MXenes two-dimensional material doped polyimide plastic and preparation method thereof

Abstract

The invention discloses an MXenes two-dimensional material doped polyimide plastic and a preparation method thereof, and relates to the field of special engineering plastics, the preparation method comprises the following steps: in an inert gas atmosphere, mixing an MXenes powder material, a first solvent, a dispersant and a coupling agent to obtain an MXenes material dispersion liquid; and adding the MXenes material dispersion liquid, a diamine monomer and a dianhydride monomer into a second solvent, and carrying out a polymerization reaction. The MXenes two-dimensional material is introduced into the polyimide engineering plastic mainly through an in-situ polymerization method, so that the surface resistivity and the volume resistivity of polyimide are remarkably reduced, and the polyimide engineering plastic has excellent antistatic performance. Meanwhile, the material can keep inherent high temperature resistance, mechanical strength and wear resistance of polyimide, uniform dispersion of MXenes in a matrix is ensured through a special preparation process, and the process is simple and suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of special engineering plastics, and more particularly to an MXenes two-dimensional material doped polyimide plastic and its preparation method. Background Technology

[0002] Polyimide (PI), a specialty engineering plastic, is widely used in high-end technology fields such as aerospace, microelectronics, electrical insulation, and the automotive industry due to its excellent high-temperature resistance, superior mechanical strength, good chemical stability, and radiation resistance. However, traditional polyimide materials typically possess extremely high surface resistivity and volume resistivity (usually greater than 10 Ω·cm). 16 (Ω·cm), belonging to the category of insulators. This characteristic makes it prone to static electricity accumulation in certain applications, leading to electrostatic discharge (ESD) hazards, such as damaging precision electronic components, causing safety accidents in flammable and explosive environments, and attracting dust, affecting the appearance and performance of products.

[0003] To impart antistatic properties to polyimide, existing technologies typically employ methods such as adding conductive fillers like carbon black, carbon fibers, carbon nanotubes, and graphene. However, these methods have significant limitations: carbon black requires high addition levels (typically >15 wt%) to form conductive pathways, severely degrading the material's mechanical properties and processing flowability; carbon fibers improve the matrix's wear resistance and dimensional stability, but also suffer from high addition levels, leading to material embrittlement; while carbon nanotubes and graphene, despite their excellent conductivity and low permeation threshold, are prone to agglomeration, making uniform dispersion in the polymer matrix difficult. This often necessitates complex surface modification processes, which are costly and hinder large-scale industrial production and application.

[0004] MXenes are a new class of two-dimensional inorganic compound materials that combine the high conductivity of metals with the high specific surface area of ​​two-dimensional materials. Theoretically, they can construct highly efficient conductive networks in polymer matrices at extremely low addition levels, making them ideal fillers for preparing high-performance conductive composite materials. However, achieving stable and uniform dispersion of MXene nanosheets in a polyimide matrix, while maintaining structural and performance stability under harsh polyimide synthesis conditions (such as high temperature and highly polar solvents) without affecting the inherent excellent properties of polyimide, remains the main technical challenge in this field. Summary of the Invention

[0005] To overcome the problems in the prior art, the present invention provides an MXenes two-dimensional material doped polyimide plastic and its preparation method, specifically providing an MXenes doped polyimide special engineering plastic with excellent antistatic properties, good mechanical properties and processing properties and its preparation method.

[0006] In a first aspect, the present invention provides a method for preparing MXenes two-dimensional material-doped polyimide plastic, comprising the following steps: In an inert gas atmosphere, MXenes powder material, a first solvent, a dispersant and a coupling agent are mixed to obtain an MXenes material dispersion. The MXenes material dispersion, diamine monomer, and dianhydride monomer are added to a second solvent to carry out a polymerization reaction, thereby obtaining a polyamic acid resin solution containing MXenes material. The polyamic acid resin solution containing MXenes material is subjected to imidization powdering treatment to obtain the MXenes two-dimensional material-doped polyimide plastic.

[0007] Furthermore, the MXenes powder material includes at least one of the following materials: Ti3C2Tx, Ti2CTx, V2CTx, Nb2CTx, Ta2CTx, Mo2CTx, Mo2TiC2Tx, Mo2Ti2C3Tx, Cr2TiC2Tx, (Ti,V)3C2Tx, (Mo,V)4C3Tx, (Ti,Nb)2CTx, Mo 1·33 CTx, W 1·33 CTx, Ti4N3Tx, Ti2NTx, Ti3CNTx, Zr3C2Tx, Hf3C2Tx, Ti3C2Cl2, Ti3C2Br2, Ti3C2I2 and Ti3C2(ClBrI), wherein Tx is a surface terminating functional group, including at least one of -O, -OH, -F and -Cl.

[0008] Furthermore, both the first solvent and the second solvent include aprotic polar solvents, which include at least one of N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methylpyrrolidone, and γ-butyrolactone.

[0009] Furthermore, the dispersant includes at least one of triethylhexylphosphate, sodium dodecyl sulfate, methylpentanol, cellulose derivatives, polyacrylamide, glucon, and fatty acid polyethylene glycol esters.

[0010] Further, the coupling agent includes at least one of silane coupling agents and titanate coupling agents, wherein the silane coupling agent includes at least one of trichlorovinylsilane, triethoxyvinylsilane, γ-aminopropyltriethoxysilane, and trichloropropenylsilane, and the titanate coupling agent includes at least one of tetrabutyl titanate, triisostearoyl titanate isopropyl titanate, triisopropyl titanate, and diisostearoyl phthalate ethyl ester.

[0011] Furthermore, the mass ratio of the MXenes powder material to the first solvent is (5~30):(70~95), and the amount of the dispersant and the coupling agent added is 0.5~5wt% of the mass of the MXenes material.

[0012] Further, the diamine monomer includes at least one selected from diaminodiphenyl ether (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), 2,2'-bis(trifluoromethyl-4,4'-biphenyldiamine), bis(aminohydroxyphenyl)hexafluoropropane (DBOH), bis(aminophenoxy)benzene (133APB, 134APB, 144APB), bis(aminophenyl)hexafluoropropane (33-6F, 44-6F), bis(aminophenyl)sulfone (4DDS, 3DDS), bis[(aminophenoxy)phenyl]hexafluoropropane (4BDAF), bis[(aminophenoxy)phenyl]propane (6HMDA), and bis(aminophenoxy)diphenylsulfone (DBSDA). The dianhydride monomers include 1,2,4,5-benzyl pyromellitic dianhydride (PMDA), biphenyl dianhydride (BPDA), oxophthalic dianhydride (ODPA), benzophenone tetracarboxylic dianhydride (BTDA), hexafluoroisopropylphthalic anhydride (6FDA), cyclobutane tetracarboxylic dianhydride (CBDA), bicyclo[2.2.2]oct-7-en-2,3,5,6-tetracarboxylic dianhydride (BTA), and 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA). At least one of benzopyroxene dianhydride, bis(carboxyphenyl)dimethylsilane dianhydride (SiDA), bis(dicarboxyphenoxy)diphenyl sulfide dianhydride (BDSDA), sulfonyl diphthalic anhydride (SO2DPA), and (isopropylidene diphenoxy)bis(phthalic anhydride) (6HDBA).

[0013] Further, the molar ratio of the diamine monomer to the dianhydride monomer is (0.95~1.05):1; The sum of the masses of the diamine monomer, the dianhydride monomer, and the MXenes material accounts for 8% to 40% of the total mass of the polyamic acid resin solution containing the MXenes material, by mass percentage. The MXenes material accounts for 0.1% to 3% of the total mass of the diamine monomer, the dianhydride monomer, and the MXenes material, by mass percentage. The viscosity range of the polyamic acid resin solution containing MXenes material is 10,000 to 1,000,000 cp.

[0014] Further, the step of imidizing the polyamic acid resin solution containing MXenes material into powder to obtain the MXenes two-dimensional material-doped polyimide plastic includes the following processes: Add xylene or acetic anhydride or a mixture thereof to the polyamic acid resin solution containing MXenes material, stir and heat to 160~190°C, stop heating after the powder is completely precipitated, centrifuge and filter the powder mixture solution to obtain polyimide powder; then wash, centrifuge and dry with organic solvent to obtain the MXenes two-dimensional material doped polyimide plastic. The amount of xylene or acetic anhydride or a mixture thereof added, by mass percentage, is 5-30% of the total mass of the polyamic acid resin solution containing MXenes material; The organic solvent includes at least one of DMF, DMAc, NMP, DMSO, THF, acetone, and ethanol; Alternatively, the step of imidizing the polyamic acid resin solution containing MXenes material into powder to obtain the MXenes two-dimensional material-doped polyimide plastic includes the following processes: A catalyst and a dehydrating agent are added to the polyamic acid resin solution containing MXenes material, and the mixture is stirred and heated to 60-80°C. After reacting for 1-8 hours, the resin is slowly added to a poor solvent and stirred to precipitate into powder. Then, the resin is washed, centrifuged, and dried with an organic solvent to obtain the MXenes two-dimensional material-doped polyimide plastic. The catalyst includes pyridine, quinoline, isoquinoline, and triethylamine; the amount of catalyst added is 1-10% by mass percentage of the total mass of the polyamic acid resin solution containing MXenes material. The dehydrating agent includes acetic anhydride, and the amount of the dehydrating agent added is 5-30% of the total mass of the polyamic acid resin solution containing MXenes material. The unsuitable solvents include at least one of methanol, ethanol, isopropanol, acetone, and ultrapure water, and the organic solvents include at least one of DMF, DMAc, NMP, DMSO, THF, acetone, and ethanol.

[0015] Secondly, based on the same inventive concept, the present invention provides an MXenes two-dimensional material doped polyimide plastic, which is prepared by the preparation method of the MXenes two-dimensional material doped polyimide plastic described in the first aspect.

[0016] The technical solutions provided in the embodiments of the present invention have at least the following advantages compared with the prior art: This invention introduces MXenes, a two-dimensional material, into polyimide engineering plastics via in-situ polymerization, significantly reducing the surface resistivity and volume resistivity of polyimide and giving it excellent antistatic properties. Simultaneously, this material maintains the inherent high-temperature resistance, mechanical strength, and wear resistance of polyimide, and a special preparation process ensures the uniform dispersion of MXenes in the matrix. This invention also provides a method for preparing this material, including powder dispersion, resin polymerization, imidization into powder, and powder post-treatment steps. The process is simple and suitable for industrial production. Specifically: 1. This invention can significantly improve the antistatic properties of polyimide materials: the introduction of MXenes material significantly reduces the surface resistivity and volume resistivity of polyimide, making its surface resistivity reach 10. 4 ~10 6 Ω·cm, significantly reduced volume resistivity, providing permanent antistatic effect; 2. The present invention can maintain the inherent excellent properties of polyimide materials: the two-dimensional structure and high specific surface area of ​​MXenes materials enable them to form a conductive network with low addition amount, without affecting the inherent high temperature resistance, mechanical strength and wear resistance of polyimide. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0019] Figure 1 Infrared spectrum of MXenes two-dimensional material doped polyimide plastic provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The technical solution provided by this invention is as follows: This invention provides a method for preparing MXenes two-dimensional material-doped polyimide plastic, comprising the following steps: In an inert gas atmosphere, MXenes powder material, a first solvent, a dispersant and a coupling agent are mixed to obtain an MXenes material dispersion. The MXenes material dispersion, diamine monomer, and dianhydride monomer are added to a second solvent to carry out a polymerization reaction, thereby obtaining a polyamic acid resin solution containing MXenes material. The polyamic acid resin solution containing MXenes material is subjected to imidization powdering treatment to obtain the MXenes two-dimensional material-doped polyimide plastic.

[0022] Specifically, the manufacturing of this material mainly involves three steps: Step 1: Preparation of MXenes material dispersion: Mix MXenes powder with an aprotic polar solvent, and add dispersant and coupling agent. Stir in a high-speed disperser for 1-2 hours with N2 protection throughout. Then grind in a sand mill for 0.5-2 hours, using circulating water for condensation to keep the material temperature not higher than 80°C, to obtain the MXenes material dispersion.

[0023] Step 2, Synthesis of polyamic acid resin containing MXenes material: The resin is prepared by in-situ polymerization. A certain amount of the above MXenes material dispersion is added to an aprotic polar solvent, and after stirring thoroughly, the diamine monomer is dissolved in the solution. Then, the dianhydride monomer is added in batches (at least 3 times) to prepare a resin solution with a certain viscosity.

[0024] Step 3, imidization into powder: Based on the difference in solubility of the imidized polyimide material in aprotic polar solvents, two processes can be used: thermal imidization into powder and precipitation into powder from unsuitable solvents.

[0025] (a) Thermal imidization powder This method is applicable to scenarios where imidized polyimide materials are insoluble in aprotic polar solvents. The specific steps are as follows: Xylene or acetic anhydride, or a mixture thereof, is added to the polyamic acid resin solution containing MXenes. Under rapid stirring, the temperature is quickly raised to 160–190°C. After the powder has completely precipitated, heating is stopped, and the powder mixture is centrifuged and filtered to obtain polyimide powder. Then, the powder is repeatedly washed with an organic solvent and centrifuged to remove xylene or acetic anhydride, as well as incompletely imidized polyamic acid.

[0026] (b) Precipitation of unsuitable solvents into powder This method is suitable for applications where imidized polyimide materials are soluble in aprotic polar solvents. The specific steps are as follows: A catalyst and dehydrating agent were added to the polyamic acid resin solution containing MXenes. Under rapid stirring, the temperature was quickly raised to 60–80°C, and the reaction was allowed to proceed for 1–8 hours. The resin was then slowly added to a poor solvent, and the mixture was rapidly stirred to precipitate into powder. The powder was then repeatedly washed with an organic solvent and centrifuged to remove xylene or acetic anhydride, as well as incompletely imidized polyamic acid.

[0027] Based on the above technical solution, the preparation method may further include the following steps: Step 4, Powder Post-processing: The powder is dried in a vacuum or inert atmosphere with mechanical agitation to prevent agglomeration. Drying is carried out in two stages: the initial drying temperature is 150–180℃ for 2–6 hours, and the final drying temperature is 240–300℃ for 1–8 hours. After drying, the powder is sieved into different particle size grades.

[0028] The MXenes material described in the above technical solution is selected from one or more of the following materials: Ti3C2Tx, Ti2CTx, V2CTx, Nb2CTx, Ta2CTx, Mo2CTx, Mo2TiC2Tx, Mo2Ti2C3Tx, Cr2TiC2Tx, (Ti,V)3C2Tx, (Mo,V)4C3Tx, (Ti,Nb)2CTx, Mo 1·33 CTx, W 1·33 CTx, Ti4N3Tx, Ti2NTx, Ti3CNTx, Zr3C2Tx, Hf3C2Tx, Ti3C2Cl2, Ti3C2Br2, Ti3C2I2, Ti3C2(ClBrI), where Tx is a surface terminating functional group, including -O, -OH, -F, -Cl, etc.

[0029] The aprotic polar solvent described in the above technical solution can be one or more of N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methylpyrrolidone, and γ-butyrolactone.

[0030] The dispersant described in the above technical solution is one or more of the following: triethylhexyl phosphate, sodium dodecyl sulfate, methylpentanol, cellulose derivatives, polyacrylamide, glucon, and fatty acid polyethylene glycol esters.

[0031] The coupling agents described in the above technical solution are mainly silanes and titanates, specifically including one or more of the following: trichlorovinylsilane, triethoxyvinylsilane, γ-aminopropyltriethoxysilane, trichloropropylene silane, tetrabutyl titanate, triisostearoyl titanate isopropyl trititanate, triisopropyl titanate, and diisostearoyl phthalate ethyl ester.

[0032] The MXenes material dispersion is prepared as described in the above technical solution, wherein the mass ratio of MXenes powder to aprotic polar solvent is 5:95 to 30:70, and the amount of dispersant and coupling agent added is 0.5 to 5% of the mass of MXenes material.

[0033] The diamine monomer described in the above technical solution can be one or more of the following: diaminodiphenyl ether (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), 2,2'-bis(trifluoromethyl-4,4'-biphenyldiamine), bis(aminohydroxyphenyl)hexafluoropropane (DBOH), bis(aminophenoxy)benzene (133APB, 134APB, 144APB), bis(aminophenyl)hexafluoropropane (33-6F, 44-6F), bis(aminophenyl)sulfone (4DDS, 3DDS), bis[(aminophenoxy)phenyl]hexafluoropropane (4BDAF), bis[(aminophenoxy)phenyl]propane (6HMDA), and bis(aminophenoxy)diphenylsulfone (DBSDA).

[0034] The dianhydride monomers described in the above technical solutions can be 1,2,4,5-phenylpyridinium tetracarboxylic dianhydride (PMDA), biphenyl tetracarboxylic dianhydride (BPDA), oxophthalic dianhydride (ODPA), benzophenone tetracarboxylic dianhydride (BTDA), hexafluoroisopropylphthalic anhydride (6FDA), cyclobutane tetracarboxylic dianhydride (CBDA), bicyclo[2.2.2]oct-7-en-2,3,5,6-tetracarboxylic dianhydride (BTA), and 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA). One or more of the following: benzopyroxene dianhydride, bis(carboxyphenyl)dimethylsilane dianhydride (SiDA), bis(dicarboxyphenoxy)diphenyl sulfide dianhydride (BDSDA), sulfonyl diphthalic anhydride (SO2DPA), and (isopropylidene diphenoxy)bis(phthalic anhydride) (6HDBA).

[0035] As described in the above technical solution, the molar ratio of diamine to dianhydride monomers is 0.95:1 to 1.05:1; the solid content of the resin solution is 8wt% to 40wt% (i.e., the sum of the mass of diamine, dianhydride, and MXenes material accounts for 8% to 40% of the total solution mass), preferably 12wt% to 30wt%; the mass of MXenes material accounts for 0.1% to 3% of the sum of the mass of diamine, dianhydride, and MXenes material; and the viscosity range of the resin solution is 10,000 to 1,000,000 cp, preferably 200,000 to 400,000 cp.

[0036] As described in the above technical solution, the amount of xylene or acetic anhydride or a mixture thereof added is 5-30% of the total mass of the resin solution. If it is a mixture, the xylene / acetic anhydride ratio is 4:6-9:1. The organic solvent used for washing can be one or more of DMF, DMAc, NMP, DMSO, THF, acetone, and ethanol.

[0037] As described in the above technical solution, the undesirable solvent is precipitated into powder. The catalyst can be pyridine, quinoline, isoquinoline, or triethylamine, and the amount added is 1-10% of the total mass of the resin solution. The dehydrating agent is usually acetic anhydride, and the amount added is 5-30% of the total mass of the resin solution. The undesirable solvent can be one or more of methanol, ethanol, isopropanol, acetone, and ultrapure water. The organic solvent used for washing can be one or more of DMF, DMAc, NMP, DMSO, THF, acetone, and ethanol.

[0038] Unless otherwise specified, all raw materials, reagents, instruments, and equipment used in this invention can be purchased commercially or prepared using existing methods. Furthermore, unless otherwise specified or detailed, the steps and parameters involved can be performed according to the existing MXenes two-dimensional material doped polyimide plastic preparation process steps and parameters, or directly using existing equipment according to the instruction manual. These will not be elaborated upon further in this invention document.

[0039] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed according to national standards. If no corresponding national standard exists, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0040] Example 1 This example provides a two-dimensional doped polyimide plastic based on MXenes materials, the preparation method of which includes the following steps: ① Preparation of Ti3C2Tx dispersion: Under N2 protection, 10g of Ti3C2Tx powder was mixed with 190g of N-methylpyrrolidone (NMP) to prepare a 5 wt% suspension. Sodium dodecyl sulfate (2% by weight of Ti3C2Tx) as a dispersant and γ-aminopropyltriethoxysilane (KH-550) as a coupling agent (1.5% by weight of Ti3C2Tx) were added to the suspension. The mixture was stirred at 2000 rpm for 1.5 hours on a high-speed disperser. The pre-dispersed material was then transferred to a sand mill and ground for 1 hour using zirconia beads as the grinding media under circulating water cooling (temperature controlled below 70℃) to obtain a uniform and stable Ti3C2Tx / NMP dispersion.

[0041] ② Synthesis of polyamic acid (PAA) resin containing Ti3C2Tx: 100g of the prepared Ti3C2Tx / NMP dispersion (equivalent to 5g of Ti3C2Tx) was added to a 500mL four-necked flask equipped with a mechanical stirrer and N2 inlet / outlet. While stirring, 21.818g (0.109 mol) of diaminodiphenyl ether (ODA) monomer was added, and stirring continued until ODA was completely dissolved. After complete dissolution of ODA, 23.618g (0.108 mol) of pyromellitic dianhydride (PMDA) powder was slowly added in four portions, maintaining the reaction temperature below 40℃ throughout. After the addition was complete, the reaction continued for 6 hours to obtain a viscous polyamic acid / Ti3C2Tx composite resin solution with a solid content of approximately 20 wt% and a Ti3C2Tx content of 1.0 wt% (based on the total monomer mass), with a viscosity of approximately 300,000 cp.

[0042] ③ Thermal imidization to form powder: Add 20% by weight of a chemical dehydrating agent (a mixture of acetic anhydride and xylene, volume ratio 7:3) and a small amount of pyridine as a catalyst to the above PAA resin solution. Rapidly heat the mixture to 180°C and react under vigorous stirring; the powder gradually precipitates. After the reaction is complete, cool to room temperature and collect the powder by centrifugation. Wash three times alternately with ethanol and DMF by centrifugation to remove residual solvent, dehydrating agent, and catalyst.

[0043] ④ Powder post-treatment: The washed powder is subjected to two-stage vacuum drying: the first stage is drying at 170℃ for 4 hours; the second stage is drying at 280℃ for 4 hours, accompanied by mechanical stirring to prevent agglomeration. Finally, it is passed through a 400-mesh sieve to obtain Ti3C2Tx doped polyimide special engineering plastic powder (PI / Ti3C2Tx).

[0044] Example 2 This example provides a two-dimensional doped polyimide plastic based on MXenes materials, the preparation method of which includes the following steps: ① Preparation of Mo2TiC2Tx dispersion: Similar steps to those in Example 1 were used, but Ti3C2Tx was replaced with Mo2TiC2Tx powder, and DMAC was used as the solvent to prepare a dispersion with a concentration of 8 wt%. The dispersant was polyethylene glycol fatty acid ester (1.5%), and the coupling agent was tetrabutyl titanate (2%). The mixture was stirred at high speed for 2 hours and then milled for 1.5 hours.

[0045] ② Synthesis of polyamic acid (PAA) resin containing Mo2TiC2Tx: 75g of the above Mo2TiC2Tx / DMAC dispersion (containing 6g MXenes) was added to a reactor. 29.424g (0.147 mol) of ODA and 32.916g (0.150 mol) of biphenyltetracarboxylic dianhydride (BPDA) monomer were added. The solid content of the reaction was controlled at 25 wt%, and the amount of Mo2TiC2Tx added was 0.8 wt%. The reaction yielded a resin solution with a viscosity of approximately 250,000 cp.

[0046] ③ Precipitation of Powder from Unsuitable Solvents: Add 10% pyridine and 15% acetic anhydride by weight of the resin. Under N2 protection, heat to 70℃ and react for 5 hours to complete chemical imidization. Slowly pour the resulting polyimide solution into vigorously stirred anhydrous ethanol to precipitate fibrous powder.

[0047] The subsequent centrifugation, washing, drying and sieving steps were the same as in Example 1 to obtain the powder product (PI / Mo2TiC2Tx).

[0048] Example 3 This example provides a two-dimensional doped polyimide plastic based on MXenes materials, the preparation method of which includes the following steps: ① Preparation of V2CTx dispersion: Following similar steps to Example 1, using V2CTx powder and NMP as solvent, a dispersion with a concentration of 12 wt% was prepared. The dispersant was triethylhexyl phosphoric acid (2.5%), and the coupling agent was isopropyl triisostearoyl titanate (1%). The mixture was stirred at high speed for 1 hour and then milled for 2 hours.

[0049] ② Synthesis of polyamic acid (PAA) resin containing V2CTx: 50g of the above V2CTx / NMP dispersion (containing 6g V2CTx) was added to the reactor. A comonomer system was used: 14.865g (0.074 mol) ODA and 8.611g (0.08 mol) p-phenylenediamine (p-PDA) were added as diamines, and 33.297g (0.152 mol) hexafluorodianhydride (6FDA) was added as dianhydride. The reaction solids content was controlled at 18 wt%, and the MXenes addition amount was 0.5 wt%. The reaction yielded a resin solution with a viscosity of approximately 400,000 cp.

[0050] ③ Thermal imidization to powder: In this embodiment, 6FDA type polyimide is used, which is soluble in NMP after imidization. Therefore, a powdering process using a poor solvent is adopted. The imidization process is the same as step 3 in Example 2. The dehydrating agent is acetic anhydride, the catalyst is isoquinoline, and the poor solvent is a mixture of acetone and water.

[0051] The subsequent processing steps are the same, resulting in a powder product (PI / V2CTx).

[0052] Comparative Example 1 This example provides a polyimide plastic, the preparation method of which includes the following steps: ① Synthesis of pure polyimide resin: Without adding any MXenes material, 200g of NMP solvent was directly added to the reactor. 43.636g (0.218 mol) of ODA monomer was added, and after stirring to dissolve, 47.236g (0.216 mol) of PMDA was added in portions. The solid content of the reaction was controlled to be approximately 20 wt%, and the reaction yielded a pure polyamic acid resin solution with a viscosity of approximately 280,000 cp.

[0053] ② Thermal imidization into powder: The subsequent chemical imidization, precipitation, washing, and drying steps are exactly the same as in Example 1, to obtain pure polyimide powder.

[0054] Test case In this example, the polyimide powders obtained in Examples 1-3 and Comparative Example 1 were pressed into standard test strips under the same process conditions (380℃~420℃, 80MPa pressure, hot pressing) and their performance was tested. The results are shown in Table 1.

[0055] Table 1 As shown in Table 1, the MXenes-doped polyimide materials prepared by the method of the present invention (Examples 1-3), with extremely low MXene addition (0.5%~1.0%), exhibit surface / volume resistivity ranging from the insulator level (>10). 15 The Ω·cm (Ω·cm) was significantly reduced to 10 4 ~10 6 Excellent permanent antistatic properties were achieved within the Ω·cm range. Simultaneously, the mechanical and heat resistance properties of the material remained essentially at the same level as, or even slightly improved, those of pure polyimide without fillers (comparative example), demonstrating the good dispersibility and compatibility of MXenes in the matrix, fully achieving the design objectives of this invention. Furthermore, the infrared spectrum of the MXenes-doped polyimide material obtained in Example 1 is as follows: Figure 1 As shown.

[0056] Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible subranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0057] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing MXenes two-dimensional material-doped polyimide plastic, characterized in that, Includes the following steps: In an inert gas atmosphere, MXenes powder material, a first solvent, a dispersant and a coupling agent are mixed to obtain an MXenes material dispersion. The MXenes material dispersion, diamine monomer, and dianhydride monomer are added to a second solvent to carry out a polymerization reaction, thereby obtaining a polyamic acid resin solution containing MXenes material. The polyamic acid resin solution containing MXenes material is subjected to imidization powdering treatment to obtain the MXenes two-dimensional material-doped polyimide plastic.

2. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The MXenes powder material includes at least one of the following materials: Ti3C2Tx, Ti2CTx, V2CTx, Nb2CTx, Ta2CTx, Mo2CTx, Mo2TiC2Tx, Mo2Ti2C3Tx, Cr2TiC2Tx, (Ti,V)3C2Tx, (Mo,V)4C3Tx, (Ti,Nb)2CTx, Mo 1·33 CTx, W 1·33 CTx, Ti4N3Tx, Ti2NTx, Ti3CNTx, Zr3C2Tx, Hf3C2Tx, Ti3C2Cl2, Ti3C2Br2, Ti3C2I2 and Ti3C2(ClBrI), wherein Tx is a surface terminating functional group, including at least one of -O, -OH, -F and -Cl.

3. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, Both the first solvent and the second solvent include aprotic polar solvents, which include at least one of N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methylpyrrolidone, and γ-butyrolactone.

4. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The dispersant includes at least one of triethylhexylphosphate, sodium dodecyl sulfate, methylpentanol, cellulose derivatives, polyacrylamide, glucon, and fatty acid polyethylene glycol esters.

5. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The coupling agent includes at least one of silane coupling agents and titanate coupling agents. The silane coupling agent includes at least one of trichlorovinylsilane, triethoxyvinylsilane, γ-aminopropyltriethoxysilane, and trichloropropenylsilane. The titanate coupling agent includes at least one of tetrabutyl titanate, triisostearoyl titanate isopropyl trititanate, triisopropyl titanate, and diisostearoyl phthalate ethyl ester.

6. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The mass ratio of the MXenes powder material to the first solvent is (5~30):(70~95), and the amount of the dispersant and the coupling agent added is 0.5~5wt% of the mass of the MXenes material.

7. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The diamine monomer includes at least one of diaminodiphenyl ether (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), 2,2'-bis(trifluoromethyl-4,4'-biphenyldiamine), bis(aminohydroxyphenyl)hexafluoropropane (DBOH), bis(aminophenoxy)benzene (133APB, 134APB, 144APB), bis(aminophenyl)hexafluoropropane (33-6F, 44-6F), bis(aminophenyl)sulfone (4DDS, 3DDS), bis[(aminophenoxy)phenyl]hexafluoropropane (4BDAF), bis[(aminophenoxy)phenyl]propane (6HMDA), and bis(aminophenoxy)diphenylsulfone (DBSDA). The dianhydride monomers include 1,2,4,5-benzyl pyromellitic dianhydride (PMDA), biphenyl dianhydride (BPDA), oxophthalic dianhydride (ODPA), benzophenone tetracarboxylic dianhydride (BTDA), hexafluoroisopropylphthalic anhydride (6FDA), cyclobutane tetracarboxylic dianhydride (CBDA), bicyclo[2.2.2]oct-7-en-2,3,5,6-tetracarboxylic dianhydride (BTA), and 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (TDA). At least one of benzopyroxene dianhydride, bis(carboxyphenyl)dimethylsilane dianhydride (SiDA), bis(dicarboxyphenoxy)diphenyl sulfide dianhydride (BDSDA), sulfonyl diphthalic anhydride (SO2DPA), and (isopropylidene diphenoxy)bis(phthalic anhydride) (6HDBA).

8. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The molar ratio of the diamine monomer to the dianhydride monomer is (0.95~1.05):1; The sum of the masses of the diamine monomer, the dianhydride monomer, and the MXenes material accounts for 8% to 40% of the total mass of the polyamic acid resin solution containing the MXenes material, by mass percentage. The MXenes material accounts for 0.1% to 3% of the total mass of the diamine monomer, the dianhydride monomer, and the MXenes material, by mass percentage. The viscosity range of the polyamic acid resin solution containing MXenes material is 10,000 to 1,000,000 cp.

9. The method for preparing MXenes two-dimensional material-doped polyimide plastic according to claim 1, characterized in that, The step of imidizing the polyamic acid resin solution containing MXenes material into powder to obtain the MXenes two-dimensional material-doped polyimide plastic includes the following process: Add xylene or acetic anhydride or a mixture thereof to the polyamic acid resin solution containing MXenes material, stir and heat to 160~190°C, stop heating after the powder is completely precipitated, centrifuge and filter the powder mixture solution to obtain polyimide powder; then wash, centrifuge and dry with organic solvent to obtain the MXenes two-dimensional material doped polyimide plastic. The amount of xylene or acetic anhydride or a mixture thereof added, by mass percentage, is 5-30% of the total mass of the polyamic acid resin solution containing MXenes material; The organic solvent includes at least one of DMF, DMAc, NMP, DMSO, THF, acetone, and ethanol; Alternatively, the step of imidizing the polyamic acid resin solution containing MXenes material into powder to obtain the MXenes two-dimensional material-doped polyimide plastic includes the following processes: A catalyst and a dehydrating agent are added to the polyamic acid resin solution containing MXenes material, and the mixture is stirred and heated to 60-80°C. After reacting for 1-8 hours, the resin is slowly added to a poor solvent and stirred to precipitate into powder. Then, the resin is washed, centrifuged, and dried with an organic solvent to obtain the MXenes two-dimensional material-doped polyimide plastic. The catalyst includes pyridine, quinoline, isoquinoline, and triethylamine; the amount of catalyst added is 1-10% by mass percentage of the total mass of the polyamic acid resin solution containing MXenes material. The dehydrating agent includes acetic anhydride, and the amount of the dehydrating agent added is 5-30% of the total mass of the polyamic acid resin solution containing MXenes material. The unsuitable solvents include at least one of methanol, ethanol, isopropanol, acetone, and ultrapure water, and the organic solvents include at least one of DMF, DMAc, NMP, DMSO, THF, acetone, and ethanol.

10. A two-dimensional MXene-doped polyimide plastic, characterized in that, The MXenes two-dimensional material doped polyimide plastic was prepared using any one of claims 1 to 9.

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