Crystalline polyarylene ether ketone surface grafted carbon nanotube and preparation method thereof

Abstract

The application discloses a crystalline polyarylene ether ketone surface grafted carbon nanotube and a preparation method thereof, and belongs to the technical field of carbon materials, wherein the preparation method comprises the following steps: placing a sulfonyl-containing amino capping agent, a difluoromonomer, a bisphenol monomer and potassium carbonate in a sulfolane to perform a polymerization reaction, so as to obtain an amino-capped polyarylene ether; performing a diazonium salt reaction on the amino-capped polyarylene ether and a nitrite salt of tetrafluoroboric acid, so as to obtain a diazonium salt-capped polyarylene ether; connecting the carbon nanotube to a cathode, immersing the carbon nanotube in an electrolyte containing the diazonium salt-capped polyarylene ether, and applying a reduction potential to perform a reaction, so as to obtain a polyarylene ether grafted carbon nanotube; and performing a hydrolysis reaction on the polyarylene ether grafted carbon nanotube in an acidic environment, so as to obtain the crystalline polyarylene ether ketone surface grafted carbon nanotube. The crystalline polyarylene ether ketone surface grafted and modified carbon nanotube prepared by the application has better high-temperature resistance and corrosion resistance, because the carbon nanotube is directly connected with the polymer through the high-temperature-resistant and corrosion-resistant phenyl and sulfonyl groups.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon materials, in particular to a crystalline polyaryletherketone surface-grafted carbon nanotube and a preparation method thereof. Background Art

[0002] Carbon nanotubes are one-dimensional carbon materials with the characteristics of large aspect ratio, large surface area and good conductivity. They are a kind of functional nano-reinforcement. However, due to the large aspect ratio and high surface energy of carbon nanotubes, they are easy to agglomerate and difficult to disperse. In addition, there is a lack of effective interaction between carbon nanotubes and crystalline polyaryletherketones, so the interface is relatively weak, which brings potential hidden dangers. Therefore, it is necessary to improve the dispersion of carbon nanotubes and the interfacial interaction with polyaryletherketones through chemical bond grafting. There are four problems in grafting crystalline polyaryletherketones onto the surface of carbon nanotubes through chemical bonds:

[0003] (1) In order to ensure that the interface has good compatibility with the resin matrix and the interface phase also has the same corrosion resistance and high temperature resistance as the polyaryletherketone resin matrix, it is necessary to graft crystalline polyaryletherketone onto the surface of carbon nanotubes;

[0004] (2) The excellent corrosion resistance of crystalline polyaryletherketone results in the lack of effective solvents, making it difficult for effective chemical reactions to occur in the solid phase;

[0005] (3) Functional groups such as ester, amide, aliphatic ether and alkyl groups are usually not resistant to high temperatures, and their decomposition temperature is usually less than or equal to 300°C, which cannot meet the molding requirements of crystalline polyaryletherketone at 400°C. Therefore, grafting needs to be achieved through stable and high-temperature resistant chemical bonds;

[0006] (4) Chemical bond grafting needs to be achieved efficiently.

[0007] A large number of carbon nanotube surface modification works based on chemical bond grafting have been carried out at home and abroad, but none of them can solve the above problems at the same time: CN114507356A discloses a method for grafting phenolphthalein-type polyaryletherketone onto the surface of carbon nanotubes via ester groups. The carbonyl groups in the soluble phenolphthalein-type polyaryletherketone (non-crystalline) are reduced to hydroxyl groups in the solution state by using a reducing agent, and then ester groups are formed with the carboxyl groups on the surface of the carbon nanotubes through an esterification reaction. This method not only fails to achieve chemical bond grafting of crystalline polyaryletherketone, but the ester group also does not have high temperature resistance. CN105838086B adopts a similar strategy, conducting a "solid-solid" phase sulfonation reaction between surface hydroxylated polyetheretherketone (insoluble) and surface sulfonated carbon nanotubes under suspension conditions. This not only faces the problem of poor heat resistance of the sulfonate structure, but also cannot overcome the problem of low "solid-solid" phase reaction efficiency. CN112940450B discloses a method for achieving grafting through click chemistry reaction between azide functional groups and carbon nanotube surfaces. Based on methylated polyaryletherketone (non-crystallizable and poorly heat-resistant), sodium azide is used to convert methyl groups into azide functional groups, which are then reacted with carbon nanotubes to achieve grafting. This method not only fails to achieve chemical bond grafting of crystalline polyaryletherketone, but also uses highly toxic and explosive sodium azide, making industrialization difficult. CN116874885A discloses a method for grafting soluble biphenyl-resistant polyarylether by diazotization of carbon nanotubes. This method not only has a long grafting reaction time (5-30h), but also fails to achieve chemical bond grafting of crystalline polyaryletherketone.

[0008] CN109851731B discloses a method for functionalizing the surface of carbon nanotubes and chemically grafting them onto polyetheretherketone (PEEK) via in-situ polymerization. This method involves a concurrent polymerization reaction of the PEEK during the grafting process, resulting in a carbon nanotube-doped PEEK composite material, rather than dispersible modified carbon nanotubes. Summary of the Invention

[0009] The object of the present invention is to provide a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone) to solve the problems raised in the above background technology.

[0010] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0011] A method for preparing carbon nanotubes grafted onto the surface of crystalline polyaryletherketone comprises the following steps:

[0012] The amide-containing sulfonyl halide compound and halogenated benzene are subjected to sulfonation reaction and acid hydrolysis reaction in sequence to obtain an amino-terminated agent containing a sulfone group;

[0013] An amino-terminated agent containing a sulfone group, a difluoro monomer, a bisphenol monomer, and potassium carbonate are placed in sulfolane to carry out a polymerization reaction to obtain an amino-terminated polyarylether;

[0014] The amino-terminated polyarylether is reacted with nitrosotetrafluoroborate to obtain a diazonium salt-terminated polyarylether;

[0015] The diazonium salt-capped polyarylether is prepared into an electrolyte, the carbon nanotubes are connected to a cathode, and immersed in the electrolyte containing the diazonium salt-capped polyarylether, and a reduction potential is applied to react to obtain carbon nanotubes grafted with the polyarylether;

[0016] The carbon nanotubes grafted with polyarylether are subjected to hydrolysis reaction in an acidic environment to obtain crystalline polyaryletherketone surface-grafted carbon nanotubes.

[0017] Preferably, the halogenated benzene is chlorobenzene or fluorobenzene.

[0018] Preferably, the step of sequentially subjecting an amide-containing sulfonyl halide compound and a halogenated benzene to a sulfonation reaction and an acidolysis reaction to obtain an amino-capping agent containing a sulfone group specifically comprises:

[0019] Under the condition of no more than -5°C and inert gas protection, the amide-containing sulfonyl halide compound is fully dissolved in halogenated benzene, and AlCl3 powder is added in batches; then the temperature is raised to room temperature and stirred; the temperature is further raised to reflux; deionized water is added to azeotropic reflux to separate the unreacted halogenated benzene; the crude product is filtered and the filter residue is washed to obtain a crude product; the crude product is recrystallized three times with ethanol and dried to obtain a capping agent precursor;

[0020] The capping agent precursor is dissolved in a mixture of concentrated hydrochloric acid and ethanol and refluxed; then extracted with ethyl acetate, the organic phases are combined and dried over anhydrous sodium sulfate; then filtered and concentrated to obtain an amino capping agent containing a sulfone group.

[0021] Preferably, the difluoro monomer is 4,4'-difluorobenzophenone imine and / or difluorodiketone imine; and the bisphenol monomer is at least one of hydroquinone, biphenol, 4,4'-dihydroxybenzophenone and 4,4'-dihydroxydiphenyl ether.

[0022] Preferably, the step of placing an amino-terminated agent containing a sulfone group, a difluoro monomer, a bisphenol monomer, and potassium carbonate in sulfolane for polymerization to obtain an amino-terminated polyarylene ether specifically comprises:

[0023] An amino-terminated agent containing a sulfone group, a difluoro monomer, a bisphenol monomer, and potassium carbonate are added simultaneously to sulfolane; toluene is then added, the temperature is raised to azeotropic, and after toluene is maintained at reflux for a certain period of time, the toluene is completely discharged; the temperature is continued to be raised to no less than 210°C for reaction; the material is then discharged into ethanol, crushed, washed, and dried to obtain an amino-terminated polyarylene ether.

[0024] Preferably, the step of reacting the amino-terminated polyarylene ether with nitrosotetrafluoroborate to form a diazonium salt to obtain the diazonium salt-terminated polyarylene ether specifically comprises:

[0025] The amino-terminated polyarylether is dissolved in 1,4-dioxane; the above solution is added dropwise into an acetonitrile solution containing nitrite tetrafluoroborate; when the solution becomes a dark brown transparent solution, the material is discharged into ether, and the diazonium-terminated polyarylether is quickly precipitated, which is filtered and washed with ether to obtain the diazonium-terminated polyarylether.

[0026] Preferably, the steps of preparing an electrolyte containing diazonium salt-capped polyarylene ether, connecting carbon nanotubes to a cathode, immersing the carbon nanotubes in the electrolyte containing diazonium salt-capped polyarylene ether, and applying a reducing potential to react to obtain carbon nanotubes grafted with polyarylene ether include:

[0027] The diazonium salt-terminated polyarylether and supporting electrolyte are dissolved in acetonitrile to prepare an electrolyte solution;

[0028] The carbon nanotubes are connected to a cathode, immersed in an electrolyte, and subjected to a reduction potential for reaction. The electrochemically reduced carbon nanotubes are washed with acetonitrile and dried to obtain carbon nanotubes grafted with polyarylene ether.

[0029] Preferably, the supporting electrolyte is tetrabutylammonium tetrafluoroborate.

[0030] Preferably, the step of hydrolyzing the carbon nanotubes grafted with polyarylether in an acidic environment to obtain crystalline polyaryletherketone surface-grafted carbon nanotubes specifically comprises:

[0031] The carbon nanotubes grafted with polyarylether are placed in acetone, mechanically stirred and ultrasonically dispersed; then, hydrochloric acid is added dropwise under the conditions of mechanical stirring and ultrasonic dispersion, and the temperature is raised to reflux; then, the carbon nanotubes grafted with crystalline polyaryletherketone are obtained by filtering, washing and drying.

[0032] Another object of the present invention is to provide a crystalline polyaryletherketone surface-grafted carbon nanotube prepared by the above preparation method.

[0033] The present invention provides a method for preparing crystalline polyaryletherketone surface-grafted carbon nanotubes, wherein an amino-terminated agent containing a sulfone group is prepared, and the amino-terminated agent containing a sulfone group is used to realize a "one-pot method" for preparing amino-terminated polyarylether and diazonium-terminated polyarylether; the surface of the carbon nanotube is modified by using the diazonium-terminated polyarylether, and the carbon nanotube can be directly connected to the polymer via the high-temperature and corrosion-resistant phenyl group and the sulfone group, and the polyaryletherketone grafted on the surface of the carbon nanotube has crystallinity.

[0034] The raw materials used in the present invention are relatively inexpensive, and the prepared amino end-capping agent containing a sulfone group has high reactivity, which can avoid the end-capping polymerization of "polymerization first and then end-capping" and realize "one-pot" end-capping polymerization, thereby reducing the reaction cycle (omitting the 2-6 hours of the post-end-capping process).

[0035] The crystalline poly(aryletherketone) surface-grafted carbon nanotubes produced by the present invention exhibits enhanced heat and corrosion resistance because the carbon nanotubes are directly linked to the polymer via heat-resistant and corrosion-resistant phenyl and sulfone groups, avoiding the use of heat- and corrosion-intolerant functional groups such as ester groups used in conventional mechanisms. Furthermore, the crystalline poly(aryletherketone) is chemically grafted onto the carbon nanotube surface, resulting in even better corrosion resistance.

[0036] The preparation method provided by the present invention avoids traditional reactions such as esterification and amidation, and uses electrochemical reduction as the grafting method. Due to the high reaction efficiency (3-5 min), it can achieve batch preparation of crystalline polyaryletherketone surface-grafted carbon nanotubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the structural formula of the carbon nanotube grafted with polyarylene ether prepared in an embodiment of the present invention;

[0038] Figure 2 is the structural formula of carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone) prepared in an embodiment of the present invention;

[0039] Figure 3 This is a Raman spectrum characterization result of carbon nanotubes grafted on the surface of crystalline poly(aryletherketone) prepared in an embodiment of the present invention;

[0040] Figure 4 The cyclic voltammetry curve of the electrochemical reduction grafting reaction provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] The present invention first prepares an amino-terminated polymer containing a diphenylsulfone structure through a sulfonation reaction using an inexpensive reagent. Leveraging its high reactivity (the higher the electron-withdrawing capacity of the fluorobenzene para-position functional group, the higher the substitution reaction activity, as evidenced by the significantly lower polymerization reactivity of 4,4'-difluorobenzophenone compared to 4,4'-difluorodiphenylmethylsulfone), the amino-terminated polymer is prepared. Furthermore, a diazonium salt functional group is directly constructed at the polymer end group, and the polymer is efficiently grafted onto the carbon nanotube surface through an electrochemical reduction reaction (3-5 minutes). Finally, the polymer grafted onto the carbon fiber surface is converted into a crystalline polyaryletherketone through a hydrolysis reaction. This invention achieves surface grafting of carbon nanotubes using high-temperature-resistant phenylene and sulfone groups.

[0043] The end-capping agent used in the embodiments of the present invention is characterized by a diphenylsulfone structure constructed via a sulfonation reaction, in which the para position of one phenyl group is replaced by a fluorine or chlorine atom, and the para position of the other phenyl group is directly or indirectly linked to an aniline functional group. The para-position of the sulfone group to the fluorine (chlorine) atom significantly improves the reaction efficiency of the end-capping agent, enabling "one-pot" end-capping polymerization. Its synthesis method involves preparing an end-capping agent precursor via a sulfonation reaction using an amide-containing sulfonyl halide compound and a halogenated benzene as raw materials. The end-capping agent is then prepared by converting the amide to an amino group via acid hydrolysis. The specific reaction scheme is as follows:

[0044] ;

[0045] Among them, the structural formula of the amide-containing sulfonyl halide compound is: .

[0046] X is F or Cl; the structural formula of R is:

[0047] ;

[0048] Correspondingly, The structural formula is:

[0049] .

[0050] The amino-terminated polyarylene ether prepared in the examples of the present invention is characterized by being directly prepared via a one-pot polymerization process, with the polymer backbone linked to the aniline end groups via sulfone groups. The one-pot polymerization method involves simultaneously adding a capping agent, a difluoromonomer, a bisphenol monomer, and potassium carbonate to sulfolane (solvent), followed by azeotropic removal of water and subsequent polymerization to obtain the amino-terminated polyarylene ether. The specific reaction scheme is as follows:

[0051] ;

[0052] Wherein, the structural formula of bisphenol monomer is any one of the following:

[0053] ;

[0054] .

[0055] The structural formula of the difluoro monomer is any of the following:

[0056] .

[0057] The structural formula of the amino-terminated polyarylene ether is any one of the following:

[0058]

[0059] ;

[0060] Among them, the structural formula of R in these structural formulas is any one of the following:

[0061] .

[0062] The diazonium salt-terminated polyarylether prepared in the present invention is characterized by a polymer backbone connected to the end groups of phenyl diazonium tetrafluoroborate via a sulfone group. The embodiment is to prepare the diazonium salt-terminated polyarylether by reacting nitrosotetrafluoroborate with a diazonium salt of an aniline end group. The specific reaction scheme is as follows:

[0063]

[0064] Wherein, the structural formula of the diazonium salt-terminated polyarylene ether is any one of the following:

[0065]

[0066] ;

[0067] Wherein, the structural formula of R1 is any of the following:

[0068] .

[0069] The polyarylene ether surface-grafted carbon nanotubes prepared in the embodiments of the present invention are characterized by: through an efficient electrochemical reduction reaction, the surface of the carbon nanotube paper (bucky paper) or carbon nanotube fiber is directly connected to the polyarylene ether via phenyl and sulfone groups. The specific method is: the carbon nanotube paper (bucky paper) or carbon nanotube fiber is connected to the cathode of the electrolytic cell, immersed in an electrolyte (containing diazonium salt-capped polyarylene ether), a reduction potential is applied to react, and after washing and drying, the polyarylene ether-grafted carbon nanotubes are obtained. Its structural formula is as follows: Figure 1 shown. Figure 1 In the present invention, the structural formula of the polyarylene ether is any one of the following:

[0070]

[0071] .

[0072] The poly(aryletherketone) surface-grafted carbon nanotubes prepared in the embodiment of the present invention are characterized in that the surface of the carbon nanotubes is directly connected to the crystalline poly(aryletherketone) via phenyl and sulfone groups. The method is as follows: the carbon nanotubes grafted with poly(arylether) are hydrolyzed in an acidic environment to form crystalline poly(aryletherketone) to obtain crystalline poly(aryletherketone) surface-grafted carbon nanotubes. The structure of the carbon nanotubes is as follows: Figure 2 shown. Figure 2 In the embodiment, the structural formula of the crystalline polyaryletherketone is any one of the following:

[0073]

[0074]

[0075] ;

[0076] in addition, Figure 1 and Figure 2 In the formula of R2, any one of the following is present:

[0077] .

[0078] Specifically, in one embodiment of the present invention, a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone) is provided, which comprises the following steps:

[0079] S1. Under the protection of inert gas at a temperature not exceeding -5°C, fully dissolve the amide-containing sulfonyl halide compound in halogenated benzene (both as a solvent and a reactant), and add AlCl3 powder (1.2-1.5 times the molar amount of the sulfonyl chloride functional group) in batches; then warm to room temperature and stir for 3-5 hours; continue to heat to reflux and stir for 8-10 hours; add deionized water to azeotropically reflux and separate the unreacted halogenated benzene; filter, and wash the filter residue with NaOH solution (0.5-1.5 mol / L) and deionized water in sequence to obtain a crude product; recrystallize the crude product three times with ethanol, and dry it to obtain a capping agent precursor;

[0080] S2. Dissolve the capping agent precursor in a mixture of concentrated hydrochloric acid (0.1-1 mol / L) and ethanol (0.1-1 mol / L) and reflux overnight, then extract with ethyl acetate (80 mL x 3). The combined organic phases are dried over anhydrous sodium sulfate, filtered, and concentrated to obtain the amino capping agent containing a sulfone group.

[0081] S3. Adding a sulfone-containing amino end-capping agent (the molar amount of the end-capping agent is 1%-20% of the molar amount of the bisphenol monomer), a difluoro monomer, a bisphenol monomer, and potassium carbonate simultaneously to sulfolane (solvent); then adding toluene, raising the temperature to azeotropic (130-150° C.), maintaining toluene reflux for 3-5 hours, and then draining the toluene; continuing to raise the temperature to no less than 210° C. to carry out the reaction, and maintaining it for 3-5 hours; then discharging the material into ethanol, crushing it, and washing it with ethanol and water three times each, and drying it to obtain an amino-terminated polyarylene ether;

[0082] S4. Dissolve the amino-terminated polyarylether in 1,4-dioxane (amino end group equivalent 0.01-0.1 mol / L); add the above solution dropwise to an acetonitrile solution (0.01-0.1 mol / L) containing nitrosotetrafluoroborate (NOBF4); when the solution becomes a dark brown transparent solution, discharge the solution into ether to quickly precipitate the diazonium-terminated polyarylether, filter it, and wash it with ether to obtain the diazonium-terminated polyarylether;

[0083] S5. Dissolving diazonium salt-capped poly(arylene ether) (0.01-0.1 g / mL) and supporting electrolyte (0.5-1.5 mM) in acetonitrile to prepare an electrolyte; connecting carbon nanotube paper (buckypaper) or carbon nanotube fiber to a cathode, immersing the carbon nanotube paper in the electrolyte, and applying a reduction potential of -0.3 V for 1-5 minutes. The electrochemically reduced carbon nanotubes are washed with acetonitrile and dried to obtain carbon nanotubes grafted with poly(arylene ether);

[0084] S6. Place the carbon nanotubes grafted with polyarylether in acetone (0.01-0.05 g / mL), mechanically stir and ultrasonically disperse for 1-3 hours; under the conditions of mechanical stirring and ultrasonic dispersion, add 1-3 M hydrochloric acid in an equal volume to the acetone, raise the temperature to reflux, and maintain for 20-28 hours; then filter, wash with deionized water several times, and dry to obtain crystalline polyaryletherketone surface-grafted carbon nanotubes.

[0085] The following embodiments are some specific implementation cases and application cases of the present invention in practical applications, but are not limited thereto.

[0086] Example 1: This example provides a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone), which specifically comprises the following steps:

[0087] (1) At -5 °C and under inert gas protection, 4-acetamidobenzenesulfonyl chloride (0.1 mol) was fully dissolved in chlorobenzene (chlorobenzene was used as both solvent and reactant), and AlCl3 powder (0.12 mol) was added in 5 batches; the mixture was heated to room temperature and stirred for 3 hours; the mixture was heated to reflux and stirred for 8 hours; deionized water was added to azeotropically reflux and separate the unreacted chlorobenzene; the mixture was filtered and the residue (crude product) was washed with NaOH solution (1 mol / L) and deionized water in sequence; the product was recrystallized three times with ethanol and dried to obtain the end-capping agent precursor (N-(4-((4-chlorophenyl)sulfonyl)phenyl)acetamide, corresponding to the above chemical formula: R'=R'-1; X=Cl), with a yield of 85%;

[0088] (2) The capping agent precursor obtained in step (2) was dissolved in a mixture of concentrated hydrochloric acid (0.1 mol / L) and ethanol (0.1 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-chloro-4'-aminodiphenyl sulfone, corresponding to the above chemical formula: R''= R''-1; X= Cl), with a yield of 95%;

[0089] (3) 0.001 mol of the end-capping agent (4-chloro-4'-aminodiphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorobenzophenone imine, 0.1 mol of hydroquinone and 0.13 mol of potassium carbonate were added to sulfolane (solvent) at the same time; toluene was added, the temperature was raised to azeotropic (130°C), toluene and water were kept under azeotropic reflux for 4 hours, and the toluene was exhausted; the temperature was raised to 210°C and kept under azeotropic reflux for 4 hours; the material was discharged into ethanol and crushed; the product was washed with ethanol and water 3 times each, and dried to obtain amino-terminated polyetheretherketone imine (corresponding to the above chemical formula: NH2-PI-1; R=R1-1);

[0090] (4) The amino-terminated polyetheretherketone imine obtained in step (3) is dissolved in 1,4-dioxane (amino end group equivalent 0.01 mol / L); the above solution is added dropwise to an acetonitrile solution (0.01 mol / L) containing 1.5 times the amino end group equivalent of tetrafluoroborate nitrite; when the solution becomes a dark brown transparent solution, the material is discharged into ether, and the diazonium salt-terminated polyarylether is rapidly precipitated, filtered and washed with ether to obtain a diazonium salt-terminated polyetheretherketone imine (corresponding to the above chemical formula: Dia-PI-1; R1=R1-1);

[0091] (5) The diazonium salt end-capped polyether ether ketone imine (0.01 g / mL) obtained in step (4) is dissolved in acetonitrile as an electrolyte with a supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM); the carbon nanotube paper (bucky paper) is connected to the cathode of an electrolytic cell and immersed in the electrolyte; a reduction potential of -0.3 V is applied for 3 min to perform an electrochemical reduction grafting reaction, and a cyclic voltammogram of the electrochemical reduction grafting reaction is as shown in Figure 4 The carbon nanotubes grafted with polyether ether ketone imine (corresponding to the chemical structural formula: PI-1; R2-= R2-1) are obtained by washing the electrochemically reduced carbon nanotubes with acetonitrile and drying.

[0092] (6) The carbon nanotubes grafted with polyether ether ketone imine obtained in step (5) are immersed in acetone (0.01 g / mL) and mechanically stirred and ultrasonically dispersed for 2 hours; under the condition of mechanical stirring and ultrasonic dispersion, 2 M hydrochloric acid is added dropwise in an equal volume of acetone; under the condition of mechanical stirring and ultrasonic dispersion, the temperature is raised to reflux and maintained for 24 h; filtration, washing with deionized water for 3 times, and drying to obtain crystalline polyether ether ketone surface-grafted modified carbon nanotubes (corresponding to the chemical structural formula: P-1; R2-= R2-1). The crystalline polyether ether ketone surface-grafted modified carbon nanotubes prepared above are characterized by Raman spectroscopy, and the results are as shown in Figure 3 The results show that the crystalline polyaryletherketone is successfully grafted on the surface of the carbon nanotubes.

[0093] Example 2: The example provides a preparation method of crystalline polyaryletherketone surface-grafted carbon nanotubes, which specifically includes the following steps:

[0094] (1) Under the condition of -5 ℃ and inert gas protection, 4'-acetamido-[1,1'-biphenyl]-4-sulfonyl chloride (0.1 mol) is fully dissolved in fluorobenzene (fluorobenzene is used as a solvent and also as a reactant), and AlCl3 powder (0.15 mol) is added in 5 batches; the temperature is raised to room temperature, and stirred for 5 hours; the temperature is raised to reflux, and stirred for 10 hours; deionized water is added for azeotropic reflux to separate the unreacted fluorobenzene; the filter residue (crude product) is washed with NaOH solution (1 mol / L) and deionized water in sequence; the end-capping agent precursor (N-(4'-((4-fluorophenyl)sulfonyl)-[1,1'-biphenyl]-4-yl)acetamide) is obtained by recrystallization with ethanol for three times and drying, and the yield is 88%; corresponding to the chemical structural formula: R'= R'-2; X=F);

[0095] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.15 mol / L) and ethanol (0.15 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-2; X= F), with a yield of 95%;

[0096] (3) 0.02 mol of the end-capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorobenzophenone imine, 0.1 mol of 4,4'-dihydroxydiphenyl ether and 0.13 mol of potassium carbonate were added to sulfolane (solvent) at the same time; toluene was added, the temperature was raised to azeotropic (130 °C), toluene and water were kept under azeotropic reflux for 4 hours, and the toluene was exhausted; the temperature was raised to 210 °C and kept under azeotropic reflux for 4 hours; the material was discharged into ethanol and crushed; the product was washed with ethanol and water 3 times each, and dried to obtain amino-terminated polyetheretheretherketone imine (corresponding to the above chemical formula: NH2-PI-2; R=R-3);

[0097] (4) The amino-terminated polyetheretheretherketoneimine obtained in step (3) is dissolved in 1,4-dioxane (amino end group equivalent 0.1 mol / L); the above solution is added dropwise to an acetonitrile solution (0.1 mol / L) containing nitrite tetrafluoroborate with 1.5 times the amino end group equivalent; when the solution becomes a dark brown transparent solution, the material is discharged into ether, and the diazonium salt-terminated polyarylether is rapidly precipitated, filtered and washed with ether to obtain a diazonium salt-terminated polyetheretherketoneimine (corresponding to the above chemical formula: Dia-PI-2; R1=R1-3);

[0098] (5) The diazonium salt-terminated polyetheretheretherketimine (0.01 g / mL) obtained in step (4) and the supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) were dissolved in acetonitrile as an electrolyte; the carbon nanotube fiber was connected to the cathode of the electrolytic cell and immersed in the electrolyte; a reduction potential of -0.3 V was applied and maintained for 3 min; the electrochemically reduced carbon nanotubes were washed with acetonitrile and dried to obtain carbon nanotubes grafted with polyetheretheretherketimine (corresponding to the above chemical structure: PI-2; R2=R2-3);

[0099] (6) The carbon nanotubes grafted with polyetheretheretherketone imine obtained in step (5) were placed in acetone (0.05 g / mL), mechanically stirred and ultrasonically dispersed for 2 hours; under the conditions of mechanical stirring and ultrasonic dispersion, 2 M hydrochloric acid in an equal volume to acetone was added dropwise; under the conditions of mechanical stirring and ultrasonic dispersion, the temperature was raised to reflux and maintained for 24 hours; filtered, washed with deionized water for 3 times, and dried to obtain crystalline polyetheretheretherketone surface-grafted carbon nanotubes (corresponding to the above chemical structure: P-2; R2=R2-3).

[0100] Example 3: This example provides a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone), which specifically comprises the following steps:

[0101] (1) At -5 °C and under inert gas protection, 4-(4-acetylaminophenoxy)benzenesulfonyl chloride (0.1 mol) was fully dissolved in fluorobenzene (fluorobenzene was used as both solvent and reactant), and AlCl3 powder (0.12 mol) was added in 5 batches; the mixture was heated to room temperature and stirred for 3 hours; the mixture was heated to reflux and stirred for 8 hours; deionized water was added to azeotropic reflux to separate unreacted fluorobenzene; the mixture was filtered and the residue (crude product) was washed with NaOH solution (1 mol / L) and deionized water in sequence; the product was recrystallized three times with ethanol and dried to obtain the end-capping agent precursor (N-(4-(4-((4-fluorophenyl)sulfonyl)phenoxy)phenyl)acetamide, corresponding to the above chemical formula: R'= R'-3; X=F), with a yield of 85%;

[0102] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.25 mol / L) and ethanol (0.25 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenoxy)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-3; X= F), with a yield of 95%;

[0103] (3) 0.01 mol of the end-capping agent (4-fluoro-4'-(4-aminophenoxy)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorodiketone imine, 0.1 mol of 4,4'-dihydroxydiphenyl ether and 0.13 mol of potassium carbonate were added to cyclopentane sulfone (solvent) at the same time; toluene was added, the temperature was raised to azeotropic (130°C), and after maintaining the azeotropic reflux of toluene and water for 4 hours, the toluene was completely discharged; the temperature was raised to 210°C and maintained for 4 hours; the material was discharged into ethanol and crushed; the product was washed with ethanol and water 3 times each, and dried to obtain amino-terminated polyetheretheretherketoneketimine (corresponding to the above chemical formula: NH2-PI-6; R=R-2);

[0104] (4) Dissolve the amino-terminated polyether ether ether ketone ketimine obtained in step (3) in 1,4-dioxane (amino end group equivalent 0.01 mol / L); drop the above solution into a solution of nitrite tetrafluoroboric acid in acetonitrile (0.01 mol / L) containing 1.5 times the amino end group equivalent; when the solution body becomes a dark brown transparent solution, discharge into diethyl ether, and the diazonium salt-terminated polyether ether ether ketone ketimine is quickly precipitated, filtered and washed with diethyl ether to obtain the diazonium salt-terminated polyether ether ether ketone ketimine (corresponding to the above chemical formula: Dia-PI-6; R1=R1-2);

[0105] (5) Dissolve the diazonium salt-terminated polyether ether ether ketone ketimine (0.01 g / mL) obtained in step (4) and a supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) in acetonitrile as an electrolyte; connect the carbon nanotube paper (bucky paper) with the cathode of the electrolytic cell and immerse it in the electrolyte; apply a reduction potential of -0.3 V for 3 min; wash the electrochemically reduced carbon nanotube with acetonitrile and dry to obtain the carbon nanotube grafted with polyether ether ether ketone ketimine (corresponding to the above chemical formula: PI-6; R2=R2-2);

[0106] (6) Put the carbon nanotube grafted with polyether ether ether ketone ketimine obtained in step (5) into acetone (0.01 g / mL), mechanically stir and ultrasonically disperse for 2 hours; under the condition of mechanical stirring and ultrasonic dispersion, drop 2 M hydrochloric acid with the same volume of acetone; under the condition of mechanical stirring and ultrasonic dispersion, heat to reflux and maintain for 24 h; filter, wash with deionized water for 3 times, and dry to obtain the crystalline polyether ether ether ketone ketone surface grafted and modified carbon nanotube (corresponding to the above chemical formula: P-6; R2=R2-2).

[0107] Example 4: The embodiment provides a preparation method of a crystalline polyaryl ether ketone surface grafted carbon nanotube, which specifically comprises the following steps:

[0108] (1) Under the condition of -5 ℃ and inert gas protection, fully dissolve 4'-acetylamino-[1,1'-biphenyl]-4-sulfonyl chloride (0.1 mol) in fluorobenzene (fluorobenzene is used as a solvent and also as a reactant), and add AlCl3 powder (0.12 mol) in 5 batches; increase the temperature to room temperature, stir for 3 hours; increase the temperature to reflux, stir for 8 hours; add deionized water to separate the unreacted fluorobenzene by azeotropic reflux; filter, and wash the filter residue (crude product) with NaOH solution (1 mol / L) and deionized water in sequence; recrystallize with ethanol for three times and dry to obtain the end-capping agent precursor (N-(4'-((4-fluorophenyl)sulfonyl)-[1,1'-biphenyl]-4-yl)acetamide, corresponding to the above chemical formula: R'=R'-2; X=F), with a yield of 86%;

[0109] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.35 mol / L) and ethanol (0.35 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-2; X= F), with a yield of 95%;

[0110] (3) 0.01 mol of the end-capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorobenzophenone imine, 0.1 mol of 4,4'-dihydroxybenzophenone and 0.13 mol of potassium carbonate were added to sulfolane (solvent) at the same time; toluene was added, the temperature was raised to azeotropic (130°C), toluene and water were kept under azeotropic reflux for 4 hours, and the toluene was exhausted; the temperature was raised to 210°C and kept under azeotropic reflux for 4 hours; the material was discharged into ethanol and crushed; the product was washed with ethanol and water 3 times each, and dried to obtain amino-terminated polyetherketone imine (corresponding to the above chemical formula: NH2-PI-4; R=R-3);

[0111] (4) The amino-terminated polyetherketimine obtained in step (3) was dissolved in 1,4-dioxane (amino end group equivalent 0.01 mol / L); the above solution was added dropwise to an acetonitrile solution (0.01 mol / L) containing 1.5 times the amino end group equivalent of tetrafluoroborate nitrite; when the solution became a dark brown transparent solution, the material was discharged into ether, and the diazonium salt-terminated polyarylether was rapidly precipitated, filtered and washed with ether to obtain a diazonium salt-terminated polyetherketimine (corresponding to the above chemical formula: Dia-PI-4; R1=R1-3);

[0112] (5) The diazonium salt-terminated polyetherketimine (0.01 g / mL) obtained in step (4) and the supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) were dissolved in acetonitrile as the electrolyte; the carbon nanotube paper (buckypaper) was connected to the cathode of the electrolytic cell and immersed in the electrolyte; a reduction potential of -0.3 V was applied and maintained for 5 min; the electrochemically reduced carbon nanotubes were washed with acetonitrile and dried to obtain carbon nanotubes grafted with polyetherketimine (corresponding to the above chemical structure: PI-4; R2=R2-3);

[0113] (6) The carbon nanotubes grafted with polyetherketone imine obtained in step (5) were placed in acetone (0.01 g / mL), mechanically stirred and ultrasonically dispersed for 2 hours; under the conditions of mechanical stirring and ultrasonic dispersion, 2 M hydrochloric acid in an equal volume to acetone was added dropwise; under the conditions of mechanical stirring and ultrasonic dispersion, the temperature was raised to reflux and maintained for 24 hours; filtered, washed with deionized water three times, and dried to obtain crystalline polyetherketone surface-grafted carbon nanotubes (corresponding to the above chemical structure: P-4; R2=R2-3).

[0114] Example 5: This example provides a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone), which specifically comprises the following steps:

[0115] (1) At -5 °C and under inert gas protection, 4'-acetylamino-[1,1'-biphenyl]-4-sulfonyl fluoride (0.1 mol) was fully dissolved in fluorobenzene (fluorobenzene was used as both solvent and reactant), and AlCl3 powder (0.12 mol) was added in 5 batches; the mixture was heated to room temperature and stirred for 3 hours; the mixture was heated to reflux and stirred for 8 hours; deionized water was added to azeotropic reflux to separate unreacted fluorobenzene; the mixture was filtered and the residue (crude product) was washed with NaOH solution (1 mol / L) and deionized water in sequence; the product was recrystallized three times with ethanol and dried to obtain the end-capping agent precursor (N-(4'-((4-fluorophenyl)sulfonyl)-[1,1'-biphenyl]-4-yl)acetamide, corresponding to the above chemical formula: R'= R'-2; X= F), with a yield of 86%;

[0116] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.48 mol / L) and ethanol (0.48 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-2; X= F), with a yield of 95%;

[0117] (3) 0.01 mol of the end-capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorodiketone imine, 0.1 mol of hydroquinone and 0.13 mol of potassium carbonate were added to sulfolane (solvent) at the same time; toluene was added, the temperature was raised to azeotropic (130°C), toluene and water were kept under azeotropic reflux for 4 hours, and the toluene was exhausted; the temperature was raised to 210°C and kept under azeotropic reflux for 4 hours; the material was discharged into ethanol and crushed; the product was washed with ethanol and water 3 times each, and dried to obtain amino-terminated polyetheretherketoneketimine (corresponding to the above chemical formula: NH2-PI-5; R=R-3);

[0118] (4) Dissolve the amino-terminated polyether ether ketone ketimine obtained in step (3) in 1,4-dioxane (amino end group equivalent 0.01 mol / L); drop the above solution into a solution of nitrite tetrafluoroboric acid in acetonitrile (0.01 mol / L) containing 1.5 times the amino end group equivalent; when the solution turns into a dark brown transparent solution, discharge into diethyl ether, and the diazonium salt-terminated polyarylether is quickly precipitated, filtered and washed with diethyl ether to obtain diazonium salt-terminated polyether ether ketone ketimine (corresponding to the above chemical formula: Dia-PI-5; R1=R1-3);

[0119] (5) Dissolve the diazonium salt-terminated polyether ether ketone ketimine (0.01 g / mL) obtained in step (4) and a supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) in acetonitrile as an electrolyte; connect the carbon nanotube paper (bucky paper) to the cathode of the electrolytic cell and immerse it in the electrolyte; apply a reduction potential of -0.3 V for 4 min; wash the electrochemically reduced carbon nanotube with acetonitrile and dry to obtain a carbon nanotube grafted with polyether ether ketone ketimine (corresponding to the above chemical formula: PI-5; R2-=R2-3);

[0120] (6) Disperse the carbon nanotube grafted with polyether ether ketone ketimine obtained in step (5) in acetone (0.01 g / mL) under mechanical stirring and ultrasonic dispersion for 2 hours; drop 2 M hydrochloric acid in an equal volume of acetone under the condition of mechanical stirring and ultrasonic dispersion; heat to reflux under the condition of mechanical stirring and ultrasonic dispersion for 24 h; filter and wash with deionized water for 3 times, and dry to obtain a crystalline polyether ether ketone ketimine surface grafted and modified carbon nanotube (corresponding to the above chemical formula: P-5; R2=R2-3).

[0121] Example 6: The embodiment provides a preparation method of a crystalline polyarylether ketone surface grafted carbon nanotube, which specifically comprises the following steps:

[0122] (1) Dissolve 4'-acetamido-[1,1'-biphenyl]-4-sulfonyl fluoride (0.1 mol) in fluorobenzene (fluorobenzene is used as a solvent and also as a reactant) under the condition of -5 ℃ and inert gas protection, and add AlCl3 powder (0.12 mol) in 5 batches; increase the temperature to room temperature and stir for 3 hours; increase the temperature to reflux and stir for 8 hours; add deionized water to separate the unreacted fluorobenzene by azeotropic reflux; filter and wash the filter residue (crude product) with NaOH solution (1 mol / L) and deionized water in sequence; recrystallize with ethanol for 3 times and dry to obtain a capping agent precursor (N-(4'-((4-fluorophenyl)sulfonyl)-[1,1'-biphenyl]-4-yl)acetamide, corresponding to the above chemical formula: R'=R'-2; X=F), with a yield of 86%;

[0123] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.56 mol / L) and ethanol (0.56 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-2; X= F), with a yield of 95%;

[0124] (3) 0.01 mol of the end-capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorobenzophenone imine, 0.1 mol of biphenyl diphenol and 0.13 mol of potassium carbonate were added to cyclopentane (solvent); toluene was added, the temperature was raised to azeotropic (130°C), and after maintaining the azeotropic reflux of toluene and water for 4 hours, the toluene was exhausted; the temperature was raised to 210°C and maintained for 4 hours; the material was discharged into ethanol and crushed; it was washed with ethanol and water 3 times each, and dried to obtain amino-terminated biphenyl type polyetheretherketone imine (corresponding to the above chemical formula: NH2-PI-3; R=R-3);

[0125] (4) The amino-terminated biphenyl-type polyetheretherketone imine obtained in step (3) is dissolved in 1,4-dioxane (amino end group equivalent 0.01 mol / L); the above solution is added dropwise to an acetonitrile solution (0.01 mol / L) containing 1.5 times the amino end group equivalent of tetrafluoroborate nitrite; when the solution becomes a dark brown transparent solution, the material is discharged into ether, and the diazonium salt-terminated polyarylether is rapidly precipitated, filtered and washed with ether to obtain a diazonium salt-terminated biphenyl-type polyetheretherketone imine (corresponding to the above chemical formula: Dia-PI-3; R1=R1-3);

[0126] (5) The diazonium salt-terminated biphenyl-type polyetheretherketone imine (0.01 g / mL) obtained in step (4) and the supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) were dissolved in acetonitrile as an electrolyte; the carbon nanotube paper (bucky paper) was connected to the cathode of the electrolytic cell and immersed in the electrolyte; a reduction potential of -0.3 V was applied and maintained for 3 min; the electrochemically reduced carbon nanotubes were washed with acetonitrile and dried to obtain carbon nanotubes grafted with biphenyl-type polyetheretherketone imine (corresponding to the above chemical structure: PI-3; R2=R2-3);

[0127] (6) The carbon nanotubes grafted with biphenyl polyetheretherketone imine obtained in step (5) were placed in acetone (0.01 g / mL), mechanically stirred and ultrasonically dispersed for 2 hours; under the conditions of mechanical stirring and ultrasonic dispersion, 2M hydrochloric acid in an equal volume to acetone was added dropwise; under the conditions of mechanical stirring and ultrasonic dispersion, the temperature was raised to reflux and maintained for 24 hours; filtered, washed with deionized water for 3 times, and dried to obtain crystalline biphenyl polyetheretherketone surface-grafted modified carbon nanotubes (corresponding to the above chemical structure: P-3; R2=R2-3).

[0128] Example 7: This example provides a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone), which specifically comprises the following steps:

[0129] (1) At -5 °C and under inert gas protection, 4'-acetylamino-[1,1'-biphenyl]-4-sulfonyl fluoride (0.1 mol) was fully dissolved in fluorobenzene (fluorobenzene served as both solvent and reactant), and AlCl3 powder (0.12 mol) was added in 5 batches; the temperature was raised to room temperature and stirred for 3 hours; the temperature was raised to reflux and stirred for 8 hours; deionized water was added to azeotropic reflux to separate unreacted fluorobenzene; the filter was filtered and the residue (crude product) was washed with NaOH solution (1 mol / L) and deionized water in sequence; the end-capping agent precursor (N-(4'-((4-fluorophenyl)sulfonyl)-[1,1'-biphenyl]-4-yl)acetamide, corresponding to the above chemical formula: R'= R'-2; X=F) was obtained with a yield of 86%.

[0130] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.59 mol / L) and ethanol (0.59 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-2; X= F), with a yield of 95%;

[0131] (3) 0.01 mol of the end-capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorodiketone imine, 0.1 mol of biphenyl diphenol and 0.13 mol of potassium carbonate were added to cyclopentane (solvent); toluene was added, the temperature was raised to azeotropic (130°C), and after maintaining the azeotropic reflux of toluene and water for 4 hours, the toluene was exhausted; the temperature was raised to 210°C and maintained for 4 hours; the material was discharged into ethanol and crushed; it was washed with ethanol and water 3 times each, and dried to obtain amino-terminated biphenyl type polyether ether ketone ketimine (corresponding to the above chemical formula: NH2-PI-7; R = R-3);

[0132] (4) The amino-terminated biphenyl polyetheretherketoneketimine obtained in step (3) was dissolved in 1,4-dioxane (amino end group equivalent 0.01 mol / L); the above solution was added dropwise to an acetonitrile solution (0.01 mol / L) containing 1.5 times the amino end group equivalent of tetrafluoroborate nitrite; when the solution became a dark brown transparent solution, the material was discharged into ether, and the diazonium salt-terminated polyarylether was rapidly precipitated, filtered and washed with ether to obtain a diazonium salt-terminated biphenyl polyetheretherketoneketimine (corresponding to the above chemical formula: Dia-PI-7; R1=R1-3);

[0133] (5) The diazonium salt-terminated biphenyl-type polyetheretherketoneketimine (0.01 g / mL) obtained in step (4) and the supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) were dissolved in acetonitrile as an electrolyte; the carbon nanotube paper (buckypaper) was connected to the cathode of the electrolytic cell and immersed in the electrolyte; a reduction potential of -0.3 V was applied and maintained for 3 min; the electrochemically reduced carbon nanotubes were washed with acetonitrile and dried to obtain carbon nanotubes grafted with biphenyl-type polyetheretherketoneketimine (corresponding to the above chemical structure: PI-7; R2-=R2-3);

[0134] (6) The carbon nanotubes grafted with biphenyl-type polyetheretherketoneketimine obtained in step (5) were placed in acetone (0.01 g / mL), mechanically stirred and ultrasonically dispersed for 2 hours; under the conditions of mechanical stirring and ultrasonic dispersion, 2M hydrochloric acid in an equal volume to acetone was added dropwise; under the conditions of mechanical stirring and ultrasonic dispersion, the temperature was raised to reflux and maintained for 24 hours; filtered, washed with deionized water for 3 times, and dried to obtain crystalline biphenyl-type polyetheretherketoneketone surface-grafted modified carbon nanotubes (corresponding to the above chemical structure: P-7; R2=R2-3).

[0135] Example 8: This example provides a method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone), which specifically comprises the following steps:

[0136] (1) At -5 °C and under inert gas protection, 4'-acetylamino-[1,1'-biphenyl]-4-sulfonyl fluoride (0.1 mol) was fully dissolved in fluorobenzene (fluorobenzene was used as both solvent and reactant), and AlCl3 powder (0.12 mol) was added in 5 batches; the mixture was heated to room temperature and stirred for 3 hours; the mixture was heated to reflux and stirred for 8 hours; deionized water was added to azeotropic reflux to separate unreacted fluorobenzene; the mixture was filtered and the residue (crude product) was washed with NaOH solution (1 mol / L) and deionized water in sequence; the product was recrystallized three times with ethanol and dried to obtain the end-capping agent precursor (N-(4'-((4-fluorophenyl)sulfonyl)-[1,1'-biphenyl]-4-yl)acetamide, corresponding to the above chemical formula: R'= R'-2; X=F), with a yield of 86%;

[0137] (2) The capping agent precursor obtained in step (1) was dissolved in a mixture of concentrated hydrochloric acid (0.7 mol / L) and ethanol (0.7 mol / L) and refluxed overnight; then extracted with ethyl acetate (80 mL×3), the organic phases were combined and dried over anhydrous sodium sulfate; filtered, the filtrate was collected and the solvent was removed to obtain the capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone, corresponding to the above chemical formula: R''= R''-2; X=F), with a yield of 95%;

[0138] (3) 0.01 mol of the end-capping agent (4-fluoro-4'-(4-aminophenyl)diphenyl sulfone) obtained in step (2), 0.1 mol of 4,4'-difluorodiketone imine, 0.1 mol of 4,4'-dihydroxybenzophenone and 0.13 mol of potassium carbonate were added to sulfolane (solvent) at the same time; toluene was added, the temperature was raised to azeotropic (130°C), toluene and water were kept under azeotropic reflux for 4 hours, and the toluene was exhausted; the temperature was raised to 210°C and kept under azeotropic reflux for 4 hours; the material was discharged into ethanol and crushed; the product was washed with ethanol and water 3 times each, and dried to obtain amino-terminated polyetherketoneetherketoneketimine (corresponding to the above chemical formula: NH2-PI-8; R=R-3);

[0139] (4) The amino-terminated polyetherketoneetherketoneketimine obtained in step (3) is dissolved in 1,4-dioxane (amino end group equivalent 0.01 mol / L); the above solution is added dropwise to an acetonitrile solution (0.01 mol / L) containing nitrite tetrafluoroborate with 1.5 times the amino end group equivalent; when the solution becomes a dark brown transparent solution, the material is discharged into ether, and the diazonium salt-terminated polyarylether is rapidly precipitated, filtered and washed with ether to obtain a diazonium salt-terminated polyetherketoneetherketoneketimine (corresponding to the above chemical formula: Dia-PI-8; R1=R1-3);

[0140] (5) The diazonium salt-terminated poly(ether ketone ether ketone ketone imine) obtained in step (4) (0.01 g / mL) and supporting electrolyte (tetrabutylammonium tetrafluoroborate, 1 mM) were dissolved in acetonitrile as an electrolyte; the carbon nanotube paper (bucky paper) was connected to the cathode of the electrolytic cell and immersed in the electrolyte; a reduction potential of -0.3 V was applied and maintained for 3 min; the electrochemically reduced carbon nanotubes were washed with acetonitrile and dried to obtain carbon nanotubes grafted with poly(ether ketone ether ketone ketone imine) (corresponding to the above chemical formula: PI-8; R2=R2-3);

[0141] (6) The carbon nanotubes grafted with polyetherketoneetherketoneketimine obtained in step (5) were placed in acetone (0.01 g / mL), mechanically stirred and ultrasonically dispersed for 2 hours; under the conditions of mechanical stirring and ultrasonic dispersion, 2 M hydrochloric acid in an equal volume to acetone was added dropwise; under the conditions of mechanical stirring and ultrasonic dispersion, the temperature was raised to reflux and maintained for 24 hours; filtered, washed with deionized water for 3 times, and dried to obtain crystalline polyetherketoneetherketoneketone surface-grafted modified carbon nanotubes (corresponding to the above chemical structure: P-8; R2-=R2-3).

[0142] Based on the above-mentioned ideal embodiment of the present invention, and through the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of the present invention. The technical scope of the present invention is not limited to the contents of the specification.

Claims

1. A method for preparing carbon nanotubes grafted onto the surface of crystalline polyaryletherketone, characterized in that: The following steps are involved: The amide-containing sulfonyl halide compound and halogenated benzene are subjected to sulfonation reaction and acid hydrolysis reaction in sequence to obtain an amino-terminated agent containing a sulfone group; An amino-terminated agent containing a sulfone group, a difluoro monomer, a bisphenol monomer, and potassium carbonate are placed in sulfolane to carry out a polymerization reaction to obtain an amino-terminated polyarylether; The amino-terminated polyarylether is reacted with nitrosotetrafluoroborate to obtain a diazonium salt-terminated polyarylether; The diazonium salt-capped polyarylether is prepared into an electrolyte, the carbon nanotubes are connected to a cathode, and immersed in the electrolyte containing the diazonium salt-capped polyarylether, and a reduction potential is applied to react to obtain carbon nanotubes grafted with the polyarylether; The carbon nanotubes grafted with polyarylether are subjected to hydrolysis reaction in an acidic environment to obtain crystalline polyaryletherketone surface-grafted carbon nanotubes.

2. The method for preparing crystalline polyaryletherketone surface-grafted carbon nanotubes according to claim 1, characterized in that: The halogenated benzene is chlorobenzene or fluorobenzene.

3. The method for preparing crystalline polyaryletherketone surface-grafted carbon nanotubes according to claim 1 or 2, characterized in that: The step of sequentially subjecting an amide-containing sulfonyl halide compound and a halogenated benzene to a sulfonation reaction and an acidolysis reaction to obtain an amino end-capping agent containing a sulfone group specifically comprises: Under the condition of no more than -5°C and inert gas protection, the amide-containing sulfonyl halide compound is fully dissolved in halogenated benzene, and AlCl3 powder is added in batches; then the temperature is raised to room temperature and stirred; the temperature is further raised to reflux; deionized water is added to azeotropic reflux to separate the unreacted halogenated benzene; the crude product is filtered and the filter residue is washed to obtain a crude product; the crude product is recrystallized three times with ethanol and dried to obtain a capping agent precursor; The capping agent precursor is dissolved in a mixture of concentrated hydrochloric acid and ethanol and refluxed; then extracted with ethyl acetate, the organic phases are combined and dried over anhydrous sodium sulfate; then filtered and concentrated to obtain an amino capping agent containing a sulfone group.

4. The method for preparing crystalline polyaryletherketone surface-grafted carbon nanotubes according to claim 1, characterized in that: The difluoro monomer is 4,4'-difluorobenzophenone imine and / or difluorodiketone imine; the bisphenol monomer is at least one of hydroquinone, biphenol, 4,4'-dihydroxybenzophenone and 4,4'-dihydroxydiphenyl ether.

5. The method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone) according to claim 1 or 4, characterized in that: The step of placing an amino-terminated agent containing a sulfone group, a difluoro monomer, a bisphenol monomer, and potassium carbonate in sulfolane for polymerization to obtain an amino-terminated polyarylene ether specifically comprises: An amino-terminated agent containing a sulfone group, a difluoro monomer, a bisphenol monomer, and potassium carbonate are added simultaneously to sulfolane; toluene is then added, the temperature is raised to azeotropic, and after toluene is maintained at reflux for a certain period of time, the toluene is completely discharged; the temperature is continued to be raised to no less than 210°C for reaction; the material is then discharged into ethanol, crushed, washed, and dried to obtain an amino-terminated polyarylene ether.

6. The method for preparing crystalline poly(aryletherketone) surface-grafted carbon nanotubes according to claim 1, characterized in that: The step of subjecting the amino-terminated polyarylene ether to a diazonium salt reaction with nitrosotetrafluoroborate to obtain the diazonium salt-terminated polyarylene ether specifically comprises: The amino-terminated polyarylether is dissolved in 1,4-dioxane; the above solution is added dropwise into an acetonitrile solution containing nitrite tetrafluoroborate; when the solution becomes a dark brown transparent solution, the material is discharged into ether, and the diazonium-terminated polyarylether is quickly precipitated, which is filtered and washed with ether to obtain the diazonium-terminated polyarylether.

7. The method for preparing crystalline poly(aryletherketone) surface-grafted carbon nanotubes according to claim 1, characterized in that: The steps of preparing an electrolyte containing diazonium salt-capped polyarylene ether, connecting carbon nanotubes to a cathode, immersing the carbon nanotubes in the electrolyte containing the diazonium salt-capped polyarylene ether, and applying a reducing potential to react to obtain carbon nanotubes grafted with polyarylene ether include: The diazonium salt-terminated polyarylether and supporting electrolyte are dissolved in acetonitrile to prepare an electrolyte solution; The carbon nanotubes are connected to a cathode, immersed in an electrolyte, and subjected to a reduction potential for reaction. The electrochemically reduced carbon nanotubes are washed with acetonitrile and dried to obtain carbon nanotubes grafted with polyarylene ether.

8. The method for preparing carbon nanotubes grafted onto the surface of crystalline poly(aryletherketone) according to claim 7, characterized in that: The supporting electrolyte is tetrabutylammonium tetrafluoroborate.

9. The method for preparing crystalline poly(aryletherketone) surface-grafted carbon nanotubes according to claim 1, characterized in that: The step of hydrolyzing the carbon nanotubes grafted with polyarylether in an acidic environment to obtain crystalline polyaryletherketone surface-grafted carbon nanotubes specifically comprises: The carbon nanotubes grafted with polyarylether are placed in acetone, mechanically stirred and ultrasonically dispersed; then, hydrochloric acid is added dropwise under the conditions of mechanical stirring and ultrasonic dispersion, and the temperature is raised to reflux; then, the carbon nanotubes grafted with crystalline polyaryletherketone are obtained by filtering, washing and drying.

10. A crystalline polyaryletherketone surface-grafted carbon nanotube prepared by the preparation method according to any one of claims 1 to 9.

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