MXene-h-BN hybrids and their preparation and applications, self-lubricating reinforced fabric composites and their preparation

Abstract

This invention belongs to the fields of composite materials and lubrication materials, and provides an MXene-h-BN hybrid, its preparation and application, and a self-lubricating reinforced fabric composite material and its preparation. This invention involves a mercapto-olefin click reaction between functionalized h-BN and silanized MXene under the action of a thermal initiator to obtain the MXene-h-BN hybrid. The MXene-h-BN hybrid prepared by this invention has advantages such as good thermal conductivity, high strength, and good dispersibility. Using the MXene-h-BN hybrid prepared by the above method as a reinforcing modifier to modify self-lubricating fiber fabrics significantly improves the thermal conductivity and tribological properties of the self-lubricating fiber fabrics, thereby extending the stability and service life of the self-lubricating fiber fabric as a lubricating layer in moving parts.

Description

Technical Field

[0001] This invention relates to the fields of composite materials and lubrication materials, and particularly to MXene-h-BN hybrids and their preparation and application, as well as self-lubricating reinforced fabric composites and their preparation. Background Technology

[0002] Self-lubricating spherical plain bearings offer advantages such as small size, light weight, maintenance-free operation, and high reliability. They have replaced traditional oil and grease-lubricated bearings in critical components of equipment such as spacecraft solar panel deployment mechanisms, aircraft landing gear, helicopter propellers, and hinge joints of large hydraulic equipment. The superior performance of self-lubricating spherical plain bearings largely depends on the self-lubricating liner material between the inner and outer rings. These materials mainly include metal and ceramic matrix composites, solid self-lubricating films, polymers and their filled composites, and self-lubricating fiber fabric composites. Among these, self-lubricating fiber fabric composites possess high tensile strength, high modulus, excellent wear resistance, good fatigue performance, and strong design flexibility. They are widely used in key components of aircraft engines, landing gear, and flaps / ailerons both domestically and internationally, demonstrating a very broad application prospect.

[0003] However, traditional fabric composites tend to accumulate significant frictional heat during friction, leading to severe wear and premature failure of the friction material. Generally, introducing nanofillers (such as inorganic nanoparticles, nanowires, and graphene oxide) into fabric composites is a promising method for enhancing the properties of polymer composites. Unlike traditional fillers, the nano-effects of nanoparticles can exhibit higher interactions with the matrix, thus providing unique properties. MXene, favored for its high thermal conductivity, abundant surface functional groups, and excellent mechanical properties, is also a promising alternative lubricant in composites, enhancing tribological properties. However, van der Waals interactions between pristine MXene nanosheets cause MXene to aggregate during collection and processing, further resulting in poor dispersion of MXene in the resin matrix and limiting its inherent mechanical properties. Furthermore, the weak interfacial compatibility between MXene and resin increases interfacial thermal resistance, thereby reducing the potential thermal conductivity of MXene. Therefore, surface modification of MXene nanosheets containing abundant functional groups is often necessary to overcome its inherent defects.

[0004] Compared to the chemical functionalization of MXene with large / small molecules, introducing inorganic materials (forming hybrids) onto its surface to construct hierarchical nanostructures is also an effective strategy to further improve the performance of MXene. Hexagonal boron nitride has a similar structure and physicochemical properties to graphene and exhibits excellent mechanical strength, biocompatibility, and thermal conductivity. Supporting MXene sheets with nano-boron nitride not only prevents the aggregation of MXene and nanoparticles themselves but also leverages its own advantages to achieve specific properties.

[0005] Numerous studies have reported the preparation of hybrids via sol-gel methods, in-situ grafting, and electrostatic self-assembly. However, the complexity of these methods and the potential for contamination limit their application in various fields. The sol-gel method involves solidifying compounds containing highly chemically active components through solution, sol, and gel processes, followed by heat treatment to produce oxides or other solid compounds. It is widely used in the preparation of thermal insulation materials, acoustic impedance coupling materials, dielectric materials, organic-inorganic hybrid materials, and corrosion-resistant metal-ceramic coatings. However, it suffers from several drawbacks: the raw materials used are relatively expensive, some being organic compounds that are harmful to health; the entire experimental process is typically time-consuming, often requiring several days or weeks; and the gel contains numerous micropores, which release gases and organic matter during drying, leading to shrinkage. Therefore, the mechanical and thermal properties of hybrids synthesized using these methods are affected. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide an MXene-h-BN hybrid, its preparation and application, and a self-lubricating reinforced fabric composite material and its preparation. The MXene-h-BN hybrid obtained by this invention has the advantages of good thermal conductivity, high strength, and good dispersibility.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0008] This invention provides a method for preparing MXene-h-BN hybrids, comprising the following steps:

[0009] Sulfuric acid, hydrogen peroxide and hexagonal boron nitride are mixed and hydroxylated to obtain hydroxylated hexagonal boron nitride;

[0010] The hydroxylated hexagonal boron nitride was functionalized using a first silane reagent to obtain functionalized h-BN; the first silane reagent was a silane reagent containing a double bond;

[0011] MXene nanosheets were obtained by etching Ti3AlC2 using the LiF+HCl system;

[0012] The MXene nanosheets and the second silane reagent are mixed and subjected to a hydrolysis reaction to obtain silanized MXene; the second silane reagent is a silane reagent containing a thiol group.

[0013] The silanized MXene and functionalized h-BN were dispersed in a solvent and subjected to a mercapto-alkene click reaction under the action of a thermal initiator to obtain the MXene-h-BN hybrid.

[0014] Preferably, the ratio of sulfuric acid, hydrogen peroxide, and hexagonal boron nitride is 5-20 mL: 20-60 mL: 1-8 g; the mass concentration of sulfuric acid is 60-98%, and the mass concentration of hydrogen peroxide is 20-30%.

[0015] The hydroxylation is performed at a temperature of 40–80°C for a time of 6–18 hours.

[0016] The silane reagents containing double bonds include γ-methacryloxypropyltrimethoxysilane and / or vinyltriethoxysilane;

[0017] The ratio of the first silane reagent to hydroxylated hexagonal boron nitride is 2–40 mL: 0.2–6 g;

[0018] The functionalization temperature is 40–200°C, and the time is 4–22 hours.

[0019] Preferably, the silane reagent containing mercapto groups includes γ-mercaptopropyltriethoxysilane and / or γ-mercaptopropyltrimethoxysilane; the ratio of the amount of MXene nanosheets to the amount of the second silane reagent is 0.4–8 g: 4–60 mL;

[0020] The hydrolysis reaction is carried out at a temperature of 60–220°C for a duration of 4–22 hours.

[0021] Preferably, the mass ratio of silanized MXene to functionalized h-BN is 0.06–2:0.08–4;

[0022] The thermal initiator is azobisisobutyronitrile and / or benzoyl peroxide;

[0023] The mass ratio of silanized MXene to thermal initiator is 0.06–2:0.002–0.8;

[0024] The click reaction of the mercapto-alkene is carried out at a temperature of 20–160 °C for a time of 2–16 h.

[0025] The present invention also provides MXene-h-BN hybrids prepared by the preparation method described above.

[0026] The present invention also provides the application of the MXene-h-BN hybrid described in the above technical solution in self-lubricating reinforced fabric composites.

[0027] The present invention also provides a self-lubricating reinforced fabric composite material, the raw materials for which include: MXene-h-BN hybrid, adhesive and self-lubricating fiber fabric;

[0028] The adhesive is a resin;

[0029] The self-lubricating fiber fabric is a PPS / PTFE self-lubricating pad material;

[0030] The mass of the MXene-h-BN hybrid is 0.8–16% of the mass of the adhesive.

[0031] Preferably, the resin is one or two of phenolic resin, polyimide resin, epoxy resin, and polyamide-imide;

[0032] The microstructure of the PPS / PTFE self-lubricating pad material is one of plain weave, twill weave, satin weave, or an evolved structure.

[0033] The PPS / PTFE self-lubricating pad material has a warp density of 240–400 and a weft density of 220–360.

[0034] The present invention also provides a method for preparing the self-lubricating reinforced fabric composite material described in the above technical solution, comprising the following steps:

[0035] The MXene-h-BN hybrid was dispersed in an adhesive to obtain a filler dispersion.

[0036] Surface activation of self-lubricating fiber fabric was achieved by air plasma etching, resulting in activated self-lubricating fiber fabric.

[0037] The activated self-lubricating fiber fabric is immersed in the filler dispersion solution, taken out, and cured to obtain the self-lubricating reinforced fabric composite material.

[0038] Preferably, the power of the air plasma etching is 40–220 W, and the time is 6–40 min;

[0039] The curing temperature is 100–240°C, the pressure is 0.1–1 MPa, the time is 80–200 min, and the rate of heating to the curing temperature is 2–26°C / min.

[0040] This invention provides a method for preparing an MXene-h-BN hybrid, comprising the following steps: mixing sulfuric acid, hydrogen peroxide, and hexagonal boron nitride, and performing hydroxylation to obtain hydroxylated hexagonal boron nitride; functionalizing the hydroxylated hexagonal boron nitride with a first silane reagent to obtain functionalized h-BN; wherein the first silane reagent is a silane reagent containing double bonds; etching Ti3AlC2 using a LiF+HCl system to obtain MXene nanosheets; mixing the MXene nanosheets with a second silane reagent and performing a hydrolysis reaction to obtain silanized MXene; wherein the second silane reagent is a silane reagent containing thiol groups; dispersing the silanized MXene and functionalized h-BN in a solvent, and performing a thiol-alkene click reaction under the action of a thermal initiator to obtain the MXene-h-BN hybrid.

[0041] This invention uses sulfuric acid and hydrogen peroxide to hydroxylate h-BN nanosheets to obtain h-BN-OH; etching Ti3AlC2 using a LiF+HCl system to prepare MXene(Ti3C2) nanosheets; functionalizing the hydroxylated h-BN with a first silane reagent to prepare functionalized h-BN; functionalizing MXene with a second silane reagent to prepare silanized MXene; and subjecting the functionalized h-BN and silanized MXene to a mercapto-olefin click reaction under the action of a thermal initiator to obtain an MXene-h-BN hybrid. The MXene-h-BN hybrid prepared by this invention has advantages such as good thermal conductivity, high strength, and good dispersibility. Using the MXene-h-BN hybrid prepared by the above method as a reinforcing modifier to modify self-lubricating fiber fabrics significantly improves the thermal conductivity and tribological properties of the self-lubricating fiber fabrics, thereby extending the stability and service life of the self-lubricating fiber fabrics as a lubricating layer in moving parts. Attached Figure Description

[0042] Figure 1 XRD patterns of h-BN, h-BN-MPS, MXene nanosheets (Ti3C2), MXene-MPTEs (Ti3C2-MPTEs), and MXene-h-BN (Ti3C2-h-BN);

[0043] Figure 2 XPS images of h-BN, hydroxylated hexagonal boron nitride (h-BN-OH), MXene nanosheets (Ti3C2), and MXene-h-BN (Ti3C2-h-BN);

[0044] Figure 3The data provided are the friction and wear data of the self-lubricating fabric composite materials obtained in the examples and comparative examples, wherein (a) is the wear rate of the self-lubricating fabric composite materials obtained in the examples and comparative examples, and (b) is the friction coefficient of the self-lubricating fabric composite materials obtained in the examples and comparative examples.

[0045] Figure 4 The wear surface morphology of the self-lubricating fabric composite material obtained in Comparative Example 1 and Example 1;

[0046] Figure 5 The tensile strength of the self-lubricating fabric composite materials obtained in the comparative examples and embodiments;

[0047] Figure 6 The thermal conductivity of the self-lubricating fabric composites obtained in the comparative examples and embodiments is measured at room temperature and 150°C. Detailed Implementation

[0048] This invention provides a method for preparing MXene-h-BN hybrids, comprising the following steps:

[0049] Sulfuric acid, hydrogen peroxide and hexagonal boron nitride are mixed and hydroxylated to obtain hydroxylated hexagonal boron nitride;

[0050] The hydroxylated hexagonal boron nitride was functionalized using a first silane reagent to obtain functionalized h-BN; the first silane reagent was a silane reagent containing a double bond;

[0051] MXene nanosheets were obtained by etching Ti3AlC2 using the LiF+HCl system;

[0052] The MXene nanosheets and the second silane reagent are mixed and subjected to a hydrolysis reaction to obtain silanized MXene; the second silane reagent is a silane reagent containing a thiol group.

[0053] The silanized MXene and functionalized h-BN were dispersed in a solvent and subjected to a mercapto-alkene click reaction under the action of a thermal initiator to obtain the MXene-h-BN hybrid.

[0054] Unless otherwise specified, all raw materials used in this invention are preferably commercially available products.

[0055] This invention involves mixing sulfuric acid, hydrogen peroxide, and hexagonal boron nitride, and then hydroxylating the mixture to obtain hydroxylated hexagonal boron nitride.

[0056] In this invention, the mass concentration of the sulfuric acid is preferably 60-98%. In this invention, the mass concentration of the hydrogen peroxide is preferably 20-30%.

[0057] In this invention, the preferred ratio of sulfuric acid, hydrogen peroxide and hexagonal boron nitride is 5-20 mL: 20-60 mL: 1-8 g.

[0058] In this invention, the hydroxylation temperature is preferably 40–80°C, and the time is preferably 6–18 h.

[0059] In this invention, the preferred method of hydroxylation by mixing sulfuric acid, hydrogen peroxide, and hexagonal boron nitride includes: mixing sulfuric acid and hydrogen peroxide to obtain a hydroxylating agent; dispersing hexagonal boron nitride in water to obtain a hexagonal boron nitride dispersion; and adding the hydroxylating agent to the hexagonal boron nitride dispersion to perform hydroxylation.

[0060] Following the hydroxylation, the present invention preferably further includes: performing solid-liquid separation on the obtained hydroxylated system, and sequentially washing and drying the resulting filter residue. In this invention, the washing reagent preferably includes water and ethanol, wherein the water is preferably deionized water and the ethanol is preferably anhydrous ethanol. In this invention, the drying temperature is preferably 60°C, and the drying time is preferably 2 hours.

[0061] After obtaining hydroxylated hexagonal boron nitride, the present invention functionalizes the hydroxylated hexagonal boron nitride using a first silane reagent to obtain functionalized h-BN.

[0062] In this invention, the first silane reagent is a silane reagent containing a double bond; the silane reagent containing a double bond preferably includes γ-methacryloxypropyltrimethoxysilane (MPS) and / or vinyltriethoxysilane, and more preferably γ-methacryloxypropyltrimethoxysilane (MPS).

[0063] In this invention, the preferred ratio of the first silane reagent to hydroxylated hexagonal boron nitride is 2-40 mL: 0.2-6 g.

[0064] In this invention, the functionalization temperature is preferably 40–200°C, and the time is preferably 4–22 h. In this invention, the functionalization pH value is preferably 2–6, more preferably 4. In this invention, the functionalization is preferably carried out under reflux and stirring conditions.

[0065] In this invention, the functionalization of the hydroxylated hexagonal boron nitride using a first silane reagent preferably includes the following steps: dispersing the hydroxylated hexagonal boron nitride in a solvent to obtain a hydroxylated hexagonal boron nitride dispersion; adding the first silane reagent to the hydroxylated hexagonal boron nitride dispersion for functionalization. In this invention, the solvent is preferably ethanol and water; the volume ratio of ethanol to water is preferably 2–6:0.5–2, more preferably 3:1; the ethanol is preferably anhydrous ethanol, and the water is preferably deionized water. In this invention, the dispersion is preferably carried out under ultrasonic conditions, and the dispersion time is preferably 40–120 min.

[0066] After functionalization, the present invention preferably further includes: performing solid-liquid separation on the obtained functionalized system, and washing and drying the resulting filter residue sequentially. In the present invention, the washing reagent is preferably anhydrous ethanol. In the present invention, the drying temperature is preferably 80°C.

[0067] This invention utilizes the LiF+HCl system to etch Ti3AlC2 to obtain MXene nanosheets.

[0068] In this invention, the concentration of HCl is preferably 6–12 mol / L. In this invention, the preferred ratio of LiF to HCl is 1–6 g: 40–100 mL. In this invention, the preferred ratio of LiF to Ti3AlC2 is 1–6 g: 1–8 g.

[0069] In this invention, the etching temperature is preferably 30-50°C, and the etching time is preferably 24-48 hours.

[0070] In this invention, the etching of Ti3AlC2 using the LiF+HCl system preferably includes the following steps: mixing lithium fluoride and hydrochloric acid to obtain a first mixed system; adding Ti3AlC2 to the first mixed system for etching. In this invention, the first mixing is preferably carried out under stirring conditions, and the stirring time is preferably 5–20 minutes.

[0071] After etching, the present invention preferably includes: centrifuging the obtained crude product in deionized water until the pH of the supernatant is 5-7; dispersing the lower precipitate in deionized water, sonicating and centrifuging to peel off Ti3C2 nanosheets; and finally, freeze-drying the resulting dark green supernatant to obtain monolayer and few-layer Ti3C2. In the present invention, the centrifugation speed is preferably 2000-4000 rpm, and the time is preferably 1-6 min.

[0072] After obtaining MXene nanosheets, the present invention mixes the MXene nanosheets with a second silane reagent and performs a hydrolysis reaction to obtain silanized MXene.

[0073] In this invention, the second silane reagent is a silane reagent containing a mercapto group; the silane reagent containing a mercapto group preferably includes γ-mercaptopropyltriethoxysilane (MPTEs) and / or γ-mercaptopropyltrimethoxysilane, and more preferably γ-mercaptopropyltriethoxysilane (MPTEs).

[0074] In this invention, the preferred ratio of the amount of MXene nanosheets to the amount of the second silane reagent is 0.4–8 g: 4–60 mL.

[0075] In this invention, the hydrolysis reaction is preferably carried out at a temperature of 60–220°C and for a time of 4–22 hours. The pH value of the hydrolysis is preferably 2–6, more preferably 4. The hydrolysis is preferably carried out under reflux and stirring conditions.

[0076] In this invention, the hydrolysis reaction of the MXene nanosheets and the second silane reagent preferably includes: dispersing the MXene nanosheets in a solvent to obtain an MXene nanosheet dispersion; adding the second silane reagent to the MXene nanosheet dispersion to carry out the hydrolysis reaction. In this invention, the solvent is preferably ethanol and water, and the volume ratio of ethanol to water is preferably 2–6:0.5–2, more preferably 3:1; the ethanol is preferably anhydrous ethanol, and the water is preferably deionized water. In this invention, the dispersion is preferably carried out under ultrasonic conditions, and the dispersion time is preferably 40–120 min.

[0077] Following the hydrolysis reaction, the present invention preferably further includes: performing solid-liquid separation on the obtained hydrolysis reaction system, and sequentially washing and drying the resulting filter residue. In the present invention, the washing reagent is preferably anhydrous ethanol. In the present invention, the drying temperature is preferably 60–80°C.

[0078] After obtaining functionalized h-BN and silanized MXene, the present invention disperses the silanized MXene and functionalized h-BN in a solvent and performs a mercapto-alkene click reaction under the action of a thermal initiator to obtain the MXene-h-BN hybrid.

[0079] In this invention, the solvent is preferably N,N-dimethylformamide (DMF). In this invention, the preferred ratio of silanized MXene to solvent is 0.6–2 g: 80–400 mL.

[0080] In this invention, the preferred mass ratio of silanized MXene to functionalized h-BN is 0.06–2:0.08–4.

[0081] In this invention, the dispersion is preferably carried out under ultrasonic conditions, and the dispersion time is preferably 20 to 140 minutes.

[0082] In this invention, the thermal initiator is preferably azobisisobutyronitrile (AIBN) and / or benzoyl peroxide, more preferably azobisisobutyronitrile (AIBN). In this invention, the mass ratio of the silanized MXene to the thermal initiator is preferably 0.06–2:0.002–0.8.

[0083] In this invention, the temperature of the mercapto-alkene click reaction is preferably 20–160°C, and the time is preferably 2–16 h. In this invention, the mercapto-alkene click reaction is preferably carried out under stirring conditions.

[0084] Following the thiol-alkene click reaction, the present invention preferably further includes: performing solid-liquid separation on the obtained thiol-alkene click reaction system, and washing and drying the resulting filter residue sequentially. In the present invention, the washing reagent is preferably anhydrous ethanol. In the present invention, the drying temperature is preferably 40–100°C.

[0085] The present invention also provides MXene-h-BN hybrids prepared by the preparation method described above.

[0086] The present invention also provides the application of the MXene-h-BN hybrid described in the above technical solution in self-lubricating reinforced fabric composites.

[0087] The present invention also provides a self-lubricating reinforced fabric composite material, the raw materials for which include: MXene-h-BN hybrid, adhesive and self-lubricating fiber fabric.

[0088] The raw materials for preparing the self-lubricating reinforced fabric composite material provided by this invention include MXene-h-BN hybrid. In this invention, the mass of the MXene-h-BN hybrid is 0.8% to 16% of the mass of the adhesive.

[0089] The self-lubricating reinforced fabric composite material provided by this invention includes an adhesive, which is a resin. In this invention, the resin is preferably one or two of phenolic resin, polyimide resin, epoxy resin, and polyamide-imide.

[0090] The self-lubricating reinforced fabric composite material provided by this invention comprises a self-lubricating fiber fabric, wherein the self-lubricating fiber fabric is a PPS / PTFE self-lubricating pad material. In this invention, the microstructure of the PPS / PTFE self-lubricating pad material is preferably one of plain weave, twill weave, satin weave, or a modified structure; the modified structure preferably includes a plain weave modified structure, a twill weave modified structure, a satin weave modified structure, a plain weave-twill weave modified structure, a plain weave-satin weave modified structure, a twill weave-satin weave modified structure, or a plain weave-twill-satin weave modified structure. In this invention, the warp density of the PPS / PTFE self-lubricating pad material is preferably 240–400, and the weft density is preferably 220–360. In this invention, the reinforcing fiber of the PPS / PTFE self-lubricating pad material is preferably PPS fiber, and the lubricating fiber is preferably PTFE fiber.

[0091] The present invention also provides a method for preparing the self-lubricating reinforced fabric composite material described in the above technical solution, comprising the following steps:

[0092] The MXene-h-BN hybrid was dispersed in an adhesive to obtain a filler dispersion.

[0093] Surface activation of self-lubricating fiber fabric was achieved by air plasma etching, resulting in activated self-lubricating fiber fabric.

[0094] The activated self-lubricating fiber fabric is immersed in the filler dispersion solution, taken out, and cured to obtain the self-lubricating reinforced fabric composite material.

[0095] This invention disperses MXene-h-BN hybrids in an adhesive to obtain a filler dispersion.

[0096] In this invention, the types and amounts of the MXene-h-BN hybrid and adhesive are the same as those in the above-described technical solution, and will not be repeated here.

[0097] This invention utilizes air plasma etching to activate the surface of self-lubricating fiber fabrics, thereby obtaining activated self-lubricating fiber fabrics.

[0098] Before surface activation of the self-lubricating fiber fabric, the present invention preferably includes a pretreatment, which preferably includes desizing, washing, and drying. In the present invention, the washing is capable of removing the oil from the self-lubricating fiber fabric.

[0099] In this invention, the power of the air plasma etching is preferably 40-220W, and the time is preferably 6-40min.

[0100] After obtaining the activated self-lubricating fiber fabric, the present invention immerses the activated self-lubricating fiber fabric in the filler dispersion solution, takes it out, and cures it to obtain the self-lubricating reinforced fabric composite material.

[0101] After impregnation, the present invention preferably further includes drying; the drying temperature is preferably 35-80°C; the drying is preferably carried out in an oven.

[0102] In this invention, the process of impregnation and drying can be stopped when the proportion of PPS / PTFE fiber fabric reaches 50-80 wt%.

[0103] In this invention, the curing temperature is preferably 100-240°C, the pressure is preferably 0.1-1 MPa, the time is preferably 80-200 min, and the rate of heating to the curing temperature is preferably 2-26°C / min.

[0104] The following examples illustrate in detail the MXene-h-BN hybrids provided by this invention, their preparation and application, and the self-lubricating reinforced fabric composites and their preparation. However, these examples should not be construed as limiting the scope of protection of this invention.

[0105] Comparative Example 1

[0106] (1) PPS / PTFE fiber fabric (warp density of 326, weft density of 290, and twill weave structure) is woven with PPS fiber and PTFE fiber. After desizing and cleaning with fiber surface oil, it is dried for later use. Subsequently, the fiber fabric is subjected to fiber surface activation treatment in air plasma. The plasma treatment power is 200W and the time is 10min to obtain activated self-lubricating fiber fabric.

[0107] (2) The activated self-lubricating fiber fabric was repeatedly impregnated in phenolic resin solution until the fabric mass fraction reached 75±5wt% to obtain uncured PPS / PTFE fiber fabric (Pure FC). Phenolic resin adhesive was used to bond it to the surface of the metal substrate and cured at 184℃ for 2h to obtain the lubricating fiber fabric composite material test piece.

[0108] (3) Under room temperature conditions, with a dynamic load of 30 MPa and a rotation speed of 760 rpm, the friction test lasted for 2 hours. The average coefficient of friction and wear rate of the self-lubricating fabric composite material were 0.0479 and 2.79 × 10⁻⁶, respectively. -14 m 3 / N·m.

[0109] Comparative Example 2

[0110] (1) PPS / PTFE fiber fabric (radial density of 326, weft density of 290, and twill weave structure) is woven with PPS and PTFE fibers. After desizing and cleaning with fiber surface oil, it is dried for later use. Subsequently, the fiber fabric is subjected to fiber surface activation treatment in air plasma. The plasma treatment power is 200W and the time is 10min to obtain activated self-lubricating fiber fabric.

[0111] (2) The activated self-lubricating fiber fabric was repeatedly impregnated in a phenolic resin solution containing h-BN (the mass fraction of h-BN relative to phenolic resin was 1 wt%) until the mass fraction of the fabric reached 75 ± 5 wt%, and an uncured PPS / PTFE fiber fabric (h-BN / FC) was obtained. The fabric was then bonded to the surface of a metal substrate using a phenolic resin adhesive and cured at 184 °C for 2 h to obtain a self-lubricating fiber fabric composite material test piece.

[0112] (3) Under room temperature conditions, with a dynamic load of 30 MPa and a rotation speed of 760 rpm, the friction test lasted for 2 hours. The average coefficient of friction and wear rate of the self-lubricating fabric composite material were 0.0457 and 2.09 × 10⁻⁶, respectively. -14 m 3 / N·m.

[0113] Comparative Example 3

[0114] (1) PPS / PTFE fiber fabric (warp density of 326, weft density of 290, and twill weave structure) is woven with PPS fiber and PTFE fiber. After desizing and cleaning with fiber surface oil, it is dried for later use. Subsequently, the fiber fabric is subjected to fiber surface activation treatment in air plasma. The plasma treatment power is 200W and the time is 10min to obtain activated self-lubricating fiber fabric.

[0115] (2) To functionalize h-BN, 0.5 g of h-BN-OH was added to a mixed solution of anhydrous ethanol and deionized water at a volume ratio of 3:1 and sonicated for 60 min to obtain an h-BN-OH dispersion. Then, 6 mL of MPS was added to the h-BN-OH dispersion, and the pH of the solution was adjusted to 4 with acetic acid to further promote hydrolysis. The mixture was refluxed at 80 °C with magnetic stirring for 6 h. Finally, the product was washed several times with anhydrous ethanol and dried at 80 °C to obtain vinyl-functionalized h-BN, named h-BN-MPS.

[0116] (3) The activated self-lubricating fiber fabric was repeatedly impregnated in a phenolic resin solution of h-BN-MPS (the mass fraction of h-BN-MPS relative to phenolic resin was 1 wt%) until the mass fraction of the fabric reached 75 ± 5 wt%, and an uncured PPS / PTFE fiber fabric (h-BN-MPS / FC) was obtained. The fabric was then bonded to the surface of a metal substrate using a phenolic resin adhesive and cured at 184℃ for 2 h to obtain a self-lubricating fiber fabric composite material test piece.

[0117] (4) Under room temperature conditions, with a dynamic load of 30 MPa and a rotation speed of 760 rpm, the friction test lasted for 2 hours. The average coefficient of friction and wear rate of the self-lubricating fabric composite material were 0.0467 and 1.75 × 10⁻⁶, respectively. -14 m 3 / N·m.

[0118] The preparation method of h-BN-OH includes the following steps: 2g of h-BN is placed in a beaker containing 200mL of ethanol and ultrasonically treated at room temperature for 1h to achieve uniform dispersion. Subsequently, 10mL of sulfuric acid (98% by mass) and 30mL of hydrogen peroxide (30% by mass) are added dropwise to the h-BN dispersion at a volume ratio of 1:3. The mixture is continuously stirred at 60℃ for about 12h. After the reaction is completed, the hydroxylated h-BN is collected by centrifugation and washed several times with deionized water and ethanol. Finally, the product is dried at 60℃ for 2h, and the prepared material is labeled as h-BN-OH.

[0119] Comparative Example 4

[0120] (1) PPS / PTFE fiber fabric (warp density of 326, weft density of 290, and twill weave structure) is woven with PPS fiber and PTFE fiber. After desizing and cleaning with fiber surface oil, it is dried for later use. Subsequently, the fiber fabric is subjected to fiber surface activation treatment in air plasma. The plasma treatment power is 200W and the time is 10min to obtain activated self-lubricating fiber fabric.

[0121] (2) The activated self-lubricating fiber fabric was repeatedly impregnated in a phenolic resin solution of Ti3C2 (the mass fraction of Ti3C2 relative to phenolic resin was 1 wt%) until the mass fraction of the fabric reached 75 ± 5 wt%, and an uncured PPS / PTFE fiber fabric (Ti3C2 / FC) was obtained. The fabric was then bonded to the surface of a metal substrate using a phenolic resin adhesive and cured at 184℃ for 2 h to obtain a self-lubricating fiber fabric composite material test piece.

[0122] (3) Under room temperature conditions, with a dynamic load of 30 MPa and a rotation speed of 760 rpm, the friction test lasted for 2 hours. The average coefficient of friction and wear rate of the self-lubricating fabric composite material were 0.0476 and 1.84 × 10⁻⁶, respectively.-14 m 3 / N·m.

[0123] The preparation method of Ti3C2 includes the following steps: 2g of lithium fluoride is placed in 60mL of hydrochloric acid (9mol / L) and stirred for 10min. Then, 2g of Ti3AlC2 is slowly added to the mixed solution, and the mixture is stirred at 45℃ for 36 hours. After the etching reaction is complete, the crude product is centrifuged in deionized water (3500rpm, 3min) until the pH of the supernatant is 7. Then, the lower precipitate is dispersed in deionized water, sonicated, and centrifuged to exfoliate the Ti3C2 nanosheets. Finally, the resulting dark green supernatant is freeze-dried to obtain monolayer and few-layer Ti3C2.

[0124] Comparative Example 5

[0125] (1) PPS / PTFE fiber fabric (warp density of 326, weft density of 290, and twill weave structure) is woven with PPS fiber and PTFE fiber. After desizing and cleaning with fiber surface oil, it is dried for later use. Subsequently, the fiber fabric is subjected to fiber surface activation treatment in air plasma. The plasma treatment power is 200W and the time is 10min to obtain activated self-lubricating fiber fabric.

[0126] (2) To obtain -SH groups on the surface of Ti3C2, Ti3C2 nanosheets (obtained in the same way as Comparative Example 4) were functionalized with MPTEs: In a typical method, 0.5 g of Ti3C2 was added to a mixed solution of anhydrous ethanol and deionized water at a volume ratio of 3:1 and ultrasonically dispersed for 1 h to obtain a Ti3C2 dispersion. Then, 6 mL of MPTEs was added to the Ti3C2 dispersion. To further promote hydrolysis, the pH of the solution was adjusted to 4 with acetic acid. The dispersion was refluxed at 80 °C with magnetic stirring for 6 h. Finally, the product was washed several times with anhydrous ethanol and dried at 80 °C to obtain thiol-functionalized Ti3C2, named MXene-MPTEs.

[0127] (3) The activated self-lubricating fiber fabric was repeatedly impregnated in a phenolic resin solution of Ti3C2-MPTEs (the mass fraction of Ti3C2-MPTEs relative to phenolic resin was 1 wt%) until the mass fraction of the fabric reached 75 ± 5 wt%, and an uncured PPS / PTFE fiber fabric (Ti3C2-MPTEs / FC) was obtained. The fabric was then bonded to the surface of a metal substrate using a phenolic resin adhesive and cured at 184℃ for 2 h to obtain a self-lubricating fiber fabric composite material test piece.

[0128] (4) Under room temperature conditions, with a dynamic load of 30 MPa and a rotation speed of 760 rpm, the friction test lasted for 2 hours. The average coefficient of friction and wear rate of the self-lubricating fabric composite material were 0.0482 and 1.45 × 10⁻⁶, respectively. -14 m 3 / N·m.

[0129] Example 1

[0130] (1) PPS / PTFE fiber fabric (warp density of 326, weft density of 290, and twill weave structure) is woven with PPS fiber and PTFE fiber. After desizing and cleaning with fiber surface oil, it is dried for later use. Subsequently, the fiber fabric is subjected to fiber surface activation treatment in air plasma. The plasma treatment power is 200W and the time is 10min to obtain activated self-lubricating fiber fabric.

[0131] (2) A three-dimensional point-plane structure was constructed by rapidly grafting h-BN onto the MXene surface using a mercapto-ene click reaction.

[0132] First, 0.2 g of MXene-MPTEs (obtained in the same manner as Comparative Example 5) and 0.2 g of h-BN-MPS (obtained in the same manner as Comparative Example 3) were dissolved in 200 mL of DMF and ultrasonically dispersed for 60 min. Then, 0.008 g of AIBN was added to the mixed solution as a thermal initiator for the click reaction, and the mixture was reacted at 80 °C with magnetic stirring for 4 h. Finally, the product was washed with a large amount of anhydrous ethanol to remove ungrafted material, and dried at 80 °C to obtain Ti3C2-h-BN nano-hybrids.

[0133] (3) The activated self-lubricating fiber fabric was repeatedly impregnated in a phenolic resin solution of Ti3C2-h-BN (the mass fraction of Ti3C2-h-BN relative to phenolic resin was 1wt%) until the mass fraction of the fabric reached 75±5wt%, and an uncured PPS / PTFE fiber fabric (Ti3C2-h-BN / FC) was obtained. The fabric was then bonded to the surface of a metal substrate using a phenolic resin adhesive and cured at 184℃ for 2h to obtain a self-lubricating fiber fabric composite material test piece.

[0134] (4) Under room temperature conditions, with a dynamic load of 30 MPa and a rotation speed of 760 r / min, the friction test lasted for 2 hours. The average friction coefficient and wear rate of the self-lubricating fabric composite material were 0.0475 and 1.02 × 10⁻⁶, respectively. -14 m 3 / N·m.

[0135] Figure 1The XRD patterns of h-BN, h-BN-MPS, MXene nanosheets (Ti3C2), MXene-MPTEs (Ti3C2-MPTEs), and MXene-h-BN (Ti3C2-h-BN) are shown below. Figure 1 It can be seen that h-BN exhibits a good crystalline structure and shows obvious characteristic peaks at the (002) and (004) planes. The characteristic peak of MXene at 6.1° corresponds to the (002) crystal plane. For Ti3C2-h-BN, two typical strong diffraction peaks were observed near 6.2° and 27.3°, indicating that h-BN is grafted onto the MXene surface.

[0136] Figure 2 XPS images of h-BN, hydroxylated hexagonal boron nitride (h-BN-OH), MXene nanosheets (Ti3C2), and MXene-h-BN (Ti3C2-h-BN) are shown below. Figure 2 It can be seen that the spectrum of h-BN shows singlets at B1s, N1s, and O1s, with binding energies of 192.3 eV, 396.4 eV, and 524.6 eV, respectively. Ti2p, S2p, and Si2p atoms appear in the Ti3C2-h-BN hybrid. The above characterization analysis confirms the successful preparation of MXene-h-BN nanomaterials with a three-dimensional point-plane structure.

[0137] The tribological properties of the self-lubricating fabric composites obtained in the examples and comparative examples were evaluated using the Xuanwu No. 3 tribological testing machine (contact mode: pin-disc, rotation speed: 760 r / min, load: 30 MPa). The results are as follows: Figure 3 , Figure 3 The data provided are the friction and wear data of the self-lubricating fabric composite materials obtained in the examples and comparative examples, where (a) is the wear rate of the self-lubricating fabric composite materials obtained in the examples and comparative examples, and (b) is the friction coefficient of the self-lubricating fabric composite materials obtained in the examples and comparative examples; Figure 3 As shown, the pure PPS / PTFE self-lubricating material exhibits a relatively high wear rate, while the direct contact between the PTFE fibers and the mating surfaces reduces the coefficient of friction. After adding nanomaterials, the wear rate of the PPS / PTFE self-lubricating material is significantly reduced, with Ti3C2-h-BN / FC showing the lowest wear rate.

[0138] Figure 4 The images show the wear surface morphology of the self-lubricating fabric composite materials obtained in Comparative Example 1 and Example 1, where (a) shows the wear surface morphology of the self-lubricating fabric composite material obtained in Comparative Example 1, and (b) shows the wear surface morphology of the self-lubricating fabric composite material obtained in Example 1; from Figure 4It is clearly visible that the wear surface of pure PPS / PTFE self-lubricating material exhibits numerous cracks, with resin shedding causing many fibers to be pulled out and cut. The primary wear mechanism is abrasive wear. In contrast, Ti3C2-h-BN / FC shows the smoothest wear surface, with the fibers tightly protected by the resin, exhibiting only some wear debris and fine grooves. This indicates that adding MXene-h-BN helps improve the load-bearing capacity of PPS / PTFE self-lubricating fiber fabric composites and increases the resin's shear resistance.

[0139] Figure 5 The tensile strength of the self-lubricating fabric composites obtained in the comparative examples and embodiments is shown. Compared with the pure PPS / PTFE fabric composite (123.42 MPa), the fabric composite with added Ti3C2-h-BN achieved the highest tensile strength of 165.69 MPa, an increase of 34.25%. This indicates that the h-BN particles combined with MXene sheets can form a special three-dimensional point-plane structure, which can be better dispersed in the resin matrix and form a gradient modulus at the resin interface, effectively transferring stress.

[0140] Figure 6 The thermal conductivity of the self-lubricating fabric composites obtained in the comparative examples and embodiments is shown at room temperature and 150°C. Compared with pure FC, the thermal conductivity of the fabric composites with additives is improved. It can be found that the thermal conductivity of the original FC is approximately 0.179 W / m·K at room temperature and approximately 0.201 W / m·K at 150°C. In contrast, Ti3C2-h-BN / FC has the highest thermal conductivity, at 0.286 W / m·K at room temperature and 0.288 W / m·K at 150°C. This result indicates that Ti3C2-h-BN, with its three-dimensional point-plane structure, provides a unique heat transfer network path for phonons and electrons, increasing the phonon velocity and reducing phonon scattering. Furthermore, Ti3C2-h-BN, with its large and unique surface area, can form continuous and interconnected heat conduction channels, playing an important role in reducing interfacial thermal resistance.

[0141] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. The application of MXene-h-BN hybrids in self-lubricating reinforced fabric composites, characterized in that, The preparation method of the MXene-h-BN hybrid includes the following steps: Sulfuric acid, hydrogen peroxide and hexagonal boron nitride are mixed and hydroxylated to obtain hydroxylated hexagonal boron nitride; The hydroxylated hexagonal boron nitride was functionalized using a first silane reagent to obtain functionalized h-BN; the first silane reagent was a silane reagent containing a double bond; MXene nanosheets were obtained by etching Ti3AlC2 using the LiF+HCl system; The MXene nanosheets and the second silane reagent are mixed and subjected to a hydrolysis reaction to obtain silanized MXene; the second silane reagent is a silane reagent containing a thiol group. The silanized MXene and functionalized h-BN were dispersed in a solvent and subjected to a mercapto-alkene click reaction under the action of a thermal initiator to obtain the MXene-h-BN hybrid.

2. The application according to claim 1, characterized in that, The ratio of sulfuric acid, hydrogen peroxide, and hexagonal boron nitride is 5-20 mL: 20-60 mL: 1-8 g; the mass concentration of the sulfuric acid is 60-98%, and the mass concentration of the hydrogen peroxide is 20-30%. The hydroxylation is performed at a temperature of 40-80°C for 6-18 hours. The silane reagents containing double bonds include γ-methacryloxypropyltrimethoxysilane and / or vinyltriethoxysilane; The ratio of the first silane reagent to hydroxylated hexagonal boron nitride is 2~40mL:0.2~6g; The functionalization temperature is 40~200℃, and the time is 4~22h.

3. The application according to claim 1, characterized in that, The silane reagent containing a mercapto group includes γ-mercaptopropyltriethoxysilane and / or γ-mercaptopropyltrimethoxysilane; The ratio of MXene nanosheets to the second silane reagent is 0.4~8g:4~60mL; The hydrolysis reaction is carried out at a temperature of 60~220℃ for a time of 4~22h.

4. The application according to claim 1, characterized in that, The mass ratio of silanized MXene to functionalized h-BN is 0.06~2:0.08~4; The thermal initiator is azobisisobutyronitrile and / or benzoyl peroxide; The mass ratio of silanized MXene to thermal initiator is 0.06~2:0.002~0.8; The click reaction of the mercapto-alkene is carried out at a temperature of 20~160℃ for a time of 2~16h.

5. A self-lubricating reinforced fabric composite material, characterized in that, The raw materials for preparation include: MXene-h-BN hybrid, adhesives, and self-lubricating fiber fabrics; The adhesive is a resin; The self-lubricating fiber fabric is a PPS / PTFE self-lubricating pad material; The mass of the MXene-h-BN hybrid is 0.8-16% of the adhesive mass; The MXene-h-BN hybrid is the MXene-h-BN hybrid used in any one of claims 1 to 4.

6. The self-lubricating reinforced fabric composite material according to claim 5, characterized in that, The resin is one or two of phenolic resin, polyimide resin, epoxy resin and polyamide-imide; The microstructure of the PPS / PTFE self-lubricating pad material is one of plain weave, twill weave, satin weave, or an evolved structure. The PPS / PTFE self-lubricating pad material has a warp density of 240~400 and a weft density of 220~360.

7. The method for preparing the self-lubricating reinforced fabric composite material according to claim 5 or 6, characterized in that, Includes the following steps: The MXene-h-BN hybrid was dispersed in an adhesive to obtain a filler dispersion. Surface activation of self-lubricating fiber fabric was achieved by air plasma etching, resulting in activated self-lubricating fiber fabric. The activated self-lubricating fiber fabric is immersed in the filler dispersion solution, taken out, and cured to obtain the self-lubricating reinforced fabric composite material.

8. The preparation method according to claim 7, characterized in that, The power of the air plasma etching is 40~220W, and the time is 6~40min; The curing temperature is 100~240℃, the pressure is 0.1~1MPa, the time is 80~200min, and the rate of heating to the curing temperature is 2~26℃ / min.

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