A preparation method of functionalized carbon black

Abstract

The present invention discloses a preparation method of functionalized carbon black, which relates to the technical field of carbon black modification and specifically includes: treating carbon black with an oxidant solution to obtain pre-activated carbon black; placing the pre-activated carbon black in a first dispersant solution for treatment to obtain primary modified carbon black; the first dispersant solution is a mixed solution of sodium carboxymethyl cellulose, sodium dodecyl sulfate, and Triton-100; placing the primary modified carbon black in a second dispersant solution for treatment to obtain secondary modified carbon black; the second dispersant solution is a mixed solution of a polycarboxylic acid-based dispersant and polyvinylpyrrolidone, and placing the secondary modified carbon black in a reaction solution of an organic polymer monomer and polyethyleneimine for treatment to obtain functionalized carbon black. By pre-activating the carbon black and then performing multiple coating modifications on the pre-activated carbon black, the prepared functionalized carbon black not only has good dispersibility, but also can well improve the properties of the material when added to a rubber matrix.

Description

Technical Field

[0001] The invention relates to the technical field of carbon black modification, and in particular to a method for preparing functionalized carbon black. Background Art

[0002] Carbon black is a nano-scale carbon material generated by incomplete combustion or thermal decomposition of hydrocarbons. Its main component is carbon and it has the characteristics of high specific surface area, conductivity, adsorption and reinforcement. Carbon black was mainly used for rubber reinforcement (such as tire manufacturing) in the early days due to its high tinting power, low cost and wear resistance, accounting for more than 90% of the global carbon black consumption. With the development of emerging fields such as new energy, semiconductors, and conductive materials, the functional demand for carbon black has increased significantly.

[0003] Carbon black is essentially nano-scale carbon particles, which have the following disadvantages in the application process: 1. Carbon black particles have high surface energy and are easy to form agglomerates through van der Waals forces, which makes it difficult to disperse, especially in polar or non-polar solvents, affecting its uniform distribution in composite materials; 2. The content of active functional groups on the surface of carbon black is low, and its affinity with the solvent or matrix is ​​weak, resulting in poor wettability; 3. The chemical activity of the unmodified carbon black surface is low, and it is difficult to load functional groups (such as nitrogen doping, metal oxide modification), which limits its application. Therefore, in order to improve the application of carbon black, carbon black needs to be modified. Traditional carbon black modification methods include grinding modification, dispersant modification, and polymer coating modification. The above single methods are not effective when used to treat carbon black, and the selection of dispersants, monomers during polymer coating, and other conditions will also affect the functionality and dispersibility of carbon black. Therefore, it is of great significance to provide functional carbon black with good dispersibility. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the shortcomings of the prior art, a method for preparing functionalized carbon black is provided. The method pre-activates the carbon black and then performs multiple coating modifications on the pre-activated carbon black. The obtained functionalized carbon black not only has good dispersibility, but also can greatly improve the performance of the material when added to the rubber matrix.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for preparing functionalized carbon black comprises the following steps:

[0007] Treating carbon black with an oxidant solution to obtain preactivated carbon black;

[0008] The preactivated carbon black is placed in a first dispersant solution for treatment, and the first dispersant forms a first coating layer on the surface of the preactivated carbon black to obtain a primary modified carbon black; the first dispersant solution is a mixed solution of sodium carboxymethyl cellulose, sodium dodecyl sulfate, and Triton-100;

[0009] The primary modified carbon black is placed in a second dispersant solution for treatment, and the second dispersant forms a second coating layer on the surface of the primary modified carbon black to obtain a secondary modified carbon black; the second dispersant solution is a mixed solution of a polycarboxylic acid dispersant and polyvinyl pyrrolidone, and the mass ratio of the polycarboxylic acid dispersant to the polyvinyl pyrrolidone is (1-3):1;

[0010] The secondary modified carbon black is placed in a reaction solution of an organic polymer monomer and polyethyleneimine, and the organic polymer monomer is polymerized in situ on the surface of the secondary modified carbon black to form a third coating layer to obtain functionalized carbon black; the organic polymer monomer is a mixture of choline chloride, acrylic acid, maleic anhydride, and polypropylene glycol diacrylate.

[0011] Preferably, the oxidant solution is a hydrogen peroxide solution, and the concentration of the hydrogen peroxide solution is 30-50wt%; when the carbon black is treated with the hydrogen peroxide solution, the pH of the reaction system is 3-5, and the treatment is carried out under light-proof conditions, 100-500rpm, and 25-40°C for 6-20h.

[0012] The present invention uses a hydrogen peroxide solution to pre-activate carbon black, thereby introducing oxygen-containing functional groups, such as carboxyl groups or hydroxyl groups, on the surface of the carbon black to increase its hydrophilicity and provide active sites for subsequent modification.

[0013] Preferably, in the first dispersant solution, the mass ratio of sodium carboxymethyl cellulose, sodium dodecyl sulfate and Triton-100 is 1: (0.2-0.7): (0.1-0.4); the total weight of the first dispersant is 5-10wt% of the weight of the pre-activated carbon black.

[0014] Preferably, when the pre-activated carbon black is treated with the first dispersant solution, the pH of the treatment system is 8.0-9.0. First, the pre-dispersion treatment is carried out at a stirring speed of 200-400 rpm for 10-13 minutes, then the stirring speed is increased to 1000-2000 rpm, and stirred again for 10-20 minutes, and finally assisted ultrasonic treatment is carried out at an ultrasonic power of 200-300 W for 17-20 minutes.

[0015] The present invention adopts sodium carboxymethyl cellulose, sodium dodecyl sulfate and Triton-100 as the first dispersant. Sodium carboxymethyl cellulose is used as a high molecular polymer to stabilize the dispersion system mainly through the steric hindrance effect, forming a thick adsorption layer to prevent particle agglomeration; sodium dodecyl sulfate is used as an anionic surfactant to reduce the attraction between particles through electrostatic repulsion and reduce the surface tension at the same time; Triton-100 stabilizes the particles through hydrophobic interaction and steric hindrance. When the three are combined, they play multiple roles of electrostatic repulsion, steric hindrance and hydrophobic stability at the same time, forming a more comprehensive protective layer, and realizing the initial coating modification of carbon black.

[0016] Preferably, the process of treating the primary modified carbon black in the second dispersant solution comprises the following steps:

[0017] The first monomer, chain transfer agent and ethanol solution are mixed to obtain solution A, the second monomer, initiator and ethanol solution are mixed to obtain solution B, solution A is heated, and solution B is added dropwise to solution A to react at the same temperature, after the reaction is completed, the solvent is removed and unreacted monomers are removed by dialysis, and the product is freeze-dried to obtain a prepolymer;

[0018] A prepolymer, a chain transfer agent, and an ethanol solution are mixed to obtain a solution C; a third monomer, an initiator, and an ethanol solution are mixed to obtain a solution D; the solution C is heated, and the solution D is added dropwise to the solution C to react at the same temperature; after the reaction is completed, the solvent in the system is removed, the pH of the system is adjusted to be neutral, and the product is freeze-dried to obtain a polycarboxylic acid dispersant;

[0019] A polycarboxylic acid dispersant and polyvinyl pyrrolidone are added to ethanol and stirred to obtain a second dispersant solution. The primary modified carbon black is added to the second dispersant solution, ultrasonically dispersed, then centrifuged, precipitated and dried to obtain a secondary modified carbon black.

[0020] The present invention adopts a variety of monomers and effectively regulates the polymer chain structure through step-by-step free radical polymerization to form a block / graft copolymer with both hydrophilicity and hydrophobicity; polyethylene glycol methyl ether methacrylate provides hydrophilicity and flexible segments, improves the water solubility and steric hindrance effect of the dispersant; phenoxyethyl methacrylate and benzyl methacrylate introduce hydrophobic aromatic rings, and strongly anchor the carbon black surface through the π-π effect to improve the adsorption stability; and 2-acrylamide-2-methylpropane sulfonic acid gives sulfonic acid groups, enhances electrostatic repulsion, and prevents particle agglomeration. The polycarboxylic acid dispersant obtained by the polymerization of the above monomers is compounded with polyvinyl pyrrolidone as the second dispersant. The polycarboxylic acid dispersant contains sulfonic acid groups, polyether segments and aromatic groups at the same time, and can be anchored at multiple points for different active sites on the carbon black surface. Through multiple effects such as anchoring, electrostatic repulsion, and long-chain steric hindrance, the interfacial bonding strength is enhanced, and at the same time, the physical adsorption of polyvinyl pyrrolidone is used to form a double coating structure to improve the dispersion stability of carbon black.

[0021] Preferably, the temperature of solution A and solution C is raised to 70-80° C., and before the temperature of solution A and solution C is raised, the process further comprises the step of introducing nitrogen into solution A and solution C to replace the air.

[0022] Preferably, the first monomer is polyethylene glycol methyl ether methacrylate, the second monomer is 2-acrylamido-2-methylpropanesulfonic acid, and the third monomer is a mixture of phenoxyethyl methacrylate and benzyl methacrylate, and the mass ratio of the two is 1:(1-2); the chain transfer agent is thioglycolic acid, and the initiator is ammonium persulfate; the volume ratio of ethanol to deionized water in the ethanol solution is 1:(1-2).

[0023] Preferably, in solution A, the concentrations of polyethylene glycol methyl ether methacrylate and thioglycolic acid are 0.1-0.12 g / ml and 0.00005-0.000053 g / ml, respectively; in solution B, the concentrations of 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate are 0.5-0.53 g / ml and 0.004-0.005 g / ml, respectively; in solution C, the concentrations of prepolymer and chain transfer agent are 0.12-0.14 g / ml and 0.000032-0.000036 g / ml, respectively; in solution D, the concentrations of phenoxyethyl methacrylate and ammonium persulfate are 0.1-0.11 g / ml and 0.0032-0.0037 g / ml, respectively; the volume ratio of solution A to solution B is 6:(1-2); the volume ratio of solution C to solution D is 6:(1-2).

[0024] Preferably, the reaction process is specifically as follows: choline chloride, acrylic acid, and maleic anhydride are heated and stirred until clear and transparent, then polyethyleneimine is added in batches, stirring is continued until the solution is clear and transparent, polypropylene glycol diacrylate and photoinitiator-2959 are added, and the mixture is stirred to obtain a mixed solution, the above-mentioned secondary modified carbon black is added and stirred evenly, and then placed under an ultraviolet light source for irradiation reaction, filtered after the reaction is completed, the precipitate is washed with ethanol, and freeze-dried to obtain functionalized carbon black.

[0025] The present invention first uses choline chloride to form a deep eutectic solvent with acrylic acid and maleic anhydride to replace traditional organic solvents. It has low toxicity and biodegradable characteristics, which is in line with the concept of green chemistry. During the cross-linking reaction, polyethyleneimine is added to the reaction system in batches. The agglomeration or uneven cross-linking caused by excessive local concentration of polyethyleneimine is avoided by the dripping time and dripping interval of each batch of polyethyleneimine, thereby improving the uniformity of the reaction; polypropylene glycol diacrylate is used as a cross-linking agent, and its long chain structure can further wrap the carbon black particles to form a core-shell structure, thereby enhancing the dispersion stability of carbon black. In addition, the polar groups on the surface of the secondary modified carbon black of the present invention can form stronger hydrogen bonds or chemical bonds with polyethyleneimine and acrylic acid and maleic anhydride monomers to improve interfacial compatibility; moreover, the copolymer of maleic anhydride and acrylic acid can form dynamic hydrogen bonds and coordination bonds, enhance the mechanical interlocking of carbon black and the polymer matrix, and improve the mechanical properties of the material.

[0026] Preferably, the molar ratio of choline chloride, acrylic acid, maleic anhydride, polyethyleneimine, polypropylene glycol diacrylate, and photoinitiator-2959 is 1:1:1: (0.002-0.004): (0.01-0.02): (0.01-0.02).

[0027] Preferably, polyethyleneimine is added in 3-4 batches, with the interval between each batch addition being 5-10 minutes.

[0028] Preferably, the amount of the secondary modified carbon black added is 15-20% of the mass of the mixed liquid.

[0029] Preferably, the wavelength of the light source during the irradiation reaction is 365 nm, and the irradiation time is 1-5 min.

[0030] Due to the adoption of the above technical solution, the present invention has at least the following beneficial effects:

[0031] 1. In order to improve the dispersibility of carbon black, the present invention first performs surface activation treatment on carbon black, and then performs multi-stage coating modification to form different functional coatings on the surface of carbon black, so that the obtained carbon black has good dispersibility. Specifically, the surface of carbon black is first activated by a hydrogen peroxide solution, and oxygen-containing functional groups such as carboxyl and hydroxyl groups are introduced on the surface of carbon black to provide active sites for subsequent modification. When the activated carbon black is initially dispersed, a composite system consisting of sodium carboxymethyl cellulose, sodium dodecyl sulfate and Triton-100 is used for modification. The above three dispersants form a coating layer through physical adsorption and chemical bonding, which reduces the van der Waals force between carbon black particles and improves the dispersibility of carbon black. In order to further improve the dispersibility of carbon black, the present invention uses a self-made polycarboxylic acid dispersant and polyvinyl pyrrolidone to treat the primary modified carbon black again. The polycarboxylic acid dispersant contains sulfonic acid groups, carboxylic acid groups, and polyethylene glycol chains, which can be adsorbed on the surface of carbon black through multi-point anchoring, and the long polymer chain provides strong steric hindrance. Polyvinyl pyrrolidone adsorbs the carbon black surface through π-π conjugation to form a dynamic hydrogen bond network, which enhances the dispersion stability. Finally, the present invention uses choline chloride, acrylic acid, and maleic anhydride to form a hydrogen bond cross-linking network, polyethylene imine provides amino cross-linking points, and polypropylene glycol diacrylate enhances flexibility; the above polymer layer forms a shell layer on the surface of the secondary modified carbon black through covalent cross-linking, forming a three-dimensional network structure, enhancing the interface bonding force, and improving the dispersibility of carbon black.

[0032] 2. The functionalized carbon black of the present invention has good performance and can be added to the rubber matrix to improve the performance of the rubber material. The functionalized carbon black uses carbon black as a rigid core to provide high-strength support, and the outermost polymer coating absorbs impact energy through deformation to form an energy-consuming structure similar to a "sandbag", thereby improving the performance of the material. Moreover, the sulfonic acid group and carboxylic acid group in the polycarboxylic acid dispersant in the second dispersant coating form multi-point anchoring with the polar groups on the surface of carbon black, and at the same time, the polyethylene glycol chain is entangled with the rubber matrix through van der Waals force to form a "rigid and flexible" interface transition layer. The benzene rings in the phenoxyethyl methacrylate and benzyl methacrylate in the second dispersant coating strongly adsorb with the graphitized area on the surface of carbon black through π-π conjugation to form physical anchoring points and reduce interface slip; the hydrophobic segment of benzyl methacrylate matches the compatibility of the rubber matrix, dissipates energy through molecular chain slip and rearrangement during the stretching process, delays crack propagation, and improves the performance of the rubber material. In addition, the hydrogen bond network formed by choline chloride, acrylic acid and maleic anhydride in the polymer coating can be dynamically broken and reorganized, and absorbs energy through reversible bond breaking when subjected to external force, thereby improving tensile strength and toughness. Sodium carboxymethyl cellulose in the first dispersant bonds with the surface of carbon black through hydroxyl groups, and its long chain structure forms physical entanglement, combined with the electrostatic repulsion of sodium dodecyl sulfate and the steric hindrance of Triton-100, to achieve nano-scale dispersion of carbon black in the rubber matrix, reduce stress concentration points, and improve the performance of rubber materials. DETAILED DESCRIPTION

[0033] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0035] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention. Example 1

[0036] A method for preparing functionalized carbon black comprises the following steps:

[0037] S1: Disperse carbon black N330 in a 30wt% hydrogen peroxide solution, adjust the pH of the system to 4, and activate the mixture for 15h at 200rpm and 40°C in a dark environment to obtain pre-activated carbon black;

[0038] S2: Add 1g sodium carboxymethyl cellulose (average relative molecular mass 250000, degree of substitution 1.2), 0.3g sodium dodecyl sulfate, and 0.2g Triton-100 to 80ml ethanol solution (volume ratio of ethanol to deionized water is 1:8), stir and mix at 500rpm for 30min, then add the above-mentioned preactivated carbon black (the addition amount is 11 times the total weight of sodium carboxymethyl cellulose, sodium dodecyl sulfate, and Triton-100), adjust the pH of the system to 8.0, first pre-disperse at a stirring speed of 200rpm for 10min, then increase the stirring speed to 1000rpm, stir again for 10min, and finally assist ultrasonic treatment at an ultrasonic power of 300W for 17min; then filter, precipitate and dry to obtain a primary modified carbon black;

[0039] S3: Polyethylene glycol methyl ether methacrylate (Mn=300), thioglycolic acid, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution A (in solution A, the concentrations of polyethylene glycol methyl ether methacrylate and thioglycolic acid are 0.11 g / ml and 0.000051 g / ml, respectively), and 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution B (in solution B, 2-acrylamido-2-methylpropanesulfonic acid , and ammonium persulfate concentrations are 0.52 g / ml and 0.004 g / ml, respectively), solution A is heated to 74°C, nitrogen is introduced into solution A to replace the air, and then solution B is added dropwise to solution A (the volume ratio of solution A to solution B is 6:1), the dropping time of solution B is 30 min, and the reaction is kept warm for 2 h under nitrogen atmosphere. After the reaction is completed, the reaction is stopped in an ice water bath, and the solvent is removed and dialyzed for 3 days to remove unreacted monomers (the molecular weight cutoff of the dialysis bag is 3000 Da), and the product is freeze-dried to obtain a prepolymer;

[0040] S4: prepolymer, thioglycolic acid, ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution C (in solution C, the concentrations of prepolymer and thioglycolic acid are 0.125 g / ml and 0.000033 g / ml, respectively), the third monomer (a mixture of phenoxyethyl methacrylate and benzyl methacrylate, the mass ratio of the two is 1:1), ammonium persulfate, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution D (in solution D, the concentrations of phenoxyethyl methacrylate and ammonium persulfate are 0.11 g / ml and 0.0033 g / ml, respectively), solution C is heated to 74°C, and solution D is added dropwise to solution C (the volume ratio of solution C to solution D is 6:1), the reaction is kept warm for 4 hours, the reaction is terminated in an ice water bath after the reaction is completed, and then the solvent in the system is removed by rotary evaporation, the pH of the system is adjusted to neutral, and the product is freeze-dried to obtain a polycarboxylic acid dispersant;

[0041] S5: 2g of the above-mentioned polycarboxylic acid dispersant and 1g of polyvinyl pyrrolidone (average molecular weight of 1300000) were added to 100ml of ethanol, and stirred at 600rpm for 30min to obtain a second dispersant solution, and primary modified carbon black (the addition amount was 5 times the total weight of the polycarboxylic acid dispersant and polyvinyl pyrrolidone) was added to the second dispersant solution, and ultrasonic dispersion was carried out at a power of 500W for 40min, and then filtered, precipitated and dried to obtain secondary modified carbon black;

[0042] S6: Heat choline chloride, acrylic acid, and maleic anhydride to 80°C and stir until the solution is clear and transparent, then add polyethyleneimine in three batches, with a drop interval of 5 minutes for each batch, and a drop time of 6 minutes for each batch of polyethyleneimine. After the drop addition of polyethyleneimine is completed, continue to stir at 80°C for 30 minutes until the solution is clear and transparent, then add polypropylene glycol diacrylate and photoinitiator-2959, continue to stir and mix at 80°C for 10 minutes, and obtain a mixed solution (choline chloride, acrylic acid, maleic anhydride, polyethyleneimine (molecular weight 1800), The molar ratio of polypropylene glycol diacrylate (Mn=700) and photoinitiator-2959 is 1:1:1:0.002:0.01:0.01), and the secondary modified carbon black (the addition amount is 15% of the mass of the mixed liquid) is added to the mixed liquid, and the mixture is stirred for 3 hours at 80°C and 500rpm in a nitrogen atmosphere. The reaction liquid is placed under an ultraviolet light source with a light source band of 365nm and irradiated for 2 minutes. After the reaction, the reaction liquid is centrifuged at 8000rpm for 15 minutes, and the precipitate is washed and then vacuum dried at 60°C to obtain functionalized carbon black. Example 2

[0043] A method for preparing functionalized carbon black comprises the following steps:

[0044] S1: Disperse carbon black N330 in a 30wt% hydrogen peroxide solution, adjust the pH of the system to 4, and activate the mixture for 15h at 200rpm and 40°C in a dark environment to obtain pre-activated carbon black;

[0045] S2: Add 1g sodium carboxymethyl cellulose (average relative molecular mass 250000, degree of substitution 1.2), 0.5g sodium dodecyl sulfate, and 0.2g Triton-100 to 80ml ethanol solution (volume ratio of ethanol to deionized water is 1:8), stir and mix at 500rpm for 30min, then add the above-mentioned preactivated carbon black (the addition amount is 16 times the total weight of sodium carboxymethyl cellulose, sodium dodecyl sulfate, and Triton-100), adjust the pH of the system to 8.0, first pre-disperse at a stirring speed of 300rpm for 12min, then increase the stirring speed to 1500rpm, stir again for 12min, and finally assist ultrasonic treatment at an ultrasonic power of 300W for 18min; then filter, precipitate and dry to obtain a primary modified carbon black;

[0046] S3: Polyethylene glycol methyl ether methacrylate (Mn=300), thioglycolic acid, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution A (in solution A, the concentrations of polyethylene glycol methyl ether methacrylate and thioglycolic acid are 0.12 g / ml and 0.000052 g / ml, respectively), and 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution B (in solution B, 2-acrylamido-2-methylpropanesulfonic acid, The concentrations of ammonium persulfate were 0.52 g / ml and 0.0043 g / ml, respectively. Solution A was heated to 74°C, nitrogen was introduced into solution A to replace the air, and then solution B was added dropwise to solution A (the volume ratio of solution A to solution B was 6:1). The dropping time of solution B was 30 min, and the reaction was kept warm for 2 h under nitrogen atmosphere. After the reaction was completed, the reaction was stopped in an ice water bath, and the solvent was removed and dialyzed for 3 days to remove the unreacted monomers (the molecular weight cut-off of the dialysis bag was 3000 Da). The product was freeze-dried to obtain a prepolymer.

[0047] S4: prepolymer, thioglycolic acid, ethanol solution (ethanol, deionized water volume ratio of 1:1) were mixed to obtain solution C (in solution C, the concentration of prepolymer and thioglycolic acid were 0.13g / ml, 0.000034g / ml, respectively), the third monomer (a mixture of phenoxyethyl methacrylate and benzyl methacrylate, the mass ratio of the two was 1:1), ammonium persulfate and ethanol solution (ethanol and deionized water volume ratio of 1:1) were mixed to obtain solution D (in solution D, the concentration of phenoxyethyl methacrylate and ammonium persulfate were 0.1g / ml, 0.0033g / ml, respectively), solution C was heated to 74°C, and solution D was added dropwise to solution C (solution C, solution D volume ratio of 6:1), the reaction was kept warm for 5h, after the reaction was completed, the reaction was terminated in an ice water bath, and then the solvent in the system was removed by rotary evaporation, the pH of the system was adjusted to neutral, and the product was freeze-dried to obtain a polycarboxylic acid dispersant;

[0048] S5: 3 g of the above-mentioned polycarboxylic acid dispersant and 1 g of polyvinyl pyrrolidone (average molecular weight of 1,300,000) were added to 100 ml of ethanol, and stirred at 700 rpm for 30 min to obtain a second dispersant solution, and primary modified carbon black (the addition amount was 5 times the total weight of the polycarboxylic acid dispersant and polyvinyl pyrrolidone) was added to the second dispersant solution, and ultrasonic dispersion was performed at a power of 500 W for 60 min, and then filtered, precipitated and dried to obtain secondary modified carbon black;

[0049] S6: Heat choline chloride, acrylic acid, and maleic anhydride to 80°C and stir until the solution is clear and transparent. Then add polyethyleneimine in three batches, with a drop interval of 10 minutes for each batch, and a drop time of 7 minutes for each batch of polyethyleneimine. After the drop addition of polyethyleneimine is completed, continue to stir at 80°C for 30 minutes until the solution is clear and transparent. Then add polypropylene glycol diacrylate and photoinitiator-2959. Continue to stir and mix at 80°C for 10 minutes to obtain a mixed solution (choline chloride, acrylic acid, maleic anhydride, polyethyleneimine (molecular weight 1800), polypropylene glycol diacrylate, and photoinitiator-2959). The molar ratio of diol diacrylate (Mn=700) and photoinitiator-2959 is 1:1:1:0.003:0.01:0.02), and the secondary modified carbon black (the addition amount is 16% of the mass of the mixed liquid) is added to the mixed liquid, and the mixture is stirred for 3 hours at 80°C and 500rpm in a nitrogen atmosphere. The reaction liquid is placed under an ultraviolet light source with a light source band of 365nm and irradiated for 1.5 minutes. After the reaction, the reaction liquid is centrifuged at 8000rpm for 20 minutes, and the precipitate is washed and then vacuum dried at 60°C to obtain functionalized carbon black. Example 3

[0050] A method for preparing functionalized carbon black comprises the following steps:

[0051] S1: Disperse carbon black N330 in a 30wt% hydrogen peroxide solution, adjust the pH of the system to 4, and activate the mixture for 15h at 200rpm and 40°C in a dark environment to obtain pre-activated carbon black;

[0052] S2: Add 1g sodium carboxymethyl cellulose (average relative molecular mass 250000, degree of substitution 1.2), 0.6g sodium dodecyl sulfate, and 0.3g Triton-100 to 80ml ethanol solution (volume ratio of ethanol to deionized water is 1:8), stir and mix at 500rpm for 30min, then add the above-mentioned preactivated carbon black (the addition amount is 18 times the total weight of sodium carboxymethyl cellulose, sodium dodecyl sulfate, and Triton-100), adjust the pH of the system to 8.0, first pre-disperse at a stirring speed of 300rpm for 12min, then increase the stirring speed to 2000rpm, stir again for 20min, and finally assist ultrasonic treatment at an ultrasonic power of 200W for 17min; then filter, precipitate and dry to obtain a primary modified carbon black;

[0053] S3: Polyethylene glycol methyl ether methacrylate (Mn=300), thioglycolic acid, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution A (in solution A, the concentrations of polyethylene glycol methyl ether methacrylate and thioglycolic acid are 0.1 g / ml and 0.000052 g / ml, respectively), and 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution B (in solution B, 2-acrylamido-2-methylpropanesulfonic acid, The concentrations of ammonium persulfate were 0.5 g / ml and 0.0045 g / ml, respectively. Solution A was heated to 74°C, nitrogen was introduced into solution A to replace the air, and then solution B was added dropwise to solution A (the volume ratio of solution A to solution B was 6:1). The dropping time of solution B was 30 min, and the reaction was kept warm for 2 h under nitrogen atmosphere. After the reaction was completed, the reaction was stopped in an ice water bath, and the solvent was removed and dialyzed for 3 days to remove the unreacted monomers (the molecular weight cut-off of the dialysis bag was 3000 Da). The product was freeze-dried to obtain a prepolymer.

[0054] S4: prepolymer, thioglycolic acid, ethanol solution (ethanol, deionized water volume ratio is 1:1) are mixed to obtain solution C (in solution C, the concentration of prepolymer and thioglycolic acid are 0.13g / ml and 0.000035g / ml, respectively), the third monomer (a mixture of phenoxyethyl methacrylate and benzyl methacrylate, the mass ratio of the two is 1:1), ammonium persulfate and ethanol solution (ethanol and deionized water volume ratio is 1:1) are mixed to obtain solution D (in solution D, the concentration of phenoxyethyl methacrylate and ammonium persulfate are 0.11g / ml and 0.0033g / ml, respectively), solution C is heated to 74°C, and solution D is added dropwise to solution C (the volume ratio of solution C to solution D is 6:1), the reaction is kept warm for 4h, after the reaction is completed, the reaction is terminated in an ice water bath, and then the solvent in the system is removed by rotary evaporation, the pH of the system is adjusted to neutral, and the product is freeze-dried to obtain a polycarboxylic acid dispersant;

[0055] S5: 3 g of the above-mentioned polycarboxylic acid dispersant and 1 g of polyvinyl pyrrolidone (average molecular weight of 1,300,000) were added to 100 ml of ethanol, and stirred at 800 rpm for 30 min to obtain a second dispersant solution, and primary modified carbon black (the addition amount was 8 times the total weight of the polycarboxylic acid dispersant and polyvinyl pyrrolidone) was added to the second dispersant solution, and ultrasonic dispersion was performed at a power of 500 W for 60 min, and then filtered, precipitated and dried to obtain secondary modified carbon black;

[0056] S6: Heat choline chloride, acrylic acid, and maleic anhydride to 80°C and stir until clear and transparent, then add polyethyleneimine in 3 batches, with an interval of 8 minutes between each batch of additions, and a dropping time of 7 minutes for each batch of polyethyleneimine. After the addition of polyethyleneimine is completed, continue stirring at 80°C for 30 minutes until the solution is clear and transparent, then add polypropylene glycol diacrylate and photoinitiator-2959, continue stirring and mixing at 80°C for 10 minutes, and obtain a mixed solution (choline chloride, acrylic acid, maleic anhydride, polyethyleneimine (molecular weight 1800), polypropylene glycol diacrylate, and photoinitiator-2959). The molar ratio of propylene glycol diacrylate (Mn=700) and photoinitiator-2959 is 1:1:1:0.003:0.02:0.02), and the secondary modified carbon black (the addition amount is 18% of the mass of the mixed liquid) is added to the mixed liquid, and the mixture is stirred for 3 hours at 80°C and 500rpm in a nitrogen atmosphere. The reaction liquid is placed under an ultraviolet light source with a light source band of 365nm and irradiated for 2 minutes. After the reaction, the reaction liquid is centrifuged at 8000rpm for 20 minutes, and the precipitate is washed and then vacuum dried at 60°C to obtain functionalized carbon black. Example 4

[0057] A method for preparing functionalized carbon black comprises the following steps:

[0058] S1: Disperse carbon black N330 in a 30wt% hydrogen peroxide solution, adjust the pH of the system to 4, and activate the mixture for 15h at 200rpm and 40°C in a dark environment to obtain pre-activated carbon black;

[0059] S2: Add 1g sodium carboxymethyl cellulose (average relative molecular mass 250000, degree of substitution 1.2), 0.7g sodium dodecyl sulfate, and 0.4g Triton-100 to 80ml ethanol solution (volume ratio of ethanol to deionized water is 1:8), stir and mix at 500rpm for 30min, then add the above-mentioned preactivated carbon black (the addition amount is 20 times the total weight of sodium carboxymethyl cellulose, sodium dodecyl sulfate, and Triton-100), adjust the pH of the system to 8.0, first pre-disperse at a stirring speed of 400rpm for 13min, then increase the stirring speed to 2000rpm, stir again for 20min, and finally assist ultrasonic treatment at an ultrasonic power of 300W for 20min; then filter, precipitate and dry to obtain a primary modified carbon black;

[0060] S3: Polyethylene glycol methyl ether methacrylate (Mn=300), thioglycolic acid, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution A (in solution A, the concentrations of polyethylene glycol methyl ether methacrylate and thioglycolic acid are 0.12 g / ml and 0.000053 g / ml, respectively), and 2-acrylamido-2-methylpropanesulfonic acid, ammonium persulfate, and ethanol solution (the volume ratio of ethanol to deionized water is 1:1) are mixed to obtain solution B (in solution B, 2-acrylamido-2-methylpropanesulfonic acid , and ammonium persulfate concentrations are 0.53 g / ml and 0.005 g / ml, respectively), solution A is heated to 74°C, nitrogen is introduced into solution A to replace the air, and then solution B is added dropwise to solution A (the volume ratio of solution A to solution B is 6:1), the dropping time of solution B is 30 min, and the reaction is kept warm for 2 h under nitrogen atmosphere. After the reaction is completed, the reaction is stopped in an ice water bath, and the solvent is removed and dialyzed for 3 days to remove unreacted monomers (the molecular weight cutoff of the dialysis bag is 3000 Da), and the product is freeze-dried to obtain a prepolymer;

[0061] S4: prepolymer, thioglycolic acid, ethanol solution (ethanol, deionized water volume ratio is 1:1) are mixed to obtain solution C (in solution C, the concentration of prepolymer and thioglycolic acid are 0.14g / ml and 0.000036g / ml, respectively), the third monomer (a mixture of phenoxyethyl methacrylate and benzyl methacrylate, the mass ratio of the two is 1:1), ammonium persulfate and ethanol solution (ethanol and deionized water volume ratio is 1:1) are mixed to obtain solution D (in solution D, the concentration of phenoxyethyl methacrylate and ammonium persulfate are 0.11g / ml and 0.0037g / ml, respectively), solution C is heated to 74°C, and solution D is added dropwise to solution C (the volume ratio of solution C to solution D is 6:1), the reaction is kept warm for 5h, after the reaction is completed, the reaction is terminated in an ice water bath, and then the solvent in the system is removed by rotary evaporation, the pH of the system is adjusted to neutral, and the product is freeze-dried to obtain a polycarboxylic acid dispersant;

[0062] S5: 3 g of the above-mentioned polycarboxylic acid dispersant and 1 g of polyvinyl pyrrolidone (average molecular weight of 1,300,000) were added to 100 ml of ethanol, and stirred at 800 rpm for 30 min to obtain a second dispersant solution, and primary modified carbon black (the addition amount was 10 times the total weight of the polycarboxylic acid dispersant and polyvinyl pyrrolidone) was added to the second dispersant solution, and ultrasonic dispersion was performed at a power of 500 W for 60 min, and then filtered, precipitated and dried to obtain secondary modified carbon black;

[0063] S6: Heat choline chloride, acrylic acid, and maleic anhydride to 80°C and stir until clear and transparent, then add polyethyleneimine in three batches, with an interval of 10 minutes between each batch of drops, and a dropping time of 8 minutes for each batch of polyethyleneimine. After the addition of polyethyleneimine is completed, continue stirring at 80°C for 30 minutes until the solution is clear and transparent, then add polypropylene glycol diacrylate and photoinitiator-2959, continue stirring and mixing at 80°C for 10 minutes, and obtain a mixed solution (choline chloride, acrylic acid, maleic anhydride, polyethyleneimine (molecular weight 1800), polypropylene glycol diacrylate, and photoinitiator-2959). The molar ratio of propylene glycol diacrylate (Mn=700) and photoinitiator-2959 is 1:1:1:0.004:0.02:0.02), and the secondary modified carbon black (the addition amount is 20% of the mass of the mixed liquid) is added to the mixed liquid, and the mixture is stirred for 4 hours at 80°C and 500rpm in a nitrogen atmosphere. The reaction liquid is placed under an ultraviolet light source with a light source band of 365nm and irradiated for 5 minutes. After the reaction, the reaction liquid is centrifuged at 8000rpm for 20 minutes, and the precipitate is washed and then vacuum dried at 60°C to obtain functionalized carbon black.

[0064] In order to better prove that the functionalized carbon black prepared by the method of the present invention has better dispersibility and can better improve the performance of tire rubber, the following is further explained with reference to Example 3 in combination with multiple comparative examples.

[0065] Comparative Example 1

[0066] Different from Example 3, this comparative example does not include S2, and other operations are the same as Example 3.

[0067] Comparative Example 2

[0068] Different from Example 3, this comparative example does not include S3, S4, and S5, and other operations are the same as Example 3.

[0069] Comparative Example 3

[0070] Different from Example 3, this comparative example does not include S6, and other operations are the same as Example 3.

[0071] Comparative Example 4

[0072] Different from Example 3, this comparative example does not include S3, S4, S5, and S6, and other operations are the same as Example 3.

[0073] Comparative Example 5

[0074] Different from Example 3, this comparative example does not include S2 and S6, and other operations are the same as Example 3.

[0075] Comparative Example 6

[0076] Different from Example 3, this comparative example does not include S2, S3, S4, and S5, and other operations are the same as Example 3.

[0077] Comparative Example 7

[0078] Different from Example 3, in this comparative example S2, in the preparation of the first modified carbon black, the dispersant is sodium carboxymethyl cellulose, and the other operations are the same as in Example 3.

[0079] Comparative Example 8

[0080] Different from Example 3, in this comparative example S2, in the preparation of the first modified carbon black, the dispersant is sodium dodecyl sulfate, and the other operations are the same as in Example 3.

[0081] Comparative Example 9

[0082] Different from Example 3, in this comparative example S2, in the preparation of the first modified carbon black, the dispersant is Triton-100, and the other operations are the same as in Example 3.

[0083] Comparative Example 10

[0084] Different from Example 3, in this comparative example S2, in the preparation of the primary modified carbon black, the dispersant is a mixture of sodium carboxymethyl cellulose and sodium dodecyl sulfate, and the usage ratio of the two and other operations are the same as those in Example 3.

[0085] Comparative Example 11

[0086] Different from Example 3, in this comparative example S2, in the preparation of the primary modified carbon black, the dispersant is a mixture of sodium dodecyl sulfate and Triton-100, and the dosage ratio of the two and other operations are the same as those in Example 3.

[0087] Comparative Example 12

[0088] Different from Example 3, in this comparative example S2, in the preparation of the primary modified carbon black, the dispersant is a mixture of sodium carboxymethyl cellulose and Triton-100, and the dosage ratio of the two and other operations are the same as those in Example 3.

[0089] Comparative Example 13

[0090] Different from Example 3, in this comparative example S2, the amount of preactivated carbon black added is 30 times the total weight of sodium carboxymethyl cellulose, sodium lauryl sulfate, and Triton-100, and the other operations are the same as in Example 3.

[0091] Comparative Example 14

[0092] Different from Example 3, in this comparative example S3, an equal amount of acrylic acid is used to replace 2-acrylamido-2-methylpropanesulfonic acid, and other operations are the same as in Example 3.

[0093] Comparative Example 15

[0094] Different from Example 3, in this comparative example S4, the third monomer is phenoxyethyl methacrylate, and the other operations are the same as those in Example 3.

[0095] Comparative Example 16

[0096] Different from Example 3, in this comparative example S4, the third monomer is benzyl methacrylate, and the other operations are the same as those in Example 3.

[0097] Comparative Example 17

[0098] The difference from Example 3 is that in step S5, the amount of modified carbon black added is 15 times the total weight of the polycarboxylic acid dispersant and polyvinyl pyrrolidone, and the other operations are the same as Example 3.

[0099] Comparative Example 18

[0100] Different from Example 3, in this comparative example S5, an equal amount of polycarboxylic acid dispersant is used instead of polyvinyl pyrrolidone, and other operations are the same as in Example 3.

[0101] Comparative Example 19

[0102] Different from Example 3, this comparative example does not include S3, S4, and S5. An equal amount of polyvinyl pyrrolidone is used to replace the polycarboxylic acid dispersant. Other operations are the same as in Example 3.

[0103] Comparative Example 20

[0104] Different from Example 3, in this comparative example S6, an equal amount of acrylic acid is used instead of maleic anhydride, and other operations are the same as in Example 3.

[0105] Comparative Example 21

[0106] Different from Example 3, in this comparative example S6, an equal amount of maleic anhydride is used instead of acrylic acid, and other operations are the same as in Example 3.

[0107] Comparative Example 22

[0108] Different from Example 3, in this comparative example S6, polyethyleneimine was not added, and other operations were the same as in Example 3.

[0109] Comparative Example 23

[0110] Different from Example 3, in Comparative Example S6, polyethyleneimine is added at one time, and other operations are the same as in Example 3.

[0111] Comparative Example 24

[0112] Different from Example 3, in Comparative Example S6, the interval for adding each batch of polyethyleneimine was 20 minutes, and the other operations were the same as those in Example 3.

[0113] Comparative Example 25

[0114] Different from Example 3, in Comparative Example S6, the dripping time of each batch of polyethyleneimine is 3 minutes, and the other operations are the same as Example 3.

[0115] Comparative Example 26

[0116] Different from Example 3, in this comparative example S6, the addition amount of the secondary modified carbon black is 30% of the mass of the mixed liquid, and the other operations are the same as in Example 3.

[0117] 1. Dispersion test:

[0118] The functionalized carbon black prepared in the above embodiment and the comparative example was dispersed in anhydrous ethanol, the dispersion concentration was 10%, the ultrasonic power during dispersion was 200W, the dispersion time was 30min, and the dispersion was monitored for 80 days to see if precipitation was generated. The test results are shown in Table 1.

[0119] Table 1

[0120]

[0121]

[0122] It can be seen from the above test results that, compared with Comparative Examples 1-26, the present invention uses the first dispersant and the second dispersant to coat the preactivated carbon black, respectively, and finally modifies the polymer layer on the surface of the secondary modified carbon black, and the obtained functionalized carbon black has good dispersibility.

[0123] Specifically, in this embodiment, carbon black is modified step by step. First, sodium carboxymethyl cellulose, sodium dodecyl sulfate and Triton-100 are compounded to reduce the surface energy of carbon black through the dual effects of electrostatic repulsion and steric hindrance, thereby achieving preliminary dispersion of carbon black. Secondly, the self-made polycarboxylic acid dispersant forms chemical bonds or hydrogen bonds with the surface functional groups of carbon black through strong polar groups such as carboxyl and sulfonic acid groups, and the polyethylene glycol segment in the polycarboxylic acid dispersant provides a long-chain solvation end to enhance the steric hindrance stability. PVP, as a polymer dispersant, forms a chemical bond or hydrogen bond anchor with the surface functional groups of carbon black through van der Waals forces. It is adsorbed on the surface of carbon black, and its long-chain structure is synergistically compounded with polycarboxylic acid dispersants to further increase spatial steric hindrance and prevent secondary agglomeration of carbon black. Finally, choline chloride-acrylic acid-maleic anhydride copolymer forms a cross-linked network on the surface of secondary modified carbon black through free radical polymerization. The primary amine and secondary amine in the PEI molecule undergo a ring-opening reaction with the anhydride group of maleic anhydride to form an amide bond and release the carboxylic acid group at the same time. Polypropylene glycol diacrylate is cross-linked with polyethyleneimine under the action of a photoinitiator to form a three-dimensional network structure to anchor the carbon black particles, thereby improving the dispersibility of carbon black.

[0124] 2. Functional test:

[0125] The functionalized carbon black in the above-mentioned embodiments and comparative examples is added to the tire rubber material, specifically: 35 parts of natural rubber, 25 parts of butadiene rubber, and 16 parts of styrene-butadiene rubber are put into an internal mixer and mixed evenly, the mixing temperature is 65°C, the internal mixer speed is 45rpm, when the material temperature rises to 85°C, 2 parts of stearic acid, 2 parts of zinc oxide, 6 parts of functionalized carbon black, 6 parts of white carbon black, 0.5 parts of antioxidant A, and 1 part of plasticizer DCHP are added for mixing, the mixing time is 2 minutes, and the mixing temperature is 150°C; after the mixing is completed, the system temperature is lowered to 55°C, 1 part of sulfur and 1 part of accelerator DM are added, mixed for 2 minutes, the reaction temperature is adjusted to 135°C, and the tire rubber material is obtained by discharging.

[0126] The above tire rubber compound was subjected to performance tests, and the test methods and test results are as follows:

[0127] The tensile properties were tested according to GB / T528-2009, and the tear strength was tested according to GB / T529-2008. The wear resistance was tested according to GB / T1689-2014. The test results are shown in Table 2.

[0128] Table 2

[0129]

[0130]

[0131] It can be seen from the test results in Table 2 that, compared with Comparative Examples 1-26, the present invention performs multiple modifications on carbon black, and the obtained functionalized carbon black can well improve the performance of the tire tread rubber material when used in the tire tread rubber material.

[0132] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing functionalized carbon black, characterized in that: The following steps are involved: Treating carbon black with an oxidant solution to obtain preactivated carbon black; The preactivated carbon black is placed in a first dispersant solution for treatment to obtain a primary modified carbon black; The first dispersant solution is a mixed solution of sodium carboxymethyl cellulose, sodium dodecyl sulfate and Triton-100, wherein the mass ratio of sodium carboxymethyl cellulose, sodium dodecyl sulfate and Triton-100 is 1:(0.2-0.7):(0.1-0.4); the total weight of the first dispersant is 5-10wt% of the weight of the pre-activated carbon black; The first monomer, chain transfer agent and ethanol solution are mixed to obtain solution A, the second monomer, initiator and ethanol solution are mixed to obtain solution B, solution A is heated to 70-80°C, solution B is added dropwise to solution A, and the reaction is kept warm. After the reaction is completed, the solvent is removed and unreacted monomers are removed by dialysis, and the product is freeze-dried to obtain a prepolymer; the prepolymer, chain transfer agent and ethanol solution are mixed to obtain solution C, the third monomer, initiator and ethanol solution are mixed to obtain solution D, solution C is heated to 70-80°C, solution D is added dropwise to solution C, and the reaction is kept warm. After the reaction is completed, the solvent in the system is removed, the pH of the system is adjusted to be neutral, and the product is freeze-dried to obtain a polycarboxylic acid dispersant; the first monomer is polyethylene glycol methyl ether methacrylate, the second monomer is 2-acrylamide-2-methylpropanesulfonic acid; the third monomer is a mixture of phenoxyethyl methacrylate and benzyl methacrylate, and the mass ratio of the two is 1: (1-2); the chain transfer agent is thioglycolic acid, and the initiator is ammonium persulfate; the volume ratio of ethanol to deionized water in the ethanol solution is 1: (1-2); Adding a polycarboxylic acid dispersant and polyvinyl pyrrolidone to ethanol and stirring to obtain a second dispersant solution, adding primary modified carbon black to the second dispersant solution, performing ultrasonic dispersion treatment, centrifuging, precipitating and drying to obtain secondary modified carbon black; the mass ratio of the polycarboxylic acid dispersant and polyvinyl pyrrolidone is (1-3):1; the amount of primary modified carbon black added is 3-10 times the total weight of polyvinyl pyrrolidone and the polycarboxylic acid dispersant; The secondary modified carbon black is placed in a reaction solution of an organic polymer monomer and polyethyleneimine for treatment, and the polyethyleneimine is added in 3-4 batches, with an addition interval of 5-10 minutes for each batch, and each batch of polyethyleneimine is controlled to be added within 6-8 minutes; functionalized carbon black is obtained; the organic polymer monomer is a mixture of choline chloride, acrylic acid, maleic anhydride, and polypropylene glycol diacrylate.

2. The method for preparing functionalized carbon black according to claim 1, characterized in that: The oxidant solution is a hydrogen peroxide solution, and the concentration of the hydrogen peroxide solution is 30-50wt%; when the carbon black is treated with the hydrogen peroxide solution, the pH of the reaction system is 3-5, and the treatment is carried out for 6-20h under light-proof conditions, 100-500rpm, and 25-40°C.

3. The method for preparing functionalized carbon black according to claim 1, characterized in that: When the pre-activated carbon black is treated with the first dispersant solution, the pH of the treatment system is 8.0-9.

0. First, the pre-dispersion treatment is carried out at a stirring speed of 200-400 rpm for 10-13 minutes, and then the stirring speed is increased to 1000-2000 rpm, and stirred again for 10-20 minutes. Finally, auxiliary ultrasonic treatment is carried out at an ultrasonic power of 200-300 W for 17-20 minutes.

4. The method for preparing functionalized carbon black according to claim 1, characterized in that: In solution A, the concentrations of polyethylene glycol methyl ether methacrylate and thioglycolic acid are 0.1-0.12 g / ml and 0.00005-0.000053 g / ml, respectively; in solution B, the concentrations of 2-acrylamido-2-methylpropanesulfonic acid and ammonium persulfate are 0.5-0.53 g / ml and 0.004-0.005 g / ml, respectively; in solution C, the concentrations of prepolymer and chain transfer agent are 0.12-0.14 g / ml and 0.000032-0.000036 g / ml, respectively; in solution D, the concentrations of phenoxyethyl methacrylate and ammonium persulfate are 0.1-0.11 g / ml and 0.0032-0.0037 g / ml, respectively; the volume ratio of solution A to solution B is 6:(1-2); the volume ratio of solution C to solution D is 6:(1-2).

5. The method for preparing functionalized carbon black according to claim 1, characterized in that: The reaction process is specifically as follows: choline chloride, acrylic acid, and maleic anhydride are heated and stirred until they are clear and transparent, then polyethyleneimine is added in batches, stirring is continued until the solution is clear and transparent, polypropylene glycol diacrylate and photoinitiator-2959 are added, stirring and mixing to obtain a mixed solution, adding the above-mentioned secondary modified carbon black, stirring evenly, placing under an ultraviolet light source, irradiating the reaction, and centrifuging the reaction solution after the reaction is completed. After washing the precipitate with ethanol, freeze-drying is performed to obtain functionalized carbon black.

6. The method for preparing functionalized carbon black according to claim 5, characterized in that: The molar ratio of choline chloride, acrylic acid, maleic anhydride, polyethyleneimine, polypropylene glycol diacrylate, and photoinitiator-2959 is 1:1:1: (0.002-0.004): (0.01-0.02): (0.01-0.02).

7. The method for preparing functionalized carbon black according to claim 5, characterized in that: The addition amount of the secondary modified carbon black is 15-20% of the mass of the mixed liquid; the light source band during the irradiation reaction is 365nm, and the irradiation time is 1-5min.

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