Polyimide-based fiber composite material and preparation method thereof

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to a polyimide-based fiber composite material and a preparation method thereof. Polyimide thermosetting resin with the structure shown in the formula I is adopted as a resin base material, meanwhile, the mass ratio relation of the resin base material and a reinforcing material in the composite material is controlled, and temperature and pressure control operation of hot pressing operation is strictly controlled when hot pressing is conducted on prepreg, so that polymerization and cross-linking reactions of resin molecules can be more sufficient, and the tensile strength of the prepreg is improved. And the distribution between the resin base material and the reinforcing material is more uniform, so that the formation of non-uniform resin structures, even pores and interlayer virtual connection among reinforcing fibers in the composite material is avoided, and the composite material has excellent anti-impact toughness on the basis of having excellent anti-impact toughness. Meanwhile, the composite material has the characteristics of low porosity, high glass transition temperature, high tensile strength and high bending strength.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and particularly relates to a polyimide-based fiber composite material and a preparation method thereof. Background Art

[0002] In 1972, NASA Lewis Research Center in the United States first reported the preparation of PMR-15 thermosetting polyimide resin by in-situ polymerization of monomer reactants (Thermal Stable Polyimide from Solutions of Monomeric Reactants, J. Appl. Polym. Sci., 1972, 16:905; US Patent 3,745,149), which overcame the poor solubility problem of traditional polyimide resins and had epoch-making significance in the field of polyimide base resins. Its glass transition temperature (Tg) was as high as 316°C, making it the first high-temperature thermosetting polyimide (TSPI) base resin widely used in various high-tech fields such as aviation, aerospace, automobile manufacturing, and oil extraction.

[0003] In the following thirty years, major research centers in the United States successively launched LaRC-RP46 TSPI resin (Lowcost non-MDA polyimide for high temperature applications, SAMPE international symposium, 40 (1), p227), DMBZ-15 TSPI resin (A high Tg PMR polyimide composites DMBZ-15, Journal of advanced materials. 2001, 33 (4): 33), etc., and the glass transition temperature increased with each generation, exceeding 400 ° C. However, due to the high crosslinking density of TSPI resin, the prepared composite laminate has the advantages of high strength, high modulus, high temperature resistance and dimensional stability, but it also leads to increased brittleness of the material. When subjected to impact, it is difficult to absorb and disperse the impact energy, and cracks are formed and quickly collapsed, causing huge economic losses to the aviation, aerospace, automobile manufacturing and mining industries. Summary of the invention

[0004] The object of the present invention is to provide a polyimide-based fiber composite material and a method for preparing the same. The polyimide-based fiber composite material provided by the present invention has excellent impact toughness, and the product has low porosity, high glass transition temperature, high tensile strength and high flexural strength.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a polyimide-based fiber composite material, wherein the polyimide-based fiber composite material comprises the following components in percentage by mass:

[0007] Resin matrix 35-50%, reinforcement material 50-65%;

[0008] The resin substrate is a polyimide thermosetting resin, and the polyimide thermosetting resin has a structure shown in Formula I:

[0009]

[0010] In Formula I: Ar 1 is the residue of an aromatic diamine monomer, Ar 1 One or more selected from phenyl, biphenyl, substituted biphenyl, diphenyl ether and triphenyl ether, wherein the substituent of the substituted biphenyl is C1-10 alkyl or halogen-substituted C1-10 alkyl;

[0011] Ar 2 is the residue of an aromatic dianhydride monomer, Ar 2 One or more selected from phenyl, diphenyl, diphenyl ether and benzophenone;

[0012] Ar 3 is the residue of a long-chain diamine monomer, Ar 3 The number of carbon atoms in the molecule is 5 to 10;

[0013] n is a positive integer from 1 to 5, and m is a positive integer from 1 to 3;

[0014] The reinforcing material comprises fibers and / or fiber fabrics;

[0015] The following steps are involved:

[0016] A monomer mixed solution of polyimide thermosetting resin is used as the resin impregnation liquid;

[0017] The reinforcing material is impregnated with a resin impregnation liquid to obtain an impregnated reinforcing material,

[0018] The impregnated reinforcement material is coated and then rolled up to obtain a prepreg;

[0019] The prepregs are stacked and then hot-pressed to obtain the polyimide-based fiber composite material with high impact toughness;

[0020] The temperature and pressure control program of the hot pressing comprises the following steps: under the first pressure condition, heating from room temperature to the first temperature at a first heating rate for the first insulation, after the first insulation is completed, heating from the first temperature to the second temperature at a second heating rate for the second insulation, after the second insulation is completed, heating from the second temperature to the third temperature at a third heating rate, under the third temperature condition, heating from the first pressure to the second pressure, the first pressure is 0-0.02MPa, the first heating rate is 0.5-3℃ / min, the first temperature is 60-150℃, and the first insulation time is 30-120min; the second heating rate is 0.5-3℃ / min, the second temperature is 120-200℃, the second insulation time is 30-120min, the third heating rate is 0.5-3℃ / min, the third temperature is 150-240℃, and the second pressure is 0.4-1.3MPa;

[0021] Under the second pressure condition, the temperature is increased from the third temperature to the fourth temperature according to the fourth heating rate for the fourth insulation, after the fourth insulation is completed, the temperature is decreased from the fourth temperature to the fifth temperature according to the first cooling rate, and under the fifth temperature condition, the pressure is decreased from the second pressure to the third pressure, the fourth heating rate is 0.5-3°C / min, the fourth temperature is 270-320°C, the fourth insulation time is 30-120min, the first cooling rate is 0.5-3°C / min, the fifth temperature is 60-150°C, and the third pressure is 0-1MPa;

[0022] Under the third pressure condition, the temperature is lowered from the fifth temperature to room temperature at a second cooling rate, wherein the second cooling rate is 0.5-3°C / min.

[0023] Preferably, the solid content of the resin impregnation solution is 50-80%.

[0024] Preferably, the dipping is carried out in a dipping tank, and the dipping temperature is 20-50°C.

[0025] Preferably, the temperature of the coating is 20 to 50° C., and the stretching speed is 5 to 10 cm / s.

[0026] Preferably, Ar 1 Any one or more selected from the structures represented by the following formulas (1) to (7):

[0027]

[0028] Preferably, Ar 2 Any one or more selected from the structures represented by the following formulas (8) to (14):

[0029]

[0030] Preferably, the long alkane chain diamine monomer is selected from one or more of 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane and 1,10-diaminodecane.

[0031] Preferably, the glass transition temperature of the polyimide thermosetting resin is 300-420°C, and the impact toughness is 6.82-8.34 kJ / m 2 .

[0032] Preferably, the reinforcing material comprises one or more of carbon fiber, carbon fiber fabric, glass fiber, glass fabric, organic fiber and organic fiber fabric.

[0033] The present invention provides a polyimide-based fiber composite material prepared by the preparation method described in the above technical solution.

[0034] The present invention provides a method for preparing a polyimide-based fiber composite material. The preparation method provided by the present invention adopts a polyimide thermosetting resin of a structure shown in formula I as a resin substrate, and controls the mass ratio of the resin substrate and the reinforcing material in the composite material: 35-50% of the resin substrate and 50-65% of the reinforcing material. The resin substrate used in the present invention can effectively improve the impact toughness of the composite material by introducing a long alkane chain diamine monomer into the traditional TSPI main molecular chain. At the same time, the present invention can make the polymerization and cross-linking reaction of the resin molecules more sufficient, and the distribution between the resin substrate and the reinforcing material is more uniform, thereby avoiding the formation of non-uniform resin structure or even pores and interlayer virtual connection between the reinforcing fibers in the composite material, resulting in the inability of the reinforcing fibers to fully realize their reinforcing function, thereby adversely affecting the glass transition temperature and mechanical properties of the composite material. In summary, the preparation method provided by the present invention can make the composite material have the characteristics of low porosity, high glass transition temperature, high tensile strength and high flexural strength on the basis of excellent impact toughness.

[0035] The present invention provides a polyimide-based fiber composite material prepared by the preparation method described in the above technical solution. The polyimide-based fiber composite material provided by the present invention has excellent impact toughness, and the product has low porosity, high glass transition temperature, high tensile strength and high bending strength. Moreover, the preparation method provided by the present invention is simple and easy to implement, and is suitable for industrial production. DETAILED DESCRIPTION

[0036] The present invention provides a method for preparing a polyimide-based fiber composite material, wherein the polyimide-based fiber composite material comprises the following components in percentage by mass:

[0037] Resin matrix 35-50%, reinforcement material 50-65%;

[0038] The resin substrate is a polyimide thermosetting resin, and the polyimide thermosetting resin has a structure shown in Formula I:

[0039]

[0040] In Formula I: Ar 1 is the residue of an aromatic diamine monomer, Ar 1 One or more selected from phenyl, biphenyl, substituted biphenyl, diphenyl ether and triphenyl ether, wherein the substituent of the substituted biphenyl is C1-10 alkyl or halogen-substituted C1-10 alkyl;

[0041] Ar 2 is the residue of an aromatic dianhydride monomer, Ar 2 One or more selected from phenyl, diphenyl, diphenyl ether and benzophenone;

[0042] Ar 3 is the residue of a long-chain diamine monomer, Ar 3 The number of carbon atoms in the molecule is 5 to 10;

[0043] n is a positive integer from 1 to 5, and m is a positive integer from 1 to 3;

[0044] The reinforcing material comprises fibers and / or fiber fabrics;

[0045] The following steps are involved:

[0046] A monomer mixed solution of polyimide thermosetting resin is used as the resin impregnation liquid;

[0047] The reinforcing material is impregnated with a resin impregnation liquid to obtain an impregnated reinforcing material,

[0048] The impregnated reinforcement material is coated and then rolled up to obtain a prepreg;

[0049] The prepregs are stacked and then hot-pressed to obtain the polyimide-based fiber composite material with high impact toughness;

[0050] The temperature and pressure control program of the hot pressing comprises the following steps: under the first pressure condition, heating from room temperature to the first temperature at a first heating rate for the first insulation, after the first insulation is completed, heating from the first temperature to the second temperature at a second heating rate for the second insulation, after the second insulation is completed, heating from the second temperature to the third temperature at a third heating rate, under the third temperature condition, heating from the first pressure to the second pressure, the first pressure is 0-0.02MPa, the first heating rate is 0.5-3℃ / min, the first temperature is 60-150℃, and the first insulation time is 30-120min; the second heating rate is 0.5-3℃ / min, the second temperature is 120-200℃, the second insulation time is 30-120min, the third heating rate is 0.5-3℃ / min, the third temperature is 150-240℃, and the second pressure is 0.4-1.3MPa;

[0051] Under the second pressure condition, the temperature is increased from the third temperature to the fourth temperature according to the fourth heating rate for the fourth insulation. After the fourth insulation is completed, the temperature is reduced from the fourth temperature to the fifth temperature according to the first cooling rate. Under the fifth temperature condition, the pressure is reduced from the second pressure to the third pressure, the fourth heating rate is 0.5-3°C / min, the fourth temperature is 270-320°C, the fourth insulation time is 30-120min, the first cooling rate is 0.5-3°C / min, the fifth temperature is 60-150°C, and the third pressure is 0.1-0.4MPa.

[0052] Under the third pressure condition, the temperature is lowered from the fifth temperature to room temperature at a second cooling rate, wherein the second cooling rate is 0.5-3°C / min.

[0053] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well known to those skilled in the art.

[0054] The pressure data appearing in the present invention are all relative pressure data, that is, in the present invention, 0 MPa represents 1 atmosphere.

[0055] The polyimide-based fiber composite material provided by the present invention comprises 35-50% of the resin matrix, and specifically 41.2%, 38.8%, 40%, 45.5% or 48.3% in the embodiments. In the present invention, the resin matrix is ​​a polyimide thermosetting resin, and the polyimide thermosetting resin has a structure shown in Formula I.

[0056] The m toughened and modified polyimide thermosetting resin of the structure shown in Formula I provided by the present invention Unit and n The arrangement order of the units is free to combine, and the structure shown in formula 1 only indicates Unit and The number of units and the connection relationship with the end-capping group.

[0057] In the present invention, the substituent of the substituted biphenyl group is a C1-10 alkyl group or a halogen-substituted C1-10 alkyl group. The C1-10 alkyl group is preferably a C1-5 alkyl group, and is particularly preferably a methyl group, an ethyl group, a propyl group or a butyl group. The halogen-substituted C1-10 alkyl group is preferably a halogen-substituted C1-5 alkyl group, and is particularly preferably a halogen-substituted methyl group, a halogen-substituted ethyl group, a halogen-substituted propyl group or a halogen-substituted butyl group. The halogen is preferably F, Cl or Br.

[0058] In the present invention, Ar 1 Preferably, it is selected from any one or more of the structures represented by the following formulas (1) to (7):

[0059]

[0060] In the present invention, Ar 2 Preferably, it is selected from any one or more of the structures represented by the following formulas (8) to (14):

[0061]

[0062] In the present invention, the long alkane chain diamine monomer is preferably selected from one or more of 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane and 1,10-diaminodecane.

[0063] In the present invention, the glass transition temperature of the polyimide thermosetting resin is preferably 300 to 420°C, and the impact toughness is preferably 6.82 to 8.34 kJ / m 2 .

[0064] The polyimide-based fiber composite material provided by the present invention comprises 50-65% of reinforcing material in terms of mass percentage. In the present invention, the reinforcing material comprises fiber and / or fiber fabric, preferably one or more of carbon fiber, carbon fiber fabric, glass fiber, glass fabric, organic fiber and organic fiber fabric.

[0065] In the present invention, the method for preparing the polyimide-based fiber composite material comprises the following steps:

[0066] The invention adopts a monomer mixed solution of polyimide thermosetting resin as the resin impregnation liquid.

[0067] In the present invention, the method for preparing the monomer mixed solution of the polyimide thermosetting resin comprises the following steps:

[0068] The aromatic dianhydride monomer, the reactive end-capping agent and the alcohol solvent are mixed to carry out an esterification reaction to obtain an esterification solution;

[0069] The esterification solution, aromatic diamine monomer, long alkane diamine monomer and alcohol solvent are mixed to obtain the monomer mixed solution of the polyimide thermosetting resin.

[0070] The present invention mixes an aromatic dianhydride monomer, a reactive end-capping agent and an alcohol solvent (hereinafter referred to as the first alcohol solvent) for esterification reaction to obtain an esterification solution. In the present invention, the aromatic dianhydride monomer preferably includes 3,3,4,4-benzophenone tetracarboxylic dianhydride (BTDA), 4,4-diphenyl ether tetracarboxylic dianhydride (ODPA) or bisphenol A dianhydride (BPADA). The reactive end-capping agent is preferably nadic anhydride (NA). The mass ratio of the aromatic dianhydride monomer and the reactive end-capping agent is preferably 100: (20-55), and in the embodiment, it is specifically 100: 40, 100: 48, 100: 30, 100: 52 or 100: 42. The first alcohol solvent is preferably methanol and / or ethanol, and in the embodiment, it is specifically ethanol. The first alcohol solvent is an anhydrous alcohol solvent. In the present invention, the mixing of the aromatic dianhydride monomer, the reactive end-capping agent and the alcohol solvent preferably includes: adding the aromatic dianhydride monomer and the reactive end-capping agent to the first alcohol solvent. The esterification reaction is preferably carried out under heating reflux, and the temperature of the esterification reaction is preferably 60 to 100° C., more preferably 70 to 80° C. The time of the esterification reaction is preferably 2 to 6 hours, more preferably 3 to 4 hours. The time of the esterification reaction cannot be too long, otherwise it will lead to excessive esterification of the aromatic dianhydride monomer, affecting the further processing of the subsequent prepreg.

[0071] After obtaining the esterification solution, the present invention mixes the esterification solution, aromatic diamine monomer, long alkane diamine monomer and alcohol solvent (hereinafter referred to as the second alcohol solvent) to obtain a monomer mixture solution of the polyimide thermosetting resin. In the present invention, the aromatic diamine monomer is preferably 4,4'-diamino-2,2'-dimethyl-1,1'-biphenyl (m-TOL) or 3,4'-diaminodiphenyl ether (3,4'-ODA). The number of carbon atoms in the long alkane chain diamine monomer is preferably 5 to 10, and the long alkane chain diamine monomer is preferably selected from one or more of 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, and 1,10-diaminodecane; more preferably selected from one or more of 1,7-diaminoheptane (Z7Z), 1,8-diaminooctane (Z8Z), 1,9-diaminononane (Z9Z) and 1,10-diaminodecane (Z10Z). The mass ratio of the aromatic dianhydride monomer to the aromatic diamine monomer is preferably 100:(80 to 130), more preferably 100:(100 to 120), and specifically 100:98, 100:86, 100:90, 100:82 or 100:80 in the embodiments. The mass ratio of the aromatic dianhydride monomer to the long alkane diamine monomer is preferably 100:(5-10), and in the embodiment, it is specifically 100:8, 100:7, 100:9 or 100:10. The second alcohol solvent is preferably methanol and / or ethanol, and in the embodiment, it is specifically ethanol. The second alcohol solvent is an anhydrous alcohol solvent. In the present invention, the mixing of the esterification solution, the aromatic diamine monomer, the long alkane diamine monomer and the second alcohol solvent preferably includes: adding the aromatic diamine monomer and the long alkane diamine monomer to the esterification solution, then adding the second alcohol solvent, and finally stirring and mixing in a protective gas atmosphere. The present invention has no special requirements for the amount of the second alcohol solvent, and ensures that the solid content of the mixture solution obtained after adding the second alcohol solvent is preferably 50-80%. In the present invention, the stirring and mixing is preferably carried out in a protective gas atmosphere, and the protective gas is preferably nitrogen. The temperature of the stirring and mixing is preferably 25-30°C, and the time is preferably 5-15h.

[0072] In the present invention, the solid content of the monomer mixture solution of the polyimide thermosetting resin is preferably 50 to 80%.

[0073] In the present invention, the solid content of the resin impregnation solution is preferably 50-80%. When the solid content of the monomer mixed solution of the polyimide thermosetting resin does not meet the requirements, the present invention preferably uses an alcohol solvent to modulate the monomer mixed solution of the polyimide thermosetting resin to obtain a resin impregnation solution, ensuring that the solid content of the resin impregnation solution is preferably 50-80%, specifically 50% or 55% in the embodiment. The alcohol solvent used for the modulation is preferably ethanol, which is volatile and avoids the toxicity of organic solvents such as methanol.

[0074] After obtaining the resin impregnation liquid, the present invention uses the resin impregnation liquid to dip the reinforcing material to obtain the dipped reinforcing material. In the present invention, the dipping is preferably carried out in a dipping tank, and the dipping temperature is 20-50°C, specifically 30°C, 25°C or 35°C in the embodiment.

[0075] After obtaining the impregnated reinforced material, the present invention coats the impregnated reinforced material and then rolls it up to obtain a prepreg. In the present invention, the coating is preferably a protective film coated on the surface of the impregnated reinforced material. In the present invention, the coating conditions preferably include: the coating temperature is preferably 20 to 50°C, specifically 30°C, 25°C, 40°C or 50°C in the embodiment, and the stretching speed is preferably 5 to 10 cm / s, specifically 5m / s, 6m / s, 9m / s, 8.5m / s or 8m / s in the embodiment. The present invention has no special requirements for the specific implementation method of the rolling.

[0076] After obtaining the prepreg, the present invention stacks the prepreg and then performs hot pressing to obtain the polyimide-based fiber composite material with high impact toughness. In the present invention, before the hot pressing, the present invention preferably peels off the protective film of the prepreg, and then cuts, stacks and applies a release film in sequence.

[0077] The present invention has no special requirements for the specific implementation of the stacking. After the stacking is completed, the present invention preferably attaches a release film to the stacked product and then performs hot pressing. The hot pressing is preferably performed in a hot press. The temperature control procedure of the hot pressing preferably includes: under the first pressure condition, heating from room temperature to a first temperature at a first heating rate for a first insulation, after the first insulation is completed, heating from the first temperature to a second temperature at a second heating rate for a second insulation, after the second insulation is completed, heating from the second temperature to a third temperature at a third heating rate, under the third temperature condition, increasing from the first pressure to the second pressure, the first pressure is preferably 0-0.02MPa, the first heating rate is preferably 0.5-3℃ / min, more preferably 1-3℃ / min, most preferably 2-3℃ / min, the first temperature is preferably 60-150℃, more preferably 150℃, most preferably 250℃. Preferably it is 80-150°C, most preferably 100-150°C, the first insulation time is preferably 30-120min, more preferably 30-60min, most preferably 60min; the second heating rate is preferably 0.5-3°C / min, preferably 0.5-2°C / min, most preferably 0.5-1°C / min, the second temperature is preferably 120-200°C, more preferably 150-200°C, the second insulation time is preferably 30-120min, more preferably 60-120min, most preferably 120min, the third heating rate is 0.5-3°C / min, The temperature of the first embodiment is preferably 1-3 °C / min, more preferably 2-3 °C / min; the third temperature is preferably 150-240 °C, more preferably 200-240 °C, and most preferably 230-240 °C; the second pressure is preferably 0.4-1.3 MPa, more preferably 1-1.3 MPa; under the second pressure condition, the temperature is increased from the third temperature to the fourth temperature at a fourth heating rate for a fourth insulation, and after the fourth insulation is completed, the temperature is decreased from the fourth temperature to the fifth temperature at a first cooling rate, and under the fifth temperature condition, the pressure is decreased from the second pressure to the third pressure, and the fourth heating rate is preferably 0.5-3 °C / min, more preferably 1-3 ℃ / min, most preferably 2℃ / min, the fourth temperature is preferably 270-320℃, more preferably 300-320℃, the fourth insulation time is preferably 30-120min, more preferably 60-120min, most preferably 120min, the first cooling rate is preferably 0.5-3℃ / min, more preferably 1-2℃ / min, the fifth temperature is preferably 60-150℃, more preferably 60-100℃, most preferably 60-80℃, the third pressure is 0-1MPa, preferably 0.1-0.4MPa, specifically 0.4MPa or 0.2MPa in the embodiment.Under the third pressure condition, the temperature is lowered from the fifth temperature to room temperature at a second cooling rate, wherein the second cooling rate is preferably 0.5-3°C / min, more preferably 1-3°C / min, and further preferably 1-2°C / min.

[0078] In the present invention, the operating parameters in the preparation process of the polyimide-based fiber composite material: including the mass ratio of the resin substrate and the reinforcing material, the solid content of the resin impregnation solution, the dipping temperature, the coating temperature, the stretching speed, and especially the temperature and pressure control procedures of the hot pressing (curing temperature, pressure, curing time, heating rate, etc.), slight changes will affect the performance of the final polyimide-based fiber composite material. Among them, too much or too little resin will cause a decrease in the mechanical properties of the composite material. And slight changes in the hot pressing process parameters of the composite material will affect the polymerization and cross-linking reaction of the resin molecules, thereby causing the formation of non-uniform resin structure between fibers and even pores and virtual connections between layers, resulting in the inability of the reinforcing fiber to fully realize its reinforcing function, thereby adversely affecting the glass transition temperature and mechanical properties of the composite material. The preparation method provided by the present invention strictly controls the preparation ratio of the resin substrate and the reinforcing material and the operating parameters of the hot pressing, and adopts a segmented hot pressing method to fully discharge the solvent of the prepreg and the small molecule alcohol and water produced by the imidization reaction from the polyimide-based fiber composite material, and fully cross-link the molecules, thereby effectively ensuring the low porosity, high glass transition temperature, and high tensile and flexural strength of the polyimide-based fiber composite material. In summary, the polyimide-based fiber composite material prepared by the present invention has excellent impact toughness, and the product has low porosity, high glass transition temperature, high tensile strength and high flexural strength.

[0079] The present invention provides a polyimide-based fiber composite material prepared by the preparation method described in the above technical solution.

[0080] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0081] Example 1

[0082] A method for preparing a monomer mixture solution of a polyimide thermosetting resin comprises: adding 100 parts of 3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA) and 48 parts of nadic anhydride (NA) into a three-necked flask containing 118 parts of ethanol, adding a stirring blade, a condenser, a nitrogen branch pipe, and a thermometer, and performing an esterification reaction at 80°C for 4 hours to obtain an ethanol solution of BTDE and NE; adding 7 parts of 1,10-diaminodecane (Z10Z) and 98 parts of 4,4′-diamino-2,2′-dimethyl-1,1′-biphenyl (m-TOL) into the ethanol solution of BTDE and NA, and adding ethanol solution until the solid content is 50%. Stirring is continued for 15 hours under nitrogen protection at room temperature to fully dissolve m-TOL and Z10Z, and then collecting to obtain a monomer mixture solution BNT50-Z107 of a polyimide thermosetting resin toughened and modified by Z10Z.

[0083] Then, a composite laminate was prepared using a monomer mixture solution BNT50-Z107 of a polyimide thermosetting resin toughened and modified by Z10Z and T-300 carbon fiber plain weave cloth:

[0084] a) Prepare carbon fiber cloth of suitable width;

[0085] b) Mix the BNT50-Z107 resin liquid with ethanol to a solid content of 50%, and pour it into a dipping tank, setting the temperature of the dipping tank to 30°C;

[0086] c) Setting the coating temperature to 50°C and the stretching speed to 8 cm / s, and applying the release film;

[0087] d) When the prepreg material at the winding end of the equipment is of good quality and has been evenly impregnated with glue, start winding;

[0088] e) After removing the release film from the prepreg, cutting, stacking, and applying the release film, the prepreg is placed in a hot press to prepare a composite laminate according to the following hot pressing process:

[0089] f) In the first stage, the temperature is raised to 140°C at a pressure of 0.02 MPa, at a rate of 2°C / min, and kept at this temperature for 60 minutes;

[0090] g) In the second stage, the temperature is raised to 190°C at a rate of 1°C / min and kept at this temperature for 120 minutes;

[0091] h) In the third stage, after the temperature is raised to 240°C, the heating rate is 3°C / min and the pressure is increased to 1.2MPa;

[0092] i) In the fourth stage, the temperature is continued to rise to 320°C at a rate of 3°C / min and kept at this temperature for 120 minutes;

[0093] j) In the fifth stage, the temperature is lowered to 60°C, the cooling rate is 2°C / min, and the pressure is reduced to 0.4MPa;

[0094] k) In the sixth stage, the temperature is lowered to room temperature at a rate of 3°C / min, and finally the pressure is released to normal pressure.

[0095] l) Take out the sample, tear off the release film, and cut as needed.

[0096] The obtained polyimide-based fiber composite laminate, in the polyimide-based fiber composite laminate prepared in this embodiment, the mass ratio of polyimide thermosetting resin and T-300 carbon fiber plain cloth is 2.1:3 (that is, the mass percentage of the resin matrix is ​​41.2%, and the mass percentage of the T-300 carbon fiber plain cloth is 58.8%).

[0097] The polyimide-based fiber composite laminate prepared in this embodiment has a glass transition temperature of 418°C and an impact strength of 18.6 kJm 2 .

[0098] Example 2

[0099] A method for preparing a monomer mixture solution of a polyimide thermosetting resin comprises: adding 100 parts of 3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA) and 30 parts of norbornene anhydride (NA) into a three-necked flask containing 105 parts of ethanol, adding a stirring paddle, a condenser, a nitrogen branch pipe, and a thermometer, and performing an esterification reaction at 80°C for 4 hours to obtain an ethanol solution of BTDE and NE; adding 9 parts of 1,8-diaminooctane (Z8Z) and 86 parts of 3,4′-diaminodiphenyl ether (3,4′-ODA) into the ethanol solution of BTDE and NA, and adding ethanol solution until the solid content is 50%. Stirring is continued for 15 hours at room temperature and under nitrogen protection, and after 3,4′-ODA and Z8Z are fully dissolved, the monomer mixture solution BNO50-Z89 of a polyimide thermosetting resin toughened and modified by Z8Z is obtained.

[0100] Then, a composite laminate was prepared using a monomer mixture solution BNO50-Z89 of a Z8Z toughened and modified polyimide thermosetting resin and T-300 carbon fiber plain weave cloth:

[0101] a) Prepare carbon fiber cloth of suitable width;

[0102] b) Mix the BNO50-Z89 resin solution with ethanol to a solid content of 50%, and pour it into a dipping tank, setting the temperature of the dipping tank to 30°C;

[0103] c) setting the coating temperature to 50°C and the stretching speed to 8.5 cm / s, and applying the release film;

[0104] d) When the prepreg material at the winding end of the equipment is of good quality and has been evenly impregnated with glue, start winding;

[0105] e) After removing the release film from the prepreg, cutting, stacking, and applying the release film, the prepreg is placed in a hot press to prepare a composite laminate according to the following hot pressing process:

[0106] f) In the first stage, the temperature is raised to 150°C at a pressure of 0.02 MPa, at a rate of 2°C / min, and kept at this temperature for 60 minutes;

[0107] g) In the second stage, the temperature is raised to 200°C at a rate of 1°C / min and kept at this temperature for 120 minutes;

[0108] h) In the third stage, after the temperature is raised to 240°C, the heating rate is 3°C / min and the pressure is increased to 1.3MPa;

[0109] i) In the fourth stage, the temperature is continued to rise to 310°C at a rate of 3°C / min and kept at this temperature for 120 minutes;

[0110] j) In the fifth stage, the temperature is lowered to 60°C, the cooling rate is 2°C / min, and the pressure is reduced to 0.2MPa;

[0111] k) In the sixth stage, the temperature is lowered to room temperature at a rate of 3°C / min, and finally the pressure is released to normal pressure.

[0112] l) Take out the sample, tear off the release film, and cut as needed.

[0113] The obtained polyimide-based fiber composite laminate, in the polyimide-based fiber composite laminate prepared in this embodiment, the mass ratio of polyimide thermosetting resin and T-300 carbon fiber plain cloth is 1.9:3 (that is, the mass percentage of polyimide thermosetting resin is 38.8%, and the mass percentage of T-300 carbon fiber plain cloth is 61.2%).

[0114] The polyimide-based fiber composite laminate prepared in this embodiment has a glass transition temperature of 390°C and an impact strength of 19.2 kJm 2 .

[0115] Example 3

[0116] A method for preparing a monomer mixture solution of a toughened and modified polyimide thermosetting resin is provided: 100 parts of 4,4-diphenyl ether tetracarboxylic dianhydride (ODPA) and 52 parts of nadic anhydride (NA) are added to a three-necked flask containing 120 parts of ethanol, a stirring blade, a condenser, a nitrogen branch pipe, and a thermometer are added, and an ethanol solution of ODPE and NE is obtained by esterification reaction at 80°C for 4 hours; 10 parts of 1,9-diaminononane (Z9Z) and 90 parts of 3,4′-diaminodiphenyl ether (3,4′-ODA) are added to the ethanol solution of ODPE and NA, and the ethanol solution is supplemented until the solid content is 45%. Stirring is continued for 15 hours at room temperature and under nitrogen protection, 3,4′-ODA and Z9Z are fully dissolved, and then the monomer mixture solution ONO45-Z910 of the Z9Z toughened and modified polyimide thermosetting resin is obtained.

[0117] Then, a composite laminate was prepared using a monomer mixture solution of Z9Z toughened and modified polyimide thermosetting resin ONO45-Z910 and T-300 carbon fiber plain cloth:

[0118] a) Prepare carbon fiber cloth of suitable width;

[0119] b) The ONO45-Z910 resin solution was prepared with ethanol to a solid content of 50%, and poured into a dipping tank, and the temperature of the dipping tank was set to 35°C;

[0120] c) Setting the coating temperature to 40°C and the stretching speed to 9 cm / s, and applying the release film;

[0121] d) When the prepreg material at the winding end of the equipment is of good quality and has been evenly impregnated with glue, start winding;

[0122] e) After removing the release film from the prepreg, cutting, stacking, and applying the release film, the prepreg is placed in a hot press to prepare a composite laminate according to the following hot pressing process:

[0123] f) In the first stage, the temperature was raised to 120°C at a pressure of 0.02 MPa, at a rate of 3°C / min, and kept at this temperature for 60 minutes;

[0124] g) In the second stage, the temperature is raised to 190°C at a rate of 0.5°C / min and kept at this temperature for 120 minutes;

[0125] h) In the third stage, after the temperature is raised to 240°C, the heating rate is 2°C / min and the pressure is increased to 1.0MPa;

[0126] i) In the fourth stage, the temperature is continued to rise to 320°C at a rate of 3°C / min and kept at this temperature for 120 minutes;

[0127] j) In the fifth stage, the temperature is lowered to 80°C, the cooling rate is 2°C / min, and the pressure is reduced to 0.2MPa;

[0128] k) In the sixth stage, the temperature is lowered to room temperature at a rate of 3°C / min, and finally the pressure is released to normal pressure.

[0129] l) Take out the sample, tear off the release film, and cut as needed.

[0130] The obtained polyimide-based fiber composite laminate, in the polyimide-based fiber composite laminate prepared in this embodiment, the mass ratio of polyimide thermosetting resin and T-300 carbon fiber plain cloth is 2:3 (that is, the mass percentage of polyimide thermosetting resin is 40%, and the mass percentage of T-300 carbon fiber plain cloth is 60%).

[0131] The polyimide-based fiber composite laminate prepared in this embodiment has a glass transition temperature of 362°C and an impact strength of 19.8 kJm 2 .

[0132] Example 4

[0133] A method for preparing a monomer mixture solution of a toughened and modified polyimide thermosetting resin is provided: 100 parts of bisphenol A dianhydride (BPADA) and 42 parts of nadic anhydride (NA) are added to a three-necked flask containing 95 parts of ethanol, a stirring blade, a condenser, a nitrogen branch pipe, and a thermometer are added, and an esterification reaction is carried out at 80°C for 4 hours to obtain an ethanol solution of BPADE and NE; 10 parts of 1,7-diaminoheptane (Z7Z) and 82 parts of 4,4′-diamino-2,2′-dimethyl-1,1′-biphenyl (m-TOL) are added to the ethanol solution of BPADE and NA, and the ethanol solution is supplemented until the solid content is 55%. Stirring is continued for 15 hours at room temperature and under nitrogen protection, 3,4′-ODA and Z7Z are fully dissolved, and then the monomer mixture solution BPNT55-Z710 of a Z7Z toughened and modified polyimide thermosetting resin is obtained.

[0134] Then, a composite laminate was prepared using a monomer mixture solution of Z7Z toughened and modified polyimide thermosetting resin BPNT55-Z710 and T-300 carbon fiber plain cloth:

[0135] a) Prepare carbon fiber cloth of suitable width;

[0136] b) Mix the BPNT55-Z710 resin liquid with ethanol to a solid content of 55%, and pour it into a dipping tank, setting the temperature of the dipping tank to 25°C;

[0137] c) Setting the coating temperature to 25°C and the stretching speed to 6 cm / s, and applying the release film;

[0138] d) When the prepreg material at the winding end of the equipment is of good quality and has been evenly impregnated with glue, start winding;

[0139] e) After removing the release film from the prepreg, cutting, stacking, and applying the release film, the prepreg is placed in a hot press to prepare a composite laminate according to the following hot pressing process:

[0140] f) In the first stage, the temperature is raised to 120°C at a pressure of 0.02 MPa, at a rate of 2°C / min, and kept at this temperature for 60 minutes;

[0141] g) In the second stage, the temperature is raised to 180°C at a rate of 1°C / min and kept at this temperature for 120 minutes;

[0142] h) In the third stage, after the temperature is raised to 240°C, the heating rate is 3°C / min and the pressure is increased to 1.3MPa;

[0143] i) In the fourth stage, the temperature is continued to rise to 320°C at a rate of 3°C / min and kept at this temperature for 120 minutes;

[0144] j) In the fifth stage, the temperature is lowered to 70°C, the cooling rate is 1°C / min, and the pressure is reduced to 0.2MPa;

[0145] k) In the sixth stage, the temperature is lowered to room temperature at a rate of 3°C / min, and finally the pressure is released to normal pressure.

[0146] l) Take out the sample, tear off the release film, and cut as needed.

[0147] The obtained polyimide-based fiber composite laminate, in the polyimide-based fiber composite laminate prepared in this embodiment, the mass ratio of polyimide thermosetting resin and T-300 carbon fiber plain cloth is 2.5:3 (that is, the mass percentage of polyimide thermosetting resin is 45.5%, and the mass percentage of T-300 carbon fiber plain cloth is 54.5%).

[0148] The polyimide-based fiber composite laminate prepared in this embodiment has a glass transition temperature of 333°C and an impact strength of 20.1 kJm 2 .

[0149] Example 5

[0150] A method for preparing a monomer mixture solution of a toughened and modified polyimide thermosetting resin is provided: 100 parts of bisphenol A dianhydride (BPADA) and 42 parts of norbornene anhydride (NA) are added to a three-necked flask containing 95 parts of ethanol, and a stirring blade, a condenser, a nitrogen branch pipe, and a thermometer are added, and an esterification reaction is carried out at 80°C for 4 hours to obtain an ethanol solution of BPADE and NE; 7 parts of 1,10-diaminodecane (Z10Z) and 80 parts of 3,4′-diaminodiphenyl ether (3,4′-ODA) are added to the ethanol solution of BPADE and NA, and the ethanol solution is supplemented until the solid content is 55%. Stirring is continued for 15 hours at room temperature and under nitrogen protection, 3,4′-ODA and Z10Z are fully dissolved, and then the mixture is collected to obtain a monomer mixture solution BPNO55-Z107 of a Z10Z toughened and modified polyimide thermosetting resin.

[0151] Then, a composite laminate was prepared using a monomer mixture solution of Z10Z toughened and modified polyimide thermosetting resin BPNO55-Z107 and T-300 carbon fiber plain cloth:

[0152] a) Prepare carbon fiber cloth of suitable width;

[0153] b) Mix the BPNO55-Z107 resin liquid with ethanol to a solid content of 55%, and pour it into a dipping tank, setting the temperature of the dipping tank to 30°C;

[0154] c) Setting the coating temperature to 30°C and the stretching speed to 5 cm / s, and applying the release film;

[0155] d) When the prepreg material at the winding end of the equipment is of good quality and has been evenly impregnated with glue, start winding;

[0156] e) After removing the release film from the prepreg, cutting, stacking, and applying the release film, the prepreg is placed in a hot press to prepare a composite laminate according to the following hot pressing process:

[0157] f) In the first stage, the temperature is raised to 150°C at a pressure of 0.02 MPa, at a rate of 2°C / min, and kept at this temperature for 60 minutes;

[0158] g) In the second stage, the temperature is raised to 180°C at a rate of 1°C / min and kept at this temperature for 120 minutes;

[0159] h) In the third stage, after the temperature is raised to 230°C, the heating rate is 2°C / min and the pressure is increased to 1.0MPa;

[0160] i) In the fourth stage, the temperature is continued to rise to 320°C at a rate of 3°C / min and kept at this temperature for 120 minutes;

[0161] j) In the fifth stage, the temperature is lowered to 60°C, the cooling rate is 1°C / min, and the pressure is reduced to 0.2MPa;

[0162] k) In the sixth stage, the temperature is lowered to room temperature at a rate of 3°C / min, and finally the pressure is released to normal pressure.

[0163] l) Take out the sample, tear off the release film, and cut as needed.

[0164] The obtained polyimide-based fiber composite laminate, in the polyimide-based fiber composite laminate prepared in this embodiment, the mass ratio of polyimide thermosetting resin and T-300 carbon fiber plain cloth is 2.8:3 (that is, the mass percentage of polyimide thermosetting resin is 48.3%, and the mass percentage of T-300 carbon fiber plain cloth is 51.7%).

[0165] The polyimide-based fiber composite laminate prepared in this embodiment has a glass transition temperature of 315°C and an impact strength of 19.8 kJ m 2 .

[0166] The properties of the composite laminates prepared in Examples 1 to 5 were tested, and the test results are shown in Table 1.

[0167] Table 1 Performance test results of the composite laminates prepared in Examples 1 to 5

[0168]

[0169] From the above examples, it can be seen that the resin substrate used in the present invention can effectively improve the impact toughness of the composite material by introducing a long alkane chain diamine monomer into the traditional TSPI main molecular chain. At the same time, the present invention can make the composite material have the characteristics of low porosity, high glass transition temperature, high tensile strength and high flexural strength on the basis of excellent impact toughness by reasonably setting the mass ratio relationship between the resin substrate and the reinforcing material.

[0170] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a polyimide-based fiber composite material, characterized in that: The polyimide-based fiber composite material comprises the following components in percentage by mass: Resin matrix 35-50%, reinforcement material 50-65%; The resin substrate is a polyimide thermosetting resin, and the polyimide thermosetting resin has a structure shown in Formula I: In formula I: Ar1 is a residue of an aromatic diamine monomer, Ar1 is selected from one or more of a phenyl group, a biphenyl group, a substituted biphenyl group, a diphenyl ether group and a triphenyl ether group, and the substituent of the substituted biphenyl group is a C1-10 alkyl group or a halogen-substituted C1-10 alkyl group; Ar2 is a residue of an aromatic dianhydride monomer, and Ar2 is selected from one or more of a phenyl group, a biphenyl group, a diphenyl ether group, and a benzophenone group; Ar3 is a residue of a long alkane chain diamine monomer, and the number of carbon atoms in Ar3 is 5 to 10; n is a positive integer from 1 to 5, and m is a positive integer from 1 to 3; The reinforcing material comprises fibers and / or fiber fabrics; The following steps are involved: A monomer mixed solution of polyimide thermosetting resin is used as the resin impregnation liquid; The reinforcing material is impregnated with a resin impregnation liquid to obtain an impregnated reinforcing material, The impregnated reinforcement material is coated and then rolled up to obtain a prepreg; The prepregs are stacked and then hot-pressed to obtain the polyimide-based fiber composite material with high impact toughness; The temperature and pressure control program of the hot pressing comprises the following steps: under the first pressure condition, heating from room temperature to the first temperature at a first heating rate for the first insulation, after the first insulation is completed, heating from the first temperature to the second temperature at a second heating rate for the second insulation, after the second insulation is completed, heating from the second temperature to the third temperature at a third heating rate, under the third temperature condition, heating from the first pressure to the second pressure, the first pressure is 0-0.02MPa, the first heating rate is 0.5-3℃ / min, the first temperature is 60-150℃, and the first insulation time is 30-120min; the second heating rate is 0.5-3℃ / min, the second temperature is 120-200℃, the second insulation time is 30-120min, the third heating rate is 0.5-3℃ / min, the third temperature is 150-240℃, and the second pressure is 0.4-1.3MPa; Under the second pressure condition, the temperature is increased from the third temperature to the fourth temperature according to the fourth heating rate for the fourth insulation, after the fourth insulation is completed, the temperature is decreased from the fourth temperature to the fifth temperature according to the first cooling rate, and under the fifth temperature condition, the pressure is decreased from the second pressure to the third pressure, the fourth heating rate is 0.5-3°C / min, the fourth temperature is 270-320°C, the fourth insulation time is 30-120min, the first cooling rate is 0.5-3°C / min, the fifth temperature is 60-150°C, and the third pressure is 0-1MPa; Under the third pressure condition, the temperature is lowered from the fifth temperature to room temperature at a second cooling rate, wherein the second cooling rate is 0.5-3°C / min.

2. The preparation method according to claim 1, characterized in that: The solid content of the resin impregnation solution is 50-80%.

3. The preparation method according to claim 1 or 2, characterized in that: The dipping is carried out in a dipping tank, and the temperature of the dipping is 20-50°C.

4. The preparation method according to claim 1, characterized in that: The temperature of the coating film is 20-50° C., and the stretching speed is 5-10 cm / s.

5. The preparation method according to claim 1, characterized in that: Ar1 is selected from any one or more of the structures represented by the following formula (1) to formula (7):

6. The preparation method according to claim 1, characterized in that: Ar2 is selected from any one or more of the structures shown in the following formula (8) to formula (14):

7. The preparation method according to claim 1, characterized in that: The long alkane chain diamine monomer is selected from one or more of 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane and 1,10-diaminodecane.

8. The preparation method according to claim 1, characterized in that: The polyimide thermosetting resin has a glass transition temperature of 300 to 420° C. and an impact toughness of 6.82 to 8.34 kJ / m 2 .

9. The preparation method according to claim 1, characterized in that: The reinforcing material includes one or more of carbon fiber, carbon fiber fabric, glass fiber, glass fabric, organic fiber and organic fiber fabric.

10. The polyimide-based fiber composite material prepared by the preparation method according to any one of claims 1 to 9.

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