High conductivity polybenzodifuran dione and cyclic voltammetry preparation method thereof

Abstract

The application discloses a kind of high conductivity polybenzodifuran dione and cyclic voltammetry preparation method thereof, belong to organic conductive polymer material preparation technical field, method includes: benzodifuran dione (BFDO) monomer and supporting electrolyte are dissolved in polar aprotic solvent, obtain electrolyte;With platinum electrode immersed in electrolyte as working electrode and counter electrode, with saturated calomel electrode as reference electrode, constitute three-electrode system;In air atmosphere, cyclic voltammetry scanning is applied to working electrode, carries out electrochemical polymerization reaction, and polybenzodifuran dione (PBFDO) is directly generated on electrode surface;After filtration, washing and drying, high conductivity polybenzodifuran dione film is obtained;The film is n-type conductive polymer, and the conductivity is 2.2~428.3 S / cm.Cyclic voltammetry electrochemical polymerization method is used, and no additional oxidizing agent is needed, and the polymerization process completely depends on the electron transfer reaction on the electrode surface, to realize the direct polymerization of polybenzodifuran dione on electrode.

Description

Technical Field

[0001] This invention belongs to the field of organic conductive polymer material preparation technology, specifically relating to a high-conductivity polybenzodifurandione and its cyclic voltammetric preparation method. Background Technology

[0002] The scarcity of n-type conductive polymers with high electrical conductivity is a key material bottleneck restricting the advancement of organic electronics towards symmetric complementary device architectures. In recent years, breakthroughs in polybenzodifurandione (Nature 2022, 611, 271) have opened up new prospects for n-type conductive polymer materials due to their excellent electrical conductivity and outstanding stability. However, current mainstream chemical synthesis routes generally rely on high temperature, high pressure, oxygen-free environments, and the use of catalysts. While these conditions help achieve high electrical conductivity, they also involve complex processes and high costs, limiting their large-scale application.

[0003] Chinese patent application CN105887126B discloses a method for preparing poly(3,4-ethylenedioxythiophene) (PEDOT) nanowire thin films, synthesized at room temperature using electrochemical polymerization (cyclic voltammetry or potentiostatic method). The monomer used is EDOT (a p-type conductive polymer precursor), the supporting electrolyte is an ionic liquid, and the solvent is dichloromethane. The resulting PEDOT thin film has a nanowire structure and exhibits good electrochromic properties, suitable for electrochromic devices. However, this method only relates to the synthesis of the p-type conductive polymer PEDOT and does not involve n-type conductive polymers. The polymerization system depends on organic solvents and ionic liquids, and the resulting thin films are mainly used in optical devices, not in the preparation of high-conductivity n-type polymers or capacitor applications. It fails to address the problems of difficult synthesis, porous structure, and poor conductivity of n-type conductive polymers. Chinese patent application CN119800385B discloses a method for preparing highly dense and stable conductive polymer thin films based on electrochemical polymerization. First, PBFDO (n-type conductive polymer) is prepared on a chemically polymerized foil in situ, and then modified with EDOT via electrochemical polymerization. The resulting film exhibits high density and, when applied to aluminum electrolytic capacitors, improves capacitor stability and reduces ESR and leakage current. Although PBFDO is involved, its preparation still relies on chemical oxidative polymerization, requiring the use of oxidants (such as selenium dioxide). The reaction conditions are complex, leading to issues such as impurity introduction, raw material waste, and non-reusability. The electrochemical polymerization step is only used to modify the PBFDO layer and does not achieve direct electrochemical polymerization of BFDO monomers. The method is cumbersome, involving multiple impregnation, drying, and repeated cycles, making it unsuitable for large-scale continuous production.

[0004] Electrochemical polymerization is considered a promising alternative synthesis strategy due to its advantages of mild conditions, lack of external oxidants, and pure products. However, to date, there are no publicly reported successful electrochemical polymerization methods for BFDO monomers to prepare PBFDO with a dense structure and high conductivity. The core challenge in this field is designing a suitable electrochemical system to activate BFDO monomers under mild conditions, achieving the controllable synthesis of dense, high-conductivity PBFDO polymers. Potentiostatic polymerization, with its high and constant applied potential, can lead to excessively rapid monomer oxidation, resulting in a large number of oligomers or loosely structured polymers, thus affecting polymer density. Furthermore, this method has limited monitoring capabilities during polymerization. Therefore, developing a PBFDO polymer preparation method that maintains the advantages of electrochemical synthesis while enabling real-time monitoring and fine-tuning of the process is crucial for in-depth research into its polymerization mechanism and optimization of polymer structure and properties, and represents a key technical problem that needs to be solved in this field. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a high-conductivity polybenzodifuran dione and its cyclic voltammetric preparation method, so as to solve the technical problem of how to directly polymerize BFDO monomers by electrochemical means under conditions of no dependence on chemical oxidants, high temperature and high pressure and oxygen-free environment, to prepare PBFDO polymers with dense structure and high conductivity.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a cyclic voltammetric preparation method for high-conductivity polybenzodifurandione, comprising: dissolving benzodifurandione monomer and supporting electrolyte in a polar aprotic solvent to prepare an electrolyte; using a platinum electrode immersed in the electrolyte as the working electrode and counter electrode, and a saturated calomel electrode as the reference electrode to form a three-electrode system; applying cyclic voltammetry to the working electrode in an air atmosphere to carry out an electrochemical polymerization reaction, directly generating polybenzodifurandione in the solution; and obtaining a high-conductivity polybenzodifurandione film after filtration, washing, and drying. The high-conductivity polybenzodifurandione film is an n-type conductive polymer with a conductivity of 2.2~428.3 S / cm.

[0007] Preferably, the potential scan range of the cyclic voltammetric scan is -3.5 to 3.5 V.

[0008] Preferably, the scanning rate of the cyclic voltammetric scan is 5-50 mV / s.

[0009] Preferably, the number of cyclic voltammetric scans is 10-50 cycles.

[0010] Preferably, the polar aprotic solvent is dimethyl sulfoxide, a mixed solution of dimethyl sulfoxide and N,N-dimethylformamide, or a mixed solution of dimethyl sulfoxide and acetonitrile.

[0011] Preferably, the electrolyte is any one of LiCl, NH4Cl, and NaNO3.

[0012] Preferably, the molar concentration of the electrolyte in the electrolyte solution is 0.1-0.6 mol / L.

[0013] Preferably, the mass concentration of the benzodifurandione monomer in the electrolyte is 8-20 mg / mL.

[0014] Preferably, the drying temperature is 60-100℃.

[0015] The present invention discloses a high conductivity polybenzodifurandione, which is prepared by the above-mentioned cyclic voltammetry preparation method for high conductivity polybenzodifurandione.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a cyclic voltammetric method for preparing high-conductivity polybenzodifurandione (PBFDO). Employing cyclic voltammetric electrochemical polymerization, the PBFDO monomer is directly activated via electron transfer reaction on the electrode surface without the addition of any external chemical oxidants. This enables the electrochemical synthesis of PBFDO thin films under mild conditions (room temperature and air atmosphere). This method eliminates the dependence on catalysts, high temperature and pressure, and oxygen-free environments required by traditional methods, providing a green and low-cost synthesis route. The polymerization reaction directly generates PBFDO in solution, and the pure product can be obtained through simple filtration and washing, avoiding the introduction of impurities and complex purification steps in chemical oxidation methods. The obtained PBFDO is an n-type conductive polymer with a conductivity of up to 428.3 S / cm, confirming the feasibility of this electrochemical route and yielding high-performance materials. This method can be carried out in an air atmosphere, overcoming the limitation of strictly oxygen-free conditions required for the chemical polymerization of PBFDO, significantly reducing operational difficulty and equipment requirements.

[0017] Furthermore, cyclic voltammetry scans over a wide potential range of -3.5 to 3.5 V ensured that the BFDO monomer underwent sufficient redox processes, thereby initiating polymerization on the electrode surface. The negative potential of -3.5 V and the positive potential of 3.5 V covered the oxidation polymerization potential of the BFDO monomer and the possible reduction dedoping process, providing sufficient electrochemical driving force for monomer activation and polymer formation. The cyclic scanning over a wide potential range helped to regulate the redox state of the polymer, affecting its doping degree and chain structure, and thus affecting the conductivity of the final product. The PBFDO obtained in Example 7 achieved a conductivity of 171.7 S / cm, indicating that this potential window can effectively support the formation of high-conductivity polymers.

[0018] Furthermore, by adjusting the scan rate, the diffusion time of monomers on the electrode surface, the reaction time, and the growth rate of polymer chains can be controlled, thereby affecting the microstructure of the polymer. Lower scan rates provide more sufficient diffusion and reaction time for monomers, which is beneficial for the formation of dense polymers. Examples 4 (5 mV / s) and 6 (5 mV / s) yielded conductivity of 98.4 S / cm and 123.6 S / cm, respectively. Higher scan rates may limit the regular growth of the polymer; Example 5 showed a conductivity of only 2.3 S / cm at 50 mV / s, indicating that the scan rate has a significant regulatory effect on conductivity. By limiting the scan rate, the polymerization kinetics can be controlled, thereby affecting the microstructure and conductivity of PBFDO, providing adjustable process parameters for optimizing material properties.

[0019] Furthermore, the degree of polymerization is controlled by the number of cycles, affecting the molecular weight and packing density of the polymer. Ten cycles (as in Examples 1-4, 7-9) are sufficient to form a preliminary polymer network. Example 1 (10 cycles) showed a conductivity of 2.2 S / cm, and Example 6 (15 cycles) showed a conductivity of 123.6 S / cm, indicating that appropriately increasing the number of cycles is beneficial to improving conductivity. Fifty cycles (Example 5) provided more sufficient polymerization time, but the conductivity was only 2.3 S / cm, indicating that the number of cycles needs to be optimized in conjunction with other parameters, rather than simply increasing the number. By limiting the number of cycles to 10-50, this invention provides sufficient polymerization progress to ensure that the polymer can form and deposit, while avoiding side reactions caused by over-polymerization.

[0020] Furthermore, polar aprotic solvents can effectively dissolve BFDO monomers and supporting electrolytes, and possess a wide electrochemical stability window, making them suitable as electrochemical polymerization media. The high dielectric constant of polar aprotic solvents facilitates the dissociation of the supporting electrolyte, increases solution conductivity, and promotes the electrochemical polymerization reaction. In addition, BFDO monomers undergo enol tautomerism in polar aprotic solvents, which is a necessary prerequisite for their subsequent polymerization reaction.

[0021] Furthermore, by adjusting the electrolyte concentration, the ionic strength and double-layer structure of the solution can be controlled, affecting the polymerization rate and the degree of polymer doping. Example 1 (0.1 mol / L NH4Cl) showed a conductivity of 2.2 S / cm, Example 8 (0.4 mol / L NH4Cl) showed a conductivity of 428.3 S / cm, and Example 9 (0.6 mol / L NH4Cl) showed a conductivity of 258.5 S / cm, indicating that electrolyte concentration has a significant impact on conductivity. Lower concentrations (0.1 mol / L) may limit ion migration rates, while higher concentrations (0.6 mol / L) may affect the polymer doping state. The intermediate concentration of 0.4 mol / L achieved the optimal conductivity in Example 8.

[0022] Furthermore, the drying temperature affects the degree of removal of residual solvent in the polymer film, as well as the polymer chain arrangement and stacking state, thus affecting the final conductivity. The range of 60-100℃ covers the temperature of the solvent boiling point, ensuring effective solvent removal while avoiding polymer degradation that may be caused by excessively high temperatures.

[0023] This invention discloses a high-conductivity polybenzodifurandione (PBFDO), which is obtained by direct electrochemical polymerization with a conductivity as high as 428.3 S / cm. The resulting PBFDO is an n-type conductive polymer with a conductivity ranging from 2.2 to 428.3 S / cm, reaching 10 2 The S / cm efficiency is on the order of magnitude, verifying that this method can yield high-performance materials. SEM tests show that the high-conductivity PBFDO (such as in Example 8) has a dense rod-like structure, while the low-conductivity PBFDO (such as in Examples 1 and 5) exhibits a needle-like structure, demonstrating the correlation between microstructure and conductivity. Obtained via a green electrochemical pathway, without the need for catalysts or harsh conditions, this method solves the problems of difficult synthesis and poor performance of existing n-type conductive polymers, and has significant application value. Attached Figure Description

[0024] Figure 1 The images shown are SEM images of the surface of high-conductivity polybenzodifurandione disclosed in this invention; (A) is Example 1; (B) is Example 2; (C) is Example 3; (D) is Example 4; (E) is Example 5; (F) is Example 6; (G) is Example 7; (H) is Example 8; and (I) is Example 9. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0027] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0028] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0029] Unless otherwise specified, the components or preferred components involved in this invention can be combined with each other to form new technical solutions.

[0030] In this invention, unless otherwise specified, the numerical range "a~b" is an abbreviation for any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" indicates that the text already includes real numbers between "6~22", and "6~22" is simply an abbreviation for these numerical combinations.

[0031] The "scope" disclosed in this invention can be in the form of a lower limit and an upper limit, and can be one or more lower limits and one or more upper limits, respectively.

[0032] In this invention, the term "and / or" as used herein refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0033] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0034] This invention provides a cyclic voltammetric method for preparing high-conductivity polybenzodifurandione, comprising: BFDO monomer and supporting electrolyte were dissolved in a polar aprotic solvent to prepare an electrolyte solution. A three-electrode system was constructed using a platinum electrode immersed in the electrolyte as the working electrode and the counter electrode, and a saturated calomel electrode as the reference electrode. In an air atmosphere, cyclic voltammetry was applied to the counter electrode with a potential scan range of -3.5 to 3.5 V, a scan rate of 5 to 50 mV / s, and 10 to 50 cycles to carry out an electrochemical polymerization reaction, directly generating PBFDO polymer in the solution. After filtration and washing, the polymer was dried at 60 to 100 °C to obtain a PBFDO film. The conductivity of the n-type conductive polymer was 2.2 to 428.3 S / cm.

[0035] Among them, the polar aprotic solvents are dimethyl sulfoxide (DMSO), a mixed solution of dimethyl sulfoxide and N,N-dimethylformamide (DMF), or a mixed solution of dimethyl sulfoxide and acetonitrile (AN).

[0036] Supports any one of LiCl, NH4Cl and NaNO3 as the electrolyte.

[0037] The recommended electrolyte concentration in the electrolyte solution is 0.1-0.6 mol / L.

[0038] The concentration of BFDO monomer in the electrolyte is 8-20 mg / mL.

[0039] This invention successfully synthesized PBFDO electrochemically using cyclic voltammetry, completely eliminating the dependence on catalysts, high temperature and pressure, and oxygen-free environments required by traditional methods. It represents a green and low-cost synthetic route. Cyclic voltammetry can provide rich electrochemical signals in real time (such as changes in the intensity and position of redox peaks), enabling monitoring of the polymerization process and providing direct evidence for mechanism research and process optimization. By precisely adjusting parameters such as scan rate and cycle number, the kinetics of the polymerization reaction can be effectively controlled, thereby affecting the polymer morphology and final conductivity. The one-step synthesis and subsequent post-processing are simple, requiring no complex purification, and the resulting product is pure with high batch-to-batch consistency.

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0041] Example 1 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 20 mL of DMSO as solvent, add 0.107 g of NH4Cl and 0.160 g of BFDO monomer, and stir continuously until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -3V to 3V at a scan rate of 10mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 25 °C to constant weight, and finally the conductivity of the PBFDO polymer was tested using the four-probe method.

[0042] Example 2 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 15 mL of DMSO and 5 mL of AN as solvents, add 0.253 g of LiCl and 0.160 g of BFDO monomer, and continue stirring until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -3V to 3V at a scan rate of 10mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 60 °C to constant weight, and finally, the conductivity of the PBFDO polymer was tested using the four-probe method.

[0043] Example 3 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 15 mL of DMSO and 5 mL of AN as solvents, add 0.170 g of NaNO3 and 0.160 g of BFDO monomer, and stir continuously until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization. Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -3V to 3V at a scan rate of 10mV / s. Step 3: After the polymerization reaction is complete, the mixture is filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film is deposited on the surface of the filter paper, and the film surface is rinsed with a small amount of ethanol. The film is then dried at 100 °C to constant weight, and finally the conductivity of the PBFDO polymer is tested using the four-probe method.

[0044] Example 4 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 16 mL of DMSO and 4 mL of DMF as solvents, add 0.107 g of NH4Cl and 0.200 g of BFDO monomer, and continue stirring until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -3V to 3V at a scan rate of 5mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 80 °C to constant weight, and finally, the conductivity of the PBFDO polymer was tested using the four-probe method.

[0045] Example 5 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 12 mL of DMSO and 8 mL of DMF as solvents, add 0.253 g of LiCl and 0.400 g of BFDO monomer, and continue stirring until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 50 times within a potential window of 1.5V to 3.0V at a scan rate of 50mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 60 °C to constant weight, and finally, the conductivity of the PBFDO polymer was tested using the four-probe method.

[0046] Example 6 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 16 mL of DMSO and 4 mL of DMF as solvents, add 0.107 g of NH4Cl and 0.160 g of BFDO monomer, and stir continuously until the solid is completely dissolved, which is used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 15 times within a potential window of -3.0V to 3.0V at a scan rate of 5mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 80 °C to constant weight, and finally, the conductivity of the PBFDO polymer was tested using the four-probe method.

[0047] Example 7 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 13 mL of DMSO and 7 mL of DMF as solvents, add 0.107 g of NH4Cl and 0.160 g of BFDO monomer, and continue stirring until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -3.5V to 3.5V at a scan rate of 7 mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 80 °C to constant weight, and finally the conductivity of the PBFDO polymer was tested using the four-probe method.

[0048] Example 8 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 13 mL of DMSO and 7 mL of DMF as solvents, add 0.428 g of NH4Cl and 0.160 g of BFDO monomer, and stir continuously until the solid is completely dissolved, which is used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -3.0V to 3.0V at a scan rate of 5mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 80 °C to constant weight, and finally, the conductivity of the PBFDO polymer was tested using the four-probe method.

[0049] Example 9 A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione includes: Step 1: Measure 13 mL of DMSO and 7 mL of DMF as solvents, add 0.642 g of NH4Cl and 0.160 g of BFDO monomer, and continue stirring until the solid is completely dissolved, which will be used as the electrolyte for electrochemical polymerization; Step 2: A platinum sheet is used as the working electrode and counter electrode, and a saturated calomel electrode is used as the reference electrode. The three electrodes are inserted into the electrolyte and connected to an electrochemical workstation. Cyclic voltammetry is performed 10 times within a potential window of -2.0V to 2.0V at a scan rate of 5mV / s. Step 3: After the polymerization reaction was completed, the mixture was filtered using organic filter paper with a pore size of 20 μm. A PBFDO polymer film was deposited on the surface of the filter paper, and the film surface was rinsed with a small amount of ethanol. The film was then dried at 80 °C to constant weight, and finally, the conductivity of the PBFDO polymer was tested using the four-probe method.

[0050] Table 1. Conductivity test results of the high-conductivity polybenzodifurandione disclosed in Examples 1-9

[0051] Table 1 shows the conductivity test results of the high-conductivity polybenzodifurandione disclosed in Examples 1-9. As can be seen from the table, the polymers obtained after polymerization using NH4Cl as the supporting electrolyte and DMSO / DMF mixed solution as the solvent exhibit higher conductivity. Among Examples 1-5, only Example 4 has a conductivity close to 10. 2By adjusting the DMF and NH4Cl concentrations, it was found that when the DMSO:DMF ratio was 13:7, the conductivity increased to 171.7 S / cm. Increasing the DMF content promoted the polymerization reaction, but NH4Cl has poor solubility in DMF, and excessive DMF content would lead to electrolyte precipitation. Increasing the NH4Cl concentration to 0.4 mol / L increased the conductivity to 428.3 S / cm, but increasing it to 0.6 mol / L resulted in a decrease in conductivity. This is attributed to the difficulty in separating excess NH4Cl from the polymer, thus affecting the polymer's conductivity.

[0052] Figure 1 These are SEM images of the surface of the high-conductivity polybenzodifurandione disclosed in this invention; (A) is Example 1; (B) is Example 2; (C) is Example 3; (D) is Example 4; (E) is Example 5; (F) is Example 6; (G) is Example 7; (H) is Example 8; and (I) is Example 9. As can be seen from the figures, in Example 8 (H), the PBFDO polymerized by electrochemical methods exhibits high conductivity. Only the polymer surfaces in Examples 1 (A) and 5 (E) show needle-like structures, while the surfaces of the remaining polymers exhibit a more dense rod-like structure. Furthermore, the conductivity of Example 8 is 4 to 210 times that of the other examples. This invention is the first to successfully prepare polymers with conductivity exceeding 10 using cyclic voltammetry. 2 The S / cm PBFDO material provides a new approach for its green and efficient synthesis.

[0053] In summary, this invention provides a high-conductivity polybenzodifurandione and its cyclic voltammetric preparation method. In an air atmosphere, the benzodifurandione (BFDO) monomer is electrochemically oxidatively polymerized through multiple cycles of cyclic voltammetry, successfully growing a high-conductivity polybenzodifurandione (BFDO) on the electrode surface. 2 PBFDO with a strength on the order of S / cm effectively regulates the polymer growth process through unique periodic redox scanning, thereby achieving 10 2 This method achieves conductivity on the order of S / cm. It requires no catalysts or high-temperature, high-pressure conditions and allows real-time monitoring of the polymerization process via electrochemical signals. It not only provides a novel route for PBFDO preparation but also offers a new approach for the green and controllable synthesis of n-type conductive polymers through methodological innovation. This method successfully achieves catalyst-free polymerization of PBFDO under mild conditions (air atmosphere, room temperature and pressure). Furthermore, by utilizing the unique cyclic scanning mode of cyclic voltammetry, it enables real-time monitoring of the polymerization reaction. Through optimization of electrolyte composition and electrochemical parameters, it effectively controls the PBFDO growth process, resulting in polymers with dense structures and significantly improved conductivity.

[0054] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cyclic voltammetric method for preparing high-conductivity polybenzodifurandione, characterized in that, include: The benzodifurandione monomer and the supporting electrolyte were dissolved in a polar aprotic solvent to prepare an electrolyte solution. A three-electrode system is constructed by using a platinum electrode immersed in the electrolyte as the working electrode and the counter electrode, and a saturated calomel electrode as the reference electrode. In an air atmosphere, a cyclic voltammetric scan is applied to the working electrode to carry out an electrochemical polymerization reaction, directly generating polybenzodifurandione in the solution. After filtration, washing and drying, a high-conductivity polybenzodifurandione film is obtained. The high-conductivity polybenzodifurandione film is an n-type conductive polymer with a conductivity of 2.2~428.3 S / cm.

2. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The potential scan range of the cyclic voltammetric scan is -3.5 to 3.5 V.

3. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The scanning rate of the cyclic voltammetric scan is 5-50 mV / s.

4. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The cyclic voltammetric scan is performed 10-50 times.

5. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The polar aprotic solvent is dimethyl sulfoxide, a mixed solution of dimethyl sulfoxide and N,N-dimethylformamide, or a mixed solution of dimethyl sulfoxide and acetonitrile.

6. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The supporting electrolyte is any one of LiCl, NH4Cl, and NaNO3.

7. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The molar concentration of the supporting electrolyte in the electrolyte solution is 0.1-0.6 mol / L.

8. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The mass concentration of the benzodifurandione monomer in the electrolyte is 8-20 mg / mL.

9. The cyclic voltammetric method for preparing high-conductivity polybenzodifurandione according to claim 1, characterized in that, The drying temperature is 60-100℃.

10. A high-conductivity polybenzodifurandione, characterized in that, It was prepared by the cyclic voltammetric method for high conductivity polybenzodifurandione according to any one of claims 1-9.

Images