Polyetherimide / polyaryletherketone composite material with high breakdown performance and mechanical toughness as well as preparation method and application of polyetherimide / polyaryletherketone composite material

Abstract

The invention discloses a polyetherimide / polyaryletherketone composite material with high breakdown performance and mechanical toughness as well as a preparation method and application of the polyetherimide / polyaryletherketone composite material, and belongs to the technical field of polyetherimide insulation. The invention solves the problems that the dielectric constant of the polyetherimide can be improved by increasing the use amount of the conductive filler in the prior art, but the breakdown performance of the polyetherimide is reduced, so that the polyetherimide cannot have toughness and high breakdown performance at the same time. According to the invention, polyetherimide and polyaryletherketone are used as raw materials and are mixed by adopting a solution blending method, then a substrate is coated with the mixture, and the polyaryletherketone / polyetherimide / polyaryletherketone composite material is obtained through curing. According to the invention, polyetherimide and polyaryletherketone are well dispersed on a microscopic scale, and the composite material has low dielectric loss of polyetherimide and high toughness of PAEK, and has good dielectric properties and breakdown electrical strength; the material is suitable for the advanced fields of high-energy density capacitors, power electronic devices, aerospace electrical insulation parts, new energy automobile high-voltage systems and the like.

Description

Technical Field

[0001] This invention relates to the field of polyetherimide insulation technology, specifically to a polyetherimide / polyaryletherketone composite material that combines high breakdown performance and mechanical toughness, its preparation method, and its application. Background Technology

[0002] With the continuous development of modern electronic devices and power system technologies, the demand for high-performance dielectric materials is increasing. Polymer-based dielectric materials, due to their excellent dielectric properties, processability, and mechanical properties, show broad application prospects in high-energy-density capacitors, power electronic devices, and flexible electronic products. Polyetherimide (PEI), as a thermoplastic engineering plastic, possesses excellent thermal stability, mechanical strength, and electrical insulation properties. Its glass transition temperature is as high as 200°C or more, allowing it to maintain good insulation and structural stability even at high temperatures. Furthermore, PEI has a low dielectric constant and dielectric loss, making it suitable as an insulating material for high-frequency, high-speed electronic devices. However, PEI itself is relatively brittle and lacks sufficient impact resistance and flexibility, which to some extent limits its application in flexible electronics and high-frequency power systems.

[0003] Currently, conductive fillers or other materials are typically introduced into PEI materials to form composites, aiming to improve the toughness and breakdown performance of PEI. However, the resulting composites cannot meet the demands of current applications in terms of improved toughness and breakdown performance. Some composites even exhibit problems such as increased dielectric loss and decreased dielectric strength under high-frequency electric fields, which may be related to interfacial polarization, insufficient compatibility, and microstructural inhomogeneity. Moreover, the toughness of the resulting composites may be lower than that of pure PEI. Furthermore, under high-filling or high-temperature environments, the conductivity of the composites may increase, thereby affecting their electrical insulation properties. Therefore, existing PEI cannot simultaneously possess both high toughness and high breakdown performance. Summary of the Invention

[0004] To address the technical problem in the prior art where adding fillers to increase the dielectric constant of polyetherimide results in polyetherimide not possessing both toughness and high breakdown performance, this invention provides a polyetherimide / polyaryletherketone composite material that balances high breakdown performance and mechanical toughness, along with its preparation method and applications.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: One of the objectives of this invention is to provide a polyetherimide / polyaryletherketone composite material that combines high breakdown performance with mechanical toughness. This composite material is made by mixing polyetherimide and polyaryletherketone as raw materials using a solution blending method, then coating them onto a substrate and curing them. Further specified, the content of polyaryletherketone in the polyetherimide / polyaryletherketone composite material is 0.1 ~ 0.9 wt.

[0006] A second objective of this invention is to provide a method for preparing the above-mentioned polyetherimide / polyaryletherketone composite material, the method comprising the following steps: Step 1: Preparation of polyetherimide / polyaryletherketone composite solution: Polyetherimide was added to N-methylpyrrolidone, and polyaryletherketone was added under stirring to obtain a mixed system. The mixed system was heated and stirred until the polyetherimide and polyaryletherketone were fully dissolved to obtain a polyetherimide / polyaryletherketone composite solution. Step 2: Preparation of polyetherimide / polyaryletherketone composite material; The polyetherimide / polyaryletherketone composite solution obtained in step one is degassed under vacuum, then coated onto a pretreated substrate and cured to form a thin film. The thin film on the substrate is then peeled off to obtain the polyetherimide / polyaryletherketone composite material.

[0007] Further specifying, in step one, the mass-to-volume ratio of polyetherimide to solvent is 2 g: 8 mL.

[0008] Further specifying, in step one, the mass-to-volume ratio of polyarylether ketone to solvent is (0.002~0.018) g: 8 mL.

[0009] Further specify that the heating temperature in step one is 60~80 ℃ and the heating and stirring time is 8~12 h.

[0010] Further specifying, the vacuum condition parameters in step two are: vacuuming time 10~12 h.

[0011] Further specifying the pretreatment process in step two, the substrate is first washed with clean water 1 to 3 times, then wiped clean with lint-free paper, then washed with anhydrous ethanol 3 to 5 times, and finally dried at 50 to 60 ℃ for 1 to 2 hours to obtain the pretreated substrate.

[0012] Furthermore, the substrate is a high-temperature resistant glass plate.

[0013] Further specifying, the curing temperature in step two is 80~85 ℃, and the time is 11~12 h.

[0014] Further specifying, in step two, after curing, the substrate is first immersed in water at 20~50 ℃ for 30 min, and then the film is peeled off.

[0015] The fourth objective of this invention is to provide an application of the above-mentioned polyetherimide / polyaryletherketone composite material in dielectric capacitors.

[0016] The present invention has the following beneficial effects: (1) In this invention, polyetherimide (PEI) and polyaryletherketone (PAEK) are dissolved in the highly polar solvent N-methylpyrrolidone. The mixture is stirred thoroughly at a high temperature to ensure complete dissolution of both polymers. Subsequently, the two polymers are mixed using a solution blending method to form a homogeneous composite system. By optimizing the blending ratio of PEI and PAEK and the processing technology, PEI and PAEK are well dispersed at the microscale, resulting in a higher dielectric constant and significantly improved breakdown strength of the polyetherimide / polyaryletherketone composite material compared to pure PEI and pure PAEK. This enhances the insulation performance of PEI material under high electric field conditions.

[0017] (2) This invention introduces PAEK into PEI. PAEK has high breakdown strength, high tensile strength and good ductility. The polyetherimide / polyaryletherketone composite material prepared by the two not only has the low dielectric loss of PEI and the high toughness of PAEK, but also has good dielectric properties and breakdown strength. Moreover, due to the high breakdown strength of PAEK, the breakdown performance of the composite material is further improved, making it suitable for advanced fields such as high energy density capacitors, power electronic devices, aerospace electrical insulation components and high voltage systems for new energy vehicles.

[0018] (3) The preparation process of the present invention is simple and controllable, suitable for solution processing, mature and low cost, and suitable for large-scale industrial production. Attached Figure Description

[0019] Figure 1 The image is a scanning electron microscope image of the polyetherimide film without polyaryletherketone in Comparative Example 1. Figure 2 Scanning electron microscope (SEM) image of the polyetherimide / polyaryletherketone composite material prepared in Example 3; Figure 3 The diagram shows the DC breakdown Weibull distribution of pure polyetherimide and the polyetherimide / polyaryletherketone composite material of the present invention. ■ represents pure polyetherimide, ● represents a polyaryletherketone mass fraction of 0.1%, ▲ represents a polyaryletherketone mass fraction of 0.3%, ▼ represents a polyaryletherketone mass fraction of 0.5%, and ◆ represents a polyaryletherketone mass fraction of 0.7%. This indicates that the mass fraction of polyaryletherketone is 0.9%; Figure 4 The dielectric constant test results are for pure polyetherimide and the polyetherimide / polyaryletherketone composite material of the present invention. ■ indicates pure polyetherimide, ● indicates a polyaryletherketone mass fraction of 0.1%, ▲ indicates a polyaryletherketone mass fraction of 0.3%, ▼ indicates a polyaryletherketone mass fraction of 0.5%, and ◆ indicates a polyaryletherketone mass fraction of 0.7%. This indicates that the mass fraction of polyaryletherketone is 0.9%; Figure 5 The results are strain-stress test results for pure polyetherimide and the polyetherimide / polyaryletherketone composite material of the present invention. A represents pure polyetherimide, B represents a polyaryletherketone mass fraction of 0.1%, C represents a polyaryletherketone mass fraction of 0.3%, D represents a polyaryletherketone mass fraction of 0.5%, E represents a polyaryletherketone mass fraction of 0.7%, and F represents a polyaryletherketone mass fraction of 0.9%. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0023] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art. Specific implementation method one: This embodiment describes a polyetherimide / polyaryletherketone composite material, which is prepared according to the following steps: Step 1: Preparation of polyetherimide / polyaryletherketone composite solution: Polyetherimide was added to a highly polar solvent, stirred, and then polyaryletherketone was added to obtain a mixed system. The mixed system was heated and stirred until the polyetherimide and polyaryletherketone were fully dissolved to obtain a polyetherimide / polyaryletherketone composite solution. Step 2: Preparation of polyetherimide / polyaryletherketone composite material; The polyetherimide / polyaryletherketone composite solution obtained in step one is degassed under vacuum and then coated onto a pretreated substrate for curing to form a thin film. The thin film on the substrate is then peeled off to obtain the polyetherimide / polyaryletherketone composite material, in which the polyaryletherketone content is 0.1~0.9 wt%. Specific Implementation Method Two: The difference between this embodiment and Specific Embodiment 1 is that the heating temperature in step one is 60~80 ℃, while the other steps are the same as in Specific Embodiment 1. Specific implementation method three: The difference between this embodiment and specific embodiment one or two is that the heating and stirring time in step one is 8~12 hours, while the other steps are the same as in specific embodiment one or two. Specific implementation method four: The difference between this embodiment and one of the specific embodiments one to three is that the mass-volume ratio of polyarylether ketone to solvent in step one is (0.002~0.018) g: 8 mL, while the other steps are the same as those in specific embodiments one to three. Specific implementation method five: The difference between this embodiment and one of the specific embodiments one to four is that the vacuuming time in step two is 10 to 12 hours; the pretreatment process is as follows: first, the substrate is washed with clean water 1 to 3 times, then wiped clean with lint-free paper, then washed with anhydrous ethanol 3 to 5 times, and finally dried at 50 to 60 °C for 1 to 2 hours to obtain the pretreated substrate. The substrate is a high-temperature resistant glass plate. Other steps are the same as those in specific embodiments one to four. Specific implementation method six: The difference between this embodiment and one of the specific embodiments one to five is that the curing temperature in step two is 80~85℃ and the curing time is 11~12 h, while the other steps are the same as those in specific embodiments one to five. Specific implementation method seven: The difference between this embodiment and one of the specific embodiments one to six is ​​that: after curing in step two, the substrate is first immersed in water at 20~50 ℃ for 30 min, and then the film is peeled off. The other steps are the same as those in specific embodiments one to six.

[0031] Specific Implementation Method 8: This implementation method describes the application of a polyetherimide / polyaryletherketone composite material in a dielectric capacitor.

[0032] The beneficial effects of the present invention are verified using the following embodiments: Example 1: A polyetherimide / polyaryletherketone composite material, prepared according to the following steps: Step 1: Prepare a polyetherimide / polyaryletherketone composite solution; 2 g of polyetherimide (PEI) particles were added to a beaker containing 8 ml of N-methylpyrrolidone and initially dispersed under continuous stirring to prevent the subsequent addition of polyaryletherketone (PAEK) from agglomerating. Then, 0.002 g of PAEK was added while stirring to obtain a mixed system. The mixed system was placed on a magnetic stirrer and heated and stirred at 70 °C for 12 h until PEI and PAEK were fully dissolved to form a uniform and transparent polyetherimide / polyaryletherketone composite solution. Step 2: Preparation of polyetherimide / polyaryletherketone composite material; The composite solution obtained in step one is placed in a vacuum oven and vacuumed for 10-12 hours to thoroughly remove air bubbles from the composite solution. The high-temperature resistant glass plate is washed with clean water 1 to 3 times, then wiped clean with lint-free paper, then washed with anhydrous ethanol 3 to 5 times, and finally dried at 50 to 60 ℃ for 1 to 2 hours to obtain the pretreated high-temperature resistant glass plate. The composite solution with fully degassed air bubbles was uniformly coated onto one side of a pretreated high-temperature resistant glass plate. The high-temperature resistant glass plate was then placed in an oven at 80-85 ℃ for curing for 11-12 h. After curing, the film on the high-temperature resistant glass plate was peeled off to obtain a polyetherimide / polyaryletherketone composite material with a polyaryletherketone mass fraction of 0.1%.

[0033] Example 2 The difference between this embodiment and Example 1 is that the mass fraction of polyaryletherketone in the composite material is 0.3%, the amount of polyetherimide remains unchanged, the amount of polyaryletherketone is 0.006 g, and the other steps and process parameters are the same as in Example 1.

[0034] Example 3 The difference between this embodiment and Example 1 is that the mass fraction of polyaryletherketone in the composite material is 0.5%, the amount of polyetherimide remains unchanged, the amount of polyaryletherketone is 0.01 g, and the other steps and process parameters are the same as in Example 1.

[0035] Example 4 The difference between this embodiment and Example 1 is that the mass fraction of polyaryletherketone in the composite material is 0.7%, the amount of polyetherimide remains unchanged, the amount of polyaryletherketone is 0.014 g, and the other steps and process parameters are the same as in Example 1.

[0036] Example 5 The difference between this embodiment and Example 1 is that the mass fraction of polyaryletherketone in the composite material is 0.9%, the amount of polyetherimide remains unchanged, the amount of polyaryletherketone is 0.018 g, and the other steps and process parameters are the same as in Example 1.

[0037] Comparative Example 1 The difference between this comparative example and Example 1 is that no polyaryletherketone is added during the preparation process, and the material prepared is pure polyetherimide. Other steps and process parameters are the same as in Example 1.

[0038] Figure 1 The scanning electron microscope image of the polyetherimide film without polyaryletherketone (PREE) in Comparative Example 1 shows that the fracture surface of the polyetherimide film without PREE is relatively smooth and even. Figure 2 The image shown is a scanning electron microscope (SEM) image of the composite material with a polyaryletherketone (PAE) content of 0.5 wt% in Example 3. Figure 1 The comparison revealed that after adding polyaryletherketone, no large amount of agglomeration occurred on the fracture surface of the composite film, indicating that there was no phase separation between polyetherimide and polyaryletherketone, and that the two have good compatibility.

[0039] DC breakdown Weibull distribution of polyetherimide / polyetheretherketone composites with different mass fractions of polyetheretherketone is shown in the figure. Figure 3 As shown, the breakdown field strength of the composite material increases significantly with the increase of polyaryletherketone (PAEK) mass fraction. This is because the PAEK molecular chain contains a large number of aromatic rings and ketone groups, exhibiting high rigidity and low polarity. This structure helps improve the material's electric field withstand capability and reduces the formation of breakdown paths. The breakdown field strength of pure polyetherimide is 469.1 KV / mm. When the mass fraction of PAEK is 0.1%, the breakdown field strength reaches a maximum of 703.94 KV / mm, which is 50.6% higher than that of pure polyetherimide. This demonstrates that the addition of PAEK improves the energy storage efficiency of polyetherimide.

[0040] The dielectric constant test results of polyetherimide / polyetherketone composites with different mass fractions of polyetherketone are as follows: Figure 4 As shown, it can be observed that the dielectric constant of the composite material increases with the increase of the polyaryletherketone (PAEK) mass fraction. This is because the introduction of PAEK has good compatibility with PEI and does not cause phase separation. Moreover, PAEK reduces the free volume between PEI molecular chains and reduces the charge accumulation in PEI. When the mass fraction of PAEK is 0.9%, the dielectric constant of the composite material is around 10. 3 The frequency is 5.23 Hz, which increases the dielectric constant of pure polyetherimide by 14.6% compared to the same frequency, which is beneficial for the energy storage of PEI materials.

[0041] Strain-stress test results of polyetherimide / polyaryletherketone composites with different mass fractions of polyurethane are as follows: Figure 5As shown, increasing the mass fraction of polyaryletherketone (PAEK) significantly enhances the tensile properties of the composite material. This is because the PAEK molecular chain contains numerous aromatic ring structures, exhibiting high rigidity and tensile modulus. Its addition significantly improves the overall tensile strength and modulus of the composite material. Furthermore, PAEK and PEI have good compatibility at the molecular level, forming a stable blend system that enhances interfacial bonding strength and thus strengthens stress transfer capabilities. When the mass fraction of PAEK is 0.3%, the tensile strength of the composite material increases to 104.68 MPa, a 20.81% increase compared to pure polyetherimide, indicating that the appropriate introduction of PAEK significantly improves the mechanical properties of the film.

[0042] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A polyetherimide / polyaryletherketone composite material that combines high breakdown performance with mechanical toughness, characterized in that, The composite material is made from polyetherimide and polyaryletherketone. The two are mixed by solution blending and then coated onto a substrate, followed by curing.

2. The composite material according to claim 1, characterized in that, The polyetherimide / polyaryletherketone composite material contains 0.1~0.9 wt% polyaryletherketone.

3. A method for preparing the polyetherimide / polyaryletherketone composite material according to claim 1 or 2, characterized in that, The method includes the following steps: Step 1: Preparation of polyetherimide / polyaryletherketone composite solution: Polyetherimide was added to N-methylpyrrolidone, and after stirring, polyaryletherketone was added to obtain a mixed system. The mixed system was heated and stirred until the polyetherimide and polyaryletherketone were fully dissolved to obtain a polyetherimide / polyaryletherketone composite solution. Step 2: Preparation of polyetherimide-polyaryletherketone composite material; The polyetherimide / polyaryletherketone composite solution obtained in step one is degassed under vacuum, then coated onto a pretreated substrate and cured to form a thin film. The thin film on the substrate is then peeled off to obtain the polyetherimide / polyaryletherketone composite material.

4. The preparation method according to claim 3, characterized in that, In step one, the mass-to-volume ratio of polyetherimide to solvent is 2 g: 8 mL, and the mass-to-volume ratio of polyaryletherketone to solvent is (0.002~0.018) g: 8 mL.

5. The preparation method according to claim 3, characterized in that, In step one, the heating temperature is 60~80 ℃, and the heating and stirring time is 8~12 h.

6. The preparation method according to claim 3, characterized in that, The vacuum conditions in step two are: vacuuming time 10~12 h.

7. The preparation method according to claim 3, characterized in that, The pretreatment process in step two is as follows: first, wash the substrate with clean water 1 to 3 times, then wipe it clean with lint-free paper, then wash it with anhydrous ethanol 3 to 5 times, and finally dry it at 50 to 60 ℃ for 1 to 2 hours to obtain the pretreated substrate.

8. The preparation method according to claim 3, characterized in that, In step two, the curing temperature is 80~85 ℃ and the time is 11~12 h.

9. The preparation method according to claim 3, characterized in that, In step two, after curing, the substrate is first immersed in water at 20~50℃ for 30 minutes, and then the film is peeled off.

10. The application of the polyetherimide / polyaryletherketone composite material according to claim 1 or 2, characterized in that, This composite material is used in dielectric capacitors.

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