Method for preparing polymer conductive film doped with ionic liquid

Abstract

The present invention discloses a method for preparing a polymer conductive membrane doped with an ionic liquid, belonging to the field of polymer conductive membranes. The method for preparing a polymer conductive membrane doped with an ionic liquid of the present invention comprises the following steps: dissolving a polyolefin polyol in a solvent, then adding sulfuric acid to carry out a sulfonation reaction to obtain a sulfonated polyolefin polyol; mixing the sulfonated polyolefin polyol, aniline, and an oxidant in a solvent, reacting the mixture to obtain an aqueous conductive polymer dispersion; adding an ionic liquid to the aqueous conductive polymer dispersion, then adding the mixture to a mold, and heating and curing the mixture to obtain the polymer conductive membrane doped with an ionic liquid. The polymer conductive membrane doped with an ionic liquid prepared by the present invention has the advantages of low cost, good dispersibility, high stability, and excellent conductive properties.

Description

Technical Field

[0001] The present invention relates to the field of polymer conductive films, in particular to a method for preparing a polymer conductive film doped with an ionic liquid. Background Art

[0002] Conductive polymer materials can be attached to various substrates such as fibers, fabrics, and gels, and used to develop various devices such as flexible sensors, rechargeable batteries, electromagnetic interference shielding, electronic devices, display devices, and electrodes. Compared with other materials, they exhibit better flexibility, biocompatibility, and volume controllability, and have broad application prospects. In recent years, conductive polymer materials have been widely used to achieve the conversion of mechanical energy into electrical energy. Conductive polymer materials are divided into two categories: intrinsic conductive polymer materials and composite conductive polymer materials. Among them, intrinsic conductive polymer materials refer to polymers that can conduct electricity themselves, generally conjugated polymers such as polythiophene and polypyrrole. Composite conductive polymer materials refer to composite materials with conductive capabilities that are formed by incorporating conductive substances into polymer materials through methods such as dispersion composite, layer composite, gradient composite, and surface composite.

[0003] Among numerous conductive polymers, polyaniline (PAI) is widely used in research due to its numerous advantages, including its readily available and inexpensive raw materials, simple synthesis process, adjustable conductivity, good environmental stability, low percolation threshold, and melt processability. However, its practical application is significantly limited by the rigid structure and non-conductivity of its backbone, as well as its poor solubility due to the numerous hydrogen bonds within it.

[0004] Although polyaniline is a soluble polymer, dynamic light scattering experiments revealed that polyaniline has a strong tendency to aggregate its molecular chains in organic solvents. 4 ~10 6 g / mL) will exhibit the behavior of a single molecular chain. At normal concentrations, the polyaniline molecular chains tend to aggregate, and it is impossible to obtain a uniformly dispersed polyaniline dispersion with stable particle size. In addition, the added organic solvent easily evaporates into flammable gas, which has the risk of causing deflagration, explosion and fire. In addition, organic solvents have varying degrees of irritation to human skin, mucous membranes, etc., and some are carcinogenic and teratogenic. Further improvements are still needed in this regard.

[0005] In order to solve the problems of polyaniline such as insolubility, refractory melting, poor processability, and poor conductivity, doping modification is one of the research and development directions. Doping is one of the important modification methods for conductive polymer materials. Through doping, the conductive polymer chain can be equipped with electrons or holes with higher energy to form carriers, which can move in a direction in an external electric field. Acid doping modification of polyaniline includes two types: inorganic acid doping and organic acid doping. Among them, although inorganic acid doping can improve the working performance of polyaniline, the doped product obtained by this method has disadvantages such as poor environmental stability and easy dedoping. Although the method of organic acid doping can achieve higher product stability, the polyaniline prepared by it has uneven morphology, large particle size, relatively complicated preparation process, and usually high cost.

[0006] Therefore, there is an urgent need to develop a dopant and steric stabilizer for polyaniline that conforms to the concept of green development, has low cost, and a simple synthesis process, and to prepare a polyaniline conductive film with higher dispersibility, stability, conductivity, and is non-volatile and non-flammable through this dopant. Summary of the Invention

[0007] The present invention aims to provide a method for preparing a polymer conductive membrane doped with an ionic liquid to address the aforementioned problems in the background art. The present invention utilizes a sulfonated polyolefin polyol as a dopant, produces an aqueous polymer dispersion through in-situ polymerization, then dopes the dispersion with an ionic liquid and thermally cures it to form a polymer conductive membrane. The ionic liquid-doped polymer conductive membrane prepared by the present invention has the advantages of low cost, good dispersibility, high stability, and excellent conductive properties.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] One of the technical solutions of the present invention is to provide a method for preparing a polymer conductive film doped with an ionic liquid, comprising the following steps:

[0010] (1) dissolving the polyolefin polyol in a solvent, then adding sulfuric acid to carry out a sulfonation reaction to obtain a sulfonated polyolefin polyol;

[0011] (2) mixing the sulfonated polyolefin polyol, aniline, and an oxidant in a solvent and reacting them to obtain an aqueous conductive polymer dispersion;

[0012] (3) adding an ionic liquid to the aqueous conductive polymer dispersion, heating and curing the dispersion, and obtaining the ionic liquid-doped polymer conductive film.

[0013] Preferably, the polyolefin polyol is polyvinyl alcohol.

[0014] Preferably, in step (1), the mass ratio of the polyolefin polyol to sulfuric acid is 2-4:6.67-13.33; the temperature of the sulfonation reaction is 35-55° C., and the time is 0-1 h and is not 0.

[0015] Preferably, the oxidant is ammonium persulfate.

[0016] Preferably, in step (2): the molar ratio of the sulfonated polyolefin polyol to aniline is 2-4:0.67-1.33; the reaction is first carried out at 0-5°C for 4-6 hours, and then at 10-30°C for 10-14 hours.

[0017] Preferably, the ionic liquid is 1-ethyl-3-methylimidazolium hydrogen sulfate; the added amount of the ionic liquid is 1 to 5 wt% of the mass of the aqueous conductive polymer dispersion.

[0018] Preferably, in step (3): the temperature of the heating and curing is 40 to 60° C., and the time is 3 to 5 hours.

[0019] Preferably, the solvent is water.

[0020] The second technical solution of the present invention is to provide a polymer conductive film doped with ionic liquid obtained according to the above preparation method.

[0021] The beneficial technical effects of the present invention are as follows:

[0022] The present invention uses sulfonated polyolefin polyol as a dopant to produce a water-based polymer dispersion through in-situ polymerization. This dispersion is then doped with an ionic liquid and thermally cured to form a polymer conductive membrane. The ionic liquid-doped polymer conductive membrane produced by the present invention has the advantages of low cost, good dispersibility, high stability, and excellent conductive properties.

[0023] The sulfonated polyolefin polyol prepared by the present invention can be used as a dopant and steric stabilizer for polyaniline. It is water-soluble, has a simple synthesis process, and is low-cost. By co-doping the sulfonated polyolefin polyol and an ionic liquid into a conductive film, the resulting polymer conductive film exhibits high dispersibility, stability, and conductivity, making it suitable for use in flexible sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1This is a diagram of the color change of the solution during the in-situ polymerization process prepared in Example 1.

[0026] Figure 2 Graph showing the particle size distribution test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 1 to 3.

[0027] Figure 3 Graph showing the conductivity test results of the ionic liquid-doped polymer conductive membranes prepared in Examples 1 to 5 and Comparative Examples 1 to 3.

[0028] Figure 4 Graph showing the elongation at break test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 1 to 3.

[0029] Figure 5 Graph showing the sensitivity coefficient test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 2 to 3.

[0030] Figure 6 Schematic diagram of the microstructure of the ionic liquid-doped polymer conductive membrane prepared in Examples 1 to 5. DETAILED DESCRIPTION

[0031] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0032] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or stated range, and any other stated value or intervening value in the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.

[0034] The terms “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0035] Since the discovery of the conductivity of doped polyacetylene, conductive polymers have gradually gained attention. Doping is a key modification method for conductive polymers, primarily because they all possess a conjugated structure with alternating single and double bonds. However, in their intrinsic, undoped state, conductive polymers are virtually non-conductive, their electrons trapped in the valence band or conjugated π orbitals, unable to move in an external electric field. By doping polyaniline with organic protonic acids, the doped polyaniline can be dissolved or dispersed in common solvents, alleviating the processing difficulties of doped polyaniline.

[0036] There are two doping mechanisms for polyaniline, namely the charge transfer complex mechanism and the proton acid mechanism. The charge transfer complex mechanism believes that polyaniline, like most conductive polymers, will gain or lose electrons in the process of doping, and the dopant will be oxidized or reduced accordingly, eventually forming a product of the dopant ion and the conductive polymer chain. After doping, the conductivity will be greatly improved. The proton acid doping mechanism is a doping mechanism unique to polyaniline. It believes that in the process of doping, there is no gain or loss of electrons on the chain, and the H + First, it will enter the imine group, and the positive charge it carries will migrate along the polyaniline main chain and be distributed periodically, which will make the molecular chain positively charged. In order to maintain the overall electrical neutrality, the anion of the dopant will also be adsorbed around the polymer chain. Therefore, it can also be regarded as a salt-forming process.

[0037] The present invention provides a method for preparing a polymer conductive film doped with an ionic liquid, comprising the following steps:

[0038] (1) Dissolve 2-4 mmol of polyolefin polyol in a solvent at 70-90°C, then cool to 35-55°C, slowly add 33-66 wt% concentrated sulfuric acid solution, react for 0-1 hour, then wash several times, filter, and dry to obtain sulfonated polyolefin polyol. The synthetic route is shown in Formula 1:

[0039]

[0040] (2) Dissolving 2-4 mmol of the sulfonated polyolefin polyol in a solvent at 75-95° C., adding 0.67-1.33 mmol of aniline at 10-30° C., and adding 0.22-0.44 mmol of an oxidant dropwise at 0-5° C. for 4-6 hours, and then reacting at 10-30° C. for 10-14 hours to obtain a dark green aqueous conductive polymer dispersion. The synthetic route is shown in Formula 2:

[0041]

[0042] (3) adding an ionic liquid to the aqueous conductive polymer dispersion (the amount of the ionic liquid added is 1 to 5 wt% of the mass of the aqueous conductive polymer dispersion), stirring it at room temperature to fully dissolve and disperse it, then adding it to a mold, and then thermally curing it in an oven at 40 to 60° C. for 3 to 5 hours to obtain the polymer conductive film doped with the ionic liquid.

[0043] Preferably, the solvent is water.

[0044] The water-soluble conductive film prepared by the water-based processing method of the present invention uses water as a solvent, has the advantages of being environmentally friendly and non-toxic, does not have the problem of VOC emissions, and is in line with the concept of green development.

[0045] Preferably, the polyolefin polyol is polyvinyl alcohol 1788, with a molecular weight of 82,000 and a degree of alcoholysis of 85.0-90.0%.

[0046] Doping polyaniline with sulfonated polyvinyl alcohol (SPVA) generates hydrogen bonds and interactions between macromolecular chains, resulting in uniform dispersion of the polyaniline without aggregation, acting as a steric stabilizer. Furthermore, the partially sulfonated SPVA can further reduce the polyaniline particle size as a dopant. This doping scheme yields a conductive polyaniline dispersion with stable dispersion, excellent conductivity, and good water solubility.

[0047] Preferably, the oxidant is ammonium persulfate.

[0048] Ammonium persulfate provides oxidizing properties, promoting the in-situ polymerization of aniline monomer to form a water-based polyaniline dispersion. Ammonium persulfate decomposes under mild conditions to produce sulfate ion radicals, which possess an extremely high oxidation potential. Compared to other strong oxidants (such as potassium permanganate or hydrogen peroxide), ammonium persulfate works under milder pH and temperature conditions, avoiding the potential adverse effects of high-temperature and high-pressure operations.

[0049] Preferably, the ionic liquid is 1-ethyl-3-methylimidazolium hydrogen sulfate.

[0050] As ionic conductive media, ionic liquids offer advantages such as ease of use and convenient operation. By doping the conductive polymers of the present invention with ionic liquids, higher-energy electrons can be added to the conductive polymer chains, providing space for carrier formation. This results in ionic liquid-based conductive polymers with high conductivity, a wide electrochemical window, and low volatility and non-flammability.

[0051] Unless otherwise specified, the "room temperature" in the present invention is 10-30°C.

[0052] The polyvinyl alcohol used in the following examples and comparative examples of the present invention is polyvinyl alcohol 1788, which has a molecular weight of 82,000 and a degree of alcoholysis of 85.0-90.0%.

[0053] The raw materials used in the following examples and comparative examples of the present invention are all commercially available products.

[0054] Example 1

[0055] A method for preparing a polymer conductive film doped with an ionic liquid, comprising the following steps:

[0056] (1) Polyvinyl alcohol (6.000 g, 0.003 mol) was stirred and dissolved in deionized water (40.000 g, 2.220 mol) at 90°C. After the solution became clear and transparent, the temperature was lowered to 55°C. 40 mL of a 50 wt% concentrated sulfuric acid solution was slowly added dropwise. The solution was reacted for 0.5 h and then cooled to room temperature. The reaction solution was then precipitated and washed with anhydrous ethanol. The washing solution was filtered when the pH value was about 5 and dried in a vacuum drying oven until constant weight was obtained to obtain sulfonated polyvinyl alcohol (SPVA), which was then sealed and stored.

[0057] (2) Sulfonated polyvinyl alcohol (0.500 g, 2.220 mmol) was dissolved in deionized water (9.500 g). After the solution became clear and transparent, aniline (0.069 g, 0.740 mmol) was added at room temperature. At 4°C, ammonium persulfate (0.056 g, 0.247 mmol) dissolved in deionized water (1.000 g) was slowly added dropwise to the reaction solution. The reaction was continued for 5 h and then at room temperature for 12 h to obtain a dark green aqueous conductive polymer dispersion. The dispersion was sealed in a glass bottle and stored at room temperature.

[0058] (3) 10.00 g of the aqueous conductive polymer dispersion was placed in a sample bottle, 1-ethyl-3-methylimidazole hydrogen sulfate (the addition amount was 1 wt% of the mass of the aqueous conductive polymer dispersion) was added, and stirred at room temperature for 2 to 3 hours to allow the ionic liquid to be fully dissolved and dispersed in the aqueous conductive polymer dispersion. The mixture was then added to a mold and thermally cured in an oven at 60°C for 4 hours to obtain a polymer conductive film doped with an ionic liquid.

[0059] Example 2

[0060] The only difference from Example 1 is that the added amount of 1-ethyl-3-methylimidazolium hydrogen sulfate is modified to 2 wt % of the mass of the aqueous conductive polymer dispersion.

[0061] Example 3

[0062] The only difference from Example 1 is that the added amount of 1-ethyl-3-methylimidazolium hydrogen sulfate is modified to 3 wt % of the mass of the aqueous conductive polymer dispersion.

[0063] Example 4

[0064] The only difference from Example 1 is that the added amount of 1-ethyl-3-methylimidazolium hydrogen sulfate is modified to 4 wt % of the mass of the aqueous conductive polymer dispersion.

[0065] Example 5

[0066] The only difference from Example 1 is that the added amount of 1-ethyl-3-methylimidazolium hydrogen sulfate is modified to 5 wt % of the mass of the aqueous conductive polymer dispersion.

[0067] Figure 1 This is a diagram showing the color change of the solution during the in-situ polymerization of polyaniline during the preparation of Examples 1 to 5.

[0068] Figure 6 Schematic diagram of the microstructure of the ionic liquid-doped polymer conductive membrane prepared in Examples 1 to 5.

[0069] Comparative Example 1

[0070] The only difference from Example 1 is that 1-ethyl-3-methylimidazolium hydrogen sulfate is replaced by deionized water of equal mass.

[0071] Comparative Example 2

[0072] The only difference from Example 3 is that 1-ethyl-3-methylimidazolium hydrogen sulfate is changed to 1-ethyl-3-methylimidazolium tetrafluoroborate.

[0073] Comparative Example 3

[0074] The only difference from Example 3 is that 1-ethyl-3-methylimidazolium hydrogen sulfate is changed to 1-butyl-3-methylimidazolium tetrafluoroborate.

[0075] Comparative Example 4 (replaced with a macromolecular acid dopant commonly used in the art)

[0076] The only difference from Example 1 is that only step (2) is performed, and the SPVA in step (2) is replaced by equal masses of dodecylbenzenesulfonic acid, poly(2-acrylamide-2-methylpropanesulfonic acid), aminosulfonic acid, p-toluenesulfonic acid, and camphorsulfonic acid.

[0077] Effect verification

[0078] (1) Working performance tests were performed on Examples 1 to 5 and Comparative Examples 1 to 3.

[0079] Test conditions:

[0080] The conductivity of the polymer conductive films obtained in Examples 1 to 5 and Comparative Examples 1 to 3 was tested using a four-probe tester. The specific test method is as follows: first, the thickness of the conductive film is accurately measured using a film thickness meter. After turning on the instrument, the specification is first adjusted to "square resistance", and the thickness of the film is input. Then, the film is placed directly under the probe and the probe height is adjusted by rotating. The probe is inserted into the sample and the data is stabilized. Multiple readings are taken to calculate the average value. At the same time, measurements are taken at different positions of the sample to reduce errors. The results are shown in Tables 1 and Figure 3 shown.

[0081] The polymer conductive films of Examples 1 to 5 and Comparative Examples 1 to 3 were tested in accordance with GB / T1040-2006 "Determination of tensile properties of plastics". The specific test method is: select several samples of the same type with the same length and width, randomly select one of them, cut a 1mm wide notch in the middle of the sample, and then perform tensile tests on the notched and intact samples respectively to reflect the relationship between stress and strain. The test results are shown in Tables 1 and Figure 4 As shown. The fracture energy is calculated according to formula 1:

[0082]

[0083] In formula 1: w, the toughness of the notched sample at the same elongation as the intact sample at the maximum tensile strength (MJ / m 3 ), c, notch width (mm); λc, elongation at break of notched sample.

[0084] The strain sensing properties of the polymer conductive films of Examples 1 to 5 and Comparative Examples 2 to 3 were tested using an electrochemical workstation. The specific operation was as follows: first, conductive copper tape was wrapped around both ends of the sample and clamped with the clamps at both ends of the wire on the workstation. A constant voltage was applied to the sample to stretch it, and a curve of current versus time was obtained. The rate of change of the sample resistance was obtained according to Ohm's law. The test results are shown in Tables 1 and Figure 5 As shown. GF is a parameter used to measure the sensitivity of the sensor. GF is usually expressed as the ratio of the output electrical signal to the applied external force. Among them, the sensitivity coefficient GF is calculated according to formula 2:

[0085]

[0086] Where: R0 is the resistance before strain (Ω); ΔR is the change in resistance with strain (Ω); and ε is the strain caused by the external force, that is, the ratio of the length change ΔL to the initial length L0.

[0087] The particle size distribution of the polymer conductive films of Examples 1 to 5 and Comparative Examples 1 to 3 was tested. The specific operation was as follows: the particle size of the prepared liquid sample was tested and analyzed using a 90plus PALS laser particle size analyzer produced by Bruker, Germany. First, a small amount of the sample to be tested was weighed with a dropper and dropped into a container specifically used for testing. The sample was then diluted by adding deionized water several times until it became clear and transparent. The test was repeated three times to avoid accidental experimental errors, thereby obtaining a particle size distribution curve and an average particle size of the sample to be tested. The test results are shown in FIG. Figure 2 shown.

[0088] Test results:

[0089] Table 1 Conductivity, mechanical properties and sensitivity coefficients of polymer electrolytes

[0090]

[0091] In the field of flexible sensors, the elastic modulus of the material needs to be close to the modulus of human skin (0-1 MPa), and the lower the modulus, the better, while keeping other properties unchanged. As can be seen from the data recorded in Table 1, the elastic moduli of Examples 1 and 2 are relatively too high, and although the elastic moduli of Examples 4 and 5 are appropriate, the sensitivity is too low. Overall, the sensitivity coefficient of Example 3 is the best and the mechanical properties also meet the requirements.

[0092] As can be seen from Table 1, compared with comparative examples 1 to 3, the products of Examples 1 to 5 have excellent working performance. It can be seen that the ionic liquid with the greatest impact on the conductive film is the conductive film prepared in Example 3 with a content of 3 wt% of 1-ethyl-3-methylimidazolium hydrogen sulfate, whose conductivity is as high as 1.1692 mS / mm, elongation at break is 437.65%, and sensitivity coefficient is 2.55. When other conditions remain unchanged and only the content of the ionic liquid is changed, the conductivity of the conductive film prepared shows a trend of first increasing and then decreasing with the increase of the ionic liquid content. When the ionic liquid content is 4 wt%, the conductivity reaches 1.53 mS / mm and then decreases again. However, it can be seen that the addition of this ionic liquid significantly improves the conductivity of the polyaniline conductive film. This is mainly because this type of ionic liquid can provide a large number of carriers while having a co-doping effect on polyaniline, thus significantly improving the conductivity of the conductive film. However, when a certain content is reached, it will cause the polyaniline doping in the system to be oversaturated, resulting in partial dedoping of the polyaniline, thereby reducing the conductivity.

[0093] As can be seen from Table 1, the elongation at break of Examples 1 to 5 shows a trend of first increasing, then decreasing, and then increasing again as the content of 1-ethyl-3-methylimidazolium hydrogen sulfate increases. This is mainly because the rigid imidazole rings on the ionic liquid form intermolecular interactions with the polymer chains in the system. Initially, as the ionic liquid content continues to increase, the number of rigid imidazole rings increases, leading to an increase in both the elongation at break and the tensile strength. As the content continues to increase, the ionic liquid monomer acts as a diluent in the system, causing the elongation at break of the conductive film to decrease. Therefore, the appropriate addition of ionic liquid is beneficial to enhancing the electrostatic interaction in the network, thereby increasing the internal forces of the system, while excessive ionic liquid will destroy the uniformity of the network.

[0094] As can be seen from Table 1, the overall trend of the sensitivity coefficients of Examples 1 to 5 is to increase first, then decrease, and then increase again. This is mainly because the increase in the ionic liquid content in the early stage will increase the number of conductive channels inside the conductive membrane, so the rate of change of resistance caused by deformation will also increase, that is, the sensitivity coefficient will also increase; when the ionic liquid content continues to increase, a certain deformation (referring to the deformation caused by the increase in the conductive channels inside the conductive membrane caused by the increase in the ionic liquid content) will not cause a large change in resistivity. In summary, this is consistent with the previous laws of conductivity and mechanical properties. Since the spline prepared in Comparative Example 1 can only be stretched and cannot rebound, its sensitivity coefficient cannot be calculated.

[0095] Figure 2 Graph showing the particle size distribution test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 1 to 3.

[0096] Figure 3 Graph showing the conductivity test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 1 to 3.

[0097] Figure 4 Graph showing the elongation at break test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 1 to 3.

[0098] Figure 5 This is a graph showing the sensitivity coefficient test results of the ionic liquid-doped polymer conductive films prepared in Examples 1 to 5 and Comparative Examples 2 to 3.

[0099] (2) The performance of the aqueous polyaniline dispersion prepared in Example 1 was compared with that of Comparative Example 4. The average particle size of the polyaniline was measured, and the cost of the dopant was compared. The test results are shown in Table 2.

[0100] Table 2 Particle size and cost analysis of polyaniline doped with different dopants

[0101]

[0102] As shown in Table 2, compared with other commonly used macromolecular acid dopants in the art, the product obtained by using SPVA as a dopant for polyaniline has the smallest particle size and the lowest cost.

[0103] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a polymer conductive film doped with an ionic liquid, characterized in that: The following steps are involved: (1) dissolving the polyolefin polyol in a solvent, then adding sulfuric acid to carry out a sulfonation reaction to obtain a sulfonated polyolefin polyol; (2) mixing the sulfonated polyolefin polyol, aniline, and an oxidant in a solvent and reacting them to obtain an aqueous conductive polymer dispersion; (3) adding an ionic liquid to the aqueous conductive polymer dispersion, heating and curing, and obtaining the polymer conductive film doped with the ionic liquid; The polyolefin polyol is polyvinyl alcohol; The ionic liquid is 1-ethyl-3-methylimidazolium hydrogen sulfate; the addition amount of the ionic liquid is 1 to 5 wt% of the mass of the aqueous conductive polymer dispersion.

2. The preparation method according to claim 1, characterized in that In step (1), the mass ratio of the polyolefin polyol to sulfuric acid is 2-4:6.67-13.33; the temperature of the sulfonation reaction is 35-55° C., and the time is 0-1 h and is not 0.

3. The preparation method according to claim 1, characterized in that The oxidant is ammonium persulfate.

4. The preparation method according to claim 1, characterized in that In step (2), the molar ratio of the sulfonated polyolefin polyol to aniline is 2-4:0.67-1.33; the reaction is first carried out at 0-5°C for 4-6 hours, and then at 10-30°C for 10-14 hours.

5. The preparation method according to claim 1, characterized in that In step (3): the temperature of the heating and curing is 40 to 60° C., and the time is 3 to 5 hours.

6. The preparation method according to claim 1, characterized in that The solvent is water.

7. A polymer conductive film doped with an ionic liquid obtained according to the preparation method according to any one of claims 1 to 6.

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