A biphenyl-alkyl substituted thiophene copolymer and a method for preparing the same
By preparing biphenyl-alkyl-substituted thiophene copolymers, the balance between conductivity and processing performance of P3ATs was solved, achieving high conductivity and long-term stability, making them suitable for complex application environments of organic electronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHAIN WALK NEW MATERIAL TECH (GUANGZHOU) CO LTD
- Filing Date
- 2026-05-06
- Publication Date
- 2026-06-02
AI Technical Summary
Existing P3ATs have a problem in balancing the processing performance and conductivity improvement, and the conductivity is easy to decrease after chemical doping treatment, making it difficult to meet the long-term stability requirements of complex application environments.
By employing the alternating structure of biphenyl-alkyl-substituted thiophene copolymers, utilizing the rigidity of biphenyl and the flexibility of alkyl-substituted thiophene, a copolymer with a regular structure is prepared by catalyzing the polymerization reaction of 4,4'-dibromobiphenyl with alkyl-substituted thiophene using palladium catalysts, forming a uniform and defect-free film.
While improving electrical conductivity, it maintains the long-term stability of the material, making it suitable for complex application environments and ensuring the continuity of electrical conductivity.
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Figure CN122127580A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thiophene copolymer technology, and particularly relates to a biphenyl-alkyl-substituted thiophene copolymer and its preparation method. Background Technology
[0002] Conductive polymers combine the conductivity of metals with the flexibility and processability of polymers, showing great promise for applications in organic electronic devices. Among numerous conductive polymer systems, poly(3-alkylthiophene)P3ATs have become one of the most widely used conjugated polymer materials due to their excellent solution processability, tunable band structure, and relatively high carrier mobility. By introducing alkyl side chains of different lengths at the 3-position of the thiophene ring, P3ATs can achieve melt and solution processing while maintaining good conductivity, providing a material basis for the low-cost fabrication of organic electronic devices.
[0003] However, two interconnected technical bottlenecks in the conductivity of P3ATs still hinder their practical application in a wider range of scenarios. First, to achieve high conductivity, P3ATs typically require chemical doping to generate free charge carriers. While introducing conductive charge carriers, the dopant molecules often physically disrupt the ordered stacking of polymer chains. This is especially true for alkyl-substituted thiophene polymers. Although the flexible, long-chain alkyl side chains impart good solubility and melt processing properties, their steric hindrance causes the polymer backbone to become distorted, disrupting the regularity of the π-π conjugated structure and limiting the intra-chain transport efficiency of charge carriers. Therefore, it is often difficult to achieve a balance between processing performance and improved conductivity. Second, for chemically doped P3ATs, repeated heating and cooling processes pose a risk of conformational changes in the polymer backbone, leading to the dissociation of dopant from the chain, which significantly reduces conductivity. This is not conducive to the complex practical applications of devices based on these P3ATs.
[0004] Therefore, how to develop a new type of conductive polymer material that can achieve higher conductivity while ensuring excellent solution processability and maintaining high conductivity after multiple thermal cycles, so as to meet the long-term stability requirements of conductive materials in complex application environments, is a technical problem that urgently needs to be solved in this field. Summary of the Invention
[0005] To address the shortcomings of the prior art, this invention provides a biphenyl-alkyl-substituted thiophene copolymer and its preparation method. The biphenyl-alkyl-substituted thiophene copolymer has an alternating structure of biphenyl and alkyl-substituted thiophene. On the one hand, the biphenyl structure can increase the planarity and rigidity of the copolymer, resulting in high charge transport efficiency and improved conductivity. On the other hand, the copolymer as a whole has an alternating structure of rigid biphenyl and processable thiophene. The interaction between the two is beneficial to obtaining a uniform and defect-free film, which can maintain stable performance for a long time even when used in complex application environments.
[0006] The purpose of this invention is to provide a biphenyl-alkyl-substituted thiophene copolymer, the structural formula of which is shown in formula (I):
[0007] Equation (Ⅰ);
[0008] Wherein, R is selected from one of the alkyl groups having 4 to 8 carbon atoms.
[0009] In some embodiments of the present invention, the alkyl group is a straight-chain alkyl group, such as n-octyl, n-hexyl, n-pentyl, or n-butyl.
[0010] In some embodiments of the present invention, the number of carbon atoms is 4, 5 or 6, for example, R is a 2-methylpentyl or 2-methylbutyl structure.
[0011] In some embodiments of the present invention, the copolymer has a weight-average molecular weight of 8-20 kDa and a molecular weight distribution of 1.5-3. Preferably, the weight-average molecular weight is 10-16 kDa and the molecular weight distribution is 1.5-2.2.
[0012] In some embodiments of the present invention, the raw materials for preparing the copolymer include 4,4'-dibromobiphenyl and alkyl-substituted thiophene. .
[0013] Another object of the present invention is to provide a method for preparing the above-mentioned biphenyl-alkyl-substituted thiophene copolymer, which includes the following steps:
[0014] Under the action of catalysts and auxiliaries, 4,4'-dibromobiphenyl and alkyl-substituted thiophene A polymerization reaction occurs to obtain the biphenyl-alkyl-substituted thiophene copolymer.
[0015] In some embodiments of the present invention, the molar ratio of the 4,4'-dibromobiphenyl to the alkyl-substituted thiophene is 1:0.9~1.1.
[0016] In some embodiments of the present invention, the catalyst comprises a palladium-based catalyst. Preferably, the palladium-based catalyst has the structural formula shown in formula (II):
[0017] Equation (II); where R 1 R 2 It can be hydrogen, methyl, ethyl, or isopropyl independently, and R 1 R 2 They are not both hydrogen.
[0018] In some embodiments of the present invention, the amount of the catalyst is 0.5 to 4 mol% of the sum of the amounts of the 4,4'-dibromobiphenyl and the alkyl-substituted thiophene.
[0019] In some embodiments of the present invention, the additives include inorganic bases, organic acids, and solvents.
[0020] In some embodiments of the present invention, the inorganic base is selected from potassium carbonate.
[0021] In some embodiments of the present invention, the amount of the inorganic base is 1.2 to 2 times the sum of the amounts of the 4,4'-dibromobiphenyl and the alkyl-substituted thiophene.
[0022] In some embodiments of the present invention, the organic acid is selected from pivalic acid.
[0023] In some embodiments of the present invention, the amount of organic acid used is 10 to 50 mol% of the sum of the amounts of the 4,4'-dibromobiphenyl and the alkyl-substituted thiophene.
[0024] In some embodiments of the present invention, the solvent is selected from at least one of toluene and N,N-dimethylacetamide.
[0025] In some embodiments of the present invention, the polymerization reaction is carried out at a temperature of 80-120°C.
[0026] In some embodiments of the present invention, the polymerization reaction takes 18 to 30 hours.
[0027] Compared with the prior art, the present invention has the following beneficial effects:
[0028] The biphenyl-alkyl-substituted thiophene copolymer of the present invention has a regular structure, which can achieve improved electrical conductivity. At the same time, it retains the rigidity of biphenyl and the processability of alkyl-substituted thiophene, and can form a more uniform and defect-free film, which is beneficial for maintaining its stable performance for a long time even when used in complex application environments. Attached Figure Description
[0029] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings:
[0030] Figure 1 The biphenyl-alkyl-substituted thiophene copolymer obtained in Example 3 of this invention 1 H NMR spectrum. Detailed Implementation
[0031] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.
[0032] Unless otherwise specified, all raw materials used in this invention are obtained commercially.
[0033] The structure of the palladium catalyst C1 of the present invention is shown below: ;
[0034] The structure of the palladium catalyst C2 of the present invention is shown below: ;
[0035] The structure of the palladium catalyst C3 of the present invention is shown below: .
[0036] Example 1
[0037] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0038] Weigh 0.25 mmol of 3-n-octylthiophene, 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of pentylamino acid, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C1, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 60%), the structure of which is shown below:
[0039] .
[0040] Example 2
[0041] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0042] Weigh 0.25 mmol of 3-(2-ethylhexyl)thiophene, 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of tervastatinic acid, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C2, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 61%), the structure of which is shown below:
[0043] .
[0044] Example 3
[0045] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0046] Weigh 0.25 mmol of 3-hexylthiophene, 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of tervastatinic acid, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C3, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 68%), the structure of which is shown below:
[0047] .
[0048] In addition, this biphenyl-alkyl-substituted thiophene copolymer was subjected to 1 The results of the H NMR analysis are as follows: Figure 1 As shown. By Figure 1It can be seen that the integral area of the benzene ring H at a chemical shift of 7.5~8 ppm is about 4 times the integral area of the methylene H attached to thiophene. This indicates that biphenyl and alkyl-substituted thiophene have been successfully copolymerized, that is, the biphenyl-alkyl-substituted thiophene copolymer was successfully prepared in Example 3.
[0049] Example 4
[0050] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0051] Weigh 0.25 mmol of 3-(2-methylpentyl)thiophene, 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of terpentine, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C1, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 65%), the structure of which is shown below:
[0052] .
[0053] Example 5
[0054] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0055] Weigh 0.25 mmol of 3-n-pentylthiophene, 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of pentylamino acid, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C1, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 60%), the structure of which is shown below:
[0056] .
[0057] Example 6
[0058] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0059] Weigh 0.25 mmol of 3-(2-methylbutylthiophene), 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of tervastatinic acid, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C1, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 63%), the structure of which is shown below:
[0060] .
[0061] Example 7
[0062] This embodiment provides a biphenyl-alkyl-substituted thiophene copolymer, the preparation method of which includes the following steps:
[0063] Weigh 0.25 mmol of 3-n-butylthiophene, 0.25 mmol of 4,4'-dibromobiphenyl, 0.15 mmol of tervastatinic acid, 0.75 mmol of anhydrous potassium carbonate, and 0.01 mmol of palladium catalyst C1, and transfer them sequentially to a reactor. Then add 4 mL of N,N-dimethylacetamide. The reaction system is purged multiple times with N2 to remove air. The reaction system is heated to 100 °C and reacted at this temperature for 24 h. After the reaction is complete, the reaction solution is poured into a large amount of methanol to settle, filtered, and the filter cake is dissolved in N,N-dimethylacetamide and then precipitated again with a large amount of methanol. This process is repeated twice. The filter cake is crushed, added to a beaker containing water, stirred for 30 min, filtered, and the filter cake is washed with methanol and dried to obtain the biphenyl-alkyl-substituted thiophene copolymer (yield 61%), the structure of which is shown below:
[0064] .
[0065] The performance tests are as follows, and the results are shown in Table 1:
[0066] 1. GPC analysis was performed on the biphenyl-alkyl-substituted thiophene copolymers obtained in Examples 1-7 above;
[0067] 2. The biphenyl-alkyl-substituted thiophene copolymers obtained in Examples 1-7 were each prepared into 0.2 mg / mL solutions with chlorobenzene and spin-coated onto 20 mm × 20 mm glass substrates. After the solvent evaporated naturally, the substrates were annealed to form corresponding copolymer films, and their initial conductivity was measured using the four-probe method. Further, copolymer films obtained using the same method were subjected to a thermal cycling test. The temperature range of the test was set to -40°C to +85°C, and the temperature change rate was 5°C / min. After 500 cycles, the conductivity was measured again using the four-probe method, and the retention rate relative to the initial conductivity was calculated. Additionally, a doped film obtained by treating a P3HT film in a dopant solution (0.25 mg / mL F4TCNQ acetonitrile solution) for 5 seconds was used as a reference example.
[0068] Table 1:
[0069]
[0070] As shown in Table 1, the films formed by the biphenyl-alkyl-substituted thiophene copolymers obtained in Examples 1-7 of the present invention have high conductivity and thermal cycling stability, meeting the requirements of long-term stability of conductive materials in actual complex application environments.
[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that after reading this application specification, they can still modify or make equivalent substitutions to the specific implementation of the present invention, but these modifications or changes do not depart from the protection scope of the pending claims of the present invention.
Claims
1. A biphenyl-alkyl-substituted thiophene copolymer, characterized in that, Its structural formula is shown in equation (Ⅰ): Equation (Ⅰ); Wherein, R is selected from one of the alkyl groups having 4 to 8 carbon atoms.
2. The biphenyl-alkyl-substituted thiophene copolymer according to claim 1, characterized in that, The alkyl group is a straight-chain alkyl group.
3. The biphenyl-alkyl-substituted thiophene copolymer according to claim 1, characterized in that, The number of carbon atoms is 4, 5, or 6.
4. The biphenyl-alkyl-substituted thiophene copolymer according to claim 1, characterized in that, The copolymer has a weight-average molecular weight of 8-20 kDa and a molecular weight distribution of 1.5-3.
5. The biphenyl-alkyl-substituted thiophene copolymer according to claim 1, characterized in that, The copolymer is prepared from raw materials including 4,4'-dibromobiphenyl and alkyl-substituted thiophene. .
6. The method for preparing the biphenyl-alkyl-substituted thiophene copolymer according to any one of claims 1 to 5, characterized in that, Includes the following steps: Under the action of catalysts and auxiliaries, 4,4'-dibromobiphenyl and alkyl-substituted thiophene A polymerization reaction occurs to obtain the biphenyl-alkyl-substituted thiophene copolymer.
7. The method for preparing the biphenyl-alkyl-substituted thiophene copolymer according to claim 6, characterized in that, The molar ratio of the 4,4'-dibromobiphenyl to the alkyl-substituted thiophene is 1:0.9~1.
1.
8. The method for preparing the biphenyl-alkyl-substituted thiophene copolymer according to claim 6, characterized in that, The catalyst includes palladium-based catalysts; And / or, the amount of the catalyst used is 0.5 to 4 mol% of the sum of the molar amounts of the 4,4'-dibromobiphenyl and the alkyl-substituted thiophene; And / or, the additives include inorganic bases, organic acids, and solvents.
9. The method for preparing the biphenyl-alkyl-substituted thiophene copolymer according to claim 8, characterized in that, The inorganic base is selected from potassium carbonate; And / or, the amount of the inorganic base is 1.2 to 2 times the sum of the amounts of the 4,4'-dibromobiphenyl and the alkyl-substituted thiophene; And / or, the organic acid is selected from pivalic acid; And / or, the amount of the organic acid used is 10-50 mol% of the sum of the amounts of the 4,4'-dibromobiphenyl and the alkyl-substituted thiophene; And / or, the solvent is selected from at least one of toluene and N,N-dimethylacetamide.
10. The method for preparing the biphenyl-alkyl-substituted thiophene copolymer according to claim 6, characterized in that, The polymerization reaction is carried out at a temperature of 80-120°C; and / or the polymerization reaction is carried out for a duration of 18-30 hours.