula is:

wherein R is₁is-NH₂or-Ph-NH₂，R₂、R₃Is a substituent containing a sulfone group structure or-H.

2. An intrinsic high dielectric low loss polyimide comprising the diamine monomer of claim 1, having a general molecular structure of:

wherein: m and n represent polymerization degrees, and m/n is 1/99-100/0; x₁、X₂Is a tetravalent aromatic or aliphatic hydrocarbon radical, Y₁Is the diamine monomer.

3. The intrinsic type high dielectric low loss polyimide of claim 2, wherein R is selected from the group consisting of₂、R₃One or two of which are selected from one of the following structural formulas:

wherein p is more than or equal to 0, q is more than or equal to 0, and t is more than or equal to 0.

4. The intrinsic type high dielectric low loss polyimide as claimed in claim 2, wherein X is₁、X₂Identical or different, X₁、X₂Is a tetravalent aromatic or aliphatic hydrocarbon group selected from the following structures:

5. the intrinsic type high dielectric low loss polyimide as claimed in claim 2, wherein Y is₂Is a diamine residue selected from the following structures:

6. a method for preparing the intrinsic type high dielectric and low loss polyimide according to any one of claims 2 to 5, comprising the following steps: in an inert argon or nitrogen atmosphere, will have Y₁Diamine monomer of structure (I) or having Y₁And Y₂Mixed diamine monomers of structure with X₁Dianhydride monomer of structure X₁And X₂Mixed diamine monomers of structure (I) are mixed according to a molar ratio of 1: (0.9-1.1) dissolving in an aprotic polar organic solvent, stirring and reacting for 24-72 h at normal temperature to obtain a polyamic acid glue solution, and performing dehydration and imidization to obtain the intrinsic high-dielectric low-loss polyimide.

7. The method according to claim 6, wherein Y is contained₁Diamine monomer of structure (II) or containing Y₁Structure and Y₂Mixed diamine monomers of structure and containing X₁Dianhydride monomer of structure or containing X₁Structure and X₂The sum of the mass of the mixed dianhydride monomers with the structure is 1 to 50 percent of the mass of the used reaction solvent.

8. The production method according to claim 6, wherein the aprotic polar organic solvent is one or a mixture of two or more selected from the group consisting of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, dimethylsulfone, sulfolane and m-cresol.

9. The method according to claim 6, wherein the polyamic acid solution is subjected to a dehydration imidization to form a polyimide, and the dehydration imidization is a thermal imidization or a chemical imidization.

10. Use of the intrinsic high dielectric and low loss polyimide according to any one of claims 2 to 5 in the field of high capacitance energy storage materials or optoelectronic devices.

Technical Field

The invention relates to the technical field of material science, in particular to diamine monomer, intrinsic high-dielectric low-loss polyimide, and a preparation method and application thereof.

Background

With the rapid development of modern electronic information technology and nanotechnology, people put higher demands on the comprehensive performance of materials. As one of the key materials, the conventional high dielectric material has been difficult to meet the requirements of advanced electrical and electronic technology, and therefore, the development of a novel high dielectric material with excellent performance is an urgent need for those skilled in the art. The concept of high dielectric materials is derived from the semiconductor industry, and in general, materials with a high dielectric constant compared to silicon dioxide are referred to as high dielectric materials (> 3.9).

Compared with the traditional inorganic material, the polymer has the advantages of easy processing, small density, low cost, breakdown resistance, good toughness and the like, and plays an irreplaceable role in the field of dielectric materials. However, the low dielectric constant of polymers limits their large-scale application in high dielectric applications. In order to increase the dielectric constant of the material, the conventional method is to add high dielectric inorganic filler into the polymer to prepare high dielectric polymer composite materials, such as CN103951917A, CN104046023A and CN 103465576A. However, due to the compatibility problem of the inorganic filler with the organic polymer, the breakdown strength of the resulting composite material is reduced and the mechanical properties are degraded. Therefore, in recent years, researchers have attracted extensive attention to design synthetic intrinsic high dielectric polymer materials.

Polyimide is a high molecular polymer with a molecular main chain containing an imide ring structure. As a classical special functional plastic, polyimide has the advantages of excellent high temperature resistance and low temperature resistance, outstanding film forming property, good designability, high electrical insulation and the like, and has wide application prospect and great commercial value in high and new technical fields of electrical insulation, microelectronics, automobile medical treatment, material packaging, aerospace and the like. The traditional polyimide has a low dielectric constant (3.5) and is difficult to meet the requirements of the technical fields of modern electronic information and energy.

Disclosure of Invention

The invention aims to provide a diamine monomer and intrinsic polyimide with high dielectric and low loss performance of the diamine monomer, which has high dielectric constant, low dielectric loss, excellent thermal stability and chemical resistance and good film forming property and can be applied to capacitive energy storage materials and photoelectric devices.

The invention also aims to provide the preparation method of the intrinsic high-dielectric low-loss polyimide, which has the advantages of simple preparation process and low requirements on experimental environment and conditions and can be applied to industrial large-scale production.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a diamine monomer, the molecular structure general formula of which is as follows:

wherein R is₁is-NH₂or-Ph-NH₂，R₂、R₃Is a substituent containing a sulfone group structure or-H.

The invention provides intrinsic high-dielectric low-loss polyimide containing the diamine monomer, which has a molecular structure general formula as follows:

wherein: m and n represent polymerization degree, m/n is 1/99-100/0, wherein Y₁In the case of homopolymerization, i.e., n is 0; x₁、X₂Is a tetravalent aromatic or aliphatic hydrocarbon radical, Y₂Is a diamine residue, Y₁Is the diamineA monomer.

Preferably, said R is₂、R₃One or two of which are selected from one of the following structural formulas:

wherein p, q and t are more than or equal to 0.

Preferably, said X₁、X₂Identical or different, X₁、X₂A tetravalent aromatic or aliphatic hydrocarbon group, preferably selected from the following structures:

preferably, said Y is₂Is a diamine residue, preferably selected from the following structures:

the invention provides a preparation method of the intrinsic high-dielectric low-loss polyimide, which comprises the following steps: in an inert argon or nitrogen atmosphere, will have Y₁Diamine monomer of structure (I) or having Y₁And Y₂Mixed diamine monomers of structure with X₁Dianhydride monomer of structure X₁And X₂Mixed diamine monomers of structure (I) are mixed according to a molar ratio of 1: (0.9-1.1) dissolving in an aprotic polar organic solvent, stirring and reacting for 24-72 h at normal temperature to obtain a homogeneous transparent polyamic acid glue solution, and performing dehydration and imidization to obtain the intrinsic high-dielectric low-loss polyimide.

Preferably, the intrinsic type high-dielectric low-loss polyimide is a powder material or a film material.

Preferably, containing Y₁Diamine monomer of structure (II) or containing Y₁Structure and Y₂Mixed diamine monomers of structure and containing X₁Dianhydride monomer of structure or containing X₁Structure and X₂The sum of the mass of the mixed dianhydride monomers with the structure is 1 to 50 percent of the mass of the used reaction solvent.

Preferably, the aprotic polar organic solvent is one or a mixture of two or more selected from N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, dimethyl sulfone, sulfolane and m-cresol.

Preferably, the method for forming polyimide by dehydrating and imidizing the polyamic acid glue solution is thermal imidization or chemical imidization.

Preferably, the step of thermal imidization is: the polyamic acid solution is spread on a glass plate or spin-coated on ITO glass, and heated up for thermal imidization, wherein the temperature raising procedure is as follows: heating the room temperature to 50-100 ℃, and keeping the temperature for 10-60 min; then heating to 120-180 ℃, and keeping the temperature for 10-60 min; then heating to 200-250 ℃, and keeping the temperature for 10-60 min; and finally, heating to 260-300 ℃, and cooling to obtain the polyimide film.

Preferably, the chemical imidization process comprises the steps of: adding a dehydrating agent into polyamic acid, stirring for 12-48 h, pouring the solution into methanol, filtering, precipitating and drying to obtain polyimide powder; dissolving polyimide powder in one or more than two mixed solvents of N, N-dimethylformamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, dimethyl sulfone, sulfolane and m-cresol, heating until the polyimide powder is completely dissolved, coating a polyimide glue solution on a glass plate or spin-coating the polyimide glue solution on ITO glass, heating to 150-280 ℃, drying to remove the solvent, and cooling to obtain the polyimide film.

For containing Y₁The diamine with the structure can be synthesized by a series of reactions such as halogenation, nucleophilic substitution, Suzuki and the like according to the actual needed specific molecular structure by designing a synthetic route by a person skilled in the art, and for example, the method can comprise the following steps: (1) carrying out halogenation reaction on dibromotoluene and N-bromosuccinimide to obtain a dibromomethylbromobenzene compound; (2) carrying out nucleophilic substitution reaction on a dibromomethylbromobenzene compound and sodium methanesulfinate to obtain a dibromobenzene compound with a sulfone group; (3) dibromo-benzene compound with sulfone group and pAnd (3) carrying out Suzuki reaction on the aminophenylboronic acid to obtain the diamine monomer with the sulfone group.

The invention also provides application of the intrinsic high-dielectric low-loss polyimide in the field of high-capacitance energy storage materials or photoelectric devices.

The invention discloses the following technical effects:

the polar group sulfone group is introduced into the polyimide, so that the dipole moment of the material can be obviously improved, and the high-dielectric polyimide material can be obtained. Due to the existence of the large dipole moment sulfuryl side chain, the side chain can be oriented to a certain degree under the action of an electric field, so that the dielectric constant of the material is improved. Meanwhile, the prepared polyimide film has a series of advantages of low dielectric loss, excellent thermal stability and the like. The invention has wide applicability and simple and various preparation methods, thereby being applicable to large-scale industrial production. The polyimide can be used for preparing high dielectric materials, is widely applied to high and new technical fields such as energy storage, photoelectric devices, information industry and the like, and is particularly applied to the aspect of organic field effect transistors.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

FIG. 1 is an infrared spectrum of three polyimides obtained in examples 1 to 3 of the present invention;

FIG. 2 is a graph showing the thermogravimetric curves of three polyimides obtained in examples 1 to 3 of the present invention;

FIG. 3 is a graph of dielectric constant versus frequency for three polyimides prepared in examples 1-3 of the present invention.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

Example 1

15g (60.02mmol) of 3, 5-dibromotoluene, 10.68g (60.02mmol) of N-bromosuccinimide, and 0.49g of azobisisobutyronitrile (3mmol) were dissolved in 180mL of acetonitrile, and the mixture was heated to 85 ℃ under argon atmosphere and refluxed for 3 hours. And (4) carrying out petroleum ether column chromatography to obtain a target product 3, 5-dibromo benzyl bromide.¹H NMR(400MHz,DMSO–d₆)δ7.80(t,J＝1.7Hz,1H),7.72(d,J＝1.7Hz,2H),4.68(s,2H)。

10g (30.41mmol) of 3, 5-dibromobenzyl bromide and 7.49g (73.32mmol) are added into 75mL of DMF, reacted at 60 ℃ for 3 hours, poured into 1000mL of saturated aqueous sodium chloride solution to precipitate a white solid, and dried to obtain the target product 1, 3-dibromo-5 (methylsulfonylmethyl) benzene.¹H NMR(400MHz,DMSO–d₆)δ7.90(t,J＝1.8Hz,1H),7.66(d,J＝1.8Hz,2H),4.55(s,2H),2.96(s,3H)。

4g (12.19mmol) of 1, 3-dibromo-5 (methylsulfonylmethyl) benzene, 5.08g (36.58mmol, 2.4eq) of p-aminobenzeneboronic acid hydrochloride, 33mL of 2M K₂CO₃Solution, catalytic amount of Pd (PPh)₃)₄Add to 65mL THF. The reaction was carried out at 70 ℃ for 48 h. After column chromatography, the target product 5 ' - (methylsulfonylmethyl) - (1,1 ': 3 ', 1 ' -triphenyl) -4,4 ' -diamine (m, m-MSMDA) is obtained.¹H NMR(400MHz,DMSO–d₆)δ7.65(t,J＝1.7Hz,1H),7.48–7.35(m,6H),6.73–6.60(m,4H),5.26(s,4H),4.52(s,2H),2.94(s,3H)。

The molecular structural formula of the monomer m, m-MSMDA in the embodiment is as follows:

3.52g (0.01mol) of m, m-MSMDA and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 2.18g (0.01mol) of 1,2,4, 5-pyromellitic dianhydride (PMDA) was added and reacted overnight to obtain a homogeneous transparent viscous polyamic acid (PAA) solution. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, cooling, and taking out the polyimide film, wherein the mark is m, m-MSMPM.

The molecular structural formula of the high dielectric polyimide m, m-MSMPM film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 2

15g (60.02mmol) of 2, 5-dibromotoluene, 10.68g (60.02mmol) of N-bromosuccinimide, 0.49g of azobisisobutyronitrile (3mmol) were dissolved in 180mL of acetonitrile and heated to 85 ℃ under argon atmosphere for reflux for 3 h. And (4) carrying out petroleum ether column chromatography to obtain a target product 2, 5-dibromo benzyl bromide.

10g (30.41mmol) of 2, 5-dibromobenzyl bromide and 7.49g (73.32mmol) are added into 75mL of DMF, reacted at 60 ℃ for 3 hours, poured into 1000mL of saturated aqueous sodium chloride solution to precipitate a white solid, and dried to obtain the target product 1, 4-dibromo-2- (methylsulfonylmethyl) benzene.

4g (12.19mmol) of 1, 4-dibromo-2- (methylsulfonylmethyl) benzene, 5.08g (36.58mmol, 2.4eq) of p-aminobenzeneboronic acid hydrochloride, 33mL of 2M K₂CO₃Solution, catalytic amount of Pd (PPh)₃)₄Add to 65mL THF. The reaction was carried out at 70 ℃ for 48 h. After column chromatography, the target product 2 ' - (methylsulfonylmethyl) - (1,1 ': 4 ', 1 ' -triphenyl) -4,4 ' -diamine (m, o-MSMDA) is obtained.

The molecular structural formula of the monomer m, o-MSMDA in the example is as follows:

3.52g (0.01mol) of m, o-MSMDA and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 2.18g (0.01mol) of 1,2,4, 5-pyromellitic dianhydride (PMDA) was added and reacted overnight to obtain a homogeneous transparent viscous polyamic acid (PAA) solution. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide m, o-MSMPM film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 3

15g (60.02mmol) of 2, 6-dibromotoluene, 10.68g (60.02mmol) of N-bromosuccinimide, and 0.49g of azobisisobutyronitrile (3mmol) were dissolved in 180mL of acetonitrile, and the mixture was heated to 85 ℃ under argon atmosphere and refluxed for 3 hours. And (4) carrying out petroleum ether column chromatography to obtain a target product 2, 5-dibromo benzyl bromide.

10g (30.41mmol) of 2, 6-dibromobenzyl bromide and 7.49g (73.32mmol) are added into 75mL of DMF, reacted at 60 ℃ for 3 hours, poured into 1000mL of saturated aqueous sodium chloride solution to precipitate a white solid, and dried to obtain the target product 1, 3-dibromo-2- (methylsulfonylmethyl) benzene.

4g (12.19mmol) of 1, 3-dibromo-2- (methylsulfonylmethyl) benzene, 5.08g (36.58mmol, 2.4eq) of p-aminobenzeneboronic acid hydrochloride, 33mL of 2M K₂CO₃Solution, catalytic amount of Pd (PPh)₃)₄Add to 65mL THF. The reaction was carried out at 70 ℃ for 48 h. After column chromatography, the target product 2 ' - (methylsulfonylmethyl) - (1,1 ': 3 ', 1 ' -triphenyl) -4,4 ' -diamine (o, o-MSMDA) is obtained.

The molecular structural formula of the monomer o, o-MSMDA in this example is as follows:

3.52g (0.01mol) of o, o-MSMDA and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 2.18g (0.01mol) of 1,2,4, 5-pyromellitic dianhydride (PMDA) was added and reacted overnight to obtain a homogeneous transparent viscous polyamic acid (PAA) solution. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide o, o-MSMPM film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 4

3.52g (0.01mol) of m, m-MSMDA (prepared in example 1) and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 3.22g (0.01mol) of 3,3 ', 4, 4' -benzophenonetetracarboxylic dianhydride (BTDA) was added and reacted overnight to give a homogeneous, transparent and viscous polyamic acid (PAA) dope. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide m, m-MSMBT film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 5

3.52g (0.01mol) of m, o-MSMDA (prepared in example 2) and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 3.22g (0.01mol) of 3,3 ', 4, 4' -benzophenonetetracarboxylic dianhydride (BTDA) was added and reacted overnight to give a homogeneous, transparent and viscous polyamic acid (PAA) dope. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide m, o-MSMBT film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 6

3.52g (0.01mol) of o, o-MSMDA (prepared in example 3) and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 3.22g (0.01mol) of 3,3 ', 4, 4' -benzophenonetetracarboxylic dianhydride (BTDA) was added and reacted overnight to give a homogeneous, transparent and viscous polyamic acid (PAA) dope. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide o, o-MSMBT film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 7

3.52g (0.01mol) of m, m-MSMDA (prepared in example 1) and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 3.58g (0.01mol) of 3,3 ', 4, 4' -diphenylsulfonetetracarboxylic dianhydride (DSDA) was added and reacted overnight to give a homogeneous, transparent and viscous polyamic acid (PAA) dope. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide m, m-MSMDS film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 8

3.52g (0.01mol) of m, o-MSMDA (prepared in example 2) and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 3.58g (0.01mol) of 3,3 ', 4, 4' -diphenylsulfone tetracarboxylic dianhydride (DSDA) was added and reacted overnight to give a homogeneous, transparent and viscous polyamic acid (PAA) dope. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide m, o-MSMDS film in the embodiment is as follows:

wherein n is more than or equal to 100.

Example 9

3.52g (0.01mol) of o, o-MSMDA (prepared in example 3) and 10mL of N, N-dimethylformamide were added to a 50mL single-neck flask at room temperature, stirred until completely dissolved, and 3.58g (0.01mol) of 3,3 ', 4, 4' -diphenylsulfone tetracarboxylic dianhydride (DSDA) was added and reacted overnight to give a homogeneous, transparent and viscous polyamic acid (PAA) dope. The PAA glue solution is coated on a glass plate by scraping, and is placed in a vacuum oven to be vacuumized, and the temperature rising procedure is as follows: heating the room temperature to 80 ℃, and keeping the temperature for 1 h; then raising the temperature from 80 ℃ to 150 ℃, and keeping the temperature for 1 h; then heating to 250 ℃, and keeping the temperature for 1 h; and finally, heating to 300 ℃, keeping the temperature for 1h, and taking out the polyimide film after cooling.

The molecular structural formula of the high dielectric polyimide o, o-MSMDS film in the embodiment is as follows:

wherein n is more than or equal to 100.

The IR spectrum of the three polyimides obtained in examples 1 to 3 is shown in FIG. 1, from which it can be seen that 1776cm^-1And 1717cm^-1The peak position of the asymmetric and symmetric stretching vibration of the C ═ O bond in the imide ring appears, 1358cm^-1The position is the characteristic peak position of C-N stretching vibration.

The thermal weight loss curves of the three polyimides in examples 1-3 are shown in FIG. 2, and it can be seen from FIG. 2 that the 5% thermal weight loss temperature of m, m-MSMPM is 465 ℃, the 5% thermal weight loss temperature of m, o-MSMPM is 438 ℃, and the 5% thermal weight loss temperature of o-MSMPM is 454 ℃.

The graph of dielectric constant versus frequency for the three polyimides of examples 1-3 is shown in FIG. 3, and it can be seen from FIG. 3 that the dielectric constant of m, m-MSMPM is 6.0, the dielectric constant of m, o-MSMPM is 5.4, and the dielectric constant of o, o-MSMPM is 4.9 at 100 Hz.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.