Carbon nanotube / polyaniline composite modified epoxy resin conductive coating and preparation method thereof

Abstract

The application discloses a kind of carbon nanotube / polyaniline composite modified epoxy resin conductive paint and preparation method thereof, belong to coating technical field.The application is prepared by preliminary disentangling carbon nanotube with specific solvent, and the carbon nanotube dispersion liquid uniformly dispersed is obtained;Afterwards, polyaniline is added to carbon nanotube dispersion liquid, and carbon nanotube / polyaniline composite is prepared by solvent evaporation or purification;Finally, carbon nanotube / polyaniline composite is compounded with epoxy resin, and high-performance carbon nanotube / polyaniline composite modified epoxy resin conductive paint is obtained.The carbon nanotube / polyaniline composite modified epoxy resin conductive paint prepared by the application has more excellent mechanical properties and electrical properties than traditional conductive paint, and can be better applied in aerospace, battery, communication, new energy and other aspects.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of carbon nanotube / polyaniline composite modified epoxy resin conductive paint and its preparation method, belong to the field of coating technology. BACKGROUND

[0002] Conductive paint plays an important role in preventing static electricity accumulation and electrostatic discharge (ESD), and epoxy resin as a matrix material provides excellent adhesion, chemical resistance and mechanical strength, forming a hard protective coating. Carbon nanotubes as conductive fillers added to epoxy resin can significantly improve the conductivity of the paint. Carbon nanotubes with their excellent conductivity and high strength, a small amount of addition can effectively reduce the surface resistance of the coating, enhance the wear resistance and mechanical strength of the coating.

[0003] When epoxy resin and carbon nanotubes are used in conductive paint, although its performance potential is huge, it faces a series of challenges. First, the dispersion problem of carbon nanotubes significantly affects the uniformity and conductivity of the paint, and is prone to aggregation; ensuring good dispersion of conductive fillers in epoxy resin is key, effective dispersion technology and surface treatment method need to be used. Secondly, the compatibility problem between epoxy resin and conductive fillers cannot be ignored; if the interface is not well combined, the physical properties and conductivity of the coating will be affected. Therefore, it is necessary to enhance the interaction between the reinforcing materials. In addition, carbon nanotubes can improve the conductivity of the paint, but how to balance its proportion to achieve the best performance is still a challenge; excessive use may lead to a decrease in the mechanical properties of the coating, and insufficient cannot achieve the expected conductive effect.

[0004] Currently, the methods commonly used for carbon nanotubes in epoxy resin systems include solution blending, in-situ polymerization, chemical modification, etc.; for example: the document (Shi X J, Ren Y D. Thermal and mechanical properties of carbon nanotube / epoxy resin composites [J]. Journal of Pingdingshan University, 2020, 35(5): 39-42.) adopts solution blending method, which is to add carbon nanotubes into ethanol, ultrasonic dispersion stirring, then add epoxy resin into the suspension, and then magnetic stirring. When the temperature rises to 60℃, the ethanol in the system is removed by vacuum distillation, and the carbon nanotube / epoxy resin composite material is obtained; the document (Yao M J. Carbon nanotube polyacrylic acid functionalization and application in epoxy resin [D]: [Master's Degree Thesis]. Ocean University of China, 2014.) adopts in-situ polymerization method, which is to use in-situ polymerization method-polymerization to functionalize carbon nanotubes with polyacrylic acid, and prepare carbon nanotube / epoxy resin composite material; the document (Gao R Z. Preparation and mechanical properties of functionalized carbon nanotube / continuous carbon fiber multiscale reinforced epoxy resin composite material [D]: [Master's Degree Thesis]. Beijing University of Chemical Technology, 2021.) is to prepare a mixed acid solution with a ratio of concentrated sulfuric acid and concentrated nitric acid of 1:1, add a certain amount of carbon nanotubes to the prepared mixed acid solution, and stir gently with a glass rod until the stirring is uniform. Heat the mixed solution to reflux to fully oxidize the multi-walled carbon nanotubes, and obtain carboxylated carbon nanotubes; the carboxylated carbon nanotubes and epoxy resin are compounded to prepare carboxylated carbon nanotube / epoxy resin composite material; but in these methods, carbon nanotubes are difficult to disperse uniformly in the epoxy resin system, and cannot effectively transfer the load on the matrix to the carbon nanotubes, making it difficult to fully exert the excellent performance of carbon nanotubes; and, it is difficult to mass-produce in industry; in addition, the improvement of the mechanical properties, electrical conductivity and other properties of epoxy resin is limited.

[0005] In addition, the dispersion difficulty of carbon nanotubes and conventional graphene, graphene oxide in the epoxy resin system is different. The dispersion of graphene oxide is easier because its surface contains more active groups. Graphene is a sheet structure, and its dispersion considers the stacking between the sheets. However, carbon nanotubes are prone to aggregation and entanglement due to their nanometer effect, resulting in uneven dispersion at high content.

[0006] In summary, although epoxy resin and carbon nanotube composites have broad application prospects in conductive coatings, challenges such as dispersion, compatibility, conductivity control, processing technology, and environmental stability need to be addressed to promote their development in practical applications. SUMMARY

[0007] [TECHNICAL PROBLEM]

[0008] Carbon nanotubes have problems of difficult dispersion in epoxy resin systems, limited improvement of electrical and mechanical properties, and inability to mass production.

[0009] The dispersion method of carbon nanotubes will damage the structure of carbon nanotubes to some extent, resulting in reduced electrical conductivity; and the carbon nanotubes have poor compatibility with epoxy resin.

[0010] [Technical scheme]

[0011] To solve the above problems, the present application provides a kind of carbon nanotube / polyaniline composite modified epoxy resin conductive coating and its preparation method. Specifically, the present application prepares a uniformly dispersed carbon nanotube dispersion liquid by initially untangling carbon nanotubes with a specific solvent; then polyaniline is added to the carbon nanotube dispersion liquid, and a carbon nanotube / polyaniline composite is prepared after solvent evaporation or purification; finally, the carbon nanotube / polyaniline composite is combined with epoxy resin to obtain a high-performance carbon nanotube / polyaniline composite modified epoxy resin conductive coating. The present application utilizes the efficient and orderly nanometer assembly between carbon nanotubes and polyaniline in a specific solvent, which not only compensates for the defect of carbon nanotubes CNT that tend to aggregate into bundles, but also solves the dispersion problem of carbon nanotubes CNT in epoxy resin, while enhancing the mechanical and electrical properties of epoxy resin. The carbon nanotube / polyaniline composite modified epoxy resin conductive coating prepared by the present application has more excellent mechanical and electrical properties than traditional conductive coatings, and can be better applied in aerospace, batteries, communications, new energy and other fields.

[0012] The first object of the present application is to provide a method for preparing a carbon nanotube / polyaniline composite modified epoxy resin conductive coating, comprising the following steps:

[0013] (1) uniformly mix carbon nanotubes and a solvent to obtain a uniformly dispersed carbon nanotube dispersion liquid;

[0014] wherein the solvent is one or more of m-cresol, o-cresol, p-cresol, and resorcinol; or a mixture of one or more of the above solvents and one or more of n-hexane, 1,4-dioxane, toluene, anisole, and chloroform;

[0015] (2) add polyaniline to the carbon nanotube dispersion liquid, mix uniformly, and evaporate or purify the solvent to obtain a carbon nanotube / polyaniline composite;

[0016] (3) add the carbon nanotube / polyaniline composite to the epoxy resin, mix uniformly to obtain a mixture; add a curing agent to the mixture, mix uniformly to obtain a carbon nanotube / polyaniline composite modified epoxy resin conductive coating.

[0017] In one embodiment of the present application, the carbon nanotubes in step (1) are multi-walled carbon nanotubes with an average diameter of 7-11 nm and a length of 5-20 μm.

[0018] In one embodiment of the present application, the mass concentration of the carbon nanotubes in the carbon nanotube dispersion of step (1) is 0.1-2%.

[0019] In one embodiment of the present application, the mixing in step (1) is ultrasonic mixing, which is performed at 30-60 W and 400-800 rpm for 30-60 min.

[0020] In one embodiment of the present application, the mass ratio of polyaniline to the carbon nanotubes in step (2) is 10:(1-10), and further preferably 10:(1-5).

[0021] In one embodiment of the present application, the mixing in step (2) is ultrasonic mixing, which is performed at 30-60 W and 400-800 rpm for 30-60 min.

[0022] In one embodiment of the present application, the solvent purification in step (2) is performed by adding a low dielectric constant solvent, which is added in an amount of (0.1-1):1 by volume to the carbon nanotube dispersion; and the low dielectric constant solvent is one of acetone, ethanol, methanol and butanone.

[0023] In one embodiment of the present application, the polyaniline is added in step (2) while an auxiliary dispersant is simultaneously added, and the mass ratio of the auxiliary dispersant to the polyaniline is 1-5:10.

[0024] The auxiliary dispersant is a phenolic hydroxyl dispersant; further, the phenolic hydroxyl dispersant is one or more of tannic acid, cardanol and dopamine.

[0025] In one embodiment of the present application, the mass concentration of the carbon nanotube / polyaniline composite in the epoxy resin conductive coating of step (3) is 0.1-5 wt%.

[0026] In one embodiment of the present application, the mixing in step (3) is performed at 15-40°C (room temperature) and 300-600 rpm for 5-40 min.

[0027] In one embodiment of the present application, the curing agent in step (3) is an epoxy curing agent.

[0028] In one embodiment of the present application, the mass ratio of the curing agent to the epoxy resin in step (3) is 0.1-0.5:1.

[0029] The second object of the present application is the carbon nanotube / polyaniline composite modified epoxy resin conductive coating prepared by the method of the present application.

[0030] The third object of the present application is to provide a conductive composite material using the carbon nanotube / polyaniline composite modified epoxy resin conductive coating of the present application.

[0031] In one embodiment of the present application, the substrate of the conductive composite material is one of plastic, fiber and fabric.

[0032] In one embodiment of the present application, the conductive composite material is obtained by coating the carbon nanotube / polyaniline composite modified epoxy resin conductive coating of the present application on the surface of the substrate and drying.

[0033] In one embodiment of the present application, the film formed by the coating is peeled off from the substrate after drying to obtain the conductive composite material.

[0034] The fourth object of the present application is the application of the carbon nanotube / polyaniline composite modified epoxy resin conductive coating and the conductive composite material of the present application in the fields of aerospace, battery, communication and new energy.

[0035] The fifth object of the present application is to provide a battery using the carbon nanotube / polyaniline composite modified epoxy resin conductive coating and the conductive composite material of the present application.

[0036] The sixth object of the present application is to provide a method for improving the dispersibility, stability and conductivity of carbon nanotubes in epoxy resin, comprising the following steps:

[0037] (1) mixing the carbon nanotubes and the solvent uniformly to obtain a uniformly dispersed carbon nanotube dispersion liquid;

[0038] wherein the solvent is one or more of m-cresol, o-cresol, p-cresol and resorcinol; or a mixture of one or more of the above solvents and one or more of n-hexane, 1,4-dioxane, toluene, anisole and chloroform;

[0039] (2) adding polyaniline into the carbon nanotube dispersion liquid and mixing uniformly, and evaporating the solvent or purifying to obtain a carbon nanotube / polyaniline composite;

[0040] (3) adding the carbon nanotube / polyaniline composite into the epoxy resin and mixing uniformly to obtain a mixture; adding a curing agent into the mixture and mixing uniformly to obtain a carbon nanotube / polyaniline composite modified epoxy resin conductive coating.

[0041] [Advantages]

[0042] (1) The present application adopts specific solvent to disperse carbon nanotubes, greatly reduces the time and power of ultrasonic, avoids destroying the structure of carbon nanotubes and weakening the performance of carbon nanotubes; and makes the carbon nanotube / polyaniline composite modified epoxy resin conductive coating exhibit excellent conductive performance.

[0043] (2) The present application uses polyaniline to further improve the dispersion performance of carbon nanotubes in specific solvents, improve the compatibility of carbon nanotubes and epoxy resin, reduce the agglomeration of carbon nanotubes, and improve the interfacial interaction force.

[0044] (3) The present application adopts a process of using specific solvents to preliminarily untangle and purify carbon nanotubes, and the prepared carbon nanotube / polyaniline slurry is suitable for a solvent-free system, avoiding environmental pollution caused by solvent volatilization. At the same time, due to the need for purification, the specific solvent used can be recycled to some extent, improving the utilization rate of resources.

[0045] (4) The carbon nanotube / polyaniline composite prepared by the present application has good dispersibility, and also has good compatibility with other oily resins, and can be compounded with resins to prepare stable conductive coatings.

[0046] (5) The carbon nanotube / polyaniline composite modified epoxy resin conductive coating prepared by the present application exhibits excellent conductive performance and mechanical properties, and has wide application prospects in the fields of new energy, aerospace, communication, etc. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 (a) FT-IR diagram, (b) Raman spectrum of CNT, PANI, CNT / PANI in Example 1.

[0048] Figure 2 (a) and (b) are thermogravimetric analysis diagrams of CNT, PANI, CNT / PANI in Example 1 and different PANI addition amounts in Example 2.

[0049] Figure 3 (a) 0.5% EP / CNT, (b) 0.5% EP / Original CNT, (c) 0.5% EP / (CNT-PANI=10-1), (d) 0.5% EP / (CNT-PANI=10-2), (e) Local enlarged view of d, (f) Local enlarged view of c, (g) 0.5% EP / (CNT-PANI=10-3), (h) 0.5% EP / (CNT-PANI=10-4), (i) 0.5% EP / (CNT-PANI=10-5) are cross-sectional SEM diagrams of composite films. DETAILED DESCRIPTION

[0050] The following describes preferred embodiments of the present application, and it should be understood that the embodiments are for better explaining the present application and are not intended to limit the present application.

[0051] Test method:

[0052] 1. Infrared test:

[0053] A Fourier transform infrared spectrometer (Nicolet iS50) produced by Thermo Fisher Corporation of the United States was used to test whether the preparation of carbon nanotube / polyaniline was successful.

[0054] 2. Thermogravimetric test:

[0055] A Mettler-Toledo thermogravimetric analyzer (TGA2) produced by Mettler-Toledo Corporation of Switzerland was used to test the adsorption amount of polyaniline in carbon nanotube / polyaniline.

[0056] 3. Raman test:

[0057] A microconfocal Raman spectrometer (inVia) produced by Renishaw Corporation of the United Kingdom was used to test the interaction force between carbon nanotube / polyaniline.

[0058] 4. SEM test

[0059] A field emission electron scanning microscope (S-4800) produced by Hitachi Corporation of Japan was used to perform morphological characterization on the cross section of the composite film.

[0060] 5. Resistance:

[0061] A multimeter was used for testing.

[0062] 6. Mechanical property test

[0063] A universal testing machine (5967X) produced by Instron Corporation of the United States was used to test the mechanical properties of the composite film. The sample bar was dumbbell-shaped, with a length of 20 mm, a width of 4 mm, and a thickness of 0.4 mm.

[0064] Raw materials used in the examples:

[0065] Multi-walled carbon nanotubes: average diameter 7-11 nm, carbon tube length 5-20 μm, purchased from Jiangsu Tainai Technology Co., Ltd. (FT7320 CNT);

[0066] Polyaniline powder: particle size 5-8 μm, sulfonic acid doping, conductive state, purity > 98%, purchased from Sigma-Aldrich;

[0067] Epoxy resin: Tian Sheng Technology Co., Ltd., TTC-518-3AWJ22C131;

[0068] Epoxy curing agent: Taisheng Technology Co., Ltd., TTC-518-3AWJ22C141;

[0069] M-cresol: 99.5%;

[0070] The reaction temperature not specifically indicated in the examples is at room temperature (25°C).

[0071] Example 1

[0072] A method for preparing a carbon nanotube / polyaniline composite modified epoxy resin conductive coating, comprising the following steps:

[0073] (1) 0.15 g of multi-walled carbon nanotubes (CNT) and 30 g of m-cresol were mixed and ultrasonically mixed in a water bath at 40 W, 600 rpm for 60 min to obtain a uniformly dispersed carbon nanotube dispersion; wherein the mass concentration of carbon nanotubes in the carbon nanotube dispersion was 0.5%;

[0074] (2) 0.03 g of polyaniline (PANI) was added to the carbon nanotube dispersion and ultrasonically mixed in a water bath at 40 W, 600 rpm for 10 min, and then acetone was added to make the composite settle, thereby preparing a carbon nanotube / polyaniline composite; wherein the volume ratio of acetone to carbon nanotube dispersion was 0.5:1;

[0075] (3) 0.5 g of carbon nanotube / polyaniline composite was added to 100 g of epoxy resin (EP) and stirred at 500 rpm for 30 min to obtain a mixture; 50 g of epoxy curing agent was added to the mixture and stirred at 500 rpm for 10 min to obtain a carbon nanotube / polyaniline composite modified epoxy resin conductive coating, labeled as 0.5% EP / (CNT-PANI=10-2).

[0076] Example 2

[0077] The mass of polyaniline (PANI) in step (2) of Example 1 was adjusted to 0.015 g, 0.045 g, 0.06 g, and 0.075 g, respectively, and the other conditions were the same as in Example 1, thereby obtaining epoxy resin conductive coatings, labeled as 0.5% EP / (CNT-PANI=10-1), 0.5% EP / (CNT-PANI=10-3), 0.5% EP / (CNT-PANI=10-4), and 0.5% EP / (CNT-PANI=10-5).

[0078] Example 3

[0079] The addition amount of the carbon nanotube / polyaniline composite in step (3) of Example 1 was adjusted to 0.1 g, 1.0 g, and 1.5 g, and the other conditions were the same as in Example 1 to obtain an epoxy conductive coating, which was marked as 0.1% EP / (CNT-PANI=10-2), 1.0% EP / (CNT-PANI=10-2), and 1.5% EP / (CNT-PANI=10-2).

[0080] Comparative Example 1

[0081] The carbon nanotube / polyaniline composite in step (3) of Example 1 was omitted, and the other conditions were the same as in Example 1 to obtain a coating, which was marked as EP.

[0082] Comparative Example 2

[0083] The carbon nanotube / polyaniline composite in step (3) of Example 1 was replaced by multi-walled carbon nanotubes, and the other conditions were the same as in Example 1 to obtain a coating, which was marked as 0.5% EP / Original CNT.

[0084] Comparative Example 3

[0085] The carbon nanotube / polyaniline composite in step (3) of Example 1 was replaced by a multi-walled carbon nanotube slurry, and the other conditions were the same as in Example 1 to obtain a coating, which was marked as 0.5% EP / CNT.

[0086] The preparation method of the multi-walled carbon nanotube slurry is as follows:

[0087] 0.15 g of multi-walled carbon nanotubes (CNT) and 30 g of m-cresol were mixed under water bath ultrasonic mixing at 40 W and 600 rpm for 60 min to obtain a uniformly dispersed carbon nanotube dispersion; wherein the mass concentration of the carbon nanotubes in the carbon nanotube dispersion was 0.5%.

[0088] Acetone was added to make the composite settle, and a carbon nanotube slurry was prepared; wherein the volume ratio of acetone to the carbon nanotube dispersion was 0.5:1.

[0089] Example 4

[0090] A conductive composite material was prepared using the coatings obtained in Examples 1-3 and Comparative Examples 1-3.

[0091] Specifically;

[0092] The coatings obtained in Examples 1-3 and Comparative Examples 1-3 were scraped onto a PET film (thickness 40 μm) using a 750 μm four-sided scraper, and dried in a 100°C oven for 60 min. The film formed by the coating was then peeled off from the PET film to obtain a conductive composite material.

[0093] The obtained conductive composite material is subjected to performance test, and the test results are as follows:

[0094] Figure 1 The (a) FT-IR diagram and (b) Raman spectrum of CNT, PANI and CNT / PANI in Example 1 are shown in Figures 1 and 2. Figure 1 As can be seen from (a) in Figure 1, some characteristic peaks that CNT never has appear in CNT / PANI compared with CNT, which are 1307 cm -1 , 1480 cm -1 and 1575 cm -1 corresponding to the stretching vibration of C-N, C=C and C=N respectively. These newly appearing peaks are the characteristic infrared peaks of PANI. Figure 1 As can be seen from (b) in Figure 2, 1156 cm -1 in PANI moves to 1166 cm -1 in CNT / PANI, which indicates that the interaction between the quinone ring on PANI and the carbon ring on CNT in CNT / PANI is very significant, and the preparation of PANI modified CNT is successful.

[0095] Figure 2 The (a) thermogravimetric analysis diagram of CNT, PANI and CNT / PANI in Example 1 and the (b) thermogravimetric analysis diagram of different PANI addition amounts in Example 2 are shown in Figures 3 and 4. Figure 2 As can be seen from (a) in Figure 3, the thermogravimetric curve of CNT / PANI has a significant pyrolysis weight loss phenomenon at 300-500℃, which is the same as the pyrolysis weight loss of PANI, and again proves from the side that PANI is adsorbed on CNT, and CNT / PANI is successfully prepared. Under different PANI addition amounts, the actual real adsorption amount of PANI is determined by the thermogravimetric curve in (b) in Figure 4. Figure 2 After being heated to 800℃, the residues of CNT, CNT / PANI (10 / 1), CNT / PANI (10 / 2), CNT / PANI (10 / 3), CNT / PANI (10 / 4), CNT / PANI (10 / 5) are 96.0%, 93.2%, 89.8%, 85.9%, 83.4%, 80.9% respectively. According to the residual amount of PANI, it can be seen that the actual adsorption amount of PANI is far less than the addition amount, and the actual adsorption amount is about 3%, 7%, 10%, 13%, 16% according to the addition amount.

[0096] Figure 3Cross-section SEM images of composite films of (a) 0.5% EP / CNT, (b) 0.5% EP / Original CNT, (c) 0.5% EP / (CNT-PANI=10-1), (d) 0.5% EP / (CNT-PANI=10-2), (e) a local enlarged view of (d), (f) a local enlarged view of (c), (g) 0.5% EP / (CNT-PANI=10-3), (h) 0.5% EP / (CNT-PANI=10-4), (i) 0.5% EP / (CNT-PANI=10-5). To observe the dispersion degree and interface effect of CNT / PANI in the two-component epoxy resin matrix. From Figure 3 It can be seen that: compared with 0.5% EP / CNT and 0.5% EP / Original CNT, the original CNT is not dispersed, and the agglomeration phenomenon is more obvious, and the agglomeration area is larger. When the addition amount of CNT is kept at 0.5%, different amounts of PANI are added, and as the amount of PANI increases, the dispersion effect of CNT in the EP matrix is obviously improved. When the addition amount of PANI is 10% of CNT, there is still a small amount of CNT agglomeration phenomenon, but the agglomeration phenomenon is obviously weakened. As the addition amount of PANI increases, to 20%, the agglomeration phenomenon of CNT in the matrix completely disappears, the dispersion of CNT in the matrix is greatly improved, the CNT is completely coated by PANI, and the cross-section of the composite film is relatively smooth, which indicates that the compatibility between CNT and EP under high PANI ratio is good.

[0097] Table 1 mechanical property test results

[0098]

[0099] Table 2 conductive property test

[0100]

[0101]

[0102] Note: "-" represents that the resistance is very large and does not have conductive properties.

[0103] Example 5

[0104] In Example 1 step (1), the intermediate m-cresol is a mixed solvent of 1,4-dioxane and m-cresol with a volume ratio of 1:4; other conditions are the same as Example 1, and a conductive coating is obtained.

[0105] Example 6

[0106] In Example 1 step (1), the intermediate m-cresol is a mixed solvent of 1,4-dioxane and m-cresol with a volume ratio of 1:4; other conditions are the same as Example 1, and a conductive coating is obtained.

[0107] Example 7

[0108] Adjusting the acetone in step (2) of Example 1 to ethanol; other and Example 1 remain the same, to obtain a conductive coating.

[0109] Comparative Example 4

[0110] Adjusting the polyaniline in Example 1 to polyvinylpyrrolidone; other and Example 1 remain the same, to obtain a conductive coating.

[0111] Comparative Example 5

[0112] Adjusting the polyaniline in Example 1 to gallic acid; other and Example 1 remain the same, to obtain a conductive coating.

[0113] Comparative Example 6

[0114] Adjusting the acetone in step (2) of Example 1 to a mass fraction of 4% NaOH aqueous solution; other and Example 1 remain the same, to obtain a conductive coating.

[0115] Comparative Example 7

[0116] Adjusting the acetone in step (2) of Example 1 to N-methylpyrrolidone (NMP); other and Example 1 remain the same, to obtain a conductive coating.

[0117] Example 8

[0118] A conductive composite material using the coating obtained from Examples 5-7 and Comparative Examples 4-7;

[0119] Specifically;

[0120] The coating obtained from Examples 5-7 and Comparative Examples 4-7 is scraped onto a PET film (thickness 40 μm) using a 750 μm four-sided scraper, dried in a 100°C oven for 60 min, and then the film formed by the coating is peeled off from the PET film to obtain a conductive composite material.

[0121] The obtained conductive composite material is tested for performance, and the test results are as follows:

[0122] Table 3 Test results of Examples 5-7

[0123] Example Tensile strength (MPa) Elongation at break (%) Surface resistance (Ω) / sq Example 5 44.81±0.5 8.24±0.7 4.7 x 10 7 ]]> Example 6 46.54±0.6 8.85±0.5 8.8 x 10 6 ]] Example 7 42.36±0.5 6.74±0.5 6.8 x 10 6 ]]

[0124] Table 4 Test results of Comparative Examples 4-7

[0125] Example Surface resistance (Ω) / sq Comparative Example 4 10 8 ]] Comparative Example 5 10 8 ]] Comparative Example 6 10 9 ]] Comparative Example 7 5.2 x 10 7 ]]>

[0126] Comparative Example 8

[0127] A method for preparing an epoxy resin conductive coating, comprising the following steps:

[0128] (1) 0.15 g multi-walled carbon nanotubes (CNT), 0.03 g polyaniline (PANI) and 30 g m-cresol were mixed to obtain a uniformly dispersed mixture by water bath ultrasonic mixing at 40 W and 600 rpm for 60 min;

[0129] (2) The mixture was allowed to settle by adding acetone to prepare a carbon nanotube / polyaniline composite; wherein the volume ratio of acetone to the mixture was 0.5:1;

[0130] (3) 0.5 g of the carbon nanotube / polyaniline composite was added to 100 g of epoxy resin (EP) and stirred at 500 rpm for 30 min to obtain a mixture; 50 g of an epoxy curing agent was added to the mixture and stirred at 500 rpm for 10 min to obtain an epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification.

[0131] It was found that:

[0132] The multi-walled carbon nanotubes (CNT) were severely agglomerated and could not form a uniform system at all.

[0133] Comparative Example 9

[0134] A method for preparing an epoxy resin conductive coating, comprising the following steps:

[0135] (1) 0.03 g polyaniline (PANI) and 30 g m-cresol were mixed to obtain a uniformly dispersed polyaniline dispersion by water bath ultrasonic mixing at 40 W and 600 rpm for 60 min;

[0136] (2) 0.15 g multi-walled carbon nanotubes (CNT) was added to the polyaniline dispersion and mixed by water bath ultrasonic mixing at 40 W and 600 rpm for 10 min; the mixture was allowed to settle by adding acetone to prepare a carbon nanotube / polyaniline composite; wherein the volume ratio of acetone to the polyaniline dispersion was 0.5:1;

[0137] (3) 0.5 g of the carbon nanotube / polyaniline composite was added to 100 g of epoxy resin (EP) and stirred at 500 rpm for 30 min to obtain a mixture; 50 g of an epoxy curing agent was added to the mixture and stirred at 500 rpm for 10 min to obtain an epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification.

[0138] It was found that:

[0139] The multi-walled carbon nanotubes (CNT) were severely agglomerated and could not form a uniform system at all.

[0140] Example 8

[0141] A method for preparing a carbon nanotube / polyaniline composite modified epoxy resin conductive coating, comprising the following steps:

[0142] (1) 0.15 g of multi-walled carbon nanotubes (CNT) and 30 g of m-cresol are mixed and ultrasonically mixed in a water bath at 40 W and 600 rpm for 60 min to obtain a uniformly dispersed carbon nanotube dispersion liquid; wherein the mass concentration of carbon nanotubes in the carbon nanotube dispersion liquid is 0.5%;

[0143] (2) 0.03 g of polyaniline (PANI) and 0.01 g of tannic acid are added to the carbon nanotube dispersion liquid, and ultrasonically mixed in a water bath at 40 W and 600 rpm for 10 min, and then acetone is added to make the composite settle, to obtain a carbon nanotube / polyaniline composite; wherein the volume ratio of acetone to carbon nanotube dispersion liquid is 0.5:1;

[0144] (3) 0.5 g of the carbon nanotube / polyaniline composite is added to 100 g of an epoxy resin (EP), and stirred at 500 rpm for 30 min to obtain a mixture; 50 g of an epoxy curing agent is added to the mixture, and stirred at 500 rpm for 10 min to obtain a carbon nanotube / polyaniline composite modified epoxy resin conductive coating.

[0145] Example 9

[0146] A method for preparing a carbon nanotube / polyaniline composite modified epoxy resin conductive coating, comprising the following steps:

[0147] (1) 0.15 g of multi-walled carbon nanotubes (CNT) and 30 g of m-cresol are mixed and ultrasonically mixed in a water bath at 40 W and 600 rpm for 60 min to obtain a uniformly dispersed carbon nanotube dispersion liquid; wherein the mass concentration of carbon nanotubes in the carbon nanotube dispersion liquid is 0.5%;

[0148] (2) 0.03 g of polyaniline (PANI) and 0.01 g of tannic acid are added to the carbon nanotube dispersion liquid, and ultrasonically mixed in a water bath at 40 W and 600 rpm for 10 min, and then acetone is added to make the composite settle, to obtain a carbon nanotube / polyaniline composite; wherein the volume ratio of acetone to carbon nanotube dispersion liquid is 0.5:1;

[0149] (3) 0.5 g of the carbon nanotube / polyaniline composite is added to 100 g of an epoxy resin (EP), and stirred at 500 rpm for 30 min to obtain a mixture; 50 g of an epoxy curing agent is added to the mixture, and stirred at 500 rpm for 10 min to obtain a carbon nanotube / polyaniline composite modified epoxy resin conductive coating.

[0150] The obtained epoxy resin conductive coating is subjected to performance testing, and the specific testing method is as follows:

[0151] The coating obtained from Examples 8, 9 was scraped on a PET film (thickness 40 μm) using a four-sided coater with a 750 μm doctor blade, dried in an oven at 100°C for 60 min, and then the film of coating was peeled off from the PET film to obtain a conductive composite.

[0152] The test results of the conductive composites are as follows:

[0153] Table 5 Test results of Examples 8, 9

[0154] Example Tensile strength (MPa) Elongation at break (%) Surface resistance (Ω) / sq Example 8 48.36±0.8 11.84±0.4 5.8 x 10 6 ]] Example 9 49.50±0.6 12.44±0.5 4.6 x 10 6 ]]>

[0155] Although the present application has been disclosed with reference to preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present application, and the scope of protection of the present application should be defined by the claims.

Claims

1. A method for preparing an epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification, characterized in that, Includes the following steps: (1) Mix carbon nanotubes and solvent evenly to obtain a uniformly dispersed carbon nanotube dispersion; The solvent is one or more of m-cresol, o-cresol, p-cresol, and resorcinol; or a mixture of the above solvent with one or more of n-hexane, 1,4-dioxane, toluene, anisole, and chloroform. (2) Add polyaniline to the carbon nanotube dispersion, mix evenly, and add one of acetone, ethanol, methanol, or butanone to cause the composite to settle, thus obtaining a carbon nanotube / polyaniline composite. (3) Add the carbon nanotube / polyaniline composite to the epoxy resin and mix evenly to obtain a mixture; add a curing agent to the mixture and mix evenly to obtain a conductive epoxy resin coating based on carbon nanotube / polyaniline composite modification; In step (1), the mass ratio of carbon nanotubes to polyaniline in step (2) is 10:1, 10:2, 10:3, 10:4 or 10:

5.

2. The method according to claim 1, characterized in that, The mass concentration of carbon nanotubes in the carbon nanotube dispersion in step (1) is 0.1-2%.

3. The method according to claim 1, characterized in that, The mass concentration of the carbon nanotube / polyaniline composite in the epoxy resin conductive coating of step (3) is 0.1-5 wt%.

4. The method according to claim 1, characterized in that, When polyaniline is added in step (2), an auxiliary dispersant is also added at the same time. The auxiliary dispersant is a phenolic hydroxyl dispersant.

5. The epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification prepared by the method according to any one of claims 1-4.

6. A conductive composite material, characterized in that, The epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification as described in claim 5 was adopted.

7. The application of the epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification as described in claim 5 and the conductive composite material as described in claim 6 in the fields of aerospace, batteries, communications and new energy.

8. A battery, characterized in that, The epoxy resin conductive coating based on carbon nanotube / polyaniline composite modification as described in claim 5 and the conductive composite material as described in claim 6 are used.

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