A meta-methyl benzoate-alkyl thiophene copolymer and a method for preparing the same
By designing the DA structure of meta-methyl benzoate-alkylthiophene copolymer, the problem of low doping efficiency in traditional polythiophene materials was solved, achieving efficient charge transport and improved conductivity.
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
- 2026-06-05
AI Technical Summary
Traditional polythiophene materials have low doping efficiency during the doping process, and the dopant is difficult to effectively penetrate and enter the interior of the polymer, resulting in limited improvement in conductivity.
A meta-methyl benzoate-alkylthiophene copolymer is used to form a DA structure by meta-linking methyl benzoate and alkylthiophene, which maintains the planarity and electron-deficient properties of the copolymer and improves the utilization rate of dopant and charge transport efficiency.
High-concentration doping and efficient charge transport were achieved, which improved conductivity and doping efficiency.
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Figure CN122145771A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thiophene copolymer technology, and particularly relates to a meta-methyl benzoate-alkyl thiophene copolymer and its preparation method. Background Technology
[0002] Since their discovery in the 1970s, conductive polymers have shown broad application prospects in fields such as organic optoelectronic devices, sensors, antistatic coatings, supercapacitors, and biomedical engineering due to their combination of the conductivity of metals and the flexibility and processability of organic polymers. Among them, polythiophene and its derivatives have become one of the most widely studied conductive polymer systems due to their good environmental stability, tunable band gap structure, and excellent film-forming properties.
[0003] Doping is a key method for endowing polythiophene with electrical conductivity. Through oxidative or reduction doping, charge carriers can be introduced into the polymer backbone, forming polarons or bipolarons, thereby achieving a transition to an insulating state conductor. However, traditional polythiophene materials generally suffer from low doping efficiency during the doping process. On the one hand, the molecular chain aggregation structure of conventional homopolymer thiophene is dense, making it difficult for dopant molecules to effectively penetrate and enter the polymer interior; on the other hand, the regularity of the polymer backbone and the electron cloud distribution significantly affect the doping reactivity, resulting in low dopant utilization and uneven doping. Even with increased dopant dosage, the improvement in material conductivity is very limited.
[0004] Therefore, how to effectively improve the doping efficiency of thiophene polymers to enhance their conductivity 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 meta-methyl benzoate-alkylthiophene copolymer and its preparation method. The meta-methyl benzoate-alkylthiophene copolymer has a DA structure, and methyl benzoate is linked to alkylthiophene at the meta position, which can maintain the planarity of the copolymer and the electron-deficient characteristics of the methyl benzoate unit. This is beneficial for charge transport within the polymer molecule and for achieving high-concentration doping and efficient charge transport between the polymer and the dopant.
[0006] The purpose of this invention is to provide a methyl meta-benzoate-alkylthiophene 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 12 carbon atoms.
[0009] In some embodiments of the present invention, the alkyl group is a straight-chain alkyl group having 4 to 6 carbon atoms, such as n-hexyl, n-pentyl, or n-butyl.
[0010] In some embodiments of the present invention, the copolymer has a number-average molecular weight of 3-35 kDa and a molecular weight distribution of 1.05-2.5. Preferably, the number-average molecular weight is 3-10 kDa and the molecular weight distribution is 1.05-1.6.
[0011] In some embodiments of the present invention, the raw materials for preparing the copolymer include methyl 3,5-dibromobenzoate and alkyl-substituted thiophene. .
[0012] Another object of the present invention is to provide a method for preparing the above-mentioned methyl meta-benzoate-alkylthiophene copolymer, which includes the following steps:
[0013] In the presence of catalysts and auxiliaries, methyl 3,5-dibromobenzoate and alkyl-substituted thiophene A polymerization reaction occurs to obtain the methyl meta-benzoate-alkylthiophene copolymer.
[0014] In some embodiments of the present invention, the molar ratio of the methyl 3,5-dibromobenzoate to the alkyl-substituted thiophene is 1:0.9~1.1.
[0015] 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):
[0016] 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.
[0017] 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 methyl 3,5-dibromobenzoate and the alkyl-substituted thiophene.
[0018] In some embodiments of the present invention, the additives include inorganic bases, organic acids, and solvents.
[0019] In some embodiments of the present invention, the inorganic base is selected from potassium carbonate.
[0020] 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 methyl 3,5-dibromobenzoate and the alkyl-substituted thiophene.
[0021] In some embodiments of the present invention, the organic acid is selected from pivalic acid.
[0022] 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 methyl 3,5-dibromobenzoate and the alkyl-substituted thiophene.
[0023] In some embodiments of the present invention, the solvent is selected from at least one of toluene and N,N-dimethylacetamide.
[0024] In some embodiments of the present invention, the polymerization reaction is carried out at a temperature of 80-120°C.
[0025] In some embodiments of the present invention, the polymerization reaction takes 18 to 30 hours.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] The meta-methyl benzoate-alkylthiophene copolymer of the present invention has a DA structure, and the methyl benzoate is connected to the alkylthiophene through the meta position, which can maintain the planarity of the copolymer and the electron-deficient characteristics of the methyl benzoate unit. This is beneficial to the charge transport within the polymer molecule and to achieving high-concentration doping and efficient charge transport between the polymer and the dopant, thereby achieving higher doping efficiency and obtaining higher conductivity under the same dopant concentration conditions. Attached Figure Description
[0028] 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:
[0029] Figure 1 The meta-benzoate-alkylthiophene copolymer obtained in Example 2 of this invention 1 H NMR spectrum. Detailed Implementation
[0030] 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.
[0031] Unless otherwise specified, all raw materials used in this invention are obtained commercially.
[0032] The structure of the palladium catalyst C1 of the present invention is shown below: ;
[0033] The structure of the palladium catalyst C2 of the present invention is shown below: ;
[0034] The structure of the palladium catalyst C3 of the present invention is shown below: .
[0035] Example 1
[0036] This embodiment provides a meta-methyl benzoate-alkylthiophene copolymer, the preparation method of which includes the following steps:
[0037] Weigh 0.25 mmol of 3-n-butylthiophene, 0.25 mmol of methyl 3,5-dibromobenzoate, 0.15 mmol of tertivalic 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 a yellow-green solid powder, which is the methyl benzoate-alkylthiophene copolymer (yield 48%), and its structure is shown below:
[0038] .
[0039] Example 2
[0040] This embodiment provides a meta-methyl benzoate-alkylthiophene copolymer, the preparation method of which includes the following steps:
[0041] Weigh 0.25 mmol of 3-hexylthiophene, 0.25 mmol of methyl 3,5-dibromobenzoate, 0.15 mmol of tertivalic 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 a yellow-green solid powder, which is the methyl benzoate-alkylthiophene copolymer (yield 55%), and its structure is shown below:
[0042] .
[0043] In addition, the meta-benzoate-alkylthiophene copolymer 1 The H NMR analysis results are as follows: Figure 1 As shown, by Figure 1 It can be seen that the integral area of the benzene ring H at a chemical shift of 7.99~8.12 ppm, the integral area of the methyl H at a chemical shift of 3.89~3.91 ppm, and the integral area of the methylene H connected to thiophene are approximately 3:3:2. This indicates that methyl benzoate and alkyl-substituted thiophene have been successfully copolymerized. That is, Example 2 of the present invention successfully prepared a meta-methyl benzoate-alkyl thiophene copolymer.
[0044] Example 3
[0045] This embodiment provides a meta-methyl benzoate-alkylthiophene copolymer, the preparation method of which includes the following steps:
[0046] Weigh 0.25 mmol of 3-n-octylthiophene, 0.25 mmol of methyl 3,5-dibromobenzoate, 0.15 mmol of tertivalic 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 2 mL of N,N-dimethylacetamide and 2 mL of toluene. 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 a yellow-green solid powder, which is the methyl benzoate-alkylthiophene copolymer (yield 62%), and its structure is shown below:
[0047] .
[0048] Example 4
[0049] This embodiment provides a meta-methyl benzoate-alkylthiophene copolymer, the preparation method of which includes the following steps:
[0050] Weigh 0.25 mmol of 3-dodecylthiophene, 0.25 mmol of methyl 3,5-dibromobenzoate, 0.15 mmol of tertivalic 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 a yellow-green solid powder, which is the methyl benzoate-alkylthiophene copolymer (yield 70%), and its structure is shown below:
[0051] .
[0052] Example 5
[0053] This embodiment provides a meta-methyl benzoate-alkylthiophene copolymer, the preparation method of which includes the following steps:
[0054] Weigh 0.25 mmol of 3-(2-ethylhexyl)thiophene, 0.25 mmol of methyl 3,5-dibromobenzoate, 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 a yellow-green solid powder, which is the methyl benzoate-alkylthiophene copolymer (yield 58%), and its structure is shown below:
[0055] .
[0056] Example 6
[0057] This embodiment provides a meta-methyl benzoate-alkylthiophene copolymer, the preparation method of which includes the following steps:
[0058] Weigh 0.25 mmol of 3-n-hexylthiophene, 0.25 mmol of methyl 3,5-dibromobenzoate, 0.15 mmol of tertivalic 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. Then, the reaction system is heated to 110°C and reacted at this temperature for 12 h. After the reaction is completed, 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 a yellow-green solid powder, which is the methyl benzoate-alkylthiophene copolymer (yield 63%), and its structure is as in Example 2.
[0059] Comparative Example 1
[0060] The copolymer in this comparative example is the ester-based thiophene-hexylthiophene copolymer obtained in Example 5 of CN119019651A, and its structure is shown below:
[0061] Among them, x=16mmol%, y=84mmol%, number-average molecular weight Mn is 7.4kDa, and PDI is 2.0.
[0062] The performance tests are as follows, and the results are shown in Table 1:
[0063] 1. GPC analysis was performed on the methyl meta-benzoate-alkylthiophene copolymers obtained in Examples 1-6 above to determine their molecular weight and molecular weight distribution;
[0064] 2. The meta-benzoate methyl ester-alkylthiophene copolymers obtained in Examples 1-6 and the ester-thiophene-hexylthiophene copolymer of Comparative Example 1 were respectively prepared into 0.2 mg / mL solutions with chlorobenzene and coated onto a 20 mm × 20 mm glass substrate by spin coating. After the solvent evaporated naturally, the copolymer films were annealed to form the corresponding copolymer films. Then, the copolymer films were immersed in FeCl3 CH3CN solutions of different concentrations (0 mM, 20 mM, 50 mM, 100 mM) for 2 min. After being taken out, they were immersed in pure CH3CN for 20 s. After the surface was dried, they were dried in an oven at 60 °C for 5 min. The conductivity was measured by the four-probe method.
[0065] Table 1: Properties of different alkylthiophene copolymers
[0066]
[0067] As shown in Table 1, the meta-methyl benzoate-alkyl thiophene copolymers obtained in Examples 1-6 of the present invention have high doping efficiency and can achieve higher conductivity under the same dopant concentration, especially the copolymers of Examples 1-2 obtained from C4 and C6 linear alkyl thiophenes.
[0068] 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 meta-methyl benzoate-alkylthiophene 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 12 carbon atoms.
2. The meta-benzoate-alkylthiophene copolymer according to claim 1, characterized in that, The alkyl group is a straight-chain alkyl group having 4 to 6 carbon atoms.
3. The meta-methyl benzoate-alkylthiophene copolymer according to claim 1, characterized in that, The copolymer has a number-average molecular weight of 3-35 kDa and a molecular weight distribution of 1.05-2.
5.
4. The meta-benzoate-alkylthiophene copolymer according to claim 1, characterized in that, The copolymer has a number-average molecular weight of 3-10 kDa and a molecular weight distribution of 1.05-1.
6.
5. The meta-methyl benzoate-alkylthiophene copolymer according to claim 1, characterized in that, The raw materials for preparing the copolymer include methyl 3,5-dibromobenzoate and alkyl-substituted thiophene. .
6. The method for preparing the meta-methyl benzoate-alkylthiophene copolymer according to any one of claims 1 to 5, characterized in that, Includes the following steps: In the presence of catalysts and auxiliaries, methyl 3,5-dibromobenzoate and alkyl-substituted thiophene A polymerization reaction occurs to obtain the methyl meta-benzoate-alkylthiophene copolymer.
7. The method for preparing the meta-methyl benzoate-alkylthiophene copolymer according to claim 6, characterized in that, The molar ratio of the methyl 3,5-dibromobenzoate to the alkyl-substituted thiophene is 1:0.9~1.
1.
8. The method for preparing the meta-methyl benzoate-alkylthiophene 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 methyl 3,5-dibromobenzoate and the alkyl-substituted thiophene; And / or, the additives include inorganic bases, organic acids, and solvents.
9. The method for preparing the meta-methyl benzoate-alkylthiophene 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 methyl 3,5-dibromobenzoate 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 methyl 3,5-dibromobenzoate 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 meta-methyl benzoate-alkylthiophene 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.