Polyimide, alicyclic dianhydride containing ether group, and synthesis method thereof

Abstract

The present disclosre provides a polyimide, an alicyclic dianhydride containing ether group, and synthesis method thereof. The alicyclic dianhydride containing ether group has a structure of the following formula (I), formula (II), or formula (III): , wherein R

Description

Polyimide, ether-containing alicyclic dianhydride and synthesis method thereof The present disclosure relates to a polyimide, an ether-containing alicyclic dianhydride, and a method for synthesizing the ether-containing alicyclic dianhydride. Polyimide (PI) is a polymer material with excellent thermal and mechanical properties, making it widely used in industry. With the development of the optoelectronics industry, traditional aromatic polyimides are often colored, making them unsuitable for the preparation of colorless and transparent optical films. Alicyclic polyimides, due to their lower charge transfer forces in their structures, produce films with better light transmittance and colorlessness than aromatic polyimides, making them a more suitable material. However, the synthesis process of the alicyclic monomers used to make alicyclic polyimides is prone to the production of isomers and other byproducts, making the isolation, purification, and configuration determination of the compounds difficult. Consequently, alicyclic polyimides are limited by the type of monomers available, making monomer design and synthesis one of the most critical steps in the development of alicyclic polyimides. In view of the above, how to provide a novel alicyclic monomer to improve the aforementioned defects, or at least provide an alternative solution, is an urgent problem to be solved. To address the current challenges of traditional aromatic polyimides, which are limited in their application in transparent optical films due to their coloration, and the difficulties encountered in isolating and purifying the alicyclic monomers and determining their configurations, the present invention utilizes a novel synthetic pathway to develop a novel ether-based alicyclic dianhydride monomer. This monomer is then used to successfully synthesize a polyimide exhibiting excellent thermal stability, solubility, processability, and colorless, transparent films. The present disclosure provides an ether-containing alicyclic dianhydride having the following structure: Formula (I), Formula (II), Formula (III), wherein R 1. R 2. R 3. R 4. R 5. R 6 independently include C1 to C5 hydrocarbon groups. The present disclosure further provides a method for synthesizing an ether-containing alicyclic dianhydride, which comprises the following steps: subjecting compound 1a to a methoxycarbonylation reaction to obtain compound 1b, and subjecting compound 1b to a hydrolysis and dehydration reaction to obtain an ether-containing alicyclic dianhydride having formula (I): Compound 1a Compound 1b Formula (I), wherein R 1. R 2 independently includes C1 to C5 hydrocarbon groups; alternatively, compound 2a is subjected to a methoxycarbonylation reaction to obtain compound 2b, and compound 2b is subjected to a hydrolysis and dehydration reaction to obtain an ether-containing alicyclic dianhydride having formula (II) Compound 2a Compound 2b Formula (II), wherein R 3. R 4 independently includes a C1 to C5 hydrocarbon group; alternatively, compound 3a is subjected to a methoxycarbonylation reaction to obtain compound 3b, and compound 3b is subjected to a hydrolysis and dehydration reaction to obtain an ether-containing alicyclic dianhydride having formula (III): Compound 3a Compound 3b Formula (III), wherein R 5. R 6 independently include C1 to C5 hydrocarbon groups. The present disclosure further provides a polyimide having a structure of the following formula (IV), formula (V), formula (VI), formula (VII), formula (VIII), or formula (IX): Formula (IV), Formula (V), Formula (VI), Formula (VII), Formula (VIII), Formula (IX), wherein R 1. R 2. R 3. R 4. R 5 and R 6 independently include C1 to C5 hydrocarbon groups, R 7 and R 8 independently include aromatic groups, aliphatic groups, aromatic groups and Combination of, or aliphatic group and A combination of R R is a moiety independently selected from the group consisting of a substituted or unsubstituted aromatic group, a heterocyclic aromatic group, and an aliphatic group, 10 An aromatic group or an aliphatic group is included, and n is a positive integer from 1 to 500. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the disclosure as claimed. For ease of understanding and reading, the following will first describe the synthesis of alicyclic monomers from a series of ether-containing alicyclic dianhydrides, followed by the synthesis of alicyclic polyimides from these ether-containing alicyclic dianhydrides. It should be noted that the synthetic pathways provided herein are only one or more of all possible pathways. However, all possible production pathways for alicyclic dianhydrides or polyimides with the same or similar structures as those provided herein are encompassed by this disclosure. The present disclosure provides an ether-containing alicyclic dianhydride and a method for synthesizing the same. Specifically, the ether-containing alicyclic dianhydride has the following structure: Formula (I), Formula (II), Formula (III), wherein R 1. R 2. R 3. R 4. R 5. R 6 independently include C1 to C5 hydrocarbon groups. In detail, the synthesis method of the ether-containing alicyclic dianhydride having a structure of formula (I) comprises subjecting compound 1a to a methoxycarbonylation reaction to obtain compound 1b, and subjecting compound 1b to a hydrolysis and dehydration reaction to obtain the ether-containing alicyclic dianhydride having formula (I) Compound 1a Compound 1b. In some embodiments, compound 1a is obtained by subjecting compound 1c to a Williamson ether synthesis reaction, wherein the Williamson ether synthesis reaction comprises adding an alkyl halide, wherein the alkyl halide comprises a C1 to C5 alkyl halide, and compound 1c has the structure shown below: Compound 1c. For example, the ether-containing alicyclic dianhydride having the structure of formula (I) can be (Compound 1-1). For another example, the ether-containing alicyclic dianhydride having the structure of formula (I) can be (Compound 1-2). In detail, the synthesis method of the ether-containing alicyclic dianhydride having a structure of formula (II) comprises subjecting compound 2a to a methoxycarbonylation reaction to obtain compound 2b, and subjecting compound 2b to a hydrolysis and dehydration reaction to obtain the ether-containing alicyclic dianhydride having formula (II), wherein compound 2a has the structure shown below: , compound 2b has the structure shown below: . In some embodiments, compound 2a is obtained by subjecting compound 2c to a Williamson ether synthesis reaction, and the Williamson ether synthesis reaction comprises adding an alkyl halide, wherein the alkyl halide comprises a C1 to C5 alkyl halide. For example, the ether-containing alicyclic dianhydride having the structure of formula (II) can be (Compound 2). In detail, the synthesis method of the ether-containing alicyclic dianhydride having a structure of formula (III) comprises subjecting compound 3a to a methoxycarbonylation reaction to obtain compound 3b, and subjecting compound 3b to a hydrolysis and dehydration reaction to obtain the ether-containing alicyclic dianhydride having formula (III), wherein compound 3a has the structure shown below: , compound 3b has the structure shown below: . In some embodiments, compound 3a is obtained by subjecting compound 3c to oxidation and alkylation, and the alkylation reaction includes adding an alkyl halide, wherein the alkyl halide includes a C1 to C5 alkyl halide, wherein compound 3c has the structure shown below: . For example, the ether-containing alicyclic dianhydride having the structure of formula (III) can be (Compound 3). The present disclosure further provides a polyimide polymer. Specifically, the present disclosure provides a polyimide polymer derived from the aforementioned ether-containing alicyclic dianhydride monomer, having a structure of the following formula (IV), formula (V), formula (VI), formula (VII), formula (VIII), or formula (IX): Formula (IV), Formula (V), Formula (VI), Formula (VII), Formula (VIII), Formula (IX), wherein R 1. R 2. R 3. R 4. R 5 and R 6 independently include C1 to C5 hydrocarbon groups, R 7 and R 8 independently include aromatic groups, aliphatic groups, aromatic groups and Combination of, or aliphatic group and A combination of R R is a moiety independently selected from the group consisting of a substituted or unsubstituted aromatic group, a heterocyclic aromatic group, and an aliphatic group, 10 An aromatic group or an aliphatic group is included, and n is a positive integer from 1 to 500. The following examples are provided to illustrate specific aspects of the present disclosure and to enable those skilled in the art to practice the present disclosure. Although the following examples are described, the materials used, their amounts and ratios, processing details, and process flows may be appropriately varied without exceeding the scope of the present disclosure. Therefore, the present disclosure should not be construed in a limiting sense based on the examples described below. Please refer to the flowchart in Figure 1 for details of the preparation of the aforementioned ether-containing alicyclic dianhydride monomers of Formula (I), Formula (II), and Formula (III), as well as the structures of the intermediate compounds produced in each step. For example, a preferred embodiment of the present disclosure primarily provides a series of three ether-containing alicyclic dianhydride monomers, including 1-1, 1-2, 2, and 3, as shown in Figure 1 , having the stereoisomeric structural characteristics of Compounds 1-1, 1-2, 2, and 3. Synthesis of compound 1c( cis-OH) and compound 2c ( trans-OH): A 500mL three-necked flask with a dosing tube, mechanical stirring, and nitrogen was set up. The device was dried and dehydrated using a spray gun. After cooling, 4.2g (110.67 mmol) of lithium aluminum hydride (LAH) was added. Then, under an ice bath, 100mL of dry tetrahydrofuran (THF) was pumped into the dosing tube using a double-ended needle. The solution was slowly dripped into the reaction flask to form a suspension solution, and the ice bath was removed. Since dry THF still contains trace amounts of water, the reaction between lithium aluminum hydride and water will release a lot of heat. If the solution is not added slowly under an ice bath, some of the solvent will evaporate. Separately, prepare a 500 mL Erlenmeyer flask purged with nitrogen and add 8 g (33.29 mmol) of BQCP (compound 3c) to a solution completely dissolved in 200 mL of dry tetrahydrofuran. Use a double-ended needle to add this solution to the dosing tube. Stir at high speed and slowly add 10 mL of the solution dropwise to the three-necked flask at 30-second intervals. Stir the colloidal suspension vigorously for 12 hours. After 12 hours, prepare a saturated aqueous solution of ammonium chloride (NH 4Cl (aq) Terminate the reaction. Add 1-2 drops every few minutes to the three-necked flask until no gas escapes. Allow the remaining lithium aluminum hydride in the flask to react with the ammonium chloride solution, eventually forming a white to gray suspension. Continue stirring for half an hour. Be extremely careful in this step; if the ammonium chloride solution is added too quickly, the reaction can be so vigorous that the tetrahydrofuran boils, and a large amount of hydrogen will be produced during the reaction. The suspension was then poured into a beaker, supplemented with about 200 mL of tetrahydrofuran, heated to 50°C and stirred for 20 minutes. The suspension was then filtered under vacuum to collect the lower filtrate while hot, and the solvent was concentrated under reduced pressure to dryness. The product was then washed with deionized water and n-hexane, and the upper solid was collected by vacuum filtration to obtain compound 1c ( cis-OH) and compound 2c ( This mixture can be washed and filtered with a vacuum at a ratio of 1 g solid to 50 mL ethyl acetate. The white solid remaining on the filter cake is compound 1c ( cis-OH), and after the washed ethyl acetate filtrate is dried, a trace amount of compound 1c ( cis-OH) and compound 2c ( The filter cake on the upper layer after the first filtration was poured back into the beaker and added with about 500 mL of tetrahydrofuran. The mixture was heated to 50°C and stirred for 20 minutes. The above purification steps were repeated to obtain almost pure compound 1c ( cis-OH) white solid. If there is still a trace of compound 2c ( trans-OH), compound 2c can be washed with ethyl acetate using the same method as above ( The product is heated and stirred twice in tetrahydrofuran to separate from the suspended solid impurities and dissolve in the solvent. Compound 1c ( cis-OH) and compound 2c ( trans-OH) was recrystallized 2 to 3 times through ethyl acetate (1 g of compound 2c ( trans-OH) / 20 mL ethyl acetate), and the precipitated fine white powder (compound 1c ( cis-OH) in a mixture with a relatively large proportion), leaving only most of the crystals and recrystallizing them once more, we can obtain compound 2c with a purity of 99% ( trans-OH) transparent crystals. Synthesis of compound 1a-1( cis-OMe): A 1L three-necked flask with nitrogen, a condenser and a magnetic stirrer was equipped, and 6.90 g (173.12 mmol) of 60% sodium hydride and 5.30 g (21.69 mmol) of compound 1c ( cis-OH) was dissolved in 550 mL of anhydrous tetrahydrofuran to form a white suspension. After refluxing at 80°C for 24 hours, about 50 mL of saturated aqueous ammonium chloride solution was added until the liquid was completely dissolved. Then, the mixture was extracted with saturated brine and tetrahydrofuran, and the organic layer was washed with saturated brine until neutral. The organic solution layer was collected and the solvent was removed by concentrating under reduced pressure with anhydrous magnesium sulfate to obtain a yellow-brown oily paste product. After drying in a vacuum high-temperature oven at 100°C, 5.90 g (21.66 mmol) of compound 1a-1 ( cis-OMe), with a yield of 99.9%. Synthesis of compound 1b-1( cis-OMeTE): 5.90 g (21.66 mmol) of compound 1a-1 ( cis-OMe), add 72 mL of anhydrous methanol, then add 20 mL of chloroform to make the liquids more miscible and form a mist. Then add 0.56 g (0.53 mmol) of 10% Pd / C and 19.87 g (147.79 mmol) of copper chloride in sequence, and lock the autoclave. Then connect a carbon monoxide cylinder and replace the nitrogen in the autoclave with carbon monoxide. After closing the vent valve, adjust the pressure to 4 kg / cm 2 The mixture was stirred vigorously at room temperature for 1 day. After the reaction, the carbon monoxide in the autoclave was slowly released until the pressure returned to atmospheric pressure and no more gas was discharged. The autoclave was opened and 30 mL of chloroform was added to the reaction flask and stirred for 15 minutes. The catalyst was removed by filtration with diatomaceous earth. The filtrate was collected and extracted with saturated brine and chloroform. The lower organic layer was collected and washed with saturated brine until neutral. After dehydration with anhydrous magnesium sulfate, chloroform was removed using a vacuum concentrator to obtain a yellow-brown ointment. A small amount of ether (about 5 mL) was added to the ointment and placed in a refrigerator for one night. Yellow-brown crystals precipitated at the bottom. After filtration, the product was rinsed with ice ether to obtain white transparent crystals. The filtrate was reacted again under the same conditions and dosage for 1 day. After extraction and precipitation with ether, white transparent crystals were obtained. A total of 4.50 g (8.85 mmol) of compound 1b-1 ( cis-OMeTE) with a total yield of 40.9%. If the product is still slightly yellow crystals after rinsing with glacial ether, it can be recrystallized from ethyl acetate to obtain white transparent crystals. Synthesis of compound 1-1( cis-OMeDA): The International Union of Pure and Applied Chemistry chemical nomenclature (IUPAC) name of compound 1-1 is: (3aR,4R,4aR,5S,5aR,6R,6aR,9aS,10S,10aS,11R,11aS,12S,12aS)-5,11-dimethoxydodecahydro-4,12:6,10-dimethanoanthra[2,3-c:6,7-c']difuran-1,3,7,9(3aH,9aH)-tetraone. A 50 mL three-necked round-bottom flask equipped with nitrogen, a dosing tube, a condenser and a magnetic stirrer was added in sequence with 1.05 g (2.06 mmol) of compound 1b-1 ( cis-OMeTE), 2mL formic acid, 2mL pure water and 0.4mL hydrochloric acid (37%), the reaction temperature was adjusted to 90 ° C, and the reaction was completely dissolved after 4 hours. After the reaction was completed, it was cooled to room temperature and an off-white solid was slowly precipitated. 8mL acetic anhydride was slowly dripped into the dosing tube to avoid sudden boiling. After the acetic anhydride was completely added, the temperature was adjusted to 120 ° C. After 12 hours of reaction, the reaction was cooled to room temperature. Subsequently, the condenser was replaced with a distillation tube and the dosing tube was removed. The solvent was completely evaporated to obtain a foaming yellow-white solid. A trace amount (about 2 mL) of acetic anhydride was added for recrystallization. After being placed in a vacuum oven at 200 ° C for 12 hours, 0.67g (1.61 mmol) of compound 1-1 ( cis-OMeDA), with a yield of 78.1%. Compound 1-1( cis-OMeDA) 1 The H NMR spectrum is shown in Figure 2A. 1 H 1 The H-COSY spectrum is shown in Figure 2B. 13 The C NMR spectrum is shown in Figure 2C. 13 C 1 The H-HSQC spectrum is shown in Figure 2D and the X-ray single crystal diffraction pattern is shown in Figure 2E. Compound 1-1( The melting point of compound 1-1 ( The NMR spectrum of cis-OMeDA is 1 H NMR (600 MHz, DMSO) δ 3.52 (d, J = 1.3 Hz, 2H), 3.42 (d, J= 3.7 Hz, 2H), 3.38 (s, 6H), 3.27 (d, J = 1.0 Hz, 2H), 2.80 (dd, J= 4.1, 2.0 Hz, 2H), 2.71 (s, 2H), 2.64 (s, 2H), 2.32 – 2.24 (m, 2H), 1.55 (d, J = 11.2 Hz, 1H), 1.43 (d, J = 11.4 Hz, 1H), 1.26 (d, J = 11.4 Hz, 1H), 1.17 (d, J = 11.2 Hz, 1H)". Compound 1-1( The NMR carbon spectrum of cis-OMeDA is 13 C NMR (150 MHz, DMSO, δ, ppm): 174.54, 174.05, 74.40, 56.45, 45.57, 43.57, 42.91, 42.63, 41.08, 37.58, 36.03, 34.63". Compound 1-1( The mass spectrum of cis-OMeDA is "EIMS (m / z): calcd for C 22 H 24 O 8, 416.2; found 416.2 [M] + . Anal. Calcd for C 26 H 36 O 10 : C, 63.45; H, 5.81; O, 30.74; found, C, 63.41; H, 5.86; O, 31.08". Synthesis of compound 1a-2( cis-OEt): A 500 mL three-necked flask equipped with a condenser, nitrogen, and magnetic stirring was added with 5 g (20.5 mmol) of compound 1c ( cis-OH) and 200mL tetrahydrofuran. Prepare a 50mL sample bottle, add 6.55g (163.9mmol) of 60% sodium hydride (NaH), rinse the mineral oil with n-hexane, and then use a water pump to drain the solvent. Then slowly add it to the three-necked flask in batches under an ice bath to form a white suspension solution. During the addition process, it must be noted that sodium hydride will react with water in tetrahydrofuran, which will release heat and produce hydrogen gas. It must be added slowly in batches. Then add 17.86g (163.9mmol) of bromoethane (CH 3CH 2Br) into a three-necked flask. Because ethyl bromide is volatile, it must be added directly to the solution to prevent the dosage from escaping. Then, the mixture was stirred in a closed reflux at 60°C for 2 days. After the reaction, a thin layer chromatography (TLC) sheet was placed and run with ethyl acetate (EA) / hexane (Hexane) = 1:5. Potassium permanganate colorimetric solution was used to confirm the TLC sheet. Compound 1a-2 ( cis-OEt) (R f =0.8) and the byproduct (R f =0.3), the starting material is in R f = 0.2. After cooling, add saturated aqueous ammonium chloride solution to terminate the reaction, and react the remaining sodium hydride in the three-necked flask until no bubbles escape. Then, the tetrahydrofuran solution was concentrated under reduced pressure and removed. At this time, a small amount of white solid starting compound 1c ( cis-OH) and yellow ointment mixture (compound 1a-2 ( The yellow ointment was dissolved in ether and then vacuum filtered to recover the starting material. The lower filtrate was collected and extracted with ether and saturated brine. The organic layer was washed with saturated brine until neutral, and then dehydrated with anhydrous magnesium sulfate. The filtrate was collected by vacuum filtration and concentrated under reduced pressure to remove the solvent to obtain a pale yellow liquid crude product. The yellow liquid crude product was then chromatographed with two thin layer chromatography sheets of short column height using the above-mentioned solvent ratio to separate the by-products. After drying in a vacuum oven at room temperature, 4 g of compound 1a-2 ( cis-OEt), 65% yield, 1.39 g of by-product, 25% yield, and 0.5 g of starting material. Synthesis of compound 1b-2( cis-OEtTE): A 250 mL glass container was placed in a nitrogen-filled autoclave, and 3 g (10 mmol) of compound 1a-2 ( cis-OEt), and then 92 mL (2.2 mol) of anhydrous methanol (MeOH), 11.61 g (80.64 mmol) of copper (II) chloride (CuCl 2) 0.3032g (0.285 mmol) of palladium on carbon (Pd / C) and 17.71g (161.2 mol) of anhydrous sodium acetate. The catalyst must be dehydrated at 100°C in a vacuum for more than 6 hours before use. When adding the palladium on carbon catalyst to the container, the stirring must be turned up high (350 rpm) and added slowly under nitrogen. Otherwise, there is a risk of fire when the palladium on carbon catalyst contacts methanol in the air. After the addition is completed, lock the autoclave and connect the carbon monoxide cylinder. Adjust the pressure to 2kg / cm 2 , slightly open the pressure relief valve for 15 minutes to replace the pressure in the autoclave with carbon monoxide, and then adjust the pressure to 3kg / cm 2 Observe the autoclave for half an hour to see if there is any leakage, and finally adjust the pressure to 4.5kg / cm 2 , and stirred at 380 rpm at room temperature for two days. After the reaction is completed, the carbon monoxide in the autoclave is slowly depressurized until the pressure returns to 1 atmosphere, and then the pressure relief valve is opened to the maximum until no gas is discharged. 50 mL of chloroform is added to the container and stirred for 15 minutes. The catalyst is then filtered through diatomaceous earth. The remaining filtrate is extracted with chloroform and saturated brine. The organic layer is washed with saturated brine until it is neutral. During the process, the organic layer, which is originally blue-green, will turn light yellow. As the number of extractions increases, the aqueous layer will change from blue-green to transparent and white mist. The organic layer is collected and anhydrous magnesium sulfate is added to remove water. The filtrate is collected by vacuum filtration and concentrated under reduced pressure to remove the solvent to obtain a pale yellow oily liquid crude product. The crude ointment was recrystallized by adding a small amount of ether (about 5 mL) and placed in a refrigerator overnight. The upper crystals were collected by vacuum filtration, and the lower filtrate was recovered and concentrated under reduced pressure to remove the solvent. The above recrystallization steps were repeated and dried in a vacuum oven at 70°C for 12 hours to obtain 2.07 g of white crystals of compound 1b-2 ( cis-OEtTE), yield 39%. Synthesis of compound 1-2( cis-OEtDA): The IUPAC name of compound 1-2 is: (3aR,4R,5S,6R,6aR,9aS,10S,11R,12S,12aS)-5,11-diethoxytetradecahydro-1H,3H-4,12:6,10-dimethanoanthra[2,3-c:6,7-c']difuran-1,3,7,9-tetraone. A 25 mL three-necked round-bottom flask equipped with nitrogen, a dosing tube, a condenser and a magnetic stirrer was added in sequence with 0.85 g (1.59 mmol) of compound 1b-2 ( cis-OEtTE), 1.5mL formic acid, 1.5mL pure water and 0.3mL hydrochloric acid (37%), the reaction temperature is adjusted to 90 ° C, and the reaction is completely dissolved after 4 hours. After the reaction is completed, white crystals will precipitate when it is cooled to room temperature. In addition, the upper crystals are filtered and dried in a 100 ° C high-temperature oven for one day to obtain white crystals. Then 4mL acetic anhydride is slowly dripped into the dosing tube to avoid sudden boiling. After the acetic anhydride is completely added, the temperature is adjusted to 120 ° C and the reaction is carried out for 12 hours. After the reaction is completed, the dosing tube and reflux pipe are removed, and a vacuum distillation apparatus is set up to distill most of the solvent. It is filtered and most of the acetic anhydride is washed with ether. It is placed in a 100 ° C high-temperature oven and dried for half a day to obtain 0.7 g of crude product compound 1-2 ( cis-OEtDA), yield 99.9%. The crude product was recrystallized in a nitrogen atmosphere at a ratio of 1 mL acetic anhydride to 1 g of crude product. After standing overnight, the product was filtered and rinsed with ether. The upper solid layer was collected and dried in a 140°C oven for one day to obtain 0.42 g of compound 1-2 ( cis-OEtDA), with a yield of 60%. The crude product can also be sublimed to remove color and impurities, and pure compound 1-2 ( cis-OEtDA) as a white powder. Compound 1-2( cis-OEtDA) 1 The H NMR spectrum is shown in Figure 3A. 1 H 1 The H-COSY spectrum is shown in Figure 3B. 13 The C NMR spectrum is shown in Figure 3C. 13 C 1 The H-HSQC spectrum is shown in Figure 3D and the X-ray single crystal diffraction pattern is shown in Figure 3E. Compound 1-2( The melting point of compound 1-2 ( The NMR spectrum of cis-OEtDA is 1 H NMR (600 MHz, DMSO- d 6 , δ, ppm): 3.68 (dq, J= 9.6, 7.0 Hz, 2H), 3.58 (m, 2H), 3.54 (d, J= 1.3 Hz, 2H), 3.54 (m, 2H), 3.44 (dq, J = 9.6, 7.0 Hz, 2H), 3.25 (d, J= 1.1 Hz, 2H), 2.74 (m, 2H), 2.69 (s, 2H), 2.64 (s, 2H), 2.26 (m, 2H), 1.53 (d, J = 11.1 Hz, 1H), 1.44 (d, J = 11.4 Hz, 1H), 1.27 (d, J = 11.3 Hz, 1H), 1.16 (t, J = 7.0Hz, 6H), 1.16 (m, 1H)". Compound 1-2 ( The NMR carbon spectrum of cis-OEtDA is 13 C NMR (150 MHz, DMSO- d 6 , δ, ppm): 175.08, 174.63, 72.80, 63.98, 46.06, 44.13, 43.49, 43.46, 41.63, 38.83, 36.49, 35.08, 31.15, 16.17". Compound 1-2 ( The mass spectrum of cis-OEtDA is [EIMS (m / z): calcd for C 24 H 28 O 8 + : 444; found 444 [M] + . Anal. calcd for C 24 H 28 O 8: C, 64.85; H, 6.35; O, 28.80; found, C, 64.25; H, 6.34; O, 29.29". Synthesis of compound 2a( trans-OMe): A 500 mL three-necked flask equipped with a condenser, nitrogen, and magnetic stirring was added with 2 g (8.2 mmol) of compound 2c ( Prepare a 50mL sample bottle and add 2.62g (65.6mmol) of sodium hydride (60%) (rinse the mineral oil with n-hexane, then use a water pump to drain the solvent, then slowly add it to the three-necked flask in batches under an ice bath to form a white suspension solution. During the addition process, it should be noted that sodium hydride will react with water in tetrahydrofuran, which will release heat and produce hydrogen. It must be added slowly in batches. Then add 9.3g (65.6mmol) of iodomethane (CH 3I) into a three-necked flask. Because iodomethane is volatile, it must be added directly to the solution to prevent the dosage from escaping. Then, stir under reflux at 60°C for half a day. After half a day, the reaction was confirmed to be complete by spotting the thin layer chromatography slide, and the slide was run with ethyl acetate (EA) / n-hexane (Hexane) = 1:5. Then, potassium permanganate colorimetric solution was used to confirm that there was only one spot on the thin layer chromatography slide (i.e., the R f = 0.5), after cooling, saturated aqueous ammonium chloride solution was added to terminate the reaction, and the remaining sodium hydride in the three-necked flask was reacted until no bubbles escaped. Then the tetrahydrofuran solution was concentrated under reduced pressure and removed, extracted with ether and saturated brine, the organic layer was washed with saturated brine until neutral, and then dehydrated with anhydrous magnesium sulfate. The filtrate was collected by vacuum filtration and concentrated under reduced pressure to remove the solvent to obtain a light yellow liquid product compound 2a ( After drying in a vacuum oven at room temperature, 2.22 g of compound 2a ( trans-OMe), yield 99.9%. Synthesis of compound 2b( trans-OMeTE): A 250 mL glass container was placed in a nitrogen-filled autoclave, and 2 g (7.35 mmol) of compound 2a ( trans-OMe), and then 67mL (1.46mol) of anhydrous methanol, 8.53g (63.47mmol) of copper (II) chloride, 0.223g (0.209mmol) of palladium carbon catalyst (Pd / C), and 13.01g (126.94mmol) of anhydrous sodium acetate were added in sequence. Before use, the catalyst must be dehydrated at 100°C in a vacuum for more than 6 hours. When adding the palladium carbon catalyst to the container, the stirring must be turned up high (350rpm) and added slowly under nitrogen, otherwise there is a risk of fire when the palladium carbon catalyst comes into contact with methanol in the air. After the addition is completed, lock the autoclave, connect the carbon monoxide cylinder, and adjust the pressure to 2kg / cm 2 , slightly open the pressure relief valve for 15 minutes to replace the pressure in the autoclave with carbon monoxide, and then adjust the pressure to 3kg / cm 2 Observe the autoclave for half an hour to see if there is any leakage, and finally adjust the pressure to 4.5kg / cm 2 , and stirred at 350 rpm at room temperature for two days. After the reaction is completed, the carbon monoxide in the autoclave is slowly depressurized until the pressure returns to one atmosphere, and then the pressure relief valve is opened to the maximum until no gas is discharged. After adding 50mL of chloroform to the container and stirring for 15 minutes, the catalyst is filtered through diatomaceous earth, and the remaining filtrate is extracted with chloroform and saturated brine. The organic layer is washed with saturated brine until it is neutral. During the process, the organic layer is originally blue-green and will turn light yellow. As the number of extractions increases, the water layer will change from blue-green to transparent and white mist. The organic layer is collected and anhydrous magnesium sulfate is added to remove water. The filtrate is collected by vacuum filtration and concentrated under reduced pressure to remove the solvent to obtain 3.8g of a light yellow ointment crude product of compound 2b ( trans-OMeTE) was dried in a vacuum oven at 50°C for 12 hours without purification and then directly used for the next reaction. Synthesis of compound 2b'( trans-OMeTA): A 100 mL three-necked flask with a reflux tube was set up and 3.8 g of compound 2b ( The crude trans-OMeTE product, 30 mL of methanol, and 30 mL of 2M aqueous sodium hydroxide solution were placed in a three-necked flask and stirred under reflux for 4 hours. The solution was initially turbid, but became clear after the reaction, with a small amount of salt precipitated. After the reaction is finished and cooled, the by-product of the previous autoclave in the water layer is extracted with ethyl acetate twice, leaving the water layer and slowly adding 12M hydrogen chloride under an ice bath until the solution is neutral, remove the ice bath, continue to add 12M hydrogen chloride at room temperature until weakly acidic (widely used test paper presents pink), and gradually a white precipitate is precipitated during the process, and stirred at 50 ° C for 15 minutes. Then saturated brine is added and extracted twice with a large amount of ethyl acetate (500mL in total). The white precipitate will dissolve in the organic layer, and the organic layer color will turn light yellow. It is not necessary to extract the organic layer to neutrality. The organic layer is directly collected and added with anhydrous magnesium sulfate to remove water. The filtrate is collected by suction filtration and concentrated under reduced pressure to remove the solvent to obtain a white solid crude product containing yellow ointment. The crude product can be added with a little glacial ethyl acetate (about 10mL) and taken to the vibration machine for a few minutes. Most of the ointment will dissolve in ethyl acetate, and then the upper solid is collected by suction filtration. 1.86g of white solid compound 2b' ( After purification, the total yield of the hydrolysis reaction from the previous autoclave step to this step was estimated to be 55%. Synthesis of compound 2( trans-OMeDA): The IUPAC name of compound 2 is: (3a R,4 R,4a R,5 R,5a R,6 R,6a R,9a S,10 S,10a S,11 S,11a S,12 S,12a S)-5,11-dimethoxytetradecahydro-1H,3H-4,12:6,10-dimethanoanthra[2,3-c:6,7-c']difuran-1,3,7,9-tetraone. In a 25 mL three-necked flask equipped with a reflux tube, a dosing tube, nitrogen, and a magnetic stirrer, 3.72 g (6.24 mmol) of compound 2b' ( 1. Add trans-OMeTA) to a three-necked flask, then slowly add 8 mL of acetic anhydride using a dosing tube. Be very careful in this step, as adding acetic anhydride too quickly can cause sudden boiling. The reaction mixture is then heated to 120°C and stirred under reflux for 12 hours. After the reaction is complete, remove the dosing and reflux lines and set up a vacuum distillation apparatus to distill off most of the acetic anhydride, leaving a small amount (approximately 0.5 ml). After cooling, a large amount of white solid will precipitate. If no solid precipitates after cooling, increase the temperature and distill off more solvent. Alternatively, add one or two drops of acetic acid (por solvent) before cooling to cause the anhydride solid to crystallize. If the precipitated product (1g) has a very dark color, it can be recrystallized with a mixed solution of acetic acid and acetic anhydride (1mL, ratio of 1:1) under nitrogen (note that too much nitrogen will dry up the solvent). After standing for half a day, many crystals can be seen growing. It is vacuum filtered and the acetic anhydride is washed away with ether. The upper crystals are collected and finally 2.46g of compound 2 ( The recrystallization yield was 72%. Compound 2 ( trans-OMeDA) 1 The H NMR spectrum is shown in Figure 4A. 13 The C NMR spectrum is shown in Figure 4B. 13 C 1 The H-HSQC spectrum is shown in Figure 4C, the EI-MASS spectrum is shown in Figure 4D, and the X-ray single crystal diffraction pattern is shown in Figure 4E. Compound 2 ( The melting point of compound 2 (trans-OMeDA) is 147°C. The NMR hydrogen spectrum of trans-OMeDA) is 1 H NMR (600 MHz, DMSO- d 6 , δ, ppm): δ3.93 (broad, 2H), 3.71 (s, 2H), 3.42(s, 6H), 3.15 (m, 2H), 2.98 (s, 2H), 2.91 (s, 2H), 2.51 (broad, 2H), 2.31 (broad, 2H), 1.56 (broad, 2H), 1.43 (d, J = 9.7 Hz, 2H)". Compound 2 ( The NMR carbon spectrum of trans-OMeDA) is 13 C NMR (150 MHz, DMSO- d 6 , δ, ppm): 173.45, 166.42, 57.19, 45.75, 44.53, 44.29, 43.36, 41.58, 41.58, 36.91". Compound 2 ( The mass spectrum of trans-OMeDA) is "EI MS (m / z): calcd for C 22 H 24 O 8 + : 416; found 416 [M] + . Anal. calcd for C 22 H 24 O 8: C, 63.45; H, 5.81; O, 30.74; found, C, 62.92; H, 5.77; O, 30.64". Synthesis of compound 3a (PhOMe): Apparatus 1: In a 500 mL three-necked round-bottom flask equipped with a magnetic stirrer, 7.9956 g (33.27 mmol) of compound 3c (BQCP) was added and dissolved in 200 mL of tetrahydrofuran at room temperature. After adding 4.5001 g (40.10 mmol) of potassium tert-butoxide and stirring for 2 hours, 12.5748 g (112.06 mmol) of potassium tert-butoxide was added. After two hours of reaction, 19.2309 g (135.49 mmol) of iodomethane was slowly added dropwise through the dosing tube at a rate of approximately one drop per second and allowed to react for 12 hours. After completion of the reaction, the mixture was extracted with ethyl acetate / saturated brine. The organic layer was washed until neutral, collected, and dehydrated with anhydrous magnesium sulfate. After concentration under reduced pressure, the mixture was dried in a vacuum oven at room temperature for 12 hours, yielding 5.4012 g of a crude brown solid (crude yield 60.9%). A small amount of ethanol was added to the resulting crude brown solid and vigorously stirred in an ice bath for approximately half an hour. The brown impurities will dissolve in ethanol, and the target product, Compound 3a (PhOMe), will precipitate. The white solid will be collected by filtration and rinsed with a small amount of icy ethanol. Dry in a vacuum oven at room temperature for 12 hours to obtain 4.2298 g of Compound 3a (PhOMe) as a white solid, with a yield of 47.7%. Synthesis of compound 3b (PhOMeTE): A 200 mL glass container was placed in a nitrogen-filled autoclave, and 2.66 g (10 mmol) of compound 3a (PhOMe) was added. Then, 92 mL (2.2 mol) of anhydrous methanol, 11.61 g (80.64 mmol) of copper (II) chloride, 0.3032 g (0.285 mmol) of palladium-carbon catalyst (10%), and 17.71 g (161.2 mol) of anhydrous sodium acetate were added in that order. Before use, the 10% palladium-carbon catalyst must be vacuum-dehydrated at 100°C for more than 6 hours to ensure anhydrous conditions, and then slowly added under nitrogen. After the addition is complete, lock the autoclave and connect the carbon monoxide cylinder. Adjust the inlet carbon monoxide pressure to 2 kg / cm 2 , and slightly open the pressure relief valve for 15 minutes to replace the inside of the autoclave with carbon monoxide. After the ventilation is completed, adjust the pressure to 5kg / cm 2 The reaction was stirred vigorously at 550 rpm at room temperature for two days. Synthesis of compound 3 (PhOMeDA): The IUPAC name of compound 3 is: tetramethyl (1R,2S,3R,4S,5S,6R,7S,8R)-9,10-dimethoxy-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracene-2,3,6,7-tetracarboxylate. A 25 mL three-necked round-bottom flask equipped with nitrogen, a dosing tube, a condenser, and magnetic stirring was added sequentially to 0.80 g (1.59 mmol) of compound 3b (PhOMeTE), 1.5 mL of formic acid, 1.5 mL of purified water, and 0.3 mL of 37% hydrochloric acid. The reaction temperature was adjusted to 90°C and allowed to react for 4 hours until complete dissolution occurred. After the reaction was completed, white crystals precipitated after cooling to room temperature. The upper layer of crystals was filtered and dried in a 100°C oven for one day to obtain white crystals. Then, 4 mL of acetic anhydride was slowly added dropwise through the dosing tube to prevent sudden boiling. After complete addition of the acetic anhydride, the temperature was adjusted to 120°C and the reaction was continued for 12 hours. After the reaction, the dosing and reflux lines were removed, and a vacuum distillation apparatus was set up to distil most of the solvent. The product was then vacuum filtered, and most of the acetic anhydride was washed with ether. The product was then dried in a 100°C oven for half a day to obtain 0.35 g of crude compound 3 (PhOMeDA), with a yield of 53.7%. The crude product was recrystallized under nitrogen with 1 mL of acetic anhydride per 1 g of crude product. The product was cooled to room temperature and allowed to stand overnight. The solid layer was collected by vacuum filtration and rinsed with ether. After drying in a vacuum oven at 140°C for one day, 0.279 g of compound 3 (PhOMeDA) was obtained as white crystals, with a yield of 42.8%. Synthetic polyimide polymer: A 25mL three-necked flask was equipped with a mechanical stirrer, condenser, and nitrogen flow. All monomers, solvents, and catalysts were dried in a vacuum oven or purified by vacuum distillation to remove water. All diamines and dianhydrides used in the synthesis of polyimide polymers were synthesized in a 1:1 molar ratio. The following is a polyimide polymer synthesis of the ether-containing alicyclic dianhydride monomers of Compound 1-1, Compound 1-2, and Compound 2 obtained in the present disclosure. The dianhydride monomer can be synthesized using any aromatic diamine or aliphatic diamine, for example, 4,4'-diaminodiphenyl ether (4,4'-oxydianiline, ODA), 2,2'-bis(trifluoromethyl)benzidine (TFMB), 9,9-bis(4-aminophenyl)fluorene (FDA), and p-phenylenediamine (PPD). According to the above synthesis steps, the ether-containing alicyclic dianhydride-derived polyimide polymer was synthesized, and the results were shown in Table 1 below through gel permeation chromatography (GPC). The viscosity ( η) is the intrinsic viscosity of the sample measured at 35°C at a concentration of 0.5 g / dL in N-methylpyrrolidone (NMP); Mw is the weight-average molecular weight determined by GPC in N,N-dimethylacetamide (DMAc) relative to a polystyrene standard; Mn is the number-average molecular weight determined by GPC in N,N-dimethylacetamide (DMAc) relative to a polystyrene standard; PDI is the polydispersity index, calculated as Mw / Mn. Table 1 Next, the solubility test results for the polyimide polymer derived from an ether-containing alicyclic dianhydride are shown in Table 2 below. Specifically, the solubility test was performed using 20 mg of sample in 1 mL of solvent and stirring. The symbol "++" indicates solubility at room temperature; the symbol "+" indicates solubility upon heating; and the symbol "-" indicates insolubility upon heating. Table 2 The thermal stability of polyimide polymers derived from ether-containing alicyclic dianhydrides was tested, and the results are shown in Table 3 below. The thermal expansion coefficient was measured in the range of 50°C to 150°C, and the glass transition temperature was measured by thermal mechanical analysis (TMA). Table 3 FIG5 shows the thermogravimetric analysis (TGA) results of the polyimide polymers derived from ether-containing alicyclic dianhydride according to Examples 1 to 12 of the present disclosure. Synthesis of polyimide films derived from cycloaliphatic dianhydrides containing ether groups: Polyimide polymer was dissolved in N,N-dimethylacetamide (DMAc) at a solids content of approximately 4% (w / v). After filtering through a 0.45μm Teflon filter, the solution was cast onto a Petri dish treated with isopropyl alcohol. After degassing, the film was baked in a circulating oven at 60°C for 6 hours, then 160°C for 3 hours, then 100°C for 0.5 hours, then 60°C for 0.5 hours. The film was gently removed from the Petri dish and then dried in a vacuum oven at 200°C to ensure complete removal of the solvent. A transparent polyimide polymer film with a thickness ranging from approximately 10 to 30 μm was obtained. The various embodiments of the present disclosure were prepared using the above-mentioned film synthesis method to form polyimide films derived from ether-containing alicyclic dianhydrides. The optical property test results of the polyimide films derived from ether-containing alicyclic dianhydrides of the various embodiments of the present disclosure are listed in Table 4 below, where λ 80% Represents the wavelength at which the film transmittance is 80%, λ cut-off Represents the wavelength when the film transmittance is less than 1%, T 400 It represents the transmittance at a wavelength of 400nm. Table 4 The UV-visible spectra and the Fourier transform infrared spectra of the polyimide films derived from the ether-containing alicyclic dianhydride of Examples 1 to 10 of the present disclosure are shown in FIG6 and FIG7 , respectively. Although the present disclosure has been described in considerable detail with reference to certain embodiments, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein. It will be apparent to those skilled in the art that various modifications and variations may be made to the structure of the present disclosure without departing from the scope or spirit of the present disclosure. In view of the foregoing, the present disclosure is intended to cover modifications and variations of the present disclosure that fall within the scope of the appended patent claims. 1a-1: Compound 1a-2: Compound 1b-1: Compound 1b-2: Compound 1c: Compound 1-1: Compound 1-2: Compound 2a: Compound 2b: Compound 2b': Compound 2c: Compound 2: Compound 3a: Compound 3b: Compound 3c: Compound 3: Compound A: Compound E1: Example 1 E2: Example 2 E3: Example 3 E4: Example 4 E5: Example 5 E6: Example 6 E7: Example 7 E8: Example 8 E9: Example 9 E10: Example 10 E11: Example 11 E12: Example 12 By reading the detailed description of the following embodiments and referring to the accompanying drawings, you can more fully understand the present disclosure. Figure 1 is a schematic diagram of the synthesis process of the ether-containing alicyclic dianhydride series monomers according to the present disclosure. Figures 2A, 2B, 2C, 2D and 2E are respectively the steps of ... 1 H NMR spectrum, 1 H 1 H-COSY spectrum, 13 C NMR spectrum, 13 C 1 H-HSQC spectrum and X-ray single crystal diffraction pattern. Figure 3A, Figure 3B, Figure 3C, Figure 3D and Figure 3E are the graphs of compound 1-2 in Figure 1. 1 H NMR spectrum, 1 H 1 H-COSY spectrum, 13 C NMR spectrum, 13 C 1 H-HSQC spectrum and X-ray single crystal diffraction pattern. Figure 4A, Figure 4B, Figure 4C, Figure 4D and Figure 4E are the graphs of compound 2 in Figure 1. 1 H NMR spectrum, 13 C NMR spectrum, 13 C 1 H-HSQC spectrum, EI-MASS spectrum, and X-ray single crystal diffraction pattern. Figure 5 is a thermogravimetric analysis (TGA) spectrum of polyimide derived from ether-containing alicyclic dianhydride according to various embodiments of the present disclosure. Figure 6 is a UV-visible spectrum of polyimide films derived from ether-containing alicyclic dianhydride according to various embodiments of the present disclosure. Figure 7 is a Fourier transform infrared spectrum of polyimide films derived from ether-containing alicyclic dianhydride according to various embodiments of the present disclosure. Domestic deposit information (please note in the order of deposit organization, date, and number) None Foreign deposit information (please note in the order of deposit country, organization, date, and number) None 1a-1: Compound 1a-2: Compound 1b-1: Compound 1b-2: Compound 1c: Compound 1-1: Compound 1-2: Compound 2a: Compound 2b: Compound 2b': Compound 2c: Compound 2: Compound 3a: Compound 3b: Compound 3c: Compound 3: Compound A: Compound

Claims

1. An ether-containing alicyclic dianhydride having a structure of the following formula (I), formula (II), or formula (III): Formula (I), Formula (II), Formula (III), wherein R 1、R 2、R 3、R 4、R 5、R 6 independently include C1 to C5 hydrocarbon groups.

2. The ether-containing alicyclic dianhydride as described in claim 1, wherein the ether-containing alicyclic dianhydride is 。 3. The ether-containing alicyclic dianhydride as described in claim 1, wherein the ether-containing alicyclic dianhydride is 。 4. The ether-containing alicyclic dianhydride as described in claim 1, wherein the ether-containing alicyclic dianhydride is 。 5. The ether-containing alicyclic dianhydride as described in claim 1, wherein the ether-containing alicyclic dianhydride is 。 6. A method for synthesizing an ether-containing alicyclic dianhydride comprises: Compound 1a is subjected to a methoxycarbonylation reaction to obtain compound 1b, and compound 1b is subjected to a hydrolysis and dehydration reaction to obtain an ether-containing alicyclic dianhydride having formula (I), Compound 1a Compound 1b Formula (I), wherein R 1、R 2 independently includes a C1 to C5 hydrocarbon group; or compound 2a is subjected to a methoxycarbonylation reaction to obtain compound 2b, and compound 2b is subjected to a hydrolysis and dehydration reaction to obtain an ether-containing alicyclic dianhydride having formula (II), Compound 2a Compound 2b Formula (II), wherein R 3、R 4 independently includes C1 to C5 hydrocarbon groups; or compound 3a is subjected to a methoxycarbonylation reaction to obtain compound 3b, and compound 3b is subjected to a hydrolysis and dehydration reaction to obtain an ether-containing alicyclic dianhydride having formula (III) Compound 3a Compound 3b Formula (III), wherein R 5、R 6 independently include C1 to C5 hydrocarbon groups.

7. The method for synthesizing an ether-containing alicyclic dianhydride as described in claim 6, wherein compound 1a is obtained by subjecting compound 1c to a Williamson ether synthesis reaction, and the Williamson ether synthesis reaction includes adding an alkyl halide, wherein the alkyl halide includes a C1 to C5 alkyl halide, and compound 1c has the structure shown below: 。 8. The method for synthesizing an ether-containing alicyclic dianhydride according to claim 6, wherein compound 2a is obtained by subjecting compound 2c to a Williamson ether synthesis reaction, and the Williamson ether synthesis reaction includes adding an alkyl halide, wherein the alkyl halide comprises a C1 to C5 alkyl halide, and compound 2c has the structure shown below: 。 9. A polyimide having a structure of the following formula (IV), formula (VI), or formula (VIII): Formula (IV), Formula (VI), Formula (VIII), wherein R 1、R 2、R 3、R 4、R 5 and R 6 independently include C1 to C5 hydrocarbon groups, R 7 and R 8 independently include aromatic groups, aliphatic groups, aromatic groups and Combination of, or aliphatic group and A combination of R R is a moiety independently selected from the group consisting of a substituted or unsubstituted aromatic group, a heterocyclic aromatic group, and an aliphatic group, 10 An aromatic group or an aliphatic group is included, and n is a positive integer from 1 to 500.

10. A polyimide having a structure of the following formula (V), formula (VII), or formula (IX): Formula (V), Formula (VII), Formula (IX), wherein R 1、R 2、R 3、R 4、R 5 and R 6 independently include C1 to C5 hydrocarbon groups, R 7 and R 8 independently include aromatic groups, aliphatic groups, aromatic groups and Combination of, or aliphatic group and A combination of R R is a moiety independently selected from the group consisting of a substituted or unsubstituted aromatic group, a heterocyclic aromatic group, and an aliphatic group, 10 An aromatic group or an aliphatic group is included, and n is a positive integer from 1 to 500.

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