An inorganic fiber gasket composite, method of making and use thereof

Abstract

This invention belongs to the field of polymer synthesis and solid lubrication technology, and provides an inorganic fiber liner composite material, its preparation method, and its application. The inorganic fiber liner composite material provided by this invention includes basalt fiber fabric and a polyimide resin composite material incorporating the basalt fiber fabric. The polyimide resin composite material includes polyimide resin and reinforcing filler dispersed in the polyimide resin. The reinforcing filler is a nanodiamond-organically modified montmorillonite hybrid filler. The polyimide resin is prepared from polyamic acid, and the raw materials for preparing the polyamic acid include a diamine monomer, a dianhydride monomer, and a capping agent. The diamine monomer includes 5-amino-2-(4-aminophenyl)benzimidazole and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl. The dianhydride monomer includes 3,3',4,4'-biphenyltetracarboxylic dianhydride. The inorganic fiber liner composite material provided by this invention exhibits excellent high-temperature resistance.

Description

Technical Field

[0001] This invention relates to the fields of polymer synthesis and solid lubrication technology, and in particular to an inorganic fiber liner composite material, its preparation method, and its application. Background Technology

[0002] The tribological properties of self-lubricating fiber-reinforced composite materials are crucial for ensuring the long-term service life of moving parts in aerospace equipment. However, previously reported reinforcement materials primarily consist of woven organic fiber fabrics as the continuous reinforcing phase, such as polyimide fiber fabrics. Nevertheless, the high-temperature resistance of these reinforcement materials needs further improvement. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide an inorganic fiber liner composite material, its preparation method, and its application. The inorganic fiber liner composite material provided by this invention has excellent high-temperature resistance and can withstand temperatures up to 430°C.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an inorganic fiber liner composite material, comprising basalt fiber fabric and a polyimide resin composite material incorporated in the basalt fiber fabric; The polyimide resin composite material includes polyimide resin and reinforcing filler dispersed in the polyimide resin, wherein the reinforcing filler is a nanodiamond-organic modified montmorillonite hybrid filler; The polyimide resin is prepared from polyamic acid, and the raw materials for preparing the polyamic acid include diamine monomer, dianhydride monomer and end-capping agent; The diamine monomers include 5-amino-2-(4-aminophenyl)benzimidazole (DAPBI) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB). The dianhydride monomer includes 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA).

[0005] Preferably, the nanodiamond-organically modified montmorillonite hybrid filler is composed of nanodiamond and organically modified montmorillonite, and the mass ratio of nanodiamond to organically modified montmorillonite is 0.5~1:0.5~1.

[0006] Preferably, the preparation method of the nanodiamond-organic modified montmorillonite hybrid filler includes the following steps: Organically modified montmorillonite, nanodiamond, and water are mixed and composited to obtain the nanodiamond-organically modified montmorillonite hybrid filler. The compounding time is 8-12 hours.

[0007] Preferably, the method for preparing the organically modified montmorillonite includes the following steps: Montmorillonite, an intercalating agent, and water were mixed and modified to obtain organically modified montmorillonite. The intercalating agent comprises octadecyl dimethyl benzyl ammonium chloride; The mass ratio of montmorillonite to intercalating agent is 10:4~5, and the modification temperature is 50~100℃, with a time of 4~8h.

[0008] Preferably, the capping agent comprises 5-norbornene-2,3-dicarboxylic anhydride (NA). The molar ratio of 5-amino-2-(4-aminophenyl)benzimidazole (DAPBI) to 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB) is 2:8 to 4:6. The molar ratio of the diamine monomer, dianhydride monomer, and capping agent is (n+1):n:2, where n is 2 to 3.

[0009] Preferably, the method for preparing the polyamic acid includes the following steps: A diamine monomer and an organic solvent are mixed, a dianhydride monomer is added to carry out a polymerization reaction, and then a capping agent is added to carry out a capping reaction to obtain the polyamic acid; The polymerization reaction takes 4-6 hours; The capping reaction takes 10-16 hours.

[0010] This invention also provides a method for preparing the inorganic fiber liner composite material described in the above technical solution, comprising the following steps: Polyamic acid, reinforcing filler, and solvent are mixed to obtain an impregnation solution; After repeatedly impregnating and drying the basalt fiber fabric in the impregnation solution, a fabric prepreg is obtained; The fabric prepreg is cured to obtain the inorganic fiber liner composite material.

[0011] Preferably, the total mass fraction of polyamic acid and reinforcing fillers in the fabric prepreg is 15-40%; The mass of the reinforcing filler is 0.5 to 2% of the mass of the polyimide.

[0012] Preferably, the curing process is as follows: The temperature is first increased from room temperature to a first temperature and then kept warm for a first time; the first temperature is 90~110℃ and the first holding time is 180~240min. The temperature is raised from the first temperature to a second temperature and then kept warm for a second time; the second temperature is 190~210℃ and the second holding time is 30~60min. The temperature is raised from the second temperature to a third temperature and then held for a third time; the third temperature is 240~260℃ and the third holding time is 30~60min. The temperature is increased from the third temperature to the fourth temperature and then maintained for a fourth time; the fourth temperature is 290~310℃ and the fourth maintenance time is 30~60min. The temperature is increased from the fourth temperature to the fifth temperature and then kept warm for a fifth time. The fifth temperature is 340~360℃ and the fifth holding time is 30~60min.

[0013] The present invention also provides the application of the inorganic fiber liner composite material described in the above technical solution or the inorganic fiber liner composite material prepared by the preparation method described in the above technical solution in the actuating parts of aerospace equipment.

[0014] This invention provides an inorganic fiber liner composite material.

[0015] This invention uses basalt fiber fabric as a continuous reinforcing phase, combined with high-temperature resistant polyimide resin and nanodiamond-organically modified montmorillonite hybrid filler as the reinforcing material, to obtain a high-temperature resistant and low-wear liner composite material. The basalt fiber fabric used in this invention is an inorganic fabric, which is more heat-resistant than organic fiber polyimide fiber fabric. 5-amino-2-(4-aminophenyl)benzimidazole and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl are used as diamine monomers, and 3,3',4,4'-biphenyltetracarboxylic dianhydride is used as a dianhydride monomer. Through cross-linking and curing, a three-dimensional network is formed, improving the heat resistance and mechanical strength of the polyimide resin matrix. Furthermore, the nanodiamond-organically modified montmorillonite hybrid filler is embedded into the polyimide resin matrix molecular chain through in-situ curing, increasing the degree of cross-linking of the polyimide resin matrix and improving the mechanical properties and thermal stability of the liner composite material. Meanwhile, during high-temperature friction, the introduced nanodiamond-organic modified montmorillonite hybrid filler in the inorganic fiber liner composite material can improve the high-temperature load-bearing capacity of the liner composite material and participate in the construction of a high-quality friction transfer film, thereby enhancing the high-temperature tribological properties of the liner composite material. Furthermore, the basalt fiber fabric of this invention is lower in cost than existing polyimide fiber fabrics, making it more suitable for widespread application. Attached Figure Description

[0016] Figure 1 The graph shows the wear rate and coefficient of friction of the inorganic fiber fabric padding materials prepared in Comparative Example 1 and Example 1. Figure 1 In the figure, (a) is a comparison chart of friction coefficients, and (b) is a comparison chart of wear rates; Figure 2 The diagram shows the reaction mechanism of polyamic acid preparation and polyamic acid curing and crosslinking to form polyimide resin in Example 1. Detailed Implementation

[0017] This invention provides an inorganic fiber liner composite material, comprising basalt fiber fabric and a polyimide resin composite material incorporated in the basalt fiber fabric; The polyimide resin composite material includes polyimide resin and reinforcing filler dispersed in the polyimide resin, wherein the reinforcing filler is a nanodiamond-organic modified montmorillonite hybrid filler; The polyimide resin is prepared from polyamic acid, and the raw materials for preparing the polyamic acid include diamine monomer, dianhydride monomer and end-capping agent; The diamine monomers include 5-amino-2-(4-aminophenyl)benzimidazole (DAPBI) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB). The dianhydride monomer includes 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA).

[0018] The inorganic fiber lining composite material provided by this invention includes basalt fiber fabric. In this invention, the fineness of the basalt fibers used in the basalt fiber fabric is preferably 250-300D. In this invention, the weave structure of the basalt fiber fabric is preferably one or more of plain weave, twill weave, and satin weave; when the weave structure of the basalt fiber fabric is one or more of the above, this invention does not have a special limitation on the distribution ratio and method of different weave structures, and any ratio or method is acceptable. This invention does not have a special limitation on the specific weaving process of the basalt fiber fabric; it can be woven according to processes well known in the art. This invention uses basalt fiber fabric as the reinforcing continuous phase. Compared with organic fiber fabrics and polyimide fiber fabrics, basalt fiber fabric, as an inorganic material, is more resistant to high temperatures, its mechanical properties are not damaged under high-temperature conditions, and it also has excellent wear resistance; in addition, the cost is lower.

[0019] The inorganic fiber liner composite material provided by this invention includes a polyimide resin composite material incorporated in basalt fiber fabric. In this invention, the polyimide resin composite material comprises polyimide resin and reinforcing filler dispersed in the polyimide resin, wherein the reinforcing filler is a nanodiamond-organic modified montmorillonite hybrid filler. Preferably, the nanodiamond-organic modified montmorillonite hybrid filler is composed of nanodiamond and organic modified montmorillonite, and the mass ratio of nanodiamond to organic modified montmorillonite is preferably 0.5~1:0.5~1, specifically preferably 1:1. This invention introduces the nanodiamond-organic modified montmorillonite hybrid filler into the inorganic fiber fabric liner composite material. By leveraging the synergistic reinforcing effect of nanodiamond and organic modified montmorillonite filler, the heat resistance of the polyimide resin matrix is ​​further improved, and the filler participates in the high-temperature friction and wear process, ultimately achieving long-term and stable operation of the inorganic fiber liner composite material under high-temperature conditions.

[0020] In this invention, the preparation method of the nanodiamond-organically modified montmorillonite hybrid filler preferably includes the following steps: mixing organically modified montmorillonite, nanodiamond, and water, and compounding them to obtain the nanodiamond-organically modified montmorillonite hybrid filler. In this invention, the compounding temperature is preferably room temperature, i.e., neither additional heating nor additional cooling is required; the compounding time is preferably 8-12 hours; the compounding is preferably carried out under stirring conditions; after the compounding is completed, this invention preferably further includes: filtering the obtained composite liquid to obtain a solid, and drying the solid to obtain the nanodiamond-organically modified montmorillonite hybrid filler. In this invention, the preparation method of the organically modified montmorillonite preferably includes the following steps: mixing montmorillonite, an intercalating agent, and water, and modifying them to obtain organically modified montmorillonite. In this invention, the intercalating agent preferably comprises octadecyl dimethyl benzyl ammonium chloride; the montmorillonite is preferably sodium montmorillonite; the mass ratio of montmorillonite to intercalating agent is preferably 10:4~5, more preferably 10:4.7; the modification of montmorillonite, intercalating agent and water preferably includes the following steps: dispersing montmorillonite in water to form a montmorillonite dispersion; mixing the intercalating agent and water to obtain an intercalating agent solution; and adding the intercalating agent solution dropwise to the montmorillonite dispersion for modification. In this invention, the modification temperature is preferably 50~100℃, specifically preferably 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, or 100℃; the time is preferably 4~8h, specifically preferably 6h; the modification is preferably carried out under stirring conditions; after modification, this invention preferably further includes: filtering the obtained modified liquid, washing and drying the obtained solid sequentially to obtain the organically modified montmorillonite. The nanodiamond-organically modified montmorillonite hybrid filler provided by this invention is obtained by in-situ loading nanodiamonds onto the surface of organically modified montmorillonite nanosheets. In this invention, montmorillonite is modified into montmorillonite nanosheets through intercalation and combined with diamond nanoparticles through electrostatic adsorption, which plays a certain role in inhibiting the aggregation of nanodiamonds. The organically modified montmorillonite has a layered structure, which can provide load-bearing and interlayer slippage during the friction process of the pad composite material. Diamond nanoparticles are hard nanomaterials that improve the high-temperature load-bearing capacity of gasket composites during high-temperature friction. Furthermore, nanodiamonds possess excellent thermal conductivity, effectively mitigating frictional heat at the friction interface and participating in tribochemical reactions at the interface, thus achieving a synergistic enhancement of the high-temperature tribological properties of the gasket composite.

[0021] In this invention, the polyimide resin is prepared from polyamic acid, and the raw materials for preparing the polyamic acid include a diamine monomer, a dianhydride monomer, and a capping agent. In this invention, the diamine monomer includes 5-amino-2-(4-aminophenyl)benzimidazole (DAPBI) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB); the molar ratio of 5-amino-2-(4-aminophenyl)benzimidazole (DAPBI) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB) is preferably 2:8 to 4:6, more preferably 3:7. In this invention, the dianhydride monomer includes 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA). In this invention, the capping agent includes 5-norbornene-2,3-dicarboxylic anhydride (NA). In this invention, the molar ratio of the diamine monomer, dianhydride monomer, and capping agent is preferably (n+1):n:2; where n is preferably 2 to 3, specifically 2 or 3; that is, the molar ratio of the diamine monomer, dianhydride monomer, and capping agent is specifically preferably 3:2:2 or 4:31:2. The polyimide resin of this invention uses DAPBI and TFMB as diamine monomers and 3,3',4,4'-biphenyltetracarboxylic dianhydride (s-BPDA) as a dianhydride monomer; DAPBI contains a benzimidazole group, TFMB contains a trifluoromethyl group, and the s-BPDA molecule contains a rigid group. These groups and structures can effectively improve the high-temperature stability of the final polyimide molecular chain.

[0022] In this invention, the method for preparing the polyamic acid preferably includes the following steps: A diamine monomer and an organic solvent are mixed, a dianhydride monomer is added to carry out a polymerization reaction, and then a capping agent is added to carry out a capping reaction to obtain the polyamic acid. In this invention, the organic solvent preferably includes N-methylpyrrolidone (NMP). In this invention, the ratio of the diamine monomer to the organic solvent is preferably 12 mmol:15 mL. In this invention, the polymerization reaction temperature is preferably room temperature, the time is preferably 4-6 h, the polymerization reaction is preferably carried out under a protective atmosphere, preferably nitrogen; the polymerization reaction is preferably carried out under stirring. In this invention, the capping reaction temperature is preferably room temperature, the time is preferably 10-16 h, specifically preferably 12 h; the capping reaction is preferably carried out under a protective atmosphere, preferably nitrogen; the capping reaction is preferably carried out under stirring.

[0023] In this invention, the polyamic acid is preferably used in the form of a polyamic acid solution.

[0024] In this invention, the polyamic acid is cured to form a polyimide resin with a three-dimensional network structure; the formed polyimide resin has excellent high-temperature mechanical and wear-resistant properties.

[0025] This invention also provides a method for preparing the inorganic fiber liner composite material described in the above technical solution, comprising the following steps: Polyamic acid, reinforcing filler, and solvent are mixed to obtain an impregnation solution; After repeatedly impregnating and drying the basalt fiber fabric in the impregnation solution, a fabric prepreg is obtained; The fabric prepreg is cured to obtain the inorganic fiber liner composite material.

[0026] This invention mixes polyamic acid, reinforcing filler, and solvent to obtain an impregnation solution. In this invention, the solvent preferably includes N-methylpyrrolidone (NMP). In this invention, the mass of the reinforcing filler is preferably 0.5-2% of the mass of the polyimide, specifically preferably 0.5%, 1%, 1.5%, or 2%; when the polyimide is preferably a polyimide solution, the mass of the reinforcing material is preferably 0.5-2% of the mass of the polyimide solution. In this invention, mixing the polyamic acid, reinforcing filler, and solvent preferably includes the following steps: mixing the polyamic acid and solvent to obtain a diluted polyamic acid solution; and mixing the diluted polyamic acid solution with the reinforcing filler to obtain the impregnation solution. In this invention, the concentration of the polyamic acid diluent is preferably 0.1~0.3 g / mL, more preferably 0.10~0.25 g / mL; when the polyamic acid is preferably used in the form of a polyamic acid solution, the concentration of the polyamic acid diluent of 0.1~0.3 g / mL means that the concentration of the polyamic acid solution in the polyamic acid diluent is 0.1~0.3 g / mL.

[0027] After obtaining the impregnation solution, the basalt fiber fabric is repeatedly impregnated and dried in the impregnation solution to obtain a fabric prepreg. In this invention, the basalt fiber fabric is preferably pretreated before use; the pretreatment preferably includes the following steps: air plasma treatment of the basalt fiber fabric; the power of the air plasma treatment is preferably 40-300W, more preferably 100-250W, and the time is preferably 5-30min, more preferably 10-20min. In this invention, the air plasma treatment etches the fiber surface of the basalt fiber fabric, introducing active functional groups onto the fiber surface, thereby enabling chemical bonding between the basalt fiber fabric and the polyimide resin during impregnation, enhancing the interfacial bonding between the basalt fiber fabric and the polyimide resin, and thus enhancing the tribological properties of the inorganic fiber pad composite material.

[0028] This invention does not specifically limit the impregnation and drying process; impregnation and drying can be carried out according to processes well known in the art to obtain the fabric prepreg. In embodiments of this invention, the drying method is specifically oven drying.

[0029] In this invention, the total mass fraction of polyamic acid and reinforcing filler in the fabric prepreg is preferably 15-40%, more preferably 20-30%, and specifically preferably 15%, 20%, 25%, 30%, 35%, or 40%. In this invention, the total mass fraction of polyamic acid and reinforcing filler in the fabric prepreg of 15-40% also refers to the amount of adhesive applied; simultaneously, when the total mass fraction of polyamic acid and reinforcing filler in the fabric prepreg is 15-40%, it also represents that the mass fraction of basalt fiber fabric in the fabric prepreg is 60-85%.

[0030] In this invention, the repeated impregnation and drying are performed until the sum of the mass of polyamic acid and reinforcing filler accounts for 15-40% of the mass of the fabric prepreg (i.e., the amount of adhesive applied). After impregnation and drying, the mixture of polyamic acid and reinforcing filler is coated on the surface of the basalt fiber fabric as a continuous phase of the inorganic fiber padding composite material.

[0031] After obtaining the fabric prepreg, the present invention cures the fabric prepreg to obtain the inorganic fiber pad composite material.

[0032] In this invention, the curing process is as follows: The temperature is first increased from room temperature to a first temperature, followed by a first heat preservation process. The temperature is raised from the first temperature to a second temperature for a second heat preservation process. The temperature is raised from the second temperature to the third temperature for a third heat preservation process; The temperature is increased from the third temperature to the fourth temperature for a fourth heat preservation. The temperature is increased from the fourth temperature to the fifth temperature for the fifth heat preservation.

[0033] In this invention, the first temperature is preferably 90~110℃, more preferably 100℃, the first holding time is preferably 180~240min, and the first heating rate is preferably 3~10℃ / min, more preferably 5~8℃ / min.

[0034] In this invention, the second temperature is preferably 190~210℃, more preferably 200℃, the second holding time is preferably 30~60min; the second heating rate is preferably 3~10℃ / min, more preferably 5~8℃ / min; In this invention, the third temperature is preferably 240~260℃, more preferably 250℃; the third holding time is preferably 30~60min; and the third heating rate is preferably 3~10℃ / min, more preferably 5~8℃ / min.

[0035] In this invention, the fourth temperature is preferably 290~310℃, more preferably 300℃; the fourth holding time is preferably 30~60min; and the fourth heating rate is preferably 3~10℃ / min, more preferably 5~8℃ / min.

[0036] In this invention, the fifth temperature is preferably 340~360℃, more preferably 350℃, the fifth holding time is preferably 30~60min, and the fifth heating rate is preferably 3~10℃ / min, more preferably 5~8℃ / min.

[0037] In this invention, the curing pressure is preferably 0.01~3MPa, more preferably 0.2~2.5MPa.

[0038] This invention uses curing to further crosslink and cure the polyamic acid in the fabric prepreg, constructing a three-dimensional network structure, so that the final polyimide resin matrix has excellent high-temperature mechanical and wear-resistant properties.

[0039] The present invention also provides the application of the inorganic fiber liner composite material described in the above technical solution or the inorganic fiber liner composite material prepared by the preparation method described in the above technical solution in the actuating parts of aerospace equipment.

[0040] The present invention does not specifically limit the application of the inorganic fiber liner composite material; any operation known to those skilled in the art can be used.

[0041] The inorganic fiber liner composite material, its preparation method, and its application provided by the present invention will be described in detail below with reference to the embodiments. However, these should not be construed as limiting the scope of protection of the present invention.

[0042] Example 1 Preparation of polyamic acid solution: 3.60 mmol DAPBI and 8.40 mmol TFMB diamine monomer were mixed and dissolved in 15 mL N-methylpyrrolidone. Then, 8 mmol s-BPDA dianhydride monomer was added to the solution. The mixture was reacted at room temperature for 4 h under nitrogen protection. Then, 8 mmol NA end-capping agent was added and the reaction was carried out for 12 h to obtain polyamic acid solution.

[0043] Preparation of reinforced filler: Organically modified montmorillonite was prepared by intercalation modification of sodium-based montmorillonite using octadecyl dimethyl benzyl ammonium chloride: 10g of montmorillonite was dispersed in 300mL of deionized water to form a stable montmorillonite dispersion; simultaneously, 4.7g of intercalating agent was dissolved in 100mL of deionized water to form an intercalating agent solution; then the intercalating agent solution was added dropwise to the montmorillonite dispersion, and the two were stirred and reacted at 75℃ for 6h, followed by filtration, washing, and drying to obtain organically modified montmorillonite; subsequently, organically modified montmorillonite and nanodiamond were stirred and reacted in water at a mass ratio of 1:1 at room temperature for 12h, followed by filtration and drying to obtain nanodiamond-organically modified montmorillonite hybrid filler.

[0044] 5g of the above polyamic acid solution was dispersed in 25mL of NMP solvent to obtain a polyamic acid dilution; the above polyamic acid dilution was mixed with 0.1g of nanodiamond-organic modified montmorillonite hybrid reinforcing filler, the mass of the reinforcing filler being 2% of the mass of the polyimide solution, to obtain an impregnation solution.

[0045] Basalt fiber fabric was obtained by plain weaving and then subjected to air plasma modification treatment at 100W for 10 minutes. The resulting basalt fiber fabric was repeatedly impregnated and dried in the above impregnation solution until the total mass fraction of polyamic acid and reinforcing filler in the resulting fabric prepreg reached 30%, thus obtaining the fabric prepreg.

[0046] The fabric prepreg was bonded to the surface of a 17-4PH metal substrate using polyamic acid resin. The temperature was increased from room temperature (5℃ / min) to 100℃ and held for 180 min; then increased to 200℃ (5℃ / min) and held for 30 min; then increased to 250℃ (5℃ / min) and held for 30 min; then increased to 300℃ (5℃ / min) and held for 30 min; and finally increased to 350℃ (5℃ / min) and held for 60 min. During the programmed temperature increase, the pressure was controlled at 0.5 MPa to obtain an inorganic fiber pad composite material with hybrid filler synergistic reinforcement of high-temperature resistant inorganic fiber fabric.

[0047] Example 2 Preparation of polyamic acid solution: 3.60 mmol DAPBI and 8.40 mmol TFMB diamine monomer were mixed and dissolved in 15 mL N-methylpyrrolidone solution. Then, 9 mmol s-BPDA dianhydride monomer was added to the solution. The mixture was reacted at room temperature for 4 h under a nitrogen atmosphere. Then, 6 mmol NA end-capping agent was added and the reaction was carried out for 12 h to obtain polyamic acid solution.

[0048] Preparation of reinforced filler: Organically modified montmorillonite was prepared by intercalation modification of sodium-based montmorillonite using octadecyl dimethyl benzyl ammonium chloride: 10g of montmorillonite was dispersed in 300mL of deionized water to form a stable montmorillonite dispersion; simultaneously, 4.7g of intercalating agent was dissolved in 100mL of deionized water to form an intercalating agent solution; then the intercalating agent solution was added dropwise to the montmorillonite dispersion, and the two were stirred and reacted at 75℃ for 6h, followed by filtration, washing, and drying to obtain organically modified montmorillonite; subsequently, organically modified montmorillonite and nanodiamond were stirred and reacted in an aqueous solution at a mass ratio of 1:1 at room temperature for 12h, followed by filtration and drying to obtain nanodiamond-organically modified montmorillonite hybrid filler.

[0049] 5g of the above polyamic acid solution was dispersed in 25mL of NMP solvent to obtain a polyamic acid dilution; the above polyamic acid dilution was mixed with 0.1g of nanodiamond-organic modified montmorillonite hybrid reinforcing filler, the mass of the reinforcing filler being 2% of the mass of the polyimide solution, to obtain an impregnation solution.

[0050] Basalt fiber fabric is obtained by plain weaving. It is then subjected to air plasma modification treatment at 100W for 10 minutes. The resulting basalt fiber fabric is repeatedly impregnated and dried in the impregnation solution until the mass fraction of polyamic acid and reinforcing filler in the resulting fabric prepreg reaches 30%, thus obtaining the fabric prepreg.

[0051] The fabric prepreg was bonded to the surface of a 17-4PH metal substrate using polyamic acid resin. The temperature was increased from room temperature (5℃ / min) to 100℃ and held for 180 min; then increased to 200℃ (5℃ / min) and held for 30 min; then increased to 250℃ (5℃ / min) and held for 30 min; then increased to 300℃ (5℃ / min) and held for 30 min; and finally increased to 350℃ (5℃ / min) and held for 60 min. The pressure was controlled at 0.5 MPa during the temperature program, resulting in an inorganic fiber pad composite material with hybrid filler synergistic reinforcement of high-temperature resistant inorganic fiber fabric.

[0052] Example 3 Preparation of polyamic acid solution: 3.60 mmol DAPBI and 8.40 mmol TFMB diamine monomer were mixed and dissolved in 15 mL N-methylpyrrolidone. 8 mmol s-BPDA dianhydride monomer was added to the solution. The mixture was reacted at room temperature for 4 h under a nitrogen atmosphere. Then 8 mmol NA end-capping agent was added and the reaction was carried out for 12 h to obtain polyamic acid solution.

[0053] Preparation of reinforced filler: Organically modified montmorillonite was prepared by intercalation modification of sodium-based montmorillonite using octadecyl dimethyl benzyl ammonium chloride: 10g of montmorillonite was dispersed in 300mL of deionized water to form a stable montmorillonite dispersion; simultaneously, 4.7g of intercalating agent was dissolved in 100mL of deionized water to form an intercalating agent solution; then the intercalating agent solution was added dropwise to the montmorillonite dispersion, and the two were stirred and reacted at 75℃ for 6h, followed by filtration, washing, and drying to obtain organically modified montmorillonite; subsequently, organically modified montmorillonite and nanodiamond were stirred and reacted in an aqueous solution at a mass ratio of 1:1 at room temperature for 12h, followed by filtration and drying to obtain nanodiamond-organically modified montmorillonite hybrid filler.

[0054] 5g of the above polyamic acid solution was dispersed in 25mL of NMP solvent to obtain a polyamic acid dilution; the above polyamic acid dilution was mixed with 0.05g of nanodiamond / organic modified montmorillonite hybrid reinforcing filler, the mass of the reinforcing filler being 1% of the mass of the polyimide solution, to obtain an impregnation solution.

[0055] Basalt fiber fabric is obtained by plain weaving. It is then subjected to air plasma modification treatment at 100W for 10 minutes. The resulting basalt fiber fabric is repeatedly impregnated and dried in the impregnation solution until the mass fraction of polyamic acid resin and reinforcing filler in the resulting fabric prepreg reaches 30%, thus obtaining the fabric prepreg.

[0056] The fabric prepreg was bonded to the surface of a 17-4PH metal substrate using polyamic acid resin. The temperature was increased from room temperature (5℃ / min) to 100℃ and held for 180 min; then increased to 200℃ (5℃ / min) and held for 30 min; then increased to 250℃ (5℃ / min) and held for 30 min; then increased to 300℃ (5℃ / min) and held for 30 min; and finally increased to 350℃ (5℃ / min) and held for 60 min. The temperature was controlled at 0.5 MPa during the programmed temperature increase process to obtain an inorganic fiber pad composite material with hybrid filler synergistic reinforcement of high-temperature resistant inorganic fiber fabric.

[0057] Example 4 Preparation of polyamic acid solution: 3.60 mmol DAPBI and 8.40 mmol TFMB diamine monomer were mixed and dissolved in 15 mL N-methylpyrrolidone solution. Then, 8 mmol s-BPDA dianhydride monomer was added to the solution. The mixture was reacted at room temperature for 4 h under a nitrogen atmosphere. Then, 8 mmol NA end-capping agent was added and the reaction was carried out for 12 h to obtain polyamic acid solution.

[0058] Preparation of reinforced filler: Organically modified montmorillonite was prepared by intercalation modification of sodium-based montmorillonite using octadecyl dimethyl benzyl ammonium chloride: 10g of montmorillonite was dispersed in 300mL of deionized water to form a stable montmorillonite dispersion; simultaneously, 4.7g of intercalating agent was dissolved in 100mL of deionized water to form an intercalating agent solution; then the intercalating agent solution was added dropwise to the montmorillonite dispersion, and the two were stirred and reacted at 75℃ for 6h, followed by filtration, washing, and drying to obtain organically modified montmorillonite; subsequently, organically modified montmorillonite and nanodiamond were stirred and reacted in an aqueous solution at a mass ratio of 1:1 at room temperature for 12h, followed by filtration and drying to obtain nanodiamond-organically modified montmorillonite hybrid filler.

[0059] 5g of the above polyamic acid solution was dispersed in 25mL of NMP solvent to obtain a polyamic acid dilution; the above polyamic acid dilution was mixed with 0.1g of nanodiamond-organic modified montmorillonite hybrid reinforcing filler, the mass of the reinforcing filler being 2% of the mass of the polyimide solution, to obtain an impregnation solution.

[0060] Basalt fiber fabric is obtained by plain weaving. It is then subjected to air plasma modification treatment at 100W for 10 minutes. The resulting basalt fiber fabric is repeatedly impregnated and dried in the impregnation solution until the mass fraction of polyamic acid resin and reinforcing filler in the resulting fabric prepreg reaches 20%.

[0061] The fabric prepreg was bonded to the surface of a 17-4PH metal substrate using polyamic acid resin. The temperature was increased from room temperature (5℃ / min) to 100℃ and held for 180 min; then increased to 200℃ (5℃ / min) and held for 30 min; then increased to 250℃ (5℃ / min) and held for 30 min; then increased to 300℃ (5℃ / min) and held for 30 min; and finally increased to 350℃ (5℃ / min) and held for 60 min. The pressure was controlled at 0.5 MPa during the temperature program, resulting in an inorganic fiber pad composite material with hybrid filler synergistic reinforcement of high-temperature resistant inorganic fiber fabric.

[0062] Comparative Example 1 The only difference from Example 1 is that no reinforcing filler was added to the polyamic acid dilution solution, and an inorganic fiber fabric liner composite material without reinforcing filler was prepared.

[0063] Comparative Example 2 The only difference from Example 1 is that nanodiamonds are added only to the polyamic acid dilution solution to prepare an inorganic fiber fabric liner composite material reinforced with nanodiamond filler.

[0064] Comparative Example 3 The only difference from Example 1 is that organically modified montmorillonite nanosheets are added only to the polyamic acid dilution solution to prepare an inorganic fiber fabric liner composite material reinforced with organically modified montmorillonite nanosheet filler.

[0065] Comparative Example 4 The only difference from Example 1 is that DAPBI is replaced with TFMB in the preparation of the polyamic acid solution; otherwise, it is the same as Example 1.

[0066] Comparative Example 5 The only difference from Example 1 is that TFMB is replaced with DAPBI in the preparation of the polyamic acid solution; otherwise, it is the same as Example 1.

[0067] Comparative Example 6 The only difference from Example 1 is that TFMB and DAPBI are replaced with APBIA diamine in the preparation of the polyamic acid solution; otherwise, they are the same as in Example 1.

[0068] Comparative Example 7 The only difference from Example 1 is that 0.1g of nanodiamond-organic modified montmorillonite hybrid reinforcing filler is replaced with 0.05g of boron nitride and 0.05g of titanium boride.

[0069] Performance testing 1) The high-temperature tribological properties of the hybrid filler-reinforced inorganic fiber fabric pad composites prepared in Examples 1-4 and the inorganic fiber fabric pad materials in Comparative Examples 1-7 were tested. The test conditions were: pressure 2 N, sliding friction speed 500 r / min (rotation radius 5 mm), time 30 min, and temperature 430 °C. A ball-disc tribological testing machine was used, with a 6 mm diameter Gr15 steel ball as the friction pair. The friction coefficient was automatically output after the collected data were processed by a connected computer. The wear width of the self-lubricating fabric pad material was measured using an optical microscope, and the wear volume of the fabric pad material was calculated using Formulas 1 and 2. The test results are shown in Table 1.

[0070] Formula 1; Formula 2 Where R is the dual diameter (mm), b is the wear mark width (mm), and d is the dual rotation diameter (mm). Wear volume (mm) 3 P is the applied load (N), L is the total sliding distance (m), and Ws is the wear rate (mm). 3 / N·m).

[0071] Table 1. Inorganic fiber fabric padding materials prepared in Examples 1-4 and Comparative Examples 1-3 Friction and wear data

[0072] As shown in Table 1, the wear rate and friction coefficient of the inorganic fiber liner composite material prepared in Example 1 are 1.27 × 10⁻⁶. -4 m 3 (Nm) -1 The values ​​of 0.32 and 0.32 were reduced by 47.5% and 74.2% respectively compared to Comparative Example 1, achieving a significant improvement in the high-temperature wear resistance and lubrication performance of inorganic fiber fabric pads.

[0073] Figure 1 The graphs show the wear rate and coefficient of friction of the inorganic fiber fabric padding materials prepared in Comparative Example 1 and Example 1, where (a) is a comparison graph of the coefficient of friction and (b) is a comparison graph of the wear rate. Figure 1 It can be seen that after the inorganic fiber fabric liner is reinforced with nanodiamond-organic modified montmorillonite hybrid reinforcing filler, the high-temperature friction and wear performance of the liner material is significantly improved.

[0074] Figure 2 The diagram shows the reaction mechanism of the polyamic acid prepared in Example 1 and the subsequent curing and crosslinking of the polyamic acid to form thermosetting polyimide.

[0075] 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. An inorganic fiber liner composite material, characterized in that, Including basalt fiber fabric and polyimide resin composite material compounded in the basalt fiber fabric; The polyimide resin composite material includes polyimide resin and reinforcing filler dispersed in the polyimide resin, wherein the reinforcing filler is a nanodiamond-organic modified montmorillonite hybrid filler; The polyimide resin is prepared from polyamic acid, and the raw materials for preparing the polyamic acid include diamine monomer, dianhydride monomer and end-capping agent; The diamine monomers include 5-amino-2-(4-aminophenyl)benzimidazole and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl; The dianhydride monomer includes 3,3',4,4'-biphenyltetracarboxylic dianhydride.

2. The inorganic fiber liner composite material according to claim 1, characterized in that, The nanodiamond-organic modified montmorillonite hybrid filler is composed of nanodiamond and organic modified montmorillonite, and the mass ratio of nanodiamond to organic modified montmorillonite is 0.5~1:0.5~1.

3. The inorganic fiber liner composite material according to claim 1 or 2, characterized in that, The preparation method of the nanodiamond-organically modified montmorillonite hybrid filler includes the following steps: Organically modified montmorillonite, nanodiamond, and water are mixed and composited to obtain the nanodiamond-organically modified montmorillonite hybrid filler. The compounding time is 8-12 hours.

4. The inorganic fiber liner composite material according to claim 2, characterized in that, The preparation method of the organically modified montmorillonite includes the following steps: Montmorillonite, an intercalating agent, and water were mixed and modified to obtain organically modified montmorillonite. The intercalating agent comprises octadecyl dimethyl benzyl ammonium chloride; The mass ratio of montmorillonite to intercalating agent is 10:4~5, and the modification temperature is 50~100℃, with a time of 4~8h.

5. The inorganic fiber liner composite material according to claim 1, characterized in that, The capping agent includes 5-norbornene-2,3-dicarboxylic anhydride; The molar ratio of 5-amino-2-(4-aminophenyl)benzimidazole to 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl is 2:8 to 4:

6. The molar ratio of the diamine monomer, dianhydride monomer, and capping agent is (n+1):n:2, where n is 2 to 3.

6. The inorganic fiber liner composite material according to claim 1 or 5, characterized in that, The preparation method of the polyamic acid includes the following steps: A diamine monomer and an organic solvent are mixed, a dianhydride monomer is added to carry out a polymerization reaction, and then a capping agent is added to carry out a capping reaction to obtain the polyamic acid; The polymerization reaction takes 4-6 hours; The capping reaction takes 10-16 hours.

7. The method for preparing the inorganic fiber liner composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: Polyamic acid, reinforcing filler, and solvent are mixed to obtain an impregnation solution; After repeatedly impregnating and drying the basalt fiber fabric in the impregnation solution, a fabric prepreg is obtained; The fabric prepreg is cured to obtain the inorganic fiber liner composite material.

8. The preparation method according to claim 7, characterized in that, The total mass fraction of polyamic acid and reinforcing fillers in the fabric prepreg is 15-40%; The mass of the reinforcing filler is 0.5 to 2% of the mass of the polyimide.

9. The preparation method according to claim 7, characterized in that, The curing process is as follows: The temperature is first increased from room temperature to a first temperature and then kept warm for a first time; the first temperature is 90~110℃ and the first holding time is 180~240min. The temperature is raised from the first temperature to a second temperature for a second heat preservation process. The second temperature is 190~210℃, and the second heat preservation time is 30~60min; The temperature is raised from the second temperature to a third temperature and then held for a third time; the third temperature is 240~260℃ and the third holding time is 30~60min. The temperature is increased from the third temperature to the fourth temperature and then maintained for a fourth time; the fourth temperature is 290~310℃ and the fourth maintenance time is 30~60min. The temperature is increased from the fourth temperature to the fifth temperature and then kept warm for a fifth time. The fifth temperature is 340~360℃ and the fifth holding time is 30~60min.

10. The application of the inorganic fiber liner composite material according to any one of claims 1 to 6 or the inorganic fiber liner composite material prepared by the preparation method according to any one of claims 7 to 9 in the actuating parts of aerospace equipment.

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