阅读说明：本技术 一种聚乙酰氨基酰亚胺单体、其制备方法及其应用 (Polyacetamido imide monomer, preparation method and application thereof ) 是由 侯豪情 胡昭宇 胡添 王科遇 于 2021-04-16 设计创作，主要内容包括：本发明涉及化合物的合成技术领域,具体涉及到一种聚乙酰氨基酰亚胺单体、其制备方法及其应用。本发明的聚乙酰氨基酰亚胺单体含双隐形氨基的四元胺化合物结构,其中取代基R-(1)和取代基R-(2)分别独立地为氢原子或乙酰氨基。此外,本发明中通过对聚乙酰氨基酰亚胺单体的结构进行设计,使之具备隐形的氨基,这种含隐形氨基的四元胺单体,将敏感的四氨基单体转变为二氨基单体,将难溶的高性能聚吡咙的合成拆成了两步合成,有助于制备得到高性能的聚吡咙薄膜、高强高模聚吡咙纤维和高耐温聚吡咙纳米纤维等功能化产品。此外,本发明中通过对乙酸酐与取代联苯二胺的摩尔比例,反应体系的温度以及乙酐稀溶液的滴加速度的控制,实现更高的收率和高的纯度。(The invention relates to the technical field of compound synthesis, in particular to a polyacetylaminoimide monomer, a preparation method and application thereof. The polyacetylaminoimide monomer of the invention contains a quaternary amine compound structure with double stealth amino groups, wherein a substituent R 1 And a substituent R 2 Each independently a hydrogen atom or an acetamido group. In addition, the structure of the polyacetylaminoimide monomer is designed to have invisible amino, and the tetraamine monomer containing the invisible amino converts sensitive tetraamino monomer into diamino monomer to convert sensitive tetraamino monomerThe synthesis of the indissolvable high-performance polypyrrolone is separated into two-step synthesis, and the preparation of functional products such as a high-performance polypyrrolone film, high-strength high-modulus polypyrrolone fiber and high-temperature-resistant polypyrrolone nanofiber is facilitated. In addition, the invention realizes higher yield and high purity by controlling the molar ratio of the acetic anhydride to the substituted biphenyldiamine, the temperature of the reaction system and the dropping speed of the acetic anhydride dilute solution.)

1. A polyacetylaminoimide monomer, characterized in that it has the following structure

Wherein the substituent R₁And a substituent R₂Each independently a hydrogen atom or an acetamido group.

2. The polyacetylaminoimide monomer of claim 1, wherein the substituent R is₁And a substituent R₂The same; preferably, the substituent R₁And a substituent R₂Is an acetylamino group.

3. A polyacetylaminoimide monomer according to claim 2, characterized in that it has the following structure:

4. a process for preparing a polyacetylaminoimide monomer according to any one of claims 1 to 3, characterized in that it comprises the steps of:

(1) dissolving acetic anhydride in an organic solvent A to obtain a reaction material A, adding the reaction material A into a solution B of an organic solvent for substituting diphenyldiamine, and reacting at a reaction temperature of not higher than 5 ℃ for 1-3 hours to obtain an intermediate product;

(2) adding calcium oxide into the intermediate product for precipitation, filtering and concentrating to obtain a crude product;

(3) recrystallizing the crude product to obtain the polyacetylaminoimide monomer.

5. The method for preparing a polyacetylaminoimide monomer according to claim 4, wherein the molar ratio of the acetic anhydride to the substituted biphenyldiamine in step (1) is 1: (1.8-2.2).

6. The method for preparing a polyacetylaminoimide monomer according to claim 4, wherein the reaction temperature in step (1) is-5 to 0 ℃.

7. The method for preparing the polyacetylaminoimide monomer according to claim 4, wherein the dropping rate of the reactant A into the solution B of the substituted biphenyldiamine in the organic solvent is 1 to 3 mL/min.

8. The method for preparing a polyacetylaminoimide monomer according to claim 4, wherein the solvent used for the recrystallization in the step (3) is a mixed solvent of ethanol and tetrahydrofuran; preferably, the volume ratio of ethanol to tetrahydrofuran is 1: 1.

9. The method for producing a polyacetylaminoimide monomer according to claim 4, wherein the organic solvent A and the organic solvent B in step (1) are the same.

10. The application of the polyacetylaminoimide monomer prepared by the preparation method according to any one of claims 4 to 9, which is characterized in that the polyacetylaminoimide monomer is applied to the field of polyimide products and polypyrrolone products.

Technical Field

The invention relates to the technical field of compound synthesis, in particular to a polyacetylaminoimide monomer, a preparation method and application thereof.

Background

Polyimide is an aromatic heterocyclic polymer compound containing imide group chain segments in the molecular structure, and is one of the varieties with good heat resistance in the prior engineering plastics. Polyimide is used as a special engineering plastic and is widely applied to the technical fields of aviation, aerospace, microelectronics, nano-scale, liquid crystal, separation membranes, laser and the like. Polyimides can be classified into pyromellitic polyimides, soluble polyimides, polyamide-imides, and polyetherimides, and are mainly prepared by a series of thermal condensation reactions between monomers such as polyamines (e.g., p-phenylenediamine) and polyacids (anhydrides). However, the conventional polyamine monomers have fewer types and single functions, and do not contribute much to the specific overall performance and functionalization of the polyimide. And a plurality of side reactions exist in the preparation process of some polyamine monomers with specific structures, and the preparation of high-purity and high-yield polyamine with specific structures as a polyimide monomer has great difficulty.

In addition, polypyrrolone is a rigid trapezoidal or semi-trapezoidal polyaromatic heterocyclic macromolecular polymer, has good high temperature resistance and oxidation resistance, and can be widely applied in a plurality of fields. They are obtained by subjecting a tetraamine and a dianhydride to a series of high-temperature condensation reactions in a high-boiling solvent such as polyphosphoric acid or methanesulfonic acid. The polypyrrolone material thus obtained is insoluble or insoluble in common organic solvents, and thus is difficult to process into films and spinning, especially electrospinning. Therefore, a quaternary amine monomer containing an invisible diamino group (such as acetamido) is very much developed for the preparation of polyimide or polypyrrolone products.

Disclosure of Invention

In view of the above technical problems, a first aspect of the present invention provides a polyacetylaminoimide monomer having the following structure

Wherein the substituent R₁And a substituent R₂Each independently a hydrogen atom or an acetamido group.

As a preferred embodiment of the present invention, the substituent R is₁And a substituent R₂The same; preferably, the substituent R₁And a substituent R₂Is an acetylamino group.

As a preferable technical scheme, the invention has the following structure:

a second aspect of the present invention provides a method for preparing the above-mentioned polyacetylaminoimide monomer, which comprises the steps of:

(1) dissolving acetic anhydride in an organic solvent A to obtain a reaction material A, adding the reaction material A into a solution B of an organic solvent for substituting diphenyldiamine, and reacting at a reaction temperature of not higher than 5 ℃ for 1-3 hours to obtain an intermediate product;

(2) adding calcium oxide into the intermediate product for precipitation, filtering and concentrating to obtain a crude product;

(3) recrystallizing the crude product to obtain the polyacetylaminoimide monomer.

As a preferable technical scheme of the invention, the molar ratio of the acetic anhydride to the substituted biphenyldiamine in the step (1) is 1: (1.8-2.2).

As a preferable technical scheme of the invention, the reaction temperature in the step (1) is-5-0 ℃.

As a preferable technical scheme, the dropping speed of the reaction material A into the organic solvent B solution of the substituted biphenyldiamine is 1-3 mL/min.

As a preferred technical scheme of the present invention, a solvent adopted in the recrystallization in the step (3) is a mixed solvent of ethanol and tetrahydrofuran; preferably, the volume ratio of ethanol to tetrahydrofuran is 1: 1.

In a preferred embodiment of the present invention, the organic solvent a and the organic solvent B in step (1) are the same.

The third aspect of the invention provides the application of the polyacetylaminoimide monomer prepared by the preparation method, which is applied to the fields of polyimide products and polypyrrolone products.

Has the advantages that: according to the invention, the structure of the polyacetylaminoimide monomer is designed to enable the polyacetylaminoimide monomer to have invisible amino, the tetraamine monomer containing the invisible amino converts sensitive tetraamino monomer into diamino monomer, and the synthesis of insoluble high-performance polypyrrolone is disassembled into two-step synthesis, so that the preparation of functional products such as high-performance polypyrrolone film, high-strength high-modulus polypyrrolone fiber and high-temperature-resistant polypyrrolone nanofiber is facilitated. In addition, the invention strictly controls the molar ratio of acetic anhydride and substituted biphenyldiamine, and also strictly controls the temperature of a reaction system (the reaction temperature is below 0 ℃), controls the reaction activity and ensures that only amino with higher activity on the para position reacts with acetic anhydride; the dripping speed of the acetic anhydride dilute solution is controlled, the number of amino compound molecules in a reaction system is ensured to be far higher than that of acetic anhydride molecules, and the occurrence of side reaction is controlled, so that higher yield and higher purity are realized.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of 3,3 '-diamino-4, 4' -diacetamidobiphenyl of example 1 of the present application.

FIG. 2 is an infrared spectrum of 3,3 '-diamino-4, 4' -diacetoxybiphenyl as in example 1 of the present application.

Detailed Description

The technical features of the technical solutions provided by the present invention will be further clearly and completely described below with reference to the specific embodiments, and it should be apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The words "preferred", "preferably", "more preferred", and the like, in the present invention, refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

It should be understood that other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

In a first aspect, the present invention provides a polyacetylaminoimide monomer having the structure

Wherein the substituent R₁And a substituent R₂Each independently a hydrogen atom or an acetamido group.

The amino group in the polyacetylaminoimide monomer of the invention may be the same substituent R on any of the 2-position, 3-position or 4-position carbon atoms₁And a substituent R₂Or on any of the carbon atoms in positions 2, 3 and 4. Preferably, the substituent R₁And a substituent R₂Each independently a hydrogen atom or an acetamido group. Wherein the substituent R₁And a substituent R₂May be the same substituent or may be the same substituentAre different substituents.

In some embodiments, the substituent R is₁And a substituent R₂The same; further preferably, the substituent R₁And a substituent R₂Is an acetylamino group.

In some preferred embodiments, the amino group in the polyacetylaminoimide monomer is substituted with the carbon atom at position 3 and the acetamido group is substituted with the carbon atom at position 4, having the structure:

a second aspect of the present invention provides a method for preparing the above-mentioned polyacetylaminoimide monomer, which comprises the steps of:

(1) dissolving acetic anhydride in an organic solvent A to obtain a reaction material A, adding the reaction material A into a solution B of an organic solvent for substituting diphenyldiamine, and reacting at a reaction temperature of not higher than 5 ℃ for 1-3 hours to obtain an intermediate product;

(2) adding calcium oxide into the intermediate product for precipitation, filtering and concentrating to obtain a crude product;

(3) recrystallizing the crude product to obtain the polyacetylaminoimide monomer.

In the present invention, the specific types of the organic solvent a and the organic solvent B are not particularly limited, and various organic solvents capable of dissolving acetic anhydride, which are well known to those skilled in the art, may be selected, including but not limited to tetrahydrofuran, ethylene glycol dimethyl ether, methyl carbonate, dimethyl sulfoxide, DMF, DMAc, and the like. In some preferred embodiments, the organic solvent a and the organic solvent B in step (1) are the same; further preferably, the organic solvent a and the organic solvent B are tetrahydrofuran.

In some embodiments, the molar ratio of acetic anhydride to substituted biphenyldiamine in step (1) is 1: (1.8-2.2); further preferably, the molar ratio is 1: 2.

The substituted benzidine in the invention is benzidine substituted by carboxyl, hydroxyl, amino, cyano, halogen and other groups, preferably, the substituted benzidine is benzidine substituted by amino, and more preferably, the benzidine substituted by amino is 3, 3' -diaminobenzidine.

In the invention, the reaction temperature between the acetic anhydride and the substituted biphenyldiamine is not higher than 5 ℃, and is further preferably-5 to 0 ℃. The structure of the amino substituted benzidine contains four amino groups, and the reaction activity between the amino group at the para position and acetic anhydride is the highest. Therefore, on the premise of ensuring the raw material ratio, the reaction temperature is controlled to be lower than 0 ℃, so that the reaction of acetic anhydride is ensured to only occur with para-amino, the reaction with 3 rd amino is avoided, and the generation of byproducts is avoided.

In the invention, substituted biphenyldiamine is dissolved in an organic solvent B to prepare a solution with the weight percent of 10-20, acetic anhydride is prepared into a solution with the weight percent of 5-15, and the solution of the acetic anhydride is added into the solution of the substituted biphenyldiamine for reaction. In some preferred embodiments, the dropping speed of the reactant A into the organic solvent B solution of substituted biphenyldiamine is 1-3 mL/min.

In the invention, a proper amount of calcium oxide is added into the reaction product in the step (1), so that acetic anhydride in the system forms calcium acetate precipitate, unreacted acetic anhydride in the system is removed by filtration, and then the filtrate is concentrated by rotary evaporation and other modes, and the solvent in the filtrate is removed to obtain a crude product. The crude product obtained is further purified by recrystallization. The recrystallization step is not particularly limited in the present invention, and may be performed according to a manner known to those skilled in the art. In some preferred embodiments, the solvent used for recrystallization in step (3) is a mixed solvent of ethanol and tetrahydrofuran; preferably, the volume ratio of ethanol to tetrahydrofuran is 1: 1.

The third aspect of the invention provides the application of the polyacetylaminoimide monomer prepared by the preparation method, which is applied to the fields of polyimide products and polypyrrolone products.

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

Example 1

15 g of 3,3 '-diaminobenzidine (CAS: 91-95-2) is placed in a reactor and 85g of THF is added to dissolve the 3, 3' -diaminobenzidine (CAS: 91-95-2) to prepare a solution with the concentration of 15 wt%, then 10 wt% of acetic anhydride THF solution is added dropwise into the 3,3 '-diaminobenzidine (M ═ 214.27) solution at the speed of 2mL/min (the molar ratio of 3, 3' -diaminobenzidine to acetic anhydride (M ═ 102.09) is ensured to be 1: 2), and the reaction temperature is controlled within the range of-5 ℃ to 0 ℃ to react for 2 hours to obtain the crude product of 3,3 '-diamino-4, 4' -diacetamido biphenyl. Adding a proper amount of calcium oxide into the crude product to form calcium acetate precipitate, and filtering to remove the calcium acetate in the system; the filtrate was then concentrated by rotary evaporation to give 20.5 g (theoretical yield 20.88 g) of a crude product of 3,3 '-diamino-4, 4' -diacetamidobiphenyl (M ═ 298.27); the crude 3,3 '-diamino-4, 4' -acetamidobiphenyl was added with 1/1 vol% ethanol/THF solvent and recrystallized to give 19.6 g of 99% pure 3,3 '-diamino-4, 4' -diacetamidobiphenyl with a final yield of 93.9%. As can be seen from the nuclear magnetic hydrogen spectrum and the infrared spectrum of fig. 1 and fig. 2, the quaternary amine compound 3,3 '-diamino-4, 4' -diacetamido biphenyl containing double stealth amino groups is prepared, and the spectrogram does not contain obvious hetero peaks, and further proves that the purity is high and almost no by-product is generated.

Comparative example 1

15 g of 3,3 ' -diaminobenzidine (CAS: 91-95-2) is placed in a reactor and 85g of THF is added to dissolve the 3,3 ' -diaminobenzidine to prepare a solution with the concentration of 15 wt%, then 143 g of 10 wt% acetic anhydride THF solution is added into the 3,3 ' -diaminobenzidine THF solution at one time, and the reaction temperature is controlled within the range of-5 ℃ to 0 ℃ to react for 2 hours to obtain a crude product of 3,3 ' -diamino-4, 4 ' -diacetamido biphenyl (M ═ 298.27). Adding a proper amount of calcium oxide into the crude product to form calcium acetate precipitate, and filtering to remove acetic acid in the system; then, carrying out rotary evaporation and concentration on the filtrate to obtain a crude product of the 3,3 '-diamino-4, 4' -diacetamidobiphenyl; ethanol/THF solvent was added to the crude 3,3 '-diamino-4, 4' -diacetoxybiphenyl product in a volume ratio of 1:1, and recrystallization was carried out to obtain 14.5 g of 3,3 '-diamino-4, 4' -diacetoxybiphenyl product with a purity of 95%, with a final yield of 69.4%.

Comparative example 2

3,3 ' -diaminobenzidine (CAS: 91-95-2) is placed in a reactor and added with THF for dissolving to prepare a solution with the concentration of 15 wt%, then 10 wt% THF solution of acetic anhydride is added dropwise into the THF solution of the 3,3 ' -diaminobenzidine at the speed of 2mL/min (ensuring that the molar ratio of the 3,3 ' -diaminobenzidine and the acetic anhydride is X1: Y1), and the reaction temperature is controlled at about 15 ℃ for 2 hours to obtain the crude product of the 3,3 ' -diamino-4, 4 ' -diacetyl biphenyl (M ═ 298.27). Adding a proper amount of calcium oxide into the crude product to form calcium acetate precipitate, and filtering to remove acetic acid in the system; then, carrying out rotary evaporation and concentration on the filtrate to obtain a crude product of the 3,3 '-diamino-4, 4' -diacetamidobiphenyl; the crude product of 3,3 '-diamino-4, 4' -diacetoxybiphenyl was added with ethanol/THF solvent in a volume ratio of 1:1, and recrystallized to obtain a 96% purity product of 3,3 '-diamino-4, 4' -diacetoxybiphenyl in a final yield of 85.6%.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms, and any person skilled in the art may modify or change the technical content disclosed above into an equivalent embodiment with equivalent changes, but all those simple modifications, equivalent changes and modifications made on the above embodiment according to the technical spirit of the present invention still belong to the protection scope of the present invention.