Preparation method of fluorinated polyimide micro-powder reinforced perfluoroether elastomer, perfluoroether elastomer composite material and preparation method of perfluoroether elastomer composite material

Abstract

The invention provides a preparation method of a fluorinated polyimide micro-powder reinforced perfluoroether elastomer, a perfluoroether elastomer composite material and a preparation method thereof, and belongs to the field of high polymer materials, and the preparation method specifically comprises the following steps: preparing a polyamide acid solution; carrying out thermal imidization reaction on the polyamide acid solution to prepare fluorinated polyimide micro powder; activating the purified fluorinated polyimide micro-powder in an alkaline environment, and carrying out surface grafting reaction on the activated fluorinated polyimide micro-powder and perfluorovinyl ether halide to obtain surface grafting modified fluorinated polyimide micro-powder; and carrying out emulsion copolymerization reaction on the surface-grafted and modified fluorinated polyimide micro-powder to obtain the fluorinated polyimide micro-powder enhanced perfluoroether elastomer emulsion, and a fluorinated polyimide micro-powder enhanced perfluoroether elastomer, a preparation method of the fluorinated polyimide micro-powder enhanced perfluoroether elastomer, a perfluoroether elastomer composite material and a preparation method of the perfluoroether elastomer composite material. According to the treatment scheme, the mechanical property and the high-temperature resistance of the perfluoroether elastomer are remarkably improved, and the perfluoroether elastomer is suitable for high-end applications such as sealing and corrosion-resistant coatings in an extreme environment.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a preparation method of a perfluoroether elastomer reinforced with fluorinated polyimide micropowder, a perfluoroether elastomer composite material, and a preparation method thereof. Background Art

[0002] Due to its excellent chemical corrosion resistance, high temperature resistance and low permeability, perfluoroether elastomers are widely used in fields such as aerospace, petrochemical industry, and semiconductors. However, the mechanical properties and resistance to medium penetration of existing perfluoroether elastomers are still insufficient under high temperature and high pressure environments, which limits their application under more demanding conditions. To improve their properties, inorganic fillers are usually used for reinforcement or organic-inorganic composite modification. However, the interfacial compatibility between traditional fillers and perfluoroether elastomers is poor, making it difficult to achieve a significant improvement in performance.

[0003] In recent years, technological improvements have mainly focused on molecular structure design. Although the introduction of polyamide blocks can construct a physical crosslinking network and improve the material modulus, the introduction of rigid chain segments reduces the fatigue life of the material by more than 30% in dynamic sealing scenarios. This "trade-off in performance" phenomenon stems from the intrinsic characteristics of single-component materials. The perfluorinated structure endows chemical inertness, but the too low surface energy (about 20 mN / m) makes it difficult for traditional inorganic fillers to be effectively dispersed, and it is impossible to achieve a performance breakthrough through composite modification.

[0004] Based on this, there is an urgent need in the art to develop new composite technologies to improve the mechanical properties while maintaining the chemical inertness and corrosion resistance advantages of perfluoroether elastomers. Summary of the Invention

[0005] Therefore, in order to overcome the above-mentioned disadvantages of the prior art, the present invention provides a preparation method of a perfluoroether elastomer reinforced with fluorinated polyimide micropowder, a perfluoroether elastomer composite material, and a preparation method thereof. By strengthening the composite between inorganic and organic phases through interface engineering, the mechanical properties and high temperature resistance of the perfluoroether elastomer are significantly improved, and it is suitable for high-end applications such as sealing and corrosion-resistant coatings in extreme environments.

[0006] To achieve the above object, the present invention provides a method for preparing a perfluoroether elastomer reinforced with fluorinated polyimide micropowder, comprising: S1, using pyromellitic dianhydride and 2,2'-bis(trifluoromethyl)benzidine as monomers, carrying out a polycondensation reaction in a dimethylacetamide solvent under nitrogen protection to prepare a polyamic acid solution with a viscosity of 500-5000 mPa·s; S2, uniformly dispersing the polyamic acid solution in a dimethylacetamide solvent at 100-150 °C, and gradually heating to 200-350 °C to complete the thermal imidization reaction to obtain fluorinated polyimide micropowder; S3, activating the purified fluorinated polyimide micropowder in an alkaline environment at 50-80 °C, and carrying out surface graft modification of the activated fluorinated polyimide micropowder with a perfluoro vinyl ether halide in a molar ratio of 1:0.1-0.5 for 4-8 h to obtain surface graft-modified fluorinated polyimide micropowder; S4, carrying out an emulsion copolymerization reaction of the surface graft-modified fluorinated polyimide micropowder with tetrafluoroethylene, perfluoromethyl vinyl ether and a cyanide-containing vulcanization point monomer to obtain a perfluoroether elastomer emulsion reinforced with fluorinated polyimide micropowder, and further obtaining a perfluoroether elastomer reinforced with fluorinated polyimide micropowder.

[0007] In one embodiment, the fluorinated polyimide micropowder obtained in S2 is dispersed in water, washed with water and methanol in sequence, and then vacuum dried to obtain purified fluorinated polyimide micropowder.

[0008] In one embodiment, the polyamic acid solution is uniformly dispersed in a dimethylacetamide solvent at 100-150 °C by high-speed atomization spraying, and the thermal imidization reaction is completed by gradually heating to 200-350 °C.

[0009] In one embodiment, the perfluoro vinyl ether halide is CF 2 =CFOCF 2 CF 2 X or CF 2 =CFOCF 2 CF 2 CF 2 OCF 2 X, where X is Br or I.

[0010] In one embodiment, in S4, the emulsifying system comprises an ionic surfactant, a non-ionic surfactant and water, and the weight ratio of the ionic surfactant: non-ionic surfactant: water is 15-18 wt%: 10-15 wt%: 67-75 wt%.

[0011] In one embodiment, the chain transfer agent used in the emulsion copolymerization reaction in S4 is at least one of methanol, methyl formate, tert-butyl acetate, methylene iodide, perfluoroalkyl iodide, or 1,4-diiodoperfluorobutane.

[0012] In one embodiment, the perfluoroether elastomer emulsion reinforced with fluorinated polyimide micropowder obtained in S4 is flocculated, and the flocculated perfluoroether elastomer is separated from the liquid by filtration and centrifugation to obtain a perfluoroether elastomer reinforced with fluorinated polyimide micropowder.

[0013] In one embodiment, in S4, deionized water and a pH buffer solution are added to a stirring reaction kettle, the oxygen content is adjusted to less than 10 ppm, and then the temperature is raised to 60-90 °C to obtain an emulsion; the fluorinated polyimide micropowder modified with fluoro vinyl ether halide is added to the emulsion, and the mixture is vigorously stirred to form a mixed solution; after the mixed solution is pressurized to 0.5-1 MPa, perfluoromethyl vinyl ether is added in batches or at one time, and then tetrafluoroethylene is introduced to raise the pressure in the kettle to 2.0-5.0 MPa, and an initiator is added to start the reaction, and then a curing site monomer and a chain transfer agent are added; during the reaction process, tetrafluoroethylene is replenished every time the pressure drops by 0.05 MPa to maintain the pressure constant until the reaction is completed, and a perfluoroether elastomer emulsion containing fluorinated polyimide micropowder is obtained, wherein the addition amount of tetrafluoroethylene is 36-65 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, the addition amount of perfluoromethyl vinyl ether is 34-63 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, and the addition amount of the curing site monomer is 1-3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0014] A preparation method of a perfluoroether elastomer composite material includes: kneading a perfluoroether elastomer reinforced with fluorinated polyimide micropowder, unmodified fluorinated polyimide micropowder, and a crosslinking agent, and through a molding process by pressing and a segmented vulcanization process, a high-temperature resistant perfluoroether elastomer composite material is prepared, and the total addition amount of the fluorinated polyimide micropowder and the unmodified fluorinated polyimide micropowder in the perfluoroether elastomer reinforced with fluorinated polyimide micropowder is 1-6 wt% of the total mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0015] In one embodiment, the addition amount of the fluorinated polyimide micropowder in the perfluoroether elastomer reinforced with fluorinated polyimide micropowder is 1-3 wt% of the total mass of the perfluoroether elastomer without fluorinated polyimide micropowder, and the addition amount of the unmodified fluorinated polyimide micropowder is 2-5 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0016] In one embodiment, the crosslinking agent is tetraphenyltin or cyclohexadecane hexaoxide. The tetraphenyltin accounts for 0.3-0.5 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, and the cyclohexadecane hexaoxide accounts for 0.5-1 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0017] A perfluoroether elastomer composite reinforced with fluorinated polyimide micropowder, which is prepared by the above method.

[0018] Compared with the prior art, the advantages of the present invention are as follows: By using a composite technology to embed fluorinated polyimide micropowders into the perfluoroether polymer matrix, inorganic-organic phase interface strengthening is achieved, and a composite system with excellent interfacial bonding is constructed, significantly improving the mechanical properties and high-temperature resistance of the perfluoroether elastomer composite, thus solving the problems of poor interfacial compatibility, high cost, and insufficient mechanical properties of perfluoroether polymers, making the perfluoroether elastomer composite suitable for high-end applications such as sealing and corrosion-resistant coatings in extreme environments. Through material design and process innovation, while maintaining the inherent chemical stability of the perfluoroether elastomer composite, the problem of synergistically improving interfacial bonding and mechanical properties is breakthroughly solved, filling the technical gap in the application of high-end fluorine elastomers in extreme environments. Brief Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a flowchart of the preparation method of the perfluoroether elastomer composite reinforced with fluorinated polyimide micropowder in the embodiment of the present invention; Figure 2 It is the infrared spectrum and fluorine content (fluorine content 23.1%) of fluorinated polyimide in the embodiment of the present invention. Detailed Embodiments

[0021] The embodiments of the present application will be described in detail below with reference to the drawings.

[0022] The following describes the implementation modes of the present application through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0023] It should be noted that the following describes various aspects of the embodiments within the protection scope of the present invention. It should be obvious that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is illustrative only. Based on the present application, those skilled in the art should understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects described herein can be used to implement the device and / or practice the method. In addition, this device and / or this method can be implemented using other structures and / or functions in addition to one or more of the aspects described herein.

[0024] It also needs to be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner. The diagrams only show the components related to the present application and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in its actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0025] In addition, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0026] It should be specifically noted that, for the convenience of calculation, in this application, except for the ratio of the emulsion system, the reference for the mass ratio of all other components is the perfluoroether elastomer without fluorinated polyimide micropowder. Perfluoromethyl vinyl ether and the vulcanization point monomer are added during the reaction and are completely involved in the reaction; the consumption of TFE (tetrafluoroethylene) is the mass input during the reaction minus the mass recovered after the reaction ends. These three can generate a perfluoroether elastomer without fluorinated polyimide micropowder, so the sum of the mass fractions of these three is 100% (although a chain transfer agent, a crosslinking agent, and / or an initiator can be added during the reaction, the components added in different reactions are different, so they are not included in the perfluoroether elastomer without fluorinated polyimide micropowder). During the emulsion polymerization process, other components are added. For example, although the surface-grafted modified fluorinated polyimide micropowder is completely added to the reaction, it is not included in the 100% of the perfluoroether elastomer without fluorinated polyimide micropowder. Therefore, the superimposed ratio of each component in the subsequent example formulations exceeds 100%.

[0027] As Figure 1 shown, the embodiment of the present application provides a method for preparing a fluorinated polyimide micropowder-reinforced perfluoroether elastomer composite material, and this perfluoroether elastomer composite material is suitable for high-end applications such as sealing and corrosion-resistant coatings in high-temperature and high-pressure environments. The method for preparing this fluorinated polyimide micropowder-reinforced perfluoroether elastomer composite material includes: S1, using pyromellitic dianhydride and 2,2'-bis(trifluoromethyl)benzidine as monomers, carrying out a polycondensation reaction in a dimethylacetamide solvent under nitrogen protection to prepare a polyamic acid solution with a viscosity of 500 - 5000 mPa·s.

[0028] Using pyromellitic dianhydride (PMDA) and 2,2'-bis(trifluoromethyl)benzidine (TFDB) as monomers, carrying out a polycondensation reaction in a dimethylacetamide (DMAc) solvent under nitrogen protection. The temperature of the polycondensation reaction can be controlled at 0 - 30 °C, and the reaction time is 5 - 20 h to obtain a polyamic acid solution with a viscosity of 500 - 5000 mPa·s.

[0029] S2, uniformly dispersing the polyamic acid solution in a dimethylacetamide solvent at 100 - 150 °C, and gradually heating to 200 - 350 °C to complete the thermal imidization reaction to obtain fluorinated polyimide micropowder.

[0030] Uniformly dispersing the polyamic acid solution in a dimethylacetamide solvent (DMAc heat medium) at 100 - 150 °C, and gradually heating to 200 - 350 °C to complete the thermal imidization reaction. In one embodiment, nitrogen is simultaneously introduced for protection and reflux dehydration to obtain fluorinated polyimide FPI micropowder with a particle size of 0.5 - 5 μm.

[0031] AsFigure 2 The infrared spectrum of the fluorinated polyimide (Shimadzu IRAffinity-1S) is shown. After the introduction of fluorine atoms, there is a stretching vibration of the C-F bond in the range of 1000 - 1350 cm -1 and a strong absorption peak appears in the range of 1200 - 1250 cm -1 (including the vibration of the C-F 3 or C-F 2 group); the fluorine content in the fluorinated polyimide is 23.1% (Shimadzu EDX-8100).

[0032] S3. The purified fluorinated polyimide micropowder is activated at 50 - 80 °C in an alkaline environment. After activation, the fluorinated polyimide micropowder and the perfluoro vinyl ether halide are subjected to surface graft modification at a molar ratio of 1:0.1 - 0.5 for 4 - 8 h to obtain the surface graft-modified fluorinated polyimide micropowder.

[0033] The purification of the fluorinated polyimide micropowder can be carried out by at least one of water washing and organic solvent washing. The number of purification and washing times can be set as needed. The organic solvent can be common washing solvents such as methanol, ethanol, and acetone.

[0034] The fluorinated polyimide micropowder is activated at 50 - 80 °C in an alkaline environment. Under alkaline conditions, chemical adsorption or ion exchange reactions may occur on the surface of the fluorinated polyimide micropowder. Hydroxide ions may interact with the surface fluorine atoms or other functional groups, changing the chemical properties of the micropowder surface, thus facilitating the subsequent grafting reaction. The purified fluorinated polyimide micropowder is activated at 50 - 80 °C in an alkaline environment. After activation, the fluorinated polyimide micropowder and the perfluoro vinyl ether halide are subjected to surface graft modification at a molar ratio of 1:0.1 - 0.5 for 4 - 8 h to obtain the surface graft-modified fluorinated polyimide micropowder. This alkaline environment can be a 10 - 20 wt% KOH solution or other strong base solutions with an approximate pH value. Specifically, the purified fluorinated polyimide micropowder is activated at 50 - 80 °C with a 10 - 20 wt% KOH solution. In one embodiment, ultrasonic dispersion (power 200 W, 30 min) can also be added during the grafting reaction to promote the grafting reaction process.

[0035] S4. The surface graft-modified fluorinated polyimide micropowder and tetrafluoroethylene, perfluoromethyl vinyl ether, and a cyanide-containing curing site monomer are subjected to emulsion copolymerization reaction to obtain a perfluoroether elastomer emulsion reinforced with fluorinated polyimide micropowder, and then a perfluoroether elastomer reinforced with fluorinated polyimide micropowder is obtained.

[0036] The surface-grafted modified fluorinated polyimide micropowder is subjected to an emulsion copolymerization reaction with tetrafluoroethylene, perfluoromethyl vinyl ether, and a cyanide-containing vulcanization point monomer to obtain a perfluoroether elastomer emulsion reinforced with fluorinated polyimide micropowder. The vulcanization point monomer introduces crosslinking sites into the polymer chain, converting the linear polymer into a crosslinked polymer with a three-dimensional network structure. The cyanide-containing perfluoroalkoxy compound can be perfluoro-8-cyano-5-methyl-3,6-dioxaoct-1-ene (8-CNVE, i.e., CF 2 =CFOCF 2 CF(CF3)O(CF2) 2 CN). The cyanide-containing compound vulcanization point monomer includes CF 2 =CFO(CF 2 ) n CF(CF 3 )OCF 2 CF 2 CN, n = 1, 2 or 3; CF 2 =CFO(CF 2 )CF(CF 3 ) n O CF 2 CF 2 CN, n = 1, 2 or 3; CF 2 =CFO(CF 2 )CF(CF 3 )O(CF 2 ) m CN, where m is one of 1, 2, 3, 4 or 5. In one embodiment, when the cyanide-containing vulcanization point monomer is 8-CNVE, the weight of 8-CNVE is 1.5 - 3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0037] The principle of the emulsion copolymerization of the surface-grafted modified fluorinated polyimide micropowder with tetrafluoroethylene, perfluoromethyl vinyl ether, and the cyanide-containing vulcanization point monomer is as follows: The hydrophobic fluorinated polyimide micropowder with surface graft modification can be solubilized, and its surface vinyl functional groups undergo a polymerization reaction with tetrafluoroethylene, perfluoromethyl vinyl ether, and the cyanide-containing vulcanization point monomer in the emulsion under the action of an initiator.

[0038] In the above method, fluorinated polyimide micropowders are embedded in a perfluoroether polymer matrix through a composite technology to achieve the strengthening of the inorganic-organic phase interface, construct a composite system with excellent interfacial bonding, significantly improve the mechanical properties and high-temperature resistance of the perfluoroether elastomer composite, thereby solving the problems of poor interfacial compatibility, high cost and insufficient mechanical properties of the perfluoroether polymer, making the perfluoroether elastomer applicable to high-end applications such as sealing and corrosion-resistant coatings in extreme environments. Through material design and process innovation, while maintaining the inherent chemical stability of the perfluoroether elastomer, the problem of synergistically improving interfacial bonding and mechanical properties is breakthroughly solved, filling the technical gap of high-end fluorine elastomers in extreme environment applications.

[0039] In one embodiment, the fluorinated polyimide micropowders obtained in S2 are dispersed in water, washed with water three times and with methanol twice in sequence, and then dried in vacuum at 60 °C to obtain purified fluorinated polyimide micropowders.

[0040] In one embodiment, the polyamic acid solution is uniformly dispersed in a dimethylacetamide solvent at 100-150 °C by high-speed atomization spraying, and the thermal imidization reaction is completed by gradually raising the temperature to 200-350 °C.

[0041] In one embodiment, the perfluoro vinyl ether halide is CF 2 =CFOCF 2 CF 2 X or CF 2 =CFOCF 2 CF 2 CF 2 OCF 2 X, where X is Br or I. The perfluoro vinyl ether halide is preferably CF 2 =CFOCF 2 CF 2 I.

[0042] In one embodiment, in the emulsion copolymerization reaction in S4, the emulsifying system is a composite system of an ionic surfactant and a non-ionic surfactant; the ionic surfactant is selected from at least one of fluoroether carboxylic acid, perfluoro C4-C10 acid salts, alkyl sulfonates or alkyl sulfates, preferably fluoroether carboxylic acid; the non-ionic surfactant is selected from at least one of polyoxyethylene higher fatty acid esters or polyoxyethylene alkyl ethers, preferably polyoxyethylene oleate or polyoxyethylene laurate. In one embodiment, the emulsifying system contains an ionic surfactant, a non-ionic surfactant and water, and the weight ratio among the ionic surfactant: non-ionic surfactant: water is 15-18 wt%: 10-15 wt%: 67-75 wt%.

[0043] In one embodiment, the chain transfer agent used in the emulsion copolymerization reaction in S4 is at least one of methanol, methyl formate, tert-butyl acetate, methylene iodide, perfluoroalkyl iodide or 1,4-diiodoperfluorobutane. In one embodiment, the amount of chain transfer agent added is 0.1-3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0044] In one embodiment, the fluorinated polyimide powder-reinforced perfluoroether elastomer emulsion obtained in S4 is flocculated, and the flocculated perfluoroether elastomer is separated from the liquid by filtration and centrifugation to obtain the fluorinated polyimide powder-reinforced perfluoroether elastomer.

[0045] In one embodiment, in S4, deionized water and pH buffer solution are added to a stirred reactor, and the oxygen content is adjusted to less than 10 ppm and then the temperature is raised to 60-90°C to obtain an emulsion; fluorinated polyimide powder modified by fluorovinyl ether halides is added to the emulsion and vigorously stirred to form a mixed solution; after the mixed solution is pressurized to 0.5-1 MPa, perfluoromethyl vinyl ether is added in batches or all at once, and tetrafluoroethylene is introduced to raise the pressure in the reactor to 2.0-5.0 MPa, and an initiator is added to start the reaction, followed by adding a vulcanization point monomer and a chain transfer agent; during the reaction, TFE is added every time the pressure drops by 0.05 MPa to maintain a constant pressure until the reaction is completed, and a perfluoroether elastomer emulsion containing fluorinated polyimide powder is obtained, wherein the amount of tetrafluoroethylene added is 36-65% of the mass of the perfluoroether elastomer without fluorinated polyimide powder. wt%, the addition amount of perfluoromethyl vinyl ether is 34-63 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, and the addition amount of the vulcanization point monomer is 1-3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0046] Specifically, in S4, deionized water and pH buffer solution are added to a stirred reactor, and the oxygen content is adjusted to less than 10 ppm and then the temperature is raised to 60-90 °C to obtain an emulsion; fluorinated polyimide micropowder modified by fluorovinyl ether halide is added to the emulsion, heated to 40 °C, and vigorously stirred to form a mixed solution; the mixed solution is added to the reactor and the pressure is increased to 0.5-1 MPa; perfluoromethyl vinyl ether (PMVE) is added to the reactor in batches or all at once, and gas-phase monomer tetrafluoroethylene (TFE) is introduced to raise the pressure in the reactor to 2.0-5.0 MPa, potassium persulfate initiator is added to start the reaction, and then the vulcanization point monomer 8-CNVE and chain transfer agent 1,4-diiodoperfluorobutane are added; during the reaction, TFE is added every time the pressure drops by 0.05 MPa to maintain a constant pressure until the reaction is completed, and a perfluoroether elastomer emulsion containing fluorinated polyimide micropowder is obtained. Among them, the addition amount of tetrafluoroethylene is 36-65 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder, the addition amount of perfluoromethyl vinyl ether is 34-63 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder, and the addition amount of the vulcanization point monomer is 1-3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder.

[0047] In one embodiment, the embodiment of the present application also provides a method for preparing a perfluoroether elastomer composite material, comprising: mixing a perfluoroether elastomer reinforced with a fluorinated polyimide powder with an unmodified fluorinated polyimide powder and a cross-linking agent, and obtaining a high-temperature resistant perfluoroether elastomer composite material through compression molding and segmented vulcanization processes.

[0048] The fluorinated polyimide powder-reinforced perfluoroether elastomer can be obtained by directly flocculating the fluorinated polyimide powder-reinforced perfluoroether elastomer emulsion obtained in step S4. In one embodiment, the fluorinated polyimide powder-reinforced perfluoroether elastomer can also be obtained by adding unmodified fluorinated polyimide powder to the fluorinated polyimide powder-reinforced perfluoroether elastomer emulsion.

[0049] The total amount of the fluorinated polyimide powder reinforced with the fluorinated polyimide powder and the unmodified fluorinated polyimide powder is 1-6 wt% of the mass of the perfluoroether elastomer without the fluorinated polyimide powder. Preferably, the total amount of all fluorinated polyimide powders is 2-5 wt% of the mass of the perfluoroether elastomer without the fluorinated polyimide powder.

[0050] In one embodiment, the crosslinking agent is tetraphenyltin or hexacyclooctadecane, wherein the tetraphenyltin is 0.3-0.5 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder, and the hexacyclooctadecane is 0.5-1 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder.

[0051] The perfluoroether elastomer reinforced with fluorinated polyimide micropowder is kneaded with unmodified fluorinated polyimide micropowder and a crosslinking agent, and a high-temperature resistant perfluoroether elastomer composite material is prepared through a process of compression molding and stepwise vulcanization. Compression molding is a process of processing materials into a formed shape through a mold under high temperature (generally above 150 °C) and high pressure (usually 10 MPa). The stepwise vulcanization process refers to dividing the vulcanization process of rubber products into multiple stages, and each stage adopts different temperature, time, and pressure conditions to achieve a more uniform vulcanization effect. Both the compression molding and stepwise vulcanization processes adopt conventional process parameters in the art.

[0052] In one embodiment, the parameters of compression molding are high temperature (heating at 170 °C for 15 min) and high pressure (10 MPa). The parameters of the stepwise vulcanization process are: primary vulcanization at 200 °C for 2 h, and secondary vulcanization at 250 °C for 4 h.

[0053] In one embodiment, the addition amount of the fluorinated polyimide micropowder in the perfluoroether elastomer reinforced with fluorinated polyimide micropowder is 1 - 3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, and the addition amount of the unmodified fluorinated polyimide micropowder is 2 - 5 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0054] In one embodiment, the addition amount of the fluorinated polyimide micropowder in the perfluoroether elastomer reinforced with fluorinated polyimide micropowder during the polymerization in step S3 is 1 - 3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, and the total addition amount of the unmodified fluorinated polyimide micropowder during the kneading process for preparing the composite material is 2 - 5 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder, but the total amount of all fluorinated polyimide micropowders does not exceed 1 - 6 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide micropowder.

[0055] A perfluoroether elastomer composite material reinforced with fluorinated polyimide micropowder, and the perfluoroether elastomer composite material is prepared by the above method.

[0056] Example 1 S1. 0.567 mol of pyromellitic dianhydride (PMDA, molecular weight 218.12, 119.1 g) and 0.54 mol of 2,2'-bis(trifluoromethyl)benzidine (TFDB, molecular weight 320.23, 172.8 g) are added to DMAc solvent according to a molar ratio of 1.05:1, and reacted at 25 °C for 10 h under nitrogen protection at room temperature to obtain a polyamic acid solution with a solid content of 5% and a viscosity of 1200 mPa·s.

[0057] S2. The polyamic acid solution is sprayed into the DMAc system at 120 °C through high-speed atomization (atomization pressure 1.5 MPa), and then gradually heated to 200 - 350 °C under nitrogen protection, and refluxed for dehydration for 6 h to obtain about 250.5 g of fluorinated polyimide FPI micropowder with a particle size of 0.5 - 5 μm, and the yield is about 92%.

[0058] After centrifugally separating the fluorinated polyimide micropowder, it is dispersed with deionized water, and after centrifugal separation, it is repeatedly washed with organic solvents such as ethanol and acetone 3 - 5 times, and finally vacuum dried at 60 °C for 24 h to obtain high-purity fluorinated polyimide micropowder.

[0059] S3. At a temperature of 60 °C, about 120 g of fluorinated polyimide micropowder is activated with 10 wt% KOH lye and then washed and dried; the activated fluorinated polyimide micropowder reacts with perfluorovinyl ether halide (CF 2 =CFOCF 2 CF 2 I, molecular weight 323.94) in a DMAc solution at 80 °C according to a molar ratio of 1:0.1 (the mass of CF 2 =CFOCF 2 CF 2 I is 7.74 g) for a surface grafting modification reaction for 6 h to obtain surface grafting modified fluorinated polyimide micropowder.

[0060] S4. Prepare an emulsion under vigorous stirring, where fluoroether carboxylic acid is 15 wt% (45 g), polyoxyethylene oleate is 15 wt% (45 g), and deionized water is 70 wt% (210 g). Add 23.6 g of fluorinated polyimide micropowder modified with perfluorovinyl ether halide to the emulsion, heat it to 40 °C, and vigorously stir to form a mixed solution.

[0061] In a 5 L stirred reactor, 3500 mL of deionized water accounting for 70% by volume, about 120 mL of acetic acid and sodium acetate (conjugate base) pH buffer solution (pH = 4) were added. After adjusting the oxygen content to less than 10 ppm, the temperature was raised to 60 °C. The mixed solution was added to the reactor, and the pressure was increased to 0.6 MPa. Perfluoromethyl vinyl ether (PMVE, molecular weight 166, about 530 g) was added to the reactor in two portions (2 / 3 at the beginning and 1 / 3 in the middle of the reaction). Gaseous monomer tetrafluoroethylene (TFE) was introduced to raise the pressure in the reactor to 5.0 MPa. 0.3 wt% potassium persulfate (3.5 g) initiator was added to start the reaction, and then the sulfurization point monomer 8-CNVE (about 23.6 g) and the chain transfer agent 1,4-diiodoperfluorobutane (about 6 g) were added. During the reaction, whenever the pressure dropped by 0.05 MPa, TFE was added to maintain a constant pressure until the reaction was completed, obtaining a perfluoroether elastomer emulsion containing fluorinated polyimide micropowder.

[0062] The addition amount of TFE was 53 wt% (about 624 g) of the perfluoroether elastomer mass, the addition amount of PMVE was 45 wt% of the perfluoroether elastomer mass, the addition amount of 8-CNVE was 2 wt% of the perfluoroether elastomer mass, the addition amount of the chain transfer agent was 0.5 wt% of the perfluoroether elastomer mass, and the modified fluorinated polyimide micropowder was added at about 2 wt% according to the mass fraction of the perfluoroether elastomer.

[0063] S5. The perfluoroether elastomer emulsion was coagulated with 10% HNO 3 After washing and vacuum drying at 90 °C for 24 h, about 1178 g of raw rubber was obtained (1178 g was calculated based on TFE and was the weight of the perfluoroether elastomer without the modified fluorinated polyimide micropowder, and the weight of the perfluoroether elastomer reinforced with fluorinated polyimide micropowder was about 1201 g). It was mixed with unmodified fluorinated polyimide micropowder (added at 3 wt% according to the mass fraction of the perfluoroether elastomer, about 35.3 g) and the crosslinking agent tetraphenyltin (0.4 wt% of the perfluoroether elastomer mass, about 4.8 g). After the mixed rubber was molded by compression molding (170 °C × 15 min), it was vulcanized in stages (the first stage at 200 °C × 2 h, the second stage at 250 °C × 4 h) to obtain the perfluoroether elastomer composite material.

[0064] Example 2 S1. 0.672 mol of pyromellitic dianhydride (PMDA, molecular weight 218.12, 146.6 g) and 0.64 mol of 2,2'-bis(trifluoromethyl)benzidine (TFDB, molecular weight 320.23, 204.9 g) were added to DMAc solvent according to a molar ratio of 1.05:1, and reacted at 25 °C for 10 h under nitrogen protection at room temperature to obtain a polyamic acid solution with a solid content of 6% and a viscosity of 1360 mPa·s.

[0065] S2. The polyamic acid solution was sprayed into the DMAc system at 120 °C through high-speed atomization (atomization pressure 1.5 MPa), and then gradually heated to 200 - 350 °C under nitrogen protection and refluxed for dehydration for 6 h to obtain about 330.4 g of fluorinated polyimide FPI micropowder with a particle size of 0.5 - 5 μm and a yield of about 94%.

[0066] The fluorinated polyimide micropowder was centrifuged and dispersed with deionized water, and then repeatedly washed 3 - 5 times with organic solvents such as ethanol and acetone, and finally vacuum dried at 60 °C for 24 h to obtain high-purity fluorinated polyimide micropowder.

[0067] S3. At a temperature of 60 °C, about 120 g of some fluorinated polyimide micropowder was activated with 10 wt% KOH lye, washed and dried, and reacted with perfluoro vinyl ether halide (CF 2 =CFOCF 2 CF 2 I, molecular weight 323.94) in a molar ratio of 1:0.1 (the mass of CF 2 =CFOCF 2 CF 2 I is 7.74 g) for surface grafting modification reaction for 6 h to obtain surface grafting modified fluorinated polyimide micropowder.

[0068] S4. An emulsion was prepared under vigorous stirring, including 15 wt% (45 g) of fluoroether carboxylic acid, 15 wt% (45 g) of polyoxyethylene oleate, and 70 wt% (210 g) of deionized water. 11.5 g of fluorinated polyimide micropowder modified with fluoro vinyl ether halide was added to the emulsion, heated to 40 °C, and vigorously stirred to form a mixed solution.

[0069] In a 5 L stirred reactor, 3500 mL of deionized water accounting for 70% by volume, about 120 mL of acetic acid and sodium acetate (conjugate base) pH buffer solution (pH = 4) were added. After adjusting the oxygen content to less than 10 ppm, the temperature was raised to 60 °C. The mixed solution was added to the reactor, and the pressure was increased to 0.6 MPa. Perfluoromethyl vinyl ether (PMVE, molecular weight 166, about 547 g) was added to the reactor in two portions (2 / 3 at the beginning and 1 / 3 in the middle of the reaction). Gaseous monomer tetrafluoroethylene (TFE) was introduced to raise the pressure in the reactor to 5.0 MPa. 0.3 wt% potassium persulfate (3.4 g) initiator was added to start the reaction, and then sulfurization point monomer 8-CNVE (about 28.5 g) and chain transfer agent 1,4-diiodoperfluorobutane (about 11 g) were added. During the reaction, whenever the pressure dropped by 0.05 MPa, TFE was added to maintain a constant pressure until the reaction was completed, obtaining a perfluoroether elastomer emulsion containing fluorinated polyimide micropowder.

[0070] The addition amount of TFE was 49.5 wt% (about 564.3 g) of the perfluoroether elastomer mass, the addition amount of PMVE was 48 wt% of the perfluoroether elastomer mass, the addition amount of 8-CNVE was 2.5 wt% of the perfluoroether elastomer mass, the addition amount of the chain transfer agent was 1 wt% of the perfluoroether elastomer mass, and the modified fluorinated polyimide micropowder was added at about 1 wt% by mass fraction of the perfluoroether elastomer.

[0071] S5. The perfluoroether elastomer emulsion was coagulated with 10% HNO 3 After washing and vacuum drying at 90 °C for 24 h, 1140 g of raw rubber was obtained (1140 g is the weight of the perfluoroether elastomer calculated based on TFE and does not include the modified fluorinated polyimide micropowder, while the weight of the perfluoroether elastomer reinforced with fluorinated polyimide micropowder is about 1163 g). It was kneaded with unmodified fluorinated polyimide micropowder (added at about 4 wt%, about 45.6 g by mass fraction of the perfluoroether elastomer) and crosslinking agent tetraphenyltin (0.5 wt% of the perfluoroether elastomer mass, about 5.7 g). After the kneaded rubber was molded by compression molding (170 °C × 15 min), it was vulcanized in stages (the first stage at 200 °C × 2 h, the second stage at 250 °C × 4 h) to obtain a perfluoroether elastomer composite material.

[0072] Example 3 The difference from Example 1 is that in the synthesis process, perfluoroether elastomer without adding fluorinated polyimide micropowder was used, but fluorinated polyimide micropowder was added during the kneading process to prepare the perfluoroether elastomer composite material.

[0073] S1. Prepare an emulsion under vigorous stirring conditions, where perfluoroether carboxylic acid is 15 wt% (45 g), polyoxyethylene oleate is 15 wt% (45 g), and deionized water is 70 wt% (210 g). Heat to 40 °C and vigorously stir to form a mixture.

[0074] Add 3500 mL of deionized water, which accounts for 70% of the volume, and about 120 mL of acetic acid and sodium acetate (conjugate base) pH buffer solution (pH = 4) to a 5 L stirring reactor. After adjusting the oxygen content to less than 10 ppm, heat up to 60 °C, add the mixture to the reactor, increase the pressure to 0.6 MPa, and add perfluoromethyl vinyl ether (PMVE, molecular weight 166, about 504 g) to the reactor in two portions (add 2 / 3 at the beginning and 1 / 3 during the mid-stage of the reaction). Introduce gaseous monomer tetrafluoroethylene (TFE) to increase the pressure in the reactor to 5.0 MPa, add 0.3 wt% potassium persulfate (3.4 g) initiator to start the reaction, and then add sulfidation point monomer 8-CNVE (about 22.4 g) and chain transfer agent 1,4-diiodoperfluorobutane (about 5.6 g); during the reaction process, whenever the pressure drops by 0.05 MPa, add TFE to maintain the pressure constant until the reaction is completed to obtain a perfluoroether elastomer emulsion without fluorinated polyimide micropowder.

[0075] The addition amount of TFE is 53 wt% (about 593.6 g) of the perfluoroether elastomer mass, the addition amount of PMVE is 45 wt% of the perfluoroether elastomer mass, the addition amount of 8-CNVE is 2 wt% of the perfluoroether elastomer mass, and the addition amount of the chain transfer agent is 0.5 wt% of the perfluoroether elastomer mass.

[0076] S2. Coagulate the perfluoroether elastomer emulsion with 10% HNO 3 After washing and vacuum drying at 90 °C for 24 h, obtain about 1120 g of raw rubber, mix it with 5 wt% of unmodified fluorinated polyimide micropowder (the sample synthesized in Example 1, about 56 g) and cross-linking agent tetraphenyltin (0.4 wt% of the perfluoroether elastomer mass, about 4.48 g). After molding the mixed rubber by compression molding (170 °C × 15 min), cure it in stages (the first stage is 200 °C × 2 h, and the second stage is 250 °C × 4 h) to obtain a perfluoroether elastomer composite material.

[0077] Comparative Example 1 The difference from Example 1 is that fluorinated polyimide micropowder is not added during the synthesis and mixing processes to prepare the perfluoroether elastomer composite material.

[0078] S1. Prepare an emulsion under vigorous stirring conditions, where perfluoroether carboxylic acid is 15 wt% (45 g), polyoxyethylene oleate is 15 wt% (45 g), and deionized water is 70 wt% (210 g). Heat it to 40 °C and vigorously stir to form a mixture.

[0079] Add 3500 mL of deionized water, which accounts for 70% of the volume, and about 120 mL of acetic acid and sodium acetate (conjugate base) pH buffer solution (pH = 4) to a 5 L stirring reactor. After adjusting the oxygen content to less than 10 ppm, heat it to 60 °C, add the mixture to the reactor, increase the pressure to 0.6 MPa, and add perfluoromethyl vinyl ether (PMVE, molecular weight 166, about 504 g) to the reactor in two portions (add 2 / 3 at the beginning and 1 / 3 in the middle of the reaction). Introduce gaseous monomer tetrafluoroethylene (TFE) to increase the pressure in the reactor to 5.0 MPa, add 0.3 wt% potassium persulfate (3.4 g) initiator to start the reaction, and then add sulfidation point monomer 8-CNVE (about 22.4 g) and chain transfer agent 1,4-diiodoperfluorobutane (about 5.6 g); during the reaction, whenever the pressure drops by 0.05 MPa, add TFE to maintain the pressure constant until the reaction is completed to obtain a perfluoroether elastomer emulsion without fluorinated polyimide micropowder.

[0080] The addition amount of TFE is 53 wt% (about 593.6 g) of the mass of the perfluoroether elastomer, the addition amount of PMVE is 45 wt% of the mass of the perfluoroether elastomer, the addition amount of 8-CNVE is 2 wt% of the mass of the perfluoroether elastomer, and the addition amount of the chain transfer agent is 0.5 wt% of the mass of the perfluoroether elastomer.

[0081] S2. Coagulate the perfluoroether elastomer emulsion with 10% HNO 3 After washing and vacuum drying at 90 °C for 24 h, obtain about 1120 g of raw rubber. Mix it with crosslinking agent tetraphenyltin (0.4 wt% of the mass of the perfluoroether elastomer, about 4.48 g). After molding the mixed rubber by compression molding (170 °C × 15 min), cure it in stages (the first stage is 200 °C × 2 h, the second stage is 250 °C × 4 h) to prepare a perfluoroether elastomer composite material.

[0082] Table 1 shows the performance data of type 214 O-rings (3.53×24.99 mm) prepared from the composite materials of the above examples and comparative examples.

[0083]

[0084] The composition ratio of the elastomer is a rough ratio range calculated based on the TFE, PMVE, and sulfidation point monomer added during the whole reaction process after deducting the unreacted TFE and PMVE.

[0085] Table 2 shows the change rates of various items after the 214-type O-ring is soaked in absolute ethanol (720 h, 23°C). 1 。

[0086]

[0087] Table 3 shows the change rates of various items after the 214-type O-ring is soaked in 49% HF (720 h, 23°C). 1 。

[0088]

[0089] Note 1: See Mori Huan Enterprise Standard Q / SMS 002-2024, Perfluoroether Elastomer and Rubber Seal Ring Immersion and Liquid Resistance Test Method.

[0090] Dimensions for measuring volume and mass changes: 25×50 mm rectangle; Dimensions for measuring hardness and tensile property changes: Type 2 dumbbell-shaped specimen, AS568-214 O-ring.

[0091] In Examples 1-3, by introducing fluorinated polyimide micropowder, the mechanical properties, high-temperature resistance, and chemical stability of the perfluoroether elastomer are significantly improved. In Comparative Example 1, due to the absence of FPI micropowder, the performance is relatively low.

[0092] In Examples 1-3, the solvent resistance performance is also improved by introducing fluorinated polyimide micropowder.

[0093] The above method realizes the composite process of the perfluoroether elastomer (FFKM) matrix and fluorinated polyimide particles, effectively solving the key problem of the mechanical property decline of traditional perfluoroelastomers in high-temperature, high-pressure corrosive media, and is particularly suitable for the dynamic sealing scenarios of semiconductor manufacturing equipment that needs to withstand both high temperature and strong chemical corrosion simultaneously.

[0094] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in this application should be covered by the protection scope of this application.

Claims

1. A method for preparing a fluorinated polyimide powder-reinforced perfluoroether elastomer, characterized in that: include: S1, using pyromellitic anhydride and 2,2'-bis(trifluoromethyl)benzidine as monomers, a polycondensation reaction is carried out in dimethylacetamide solvent under nitrogen protection to prepare a polyamic acid solution with a viscosity of 500-5000 mPa·s; S2, uniformly dispersing the polyamic acid solution in a dimethylacetamide solvent at 100-150° C., gradually increasing the temperature to 200-350° C. to complete a thermal imidization reaction, and obtaining a fluorinated polyimide powder; S3, activating the purified fluorinated polyimide powder in an alkaline environment at 50-80° C., performing surface grafting modification on the activated fluorinated polyimide powder and a perfluorovinyl ether halide at a molar ratio of 1:0.1-0.5, and reacting for 4-8 hours to obtain surface grafted fluorinated polyimide powder; S4, the surface grafted fluorinated polyimide powder is subjected to emulsion copolymerization with tetrafluoroethylene, perfluoromethyl vinyl ether and cyanide-containing sulfurization point monomers to obtain a fluorinated polyimide powder-reinforced perfluoroether elastomer emulsion, and further obtain a fluorinated polyimide powder-reinforced perfluoroether elastomer.

2. The preparation method according to claim 1, characterized in that: The fluorinated polyimide powder obtained in S2 is dispersed in water, washed with water and methanol in sequence, and then vacuum dried to obtain purified fluorinated polyimide powder.

3. The preparation method according to claim 1, characterized in that: The polyamic acid solution is sprayed into a dimethylacetamide solvent at 100-150° C. by high-speed atomization to be uniformly dispersed, and the temperature is gradually increased to 200-350° C. to complete the thermal imidization reaction.

4. The preparation method according to claim 1, characterized in that: The perfluorovinyl ether halogenated compound is CF2=CFOCF2CF2X or CF2=CFOCF2CF2CF2OCF2X, wherein X is Br or I.

5. The preparation method according to claim 1, characterized in that: In S4, the emulsification system comprises an ionic surfactant, a nonionic surfactant and water, The weight ratio of ionic surfactant: nonionic surfactant: water is 15-18 wt%: 10-15 wt%: 67-75 wt%.

6. The preparation method according to claim 1, characterized in that: The chain transfer agent used in the emulsion copolymerization reaction in S4 is at least one of methanol, methyl formate, tert-butyl acetate, methylene iodide, perfluoroalkyl iodide or 1,4-diiodoperfluorobutane.

7. The preparation method according to claim 1, characterized in that: The fluorinated polyimide micropowder-reinforced perfluoroether elastomer emulsion obtained in S4 is flocculated, and the flocculated perfluoroether elastomer is separated from the liquid by filtration and centrifugation to obtain the fluorinated polyimide micropowder-reinforced perfluoroether elastomer.

8. The preparation method according to claim 1, characterized in that: In S4, deionized water and pH buffer solution are added to the stirred reactor, the oxygen content is adjusted to less than 10 ppm, and the temperature is raised to 60-90° C. to obtain an emulsion; adding fluorinated polyimide powder modified by fluorovinyl ether halide to the emulsion and stirring vigorously to form a mixed solution; After the mixed solution is pressurized to 0.5-1 MPa, perfluoromethyl vinyl ether is added in batches or all at once, and tetrafluoroethylene is introduced to raise the pressure in the autoclave to 2.0-5.0 MPa, and an initiator is added to start the reaction, followed by the addition of a vulcanization point monomer and a chain transfer agent; during the reaction, tetrafluoroethylene is added every time the pressure drops by 0.05 MPa to maintain a constant pressure until the reaction is completed, thereby obtaining a perfluoroether elastomer emulsion containing fluorinated polyimide micropowder. Among them, the addition amount of tetrafluoroethylene is 36-65 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder, the addition amount of perfluoromethyl vinyl ether is 34-63 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder, and the addition amount of the vulcanization point monomer is 1-3 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder.

9. A method for preparing a perfluoroether elastomer composite material, characterized in that: include: The perfluoroether elastomer reinforced by fluorinated polyimide micropowder is mixed with unmodified fluorinated polyimide micropowder and a crosslinking agent, and subjected to compression molding and segmented vulcanization processes to obtain a high-temperature resistant perfluoroether elastomer composite material. The total amount of the fluorinated polyimide powder and the unmodified fluorinated polyimide powder added in the fluorinated polyimide powder-reinforced perfluoroether elastomer is 1-6wt% of the total mass of the perfluoroether elastomer without the fluorinated polyimide powder.

10. The preparation method according to claim 9, characterized in that: The amount of the fluorinated polyimide powder added to the fluorinated polyimide powder-reinforced perfluoroether elastomer is 1-3 wt% of the total mass of the perfluoroether elastomer without fluorinated polyimide powder, and the amount of the unmodified fluorinated polyimide powder added is 2-5 wt% of the mass of the perfluoroether elastomer without fluorinated polyimide powder.

11. The preparation method according to claim 9, characterized in that: The cross-linking agent is tetraphenyltin or hexacyclooctadecane, The tetraphenyltin accounts for 0.3-0.5 wt % of the mass of the perfluoroether elastomer without fluorinated polyimide powder, and the hexaoxycyclooctadecane accounts for 0.5-1 wt % of the mass of the perfluoroether elastomer without fluorinated polyimide powder.

12. A perfluoroether elastomer composite material, characterized in that: The perfluoroether elastomer composite material is prepared by the method according to any one of claims 9 to 11.

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