Polyimide film having aggregation-induced emission effect and method for preparing the same

Abstract

This invention discloses a polyimide film with aggregation-induced emission (AIE) and its preparation method, belonging to the field of flexible electronic light emission. Through side-linking technology, this invention achieves, for the first time, molecular-level bonding between TPE fluorophores and PI polymers, endowing the PI film material with excellent photoluminescence properties while possessing outstanding mechanical strength and thermal stability. Furthermore, this invention can be extended to other polymer systems, potentially solving the scientific problem currently faced by flexible display light-emitting materials where luminescence, thermal, and mechanical properties cannot be simultaneously achieved. Therefore, the technical solution proposed in this invention can provide diverse design ideas and raw material bases for the molecular structure design and efficient preparation of PI and its film materials containing TPE motifs, contributing to the advancement and deepening of PI material applications in flexible electronics.

Description

Technical Field

[0001] This invention belongs to the field of flexible electron luminescence, specifically relating to a polyimide film with aggregation-induced emission effect and its preparation method. Background Technology

[0002] 2019 was considered the inaugural year for flexible displays, with Samsung and Huawei successively launching the Galaxy Fold and Mate X foldable phones, respectively, revolutionizing consumers' perceptions of traditional mobile phones. Flexible displays instantly became a market hotspot and a core driver of future development. Flexible displays significantly expand display space formats and are a key technological requirement for emerging display fields such as wearable devices and smartphones. In recent years, new flexible display materials have attracted increasing attention and have experienced rapid development. Due to the flexibility and ease of processing of polymers, and their ability to be easily formed into thin films through spin coating or inkjet printing, the exploration of polymer luminescent materials in the flexible display field is growing rapidly. Conjugated polymers such as poly(p-styrene) [Burroughes, JH; et al. Nature. 1990, 347.], poly(p-phenylene) [Grem, G.; et al. Synthetic Metals. 1992, 51.], and polythiophene [Perepichka, IF.; et al. Advanced Materials. 2005, 17.] have become important light-emitting materials for large-area display devices, commonly referred to as polymer light-emitting diodes (PLEDs), and have shown great potential in advanced flexible displays. However, the solubility, thermal stability, processability, and photochemical stability of these conjugated light-emitting polymers are key issues restricting their application and development, and these issues urgently need to be addressed.

[0003] Polyimide (PI) possesses excellent thermo-oxidative stability, unique electrical properties, good radiation and solvent resistance, and high mechanical strength, attracting considerable attention in various fields such as aerospace, automotive, and optoelectronics. Aromatic PI was first reported by Marston Bogert in 1908, and after more than a century of development, its synthesis methods and molding processes are relatively mature. Based on the functionality of the dianhydrides and diamines used, researchers have constructed a series of functional PI grades for different applications. However, few studies have applied PI to the field of light emission, such as polymer light-emitting diodes (LEDs). Traditional PI exhibits little or no photoluminescence (PL) and low fluorescence quantum yield (Φ) due to intermolecular or intramolecular charge transfer (CT) interactions. PL This makes it difficult for PI, such an excellent polymer material, to be used as a photofunctional material. Summary of the Invention

[0004] The technical problem to be solved:

[0005] To overcome the shortcomings of existing technologies, this invention provides a polyimide film with aggregation-induced emission (AIE) and its preparation method. Through side-linking technology, it achieves, for the first time, molecular-level bonding between TPE fluorophores and PI polymers, endowing the PI film material with excellent photoluminescence properties, while also possessing outstanding mechanical strength and thermal stability. Furthermore, this invention can be extended to other polymer systems, potentially solving the scientific problem currently faced by flexible display luminescent materials where luminescence, thermal, and mechanical properties cannot be simultaneously achieved. Therefore, the technical solution proposed in this invention can provide diverse design ideas and raw material bases for the molecular structure design and efficient preparation of PI and its film materials containing TPE motifs, contributing to the advancement and deepening of PI material applications in the field of flexible electronics.

[0006] The technical solution of the present invention is: a polyimide film with aggregation-induced emission effect, wherein the molecular structure of the polyimide film is represented by the following general formula:

[0007]

[0008] Wherein, L is the diacid anhydride residue moiety, and its molar fraction is 50%;

[0009] M is the diamine residue moiety, with a molar fraction of 25% to 40%;

[0010] V is a diamine residue moiety with a hydroxyl group, and its molar fraction is 10% to 25%;

[0011] TPE is a tetraphenylvinyl group, which is grafted onto the side chain of the polymer molecule via ester groups. Its molar fraction is 1 to 2 times that of the V part of the diamine with hydroxyl groups, i.e., p is 1-2.

[0012] A further technical solution of the present invention is that the diamine M is any one or a combination of the following compounds, and its chemical structural formula is as follows:

[0013]

[0014] A further technical solution of the present invention is that the diacid anhydride L is any one or a combination of the following compounds, and its chemical structural formula is as follows:

[0015]

[0016] A further technical solution of the present invention is that the diamine V containing a hydroxyl group is any one or a combination of the following compounds, and its chemical structural formula is as follows:

[0017]

[0018] A method for preparing a polyimide film with aggregation-induced emission effect, comprising the following specific steps:

[0019] Step 1: Add carboxylic acid compound B with TPE motif and solvent K to the reactor, stir to dissolve, cool to -10 to 5°C, add compound W, and continue stirring for 10 to 24 hours; concentrate the reaction system, remove solvent K and excess compound W to obtain compound D;

[0020] The molar ratio of compound W to carboxylic acid compound B containing the TPE moiety is 1.0 to 3.0:1;

[0021] The carboxylic acid compound B with the TPE moiety has a mass fraction of 2 wt% to 8 wt% in the above reaction system;

[0022] Step 2: Dissolve the polyimide polymer T containing hydroxyl groups in solvent K to obtain solution C;

[0023] Step 3: Add compound D, acid-binding agent Q, and solvent K to the reactor, stir to dissolve, cool to -10 to 5°C, add solution C, and continue the reaction at -10 to 5°C for 2 to 6 hours;

[0024] The mass ratio of compound D to polymer T is 3 to 6:1;

[0025] Step 4: Heat the reaction system from Step 3 to reflux. After refluxing for 12–24 h, cool the reaction solution to 20–35 °C. Pour the reaction solution into alcohol solvent S for precipitation to obtain fibrous polymer. Wash the fibrous polymer 2–3 times with alcohol solvent S, and then wash the fibrous polymer 2–3 times with distilled water to obtain polymer Z. Perform Soxhlet extraction on polymer Z with alcohol solvent S for 8–24 h, and finally vacuum dry at 80–160 °C to obtain polymer E containing TPE units.

[0026] Step 5: Dissolve polymer E containing TPE moieties in solvent K. After dissolution, cast the solution into a petri dish and let it stand at 40-80°C for 10-20 hours to evaporate the solvent. Then raise the temperature to 100-180°C and vacuum dry for 2-6 hours. After the temperature drops to 20-35°C, remove the film to obtain a polyimide film with aggregation-induced light emission effect.

[0027] The polymer E containing TPE motifs has a solid content of 4 wt% to 15 wt% in solvent K.

[0028] A further technical solution of the present invention is: the preparation method of the carboxylic acid compound B with the TPE motif is as follows:

[0029] Step 1: Add bromotriphenylene, 4-(ethoxycarbonyl)phenylboronic acid, basic compound G, catalyst F, toluene, alcohol solvent S and distilled water sequentially into the reactor, and reflux at 80-130°C for 6-18 hours;

[0030] The molar ratio of bromotriphenylene to 4-(ethoxycarbonyl)phenylboronic acid is 1:1 to 3.0;

[0031] The molar ratio of the bromotriphenylene to the basic compound G is 1:8 to 16;

[0032] The molar ratio of bromotriphenylene to catalyst F is 1:0.1 to 0.01;

[0033] The volume ratio of distilled water, toluene, and alcohol solvent S is 1:3~6:0.5~2.0;

[0034] The sum of the mass fractions of bromotriphenylene and 4-(ethoxycarbonyl)phenylboronic acid in this reaction system is 3wt% to 10wt%.

[0035] Step 2: After cooling the reaction system of Step 1 to 20-35°C, pour it into an aqueous solution of alkaline compound G for precipitation, and extract it with dichloromethane 2-3 times. After concentrating the organic phase, crude product C is obtained.

[0036] The mass fraction of the alkaline compound G in the aqueous solution is 5 wt% to 30 wt%.

[0037] Step 3: Recrystallize the crude product C 2-3 times using a mixed solvent of alcohol solvent S and water to obtain compound A;

[0038] The volume ratio of the alcohol solvent S to water is 4 to 1:1;

[0039] Step 4: Add compound A, basic compound H, tetrahydrofuran and distilled water to the reactor in sequence, and reflux at 60-120°C for 20-30 hours;

[0040] The molar ratio of the basic compound H to compound A is 2 to 6:1;

[0041] The volume ratio of tetrahydrofuran to distilled water is 0.5–2.0:1;

[0042] The mass fraction of compound A in the above reaction system is 2 wt% to 10 wt%.

[0043] Step 5: Cool the reaction solution obtained in Step 4 to 20-35℃, adjust the pH of the reaction system to 1-4 with acid solution; concentrate to remove tetrahydrofuran, precipitate a white solid, filter, collect the filter cake, wash the filter cake 2-3 times with distilled water, and dry it under vacuum at 60-120℃ for 6-15h to obtain crude product J.

[0044] Step 6: Recrystallize the crude product J 2-3 times using a mixed solvent of alcohol solvent S and water to obtain carboxylic acid compound B containing the TPE unit;

[0045] The volume ratio of the alcohol solvent S to water is 4 to 1:1.

[0046] A further technical solution of the present invention is that the compound W is any one or a combination of oxalyl chloride, thionyl chloride, phosphorus trichloride, phosphorus-free chloride, thionyl chloride, cyanoyl chloride, chloroacetyl chloride, and acetyl chloride.

[0047] A further technical solution of the present invention is that the solvent K is any one or a combination of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, m-cresol, acetonitrile, and dimethyl sulfoxide.

[0048] A further technical solution of the present invention is: the preparation method of the polyimide polymer T with hydroxyl groups is as follows:

[0049] Step 1: Add diamine M, diamine V with hydroxyl group, diacid anhydride L, and catalyst P sequentially into the reactor, and add solvent U to dissolve the solid. React at 60-100℃ for 2-8 hours.

[0050] The molar ratio of the dicarboxylic acid anhydride L, the diamine M, and the diamine V with a hydroxyl group is 1:0 to 1:1 to 0.

[0051] The molar ratio of catalyst P to dicarboxylic acid anhydride L is 1.0 to 3:1;

[0052] The total mass fraction of the diamine M, the diamine V with a hydroxyl group, and the diacid anhydride L in the above reaction system is 10 wt% to 25 wt%.

[0053] Step 2: Add catalyst R, heat the reaction system to 180-200℃ and continue the reaction for 12-24 hours; cool the reaction system to 20-35℃, slowly precipitate the reaction solution in alcohol solvent S to obtain fibrous polymer; wash the polymer 2-3 times with alcohol solvent S, and vacuum dry at 80-140℃ for 8-24 hours to obtain polyimide polymer T with hydroxyl groups.

[0054] A further technical solution of the present invention is that the solvent U is any one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, m-cresol, and γ-butyrolactone.

[0055] Beneficial effects

[0056] The beneficial effects of this invention are as follows: This invention provides a method for preparing polyimide thin film materials with aggregation-induced emission effect (AIE). It aims to utilize the advantages of tetraphenylethylene (TPE), such as its ease of synthesis, convenient functionalization, and the ability to retain a considerable AIE effect even after modification with different functional groups. By incorporating TPE moieties into the polyimide side chains, the molecular-level problem of polyimide Φ is solved. PL The scientific problem of excessively low or even no light emission.

[0057] The technical solution proposed in this invention is completed in three steps, with each step producing a product with a precise molecular structure. There is no raw material waste, and the yield is high, with an overall yield exceeding 90%. The monomers that can be used in the synthesis of PI have diverse molecular structures, which results in a similar diversity in the molecular structure of the final PI polymer containing hydroxyl groups. Therefore, PI exhibiting the AIE effect offers greater flexibility and tunability in molecular structure design, leading to greater molecular structure diversity, wider applications, and a synthesis process more suitable for mass production. Furthermore, by controlling the content of hydroxyl groups on the PI molecular chain, this invention allows for controllable adjustment of the TPE unit grafting amount, thereby achieving control over the luminescent properties and Φ of the final PI material. PL Fine-grained regulation.

[0058] This invention solves the problem of PI's non-luminescence by introducing the TPE moiety into the PI molecular framework. A TPE functional molecule (TPE-COOH) with a carboxyl functional group in its molecular structure was designed and synthesized. Through esterification grafting, the TPE moiety was incorporated into the PI side chain for the first time, resulting in a series of PI film materials with AIE effect. PL The maximum value can reach 17.6%. By adjusting the flexibility of the dianhydride or the grafting amount of TPE phosphors, the Φ of the PI film can be adjusted. PL Flexible adjustment.

[0059] Furthermore, the PI film prepared by this invention also possesses high mechanical strength (tensile strength > 85.0 MPa, tensile modulus 2–3 GPa), good flexibility (elongation at break > 10.0%), and outstanding heat resistance (T0.0). g >230℃, T d5％ (>400℃), which helps to promote the widespread application of PI thin film materials in the field of flexible displays. Attached Figure Description

[0060] Figure 1 A schematic diagram of the synthetic route for TPE-COOH functional molecules;

[0061] Figure 2 This is a schematic diagram of the synthetic route for polyimides with hydroxyl groups on the side chain;

[0062] Figure 3 A schematic diagram of the synthetic route for photoluminescent polyimide with TPE motifs in the side chain;

[0063] Figure 4 The images show the polyimide with TPE moiety in the side chain prepared in Example 8: (a) its appearance under natural light, and (b) its luminescence after being irradiated by a 365nm ultraviolet lamp in a dark room.

[0064] Figure 5 Thermal performance curves of photoluminescent polyimide films with TPE motifs in the side chains prepared in Examples 1, 4, 5, 7, and 8: (a) TGA curve, (b) curve of internal friction factor as a function of temperature;

[0065] Figure 6 Tensile stress-strain curves of photoluminescent polyimide films with TPE motifs in the side chains prepared in Examples 1, 4, 5, 7, and 8;

[0066] Figure 7 The fluorescence excitation and fluorescence emission spectra of photoluminescent polyimide films with TPE motifs in the side chains prepared in Examples 2, 3, 4, 6, and 8 are shown.

[0067] Figure 8 The luminescence of the photoluminescent polyimide with TPE-based side chains prepared in Example 8 in different solutions: (a) pure DMF solution, (b) a mixed solution of DMF and water (V DMF / V H2O =1:9), (c) A mixed solution of DMF and water (V DMF / V H2O =1:19), the concentration of the polymer in all three solutions was c = 20 mg / L. Detailed Implementation

[0068] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0069] Currently, tetraphenylethylene (TPE) is one of the most studied small molecules in the AIE (Aggregation-Induced Emission) class. It is a highly efficient fluorophore with aggregation-induced emission properties, emitting blue fluorescence in the aggregated state, and its powder fluorescence quantum yield can reach over 49%. As a pure hydrocarbon AIE functional molecule, TPE has a simple structure and is easy to functionalize, making it an excellent functional molecule for imparting AIE effects to polymers.

[0070] Tetraphenylene has many properties:

[0071] (1) TPE is easy to synthesize, and the four benzene rings of TPE are easy to modify;

[0072] (2) TPE still has a considerable AIE effect after being modified by various functional groups;

[0073] (3) Except for some extreme conditions, such as strong ultraviolet radiation or high temperature exceeding 500°C, TPE basic components have excellent stability under most conditions.

[0074] To address the aforementioned problems, this invention bonds functional molecules with AIE (Alternating Induction Emission) effects to PI (Pi) at the molecular level, constructing a series of PI materials with excellent luminescent properties. This aims to solve the scientific problems of poor thermal stability and insufficient photochemical stability currently faced by luminescent polymers, focusing on overcoming the poor luminescent performance of PI materials. Since TPE molecules possess excellent AIE effects and are easily functionalized, this invention, based on existing technologies, synthesizes a functional molecule containing a carboxyl functional group (TPE-COOH, structural formula as shown below). Figure 1 As shown), a PI polymer with hydroxyl groups in its molecular side chains was prepared (polymer chain structure as shown). Figure 2 (As shown), then the carboxyl group is chlorinated, and the TPE functional molecule is grafted onto the side chain of the PI molecule for the first time by utilizing the esterification reaction of the acyl chloride and the hydroxyl group (synthetic process as shown). Figure 3 As shown in the figure, the TPE fluorescent group and PI are combined at the molecular level, giving PI excellent photoluminescence effect.

[0075] The molecular structure of a polyimide film exhibiting aggregation-induced emission effect according to the present invention has the following general formula:

[0076]

[0077] Wherein, L is the diacid anhydride residue moiety, and its molar fraction is 50%;

[0078] M is the diamine residue moiety, with a molar fraction of 25% to 40%;

[0079] V is a diamine residue moiety with a hydroxyl group, and its molar fraction is 10% to 25%;

[0080] TPE is a tetraphenylvinyl group, which is grafted onto the side chain of the polymer molecule via ester groups. Its molar fraction is 1 to 2 times that of the V part of the diamine with hydroxyl groups, i.e., p is 1-2.

[0081] The diamine M is any one or a combination of the following compounds, and its chemical structural formula is:

[0082]

[0083] The dicarboxylic acid anhydride L is any one or a combination of the following compounds, and its chemical structural formula is:

[0084]

[0085] The diamine V containing a hydroxyl group is any one or a combination of the following compounds, with the following chemical structural formula:

[0086]

[0087] The present invention discloses a method for preparing a polyimide film with aggregation-induced emission effect, the specific steps of which are as follows:

[0088] Step 1: Carboxylic acid compound B with the TPE motif is prepared using the following steps:

[0089] Step 1.1: Add bromotriphenylene, 4-(ethoxycarbonyl)phenylboronic acid, basic compound G, catalyst F, toluene, alcohol solvent S and distilled water sequentially to a single-necked round-bottom flask equipped with a magnetic inlet, and reflux at 80-130°C for 6-18 hours;

[0090] The molar ratio of bromotriphenylene to 4-(ethoxycarbonyl)phenylboronic acid is 1:1 to 3.0;

[0091] The molar ratio of the bromotriphenylene to the basic compound G is 1:8 to 16;

[0092] The molar ratio of bromotriphenylene to catalyst F is 1:0.1 to 0.01;

[0093] The volume ratio of distilled water, toluene, and alcohol solvent S is 1:3~6:0.5~2.0;

[0094] The sum of the mass fractions of bromotriphenylene and 4-(ethoxycarbonyl)phenylboronic acid in the reaction system is 3 wt% to 10 wt%.

[0095] Step 1.2: Cool the reaction system to 20-35°C, pour the reaction solution into an aqueous solution of alkaline compound G for precipitation, and extract with dichloromethane 2-3 times. After concentrating the organic phase, crude product C is obtained.

[0096] The mass fraction of the alkaline compound G in the aqueous solution is 5 wt% to 30 wt%.

[0097] Step 1.3: Recrystallize the crude product C 2-3 times using a mixed solvent of alcohol solvent S and water to obtain compound A;

[0098] The volume ratio of the alcohol solvent S to water is 4 to 1:1;

[0099] Step 1.4: Add compound A, basic compound H, tetrahydrofuran and distilled water sequentially to a three-necked flask equipped with a condenser, and reflux at 60-120°C for 20-30 hours;

[0100] The molar ratio of the basic compound H to compound A is 2 to 6:1;

[0101] The volume ratio of tetrahydrofuran to distilled water is 0.5–2.0:1;

[0102] The mass fraction of compound A in the above reaction system is 2 wt% to 10 wt%.

[0103] Step 1.5: After the reaction is complete, cool the system to 20-35℃, adjust the pH of the reaction system to 1-4 with acid solution; concentrate to remove tetrahydrofuran, precipitate a white solid, filter, collect the filter cake, wash the filter cake 2-3 times with distilled water, and dry it under vacuum at 60-120℃ for 6-15h to obtain crude product J;

[0104] Step 1.6: Recrystallize the crude product J 2-3 times using a mixed solvent of alcohol solvent S and water to obtain carboxylic acid compound B containing the TPE unit;

[0105] The volume ratio of the alcohol solvent S to water is 4 to 1:1;

[0106] Step 2: The polyimide with hydroxyl groups is prepared using the following steps:

[0107] Step 2.1: Add diamine M, diamine V with hydroxyl group, diacid anhydride L, and catalyst P sequentially to a three-necked flask equipped with a mechanical stirrer, and add solvent U to dissolve the solid. React at 60-100℃ for 2-8 hours.

[0108] The molar ratio of the dicarboxylic acid anhydride L, the diamine M, and the diamine V with a hydroxyl group is 1:0 to 1:1 to 0.

[0109] The molar ratio of catalyst P to dicarboxylic acid anhydride L is 1.0 to 3:1;

[0110] The total mass fraction of the diamine M, the diamine V with a hydroxyl group, and the diacid anhydride L in the above reaction system is 10 wt% to 25 wt%.

[0111] Step 2.2: Add catalyst R, heat the reaction system to 180-200℃ and continue the reaction for 12-24 hours; cool the reaction system to 20-35℃, and slowly precipitate the reaction solution in alcohol solvent S to obtain fibrous polymer; wash the polymer 2-3 times with alcohol solvent S and vacuum dry at 80-140℃ for 8-24 hours to obtain polyimide polymer T with hydroxyl groups;

[0112] Step 3: The polyimide film with aggregation-induced emission effect is prepared using the following steps:

[0113] Step 3.1: Add compound B and solvent K to a single-necked flask equipped with a magnetic stir bar and stir to dissolve; cool the reaction system to -10 to 5°C, add compound W, and continue stirring for 10 to 24 hours; concentrate the reaction system to remove solvent K and excess compound W to obtain compound D;

[0114] The molar ratio of compound W to compound B is 1.0 to 3.0:1;

[0115] The mass fraction of compound B in the above reaction system is 2 wt% to 8 wt%.

[0116] Step 3.2: Add compound D, acid-binding agent Q, and solvent K to a three-necked flask equipped with a magnetic inlet, stir to dissolve, and cool the reaction system; dissolve polymer T with solvent K to obtain solution C; when the system is cooled to -10 to 5°C, add solution C and continue the reaction at -10 to 5°C for 2 to 6 hours;

[0117] The mass ratio of compound D to polymer T is 3 to 6:1;

[0118] Step 3.3: Heat the system to reflux and continue the reaction for 12-24 hours. Cool the reaction solution to 20-35°C and pour the reaction solution into alcohol solvent S for precipitation to obtain fibrous polymer. Wash the polymer 2-3 times with alcohol solvent S, and then wash the polymer 2-3 times with distilled water to obtain polymer Z. Perform Soxhlet extraction on polymer Z with alcohol solvent S for 8-24 hours, and finally vacuum dry at 80-160°C to obtain polymer E containing TPE units.

[0119] Step 3.4: Dissolve polymer E in solvent K, then cast it into a petri dish and let it stand at 40-80℃ for 10-20h to evaporate the solvent. Then raise the temperature to 100-180℃ and vacuum dry for 2-6h. After the temperature drops to 20-35℃, remove the film to obtain a polyimide film with aggregation-induced light emission effect.

[0120] The polymer E has a solid content of 4 wt% to 15 wt% in solvent K.

[0121] The alkaline compound G is any one or a combination of sodium carbonate, potassium carbonate, cesium carbonate, rubidium carbonate, potassium acetate, and sodium acetate; the catalyst F is any one or a combination of tetrakis(triphenylphosphine)palladium, di(tri-tert-butylphosphine)palladium, palladium acetate, palladium neopentanoate, and palladium trifluoroacetate; the alkaline compound H is any one or a combination of sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, strontium hydroxide, barium hydroxide, diammonium silver hydroxide, calcium hydroxide, tetrabutylammonium bromide, trioctylmethylammonium chloride, trimethylbenzylammonium chloride, hexadecyltrimethylammonium bromide, triethylbenzylammonium chloride, and 2-hydroxy-N,N,N-trimethylethylamine; the catalyst P is any one or a combination of glacial acetic acid, benzoic acid, phenylacetic acid, and methylbenzoic acid; the catalyst R is isoquinoline, quinoline, pyridine, methylpyridine, and... The solvent S is any one or a combination of methylquinoline; the alcohol solvent S is any one or a combination of ethanol, methanol, and isopropanol; the solvent K is any one or a combination of tetrahydrofuran, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, m-cresol, acetonitrile, and dimethyl sulfoxide; the acyl chloride compound W is any one or a combination of oxaloyl chloride, dichlorosulfoxide, phosphorus trichloride, phosphorus-free chloride, thionyl chloride, cyanoyl chloride, chloroacetyl chloride, and acetyl chloride; the acid-binding agent Q is any one or a combination of pyridine, triethylamine, sodium carbonate, cesium carbonate, potassium carbonate, sodium acetate, N,N-diisopropylethylamine, quinoline, and isoquinoline; the solvent U is any one or a combination of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, m-cresol, and γ-butyrolactone.

[0122] The above technical solution will be further explained below with reference to the embodiments:

[0123] Example 1:

[0124] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (1.3410 g, 4.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 5.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (0.2888 g, 0.25 mmol), 100.0 mL toluene, 22.0 mL ethanol, and 20.0 mL distilled water. The mixture was refluxed at 130°C for 10 h. The reaction mixture was cooled to 30°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of ethanol and water. Ethyl 4-(1,2,2-tristyrene)benzoate was obtained by repeating the reaction three times. Ethyl 4-(1,2,2-tristyrene)benzoate (1.6168 g, 4.00 mmol), sodium hydroxide (480 mg, 12.00 mmol), 15 mL tetrahydrofuran, and 18 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 90 °C for 24 h. The system was cooled to 25 °C, and the pH of the reaction system was adjusted to 2 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed twice with distilled water and dried under vacuum at 120 °C for 6 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (1.5058 g, 4.00 mmol, 40 mL tetrahydrofuran) was added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 5°C, and oxalyl chloride (0.9519 g, 7.50 mmol) was added. The reaction was continued with stirring for 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 3°C ​​for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine DDS (0.3228 g, 1.30 mmol), hydroxyl-containing diamine APAF (0.2563 g, 0.70 mmol), diacid anhydride BTDA (0.6444 g, 2.00 mmol), benzoic acid (0.7328 g, 6.00 mmol), and 20 mL of m-cresol sequentially, and react at 60 °C for 8 h; then add 3 drops of isoquinoline, raise the temperature to 180 °C, and continue the reaction. After 24 hours, the reaction system was cooled to 25°C, and the reaction solution was slowly precipitated in methanol to obtain a fibrous polymer. The polymer was washed three times with methanol and dried under vacuum at 120°C for 12 hours to obtain polyimide T with hydroxyl groups. TPE-COCl (1.5796 g, 4.00 mmol), triethylamine (0.8095 g, 8.00 mmol), and 40 mL of tetrahydrofuran were added to a three-necked flask equipped with a magnetic stir bar, stirred to dissolve, and the reaction system was cooled. 90 mL of... THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to 5°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at 5°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 24 hours, and finally dried under vacuum at 100°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMF, then cast into a petri dish and allowed to stand at 60°C for 20 hours to evaporate the solvent. The temperature was then raised to 160°C and dried under vacuum for 4 hours. After the temperature dropped to 25°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0125] Example 2:

[0126] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (1.3410 g, 4.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 5.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (0.2888 g, 0.25 mmol), 100.0 mL toluene, 20.0 mL ethanol, and 20.0 mL distilled water. The mixture was refluxed at 110°C for 12 h. The reaction mixture was cooled to 25°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of methanol and water. Ethyl 4-(1,2,2-tristyrene)benzoate was obtained by repeating the reaction three times. Ethyl 4-(1,2,2-tristyrene)benzoate (1.6168 g, 4.00 mmol), sodium hydroxide (480 mg, 12.00 mmol), 25 mL tetrahydrofuran, and 25 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 90 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 2 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed three times with distilled water and dried under vacuum at 120 °C for 12 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (1.5058 g, 4.00 mmol) and 40 mL tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 0 °C, and oxalyl chloride (1.1423 g, 9.00 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine ODA (0.6007 g, 3.00 mmol), hydroxyl-containing diamine APAF (0.3662 g, 1.00 mmol), diacid anhydride 6FDA (1.7770 g, 4.00 mmol), benzoic acid (0.9770 g, 8.00 mmol), and 27 mL of m-cresol sequentially. React at 80 °C for 4 h. Add 4 drops of isoquinoline, and raise the temperature to 200 °C to continue the reaction. 20 h; Cool the reaction system to 25 °C, and slowly precipitate the reaction solution in ethanol to obtain a fibrous polymer; Wash the polymer three times with ethanol and dry it under vacuum at 120 °C for 12 h to obtain polyimide T with hydroxyl groups; Add TPE-COCl (1.5796 g, 4.00 mmol), triethylamine (1.0119 g, 10.00 mmol), and 45 mL of tetrahydrofuran to a three-necked flask equipped with a magnetic stir bar, stir to dissolve, and cool the reaction system; Use 100 mL Polyimide T was dissolved in THF to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to -5°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at -5°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 16 hours, and finally dried under vacuum at 130°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMF, then cast into a petri dish and allowed to stand at 60°C for 20 hours to evaporate the solvent. The temperature was then raised to 160°C and dried under vacuum for 6 hours. After the temperature dropped to 30°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0127] Example 3:

[0128] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (2.0115 g, 6.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 8.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (1.2933 g, 0.25 mmol), 150.0 mL toluene, 35.0 mL ethanol, and 35.0 mL distilled water. The mixture was refluxed at 100°C for 12 h. The reaction mixture was cooled to 25°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of methanol and water. Ethyl 4-(1,2,2-tristyrene)benzoate was obtained by repeating the reaction three times. Ethyl 4-(1,2,2-tristyrene)benzoate (2.4252 g, 6.00 mmol), sodium hydroxide (800 mg, 20.00 mmol), 40 mL tetrahydrofuran, and 40 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 90 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 3 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed three times with distilled water and dried under vacuum at 120 °C for 12 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound with the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (2.2587 g, 6.00 mmol) and 80 mL of tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 0 °C, and oxalyl chloride (1.9038 g, 15.00 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine ODA (0.6007 g, 2.60 mmol), hydroxyl-containing diamine APAF (0.3662 g, 1.40 mmol), diacid anhydride 6FDA (1.7770 g, 4.00 mmol), benzoic acid (0.9770 g, 8.00 mmol), and 30 mL of m-cresol sequentially. React at 80 °C for 4 h. Add 4 drops of isoquinoline, and raise the temperature to 200 °C to continue the reaction. 20 h; Cool the reaction system to 25 °C, and slowly precipitate the reaction solution in ethanol to obtain a fibrous polymer; Wash the polymer three times with ethanol and dry it under vacuum at 120 °C for 12 h to obtain polyimide T with hydroxyl groups; Add TPE-COCl (2.3694 g, 6.00 mmol), triethylamine (1.5179 g, 15.00 mmol), and 75 mL of tetrahydrofuran to a three-necked flask equipped with a magnetic stir bar, stir to dissolve, and cool the reaction system; Use 100 mL THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to -5°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at -5°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 14 hours, and finally dried under vacuum at 130°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMAC, then cast into a petri dish and allowed to stand at 70°C for 24 hours to evaporate the solvent. The temperature was then raised to 160°C and dried under vacuum for 4 hours. After the temperature dropped to 30°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0129] Example 4:

[0130] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (1.3410 g, 4.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 5.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (0.2888 g, 0.25 mmol), 100.0 mL toluene, 20.0 mL ethanol, and 20.0 mL distilled water. The mixture was refluxed at 110°C for 12 h. The reaction mixture was cooled to 25°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of methanol and water. The reaction was repeated three times to obtain ethyl 4-(1,2,2-tristyrene)benzoate. ethyl 4-(1,2,2-tristyrene)benzoate (1.6168 g, 4.00 mmol), sodium hydroxide (480 mg, 12.00 mmol), 20 mL tetrahydrofuran, and 20 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 90 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 3 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed twice with distilled water and dried under vacuum at 120 °C for 12 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (1.5058 g, 4.00 mmol) and 40 mL tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 5 °C, and oxalyl chloride (1.0154 g, 8.00 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine ODA (0.6007 g, 3.00 mmol), hydroxyl-containing diamine APAF (0.3662 g, 1.00 mmol), diacid anhydride BPADA (2.0820 g, 4.00 mmol), benzoic acid (0.9770 g, 8.00 mmol), and 27 mL of m-cresol sequentially. React at 80 °C for 4 h. Then add 4 drops of isoquinoline and heat the reaction system to 200 °C to continue the reaction. After 20 hours, the reaction system was cooled to 25°C, and the reaction solution was slowly precipitated in ethanol to obtain a fibrous polymer. The polymer was washed three times with ethanol and dried under vacuum at 120°C for 12 hours to obtain polyimide T with hydroxyl groups. TPE-COCl (1.5796 g, 4.00 mmol), triethylamine (0.8095 g, 8.00 mmol), and 40 mL of tetrahydrofuran were added to a three-necked flask equipped with a magnetic stir bar, stirred to dissolve, and the reaction system was cooled. 110 mL of ethanol was then added to the flask. THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to -5°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at -5°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 12 hours, and finally dried under vacuum at 120°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMF, then cast into a petri dish and allowed to stand at 60°C for 20 hours to evaporate the solvent. The temperature was then raised to 160°C and dried under vacuum for 5 hours. After the temperature dropped to 25°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0131] Example 5:

[0132] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (1.5086 g, 4.50 mmol), 4-(ethoxycarbonyl)phenylboronic acid (1.1174 g, 5.40 mmol), Na₂CO₃ (5.2995 g, 50.00 mol), tetrakis(triphenylphosphine)palladium (0.2889 g, 0.25 mmol), 100.0 mL toluene, 25.0 mL ethanol, and 25.0 mL distilled water. The mixture was refluxed at 100°C for 18 h. The reaction mixture was cooled to 30°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of methanol and water. Ethyl 4-(1,2,2-tristyrene)benzoate was obtained by repeating the reaction three times. Ethyl 4-(1,2,2-tristyrene)benzoate (1.8189 g, 4.50 mmol), sodium hydroxide (600 mg, 15.00 mmol), 30 mL tetrahydrofuran, and 30 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 100 °C for 30 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 2 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed three times with distilled water and dried under vacuum at 120 °C for 12 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound with the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (1.6940 g, 4.50 mmol) and 45 mL of tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 5 °C, and oxalyl chloride (1.2693 g, 10.00 mmol) was added. The reaction was stirred for another 18 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine ODA (0.6007 g, 3.00 mmol), hydroxyl-containing diamine BAP (0.2583 g, 1.00 mmol), diacid anhydride BPDA (1.1769 g, 4.00 mmol), benzoic acid (1.0991 g, 9.00 mmol), and 27 mL of m-cresol sequentially. React at 80 °C for 4 h. Add 4 drops of isoquinoline, raise the temperature to 180 °C, and continue the reaction for 2 hours. 4 h; Cool the reaction system to 25 °C, and slowly precipitate the reaction solution in methanol to obtain a fibrous polymer; Wash the polymer three times with methanol and dry it under vacuum at 120 °C for 16 h to obtain polyimide T with hydroxyl groups; Add TPE-COCl (1.7771 g, 4.50 mmol), triethylamine (1.0119 g, 10.00 mmol), and 60 mL of tetrahydrofuran to a three-necked flask equipped with a magnetic stir bar, stir to dissolve, and cool the reaction system; Use 150 mL THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to -5°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at -5°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 12 hours, and finally dried under vacuum at 120°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMSO, then cast into a petri dish and allowed to stand at 80°C for 20 hours to evaporate the solvent. The temperature was then raised to 160°C and dried under vacuum for 5 hours. After the temperature dropped to 25°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0133] Example 6:

[0134] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (2.0115 g, 6.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 8.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (1.2933 g, 0.25 mmol), 150.0 mL toluene, 35.0 mL ethanol, and 35.0 mL distilled water. The mixture was refluxed at 120°C for 12 h. The reaction mixture was cooled to 30°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of methanol and water. Ethyl 4-(1,2,2-tristyrene)benzoate was obtained by repeating the reaction three times. Ethyl 4-(1,2,2-tristyrene)benzoate (2.4252 g, 6.00 mmol), sodium hydroxide (800 mg, 20.00 mmol), 40 mL tetrahydrofuran, and 40 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 100 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 2 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed three times with distilled water and dried under vacuum at 120 °C for 16 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated three times to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound with the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (2.2587 g, 6.00 mmol) and 80 mL of tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 0 °C, and oxalyl chloride (1.9038 g, 15.00 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine ODA (0.6007 g, 2.60 mmol), hydroxyl-containing diamine APAF (0.3662 g, 1.40 mmol), diacid anhydride BPADA (2.0820 g, 4.00 mmol), benzoic acid (0.9770 g, 8.00 mmol), and 30 mL of m-cresol sequentially. React at 80 °C for 4 h. Then add 4 drops of isoquinoline and raise the temperature to 200 °C to continue the reaction. 20 h; Cool the reaction system to 25 °C, and slowly precipitate the reaction solution in ethanol to obtain a fibrous polymer; Wash the polymer three times with ethanol and dry it under vacuum at 100 °C for 16 h to obtain polyimide T with hydroxyl groups; Add TPE-COCl (2.3694 g, 6.00 mmol), triethylamine (1.5179 g, 15.00 mmol), and 80 mL of tetrahydrofuran to a three-necked flask equipped with a magnetic stir bar, stir to dissolve, and cool the reaction system; Use 120 mL THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to 0°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at 0°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 14 hours, and finally dried under vacuum at 120°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMAC, then cast into a petri dish and allowed to stand at 70°C for 24 hours to evaporate the solvent. The temperature was then raised to 180°C and dried under vacuum for 4 hours. After the temperature dropped to 30°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0135] Example 7:

[0136] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (1.3410 g, 4.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 5.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (0.2888 g, 0.25 mmol), 80.0 mL toluene, 20.0 mL ethanol, and 20.0 mL distilled water. The mixture was refluxed at 110°C for 12 h. The reaction mixture was cooled to 25°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of ethanol and water. Ethyl 4-(1,2,2-tristyrene)benzoate was obtained by repeating the reaction three times. Ethyl 4-(1,2,2-tristyrene)benzoate (1.6168 g, 4.00 mmol), potassium hydroxide (672 mg, 12.00 mmol), 20 mL tetrahydrofuran, and 20 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 90 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 3 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed twice with distilled water and dried under vacuum at 120 °C for 12 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (1.5058 g, 4.00 mmol) and 40 mL tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 5 °C, and oxalyl chloride (1.2693 g, 10.00 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine BAPP (1.2316 g, 3.00 mmol), hydroxyl-containing diamine BAP (0.2583 g, 1.00 mmol), diacid anhydride BPDA (1.1769 g, 4.00 mmol), benzoic acid (1.0991 g, 9.00 mmol), and 27 mL of m-cresol sequentially. React at 80 °C for 4 h. Add 4 drops of isoquinoline, and raise the temperature to 180 °C to continue the reaction. 24h; Cool the reaction system to 25℃, and slowly precipitate the reaction solution in ethanol to obtain a fibrous polymer; Wash the polymer three times with ethanol and dry it under vacuum at 140℃ for 10h to obtain polyimide T with hydroxyl groups; Add TPE-COCl (1.5796g, 4.00mmol), triethylamine (0.8095g, 8.00mmol), and 45mL tetrahydrofuran to a three-necked flask equipped with a magnetic stir bar, stir to dissolve, and cool the reaction system; Use 150mL THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to 0°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at 0°C for 4 hours. The system was heated to reflux and the reaction was continued for 14 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 12 hours, and finally dried under vacuum at 120°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMF, then cast into a petri dish and allowed to stand at 70°C for 20 hours to evaporate the solvent. The temperature was then raised to 180°C and dried under vacuum for 5 hours. After the temperature dropped to 25°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0137] Example 8:

[0138] A single-necked round-bottom flask equipped with a magnetic inlet was successively added with bromotriphenylene (1.3410 g, 4.00 mmol), 4-(ethoxycarbonyl)phenylboronic acid (0.9700 g, 5.00 mmol), Na₂CO₃ (4.7696 g, 45.00 mol), tetrakis(triphenylphosphine)palladium (0.2888 g, 0.25 mmol), 100.0 mL toluene, 20.0 mL ethanol, and 20.0 mL distilled water. The mixture was refluxed at 110°C for 12 h. The reaction mixture was cooled to 25°C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized from a mixed solvent of ethanol and water. The reaction was repeated three times to obtain ethyl 4-(1,2,2-tristyrene)benzoate. ethyl 4-(1,2,2-tristyrene)benzoate (1.6168 g, 4.00 mmol), sodium hydroxide (480 mg, 12.00 mmol), 20 mL tetrahydrofuran, and 20 mL distilled water were added sequentially to a three-necked flask equipped with a condenser, and the mixture was refluxed at 90 °C for 24 h. The system was cooled to 25 °C, and the pH of the reaction system was adjusted to 3 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed twice with distilled water and dried under vacuum at 120 °C for 12 h to obtain crude product J. Crude product J was recrystallized from a mixed solvent of methanol and water. The reaction was repeated twice to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound with the TPE motif. 4-(1,2,2-tristyrene)benzoic acid (1.5058 g, 4.00 mmol) and 40 mL tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred until dissolved. The reaction system was cooled to 5 °C, and oxalyl chloride (0.9519 g, 7.50 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxalyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use.To a three-necked flask equipped with a mechanical stirrer, add diamine ODA (0.2002 g, 1.00 mmol), hydroxyl-containing diamine APAF (0.3662 g, 1.00 mmol), diacid anhydride BPADA (0.8885 g, 2.00 mmol), benzoic acid (0.4885 g, 4.00 mmol), and 11 mL of m-cresol sequentially. React at 85 °C for 4 h. Then add 3 drops of isoquinoline and raise the temperature to 190 °C to continue the reaction. After 18 hours, the reaction system was cooled to 30°C, and the reaction solution was slowly precipitated in ethanol to obtain a fibrous polymer. The polymer was washed three times with ethanol and dried under vacuum at 120°C for 12 hours to obtain polyimide T with hydroxyl groups. TPE-COCl (1.5796 g, 4.00 mmol), triethylamine (0.8095 g, 8.00 mmol), and 40 mL of tetrahydrofuran were added to a three-necked flask equipped with a magnetic stir bar, stirred to dissolve, and the reaction system was cooled. 80 mL of ethanol was then added to the flask. THF was used to dissolve polyimide T to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to 0°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at 0°C for 4 hours. The system was heated to reflux and the reaction was continued for 16 hours. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 16 hours, and finally dried under vacuum at 100°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMAC, then cast into a petri dish and allowed to stand at 70°C for 16 hours to evaporate the solvent. The temperature was then raised to 140°C and dried under vacuum for 5 hours. After the temperature dropped to 25°C, the film was removed to obtain a polyimide film with photoluminescent properties.

[0139] Table 1. Thermal performance data of photoluminescent polyimide films with TPE motifs in the side chains prepared in Examples 1, 4, 5, 7, and 8.

[0140]

[0141] Table 2. Mechanical properties of photoluminescent polyimide films with TPE-containing side chains prepared in Examples 1, 4, 5, 7, and 8.

[0142]

[0143] Table 3. Maximum excitation wavelength, maximum emission wavelength, and fluorescence quantum yield data of photoluminescent polyimide films with TPE-containing side chains prepared in Examples 2, 3, 4, 6, and 8.

[0144]

[0145] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for preparing a polyimide film with aggregation-induced emission effect, characterized in that: 1.3410 g and 4.00 mmol of bromotriphenylene, 0.9700 g and 5.00 mmol of 4-(ethoxycarbonyl)phenylboronic acid, 4.7696 g and 45.00 mol of Na₂CO₃, 0.2888 g and 0.25 mmol of tetrakis(triphenylphosphine)palladium, 100.0 mL of toluene, 20.0 mL of ethanol, and 20.0 mL of distilled water were added sequentially to a single-necked round-bottom flask equipped with a magnetic inlet. The mixture was refluxed at 110 °C for 12 h. The reaction mixture was cooled to 25 °C, and the reaction solution was poured into an aqueous solution of sodium bicarbonate for precipitation. The precipitate was extracted three times with dichloromethane, and the organic phase was concentrated to obtain the crude product. The crude product C was recrystallized three times with a mixed solvent of methanol and water to obtain ethyl 4-(1,2,2-triphenylene)benzoate. 1.6168 g and 4.00 mmol of ethyl 4-(1,2,2-tristyrene)benzoate, 480 mg and 12.00 mmol of sodium hydroxide, 20 mL of tetrahydrofuran, and 20 mL of distilled water were added sequentially to a three-necked flask equipped with a condenser. The mixture was refluxed at 90 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 3 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, and a white solid precipitated. The solid was filtered, the filter cake was collected, washed twice with distilled water, and dried under vacuum at 120 °C for 12 h to obtain crude product J. The crude product J was recrystallized twice using a mixed solvent of methanol and water to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 1.5058 g of 4.00 mmol of 4-(1,2,2-tristyrene)benzoic acid and 40 mL of tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred to dissolve. The reaction system was cooled to 5°C, and 1.0154 g of 8.00 mmol of oxaloyl chloride was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxaloyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2°C for later use. To a three-necked flask equipped with a mechanical stirrer, 0.6007 g and 3.00 mmol of diamine ODA, 0.3662 g and 1.00 mmol of hydroxyl-containing diamine APAF, 2.0820 g and 4.00 mmol of diacid anhydride BPADA, 0.9770 g and 8.00 mmol of benzoic acid, and 27 mL of m-cresol were added sequentially, and the mixture was reacted at 80 °C for 4 h. Four drops of isoquinoline were added, and the reaction mixture was heated to 200 °C and reacted for another 20 h. The reaction mixture was cooled to 25 °C, and the reaction solution was slowly precipitated in ethanol to obtain a fibrous polymer. The polymer was washed three times with ethanol and dried under vacuum at 120 °C for 12 h to obtain hydroxyl-containing polyimide T. Add 1.5796 g and 4.00 mmol of TPE-COCl, 0.8095 g and 8.00 mmol of triethylamine and 40 mL of tetrahydrofuran to a three-necked flask equipped with a magnetic induction magnet, stir to dissolve, and cool the reaction system. Polyimide T was dissolved in 110 mL of THF to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to -5 °C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at -5 °C for 4 h. The system was then heated to reflux and the reaction was continued for 16 h. The reaction solution was cooled to 25 °C, and the solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 12 h, and finally dried under vacuum at 120 °C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMF, then cast into a petri dish and allowed to stand at 60 °C for 20 h to evaporate the solvent. The temperature was then raised to 160 °C and dried under vacuum for 5 h. After the temperature dropped to 25 °C, the film was removed to obtain a polyimide film with photoluminescent properties.

2. A method for preparing a polyimide film with aggregation-induced emission effect, characterized in that: To a single-necked round-bottom flask equipped with a magnetic inlet, add 2.0115 g of 6.00 mmol bromotriphenylene, 0.9700 g of 8.00 mmol 4-(ethoxycarbonyl)phenylboronic acid, 4.7696 g of 45.00 mol Na₂CO₃, 1.2933 g of 0.25 mmol tetra(triphenylphosphine)palladium, 150.0 mL toluene, 35.0 mL ethanol, and 35.0 mL distilled water sequentially. Reflux the mixture at 120 °C for 12 h. Cool the reaction mixture to 30 °C, precipitate the mixture in an aqueous solution of sodium bicarbonate, and extract three times with dichloromethane. Concentrate the organic phase to obtain the crude product. The crude product C was recrystallized three times using a mixed solvent of methanol and water to obtain ethyl 4-(1,2,2-tristyrene)benzoate. 2.4252 g and 6.00 mmol of ethyl 4-(1,2,2-tristyrene)benzoate, 800 mg and 20.00 mmol of sodium hydroxide, 40 mL of tetrahydrofuran, and 40 mL of distilled water were added sequentially to a three-necked flask equipped with a condenser. The mixture was refluxed at 100 °C for 24 h. The system was cooled to 30 °C, and the pH of the reaction system was adjusted to 2 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed three times with distilled water and dried under vacuum at 120 °C for 16 h to obtain the crude product J. The crude product J was recrystallized three times using a mixed solvent of methanol and water to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 2.2587 g of 4-(1,2,2-tristyrene)benzoic acid (6.00 mmol) and 80 mL of tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred to dissolve. The reaction system was cooled to 0°C, and 1.9038 g of oxaloyl chloride (15.00 mmol) was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxaloyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2°C for later use. 0.6007 g and 2.60 mmol of diamine ODA, 0.3662 g and 1.40 mmol of hydroxyl-containing diamine APAF, 2.0820 g and 4.00 mmol of diacid anhydride BPADA, 0.9770 g and 8.00 mmol of benzoic acid, and 30 mL of m-cresol were added sequentially to a three-necked flask equipped with a mechanical stirrer. The mixture was reacted at 80 °C for 4 h. Four drops of isoquinoline were added, and the reaction system was heated to 200 °C and the reaction was continued for 20 h. The reaction system was cooled to 25 °C, and the reaction solution was slowly precipitated in ethanol to obtain a fibrous polymer. The polymer was washed three times with ethanol and dried under vacuum at 100 °C for 16 h to obtain hydroxyl-containing polyimide T. Add 2.3694 g and 6.00 mmol of TPE-COCl, 1.5179 g and 15.00 mmol of triethylamine and 80 mL of tetrahydrofuran to a three-necked flask containing a magnetic inlet, stir to dissolve, and cool the reaction system. Polyimide T was dissolved in 120 mL of THF to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to 0°C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at 0°C for 4 h. The system was heated to reflux and the reaction was continued for 16 h. The reaction solution was cooled to 25°C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 14 h, and finally dried under vacuum at 120°C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMAC, then cast into a petri dish and allowed to stand at 70°C for 24 h to evaporate the solvent. The temperature was then raised to 180°C and dried under vacuum for 4 h. After the temperature dropped to 30°C, the film was removed to obtain a polyimide film with photoluminescent properties.

3. A method for preparing a polyimide film with aggregation-induced emission effect, characterized in that: To a single-necked round-bottom flask equipped with a magnetic inlet, add 1.3410 g and 4.00 mmol of bromotriphenylene, 0.9700 g and 5.00 mmol of 4-(ethoxycarbonyl)phenylboronic acid, 4.7696 g and 45.00 mol of Na₂CO₃, 0.2888 g and 0.25 mmol of tetrakis(triphenylphosphine)palladium, 100.0 mL of toluene, 20.0 mL of ethanol, and 20.0 mL of distilled water sequentially. Reflux the mixture at 110 °C for 12 h. Cool the reaction mixture to 25 °C, precipitate the mixture in an aqueous solution of sodium bicarbonate, and extract three times with dichloromethane. Concentrate the organic phase to obtain the crude product. The crude product C was recrystallized three times using a mixed solvent of ethanol and water to obtain ethyl 4-(1,2,2-tristyrene)benzoate. 1.6168 g and 4.00 mmol of ethyl 4-(1,2,2-tristyrene)benzoate, 480 mg and 12.00 mmol of sodium hydroxide, 20 mL of tetrahydrofuran, and 20 mL of distilled water were added sequentially to a three-necked flask equipped with a condenser. The mixture was refluxed at 90 °C for 24 h. The system was cooled to 25 °C, and the pH of the reaction system was adjusted to 3 with an acid solution. The tetrahydrofuran was concentrated to remove the solid, resulting in a white solid. The solid was filtered, and the filter cake was collected. The filter cake was washed twice with distilled water and dried under vacuum at 120 °C for 12 h to obtain the crude product J. The crude product J was recrystallized twice using a mixed solvent of methanol and water to obtain 4-(1,2,2-tristyrene)benzoic acid, a carboxylic acid compound containing the TPE motif. 1.5058 g of 4.00 mmol of 4-(1,2,2-tristyrene)benzoic acid and 40 mL of tetrahydrofuran were added to a single-necked flask equipped with a magnetic stir bar and stirred to dissolve. The reaction system was cooled to 5 °C, and 0.9519 g of 7.50 mmol of oxaloyl chloride was added. The reaction was stirred for another 16 h. The reaction system was concentrated to remove tetrahydrofuran and excess oxaloyl chloride, yielding TPE-COCl. The single-necked flask was sealed and stored at 2 °C for later use. 0.2002 g and 1.00 mmol of diamine ODA, 0.3662 g and 1.00 mmol of hydroxyl-containing diamine APAF, 0.8885 g and 2.00 mmol of diacid anhydride BPADA, 0.4885 g and 4.00 mmol of benzoic acid, and 11 mL of m-cresol were added sequentially to a three-necked flask equipped with a mechanical stirrer. The mixture was reacted at 85 °C for 4 h. Three drops of isoquinoline were added, and the reaction mixture was heated to 190 °C and reacted for another 18 h. The reaction mixture was cooled to 30 °C, and the reaction solution was slowly precipitated in ethanol to obtain a fibrous polymer. The polymer was washed three times with ethanol and dried under vacuum at 120 °C for 12 h to obtain hydroxyl-containing polyimide T. Add 1.5796 g and 4.00 mmol of TPE-COCl, 0.8095 g and 8.00 mmol of triethylamine and 40 mL of tetrahydrofuran to a three-necked flask equipped with a magnetic induction magnet, stir to dissolve, and cool the reaction system. Polyimide T was dissolved in 80 mL of THF to obtain a tetrahydrofuran solution of polyimide T. When the system was cooled to 0 °C, the tetrahydrofuran solution of polyimide T was added, and the reaction was continued at 0 °C for 4 h. The system was heated to reflux and the reaction was continued for 16 h. The reaction solution was cooled to 25 °C, and the reaction solution was poured into methanol for precipitation to obtain a fibrous polymer. The polymer was washed three times with methanol and then three times with distilled water to obtain polymer Z. Polymer Z was subjected to Soxhlet extraction with methanol for 16 h, and finally dried under vacuum at 100 °C to obtain polymer E containing TPE units. The polyimide containing TPE units was dissolved in DMAC, then cast into a petri dish and allowed to stand at 70 °C for 16 h to evaporate the solvent. The temperature was then raised to 140 °C and dried under vacuum for 5 h. After the temperature dropped to 25 °C, the film was removed to obtain a polyimide film with photoluminescent properties.

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