A fully bio-based aryl diamine polyimide film and a method of making the same

Abstract

The application discloses a kind of full biological base aryl diamine polyimide film and preparation method thereof, the preparation method includes the following steps: aryl diamine compound IV is condensed with diacid anhydride compound to obtain the solution containing polyamic acid compound V.The product of the application can be used to replace traditional diamine and acid anhydride polymerization into polyimide film, improve the thermal performance and mechanical properties of polyimide film, while also reduce the hygroscopic expansion coefficient.

Description

Technical Field

[0001] This invention belongs to the field of bio-based polymer materials, specifically relating to a fully bio-based aryl diamine polyimide film and its preparation method. Background Technology

[0002] Lignin is a renewable carbon source with great potential due to its aromatic structure, serving as a renewable resource for directional compounds. However, the effective utilization of lignin has always faced challenges. The decomposition of lignin is often difficult to achieve, and the decomposition products are difficult to further utilize. Therefore, incineration is commonly used to convert it into heat and electricity, failing to fully realize its potential.

[0003] To address this issue, innovative new methods are needed to achieve the sustainable decomposition and resource recovery of lignin. This challenge may require innovations in biotechnology, catalysts, and engineering techniques. These innovations could efficiently convert lignin into more valuable compounds, such as biofuels and high-value-added chemicals.

[0004] In the field of biotechnology, methods for microbial degradation of lignin can be explored to break it down into useful metabolites. This requires finding microorganisms with highly efficient lignin-degrading enzymes or achieving this goal through genetic engineering of microorganisms.

[0005] Catalyst innovation is also a key factor. Novel catalysts can promote the cracking and conversion of lignin under mild conditions, avoiding the incineration process under high temperature and high pressure. This will help reduce energy consumption and environmental impact.

[0006] Advances in engineering technology can also improve the availability of lignin resources, including designing more efficient reactors and processes, as well as improving waste treatment methods to minimize resource waste.

[0007] Vanillin possesses multiple reactive groups in its chemical structure, including phenolic hydroxyl groups, aldehyde groups, and its rigid ring structure. This unique chemical structure allows vanillin to undergo various chemical reactions, modifications, and polymerizations to prepare vanillin-based products with different mechanical and thermal properties. Therefore, vanillin is widely recognized as an excellent bio-based platform compound. Based on vanillin, a series of vanillin-based bio-polymers have been developed, such as polybenzoxazine, phenolic resins, polyurethanes, and epoxy resins. Vanillin can be introduced into other polymers through hydrogen bonding or chemical reactions to enhance the overall mechanical and thermal properties of the polymer. In addition, vanillin is widely used in the synthesis of surfactants, photosensitizers, and antibacterial components, expanding its application areas.

[0008] Aromatic polyamides possess excellent mechanical properties and thermal stability, making them suitable as high-performance materials for advanced technologies. They are typically synthesized from aromatic diamines and aromatic dicarboxylic acids. Currently available commercially available aromatic polyamides are used as advantageous alternatives to metals or ceramics, and there is a growing demand for them as novel materials in new technological applications.

[0009] However, the application of aromatic polyamides is often hindered by their manufacturing problems. For example, the high crystallinity and rigidity of the polymer backbone lead to poor solubility, high softening or melting temperatures, which makes the processing of aromatic polyamides difficult.

[0010] To overcome these problems, extensive research has been conducted, resulting in the synthesis of structurally modified aromatic polyamides that improve solubility and processability while maintaining high thermal stability. Methods include introducing flexible chains into the main chain, synthesizing non-coplanar units using oriented monomers, introducing imine groups, and synthesizing polyamide-imines (PAIs). These modification methods work by disrupting chain symmetry and regularity, as well as breaking hydrogen bonds, generally leading to better solubility and processability.

[0011] Furthermore, polymers with photosensitive groups, such as cinnamates, chalcones, coumarins, benzoacetone, and their derivatives, have attracted widespread attention, whether introduced into the main chain or side chains. These materials have potential applications in many fields, including optical data storage devices, photoresists, and photolithography components. Therefore, the design and synthesis of polymers highly sensitive to light processing remains a research hotspot. By incorporating appropriate chemical structures into the polymer backbone, the properties of various materials can be improved, providing broader possibilities for applications in the optical and optoelectronic fields.

[0012] Therefore, the present invention provides a fully bio-based aryl diamine polyimide film and its preparation method. Summary of the Invention

[0013] Purpose of the invention: The technical problem to be solved by the present invention is to provide a fully bio-based aryl diamine polyimide, which addresses the shortcomings of the prior art.

[0014] Another technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned fully bio-based aryl diamine polyimide.

[0015] Another technical problem that the present invention needs to solve is to provide a polyimide film.

[0016] Invention Concept: This invention uses lignin oxidation degradation products and ketone compounds from sugar platform fermentation as starting materials to synthesize a fully bio-based aryl diamine polyimide, avoiding the dependence on fossil resources caused by traditional polyimide production. This polyimide introduces a double-bond structure, which provides flexible segments, helping to improve the flexibility and processability of the polyimide material, and also reduces intermolecular hydrogen bonds, lowering the material's water absorption. An aromatic ring structure is also introduced; the strong rigidity and large steric hindrance of the aromatic ring structure increase the material's thermal stability. Finally, a ketone group is introduced, which is a photosensitive group. This photosensitive group in the polyimide can achieve light response and control, thereby expanding the application fields of these materials, including optics, electronics, sensing, and micro / nano manufacturing.

[0017] To solve the first technical problem mentioned above, the present invention discloses a compound as shown in Formula I, namely, a fully bio-based aryl diamine polyimide;

[0018]

[0019] in,

[0020] R1 and R3 are each independently selected from -H or -OCH3;

[0021] R2 is selected from -H, -CH3, -CH2CH3, -CH2-CH2-, or -CH2-CH2-CH2-; in some embodiments, R2 is selected from -H, -CH3, -CH2-CH2-, or -CH2-CH2-CH2-; in some embodiments, R2 is selected from -H, -CH3, or -CH2-CH2-.

[0022] Ar is selected from tetravalent organic groups having C6-C20 aromaticity; in some embodiments, Ar is selected from any one of the following structural formulas Ar1 to Ar3;

[0023]

[0024] n is selected from 2 to 30.

[0025] In some specific embodiments, the compound represented by Formula I is any one of Formula I1-Formula I12, wherein n is selected from 2 to 30;

[0026]

[0027]

[0028] To address the second technical problem mentioned above, this invention discloses a method for preparing the compound represented by Formula I.

[0029] The preparation method includes the following steps:

[0030] S1: The lignin oxidative depolymerization monomer compound II and the glycoplatform bio-based ketone compound VI were subjected to aldol condensation to obtain the coupled bisphenol compound III;

[0031] S2: The coupling of bisphenol compound III is reacted with phenolic hydroxyl amination under metal-free or metal-catalyzed conditions to give aryl diamine compound IV;

[0032] S3: A condensation reaction of aryl diamine compound IV with dianhydride compounds in a polar aprotic solvent yields a solution containing polyamic acid compound V;

[0033] S4: Polyamic acid compound V undergoes an imidization reaction at high temperature to obtain the bio-based diamine polyimide shown in Formula I.

[0034]

[0035] in,

[0036] R1 and R3 are each independently selected from -H or -OCH3;

[0037] R2 is selected from -H, -CH3, -CH2CH3, -CH2-CH2-, or -CH2-CH2-CH2-; in some embodiments, R2 is selected from -H, -CH3, -CH2-CH2-, or -CH2-CH2-CH2-; in some embodiments, R2 is selected from -H, -CH3, or -CH2-CH2-.

[0038] n is selected from 2 to 30.

[0039] In step S3, the dianhydride compounds are 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), and pyromellitic dianhydride (PMDA).

[0040] In step S3, the molar ratio of the aryl diamine compound IV to the dianhydride compound is 1:0.5-2, preferably 1:0.5-1, more preferably 1:0.8-1.2, and even more preferably 1:0.95.

[0041] In step S3, the solvent for the condensation reaction is a polar aprotic solvent; preferably, the polar aprotic solvent includes N-methylpyrrolidone.

[0042] In step S3, the ratio of the amount of aryl diamine compound IV to the solvent is 0.01-0.2 mol / 200 mL.

[0043] In step S3, the condensation reaction temperature is 20-60℃, preferably 20-40℃, and more preferably 30℃; preferably, the condensation reaction time is 4-12h, and more preferably 4-10h.

[0044] In step S3, the condensation reaction must be carried out under nitrogen protection.

[0045] In step S4, the imidization reaction involves drying a solution containing polyamic acid compound V on a hot glass plate at 80-120°C, then peeling it off to obtain a self-supporting film. The self-supporting film is then fixed to a fixture and placed in a hot air dryer for drying at 300-400°C. In some embodiments, the solution containing polyamic acid compound V is dried on a hot glass plate at 100°C, then peeled off to obtain a self-supporting film, then fixed to a fixture and placed in a hot air dryer for drying at 350°C.

[0046] To address the third technical problem mentioned above, this invention discloses a polyimide film comprising any of the compounds described in the first technical problem above, or a compound prepared by the method described in the second technical problem above.

[0047] The polyimide film has a moisture absorption expansion coefficient of less than 6 ppm / RH%.

[0048] The tensile modulus of the polyimide film is 8-11 GPa.

[0049] The tensile strength of the polyimide film is 400-450 MPa.

[0050] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0051] 1. This invention uses lignin oxidation degradation products and ketone compounds from cellulose platform fermentation products as raw materials to synthesize a fully bio-based aryl diamine polyimide through structural design. This polyimide can be used to replace traditional diamines in the preparation of polyimide films, avoiding the dependence on fossil resources caused by the production of traditional diamine compounds.

[0052] 2. The introduction of unique double bonds into the molecular structure of the all-biobased aryldiamine polyimide of this invention significantly improves the flexibility and processability of the polyimide. Simultaneously, the introduction of a ketone group into the polymer backbone enables the polyimide to respond to and be controlled by light. This innovation expands the application areas of these materials, including but not limited to optics, electronics, sensing, and micro / nanofabrication. Therefore, this invention has the potential to advance materials science and engineering in multiple fields. Attached Figure Description

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0054] Figure 1 This is the synthetic route for the all-bio-based aryl diamine polyimide of this invention.

[0055] Figure 2 This is the synthetic route for the all-bio-based aryl diamine polyimide in Example 1.

[0056] Figure 3 The images show the FTIR spectra of BTDA, bio-based diamine, and polyamic acid solutions from Example 1.

[0057] Figure 4 The images show the FTIR spectra of the polyamic acid solution and the polyimide film in Example 1. Detailed Implementation

[0058] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0059] Example 1: Preparation of I11: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-2,6-bis[-(4-amino-3-methoxyphenyl)methyl alkylene]cyclohexanone].

[0060] Under nitrogen protection, 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA, 30.6 g, 0.095 mol) was added three times to a stirred mixed solution of 2,6-bis[-(4-amino-3-methoxyphenyl)methylethylene]cyclohexanone IV11 (36.6 g, 0.1 mol) and N-methylpyrrolidone (200 mL), in a monomer mass ratio of 1 (5.1 g): 2 (10.2 g): 3 (15.3 g). The condensation reaction was carried out at 30 °C and 200 rpm for 8 h to obtain a polyamic acid solution. BTDA, bio-based diamine, and polyamic acid solution were analyzed by ATR-FTIR, and the results are shown below. Figure 3 As shown. BTDA at 1214cm -1 The absorption peak at 3100-3588 cm⁻¹ is a vibrational peak caused by the C=O bond in the acid anhydride group, but this vibrational peak disappears in PAA solution. In bio-based diamine, the peak is at 3100-3588 cm⁻¹. -1 The absorption peak at 2739-3055 cm⁻¹ is an amino vibration peak, which disappears in PAA solution; the absorption peak at 2739-3055 cm⁻¹ in PAA solution is also present. -1 The absorption peak at 1688 cm⁻¹ is a vibrational peak caused by the carboxyl group. -1The absorption peak at that point is a vibrational peak caused by the C=O bond in the amide group, which confirms that bio-based diamine and BTDA have successfully undergone polymerization, forming amide and carboxyl groups.

[0061] 20 mL of the polyamic acid solution obtained above was evenly coated onto a glass plate and dried on a hot plate at 100°C for 1 hour. The self-supporting film was then peeled off and fixed onto a stainless steel clamp. Finally, it was dried in a hot air dryer at 350°C for 2 hours to obtain a 10 μm thick transparent polyimide film. The film was characterized by ATR-FTIR, and the results are as follows: Figure 4 As shown, in this polyimide film, 2739-3055 cm -1 The vibrational peak caused by the carboxyl group was no longer observed at 1710 cm⁻¹. -1 and 1792cm -1 The peak at this point is caused by the CN bond in the imide group, which confirms that the PAA solution successfully underwent a thermal imidization reaction, resulting in the disappearance of the carboxyl group and the formation of an imide group.

[0062] Example 2: Preparation of I10: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-2,6-bis[(4-aminophenyl)methyl alkylene]cyclohexanone].

[0063] I10 was prepared by replacing IV11 with IV10 raw material, following the method in Example 8.

[0064] Example 3: Preparation of I12: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-2,6-bis[(4-amino-3,5-dimethoxyphenyl)methyl alkylene]cyclohexanone].

[0065] I12 was prepared by replacing IV11 with IV12 raw material, following the method of Example 8.

[0066] Example 4: Preparation of I2: poly[3,3'4,4'-benzophenone tetracarboxylic dianhydride-(1,4)-1,5-bis(4-amino-3-methoxyphenyl)pent-1,4-dien-3-one].

[0067] I2 was prepared by replacing IV11 with IV2 raw material, referring to the method in Example 8.

[0068] Example 5: Preparation of I3: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-(1,4)-1,5-bis(4-amino-3,5-dimethoxyphenyl)pent-1,4-dien-3-one].

[0069] I3 was prepared by replacing IV11 with IV3 raw material, referring to the method in Example 8.

[0070] Example 6: Preparation of I4: poly[3,3'4,4'-benzophenone tetracarboxylic dianhydride-(1,4)-1,5-bis(4-aminophenyl)-2,4-dimethylpent-1,4-dien-3-one].

[0071] I4 was prepared by replacing IV11 with IV4 raw material, following the method in Example 8.

[0072] Example 7: Preparation of I5: poly[3,3'4,4'-benzophenone tetracarboxylic dianhydride-(1,4)-1,5-bis(4-amino-3-methoxyphenyl)-2,4-dimethylpent-1,4-dien-3-one].

[0073] I5 was prepared by replacing IV11 with IV5 raw material, following the method of Example 8.

[0074] Example 8: Preparation of I6: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-(1,4)-1,5-bis(4-amino-3,5-dimethoxyphenyl)-2,4-dimethylpent-1,4-dien-3-one].

[0075] I6 was prepared by replacing IV11 with IV6 raw material, following the method in Example 8.

[0076] Example 9: Preparation of I7: poly[3,3'4,4'-benzophenone tetracarboxylic dianhydride-2,5-bis[(4-aminophenyl)methyl methyl]cyclopentan-1-one].

[0077] I7 was prepared by replacing IV11 with IV7 raw material, referring to the method in Example 8.

[0078] Example 10: Preparation of I8: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-2,5-bis[(4-amino-3-methoxyphenyl)methyl methylidene]cyclopentan-1-one].

[0079] I8 was prepared by replacing IV11 with IV8 raw material, following the method of Example 8.

[0080] Example 11: Preparation of I9: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-2,5-bis[(4-amino-3,5-dimethoxyphenyl)methyl methyl alkyl]cyclopentan-1-one].

[0081] Following the method of Example 8, I9 was prepared by replacing IV11 with IV9 raw material.

[0082] Example 12: Preparation of I1: poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-(1,4)-1,5-bis(4-aminophenyl)pentan-1,4-dien-3-one].

[0083] Following the method of Example 8, I1 was prepared by replacing IV11 with the same IV1 raw material.

[0084] Comparative Example 1: Poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-p-phenylenediamine].

[0085] Following the method of Example 8, poly[3,3',4,4'-benzophenone tetracarboxylic acid dianhydride-p-phenylenediamine] was prepared by replacing IⅤ11 with p-phenylenediamine.

[0086] Comparative Example 2: Poly[3,3',4,4'-benzophenone tetracarboxylic dianhydride-metatoluidine].

[0087] Referring to the method of Example 8, poly[3,3'4,4'-benzophenone tetracarboxylic dianhydride-metabolic] was prepared by replacing IⅤ11 with metatoluidine.

[0088] Comparative Example 3: Poly[3,3',4,4'-benzophenone tetracarboxylic acid dianhydride-diaminodiphenyl ether].

[0089] Following the method of Example 8, poly[3,3',4,4'-benzophenone tetracarboxylic acid dianhydride-diaminodiphenyl ether] was prepared by replacing IⅤ11 with diaminodiphenyl ether.

[0090] Application Examples:

[0091] The polyimide films obtained in the examples and comparative examples were subjected to various performance tests. Specific methods for measuring glass transition temperature and light transmittance are detailed in CN111205458 A. The method for determining the hygroscopic expansion coefficient is as follows:

[0092] To prevent the polyimide film from loosening or collapsing, the humidity was first adjusted to 3% relative humidity (RH) to allow it to fully absorb moisture, and its dimensions were measured. Then, the humidity was adjusted to 90% RH, and the film was again saturated with moisture before measuring its dimensions. By comparing these two measurements, the rate of dimensional change at 90% RH with a relative humidity difference of 87% could be determined.

[0093] The test results are shown in the table below.

[0094]

[0095] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present 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. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A polyimide film, characterized in that, Includes the compound shown in Formula I, or the compound shown in Formula I', or the compound shown in Formula I''; the polyimide film has a hygroscopic expansion coefficient of less than 6 ppm / RH%; in, R1 and R3 are each independently selected from -H or -OCH3; R2 is selected from -H, -CH3, or -CH2CH3; Ar selected ; n is selected from 2 to 30.

2. The polyimide film according to claim 1, characterized in that, The compound shown in Formula I, the compound described in Formula I', and the compound shown in Formula I'' are any one of Formula I1 to Formula I12, where n is selected from 2 to 30; 。 3. The polyimide film according to claim 1, characterized in that, The compound represented by Formula I, the compound represented by Formula I', and the compound represented by Formula I'' are Formula I2, Formula I9, or Formula I11, wherein n is selected from 2 to 30; 。 4. The polyimide film according to any one of claims 1-3, characterized in that, The method for preparing the compound includes the following steps: A solution containing polyamic acid compound V is obtained by condensing aryl diamine compound IV with a dianhydride compound; or, a solution containing polyamic acid compound V' is obtained by condensing aryl diamine compound IV' with a dianhydride compound; or, a solution containing polyamic acid compound V'' is obtained by condensing aryl diamine compound IV'' with a dianhydride compound. in, R1 and R3 are each independently selected from -H or -OCH3; R2 is selected from -H, -CH3, or -CH2CH3; Ar selected ; n is selected from 2 to 30.

5. The polyimide film according to claim 4, characterized in that, The dianhydride compound is 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride.

6. The polyimide film according to claim 4, characterized in that, The molar ratio of the aryl diamine compound IV, aryl diamine compound IV' or aryl diamine compound IV'' to the dianhydride compound is 1:0.5-2.

7. The polyimide film according to claim 4, characterized in that, The molar ratio of the aryl diamine compound IV, aryl diamine compound IV' or aryl diamine compound IV'' to the dianhydride compound is 1:0.8-1.

2.

8. The polyimide film according to claim 4, characterized in that, The solvent for the condensation reaction is the polar aprotic solvent N-methylpyrrolidone; the ratio of the amount of aryl diamine compound IV, aryl diamine compound IV' or aryl diamine compound IV'' to the solvent is 0.01-0.2 mol / 200 mL.

9. The polyimide film according to claim 4, characterized in that, The condensation reaction temperature is 20-60℃.

10. The polyimide film according to claim 4, characterized in that, Also includes: Polyamic acid compound V, polyamic acid compound V', or aryl diamine compound IV'' undergoes a thermal imidization reaction at high temperature to obtain the compound shown in Formula I, the compound described in Formula I', or the compound shown in Formula I''.

11. The polyimide film according to claim 1, characterized in that, The tensile modulus of the polyimide film is 8-11 GPa.

12. The polyimide film according to claim 1, characterized in that, The tensile strength of the polyimide film is 400-450 MPa.

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