A diamine monomer, polyimide and preparation method and application thereof

Abstract

This invention provides a diamine monomer based on magnolol. It also provides a method for preparing this diamine monomer and its applications. Furthermore, this invention provides a polyimide prepared from this diamine monomer, as well as a method for preparing the polyimide and its applications. Compared to diamine monomers derived from fossil fuels, the diamine monomer of this invention has a lower carbon footprint, contributing to a more sustainable chemical industry. Furthermore, the polyimide obtained by polymerizing this diamine monomer with aromatic diamine monomers and aromatic dianhydride monomers exhibits good solubility in conventional solvents, meeting the process requirements of solution processing. Moreover, the polyimide of this invention contains allyl groups, possessing photocrosslinking properties, and can be applied in fields such as optical data storage devices, photoresists, and photosensitive optical materials, expanding the application range of polyimides.

Description

Technical Field

[0001] This invention relates to the field of polymer compound technology, and in particular to a diamine monomer, a polyimide, and their preparation methods and applications. Background Technology

[0002] Polyimide (PI) refers to a class of polymers containing an imide ring (-CO-NR-CO-) in the main chain. As a special engineering material, it has been widely used in aerospace, microelectronics, nanotechnology, liquid crystal, separation membranes, lasers and other fields.

[0003] Polyimides can be obtained by polymerizing dianhydride monomers and diamine monomers. Commonly used diamine monomers include 4,4'-diaminodiphenyl ether and p-phenylenediamine. These diamine monomers are mostly produced from fossil fuels, which is environmentally unfriendly. In addition, polyimides produced from these traditional diamine monomers cannot be used in fields such as optical data storage devices, photoresists, and photosensitive optical materials, thus limiting their application scope. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a diamine monomer, a polyimide, a method for preparing the same, and its application.

[0005] In a first aspect, the present invention provides a diamine monomer, wherein the general structural formula of the diamine monomer is:

[0006]

[0007] Wherein, R1 is selected from either an ester group or an ether bond; Ar1 ​​is selected from any of the following structures:

[0008]

[0009] In the formula, R1, R2, R3, and R4 are the same or different from each other, and each is selected independently from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or tert-butyl.

[0010] Ar2 is selected from any of the following structures:

[0011]

[0012] In the formula, R5, R6, R7, and R8 are the same as each other or not used, and each is selected independently from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or tert-butyl.

[0013] Secondly, the present invention provides a method for preparing the aforementioned diamine monomer, comprising the following steps:

[0014] (1) Honokiol was reacted with bromobenzoyl chloride containing R1, R2, R3 and R4 at low temperature in an aprotic solvent and alkaline environment to obtain an allyl brominated compound.

[0015] (2) The diamine monomer is obtained by reacting the brominated compound with aminophenylboronic acid or phenylboronic ester containing R5, R6, R7 and R8 via a Suzuki reaction.

[0016] Thirdly, the present invention provides a method for preparing the aforementioned diamine monomer, comprising the following steps:

[0017] (1) Magnolol was reacted with bromonitrobenzene containing R1, R2, R3 and R4 in an aprotic highly polar solvent and an alkaline environment to obtain a dinitro compound containing allyl groups.

[0018] (2) The dinitro compound is reacted with aminophenylboronic acid or phenylboronic ester containing R5, R6, R7 and R8 via Suzuki The diamine monomer was obtained by the Miyaura coupling reaction.

[0019] Fourthly, the present invention provides the application of the aforementioned diamine monomer in the preparation of polyimides, polyamide-imides, or polyamides.

[0020] Fifthly, the present invention provides a polyimide, wherein the general structural formula of the polyimide is:

[0021]

[0022] In the formula, n and m represent the degree of polymerization, n is an integer from 1 to 150, m is an integer from 1 to 150, Ar is the aromatic unit fragment in the diamine monomer, X is a tetravalent aromatic hydrocarbon group, and Ar1 is a residue of the diamine.

[0023] In one embodiment, X is preferably any of the following:

[0024] .

[0025] In one embodiment, the Ar1 is preferably any of the following:

[0026] .

[0027] In a sixth aspect, the present invention provides a method for preparing the aforementioned polyimide, comprising mixing the aforementioned diamine monomer, aromatic diamine monomer, aromatic dianhydride monomer and a third organic solvent, and performing a copolymerization reaction to obtain polyamic acid; wherein the aromatic diamine monomer is p-phenylenediamine, m-phenylenediamine or a flexible aromatic diamine;

[0028] The polyamic acid, dehydrating agent, and third catalyst are mixed and subjected to a chemical imidization reaction to obtain polyimide.

[0029] In one embodiment, the flexible aromatic diamine is selected from 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diaminodiphenyl sulfone, 4,4'-bis(3-aminophenoxy)benzophenone, 3,3'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfide, 4,4-diaminodiphenyl sulfide, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4-diamino-3,3-difluorobiphenyl, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylmethane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 1,2-bis(4-aminophenoxy)ethane, 4,4'-bis(3-aminophenoxy)diphenyl sulfone.

[0030] In a seventh aspect, the present invention provides an application of the aforementioned polyimide in the preparation of photosensitive polyimide photoresist.

[0031] Compared to existing technologies, this invention utilizes the inherent biphenyl-bisphenol structure of magnolol to synthesize a diamine monomer from magnolol. Compared to diamine monomers derived from fossil fuels, the diamine monomer of this invention has a lower carbon footprint, contributing to a more sustainable chemical industry. Furthermore, the polyimide prepared by this invention from the diamine monomer, aromatic diamine monomer, and aromatic dianhydride monomer exhibits good solubility in conventional solvents, meeting the process requirements of solution processing. Moreover, the polyimide of this invention contains allyl groups, possessing photocrosslinking properties, and can be applied in fields such as optical data storage devices, photoresists, and photosensitive optical materials, thus expanding the application range of polyimides. Attached Figure Description

[0032] Figure 1 The above is a 1H NMR spectrum of the diamine monomer prepared in Example 1 of this invention;

[0033] Figure 2 The infrared spectrum of the polyimide prepared in Example 1 of this invention is shown. Detailed Implementation

[0034] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention.

[0035] Magnolol, a natural and safe product extracted from the bark of the magnolia tree, is widely recognized as an excellent functionalized bio-based compound. This invention utilizes the inherent biphenyl-bisphenol structure of magnool to synthesize a diamine monomer from it. Compared to diamine monomers derived from fossil fuels, the diamine monomer of this invention has a lower carbon footprint, contributing to a more sustainable chemical industry. Furthermore, the polyimide prepared by this invention from the diamine monomer, aromatic diamine monomer, and aromatic dianhydride monomer exhibits good solubility in common solvents, meeting the process requirements of solution processing. Moreover, the polyimide of this invention contains allyl groups, possessing photocrosslinking properties, and can be applied in fields such as optical data storage devices, photoresists, and photosensitive optical materials, thus expanding the application range of polyimides.

[0036] Specifically, this invention discloses a diamine monomer with the following general molecular formula:

[0037]

[0038] Wherein, R1 is selected from either an ester group or an ether bond; Ar1 ​​is selected from any of the following structures:

[0039]

[0040] In the formula, R1, R2, R3, and R4 are the same or different from each other, and each is selected independently from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or tert-butyl.

[0041] Ar2 is selected from any of the following structures:

[0042]

[0043] In the formula, R5, R6, R7, and R8 are the same as each other or not used, and each is selected independently from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or tert-butyl.

[0044] This invention also provides a method for preparing a diamine monomer, comprising the following steps:

[0045] (1) Honokiol was reacted with bromobenzoyl chloride containing R1, R2, R3 and R4 at low temperature in an aprotic solvent and alkaline environment to obtain an allyl brominated compound.

[0046] (2) The diamine monomer is obtained by reacting the brominated compound with aminophenylboronic acid or phenylboronic ester containing R5, R6, R7 and R8 via a Suzuki reaction.

[0047] Preferably, in step (1), the aprotic solvent is N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 1,4-dioxane, acetone, acetonitrile, toluene, chloroform, dichloromethane, or tetrahydrofuran. More preferably, in step (1), the aprotic solvent is dichloromethane or tetrahydrofuran.

[0048] Preferably, in step (1), the alkaline environment is a triethylamine or pyridine environment.

[0049] Preferably, in step (1), the low-temperature reaction temperature is -15-10 ℃, and more preferably -5-5 ℃.

[0050] In one embodiment, the present invention also provides a method for preparing a diamine monomer, comprising the following steps:

[0051] (1) Magnolol was reacted with bromonitrobenzene containing R1, R2, R3 and R4 in an aprotic highly polar solvent and an alkaline environment to obtain a dinitro compound containing allyl groups.

[0052] (2) The dinitro compound is reacted with aminophenylboronic acid or phenylboronic ester containing R5, R6, R7 and R8 via Suzuki The diamine monomer was obtained by the Miyaura coupling reaction.

[0053] Preferably, in step (1), the aprotic high polar solvent is N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, or sulfolane.

[0054] Preferably, in step (1), the alkaline environment is a potassium carbonate or sodium carbonate environment.

[0055] Furthermore, the present invention also provides a polyimide with the following general molecular formula:

[0056]

[0057] In the formula, n and m represent the degree of polymerization, where n is an integer from 1 to 150, m is an integer from 1 to 150, Ar is the aromatic unit fragment in the diamine monomer, X is a tetravalent aromatic hydrocarbon group, and Ar1 is a residue of the diamine. Preferably, the structure of X is any one of the following:

[0058] .

[0059] Ar1 preferably has any of the following:

[0060] .

[0061] This invention also provides a method for preparing polyimide, comprising the following steps:

[0062] The diamine monomer, aromatic diamine monomer, aromatic dianhydride monomer, and third organic solvent described in claim 1 are mixed and copolymerized to obtain polyamic acid; wherein the aromatic diamine monomer is p-phenylenediamine, m-phenylenediamine, or a flexible aromatic diamine.

[0063] The polyamic acid, dehydrating agent, and third catalyst are mixed and subjected to a chemical imidization reaction to obtain polyimide.

[0064] Among them, flexible aromatic diamines refer to aromatic diamines containing flexible groups. Preferably, the flexible aromatic diamine is selected from 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diaminodiphenyl sulfone, 4,4'-bis(3-aminophenoxy)benzophenone, 3,3'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfide, 4,4-diaminodiphenyl sulfide, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4-diamino-3,3-difluorobiphenyl, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylmethane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 1,2-bis(4-aminophenoxy)ethane, 4,4'-bis(3-aminophenoxy)diphenyl sulfone.

[0065] Preferably, the aromatic dianhydride monomer is selected from 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 4,4'-oxophthalic anhydride, 2,3,3',4'-diphenyl ether tetracarboxylic acid dianhydride, 3,3,4,4-diphenyl sulfone tetracarboxylic acid dianhydride, 4,4'-(hexafluoroisopropene)phthalic anhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 4,4'-terephthalodioxyphthalic anhydride, bisphenol A type diether dianhydride, and ethylene glycol bis(triphenylene)dihydride.

[0066] Preferably, the third organic solvent is selected from one or more of the following solvents: N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 1,4-dioxane, acetone, acetonitrile, toluene, chloroform, hexamethylphosphoric triamine, and tetrahydrofuran.

[0067] Preferably, the dehydrating agent is one or a mixture of acetic anhydride and trifluoroacetic anhydride.

[0068] Preferably, the third catalyst is one or a mixture of two or more of pyridine, triethylamine, quinoline, isoquinoline and imidazole.

[0069] Preferably, the specific steps of the chemical imidization are as follows: adding a dehydrating agent and a catalyst to a viscous polyamic acid solution, wherein the dehydrating agent is acetic anhydride and the catalyst is pyridine, stirring at room temperature for 24-40 h, and then pouring it into a large amount of ethanol to obtain fibrous polyimide, which is washed three times with ethanol and then dried for later use.

[0070] To further understand the present invention, the preparation methods of diamine monomers and polyimides provided by the present invention will be described in detail below with reference to the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0071] Example 1

[0072] 4-Bromobenzoyl chloride (24.14 g, 105 mmol) was dissolved in 120 mL of tetrahydrofuran, and then a tetrahydrofuran solution (60 mL) of magnolol (13.32 g, 50 mmol) and triethylamine (20.9 mL, 150 mmol) was added dropwise. After stirring at room temperature for 12 h, the solution was extracted with dilute hydrochloric acid and deionized water until neutralized to give an allyl-containing brominated compound. The allyl-containing brominated compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform- d ) δ : 7.78 (dt, J = 8.8, 2.3 Hz, 2H), 7.54 (dt, J = 8.9, 2.3 Hz, 2H), 7.18 (d, J= 1.9 Hz, 3H), 5.82 (ddt, J = 17.6, 9.5, 6.7 Hz, 1H), 4.99 (dq, J = 13.1, 1.8Hz, 2H), 3.33 (dt, J = 6.6, 1.7 Hz, 2H). 13C NMR (151 MHz, Chloroform-d) δ :164.44, 146.52, 137.92, 136.93, 131.91, 131.65, 131.33, 130.27, 129.33, 128.76, 128.47, 122.54, 116.31, 39.61.

[0073] Under argon atmosphere, the above-mentioned allyl-containing brominated compound (9.48 g, 15 mmol) and tetraphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran. After stirring for 10 minutes, 3 M potassium phosphate aqueous solution (60 mL) and (4-aminophenyl) hydrochloride borate (7.80 g, 45 mmol) were added, and the mixture was stirred further at 75 °C for 24 h. After cooling to room temperature, the mixture was concentrated and purified to obtain the diamine monomer, named DDBA. DDBA was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, DMSO- d 6) δ : 7.89 (d, J = 8.3 Hz, 2H), 7.69 (d, J = 8.4 Hz, 2H), 7.48 (d, J =8.4 Hz, 2H), 7.32 – 7.13 (m, 3H), 6.66 (d, J = 8.5 Hz, 2H), 5.89 – 5.73 (m,1H), 5.45 (s, 2H), 5.09 – 4.85 (m, 2H), 3.34 (s, 4H). 13 C NMR (151 MHz, DMSO-d6) δ 164.32, 149.63, 146.21, 145.79, 137.29, 137.19, 130.76, 130.23, 129.83, 129.07, 127.71, 125.42, 125.25, 125.02, 123.00, 116.05, 114.14, 38.65. HR-MS (ESI, m / z). The 1H NMR spectrum is shown below. Figure 1 As shown.

[0074]

[0075] Diamine monomers DDBA (7.61 mmol) and 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether (6FODA, 7.61 mmol) were dissolved in anhydrous N-methylpyrrolidone (NMP) solution (57 mL), followed by the addition of 4,4-hexafluoroisopropylphthalic anhydride (6FDA, 14.27 mmol). The reaction was carried out under nitrogen protection at room temperature to obtain a polyamic acid solution. Subsequently, acetic anhydride (4.02 mL) and pyridine (1.73 mL) were added for chemical imidization. After stirring the solution for 24 hours, it was precipitated in a large amount of ethanol, washed three times with ethanol, and dried to obtain a polyimide powder with the structure shown in Formula 1. The obtained polyimide was designated PI-1, with a number-average molecular weight of 28,000 g / mol. The infrared spectrum is shown below. Figure 2 As shown.

[0076] Formula 1

[0077] Example 2

[0078] 2-Trifluoromethyl-4-bromobenzoyl chloride (30.18 g, 105 mmol) was dissolved in 150 mL of tetrahydrofuran, and then a tetrahydrofuran solution (60 mL) of magnolol (13.32 g, 50 mmol) and triethylamine (20.9 mL, 150 mmol) was added dropwise. After stirring at room temperature for 12 h, the solution was extracted with dilute hydrochloric acid and deionized water until neutralized to give an allyl-containing brominated compound. The allyl-containing brominated compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 8.02 (d, J = 8.3 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.64 (dd, J =8.3, 2.0 Hz, 1H), 7.31 – 7.24 (m, 2H), 7.21 (ddt, J = 8.8, 2.0, 1.0 Hz, 1H),5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 3.33 (dt, J = 7.5, 1.0Hz, 2H). 13 C NMR (151 MHz, Chloroform- d) δ : 166.76, 148.53, 137.67, 134.25, 133.08, 132.71, 132.25, 130.96, 130.59, 130.29, 129.03, 126.28, 125.44, 123.14, 119.01, 115.61, 39.44.

[0079] Under argon atmosphere, the above-mentioned allyl-containing brominated compound (11.53 g, 15 mmol) and tetraphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran. After stirring for 10 min, 3 M potassium phosphate aqueous solution (60 mL) and (4-aminophenyl) hydrochloride borate (7.80 g, 45 mmol) were added, and the mixture was stirred further at 75 °C for 24 h. After cooling to room temperature, the mixture was concentrated and purified to obtain the diamine monomer, named F-DDBA. F-DDBA was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400MHz, Chloroform- d ) δ 8.07 (d, J = 7.5 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.64 –7.57 (m, 2H), 7.57 (dd, J = 7.6, 2.1 Hz, 1H), 7.31 – 7.24 (m, 2H), 7.21 (ddt, J =8.8, 2.0, 1.0 Hz, 1H), 6.72 – 6.66 (m, 2H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 4.21 (d, J = 5.7 Hz, 1H), 4.13 (d, J = 5.7 Hz, 1H), 3.33(dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform- d ) δ: 167.71, 148.86, 148.53, 143.97, 137.67, 134.83, 134.25, 131.80, 131.36, 130.59, 130.29, 129.03, 127.73, 126.72, 125.88, 125.82, 123.13, 119.01, 115.61, 115.35, 39.44.

[0080]

[0081] The preparation method of polyimide in this embodiment is basically the same as that in Example 1, except that DDBA is replaced with F-DDBA. This embodiment yields polyimide powder with the structure shown in Formula 2, denoted as PI-2, with a number-average molecular weight of 32000 g / mol.

[0082] Formula 2

[0083] Example 3

[0084] 2-Trifluoromethyl-4-bromobenzoyl chloride (30.18 g, 105 mmol) was dissolved in 150 mL of tetrahydrofuran, and then a tetrahydrofuran solution (60 mL) of magnolol (13.32 g, 50 mmol) and triethylamine (20.9 mL, 150 mmol) was added dropwise. After stirring at room temperature for 12 h, the solution was extracted with dilute hydrochloric acid and deionized water until neutralized to give an allyl-containing brominated compound. The allyl-containing brominated compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform- d ) δ 8.02 (d, J = 8.3 Hz, 1H), 7.93 (d, J = 2.0 Hz, 1H), 7.64 (dd, J =8.3, 2.0 Hz, 1H), 7.31 – 7.24 (m, 2H), 7.21 (ddt, J = 8.8, 2.0, 1.0 Hz, 1H),5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 3.33 (dt, J = 7.5, 1.0Hz, 2H). 13C NMR (151 MHz, Chloroform- d ) δ : 166.76, 148.53, 137.67, 134.25, 133.08, 132.71, 132.25, 130.96, 130.59, 130.29, 129.03, 126.28, 125.44, 123.14, 119.01, 115.61, 39.44.

[0085] Under argon atmosphere, the above-mentioned allyl-containing brominated compound (11.53 g, 15 mmol) and tetraphenylphosphine palladium were dissolved in 250 mL of tetrahydrofuran. After stirring for 10 min, 60 mL of 3 M potassium phosphate aqueous solution and (3-amino-5-methylphenyl)boric acid (6.80 g, 45 mmol) were added, and the mixture was stirred further at 75 °C for 24 h. After cooling to room temperature, the mixture was concentrated and purified to obtain the diamine monomer, named F-DDBA-CH3. F-DDBA-CH3 was characterized by nuclear magnetic resonance, and the results were as follows: 1 HNMR (400 MHz, Chloroform-d) δ:7.99 (d, J = 7.5 Hz, 1H), 7.92 (d, J = 2.1 Hz,1H), 7.46 (dd, J = 7.5, 2.1 Hz, 1H), 7.31 – 7.24 (m, 3H), 7.21 (ddt, J = 8.8,2.0, 1.0 Hz, 1H), 6.96 (t, J = 2.1 Hz, 1H), 6.58 – 6.53 (m, 1H), 6.01 – 5.87(m, 1H), 5.10 (dd, J = 13.3, 3.6 Hz, 2H), 4.38 (s, 2H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform-d) δ : 167.71, 148.53, 147.44, 144.09, 141.21, 140.45, 137.67, 134.25, 131.83, 131.33, 130.59, 130.29, 129.03, 125.82, 124.78, 124.43, 123.13, 120.90, 119.01, 115.69, 115.61, 110.85, 39.44, 21.13.

[0086]

[0087] The preparation method of polyimide in this embodiment is basically the same as that in Example 1, except that DDBA is replaced with F-DDBA-CH3. This embodiment yields polyimide powder with the structure shown in Formula 3, denoted as PI-3, with a number-average molecular weight of 30,000 g / mol.

[0088] Formula 3

[0089] Example 4

[0090] Magnolol (6.00 g, 22.5 mmol), p-bromonitrobenzene (13.64 g, 67.5 mmol), and potassium carbonate (12.44 g, 90.0 mmol) were dissolved in 100 mL of anhydrous N,N-dimethylacetamide and reacted under nitrogen protection. After the reaction was complete, the solid was collected by filtration and recrystallized to obtain a dinitro compound. The dinitro compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform- d ) δ : 8.28 – 8.22 (m, 2H), 7.29 (dt, J= 2.0, 1.1 Hz, 1H), 7.25 – 7.19 (m, 1H), 7.19 – 7.13 (m, 2H), 7.01 (d, J =8.6 Hz, 1H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.7 Hz, 2H), 3.33(dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform- d ) δ : 162.43, 154.71, 142.77, 137.67, 134.27, 130.13, 129.67, 128.70, 125.57, 118.42, 117.02, 115.61, 39.44.

[0091] Under a nitrogen atmosphere, the above-mentioned dinitro compound (2.00 g, 3.9 mmol), (4-aminophenyl)borate hydrochloride (2.03 g, 11.7 mmol), palladium acetate (catalytic amount), BrettPhos ligand (catalytic amount), and potassium phosphate (6.62 g, 31.2 mmol) were dissolved in 50 mL of 1,4-dioxane and stirred further at 130 °C for 24 h. After cooling to room temperature, the solution was concentrated and purified to obtain the diamine monomer, named DBA. DBA was characterized by nuclear magnetic resonance, and the results are as follows: 1 H NMR (400MHz, Chloroform- d ) δ :7.63 – 7.57 (m, 2H), 7.51 – 7.45 (m, 2H), 7.29 (dt, J =2.0, 1.0 Hz, 1H), 7.25 – 7.17 (m, 1H), 7.20 (s, 1H), 7.18 (d, J = 1.6 Hz, 1H), 7.00 (d, J = 8.5 Hz, 1H), 6.72 – 6.66 (m, 2H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 4.21 (d, J = 5.7 Hz, 1H), 4.13 (d, J = 5.7 Hz, 1H), 3.33(dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform- d ) δ : 158.26, 154.53, 148.86, 137.67, 134.27, 132.93, 130.13, 130.05, 129.67, 129.28, 128.87, 128.70, 119.76, 117.02, 116.49, 115.61, 39.44.

[0092]

[0093] The preparation method of polyimide in this embodiment is basically the same as that in Example 1, except that DDBA is replaced with DBA. This embodiment yields polyimide powder with the structure shown in Formula 4, denoted as PI-4, with a number-average molecular weight of 27500 g / mol.

[0094] Formula 4

[0095] Example 5

[0096] Magnolol (6.00 g, 22.5 mmol), p-bromonitrobenzene (13.64 g, 67.5 mmol), and potassium carbonate (12.44 g, 90.0 mmol) were dissolved in 100 mL of anhydrous N,N-dimethylacetamide and reacted under nitrogen protection. After the reaction was complete, the solid was collected by filtration and recrystallized to obtain a dinitro compound. The dinitro compound was characterized by nuclear magnetic resonance, and the results were as follows: 1 H NMR (400 MHz, Chloroform- d ) δ : 8.28 – 8.22 (m, 2H), 7.29 (dt, J= 2.0, 1.1 Hz, 1H), 7.25 – 7.19 (m, 1H), 7.19 – 7.13 (m, 2H), 7.01 (d, J =8.6 Hz, 1H), 5.94 (tt, J = 9.8, 7.5 Hz, 1H), 5.10 (d, J = 9.7 Hz, 2H), 3.33(dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform- d ) δ : 162.43, 154.71, 142.77, 137.67, 134.27, 130.13, 129.67, 128.70, 125.57, 118.42, 117.02, 115.61, 39.44.

[0097] Under a nitrogen atmosphere, the above-mentioned dinitro compound (2.00 g, 3.9 mmol), (3-amino-5-methylphenyl)boronic acid (1.77 g, 11.7 mmol), palladium acetate (catalytic amount), BrettPhos ligand (catalytic amount), and potassium phosphate (6.62 g, 31.2 mmol) were dissolved in 50 mL of 1,4-dioxane and stirred further at 130 °C for 24 h. After cooling to room temperature, the solution was concentrated and purified to obtain the diamine monomer, named DBA-CH3. DBA-CH3 was characterized by nuclear magnetic resonance, and the results were as follows: 1 HNMR (400 MHz, Chloroform- d ) δ :7.63 – 7.57 (m, 2H), 7.51 – 7.45 (m, 2H), 7.29(dt, J = 2.0, 1.0 Hz, 1H), 7.25 – 7.17 (m, 1H), 7.20 (s, 1H), 7.18 (d, J = 1.6Hz, 1H), 7.00 (d, J = 8.5 Hz, 1H), 6.72 – 6.66 (m, 2H), 5.94 (tt, J = 9.8, 7.5Hz, 1H), 5.10 (d, J = 9.6 Hz, 2H), 4.21 (d, J = 5.7 Hz, 1H), 4.13 (d, J = 5.7 Hz, 1H), 3.33 (dt, J = 7.5, 1.0 Hz, 2H). 13 C NMR (151 MHz, Chloroform- d ) δ : 158.26,154.53, 148.86, 137.67, 134.27, 132.93, 130.13, 130.05, 129.67, 129.28,128.87, 128.70, 119.76, 117.02, 116.49, 115.61, 39.44.

[0098]

[0099] The preparation method of polyimide in this embodiment is basically the same as that in Example 1, except that DDBA is replaced with DBA-CH3. This embodiment yields polyimide powder with the structure shown in Formula 5, denoted as PI-5, with a number-average molecular weight of 33000 g / mol.

[0100] Formula 5

[0101] Comparative Example 1

[0102] 4,4'-Diaminodiphenyl ether (ODA, 5 mmol) was dissolved in anhydrous N-methylpyrrolidone (NMP) solution (15 mL), and then 4,4-hexafluoroisopropylphthalic anhydride (6FDA, 4.69 mmol) was added. The reaction was carried out under nitrogen protection and at room temperature to obtain a polyamic acid solution. Subsequently, acetic anhydride (1.32 mL) and pyridine (0.57 mL) were added to carry out a chemical imidization reaction. After stirring the solution for 24 hours, it was precipitated in a large amount of ethanol, washed three times with ethanol, and dried to obtain a polyimide powder with the structure shown in Formula 6, denoted as PI-6. The number average molecular weight was 29800 g / mol.

[0103]

[0104] Formula 6

[0105] Comparative Example 2

[0106] The preparation method of this comparative example is basically the same as that of comparative example 1, except that ODA is replaced with 4,4'-diamino-2,2'-dimethylbiphenyl (M-tolidine) to prepare a polyimide with the structure of formula 7, denoted as PI-7. The number average molecular weight is 31000 g / mol.

[0107]

[0108] Formula 7

[0109] The solubility properties of the polyimides prepared in Examples 1-5 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0110] Table 1. Solubility data of polyimide

[0111]

[0112] Where ++ indicates soluble at room temperature, +- indicates partially soluble at room temperature, and -- indicates insoluble at room temperature; NMP is N-methylpyrrolidone, DMF is N,N-dimethylformamide, DMAc is N,N-dimethylacetamide, THF is tetrahydrofuran, DCM is dichloromethane, EA is ethyl acetate, and PGEMA is propylene glycol methyl ether acetate.

[0113] As shown in Table 1, compared with Comparative Examples 1 and 2, the polyimide prepared by this invention is soluble in most high-boiling-point polar solvents (NMP, DMF, DMAc) at room temperature, as well as in low-boiling-point solvents (DCM, THF) and non-toxic solvents (EA and PGEMA). Therefore, the polyimide resin prepared by this invention has good solubility in conventional solvents, which can meet the process requirements of solution processing.

[0114] Furthermore, compared to Comparative Examples 1 and 2, the polyimide prepared by this invention contains allyl groups. Since the allyl groups are photocrosslinking groups, the polyimide prepared by this invention possesses photocrosslinking properties, thereby enabling its application in fields such as optical data storage devices, photoresists, and photosensitive optical materials, thus expanding the application range of polyimides.

[0115] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A diamine monomer, characterized in that, The general structural formula of the diamine monomer is: Wherein, R1 is selected from either an ester group or an ether bond; Ar1 ​​is selected from any of the following structures: In the formula, R1, R2, R3, and R4 are the same or different from each other, and each is selected independently from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or tert-butyl. Ar2 is selected from any of the following structures: In the formula, R5, R6, R7, and R8 are the same as each other or not used, and each is selected independently from hydrogen, fluorine, methyl, ethyl, trifluoromethyl, or tert-butyl.

2. A method for preparing the diamine monomer as described in claim 1, comprising the following steps: (1) Honokiol was reacted with bromobenzoyl chloride containing R1, R2, R3 and R4 at low temperature in an aprotic solvent and alkaline environment to obtain an allyl brominated compound. (2) The diamine monomer is obtained by reacting the brominated compound with aminophenylboronic acid or phenylboronic ester containing R5, R6, R7 and R8 via a Suzuki reaction.

3. A method for preparing the diamine monomer as described in claim 1, comprising the following steps: (1) Magnolol was reacted with bromonitrobenzene containing R1, R2, R3 and R4 in an aprotic highly polar solvent and an alkaline environment to obtain a dinitro compound containing allyl groups. (2) The dinitro compound is reacted with aminophenylboronic acid or phenylboronic ester containing R5, R6, R7 and R8 via Suzuki The diamine monomer was obtained by the Miyaura coupling reaction.

4. The use of the diamine monomer as described in claim 1 in the preparation of polyimides, polyamide-imides, or polyamides.

5. A polyimide, characterized in that, The general structural formula of the polyimide is: In the formula, n and m represent the degree of polymerization, n is an integer from 1 to 150, m is an integer from 1 to 150, and Ar is the aromatic unit fragment in the diamine monomer of claim 1; X is selected from any of the following: ； Ar1 is selected from any of the following: 。 6. A method for preparing the polyimide according to claim 5, comprising the following steps: The diamine monomer, aromatic diamine monomer, aromatic dianhydride monomer, and third organic solvent described in claim 1 are mixed and copolymerized to obtain polyamic acid; wherein the aromatic diamine monomer is p-phenylenediamine, m-phenylenediamine, or a flexible aromatic diamine. The polyamic acid, dehydrating agent, and third catalyst are mixed and subjected to a chemical imidization reaction to obtain polyimide; The flexible aromatic diamine is selected from 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 1,3-bis(4'-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminophenyl ether, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diaminodiphenyl sulfone, 4,4'-bis(3-aminophenoxy)benzophenone, 3,3'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfide, 4,4-diaminodiphenyl sulfide, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4-Diamino-3,3-difluorobiphenyl, 9,9-bis(4-aminophenyl)fluorene, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylmethane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 1,2-bis(4-aminophenoxy)ethane, 4,4'-bis(3-aminophenoxy)diphenyl sulfone.

7. The application of the polyimide as described in claim 5 in the preparation of photosensitive polyimide photoresist.

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