阅读说明：本技术 一种交联型聚芳醚腈耐高温介电薄膜的制备方法 (Preparation method of crosslinking type poly (arylene ether nitrile) high-temperature-resistant dielectric film ) 是由 黄宇敏 开媛 林健 刘孝波 于 2019-09-23 设计创作，主要内容包括：本发明涉及一种交联型聚芳醚腈的合成方法及其耐高温介电薄膜的制备方法,属于特种高分子材料领域。此类聚芳醚腈主要分子结构设计出发,通过将侧链含氨基的对苯二酚作为反应单体之一,合成羟基封端的聚芳醚腈,然后在分子主链末端引入邻苯二甲腈合成可交联型聚芳醚腈。采用流延成膜和低温自交联策略可得到交联型聚芳醚腈薄膜。所得到的薄膜具有优异的热性能、力学性能和介电性能,可作为耐高温介电薄膜使用。本发明的制备方法简单且易于工业化操作,可扩宽聚芳醚腈的应用范围。(The invention relates to a method for synthesizing cross-linked poly (arylene ether nitrile) and a method for preparing a high-temperature-resistant dielectric film thereof, belonging to the field of special high polymer materials. The main molecular structure of the polyaryl ether nitrile is designed, hydroquinone with amino on a side chain is used as one of reaction monomers to synthesize hydroxyl-terminated polyaryl ether nitrile, and then phthalonitrile is introduced into the tail end of a molecular main chain to synthesize the crosslinkable polyaryl ether nitrile. The crosslinked poly (arylene ether nitrile) film can be obtained by adopting a tape casting film forming and low-temperature self-crosslinking strategy. The obtained film has excellent thermal property, mechanical property and dielectric property, and can be used as a high-temperature-resistant dielectric film. The preparation method is simple and easy for industrial operation, and can widen the application range of the poly (arylene ether nitrile).)

1. A crosslinked polyarylene ether nitrile is characterized in that the polyarylene ether nitrile contains amino side groups and is terminated with phthalonitrile, and the structural formula of the crosslinked polyarylene ether nitrile is as follows:

wherein x is 0.05-1, -Ar-is a dihydric phenol having the following structure, but not limited to:

2. a method for synthesizing cross-linked poly (arylene ether nitrile), which is characterized by comprising the following steps: adding a certain amount of potassium carbonate, dihydric phenol and 4-aminophenyl hydroquinone into a reaction bottle, taking a polar solvent (such as N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, N-dimethylformamide and the like) as a solvent, and taking methylbenzene as a water-carrying agent, wherein the molar ratio of the total dihydric phenol to the potassium carbonate is 1: (1.2-1.5), the volume ratio of the solvent to the toluene is (1-2): 1; heating the reaction at the temperature of 120-130 ℃ for reflux for 2h, then removing water generated in the reaction, and controlling the reaction temperature to be between 130-140 ℃; and then adding 2, 6-dichlorobenzonitrile into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then increasing the temperature to 170 ℃ in a gradient manner for about 2h, maintaining the reaction at about 170 ℃ until the reaction system reaches the maximum viscosity and does not increase, wherein the molar ratio of the 2, 6-dichlorobenzonitrile to the total dihydric phenol is 1: (1.02-1.05); reducing the temperature of the system to about 100-120 ℃, adding 4-nitrophthalonitrile, potassium carbonate and N-methylpyrrolidone, and then continuing to react for 3-5 h, wherein the molar ratio of 4-nitrophthalonitrile, potassium carbonate and 2, 6-dichlorobenzonitrile is (0.02-0.05): (0.02-0.05): pouring the obtained crude product into acetone, filtering and crushing, respectively washing with acetone, ethanol, dilute hydrochloric acid and water for 3-5 times, and drying in a vacuum oven to obtain a crosslinkable polyarylether nitrile refined product, wherein the synthesis steps are shown as the following formula:

3. a method for producing a crosslinked polyarylene ether nitrile film, characterized in that the polyarylene ether nitrile film having the structure of claim 1 is produced by a casting film-forming method and the crosslinked polyarylene ether nitrile film is obtained by thermal crosslinking autocatalytically with side-chain amino groups.

4. A crosslinked polyarylene ether nitrile film, which is characterized in that: the series of poly (arylene ether nitrile) has good heat resistance and mechanical property, the glass transition temperature of the poly (arylene ether nitrile) can reach more than 330 ℃, the initial decomposition temperature of the poly (arylene ether nitrile) can reach more than 490 ℃, and the tensile strength of the poly (arylene ether nitrile) can reach more than 90 MPa. Meanwhile, the dielectric constant of the film is 2.72-3.80 under 1kHz, the dielectric loss is 0.03-0.06, and the film can be used as a high-temperature-resistant dielectric film.

Technical Field

The invention relates to a method for synthesizing cross-linked poly (arylene ether nitrile) and a method for preparing a high-temperature-resistant dielectric film thereof, belonging to the field of special high polymer materials. The cross-linked poly (arylene ether nitrile) can be used as a high-temperature-resistant dielectric film.

Background

Polyarylether nitrile (PEN) is a polyarylether with side chain containing cyanoA compound (I) is provided. As a special thermoplastic resin, the thermoplastic resin has attracted much attention because of its advantages of high temperature resistance, chemical corrosion resistance, high strength and modulus, easy molding and processing, etc. Compared with poly (arylene ether nitrile) and poly (arylene ether ketone) and poly (arylene ether sulfone), due to the introduction of a cyano functional group on a molecular side chain, the poly (arylene ether nitrile) has excellent heat resistance and mechanical property and also has more excellent processing property, and more importantly, the cyano group on the side chain can be used as a potential crosslinking group to further improve the heat resistance, mechanical property and the like of the poly (arylene ether nitrile). Conventional polyarylene ether nitriles have been developed because of their glass transition temperatures (T)_g) Not high enough to significantly lower the modulus when applied above the glass transition temperature, thus resulting in lower temperatures for practical use.

The phthalonitrile-terminated poly (arylene ether nitrile) can effectively combine the advantages of thermoplastic resin and thermosetting resin by utilizing the crosslinking reaction of the terminated cyano group and the side chain cyano group, namely, the product is prepared by utilizing the easy processing and molding of the thermoplastic resin. Through the cross-linking reaction, the heat resistance, the flame retardant property, the mechanical property and the like of the flame retardant are further improved. The introduction of the end group phthalonitrile greatly increases the number of crosslinkable points, and provides guarantee for expanding the application of the polyarylether nitrile in the aspect of high temperature resistance.

The crosslinking of phthalonitrile-terminated polyarylene ether nitriles can be carried out mainly by the following three methods: firstly, transition metal and transition metal salt are used as catalysts, but the catalysts have poor dispersibility, incomplete curing is likely to be caused, and the residual metal salt also has certain influence on the performance of the product; the second method is to use organic matter containing polar groups, such as organic amine, as a catalyst, but the introduction of a small-molecule curing agent can reduce the performance of the resin to a certain extent. The third is a high temperature long time heat treatment, but this condition is too severe.

Therefore, the invention mainly introduces amino with active hydrogen into a phthalonitrile terminated poly (arylene ether nitrile) chain, and utilizes the catalytic action of the amino to realize low-temperature crosslinking to obtain a poly (arylene ether nitrile) film with good heat resistance and mechanical property, and the poly (arylene ether nitrile) film can be used as a high-temperature resistant dielectric film. Meanwhile, the polymer can also be used as a matrix, the dispersibility of the filler in the matrix can be greatly enhanced due to the existence of amino groups on the side chain of the polymer, and the application field of the poly (arylene ether nitrile) can be further widened by utilizing a low-temperature autocatalytic crosslinking strategy, so that the poly (arylene ether nitrile) can be used as a high-temperature resistant structural material and a flame retardant material to be applied to the fields of aviation, aerospace and the like.

Disclosure of Invention

The invention aims to provide a low-temperature autocatalytic crosslinking strategy aiming at the heat resistance limit of the prior poly (arylene ether nitrile), further improves the heat resistance of the poly (arylene ether nitrile), and can realize the application of the material in the field of high-temperature resistant dielectric. Specifically, based on molecular structure design, hydroquinone with amino group at side chain is used as one of reaction monomers to synthesize poly (arylene ether nitrile) with end-capped hydroxyl group, and then phthalonitrile is end-capped at the end of molecular main chain (structural formula is shown in figure 1). The crosslinking type poly (arylene ether nitrile) high-temperature resistant film is obtained through the reaction characteristic of low-temperature crosslinking of the end-capped phthalonitrile, and has excellent dielectric property.

A preparation method of a cross-linking type poly (arylene ether nitrile) film is characterized by comprising the following steps: the cross-linked polyarylether nitrile contains side groups of active amino, is terminated by phthalonitrile, and is cross-linked by a side chain amino autocatalysis method to form high-temperature-resistant structures such as phthalocyanine rings, triazine rings and the like, and the cross-linked polyarylether nitrile film is used as a high-temperature-resistant dielectric film.

The structure of the hydroquinone with the side chain containing amino is shown as the following formula:

the synthesis method of the phthalonitrile terminated polyarylether nitrile with the side chain containing amino comprises the following steps:

(1) adding a certain amount of potassium carbonate, dihydric phenol and 4-aminophenyl hydroquinone into a reaction bottle, taking a polar solvent (such as N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, N-dimethylformamide and the like) as a solvent, and taking methylbenzene as a water-carrying agent, wherein the molar ratio of the total dihydric phenol to the potassium carbonate is 1: (1.2-1.5), the volume ratio of the solvent to the toluene is (1-2): 1

(2) Heating the reaction at the temperature of 120-130 ℃ for reflux for 2h, then removing water generated in the reaction, and controlling the reaction temperature to be between 130-140 ℃;

(3) and then adding 2, 6-dichlorobenzonitrile into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then increasing the temperature to 170 ℃ in a gradient manner for about 2h, maintaining the reaction at about 170 ℃ until the reaction system reaches the maximum viscosity and does not increase, wherein the molar ratio of the 2, 6-dichlorobenzonitrile to the total dihydric phenol is 1: (1.02-1.05);

(4) reducing the temperature of the system to about 100-120 ℃, adding 4-nitrophthalonitrile, potassium carbonate and N-methylpyrrolidone, and then continuing to react for 3-5 h, wherein the molar ratio of 4-nitrophthalonitrile, potassium carbonate and 2, 6-dichlorobenzonitrile is (0.02-0.05): (0.02-0.05): 1,

(5) and pouring the obtained crude product into acetone, filtering and crushing, washing respectively for 3-5 times by using acetone, ethanol, diluted hydrochloric acid and water, and drying in a vacuum oven to obtain the crosslinkable polyarylether nitrile refined product.

The specific reaction route is shown as the following formula:

wherein x is 0.05-1, HO-Ar-OH is a dihydric phenol, and the following formula is a representative-Ar-structure, but not limited to

The preparation method of the crosslinkable polyarylether nitrile film comprises the following steps: the crosslinkable polyarylether nitrile powder is dissolved in a polar solvent (such as N-methylpyrrolidone, dimethyl sulfoxide, sulfolane, N-dimethylformamide and the like), the concentration is controlled to be 0.06-0.1 g/mL, and the crosslinkable polyarylether nitrile powder is prepared by a tape casting film forming method. In order to fully remove the solvent, the temperature of the baking oven is set to 80-2 h, 100-2 h, 120-2 h, 160-2 h and 200-2 h.

The low-temperature autocatalytic crosslinking strategy is to put the dried and formed film into an oven for heat treatment, wherein the treatment temperature is one of 250-280 ℃ for 4-8 h. Then, the film was naturally cooled to room temperature, and the sample film was peeled off from the glass plate to obtain a brown crosslinked polyarylene ether nitrile film.

The obtained crosslinked poly (arylene ether nitrile) film has excellent heat resistance and mechanical properties, the glass transition temperature of the film can reach more than 330 ℃, the initial decomposition temperature of the film can reach more than 490 ℃, and the tensile strength of the film can reach more than 90 MPa. Meanwhile, the dielectric constant of the film is 2.72-3.80 under 1kHz, the dielectric loss is 0.03-0.06, and the film can be used as a high-temperature-resistant dielectric film.

The invention has the advantages that the crosslinkable polyarylether nitrile is synthesized by using the 4-aminophenyl hydroquinone as one of the reaction monomers and the phthalonitrile as the end capping group, the heat resistance of the polyarylether nitrile is improved by the low-temperature autocatalytic crosslinking strategy, and meanwhile, the polymer has good processability and can be processed into plates, blocks, films and the like. The crosslinkable polyarylether nitrile shows good film forming property, and the polyarylether nitrile film prepared by the tape casting film forming method and the thermal crosslinking has good flexibility, and simultaneously has excellent thermal property, mechanical property and dielectric property. The preparation method is simple and easy for industrial operation, not only widens the application range of the poly (arylene ether nitrile), but also improves the performance of the poly (arylene ether nitrile) to a certain extent.

Drawings

FIG. 1 is a structural formula of a typical crosslinkable polyarylene ether nitrile.

FIG. 2 shows the state of dissolution of the crosslinked polyarylene ether nitrile film prepared by the present invention in a N-methylpyrrolidone solution.

FIG. 3 is a thermogravimetric analysis of the crosslinked polyarylene ether nitrile film (I-a) prepared according to the present invention.

FIG. 4 is a graph showing the dielectric constant and dielectric loss of the crosslinked polyarylene ether nitrile film (I-a) prepared according to the present invention.

Detailed Description

The following examples of the present invention are described in connection with the following examples, which are intended to further illustrate features and advantages of the present invention, and are not to be construed as limiting the claims in any way.

Experimental case 1:

phthalonitrile-terminated biphenyl poly (arylene ether nitrile) having amino groups in the side chains:

(1) adding potassium carbonate (0.12mol), biphenol (0.0918mol) and 4-aminophenylhydroquinone (0.0102mol) into a reaction bottle containing 50ml of dehydrating agent toluene and 75ml of N-methylpyrrolidone, heating at 130 ℃, reacting and refluxing for 2h, removing water generated by the reaction, and controlling the reaction temperature to be between 130 ℃ and 140 ℃;

(2) adding 2, 6-dichlorobenzonitrile (0.1mol) into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then slowly heating up to 170 ℃ about 2h, maintaining the reaction at 170 ℃ for 2h, and enabling the reaction system to reach the maximum viscosity;

(3) reducing the temperature of the system to 100 ℃, adding 4-nitrophthalonitrile (0.02mol), potassium carbonate (0.02mol) and N-methylpyrrolidone (30ml), and then continuing to react for 4 hours;

(4) and pouring the obtained crude product into acetone, filtering and crushing, respectively washing with acetone, ethanol, diluted hydrochloric acid and water for 3-5 times, and drying in a vacuum oven to obtain white powder, namely the biphenyl poly (arylene ether nitrile) product with the side chain containing amino and terminated by phthalonitrile, wherein the structural formula is shown as the following formula (I-a).

The preparation method of the biphenyl poly (arylene ether nitrile) film with the amino-containing phthalonitrile side chain comprises the following steps: the prepared biphenyl type polyarylene ether nitrile product (2g) was dissolved in N-methylpyrrolidone (20ml) and prepared by a cast film forming method. In order to fully remove the solvent, the temperature of the baking oven is set to 80-2 h, 100-2 h, 120-2 h, 160-2 h and 200-2 h.

The preparation method of the biphenyl crosslinking type poly (arylene ether nitrile) film comprises the following steps: and (3) continuously heating the dried and formed film for heat treatment, treating the film at 260 ℃ for 8h, naturally cooling the film to room temperature, and stripping the sample film from the glass plate to obtain the biphenyl crosslinking type poly (arylene ether nitrile) film. The film was not dissolved by prolonged standing in a room temperature solution of N-methylpyrrolidone, demonstrating the success of the crosslinking (as shown in bottle 1 in FIG. 2).

The cross-linked poly (arylene ether nitrile) has excellent heat resistance, the glass transition temperature of the cross-linked poly (arylene ether nitrile) can reach 368 ℃, the temperature when the decomposition is 5 percent can reach 538 ℃ (shown in figure 3), the tensile strength can reach 103MPa, the dielectric constant under 1kHz is 3.6, and the dielectric loss is 0.02 (shown in figure 4).

Experimental case 2:

phthalonitrile-terminated bisphenol a type polyarylene ether nitrile having an amino group in the side chain:

(1) adding potassium carbonate (0.12mol), bisphenol A (0.0918mol) and 4-aminophenylhydroquinone (0.0102mol) into a reaction bottle containing 50ml of dehydrating agent toluene and 75ml of N-methylpyrrolidone, heating at 130 ℃, reacting and refluxing for 2h, removing water generated by the reaction, and controlling the reaction temperature to be between 130 ℃ and 140 ℃;

(2) adding 2, 6-dichlorobenzonitrile (0.1mol) into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then slowly heating up to 170 ℃ about 2h, maintaining the reaction at 170 ℃ for 2h, and enabling the reaction system to reach the maximum viscosity;

(3) reducing the temperature of the system to 100 ℃, adding 4-nitrophthalonitrile (0.02mol), potassium carbonate (0.02mol) and N-methylpyrrolidone (20ml), and then continuing to react for 3 hours;

(4) and pouring the obtained crude product into acetone, filtering and crushing, respectively washing with acetone, ethanol, dilute hydrochloric acid and water for 3-5 times, and drying in a vacuum oven to obtain off-white powder, namely the bisphenol A type poly (arylene ether nitrile) product with the side chain containing amino and terminated by phthalonitrile, wherein the structural formula is shown as the following formula (I-b).

The preparation method of the o-phthalonitrile terminated bisphenol A type poly (arylene ether nitrile) film with the side chain containing amino comprises the following steps: the bisphenol A type polyarylene ether nitrile product (2g) thus prepared was dissolved in N-methylpyrrolidone (15ml) and prepared by a film-forming method by casting. In order to fully remove the solvent, the temperature of the baking oven is set to 80-2 h, 100-2 h, 120-2 h, 160-2 h and 200-2 h.

The preparation method of the bisphenol A type crosslinking poly (arylene ether nitrile) film comprises the following steps: and continuously heating the dried and formed film for heat treatment, treating the film at 280 ℃ for 6h, naturally cooling the film to room temperature, and peeling the sample film from the glass plate to obtain the bisphenol A type cross-linked poly (arylene ether nitrile) film. The film was not dissolved by prolonged standing in a room temperature solution of N-methylpyrrolidone, demonstrating the success of the crosslinking (as shown in bottle 2 in FIG. 2).

The cross-linked poly (arylene ether nitrile) has excellent heat resistance, the glass transition temperature of the cross-linked poly (arylene ether nitrile) can reach 330 ℃, the temperature when 5% of the poly (arylene ether nitrile) is decomposed reaches 505 ℃, the tensile strength reaches 91MPa, the dielectric constant under 1kHz is 3.38, and the dielectric loss is 0.04.

Experimental case 3:

phthalonitrile-terminated bisphenol AF type polyarylene ether nitrile having amino groups in the side chains:

(1) adding potassium carbonate (0.12mol), bisphenol AF (0.0918mol) and 4-aminophenylhydroquinone (0.0102mol) into a reaction bottle containing 50ml of dehydrating agent toluene and 75ml of N-methylpyrrolidone, heating at 130 ℃, reacting and refluxing for 2h, removing water generated by the reaction, and controlling the reaction temperature to be between 130 ℃ and 140 ℃;

(2) adding 2, 6-dichlorobenzonitrile (0.1mol) into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then slowly heating up to 170 ℃ about 2h, maintaining the reaction at 170 ℃ for 2h, and enabling the reaction system to reach the maximum viscosity;

(3) reducing the temperature of the system to 100 ℃, adding 4-nitrophthalonitrile (0.02mol), potassium carbonate (0.02mol) and N-methylpyrrolidone (20ml), and then continuing to react for 4 hours;

(4) and pouring the obtained crude product into acetone, filtering and crushing, respectively washing with acetone, ethanol, dilute hydrochloric acid and water for 3-5 times, and drying in a vacuum oven to obtain white powder, namely the bisphenol AF type poly (arylene ether nitrile) product with the amino-containing phthalonitrile at the side chain, wherein the structural formula is shown as the following formula (I-c).

The preparation method of the phthalonitrile terminated bisphenol AF type poly (arylene ether nitrile) film with the side chain containing amino comprises the following steps: the prepared bisphenol AF type polyarylene ether nitrile product (2g) was dissolved in N-methylpyrrolidone (15ml) and prepared by a film-forming casting method. In order to fully remove the solvent, the temperature of the baking oven is set to 80-2 h, 100-2 h, 120-2 h, 160-2 h and 200-2 h.

The preparation method of the bisphenol AF type cross-linked polyaryl ether nitrile film comprises the following steps: and continuously heating the dried and formed film for heat treatment, treating the film at 280 ℃ for 6h, naturally cooling the film to room temperature, and stripping the sample film from the glass plate to obtain the bisphenol AF type cross-linked poly (arylene ether nitrile) film. The film was not dissolved by prolonged standing in a room temperature solution of N-methylpyrrolidone, demonstrating the success of the crosslinking (as shown in bottle 3 in FIG. 2).

The cross-linked poly (arylene ether nitrile) has excellent heat resistance, the glass transition temperature of the cross-linked poly (arylene ether nitrile) can reach 336 ℃, the temperature for 5 percent decomposition reaches 515 ℃, the tensile strength reaches 95MPa, the dielectric constant under 1kHz is 2.72, and the dielectric loss is 0.05.

Experimental case 4:

phthalonitrile-terminated bisphenol S type polyarylene ether nitrile having an amino group in the side chain:

(1) adding potassium carbonate (0.12mol), bisphenol S (0.0918mol) and 4-aminophenylhydroquinone (0.0102mol) into a reaction bottle containing 50ml of dehydrating agent toluene and 75ml of N-methylpyrrolidone, heating at 130 ℃, reacting and refluxing for 2h, removing water generated by the reaction, and controlling the reaction temperature to be between 130 ℃ and 140 ℃;

(2) adding 2, 6-dichlorobenzonitrile (0.1mol) into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then slowly heating up to 170 ℃ about 2h, maintaining the reaction at 170 ℃ for 2h, and enabling the reaction system to reach the maximum viscosity;

(3) reducing the temperature of the system to 100 ℃, adding 4-nitrophthalonitrile (0.02mol), potassium carbonate (0.02mol) and N-methylpyrrolidone (20ml), and then continuing to react for 4 hours;

(4) and pouring the obtained crude product into acetone, filtering and crushing, respectively washing with acetone, ethanol, dilute hydrochloric acid and water for 3-5 times, and drying in a vacuum oven to obtain white powder, namely the bisphenol S type poly (arylene ether nitrile) product with the side chain containing amino and terminated by phthalonitrile, wherein the structural formula is shown as the following formula (I-d).

The preparation method of the o-phthalonitrile terminated bisphenol S type poly (arylene ether nitrile) film with the side chain containing amino comprises the following steps: the bisphenol S type polyarylene ether nitrile product (2g) thus prepared was dissolved in N-methylpyrrolidone (15ml) and prepared by a film-forming method by casting. In order to fully remove the solvent, the temperature of the baking oven is set to 80-2 h, 100-2 h, 120-2 h, 160-2 h and 200-2 h.

The preparation method of the bisphenol S type cross-linked polyaryl ether nitrile film comprises the following steps: and continuously heating the dried and formed film for heat treatment, treating the film at 280 ℃ for 6h, naturally cooling the film to room temperature, and peeling the sample film from the glass plate to obtain the bisphenol S type cross-linked poly (arylene ether nitrile) film. The film was not dissolved by prolonged standing in a room temperature solution of N-methylpyrrolidone, demonstrating the success of the crosslinking (as shown in bottle 4 in FIG. 2).

The cross-linked poly (arylene ether nitrile) has excellent heat resistance, the glass transition temperature of the cross-linked poly (arylene ether nitrile) can reach 382 ℃, the temperature for 5 percent decomposition reaches 490 ℃, the tensile strength reaches 90MPa, the dielectric constant under 1kHz is 3.80, and the dielectric loss is 0.05.

Experimental case 5:

phthalonitrile-terminated p-phenylene polyarylene ether nitrile having an amino group in the side chain:

(1) adding potassium carbonate (0.12mol), hydroquinone (0.0918mol) and 4-aminophenylhydroquinone (0.0102mol) into a reaction bottle containing 50ml of dehydrating agent toluene and 75ml of N-methylpyrrolidone, heating at 130 ℃, reacting and refluxing for 2h, removing water generated by the reaction, and controlling the reaction temperature to be between 130 ℃ and 140 ℃;

(2) adding 2, 6-dichlorobenzonitrile (0.1mol) into the system, maintaining the reaction at the temperature of 130-140 ℃ for 1h, then slowly heating up to 170 ℃ about 2h, maintaining the reaction at 170 ℃ for 2h, and enabling the reaction system to reach the maximum viscosity;

(3) reducing the temperature of the system to 100 ℃, adding 4-nitrophthalonitrile (0.02mol), potassium carbonate (0.02mol) and N-methylpyrrolidone (30ml), and then continuing to react for 4 hours;

(4) and pouring the obtained crude product into acetone, filtering and crushing, respectively washing with acetone, ethanol, dilute hydrochloric acid and water for 3-5 times, and drying in a vacuum oven to obtain white powder, namely the p-phenylene polyaryl ether nitrile product with the amino-containing phthalonitrile end-capped side chain, wherein the structural formula is shown as the following formula (I-e).

The preparation method of the p-phenylene polyaryl ether nitrile film with the amino-containing phthalonitrile end capping at the side chain comprises the following steps: the prepared p-benzene type polyarylene ether nitrile product (2g) was dissolved in N-methylpyrrolidone (20ml) and prepared by a film-forming method by tape casting. In order to fully remove the solvent, the temperature of the baking oven is set to 80-2 h, 100-2 h, 120-2 h, 160-2 h and 200-2 h.

The preparation method of the p-benzene cross-linking type poly (arylene ether nitrile) film comprises the following steps: and (3) continuously heating the dried and formed film for heat treatment, treating the film at 260 ℃ for 8h, naturally cooling the film to room temperature, and stripping the sample film from the glass plate to obtain the p-benzene cross-linked poly (arylene ether nitrile) film. The film was not dissolved by prolonged standing in a room temperature solution of N-methylpyrrolidone, demonstrating the success of the crosslinking (as shown in bottle 5 in FIG. 2).

The cross-linked poly (arylene ether nitrile) has excellent heat resistance, the glass transition temperature of the cross-linked poly (arylene ether nitrile) can reach 350 ℃, the temperature when 5% of the poly (arylene ether nitrile) is decomposed reaches 516 ℃, the tensile strength reaches 96MPa, the dielectric constant under 1kHz is 3.70, and the dielectric loss is 0.03.