A hypercrosslinked polyamide-imide polymer and a method for preparing the same

Abstract

A hypercrosslinked polyamide-imide polymer and its preparation method are disclosed. The polymer possesses multiple active adsorption sites, including carbonyl groups, imide rings, and amides, providing abundant nitrogen and oxygen heteroatoms and a regular polymer network structure. Because the hypercrosslinked polyamide-imide polymer carries a large number of positive charges and has a regular polymer network structure, it enhances electrostatic interactions with anions, allowing bromine, iodine, and dye anions to be uniformly immobilized on the adsorbent. Simultaneously, its oxygen-containing, nitrogen-containing, and fluorine-containing functional groups can act as Lewis basic sites to combine with bromine, iodine, and organic dyes. The preparation method is simple and reduces costs. The hypercrosslinked polyamide-imide polymer has broad application prospects in the preparation of pollutant adsorption materials.

Description

Technical Field

[0001] This invention relates to an organic polymer and its preparation method, and more particularly to a hypercrosslinked polyamide-imide polymer and its preparation method. Background Technology

[0002] Hypercrosslinked polyamide-imide is a high-performance specialty polymer material widely used in aerospace, electronics, and other fields due to its excellent resistance to high and low temperatures, superior mechanical properties, and outstanding dielectric properties. In the field of environmental science, the application of hypercrosslinked polyamide-imide is mainly focused on wastewater treatment and pollutant separation.

[0003] Due to their excellent solvent resistance and thermal stability, hypercrosslinked polyamide-imides can remain stable in a variety of solvents, making them excellent for treating waste solutions containing organic pollutants. However, traditional hypercrosslinked polyamide-imides only contain amide and imide groups, resulting in fewer active sites and lower heteroatom content, thus limiting the functional groups available for effectively adsorbing and immobilizing pollutants. Furthermore, with the development of chemical technology, environmental requirements for adsorbents are becoming increasingly stringent. Therefore, hypercrosslinked polyamide-imides with multiple active sites and high heteroatom content have attracted widespread attention from the academic community and environmentalists.

[0004] Due to the rapid kinetics of Lewis acid-catalyzed reactions, the network structure of hypercrosslinked polyamide-imide polymers in the prior art is highly irregular, which limits the ability to synthesize hypercrosslinked polyamide-imides with precise pore structures. Summary of the Invention

[0005] The purpose of this invention is to provide a hypercrosslinked polyamide-imide polymer and its preparation method. This polymer has multiple active adsorption sites such as carbonyl groups, imide rings, and amides, and provides abundant nitrogen and oxygen heteroatoms. Moreover, the hypercrosslinked polyamide-imide polymer carries a large number of positive charges, which enhances the electrostatic interaction with anions, thereby fixing bromine, iodine, and dye anions on the adsorbent. At the same time, the oxygen-containing, nitrogen-containing, and fluorine-containing functional groups it carries can act as Lewis basic sites to combine with bromine, iodine, and organic dyes.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] The first objective of this invention is to provide a novel hypercrosslinked polyamide-imide polymer, the hypercrosslinked polyamide-imide polymer having the structural formula shown in formula (I):

[0008]

[0009] Among them, AR is

[0010]

[0011] Any one of them.

[0012] The second objective of this invention is to provide a novel method for preparing a hypercrosslinked polyamide-imide polymer, comprising: placing 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), a diamine monomer, and dry calcium chloride in a reaction flask; adding a mixture of pyridine, triphenyl phosphite, and N-methylpyrrolidone as a solvent to the reaction flask; placing the reaction flask on a magnetic stirrer; heating and stirring; and observing the 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)... After dissolving (1,3-dioxoisoindoline-5-carboxylic acid), N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 100–180 °C for 3–84 h, followed by natural cooling. The resulting yellow precipitate was washed 6–8 times with methanol and anhydrous acetone until the filtrate was colorless. Subsequently, Soxhlet extraction was performed with acetone at 45–85 °C for 12–48 h. The obtained polymer was placed in a vacuum drying oven at 40–80 °C for 12 h. Finally, a novel hypercrosslinked polyamide-imide polymer was prepared. The specific reaction equation is as follows:

[0013]

[0014] To better achieve the above technical solution, the structural formula of the diamine monomer in the preparation method of the novel hypercrosslinked polyamide-imide polymer of the present invention is shown in formula (II):

[0015] H2N-RA-NH2 formula (II), where AR is...

[0016]

[0017] Any one of them.

[0018] To better achieve the above technical solution, in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention, the molar mass ratio of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) to the diamine monomer is 1:(1 ～ 5.8).

[0019] To better achieve the above technical solution, in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention, the volume ratio of pyridine, triphenyl phosphite, and N-methylpyrrolidone is 1:(2). ～ 8.5): (6 ～ 11.5).

[0020] To better achieve the above technical solution, the preparation method of 2,2',2"-((benzene-1,3,5-triyltri(oxo))tris(3-(trifluoromethyl)benzene-4,1-diyl))tris(1,3-dioxoisoindole-5-carboxylic acid) in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention is as follows:

[0021] Step 1, Reduction Reaction: Under a nitrogen atmosphere, tris(4-nitrophenyl)amine and the catalyst were dispersed in ethanol in a three-necked round-bottom flask. The flask was then placed in an oil bath and stirred until homogeneous. The mixture was heated until the reaction temperature reached equilibrium. Hydrazine hydrate was then added dropwise to the reaction system using a constant-pressure funnel, with the dropping rate controlled at 4-5 s intervals between drops, yielding mixture A. This mixture was then reacted under reflux for 1 step. ～ For 3 days, the reduction of the sample was observed by timed TLC. After the reaction was complete, the catalyst in the solution was removed by filtration through a sintered glass funnel. The filtrate was concentrated by rotary evaporation to remove excess hydrazine hydrate, yielding mixture B. Mixture B was added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The pale yellow precipitate was thoroughly washed with distilled water to remove any remaining solvent and reducing agent. After vacuum drying, it was eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine. The specific reaction is as follows:

[0022]

[0023] Step 2, Ring-closing reaction: Under a nitrogen atmosphere, tris(4-aminophenyl)amine and trimellitic anhydride were dispersed in 20–60 mL of glacial acetic acid in a three-necked round-bottom flask. The mixture was mechanically stirred at room temperature for 1–5 h. After the sample in the flask was homogeneous, the reaction was heated for 12–60 h. The product was filtered and washed 3–5 times with methanol, and then dried in a vacuum drying oven at 60 °C for 24 h to obtain 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid). The specific reaction equation is as follows:

[0024]

[0025] To better achieve the above technical solution, in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention, the mass-volume ratio of tris(4-nitrophenyl)amine, catalyst and ethanol in step one is (1.9-18) g: (0.1-2) g: (25-250) mL.

[0026] To better achieve the above technical solution, in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention, the catalyst is palladium on carbon.

[0027] In order to better achieve the above technical solution, in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention, in step one above, the temperature is slowly raised to 75-100℃, the reflux time is 1-2h, hydrazine hydrate is added dropwise, and the reaction is carried out at 75-100℃ for 15-30h. After the reaction is completed, the temperature is lowered to 20-40℃.

[0028] In order to better achieve the above technical solution, in the preparation method of a novel hypercrosslinked polyamide-imide polymer of the present invention, the mass-volume ratio of tris(4-aminophenyl)amine, trimellitic anhydride and glacial acetic acid in step two above is (1-7.5) g: (3-22) g: (20-100) mL.

[0029] A third objective of this invention is to provide an application for preparing a hypercrosslinked poly(amide-imide) polymer, which is used for the adsorption of bromine, iodine, and dyes. The process is as follows: First, prepare cyclohexane solutions of bromine and iodine with concentrations of 0.01–0.1 mol / L and Congo red and methylene blue dyes with concentrations of 10–80 mg / L, respectively. Place 5.0 mg of the hypercrosslinked polyamide-imide polymer in a dry glass bottle, and add 2–50 mL of bromine, iodine, or dye solution to the bottle. At fixed intervals, aspirate the solution from the glass bottle and measure the absorbance using a UV spectrophotometer. Determine the residual amounts of bromine, iodine, and dye in the solution based on the absorbance curve of the solution containing bromine, iodine, and dye. Then, calculate the adsorption capacity of the adsorbent by subtracting the residual amounts of bromine, iodine, and dye from the initial amounts of bromine, iodine, and dye in the solution.

[0030] The advantages and positive effects of this invention are:

[0031] 1. The polymer of this invention possesses multiple active adsorption sites, including carbonyl groups, imide rings, and amides, providing abundant nitrogen and oxygen heteroatoms and a regular polymer network structure. Because the hypercrosslinked polyamide-imide polymer carries a large number of positive charges and has a regular polymer network structure, it enhances the electrostatic interaction with anions, allowing bromine, iodine, and dye anions to be uniformly immobilized on the adsorbent. Simultaneously, its oxygen-containing, nitrogen-containing, and fluorine-containing functional groups can act as Lewis basic sites to combine with bromine, iodine, and organic dyes. Therefore, this novel hypercrosslinked polyamide-imide polymer can be widely used in the preparation of pollutant adsorption materials, showing broad application prospects in the field of pollutant adsorption materials.

[0032] 2. The method for preparing the novel hypercrosslinked polyamide-imide polymer of the present invention uses tri(4-nitrophenyl)amine as a raw material to prepare the triamino monomer tri(4-aminophenyl)amine through a reduction reaction. Then, the triamino monomer is reacted with trimellitic anhydride through a hot ring-closing reaction to prepare the tridentate imide acid monomer 2,2',2”-(nitrile tri(phenyl-4,1-diyl)tri(1,3-dioxoisoindoline-5-carboxylic acid). A series of novel hypercrosslinked polyamide-imide polymers with different functional groups are prepared using this triacid monomer and four diamine monomers. The synthetic route of the present invention is simpler and the cost is reduced. The hypercrosslinked polyamide-imide polymer has multiple active adsorption sites and abundant nitrogen and oxygen heteroatoms. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0034] Figure 1 The infrared spectra of the novel hypercrosslinked polyamide-imide polymers 1-4 of Examples 1, 6, 11, and 16 of this invention are shown.

[0035] Figure 2 XPS spectra of the novel hypercrosslinked polyamide-imide polymers 1-4 of Examples 1, 6, 11, and 16 of this invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0037] A novel hypercrosslinked polyamide-imide polymer, the structure of which is shown in formula (I):

[0038]

[0039] in, In any of the above, the polymer of the present invention is introduced into the main chain to enhance the stacking ability of the molecular chain through hydrogen bonding, thereby generating a mesoporous structure; the introduction of side groups such as trifluoromethyl and methyl disrupts the coplanarity of the electron cloud in the benzene ring and inhibits the generation of conjugated structures. At the same time, trifluoromethyl has a large free volume, thereby increasing the specific surface area and porosity of the polymer; the presence of nitrogen / oxygen heteroatoms, fluorine-containing groups and imide rings in the molecular chain provides ion exchange capacity, promotes intramolecular and intermolecular charge transfer, and enables the novel hypercrosslinked polyamide-imide polymer to form a good interaction with pollutants; the novel hypercrosslinked polyamide-imide polymer is widely used in the preparation of pollutant adsorption materials and has broad application prospects in the field of pollutant adsorption materials.

[0040] The above-mentioned method for preparing the novel hypercrosslinked polyamide-imide polymer comprises: placing 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), a diamine monomer, and dry calcium chloride in a reaction flask; adding a mixture of pyridine, triphenyl phosphite, and N-methylpyrrolidone as a solvent to the reaction flask; placing the reaction flask on a magnetic stirrer; heating and stirring; and observing the dissolution of 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid); then adding N-methylpyrrolidone dropwise to dissolve the remaining diamine monomer; and finally adding the solution at 100 °C. ～ Reaction 3 at 180℃ ～ After 84 hours of natural cooling, the resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, it was heated at 45°C. ～ Soxhlet extraction with acetone at 85℃ for 12 minutes ～ After 48 hours, the resulting polymer was placed in 40... ～ The novel hypercrosslinked polyamide-imide polymer was finally prepared by drying in a vacuum oven at 80℃ for 12 hours. The specific reaction equation is as follows:

[0041]

[0042] Furthermore, in the preparation method of the novel hypercrosslinked polyamide-imide polymer of the present invention, the structural formula of the diamine monomer is shown in formula (II): H2N-RA-NH2, where AR is...

[0043]

[0044] Any of the monomers can be replaced during the preparation of novel hypercrosslinked polyamide-imide polymers. By replacing different monomers, polymers with different structures can be prepared. By changing the type of polymer, different types of novel hypercrosslinked polyamide-imide polymers can be prepared.

[0045] Furthermore, in the preparation method of the novel hypercrosslinked polyamide-imide polymer of the present invention, the molar ratio of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) to the diamine monomer is 1:(1 ～ 5.8), preferably, the molar ratio of 2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) to the diamine monomer is 1:(1 ～ 5.6).

[0046] Furthermore, in the preparation method of the novel hypercrosslinked polyamide-imide polymer of the present invention, the volume ratio of pyridine, triphenyl phosphite, and N-methylpyrrolidone is 1:(2). ～ 8.5): (6 ～ 11.5), preferably, the volume ratio of pyridine, triphenyl phosphite, and N-methylpyrrolidone is 1:(2). ～ 8): (6) ～ 11).

[0047] The preparation method of 2,2',2"-((benzene-1,3,5-triyltri(oxo))tris(3-(trifluoromethyl)benzene-4,1-diyl))tris(1,3-dioxoisoindole-5-carboxylic acid) in a novel hypercrosslinked polyamide-imide polymer is as follows:

[0048] Step 1, Reduction Reaction: Under a nitrogen atmosphere, tris(4-nitrophenyl)amine and the catalyst are dispersed in ethanol in a three-necked round-bottom flask. The flask is then placed in an oil bath and stirred. After the sample is thoroughly mixed, it is heated. When the reaction temperature reaches equilibrium, hydrazine hydrate is added dropwise to the reaction system using a constant-pressure funnel, with the dropping rate controlled at 4-5 s intervals between drops, to obtain mixture A. The mass-to-volume ratio of tris(4-nitrophenyl)amine, catalyst, and ethanol is (1.9–18) g:(0.1–2) g:(25–250) mL. Preferably, the mass-to-volume ratio of tris(4-nitrophenyl)amine, catalyst, and ethanol in this invention is... The reaction mixture consisted of (1.9–16.2) g : (0.1–1.9) g : (25–85) mL, and was reacted under reflux for 1–3 days. The reduction of the sample was observed by timed TLC. After the reaction was complete, the catalyst in the solution was removed by filtration through a sintered glass funnel. The filtrate was concentrated by a rotary evaporator to remove excess hydrazine hydrate, yielding mixture B. Mixture B was added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The pale yellow precipitate was thoroughly washed with distilled water to remove any remaining solvent and reducing agent. After vacuum drying, it was eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine. The specific reaction is as follows:

[0049]

[0050] Step 2, Ring-locking reaction: Under a nitrogen atmosphere, tris(4-aminophenyl)amine and trimellitic anhydride are dispersed in 20–60 mL of glacial acetic acid in a three-necked round-bottom flask. The mixture is mechanically stirred at room temperature for 1–5 h. After the sample in the flask is homogeneously mixed, the reaction is heated for 12–60 h. The preferred mass-to-volume ratio of tris(4-aminophenyl)amine, trimellitic anhydride, and glacial acetic acid is (1–7.5) g:(3–22) g:(20–100) mL. The mass-to-volume ratio of tris(4-aminophenyl)amine, trimellitic anhydride, and glacial acetic acid was (1–7.3) g : (3–21.8) g : (20–85) mL. The product was filtered and washed 3–5 times with methanol, then dried in a vacuum drying oven at 60°C for 24 h to obtain the 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid). The specific reaction equation is as follows:

[0051]

[0052] The novel hypercrosslinked polyamide-imide polymer prepared according to the above method has the following application in the adsorption of bromine, iodine, and dyes: First, cyclohexane solutions of bromine and iodine with concentrations of 0.01–0.1 mol / L and Congo red and methylene blue dyes with concentrations of 10–80 mg / L are prepared, respectively. 5.0 mg of the novel hypercrosslinked polyamide-imide polymer is placed in a dry glass bottle, and 2–50 mL of bromine, iodine, or dye solution is added to the bottle. At fixed intervals, the solution in the glass bottle is aspirated, and the absorbance is measured using a UV spectrophotometer. The residual amounts of bromine, iodine, and dye in the solution are determined based on the absorbance curve of the solution containing bromine, iodine, and dye. Then, the adsorption capacity of the adsorbent is calculated by subtracting the residual amounts of bromine, iodine, and dye from the initial amounts in the solution.

[0053] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0054] Example 1

[0055] I. Synthesis of Tris(4-Aminophenyl)amine

[0056] Tris(4-nitrophenyl)amine (3.8 g, 10 mmol) and palladium / carbon (10%, 0.21 g) were dispersed in ethanol (55 mL). After the sample was thoroughly mixed, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, the palladium / carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. The mixture was then added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The product was collected by filtration, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 2.47 g.

[0057] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0058] Tris(4-aminophenyl)amine (2.4 g, 8.27 mmol) and trimellitic anhydride (15.23 g, 79.26 mmol) were dispersed in 60 mL of glacial acetic acid under a nitrogen atmosphere and mechanically stirred at room temperature for 3 h. After the sample in the flask was thoroughly mixed, the mixture was heated for 24 h. The product was filtered and washed 3-5 times with methanol, and then dried in a vacuum drying oven at 60 °C for 24 h to obtain 12.138 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0059] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0060] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.16 g, 0.5 mmol), o-toluidine (0.169 g, 0.8 mmol), and 0.2 g of dry calcium chloride were placed in a reaction flask, and 0.5 mL of pyridine, 1.5 mL of triphenyl phosphite, and 3.5 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 100°C for 12 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.2214 g of the novel hypercrosslinked polyamide-imide polymer 1 was prepared.

[0061] Example 2

[0062] I. Synthesis of Tris(4-Aminophenyl)amine

[0063] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (11.76 g, 30.9 mmol) and palladium / carbon was replaced with (10%, 0.517 g) and dispersed in ethanol (150 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 8.82 g.

[0064] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0065] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (6.32 g, 21.76 mmol) and trimellitic anhydride was replaced with (19.28 g, 100 mmol) and dispersed in 75 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 17.88 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0066] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0067] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.2 g, 0.65 mmol), o-toluidine (0.255 g, 1.2 mmol), and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.0 mL of pyridine, 4.0 mL of triphenyl phosphite, and 8.0 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 110°C for 14 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.315 g of the novel hypercrosslinked polyamide-imide polymer 1 was prepared.

[0068] Example 3

[0069] I. Synthesis of Tris(4-Aminophenyl)amine

[0070] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (18.79 g, 49 mmol) and palladium / carbon was replaced with (10%, 1 g) and dispersed in ethanol (250 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 14.09 g.

[0071] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0072] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (7.5 g, 25.83 mmol) and trimellitic anhydride was replaced with (22.5 g, 117 mmol) in 90 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 18.03 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0073] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0074] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.256 g, 0.8 mmol), o-toluidine (0.286 g, 1.35 mmol) and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.4 mL of pyridine, 8 mL of triphenyl phosphite and 12 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 120°C for 20 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 16 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.323 g of the novel hypercrosslinked polyamide-imide polymer 1 was prepared.

[0075] Example 4

[0076] I. Synthesis of Tris(4-Aminophenyl)amine

[0077] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (22.36 g, 58.8 mmol) and palladium / carbon was replaced with (10%, 1.2 g) and dispersed in ethanol (290 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 16.77 g.

[0078] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0079] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (8.3 g, 28.5 mmol) and trimellitic anhydride was replaced with (23.7 g, 123 mmol) and dispersed in 80 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 19.2 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0080] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0081] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.304 g, 0.95 mmol), o-toluidine (0.318 g, 1.5 mmol), and 0.8 g of dry calcium chloride were placed in a reaction flask, and 1.8 mL of pyridine, 12 mL of triphenyl phosphite, and 15 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 140℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 18 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.372 g of the novel hypercrosslinked polyamide-imide polymer 1 was prepared.

[0082] Example 5

[0083] I. Synthesis of Tris(4-Aminophenyl)amine

[0084] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (24.32 g, 64 mmol) and palladium / carbon was replaced with (10%, 2 g) and dispersed in ethanol (320 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 18.19 g.

[0085] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0086] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (10.15 g, 35 mmol) and trimellitic anhydride was replaced with (26.88 g, 140 mmol) and dispersed in 100 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated and reacted for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), 23.6 g.

[0087] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0088] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.352 g, 1.1 mmol), o-toluidine (0.3604 g, 1.7 mmol), and 1.2 g of dry calcium chloride were placed in a reaction flask, and 2 mL of pyridine, 15 mL of triphenyl phosphite, and 18 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 160℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 24 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.413 g of the novel hypercrosslinked polyamide-imide polymer 1 was prepared.

[0089] Example 6

[0090] I. Synthesis of Tris(4-Aminophenyl)amine

[0091] Tris(4-nitrophenyl)amine (3.8 g, 10 mmol) and palladium / carbon (10%, 0.21 g) were dispersed in ethanol (55 mL). After the sample was thoroughly mixed, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, the palladium / carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. The mixture was then added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The product was collected by filtration, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 2.47 g.

[0092] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0093] Tris(4-aminophenyl)amine (2.4 g, 8.27 mmol) and trimellitic anhydride (15.23 g, 79.26 mmol) were dispersed in 60 mL of glacial acetic acid under a nitrogen atmosphere and mechanically stirred at room temperature for 3 h. After the sample in the flask was thoroughly mixed, the mixture was heated for 24 h. The product was filtered and washed 3-5 times with methanol, and then dried in a vacuum drying oven at 60 °C for 24 h to obtain 12.138 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0094] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 2

[0095] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.16 g, 0.5 mmol), p-phenylenediamine (0.086 g, 0.8 mmol), and 0.2 g of dry calcium chloride were placed in a reaction flask, and 0.5 mL of pyridine, 1.5 mL of triphenyl phosphite, and 3.5 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 100°C for 12 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.147 g of the novel hypercrosslinked polyamide-imide polymer 2 was prepared.

[0096] Example 7

[0097] I. Synthesis of Tris(4-Aminophenyl)amine

[0098] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (11.76 g, 30.9 mmol) and palladium / carbon was replaced with (10%, 0.517 g) and dispersed in ethanol (150 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 8.82 g.

[0099] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0100] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (6.32 g, 21.76 mmol) and trimellitic anhydride was replaced with (19.28 g, 100 mmol) and dispersed in 75 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 17.88 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0101] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 2

[0102] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.2 g, 0.65 mmol), p-phenylenediamine (0.13 g, 1.2 mmol), and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.0 mL of pyridine, 4.0 mL of triphenyl phosphite, and 8.0 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 110°C for 14 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.188 g of the novel hypercrosslinked polyamide-imide polymer 2 was prepared.

[0103] Example 8

[0104] I. Synthesis of Tris(4-Aminophenyl)amine

[0105] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (18.79 g, 49 mmol) and palladium / carbon was replaced with (10%, 1 g) and dispersed in ethanol (250 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 14.09 g.

[0106] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0107] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (7.5 g, 25.83 mmol) and trimellitic anhydride was replaced with (22.5 g, 117 mmol) in 90 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 18.03 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0108] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 2

[0109] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.256 g, 0.8 mmol), p-phenylenediamine (0.1458 g, 1.35 mmol) and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.4 mL of pyridine, 8 mL of triphenyl phosphite and 12 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 120°C for 20 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 16 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.236 g of the novel hypercrosslinked polyamide-imide polymer 2 was prepared.

[0110] Example 9

[0111] I. Synthesis of Tris(4-Aminophenyl)amine

[0112] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (22.36 g, 58.8 mmol) and palladium / carbon was replaced with (10%, 1.2 g) and dispersed in ethanol (290 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 16.77 g.

[0113] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0114] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (8.3 g, 28.5 mmol) and trimellitic anhydride was replaced with (23.7 g, 123 mmol) and dispersed in 80 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 19.2 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0115] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 2

[0116] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.304 g, 0.95 mmol), p-phenylenediamine (0.162 g, 1.5 mmol), and 0.8 g of dry calcium chloride were placed in a reaction flask, and 1.8 mL of pyridine, 12 mL of triphenyl phosphite, and 15 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 140℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 18 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.278 g of the novel hypercrosslinked polyamide-imide polymer 2 was prepared.

[0117] Example 10

[0118] I. Synthesis of Tris(4-Aminophenyl)amine

[0119] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (24.32 g, 64 mmol) and palladium / carbon was replaced with (10%, 2 g), both dispersed in ethanol (320 mL). After the sample was mixed thoroughly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed using a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture, yielding a pale yellow precipitate. The product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 18.19 g.

[0120] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0121] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (10.15 g, 35 mmol) and trimellitic anhydride was replaced with (26.88 g, 140 mmol) and dispersed in 100 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated and reacted for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), 23.6 g.

[0122] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 2

[0123] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.352 g, 1.1 mmol), p-phenylenediamine (0.1836 g, 1.7 mmol) and 1.2 g of dry calcium chloride were placed in a reaction flask, and 2 mL of pyridine, 15 mL of triphenyl phosphite and 18 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 160℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 24 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.332 g of the novel hypercrosslinked polyamide-imide polymer 2 was prepared.

[0124] Example 11

[0125] I. Synthesis of Tris(4-Aminophenyl)amine

[0126] Tris(4-nitrophenyl)amine (3.8 g, 10 mmol) and palladium / carbon (10%, 0.21 g) were dispersed in ethanol (55 mL). After the sample was thoroughly mixed, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, the palladium / carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. The mixture was then added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The product was collected by filtration, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 2.47 g.

[0127] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0128] Tris(4-aminophenyl)amine (2.4 g, 8.27 mmol) and trimellitic anhydride (15.23 g, 79.26 mmol) were dispersed in 60 mL of glacial acetic acid under a nitrogen atmosphere and mechanically stirred at room temperature for 3 h. After the sample in the flask was thoroughly mixed, the mixture was heated for 24 h. The product was filtered and washed 3-5 times with methanol, and then dried in a vacuum drying oven at 60 °C for 24 h to obtain 12.138 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0129] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 3

[0130] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.16 g, 0.5 mmol), m-phenylenediamine (0.086 g, 0.8 mmol), and 0.2 g of dry calcium chloride were placed in a reaction flask, and 0.5 mL of pyridine, 1.5 mL of triphenyl phosphite, and 3.5 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 100°C for 12 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.244 g of the novel hypercrosslinked polyamide-imide polymer 3 was prepared.

[0131] Example 12

[0132] I. Synthesis of Tris(4-Aminophenyl)amine

[0133] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (11.76 g, 30.9 mmol) and palladium / carbon was replaced with (10%, 0.517 g) and dispersed in ethanol (150 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 8.82 g.

[0134] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0135] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (6.32 g, 21.76 mmol) and trimellitic anhydride was replaced with (19.28 g, 100 mmol) and dispersed in 75 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 17.88 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0136] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 3

[0137] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.2 g, 0.65 mmol), m-phenylenediamine (0.13 g, 1.2 mmol), and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.0 mL of pyridine, 4.0 mL of triphenyl phosphite, and 8.0 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 110°C for 14 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.341 g of the novel hypercrosslinked polyamide-imide polymer 3 was prepared.

[0138] Example 13

[0139] I. Synthesis of Tris(4-Aminophenyl)amine

[0140] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (18.79 g, 49 mmol) and palladium / carbon was replaced with (10%, 1 g) and dispersed in ethanol (250 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 14.09 g.

[0141] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0142] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (7.5 g, 25.83 mmol) and trimellitic anhydride was replaced with (22.5 g, 117 mmol) in 90 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 18.03 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0143] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 3

[0144] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.256 g, 0.8 mmol), m-phenylenediamine (0.1458 g, 1.35 mmol) and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.4 mL of pyridine, 8 mL of triphenyl phosphite and 12 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 120°C for 20 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 16 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.247 g of a novel hypercrosslinked polyamide-imide polymer was prepared.

[0145] Example 14

[0146] I. Synthesis of Tris(4-Aminophenyl)amine

[0147] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (22.36 g, 58.8 mmol) and palladium / carbon was replaced with (10%, 1.2 g) and dispersed in ethanol (290 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 16.77 g.

[0148] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0149] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (8.3 g, 28.5 mmol) and trimellitic anhydride was replaced with (23.7 g, 123 mmol) and dispersed in 80 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 19.2 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0150] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 3

[0151] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.304 g, 0.95 mmol), m-phenylenediamine (0.162 g, 1.5 mmol) and 0.8 g of dry calcium chloride were placed in a reaction flask, and 1.8 mL of pyridine, 12 mL of triphenyl phosphite and 15 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 140°C for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 18 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.293 g of the novel hypercrosslinked polyamide-imide polymer 3 was prepared.

[0152] Example 15

[0153] I. Synthesis of Tris(4-Aminophenyl)amine

[0154] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (24.32 g, 64 mmol) and palladium / carbon was replaced with (10%, 2 g) and dispersed in ethanol (320 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 18.19 g.

[0155] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0156] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (10.15 g, 35 mmol) and trimellitic anhydride was replaced with (26.88 g, 140 mmol) and dispersed in 100 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated and reacted for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), 23.6 g.

[0157] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 3

[0158] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.352 g, 1.1 mmol), m-phenylenediamine (0.1836 g, 1.7 mmol) and 1.2 g of dry calcium chloride were placed in a reaction flask, and 2 mL of pyridine, 15 mL of triphenyl phosphite and 18 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 160℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 24 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.347 g of the novel hypercrosslinked polyamide-imide polymer 3 was prepared.

[0159] Example 16

[0160] I. Synthesis of Tris(4-Aminophenyl)amine

[0161] Tris(4-nitrophenyl)amine (3.8 g, 10 mmol) and palladium / carbon (10%, 0.21 g) were dispersed in ethanol (55 mL). After the sample was thoroughly mixed, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, the palladium / carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. The mixture was then added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The product was collected by filtration, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 2.47 g.

[0162] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0163] Tris(4-aminophenyl)amine (2.4 g, 8.27 mmol) and trimellitic anhydride (15.23 g, 79.26 mmol) were dispersed in 60 mL of glacial acetic acid under a nitrogen atmosphere and mechanically stirred at room temperature for 3 h. After the sample in the flask was thoroughly mixed, the mixture was heated for 24 h. The product was filtered and washed 3-5 times with methanol, and then dried in a vacuum drying oven at 60 °C for 24 h to obtain 12.138 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0164] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 4

[0165] 0.16 g (0.5 mmol) of 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), 0.256 g (0.8 mmol) of 2,2-bis(trifluoromethyl)diaminobiphenyl (0.256 g, 0.8 mmol) and 0.2 g of dry calcium chloride were placed in a reaction flask, and 0.5 mL of pyridine, 1.5 mL of triphenyl phosphite and 3.5 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 100°C for 12 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.271 g of the novel hypercrosslinked polyamide-imide polymer 4 was prepared.

[0166] Example 17

[0167] I. Synthesis of Tris(4-Aminophenyl)amine

[0168] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (11.76 g, 30.9 mmol) and palladium / carbon was replaced with (10%, 0.517 g) and dispersed in ethanol (150 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 8.82 g.

[0169] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0170] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (6.32 g, 21.76 mmol) and trimellitic anhydride was replaced with (19.28 g, 100 mmol) and dispersed in 75 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 17.88 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0171] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 4

[0172] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.2 g, 0.65 mmol), 2,2-bis(trifluoromethyl)diaminobiphenyl (0.384 g, 1.2 mmol), and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.0 mL of pyridine, 4.0 mL of triphenyl phosphite, and 8.0 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 110°C for 14 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 12 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.335 g of the novel hypercrosslinked polyamide-imide polymer 4 was prepared.

[0173] Example 18

[0174] I. Synthesis of Tris(4-Aminophenyl)amine

[0175] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (18.79 g, 49 mmol) and palladium / carbon was replaced with (10%, 1 g) and dispersed in ethanol (250 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for one day, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 14.09 g.

[0176] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0177] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (7.5 g, 25.83 mmol) and trimellitic anhydride was replaced with (22.5 g, 117 mmol) in 90 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 32 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 18.03 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0178] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0179] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.256 g, 0.8 mmol), 2,2-bis(trifluoromethyl)diaminobiphenyl (0.432 g, 1.35 mmol), and 0.4 g of dry calcium chloride were placed in a reaction flask, and 1.4 mL of pyridine, 8 mL of triphenyl phosphite, and 12 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 120°C for 20 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65°C for 16 h. The obtained polymer was placed in a vacuum drying oven at 50°C for 12 h. Finally, 0.688 g of the novel hypercrosslinked polyamide-imide polymer 4 was prepared.

[0180] Example 19

[0181] I. Synthesis of Tris(4-Aminophenyl)amine

[0182] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (22.36 g, 58.8 mmol) and palladium / carbon was replaced with (10%, 1.2 g) and dispersed in ethanol (290 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 16.77 g.

[0183] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0184] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (8.3 g, 28.5 mmol) and trimellitic anhydride was replaced with (23.7 g, 123 mmol) and dispersed in 80 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 19.2 g of 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

[0185] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 4

[0186] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.304 g, 0.95 mmol), 2,2-bis(trifluoromethyl)diaminobiphenyl (0.48 g, 1.5 mmol), and 0.8 g of dry calcium chloride were placed in a reaction flask, and 1.8 mL of pyridine, 12 mL of triphenyl phosphite, and 15 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 140℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 18 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.509 g of the novel hypercrosslinked polyamide-imide polymer 4 was prepared.

[0187] Example 20

[0188] I. Synthesis of Tris(4-Aminophenyl)amine

[0189] The method was the same as in Example 1, except that tris(4-nitrophenyl)amine was replaced with (24.32 g, 64 mmol) and palladium / carbon was replaced with (10%, 2 g) and dispersed in ethanol (320 mL). After the sample was mixed evenly, it was heated to 75 °C. When the reaction temperature reached equilibrium, hydrazine hydrate was slowly added dropwise under nitrogen protection. The mixture was then refluxed for 2 days, and the reduction was observed by timed TLC. After reflux, palladium on carbon was removed through a sintered glass funnel, and the filtrate was concentrated using a rotary evaporator to remove excess hydrazine hydrate. Under stirring, the mixture was added to an ice-water mixture to obtain a pale yellow precipitate. The formed product was filtered and collected, thoroughly washed with distilled water, vacuum dried, and eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine, 18.19 g.

[0190] II. Synthesis of 2,2',2”-(Cryonitrile(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid)

[0191] The method was the same as in Example 1. Tris(4-aminophenyl)amine was replaced with (10.15 g, 35 mmol) and trimellitic anhydride was replaced with (26.88 g, 140 mmol) and dispersed in 100 mL of glacial acetic acid under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 3 h. After the sample in the flask was mixed evenly, the mixture was heated and reacted for 54 h. The product was filtered and washed with methanol 3-5 times. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), 23.6 g.

[0192] III. Preparation of Novel Hypercrosslinked Polyamide-Imide Polymer 1

[0193] 2,2',2”-(cyanotris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) (0.352 g, 1.1 mmol), 2,2-bis(trifluoromethyl)diaminobiphenyl (0.544 g, 1.7 mmol), and 1.2 g of dry calcium chloride were placed in a reaction flask, and 2 mL of pyridine, 15 mL of triphenyl phosphite, and 18 mL of... A mixture of N-methylpyrrolidone was used as a solvent and added to the reaction flask. The reaction flask was placed on a magnetic stirrer and heated and stirred. After 2,2',2”-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) was observed to dissolve, N-methylpyrrolidone was added dropwise to dissolve the residual diamine monomer. The reaction was carried out at 160℃ for 24 h and then naturally cooled. The resulting yellow precipitate was washed 6-8 times with methanol and anhydrous acetone until the filtrate was colorless. Then, Soxhlet extraction was performed with acetone at 65℃ for 24 h. The obtained polymer was placed in a vacuum drying oven at 50℃ for 12 h. Finally, 0.582 g of the novel hypercrosslinked polyamide-imide polymer 4 was prepared.

[0194] from Figure 1 The infrared spectra show that the infrared characteristic absorption peaks of the four hypercrosslinked polyamide-imide polymers are extremely similar. The stretching vibration of C=O was observed at 1689, 1705, and 1712 cm⁻¹, the stretching vibration peak of the benzene ring carbon skeleton in polyamide-imide was observed at 1589, 1511, and 1380 cm⁻¹, and the stretching vibration peak of CN was observed at 1332 cm⁻¹. The structures of these four polymers are basically similar, but polymer 4 has its own unique CF stretching vibration peak at 1249 cm⁻¹, which confirms that polymer 4 contains trifluoromethyl groups. The results prove the successful synthesis of target polymers 1-4.

[0195] from Figure 2The XPS spectra of the four hypercrosslinked polyamide-imide polymers show C1s spectra, revealing three types of carbon: CC sp2 carbon (284.41 eV), CN (285.66 eV), and C=O (287.83 eV), respectively. Polymer 4 also exhibits a unique CF (292.05 eV) binding energy. The N1s spectrum shows only one binding energy, a CN binding energy peak (399.98 eV), formed by the nitrogen from both the triphenylamine (CN) and amide (CN) units. A high-resolution O1s spectrum was observed at 530.9 eV, belonging to the oxygen in the C=O unit of the amide unit. In the unique F1s spectrum of polymer 4, two peaks belong to trifluoromethyl (-CF3), corresponding to a half-ionic CF bond (687.9 eV) and a covalent CF bond (689.7 eV). These results indicate that the elements and functional groups of the polymer are exactly as expected, which is consistent with the FT-IR spectrum of the polymer. This further proves that the polymer has multiple active adsorption sites such as carbonyl, imide ring and amide, and provides N / O heteroatoms.

[0196] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for preparing a hypercrosslinked polyamide-imide polymer, characterized in that, The method involves placing 2,2',2''-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), a diamine monomer, and dry calcium chloride in a reaction flask. A mixture of pyridine, triphenyl phosphite, and N-methylpyrrolidone is added to the reaction flask as a solvent. The flask is placed on a magnetic stirrer and heated and stirred. After observing the dissolution of 2,2',2''-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid), N-methylpyrrolidone is added dropwise to dissolve the remaining diamine monomer. The reaction is carried out at 100-180°C for 3-84 hours, followed by natural cooling. The resulting yellow precipitate is washed 6-8 times with methanol and anhydrous acetone until the filtrate is colorless. The precipitate is then reacted at 45-85°C. The polymer was extracted with acetone using a Soxhlet extractor for 12-48 hours. The resulting polymer was then placed in a vacuum drying oven at 40-80°C for 12 hours to prepare a novel hypercrosslinked polyamide-imide polymer. The structural formula of the diamine monomer is shown in formula (II): Equation (II), where AR is: , , , Any one of them; The molar ratio of 2,2',2''-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) to the diamine monomer is 1:(1~5.8). The structural formula of the 2,2',2''-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) is: .

2. The method for preparing a hypercrosslinked polyamide-imide polymer according to claim 1, characterized in that, The volume ratio of pyridine, triphenyl phosphite and N-methylpyrrolidone is 1:(2~8.5):(6~11.5).

3. The method for preparing a hypercrosslinked polyamide-imide polymer according to claim 1, characterized in that, The preparation method of the 2,2',2''-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid) is as follows: Step 1, Reduction Reaction: Under a nitrogen atmosphere, tris(4-nitrophenyl)amine and the catalyst were dispersed in ethanol in a three-necked round-bottom flask. After being placed in an oil bath and stirred, the mixture was heated until the reaction temperature reached equilibrium. Then, hydrazine hydrate was added dropwise to the reaction system using a constant-pressure funnel at a drop interval of 4-5 seconds to obtain mixture A. The mixture was then reacted under reflux for 1-3 days. The reduction of the sample was observed by TLC at regular intervals. After the reaction was completed, the catalyst in the solution was removed by filtration through a sintered glass funnel. The filtrate was concentrated by a rotary evaporator to remove excess hydrazine hydrate to obtain mixture B. Mixture B was added to an ice-water mixture under stirring to obtain a pale yellow precipitate. The pale yellow precipitate was thoroughly washed with distilled water to remove any remaining solvent and reducing agent. After vacuum drying, the precipitate was eluted by dichloromethane column chromatography to obtain a white solid powder, namely tris(4-aminophenyl)amine. Step 2, Ring-closing reaction: Tris(4-aminophenyl)amine and trimellitic anhydride were dispersed in 20-60 mL of glacial acetic acid in a three-necked round-bottom flask under a nitrogen atmosphere. The mixture was mechanically stirred at room temperature for 1-5 h. After the sample in the flask was evenly mixed, the mixture was heated for 12-60 h. The product was filtered and washed 3-5 times with methanol. Then it was dried in a vacuum drying oven at 60 °C for 24 h to obtain the 2,2',2''-(nitrile tris(phenyl-4,1-diyl)tris(1,3-dioxoisoindoline-5-carboxylic acid).

4. The method for preparing a hypercrosslinked polyamide-imide polymer according to claim 3, characterized in that, In step one, the mass-to-volume ratio of tris(4-nitrophenyl)amine, catalyst, and ethanol is (1.9~18)g:(0.1~2)g:(25~250)mL.

5. The method for preparing a hypercrosslinked polyamide-imide polymer according to claim 3, characterized in that, The catalyst is palladium on carbon.

6. The method for preparing a hypercrosslinked polyamide-imide polymer according to claim 3, characterized in that, In step one, the temperature is slowly raised to 75-100℃, refluxed for 1-2 hours, and then hydrazine hydrate is added dropwise. The reaction is carried out at 75-100℃ for 15-30 hours. After the reaction is completed, the temperature is lowered to 20-40℃. In step two, the mass-to-volume ratio of tris(4-aminophenyl)amine, trimellitic anhydride and glacial acetic acid is (1-7.5) g: (3-22) g: (20-100) mL.

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