Conductive PEEK film and preparation method thereof

Abstract

The invention discloses a conductive PEEK film and a preparation method thereof, and belongs to the field of film materials. The invention relates to a conductive PEEK film, which is prepared from the following raw materials by weight: 88-97% of polyether-ether-ketone resin; 3-7% of a modified carbon nanotube; 0-5% of other auxiliary agents; the modified carbon nano tube is formed by coating a carbon nano tube with polyaniline and tannic acid. The conductive PEEK material has the advantages that the conductive capability of PEEK is effectively improved, and good mechanical properties are kept.

Description

Technical Field

[0001] The present application relates to the field of membrane materials, and in particular to a conductive PEEK film and a preparation method thereof. Background Art

[0002] Polyetheretherketone (PEEK) is a thermoplastic special engineering plastic. PEEK is a wholly aromatic polymer whose main chain is formed by benzene rings, ether groups and ketone groups interconnected. Since the benzene ring has a rigid structure and there are no active groups on the molecular chain, PEEK has excellent performance in thermal stability, wear resistance, flame retardancy and insulation. It can be used in military, aerospace, automotive, biomedicine and other fields.

[0003] PEEK's dimensional stability and light weight also make it suitable for use in areas such as liquid crystal display glass substrates and integrated circuit chip supports. However, this requires the material to have antistatic properties during high-temperature processing. As an insulating material, PEEK has poor conductivity, which greatly limits its application in the above-mentioned fields.

[0004] Currently, the conductivity of PEEK is enhanced by adding conductive fillers. However, conductive fillers have poor dispersibility in PEEK, which has limited effect on the enhancement of conductivity and affects the structural stability of PEEK, resulting in a decrease in the performance of PEEK itself. Summary of the Invention

[0005] In order to effectively improve the conductivity of PEEK, the present application provides a conductive PEEK film and a preparation method thereof.

[0006] In the first aspect, the present application provides a conductive PEEK film using the following technical solutions: A conductive PEEK film is prepared from raw materials comprising the following weight percentages: Polyetheretherketone resin 88-97%; Modified carbon nanotubes 3-7%; Other additives 0-5%; The modified carbon nanotubes are formed by coating carbon nanotubes with polyaniline and tannic acid.

[0007] By adopting the above technical solution, polyaniline is a conjugated polymer with conductive properties. After being coated on carbon nanotubes, it can synergistically improve the conductivity of PEEK. In addition, polyaniline and PEEK have similar benzene ring structures and good interface compatibility, which promotes the uniform dispersion of carbon nanotubes in PEEK to form a good conductive network. Combined with tannic acid coating of carbon nanotubes, the surface structure of carbon nanotubes is further modified, and the interfacial bonding strength between carbon nanotubes and PEEK is improved, thereby improving the conductivity of PEEK while maintaining the basic mechanical properties of PEEK.

[0008] Optionally, the polyaniline is prepared by polymerizing aniline on the surface of carbon nanotubes, and the mass ratio of the aniline, tannic acid and carbon nanotubes is (3-5):(0.8-1.2):1.

[0009] By adopting the above technical solution, the proportion of polyaniline and tannic acid on the surface of carbon nanotubes is adjusted, the modified structure of the surface of carbon nanotubes is adjusted, and the conductive properties of carbon nanotubes in PEEK are promoted.

[0010] Optionally, the tannic acid is cross-linked tannic acid, which is formed by reacting tannic acid with an aldehyde cross-linking agent, and the mass ratio of the tannic acid to the aldehyde cross-linking agent is 1:(0.03-0.08).

[0011] By adopting the above technical solution, a small amount of aldehyde cross-linking agent realizes pre-cross-linking of tannic acid, which helps the polymerization coating of polyaniline on the surface of carbon nanotubes, thereby further improving the conductivity of PEEK.

[0012] Optionally, the aldehyde cross-linking agent includes one or both of glyoxal and glutaraldehyde.

[0013] By adopting the above technical solution, glyoxal and glutaraldehyde help to form a slightly cross-linked structure of cross-linked tannic acid.

[0014] Optionally, the carbon nanotubes have a diameter of 10 to 20 nm, a length of 20 to 30 μm, and a specific surface area of ​​90 to 100 m 2 / g.

[0015] By adopting the above technical solution, the carbon nanotubes within the above parameter range can balance the dispersibility and conductivity in PEEK.

[0016] Optionally, the other auxiliary agents include one or both of ultraviolet absorbers and antioxidants.

[0017] In a second aspect, the present application provides a method for preparing a conductive PEEK film using the following technical solution: A method for preparing a conductive PEEK film comprises the following steps: Dispersing tannic acid, aniline and carbon nanotubes in water, adding an initiator while stirring under heating conditions, continuing the reaction for a period of time after the addition of the initiator, filtering and drying after the reaction to obtain modified carbon nanotubes; The polyetheretherketone resin is dissolved in a solvent, and after being uniformly dissolved, the modified carbon nanotubes and other additives are added, stirred and dispersed uniformly, degassed, coated on a substrate, dried to remove the solvent, and peeled off to obtain a conductive PEEK film.

[0018] By adopting the above technical solution, aniline is polymerized and coated on the surface of the carbon nanotubes, and tannic acid is also coated on the surface of the carbon nanotubes, thereby improving the surface structure of the carbon nanotubes.

[0019] Optionally, the carbon nanotubes are pre-treated with acid.

[0020] By adopting the above technical solution, the activity and contact area of ​​the surface of the acidified carbon nanotubes are improved, which is conducive to the coating of polyaniline and tannic acid.

[0021] Optionally, the tannic acid is cross-linked tannic acid, and the preparation method of the cross-linked tannic acid is as follows: dispersing the tannic acid in water, adding an aldehyde cross-linking agent while stirring, continuing the reaction for a period of time after adding the aldehyde cross-linking agent, adding a non-polar solvent after the reaction is completed, filtering, and drying to obtain the cross-linked tannic acid.

[0022] By adopting the above technical solution, mild cross-linking of tannic acid is achieved, and the cross-linked tannic acid is precipitated by a non-polar solvent.

[0023] In summary, this application has the following beneficial effects: 1. In the present application, carbon nanotube fillers are obtained by coating carbon nanotubes with polyaniline and tannic acid. Polyaniline is a conjugated polymer with conductive properties. After being coated on carbon nanotubes, it can synergistically improve the conductivity of PEEK. In addition, polyaniline and PEEK have similar benzene ring structures and good interface compatibility, which promotes the uniform dispersion of carbon nanotubes in PEEK to form a good conductive network. Combined with tannic acid coating of carbon nanotubes, the surface structure of carbon nanotubes is further modified, and the interfacial bonding strength between carbon nanotubes and PEEK is improved, thereby improving the conductivity of PEEK while maintaining the basic mechanical properties of PEEK.

[0024] 2. The present application preferably uses tannic acid for pre-crosslinking, which helps the polymerization and coating of polyaniline on the surface of carbon nanotubes, thereby further improving the conductivity of PEEK. DETAILED DESCRIPTION

[0025] The following is a further detailed description of this application.

[0026] Example 1 A conductive PEEK film is prepared from the following raw materials: 0.88kg polyetheretherketone resin, 0.07kg modified carbon nanotubes, 0.05kg ultraviolet absorber.

[0027] Among them, the polyetheretherketone resin comes from Zhongyan Polymer Brand 770.

[0028] The ultraviolet absorber is ultraviolet absorber uv234; Modified carbon nanotubes are made by coating carbon nanotubes with polyaniline and tannic acid. Polyaniline is formed by polymerizing aniline on the surface of carbon nanotubes. The diameter of carbon nanotubes is 10-20nm, the length is 20-30μm, and the specific surface area is 90-100m2 / g.

[0029] A method for preparing a conductive PEEK film comprises the following steps: The carbon nanotubes were dispersed in 98 wt % concentrated sulfuric acid and ultrasonically shaken in a water bath at 50° C. for 1 h, filtered, washed with water, and dried to complete the pretreatment of the carbon nanotubes.

[0030] 300 g of aniline, 80 g of tannic acid and 100 g of carbon nanotubes were dispersed in 10 L of water, heated to 60 ° C, and the initiator ammonium persulfate was added while stirring. The ammonium persulfate was pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water was 1:80. The amount of ammonium persulfate was 3 g. The initiator was added for 1 hour and the reaction was continued for 1.5 hours. After the reaction was completed, it was filtered, washed with water, and dried to obtain modified carbon nanotubes.

[0031] Polyetheretherketone resin was dissolved in 8L N,N-dimethylacetamide. After uniform dissolution, modified carbon nanotubes and ultraviolet absorber were added and stirred and dispersed uniformly for 30 minutes. Vacuum degassing was performed and the resulting slurry was coated on a release substrate and dried at 70°C for 24 hours to remove N,N-dimethylacetamide. The resulting film was soaked in dilute sulfuric acid and water for 24 hours respectively. After soaking, the film was peeled off to obtain a conductive PEEK film.

[0032] Example 2 A conductive PEEK film is prepared from the following raw materials: 0.97kg polyetheretherketone resin, 0.03kg modified carbon nanotubes.

[0033] Among them, the polyetheretherketone resin comes from Zhongyan Polymer Brand 770.

[0034] Modified carbon nanotubes are made by coating carbon nanotubes with polyaniline and tannic acid. Polyaniline is formed by polymerizing aniline on the surface of carbon nanotubes. The diameter of carbon nanotubes is 10-20nm, the length is 20-30μm, and the specific surface area is 90-100m 2 / g.

[0035] A method for preparing a conductive PEEK film comprises the following steps: The carbon nanotubes were dispersed in 98 wt % concentrated sulfuric acid and ultrasonically shaken in a water bath at 50° C. for 1 h, filtered, washed with water, and dried to complete the pretreatment of the carbon nanotubes.

[0036] 500g of aniline, 120g of tannic acid and 100g of carbon nanotubes were dispersed in 10L of water, heated to 50°C, and the initiator ammonium persulfate was added while stirring. The ammonium persulfate was pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water was 1:80. The amount of ammonium persulfate was 5g. The initiator was added for 1h and the reaction was continued for 2h. After the reaction was completed, it was filtered, washed with water, and dried to obtain modified carbon nanotubes.

[0037] Polyetheretherketone resin was dissolved in 10L N,N-dimethylacetamide. After uniform dissolution, modified carbon nanotubes and ultraviolet absorber were added and stirred and dispersed uniformly for 30 minutes. Vacuum degassing was performed and the resulting slurry was coated on a release substrate and dried at 70°C for 24 hours to remove N,N-dimethylacetamide. The resulting film was soaked in dilute sulfuric acid and water for 24 hours respectively. After soaking, the film was peeled off to obtain a conductive PEEK film.

[0038] Example 3 A conductive PEEK film is prepared from the following raw materials: 0.92kg polyetheretherketone resin, 0.06kg modified carbon nanotubes, 0.02kg ultraviolet absorber.

[0039] Among them, the polyetheretherketone resin comes from Zhongyan Polymer Brand 770.

[0040] The ultraviolet absorber is ultraviolet absorber uv234; Modified carbon nanotubes are made by coating carbon nanotubes with polyaniline and tannic acid. Polyaniline is formed by polymerizing aniline on the surface of carbon nanotubes. The diameter of carbon nanotubes is 10-20nm, the length is 20-30μm, and the specific surface area is 90-100m 2 / g.

[0041] A method for preparing a conductive PEEK film comprises the following steps: The carbon nanotubes were dispersed in 98 wt % concentrated sulfuric acid and ultrasonically shaken in a water bath at 50° C. for 1 h, filtered, washed with water, and dried to complete the pretreatment of the carbon nanotubes.

[0042] 400 g of aniline, 90 g of tannic acid and 100 g of carbon nanotubes were dispersed in 10 L of water, heated to 60 ° C, and the initiator ammonium persulfate was added while stirring. The ammonium persulfate was pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water was 1:80. The amount of ammonium persulfate was 3 g. The initiator was added for 1 hour and the reaction was continued for 1.5 hours. After the reaction was completed, it was filtered, washed with water, and dried to obtain modified carbon nanotubes.

[0043] Polyetheretherketone resin was dissolved in 9L N,N-dimethylacetamide. After uniform dissolution, modified carbon nanotubes and ultraviolet absorber were added and stirred and dispersed uniformly for 30 minutes. Vacuum degassing was performed and the resulting slurry was coated on a release substrate and dried at 70°C for 24 hours to remove N,N-dimethylacetamide. The resulting film was soaked in dilute sulfuric acid and water for 24 hours respectively. After soaking, the film was peeled off to obtain a conductive PEEK film.

[0044] Example 4 The difference between this embodiment and embodiment 1 is that the modified carbon nanotubes are formed by coating the carbon nanotubes with polyaniline and cross-linked tannic acid.

[0045] Preparation method of cross-linked tannic acid: Tannic acid was dispersed in water, and glyoxal was added while stirring. The mass ratio of tannic acid to aldehyde cross-linking agent was 1:0.03. After adding glyoxal, the reaction was continued for 1 hour. After the reaction was completed, chloroform was added. The precipitated solid was filtered, washed with water, and dried to obtain cross-linked tannic acid.

[0046] In the step of preparing modified carbon nanotubes, 300g of aniline, 80g of cross-linked tannic acid and 100g of carbon nanotubes are dispersed in 10L of water, heated to 60°C, and the initiator ammonium persulfate is added while stirring. The ammonium persulfate is pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water is 1:80. The amount of ammonium persulfate is 3g, the initiator is added for 1h, and the reaction is continued for 1.5h. After the reaction is completed, it is filtered, washed with water, and dried to obtain modified carbon nanotubes.

[0047] Example 5 The difference between this embodiment and embodiment 1 is that the modified carbon nanotubes are formed by coating the carbon nanotubes with polyaniline and cross-linked tannic acid.

[0048] Preparation method of cross-linked tannic acid: Tannic acid was dispersed in water, and glyoxal was added while stirring. The mass ratio of tannic acid to aldehyde cross-linking agent was 1:0.08. After the addition of glyoxal, the reaction was continued for 1 hour. After the reaction was completed, chloroform was added. The precipitated solid was filtered, washed with water, and dried to obtain cross-linked tannic acid.

[0049] In the step of preparing modified carbon nanotubes, 300g of aniline, 80g of cross-linked tannic acid and 100g of carbon nanotubes are dispersed in 10L of water, heated to 60°C, and the initiator ammonium persulfate is added while stirring. The ammonium persulfate is pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water is 1:80. The amount of ammonium persulfate is 3g, the initiator is added for 1h, and the reaction is continued for 1.5h. After the reaction is completed, it is filtered, washed with water, and dried to obtain modified carbon nanotubes.

[0050] Comparative Example 1 A conductive PEEK film is prepared from the following raw materials: 0.88kg polyetheretherketone resin, 0.07kg carbon nanotubes, 0.05kg ultraviolet absorber.

[0051] Among them, the polyetheretherketone resin comes from Zhongyan Polymer Brand 770.

[0052] The ultraviolet absorber is ultraviolet absorber uv234; The diameter of carbon nanotubes is 10-20nm, the length is 20-30μm, and the specific surface area is 90-100m 2 / g.

[0053] A method for preparing a conductive PEEK film comprises the following steps: Polyetheretherketone resin was dissolved in 8L N,N-dimethylacetamide. After uniform dissolution, carbon nanotubes and ultraviolet absorber were added and stirred and dispersed uniformly for 30 minutes. Vacuum degassing was performed and the resulting slurry was coated on a release substrate and dried at 70°C for 24 hours to remove N,N-dimethylacetamide. The resulting film was soaked in dilute sulfuric acid and water for 24 hours respectively. After soaking, the film was peeled off to obtain a conductive PEEK film.

[0054] Comparative Example 2 A conductive PEEK film is prepared from the following raw materials: 0.88kg polyetheretherketone resin, 0.04kg carbon nanotubes, 0.03kg polyaniline, 0.05kg ultraviolet absorber.

[0055] Among them, the polyetheretherketone resin comes from Zhongyan Polymer Brand 770.

[0056] The ultraviolet absorber is ultraviolet absorber uv234; The diameter of carbon nanotubes is 10-20nm, the length is 20-30μm, and the specific surface area is 90-100m 2 / g.

[0057] A method for preparing a conductive PEEK film comprises the following steps: Preparation method of polyaniline: 300 g of aniline was dispersed in 10 L of water, heated to 60 ° C, and the initiator ammonium persulfate was added while stirring. The ammonium persulfate was pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water was 1:80. The amount of ammonium persulfate was 3 g. The initiator was added for 1 hour and the reaction was continued for 1.5 hours. After the reaction was completed, it was filtered, washed with water, and dried to obtain polyaniline.

[0058] Polyetheretherketone resin and polyaniline were dissolved in 9L N,N-dimethylacetamide. After uniform dissolution, carbon nanotubes and ultraviolet absorber were added and stirred and dispersed uniformly for 30 minutes. Vacuum degassing was performed and the resulting slurry was coated on a release substrate and dried at 70°C for 24 hours to remove N,N-dimethylacetamide. The resulting film was soaked in dilute sulfuric acid and water for 24 hours respectively. After soaking, the film was peeled off to obtain a conductive PEEK film.

[0059] Comparative Example 3 A conductive PEEK film is prepared from the following raw materials: 0.88kg polyetheretherketone resin, 0.07kg modified carbon nanotubes, 0.05kg ultraviolet absorber.

[0060] Among them, the polyetheretherketone resin comes from Zhongyan Polymer Brand 770.

[0061] The ultraviolet absorber is ultraviolet absorber uv234; Modified carbon nanotubes are made by coating carbon nanotubes with polyaniline and cyclodextrin. Polyaniline is formed by polymerizing aniline on the surface of carbon nanotubes. The diameter of carbon nanotubes is 10-20nm, the length is 20-30μm, and the specific surface area is 90-100m 2 / g.

[0062] A method for preparing a conductive PEEK film comprises the following steps: The carbon nanotubes were dispersed in 98 wt % concentrated sulfuric acid and ultrasonically shaken in a water bath at 50° C. for 1 h, filtered, washed with water, and dried to complete the pretreatment of the carbon nanotubes.

[0063] 300g of aniline, 80g of cyclodextrin and 100g of carbon nanotubes were dispersed in 10L of water, heated to 60°C, and the initiator ammonium persulfate was added while stirring. The ammonium persulfate was pre-dissolved in water, and the mass ratio of ammonium persulfate to dissolving water was 1:80. The amount of ammonium persulfate was 3g. The initiator was added for 1h and the reaction was continued for 1.5h. After the reaction was completed, it was filtered, washed with water, and dried to obtain modified carbon nanotubes.

[0064] Polyetheretherketone resin was dissolved in 8L N,N-dimethylacetamide. After uniform dissolution, modified carbon nanotubes and ultraviolet absorber were added and stirred and dispersed uniformly for 30 minutes. Vacuum degassing was performed and the resulting slurry was coated on a release substrate and dried at 70°C for 24 hours to remove N,N-dimethylacetamide. The resulting film was soaked in dilute sulfuric acid and water for 24 hours respectively. After soaking, the film was peeled off to obtain a conductive PEEK film.

[0065] Performance Testing The following tests were performed on the conductive PEEK films prepared in Examples 1-5 and Comparative Examples 1-3.

[0066] With reference to GB / T 1040.3-2006 “Determination of tensile properties of plastics Part 3: Film and sheeting”, the tensile strength of the conductive PEEK film was tested.

[0067] With reference to GB / T 31838.3-2019 "Dielectric and resistive properties of solid insulating materials - Part 3: Resistance characteristics (DC method) - Surface resistance and surface resistivity", the surface resistance of the conductive PEEK film was tested.

[0068] The above test results are shown in Table 1.

[0069] Table 1 Tensile strength (MPa) Surface resistance (Ω) Example 1 94.6 <![CDATA[7.6×10 3 ]]> Example 2 95.0 <![CDATA[8.3×10 3 ]]> Example 3 94.1 <![CDATA[7.4×10 3 ]]> Example 4 95.8 <![CDATA[2.4×10 3 ]]> Example 5 95.6 <![CDATA[2.2×10 3 ]]> Comparative Example 1 88.3 <![CDATA[7.5×10 7 ]]> Comparative Example 2 86.5 <![CDATA[1.4×10 6 ]]> Comparative Example 3 92.6 <![CDATA[9.1×10 4 ]]> Combined with the above test results, it can be seen that compared with directly incorporating carbon nanotubes into polyetheretherketone resin to prepare a film, the present application first coats the carbon nanotubes with polyaniline and tannic acid, and then incorporates them into the polyetheretherketone resin. This can obtain a film with lower surface resistance and improved tensile strength, which is suitable for use scenarios with high conductivity requirements and high mechanical properties requirements.

[0070] Secondly, unlike polyaniline as a simple conductive polymer blended with polyetheretherketone resin, using polyaniline to coat carbon nanotubes effectively introduces polyaniline while improving the dispersion of carbon nanotubes, thereby improving the overall performance of the conductive PEEK film.

[0071] In addition, cross-linked tannic acid is preferably used to coat the carbon nanotubes, which helps to promote the polymerization and coating of polyaniline on the surface of the carbon nanotubes, thereby further improving the conductivity.

[0072] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A conductive PEEK film, characterized in that: It is prepared from the following raw materials in weight percentage: Polyetheretherketone resin 88~97%; Modified carbon nanotubes 3~7%; Other additives 0~5%; The modified carbon nanotubes are formed by coating carbon nanotubes with polyaniline and tannic acid.

2. The conductive PEEK film according to claim 1, characterized in that: The polyaniline is prepared by polymerizing aniline on the surface of carbon nanotubes, and the mass ratio of the aniline, tannic acid and carbon nanotubes is (3-5):(0.8-1.2):

1.

3. The conductive PEEK film according to claim 1, characterized in that: The tannic acid is cross-linked tannic acid, which is formed by reacting tannic acid with an aldehyde cross-linking agent. The mass ratio of the tannic acid to the aldehyde cross-linking agent is 1:(0.03-0.08).

4. The conductive PEEK film according to claim 3, characterized in that: The aldehyde cross-linking agent includes one or both of glyoxal and glutaraldehyde.

5. The conductive PEEK film according to claim 1, characterized in that: The carbon nanotubes have a diameter of 10-20 nm, a length of 20-30 μm, and a specific surface area of ​​90-100 m 2 / g.

6. The conductive PEEK film according to claim 1, characterized in that: The other auxiliary agents include one or both of ultraviolet absorbers and antioxidants.

7. A method for preparing a conductive PEEK film according to any one of claims 1 to 6, characterized in that: The following steps are involved: Dispersing tannic acid, aniline and carbon nanotubes in water, adding an initiator while stirring under heating conditions, continuing the reaction for a period of time after the addition of the initiator, filtering and drying after the reaction to obtain modified carbon nanotubes; The polyetheretherketone resin is dissolved in a solvent, and after being uniformly dissolved, the modified carbon nanotubes and other additives are added, stirred and dispersed uniformly, degassed, coated on a substrate, dried to remove the solvent, and peeled off to obtain a conductive PEEK film.

8. The method for preparing a conductive PEEK film according to claim 7, wherein: The carbon nanotubes are pre-treated with acid solution.

9. The method for preparing a conductive PEEK film according to claim 7, wherein: The tannic acid is cross-linked tannic acid. The preparation method of the cross-linked tannic acid comprises the following steps: dispersing the tannic acid in water, adding an aldehyde cross-linking agent while stirring, continuing the reaction for a period of time after the addition of the aldehyde cross-linking agent, adding a non-polar solvent after the reaction is completed, filtering, and drying to obtain the cross-linked tannic acid.