CN1209382C - Preparation method of block polymer grafted earbon nano-pipe - Google Patents

Abstract

The present invention provides a preparation method of carbon nanotubes in which block polymers are grafted. After being acidified and acylated, the carbon nanotubes react with polyol or polyamine so that hydroxyl or amino groups are attached to the surfaces of the carbon nanotubes. Then, the carbon nanotubes react with alpha-halogen acyl halide to obtain carbon nanotubes whose surfaces have initiation groups; then, monomers containing double bonds are initiated to be polymerized by atom transfer free radical polymerization reactions under the existence of catalysts and ligands to obtain carbon nanotubes in which single-segment macromolecules are grafted; the polymerization of another kind of monomers containing double bonds continues to be initiated by the carbon nanotubes in which single-segment macromolecules are grafted through the atom transfer free radical polymerization reactions to obtain the carbon nanotubes in which block polymers are grafted. Obtained products have good dissolubility, are capable of absorbing microparticles with different characteristics, are easy to be added to plastics, rubber, paint or fibers to prepare high-performance film materials, high-strength fiber materials, wave absorbing fiber materials, and have wide application prospect.

Description

Preparation method of block polymer grafted carbon nanotubes

Technical field: the present invention relates to a preparation method of surface-modified carbon nanotubes, especially a preparation method of block polymer-grafted carbon nanotubes.

Background technology: The preparation methods of carbon nanotubes (Carbon Nanotube, referred to as CNT) mainly include catalytic pyrolysis, arc discharge, template method and laser evaporation. The prepared carbon nanotubes are divided into single-wall nanotubes (SWNT) and multi-wall carbon nanotubes (Multi-wall Nanotube, MWNT). Carbon nanotube/polymer nanocomposites have been developed due to their excellent properties. The preparation of carbon nanotubes/polymer nanocomposites is divided into two ways, one is to mechanically disperse carbon nanotubes into polymers, which is called "blending"; the other is to disperse carbon nanotubes on the surface After the functional groups are connected, in-situ polymerization is carried out to obtain carbon nanotube/polymer nanocomposite materials connected by covalent bonds. The latter method can greatly improve the affinity and solubility of carbon nanotubes, thereby preparing high-performance nanocomposites.

Richard E.Smalley and others studied the acid treatment of carbon nanotubes carefully in 1998, and obtained the product distribution under different treatment conditions, which laid a good foundation for further research in the future (Science, 1998, 280 (22 ): 1253-1255). Later, Masahito Sano et al. successfully grafted the tenth generation dendritic polymer PAMAM (poly(amidoamine)) onto the surface of carbon nanotubes (Angew. Chem. 2001, 113(24): 4797-4799). Glucosamine has also been successfully grafted onto the surface of carbon nanotubes to obtain carbon nanotubes with good water solubility (Pompeo, F.; Resasco, DE, Nano Letters, vol 0 no 0 AE). Ya-PingSun and others have done a lot of work in this area, and have realized PPEI-EI (poly(propionyethylenemine-co-ethylenemine), M _w ≈200 000, EI mole fraction ≈15%) (J.Am.Chem.Soc .2000, 122(24), 5878-5880; J.Phys.Chem.B 2000, 104(30), 7071-7076; Nano Lett., 2001, 1(8), 423-427) and some dendrimers Grafting of (Nano Lett., 2001, 1(8), 439-441; Chem.Mater.2001, 13(9): 2864-2869; J.Phys.Chem.B 2002, 106(6), 1294- 1298), and studied the nonlinear optical properties of the obtained products.

On the other hand, almost simultaneously and independently, Sawamoto and Matyjaszewski discovered a transition metal-catalyzed "living" controllable free radical polymerization called atom transfer radical polymerization (ATRP). This method soon became a research hotspot in international polymer chemistry, and was hailed as "a new research method in the 21st century". This method is much better than the traditional polymerization method in terms of controlling the target product and maintaining a low molecular weight distribution index, and also avoids the harsh requirements on the polymerization environment in the traditional method. At the same time, due to the wide range of initiators, especially the participation of initiators with functional groups, functional groups can be conveniently introduced into the product, and various block polymers can also be synthesized. Using the ATRP method, Walt et al. grafted polymethyl methacrylate onto the gold surface to prepare core-shell gold nanoparticles (Mandal, T.K.; Fleming, M.S.; Walt D.R. Nano Letters, Vol.2, 3-7 (2002)).

Summary of the invention: The purpose of the present invention is to prepare block polymer-grafted carbon nanotubes by means of molecular design and atom transfer radical polymerization, so as to meet the needs of different application fields.

The content of the invention is to synthesize a series of block polymer grafted carbon nanotubes by using carbon nanotubes as raw materials. The carbon nanotube surface of the present invention has a large number of polymers, and the polymer has different functional groups. The length of the polymer molecular chain can be effectively controlled by changing the ratio of the initiation center and the monomer. The grafting degree of the carbon nanotube surface It can be controlled by the degree of acidification treatment of carbon nanotubes, and the types of functional groups can be controlled by adding monomers containing different functional groups, so that new polymer-grafted carbon nanotubes with multiple functions can be prepared.

The specific preparation method of the carbon nanotube grafted by the block polymer of the present invention is as follows:

Step (a): Add 1 to 10 g of dry carbon nanotube raw material and 5 to 50 mL of strong oxidizing acid in a flask, ultrasonically treat at 40 to 100 kHz for 30 min to 100 hr, then heat to 20 to 200 ° C, stir and reflux for 0.5 ~100hr, filter with filter membrane, wash repeatedly until neutral, vacuum dry at 80~180℃ for 10~30hr to obtain acidified carbon nanotubes;

Step (b): Add 1-10 g of acidified carbon nanotubes obtained in step (a) and 1-100 g of acylating agent into a flask, and after ultrasonic treatment at 40-100 kHz for 10-1000 min, heat to 20-200 ° C, stir and reflux React for 0.5-100 hours, filter with suction and wash repeatedly to remove the acylating agent, and obtain acylated carbon nanotubes;

Step (c): Add 1 to 10 g of acylated carbon nanotubes obtained in step (b) and 1 to 50 g of polyhydric alcohols or polyamines into the flask, seal it, pump and fill the flask with nitrogen repeatedly three times, and process it with 40 to 100 kHz ultrasonic waves for 10 to 50 g. After 1000 minutes, react at 20-200°C for 1-20 hours, filter with suction, wash repeatedly, and dry in vacuum at 80-180°C to obtain carbon nanotubes with hydroxyl or amine groups on the surface;

Step (d): Add 1 to 10 g of carbon nanotubes with hydroxyl or amino groups on the surface obtained in step (c) and 1 to 50 g of α-haloacyl halides in the flask, seal it, and repeatedly pump nitrogen for three times, with 40 to 40 g After 100kHz ultrasonic treatment for 10-1000min, react at 20-200°C for 1-20hr, suction filter, wash, and vacuum-dry at 80-180°C to obtain carbon nanotubes with initiating groups on the surface;

Step (e): Add 0.6 to 5 g of catalyst and 0.7 to 5 g of ligand in the flask, then add 1 to 10 g of carbon nanotubes with initiating groups on the surface obtained in step (d), and 10 to 50 mL of solvent, and fill the flask with Ar or N ₂ for 1-100min, add 10-80mL of monomer containing double bonds, continue to fill with nitrogen or argon for 1-100min, react at 60-150℃ for 20-1000hr, after the viscosity increases significantly, stop the reaction, Precipitate in medium, redissolve the obtained precipitate in a solvent, suction filter, wash, and vacuum dry at 80-180°C to obtain single-stage polymer-grafted carbon nanotubes;

Step (f): Add 0.4 to 5 g of catalyst and 0.48 to 5 g of ligand in the flask, then add 2 to 10 g of single-stage polymer-grafted carbon nanotubes obtained in step (e), and 10 to 50 mL of solvent, and fill the flask with Ar or N ₂ for 1-100min, add 10-80mL of another double bond-containing monomer, continue to fill with nitrogen or argon for 1-100min, react at 50-150℃ for 10-1000hr, stop the reaction after the viscosity increases significantly , precipitate in methanol, redissolve the obtained precipitate in a solvent, suction filter, wash, and vacuum dry at 80-180° C. to obtain block polymer-grafted carbon nanotubes.

The carbon nanotubes used in step (a) of the method of the present invention are single-wall or multi-wall carbon nanotubes prepared by methods such as catalytic pyrolysis, arc discharge, template method and laser evaporation (CVD).

The strong oxidizing acid used in step (a) of the method of the present invention includes 60-70% nitric acid, sulfuric acid, and 1/100-100/1 ratio of nitric acid/sulfuric acid mixed acid.

The acylating agent used in step (b) of the method of the present invention includes phosphorus trichloride, phosphorus pentachloride, thionyl chloride, phosphorus tribromide, phosphorus pentabromide, and thionyl bromide.

The polyols or polyamines used in the method step (c) of the present invention include ethylene glycol, glycerol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2 -Butanediol, 1,3-butanediol, butanetriol, polyethylene glycol, ethylenediamine, propylenetriamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4- Butanediamine, 1,2-butanediamine, 1,3-butanediamine, butanetriamine, polyethylenediamine and all organic compounds containing two or more hydroxyl groups and amino groups.

In the method steps (c) and (d) of the present invention, no solvent is used or dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2- Pyrrolidone, chloroform, tetrahydrofuran, ethyl acetate, acetone, acetonitrile, butanone, triethylamine, pyridine, dimethylaminopyridine are solvents or mixed solvents containing these solvents are reaction media.

The α-haloacyl halides used in step (d) of the method of the present invention include α-bromobutyryl bromide, α-bromoisobutyryl bromide, α-bromopropionyl bromide, α-chlorobutyryl chloride, α- Chloroisobutyryl chloride, α-chloropropionyl chloride.

Double bond-containing monomers in the method steps (e) and (f) of the present invention are free radical polymerizable monomers, including hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate Ester, hydroxybutyl acrylate, hydroxybutyl methacrylate, methyl acrylate, methyl methacrylate, aminoethyl acrylate, aminoethyl methacrylate, N,N-aminoethyl methacrylate, N, N-Dimethyl-aminoethyl methacrylate, styrene, p-chloromethylstyrene, m-chloromethylstyrene, acrylamide, N,N-dimethylacrylamide, methacrylamide, N, N-Dimethyl-methacrylamide, N-isopropylacrylamide, N-isopropyl-methacrylamide, N,N-diethylacrylamide, N,N-diethyl-methyl Acrylamide, N,N-dihydroxyethylacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylmethacrylamide, N-(trimethylol)methacrylamide, N-aminoethyl Acrylamide, N-aminoethyl-methacrylamide, N-(2-dimethylamino)ethylacrylamide, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate Ester, hydroxybutyl acrylate, hydroxybutyl methacrylate, N, N-dihydroxyethylacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylmethacrylamide, N-(trimethylol ) methacrylamide.

Catalyst used in the method step (e) of the present invention, (f) is to contain Cu(I), Fe(I), Mo(V), Re(V), Ru(II), Ni(I), Pb(II) Metal compounds such as cuprous chloride, cuprous bromide, ferrous chloride, ferrous bromide, lithium molybdate, ReO ₂ I(PPh ₃ ) ₂ , RuCl ₂ , Ni(NCN)Br, Pd(OAc) ₁ , etc.; the ligands used are 2-bipyridine, tetramethylethylenediamine, pentamethyl-diethyltriamine, hexamethyl-triethylenetetramine, oxalic acid, malonic acid, succinic acid , phthalic acid, triphenylphosphine, tri-n-butylphosphine, etc.; the solvents used are dimethylsulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-form 2-pyrrolidone, chloroform, dichloromethane, dichloroethane, tetrahydrofuran, ethyl acetate, acetone, methyl ethyl ketone, acetonitrile, propanol, ethanol, methanol or a mixture containing these solvents.

The morphology of carbon nanotubes grafted with block polymers was analyzed by high-magnification SEM, and the internal structure was tested by high-magnification TEM. In addition, the carbon nanotubes grafted by block polymers were also characterized by nuclear magnetic resonance, infrared spectroscopy, and thermal analysis. .

The block polymer-grafted carbon nanotubes prepared according to the present invention have two or more polymer molecular chains with different affinities, have excellent solubility, and can adsorb microparticles of different properties in the solution , suitable for biomedical carriers and special functional materials; using the properties of different chain segments can greatly expand the application of carbon nanotubes in the mesoscopic field; at the same time, this kind of carbon nanotubes also has a good absorption effect on microwaves and is easy to add In plastics, rubber, coatings and fibers, it can also be formed into a film alone. It is suitable for the body or additive of high-strength special materials, high-performance film materials, high-strength fiber materials, and microwave-absorbing fiber materials. It has a very broad application prospect.

Description of drawings:

Figure 1: SEM comparison of carbon nanotube single-segment grafted PMMA (A) and block-grafted PMMA-PHEMA (B)

Figure 2: ¹ H NMR image of carbon nanotube grafted PMMA-PHEMA

Specific embodiments: the following examples are further descriptions of the present invention, rather than limiting the scope of the present invention.

Example 1: Multi-walled carbon nanotubes prepared by catalytic pyrolysis as the initial raw material, after acidification and acylation, were connected with ethylene glycol, then reacted with α-bromoisobutyryl bromide, and grafted by ATRP method Polymethyl methacrylate (PMMA), and then continue to connect polyhydroxyethyl methacrylate (PHEMA) by ATRP method to obtain carbon nanotubes grafted by block polymer PMMA-PHEMA.

Step (a): In a 100mL single-neck round bottom flask equipped with a magnetic stirring rotor, add 2g of dry carbon nanotube raw material and 20mL of 60% concentrated nitric acid, heat to 120°C after ultrasonic treatment at 40kHz for 30min, stir and reflux React for 24 hours, filter with φ0.22 μm polytetrafluoroethylene microporous membrane, wash repeatedly with deionized water until neutral, and vacuum dry at 80°C for 24 hours to obtain acidified carbon nanotubes;

Step (b): Add 1.5 g of acidified carbon nanotubes obtained in step (a) and 8 g of thionyl chloride into a 100 mL single-necked round-bottom flask equipped with a magnetic stirring rotor, and heat to 60 ° C after ultrasonic treatment at 40 kHz for 30 min , stirred and reacted under reflux for 24hr, suction filtered and repeatedly washed to remove thionyl chloride, to obtain acylated carbon nanotubes;

Step (c): In a 100mL single-neck round bottom flask equipped with a magnetic stirring rotor, add 1.3g of acylated carbon nanotubes obtained in step (b) and 25g of ethylene glycol, seal with a reversible rubber stopper, and pump repeatedly Nitrogen three times, after ultrasonic treatment at 40kHz for 30min, react at 100°C for 24hr, remove unreacted substances and reaction by-products by suction filtration, wash with deionized water repeatedly, and vacuum dry at 80°C to obtain carbon nanotubes with hydroxyl groups on the surface ;

Step (d): In the 100mL single-neck round bottom flask equipped with a magnetic stirring rotor, add 1.1 g of carbon nanotubes with hydroxyl groups on the surface obtained in step (c) and 1 g of α-bromoisobutyryl bromide, Seal the mouth with a rubber stopper, pump nitrogen repeatedly three times, treat with 40kHz ultrasonic wave for 30min, react at 20°C for 1-20hr, remove unreacted substances and reaction by-products by suction filtration, wash with deionized water repeatedly, and vacuum-dry at 80°C. Obtain carbon nanotubes with initiating groups on the surface;

Step (e): In a 50mL single-necked round bottom flask equipped with a magnetic stirring rotor, add 0.6g CuBr, 0.7g ligand PMDETA (pentamethyl-diethyltriamine), and then add the obtained 1g of carbon nanotubes with initiator groups on the surface, solvent DMF 10mL, filled with N ₂ for 10min after sealing, added 10mL of methyl methacrylate MMA monomer, continued to fill with N ₂ for 10min, reacted at 60°C for 20hr, the viscosity was After a significant increase, stop the reaction, precipitate in methanol, redissolve the resulting precipitate in chloroform, filter with suction, wash, remove unreacted monomers and catalysts, etc., and dry under vacuum at 80°C to obtain single-section PMMA-grafted carbon nanotubes. 3 g of substance were obtained;

Step (f): In a 50mL single-neck round bottom flask equipped with a magnetic stirring rotor, add 0.4g CuBr, 0.48g ligand PMDETA, and then add the single-section polymer-grafted carbon nanotubes obtained in step (e) 2g, solvent DMF 10mL, after sealing, fill with N ₂ for 10min, add 10mL of hydroxyethyl methacrylate HEMA monomer, continue to fill with N ₂ for 10min, react at 50°C for 10hr, after the viscosity increases significantly, stop the reaction, in methanol Precipitate, redissolve the obtained precipitate in DMF, suction filter, wash, remove unreacted monomers and catalysts, etc., and vacuum dry at 80°C to obtain block PMMA-PHEMA grafted carbon nanotubes.

The results of SEM analysis are shown in Figure 1: Figure A on the left shows the surface appearance of carbon nanotubes grafted with PMMA. It can be seen that there is a thin layer of polymer covered on the surface. The diameter of nanotubes (average 20-24nm) increases slightly, and the shape of carbon nanotubes can be distinguished. B is the appearance of the grafted block PMMA-PHEMA, it can be seen that the appearance has changed, and the average diameter reaches 40nm. This demonstrates the successful grafting of block polymers. ^{The 1} H NMR results are shown in Figure 2, d is the characteristic peak of PMMA, b, c, e are the characteristic peaks of PHEMA.

Claims (11)

1. the preparation method of the carbon nanotube of block polymer grafting, it is characterized in that concrete preparation method is as follows: Step (a): Add 1 to 10 g of dry carbon nanotube raw material and 5 to 50 mL of strong oxidizing acid in a flask, ultrasonically treat at 40 to 100 kHz for 30 min to 100 hr, then heat to 20 to 200 ° C, stir and reflux for 0.5 ~100hr, filter with filter membrane, wash repeatedly until neutral, vacuum dry at 80~180℃ for 10~30hr to obtain acidified carbon nanotubes; Step (b): Add 1-10 g of acidified carbon nanotubes obtained in step (a) and 1-100 g of acylating agent into a flask, and after ultrasonic treatment at 40-100 kHz for 10-1000 min, heat to 20-200 ° C, stir and reflux React for 0.5-100 hours, filter with suction and wash repeatedly to remove the acylating agent, and obtain acylated carbon nanotubes; Step (c): Add 1 to 10 g of acylated carbon nanotubes obtained in step (b) and 1 to 50 g of polyhydric alcohols or polyamines into the flask, seal it, pump and fill the flask with nitrogen repeatedly three times, and process it with 40 to 100 kHz ultrasonic waves for 10 to 50 g. After 1000 minutes, react at 20-200°C for 1-20 hours, filter with suction, wash repeatedly, and dry in vacuum at 80-180°C to obtain carbon nanotubes with hydroxyl or amine groups on the surface; Step (d): Add 1 to 10 g of carbon nanotubes with hydroxyl or amino groups on the surface obtained in step (c) and 1 to 50 g of α-haloacyl halides in the flask, seal it, and repeatedly pump nitrogen for three times, with 40 to 40 g After 100kHz ultrasonic treatment for 10-1000min, react at 20-200°C for 1-20hr, suction filter, wash, and vacuum-dry at 80-180°C to obtain carbon nanotubes with initiating groups on the surface; Step (e): Add 0.6 to 5 g of catalyst and 0.7 to 5 g of ligand in the flask, then add 1 to 10 g of carbon nanotubes with initiating groups on the surface obtained in step (d), and 10 to 50 mL of solvent, and fill the flask with Ar or N ₂ for 1-100min, add 10-80mL of monomer containing double bonds, continue to fill with nitrogen or argon for 1-100min, react at 60-150℃ for 20-1000hr, after the viscosity increases significantly, stop the reaction, Precipitate in medium, redissolve the obtained precipitate in a solvent, suction filter, wash, and vacuum dry at 80-180°C to obtain single-stage polymer-grafted carbon nanotubes; Step (f): Add 0.4 to 5 g of catalyst and 0.48 to 5 g of ligand in the flask, then add 2 to 10 g of single-stage polymer-grafted carbon nanotubes obtained in step (e), and 10 to 50 mL of solvent, and fill the flask with Ar or N ₂ for 1-100min, add 10-80mL of another double bond-containing monomer, continue to fill with nitrogen or argon for 1-100min, react at 50-150℃ for 10-1000hr, stop the reaction after the viscosity increases significantly , precipitate in methanol, redissolve the obtained precipitate in a solvent, suction filter, wash, and vacuum dry at 80-180° C. to obtain block polymer-grafted carbon nanotubes. 2. the preparation method of the carbon nanotube of block polymer grafting according to claim 1 is characterized in that the carbon nanotube used in step (a) is catalytic pyrolysis, arc discharge, template method and laser evaporation method prepared single-walled or multi-walled carbon nanotubes. 3. the preparation method of the carbon nanotube grafted by block polymer according to claim 1 is characterized in that the strong oxidative acid used in step (a) comprises 60～70% nitric acid, sulfuric acid, 1/100～100/ 1 ratio nitric acid/sulfuric acid mixed acid. 4. the preparation method of the carbon nanotube of block polymer grafting according to claim 1 is characterized in that used acylating agent comprises phosphorus trichloride, phosphorus pentachloride, thionyl chloride, Phosphorus tribromide, phosphorus pentabromide or thionyl bromide. 5. the preparation method of the carbon nanotube of block polymer grafting according to claim 1 is characterized in that the polyalcohols used in step (c) or polyamines material comprise ethylene glycol, glycerol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 1,3-butanediol, butanetriol, polyethylene glycol, ethylenediamine, propane Triamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butanediamine, 1,2-butanediamine, 1,3-butanediamine, butylenetriamine or polyethylene glycol amine. 6. the preparation method of the carbon nanotube of block polymer grafting according to claim 1 is characterized in that step (c), (d) do not use solvent or use dimethyl sulfoxide, N, N- Dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, chloroform, tetrahydrofuran, ethyl acetate, acetone, acetonitrile, butanone, triethylamine, pyridine, dimethylamino Pyridine is used as a solvent or a mixed solvent containing these solvents is used as a reaction medium. 7. The preparation method of the carbon nanotube grafted by block polymer according to claim 1 is characterized in that the α-haloacyl halide used in step (d) comprises α-bromobutyryl bromide, α-bromo substituted isobutyryl bromide, α-bromopropionyl bromide, α-chlorobutyryl chloride, α-chloroisobutyryl chloride or α-chloropropionyl chloride. 8. the preparation method of the carbon nanotube of block polymer grafting according to claim 1 is characterized in that in step (e), (f), the monomer containing double bond is the monomer that can carry out radical polymerization reaction , including hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, methyl acrylate, methyl methacrylate, ammonia acrylate Ethyl ester, aminoethyl methacrylate, N,N-aminoethyl methacrylate, N,N-dimethyl-aminoethyl methacrylate, styrene, p-chloromethylstyrene, m-chloroform Styrene, acrylamide, N,N-dimethylacrylamide, methacrylamide, N,N-dimethyl-methacrylamide, N-isopropylacrylamide, N-isopropyl-methacrylamide N,N-diethylacrylamide, N,N-diethyl-methacrylamide, N,N-dihydroxyethylacrylamide, N-hydroxyethylacrylamide, N-hydroxyethylacrylamide N-(trimethylol)methacrylamide, N-(trimethylol)methacrylamide, N-aminoethylacrylamide, N-aminoethyl-methacrylamide, N-(2-dimethylamino)ethylacrylamide Amide, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, N,N-dihydroxyethylacrylamide, N -Hydroxyethylacrylamide, N-hydroxyethylmethacrylamide or N-(trimethylol)methacrylamide. 9. the preparation method of the carbon nanotube of block polymer grafting according to claim 1 is characterized in that step (e), used catalyst is to contain Cu(I), Fe(I), Mo Metal compounds of (V), Re(V), Ru(II), Ni(I), Pb(II); the ligands used are 2-bipyridine, tetramethylethylenediamine, pentamethyl-diethyl Triamine, hexamethyl-triethylenetetramine, oxalic acid, malonic acid, succinic acid, phthalic acid, triphenylphosphine or tri-n-butylphosphine; the solvents used are dimethylsulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, chloroform, dichloromethane, dichloroethane, tetrahydrofuran, ethyl acetate, acetone, butanone , acetonitrile, propanol, ethanol, methanol or mixtures containing these solvents. 10. The preparation method of the carbon nanotube grafted by block polymer according to claim 9 is characterized in that the catalyst used in step (e), (f) is cuprous chloride, cuprous bromide, chloride Ferrous, ferrous bromide, lithium molybdate, ReO ₂ I(PPh ₃ ) ₂ , RuCl ₂ , Ni(NCN)Br or Pd(OAc) ₂ . 11. The carbon nanotubes grafted by block polymers, characterized in that the carbon nanotubes grafted by block polymers obtained by the preparation method as follows: Step (a): Add 1 to 10 g of dry carbon nanotube raw material and 5 to 50 mL of strong oxidizing acid in a flask, ultrasonically treat at 40 to 100 kHz for 30 min to 100 hr, then heat to 20 to 200 ° C, stir and reflux for 0.5 ~100hr, filter with filter membrane, wash repeatedly until neutral, vacuum dry at 80~180℃ for 10~30hr to obtain acidified carbon nanotubes; Step (b): Add 1-10 g of acidified carbon nanotubes obtained in step (a) and 1-100 g of acylating agent into a flask, and after ultrasonic treatment at 40-100 kHz for 10-1000 min, heat to 20-200 ° C, stir and reflux React for 0.5-100 hours, filter with suction and wash repeatedly to remove the acylating agent, and obtain acylated carbon nanotubes; Step (c): Add 1 to 10 g of acylated carbon nanotubes obtained in step (b) and 1 to 50 g of polyhydric alcohols or polyamines into the flask, seal it, pump and fill the flask with nitrogen repeatedly three times, and process it with 40 to 100 kHz ultrasonic waves for 10 to 50 g. After 1000 minutes, react at 20-200°C for 1-20 hours, filter with suction, wash repeatedly, and dry in vacuum at 80-180°C to obtain carbon nanotubes with hydroxyl or amine groups on the surface; Step (d): Add 1 to 10 g of carbon nanotubes with hydroxyl or amino groups on the surface obtained in step (c) and 1 to 50 g of α-haloacyl halides in the flask, seal it, and repeatedly pump nitrogen for three times, with 40 to 40 g After 100kHz ultrasonic treatment for 10-1000min, react at 20-200°C for 1-20hr, suction filter, wash, and vacuum-dry at 80-180°C to obtain carbon nanotubes with initiating groups on the surface; Step (e): Add 0.6 to 5 g of catalyst and 0.7 to 5 g of ligand in the flask, then add 1 to 10 g of carbon nanotubes with initiating groups on the surface obtained in step (d), and 10 to 50 mL of solvent, and fill the flask with Ar or N ₂ for 1-100min, add 10-80mL of monomer containing double bonds, continue to fill with nitrogen or argon for 1-100min, react at 60-150℃ for 20-1000hr, after the viscosity increases significantly, stop the reaction, Precipitate in medium, redissolve the obtained precipitate in a solvent, suction filter, wash, and vacuum dry at 80-180°C to obtain single-stage polymer-grafted carbon nanotubes; Step (f): Add 0.4 to 5 g of catalyst and 0.48 to 5 g of ligand in the flask, then add 2 to 10 g of single-stage polymer-grafted carbon nanotubes obtained in step (e), and 10 to 50 mL of solvent, and fill the flask with Ar or N ₂ for 1-100min, add 10-80mL of another double bond-containing monomer, continue to fill with nitrogen or argon for 1-100min, react at 50-150℃ for 10-1000hr, stop the reaction after the viscosity increases significantly , precipitate in methanol, redissolve the obtained precipitate in a solvent, suction filter, wash, and vacuum dry at 80-180° C. to obtain block polymer-grafted carbon nanotubes.

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