CN114574001A - Method for preparing hydrophilic carbon black through biomimetic modification of phenolic amine and hydrophilic carbon black - Google Patents

Abstract

The invention discloses a method for preparing hydrophilic carbon black by biomimetic modification of phenolic amine and the hydrophilic carbon black. The method comprises the following steps: (1) dispersing carbon black in water to form a carbon black dispersion; (2) mixing plant polyphenol and polyamine to prepare a phenol amine solution; (3) adding the carbon black dispersion liquid prepared in the step (1) into the phenol amine solution in the step (2), and simultaneously adding a buffer solution to adjust the pH value to 8.0-11; (4) and (4) continuously stirring the mixed solution obtained in the step (3) at 15-80 ℃ for reaction, and drying after cleaning to obtain the hydrophilic carbon black. The method successfully coats the surface of the carbon black with a hydrophilic polymer, so that the content of oxygen and nitrogen on the surface of the carbon black is obviously increased, and the modified carbon black has good dispersibility and stability in water.

Description

A kind of method for preparing hydrophilic carbon black by biomimetic modification of phenolamine and hydrophilic carbon black

technical field

The invention relates to the technical field of carbon black materials, in particular, to modified carbon black and a preparation method thereof, and more particularly to a method for preparing hydrophilic carbon black by biomimetic modification of phenolamine and the hydrophilic carbon black.

Background technique

Carbon black is a nanoparticle agglomerate formed by the cracking and cyclization of hydrocarbon compounds at high temperature. It has excellent colorability, blackness value, weather resistance and chemical stability. Compared with other black organic dyes and inorganic pigments, carbon black has better comprehensive properties, rich sources and low price. Therefore, carbon black is a good ingredient for printing inks, coatings, paints, plastics and inkjets. For environmental and cost reasons, the solvent system for these applications is often water and requires good dispersion of the carbon black. However, carbon black is a nanoparticle with a small primary particle size (10-500 nm), high surface energy, and few hydrophilic functional groups on the surface. It is easy to aggregate into larger particles, and it is difficult to stably disperse in different systems. These defects It limits the full play of carbon black performance. Therefore, it is of great significance to improve the hydrophilicity of carbon black and improve its dispersion and stability in aqueous solution.

The main factors affecting the dispersion stability of carbon black are the affinity between carbon black and the dispersion medium, the steric resistance and electrostatic repulsion between carbon black particles. In order to uniformly disperse and stably exist carbon black in an aqueous system, the main preparation methods include dispersant modification, oxidative modification, water-soluble polymer grafting and polymer coating.

Dispersant modification is the use of surfactants to reduce the surface energy of carbon black particles, so that the surface of carbon black is inactive, thereby effectively preventing particles from reaggregating or using the different polarities of carbon black and molecular chain charges to cause mutual adsorption to make carbon black. The black particles are uniformly dispersed in the solvent. However, for the carbon black modified by dispersant, the force between them is physical adsorption. Under the strong shearing or other action of the outside world, the dispersant may fall off from the surface of the carbon black, thereby causing the carbon black to agglomerate again.

Oxidation modification is divided into gas phase oxidation, liquid phase oxidation, plasma oxidation and anodic oxidation. Oxidation modification is to increase the oxidation of carbon black surface by some strong oxidants or electrochemical oxidation method to increase the number of oxygen-containing functional groups and improve the hydrophilicity of carbon black. However, the use of strong oxidants puts forward higher requirements for equipment, and the process conditions are relatively harsh.

Water-soluble polymer grafting is to connect hydrophilic polymers to the surface of carbon black through chemical bonds. A polar hydrophilic polymer chain is introduced into carbon black, and the hydrophilic polymer chain is dispersed around the carbon black to generate a certain steric hindrance, thereby preventing the agglomeration of carbon black particles and making the carbon black in the polar solution. maintain good stability. However, due to the few active functional groups on the surface of carbon black, and the use of free radical polymerization in the reaction process, the grafting efficiency is low, and it is difficult to popularize and use in industry.

The purpose of polymer coating modification is to deposit a layer of hydrophilic polymer on the surface of carbon black, so that carbon black can be stably dispersed in water. Three common methods are heterogeneous polymerization coating, microemulsion polymerization coating and phase separation coating modification. When the carbon black is hydrophilically modified by the polymer coating method, the selection of the modified substance is very important.

Chinese invention patent CN106497151A uses amino acid-rich fermentation broth to modify the surface of carbon black, and increases the number of hydrophilic amino groups and carboxyl groups on the surface of carbon black under the action of microorganisms. However, the natural fermentation process of this method requires 20 to 30 days, resulting in a long preparation process and low production efficiency.

Chinese invention patent CN102337047A prepares hydrophilic carbon black by adsorbing the lipophilic end of anionic surfactant to the surface of carbon black particles to form a uniform coating layer. The strength of the physical adsorption between carbon black and anionic surfactants is low, and the coating layer tends to fall off during storage, stirring and dispersing, resulting in a decrease in the hydrophilicity of carbon black.

It can be seen that the surface coating of carbon black can only be fully utilized by selecting a suitable modified substance to give full play to the polymer coating method.

Therefore, finding a suitable raw material to coat carbon black to prepare high hydrophilic carbon black has become one of the focuses of researchers.

SUMMARY OF THE INVENTION

In order to solve the problems in the prior art, the present invention provides a method for preparing hydrophilic carbon black by biomimetic modification of phenolamine and the hydrophilic carbon black. The invention adopts plant polyphenols and polyamines to successfully coat a layer of hydrophilic coating on the surface of carbon black, increases the number of hydrophilic functional groups on the surface of carbon black particles, and effectively improves the dispersibility and stability of carbon black particles in an aqueous solution sex.

One of the objectives of the present invention is to provide a method for preparing hydrophilic carbon black by biomimetic modification of phenolamines.

include:

(1) disperse carbon black in water to form carbon black dispersion;

(2) Mixing plant polyphenols and polyamines to prepare phenolamine solution;

(3) adding the carbon black dispersion liquid prepared in step (1) to the phenolamine solution in step (2), and adding a buffer solution to adjust the pH to 8.0-11;

(4) The mixed solution obtained in step (3) is continuously stirred and reacted, and the hydrophilic carbon black is obtained after washing and drying.

In a preferred embodiment of the present invention,

In step (1), the concentration of the carbon black dispersion liquid is 1g/L～15g/L, preferably 4～10g/L.

In a preferred embodiment of the present invention,

In step (2),

Described plant polyphenols are natural phenols containing catechol or bipyloroglucinol structure; preferably catechol, tannin, gallic acid, catechin, gallocatechin, epicatechin gallate One or a combination of acid esters and gallocatechin gallate; more preferably tannins;

The polyamine is a combination of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

In a preferred embodiment of the present invention,

The mass ratio of the plant polyphenol to the polyamine is 1:(1-8), preferably 1:(4-6).

In a preferred embodiment of the present invention,

The concentration of the plant polyphenol is 0.5-6 mg/mL, preferably 2-4 mg/mL.

In a preferred embodiment of the present invention,

In step (3), the mass ratio of carbon black to plant polyphenols is 0.2-6.0; preferably 0.5-3.

In a preferred embodiment of the present invention,

step (3),

The buffer solution is one of Tris-HCl buffer, glycine-NaOH buffer, and sodium carbonate-sodium bicarbonate buffer.

In a preferred embodiment of the present invention,

step (4),

The reaction temperature is 15-80°C; preferably 20-40°C; and/or,

The stirring speed is 100-500 revolutions/min.

In a preferred embodiment of the present invention,

step (4),

The reaction time under catalyst-free conditions is 2-20h, preferably 5-10h.

React under catalyst conditions for 10 to 120 minutes; preferably 30 to 60 minutes;

The catalyst is one or a combination of hydrogen peroxide, peracetic acid, ammonium persulfate, potassium permanganate and sodium hypochlorite.

The mass ratio of catalyst to plant polyphenol is 1:(20-80), preferably 1:(20-60).

Another object of the present invention is to provide a hydrophilic carbon black obtained by the method.

The oxygen atoms on the surface of the hydrophilic carbon black are 10-35% of the total amount of carbon, oxygen and nitrogen; preferably 20-32%;

The nitrogen atoms on the surface of the hydrophilic carbon black are 5-15% of the total amount of carbon, oxygen and nitrogen; preferably 6-13%

The increase in the content of oxygen atoms and nitrogen atoms after the carbon black is modified by this method can indicate that the carbon black is covered by the polymer, and the oxygen and nitrogen elements both come from the hydroxyl-OH and amino-NH ₂ in the polymer, which indicates that the carbon black has a pro- water-based indicator.

The present invention can adopt the following technical scheme specifically:

A method for preparing hydrophilic carbon black by biomimetic modification of phenolamine, comprising the following steps:

(1) the carbon black is initially dispersed in the aqueous solution by mechanical stirring;

(2) configure a blended solution of plant polyphenols and polyamines;

Described plant polyphenols are natural phenols containing catechol or bipyloroglucinol structure: preferably catechol, tannin, gallic acid, catechin, gallocatechin, epicatechin gallate One or a combination of acid ester and gallocatechin gallate, more preferably tannic acid.

The polyamine is one or a combination of diethylenetriamine (DETA), triethylenetetramine, and tetraethylenepentamine; preferably, diethylenetriamine.

(3) placing the carbon black water slurry prepared in step (1) in the phenolamine solution in step (2), and adding a buffer solution to adjust the pH to 8.0-11;

The buffer solution is one of Tris-HCl buffer, glycine-NaOH buffer and sodium carbonate-sodium bicarbonate buffer; preferably Tris-HCl buffer.

(4) The mixed solution obtained in step (3) is continued to be stirred and reacted, washed and dried to obtain hydrophilic carbon black.

The carbon blacks include all commercial carbon blacks.

The stirring rate is 100～500 rev/min;-

The mass ratio of the plant polyphenol to the polyamine is 1:(1-8); preferably, it is 1:(4-6).

The concentration of the plant polyphenol is 0.5-6 mg/mL; preferably, it is 2-4 mg/mL.

The mass ratio of carbon black to plant polyphenols is 0.2-6.0; preferably 0.5-3.

The reaction time of the reaction without catalyst is 2-20h; preferably, it is 5-10h.

The reaction is carried out under the condition of a catalyst for 10-120 min; preferably 30-60 min.

The catalyst is one or more selected from hydrogen peroxide, peracetic acid, ammonium persulfate, potassium permanganate, and sodium hypochlorite; preferably, it is ammonium persulfate.

The reaction temperature is 15-80°C; preferably 20-40°C.

The reaction principle of the present invention is as follows: under alkaline conditions, plant polyphenols containing catechol or pyrogallol structures are easily oxidized by oxygen in the air or catalysts, and the oxidation product contains a large amount of o-quinone structure, and the There are active unsaturated carbonyl groups in benzoquinone, which can undergo Michael addition reaction with nucleophiles (eg, polyamines). In addition, o-benzoquinone can also undergo Schiff base reaction with polyamines. The two reactions made plant polyphenols and polyamines form cross-linked polymers and deposited on the surface of carbon black, providing carbon black with abundant hydrophilic functional groups and enhancing the hydrophilicity of carbon black.

Compared with other modification methods, the preparation method of hydrophilic carbon black provided by the present invention has the following beneficial effects:

1) the present invention is simple to operate, safe and environmentally friendly, and the plant polyphenols are abundant in nature, with low price and low cost;

2) The plant polyphenol and polyamine system adopted in the present invention has the advantages of being environmentally friendly, low in corrosion to equipment, mild in reaction conditions and fast in reaction speed;

3) The present invention coats a layer of dense, uniform and permanent hydrophilic polymer on the surface of the carbon black, increasing the hydrophilic functional groups on the surface of the carbon black, so that the carbon black has excellent hydrophilicity.

The experimental results show that the preparation method of the hydrophilic carbon black provided by the present invention successfully coats a hydrophilic polymer on the surface of the carbon black, so that the content of oxygen atoms on the surface of the carbon black increases from the initial 1.8at.% to 30at. %, the nitrogen atom content increased from the initial 0.9 at. % to 11 at. %, which indicated that the content of functional groups on the surface of carbon black was greatly increased, so that the modified carbon black had good dispersibility and stability in water.

Description of drawings

Fig. 1 is the X-ray photoelectron spectroscopy (XPS) broad spectrum of carbon black N134;

FIG. 2 is an X-ray photoelectron spectroscopy (XPS) broad spectrum of carbon black of Example 1. FIG.

Figure 3 is a scanning electron microscope (SEM) image of carbon black N134;

4 is a scanning electron microscope (SEM) image of carbon black of Example 1

Figure 5 is the experimental result of standing and settling for 0 days;

Fig. 6 is the experimental result after standing and settling for 90 days;

Among them, in Figures 5 and 6, the left side is the carbon black N134 sample, and the right side is the carbon black sample of Example 1.

Detailed ways

The present invention will be described in detail below in conjunction with the specific drawings and examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. SUMMARY OF THE INVENTION Some non-essential improvements and adjustments made to the present invention still fall within the protection scope of the present invention.

The raw materials used in the examples are all commercially available products.

Example 1

(1) get 200mg of carbon black N134 and add it to 50mL of deionized water, and stir for 20min at a stirring speed of 200 rev/min to form a uniform carbon black water slurry;

(2) respectively take 200mg of tannic acid and 600mg of diethylenetriamine and add it to 50mL of deionized water, mix well after shaking;

(3) pouring the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), and adding Tris-HCl buffer to adjust pH to 10;

(4) Continue to react the blended solution of step (3) at a stirring rate of 200 rpm for 5 hours at 20° C., after the reaction is completed, wash and dry to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

The XPS broad spectrum and SEM images of pristine carbon black N134 are shown in Figure 1 and Figure 3, respectively. The XPS broad spectrum and SEM images of the modified hydrophilic carbon black are shown in Figure 2 and Figure 4, respectively. The sedimentation results of the original carbon black N134 and the modified carbon black are shown in Figures 5 and 6.

It can be seen from the figure that there is no obvious nitrogen peak in the XPS broad spectrum of the original carbon black N134 in Figure 1, while the modified carbon black in Figure 2 has an obvious nitrogen peak, and the oxygen peak is also Significant enhancement, which indicates that poly(tannic acid-diethylenetriamine) is deposited on the surface of carbon black.

In Figure 3, the aggregate size of the unmodified carbon black N134 is large and continuously distributed like a grape bunch, while the aggregate size of the modified carbon black in Figure 4 is significantly reduced, indicating that the modified carbon black has Strong hydrophilicity.

After 90 days of standing and settling in Figure 6, the carbon black N134 completely settled to the bottom of the bottle, on the contrary, the modified carbon black coated with poly(tannic acid-diethylenetriamine) still maintained good hydrophilicity and formed extremely stable carbon black suspensions.

Example 2

(1) get 400mg carbon black N134 and add it to 50mL deionized water, stir 20min with the stirring speed of 400 rev/min, form uniform carbon black water slurry;

(2) respectively take 200mg of tannic acid and 800mg of diethylenetriamine and add it to 50mL of deionized water, mix well after shaking;

(3) pouring the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), and adding Tris-HCl buffer to adjust pH to 8.5;

(4) Continue to react the blended solution of step (3) at a stirring rate of 400 rev/min for 15 hours at 30° C., after the reaction, wash and dry to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

Example 3

(1) Get 400mg of carbon black N134 and add it to 50mL of deionized water, and stir for 20min at a stirring speed of 200 rev/min to form a uniform carbon black water slurry;

(2) respectively take 300mg of tannic acid and 800mg of diethylenetriamine and add it to 50mL of deionized water, mix well after shaking;

(3) pouring the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), adding Tris-HCl buffer to adjust pH to 9;

(4) 5 mg of ammonium persulfate was added to the blended solution in step (3), and the reaction was continued for 20 min at a stirring rate of 200 rpm at 20° C. After the reaction was completed, washed and dried to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

Example 4

(1) get 200mg of carbon black N134 and add it to 50mL of deionized water, and stir for 20min at a stirring speed of 500 rev/min to form a uniform carbon black water slurry;

(2) respectively take 200mg of gallic acid and 800mg of triethylenetetramine and add it to 50mL of deionized water, mix well after shaking;

(3) pouring the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), and adding glycine-NaOH buffer to adjust the pH to 11;

(4) Continue to react the blended solution of step (3) at a stirring rate of 500 rev/min for 8 hours at 20° C., after the reaction, wash and dry to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

Example 5

(1) get 200mg of carbon black N134 and add it to 50mL of deionized water, and stir for 20min at a stirring speed of 400 rev/min to form a uniform carbon black water slurry;

(2) respectively take 200mg of catechin and 1200mg of tetraethylene pentamine and add it to 50mL of deionized water, mix well after shaking;

(3) pour the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), add sodium carbonate-sodium bicarbonate buffer simultaneously to adjust pH to be 9;

(4) Continue to react the blended solution of step (3) at a stirring rate of 400 rev/min for 15 hours at 20° C., after the reaction, wash and dry to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

Example 6

(1) get 400mg carbon black N134 and add it to 50mL deionized water, stir 20min with the stirring speed of 400 rev/min, form uniform carbon black water slurry;

(2) respectively take 200mg of catechin and 800mg of tetraethylene pentamine and add it to 50mL of deionized water, mix well after shaking;

(3) pour the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), add sodium carbonate-sodium bicarbonate buffer to adjust pH to 8.5;

(4) 10 mg of sodium hypochlorite was added to the blended solution in step (3), and the reaction was continued for 50 min at a stirring rate of 400 rev/min at 20° C. After the reaction was completed, washed and dried to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

Example 7

(1) Get 10g of carbon black N134 and add it to 1L of deionized water, and stir for 20min at a stirring speed of 500 rev/min to form a uniform carbon black water slurry;

(2) get the tannic acid of 10g and the diethylenetriamine of 40g respectively and join in the deionized water of 1L, mix after shaking;

(3) pouring the carbon black water slurry prepared in step (1) into the phenolamine solution in step (2), and adding Tris-HCl buffer to adjust pH to 10;

(4) Continue to react the blended solution of step (3) at a stirring rate of 500 rev/min for 12 hours at 40° C., after the reaction, wash and dry to obtain hydrophilic carbon black.

The atomic percentages of surface elements of the modified carbon black samples are shown in Table 1.

Table 1 Relative atomic percentage of carbon black N134 and modified carbon black surface elements in Examples 1-6

It can be seen from the data in Table 1 that the carbon black modified by the method of the present invention is successfully coated with a hydrophilic polymer on the surface of the carbon black, and the content of oxygen and nitrogen on the surface of the carbon black increases significantly, which shows that The content of functional groups on the surface of carbon black is greatly increased, so that the modified carbon black has good dispersibility and stability in water.

Claims (10)

1. a method for preparing hydrophilic carbon black by biomimetic modification of phenolamine, is characterized in that described method comprises: (1) disperse carbon black in water to form carbon black dispersion; (2) Mixing plant polyphenols and polyamines to prepare phenolamine solution; (3) adding the carbon black dispersion liquid prepared in the step (1) to the phenolamine solution in the step (2), and adding a buffer solution to adjust the pH to 8.0-11; (4) The mixed solution obtained in step (3) is continuously stirred and reacted, and the hydrophilic carbon black is obtained after washing and drying. 2. the method for preparing hydrophilic carbon black as claimed in claim 1 is characterized in that: In step (1), the concentration of the carbon black dispersion liquid is 1g/L～15g/L, preferably 4～10g/L. 3. the method for preparing hydrophilic carbon black as claimed in claim 1 is characterized in that: In step (2), Described plant polyphenols are natural phenols containing catechol or bipyloroglucinol structure; preferably catechol, tannin, gallic acid, catechin, gallocatechin, epicatechin gallate one or a combination of gallate, gallocatechin gallate; and/or, The polyamine is one or a combination of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. 4. the method for preparing hydrophilic carbon black as claimed in claim 3 is characterized in that: The mass ratio of the plant polyphenol to the polyamine is 1:(1-8), preferably 1:(4-6). 5. the method for preparing hydrophilic carbon black as claimed in claim 4 is characterized in that: The concentration of the plant polyphenol is 1-10 mg/mL, preferably 4-6 mg/mL. 6. the method for preparing hydrophilic carbon black as claimed in claim 1 is characterized in that: In step (3), the mass ratio of carbon black to plant polyphenols is 0.2-6; preferably 0.5-3. 7. the method for preparing hydrophilic carbon black as claimed in claim 1 is characterized in that: step (3), The buffer solution is one of Tris-HCl buffer, glycine-NaOH buffer, and sodium carbonate-sodium bicarbonate buffer. 8. the method for preparing hydrophilic carbon black as claimed in claim 1 is characterized in that: step (4), The reaction temperature is 15-80°C; preferably 20-40°C; and/or, The stirring speed is 100-500 revolutions/min. 9. the method for preparing hydrophilic carbon black as claimed in claim 1 is characterized in that: step (4), Under catalyst-free conditions, the reaction time is 2-20h, preferably 5-10h; React under catalyst conditions for 10 to 120 minutes; preferably 30 to 60 minutes; The catalyst is one or a combination of hydrogen peroxide, peracetic acid, ammonium persulfate, potassium permanganate and sodium hypochlorite; The mass ratio of the catalyst to the plant polyphenol is 1:(20-80), preferably 1:(20-60). 10. A hydrophilic carbon black obtained by the method according to one of claims 1 to 9, characterized in that: The oxygen atoms on the surface of the hydrophilic carbon black are 10-35% of the total amount of carbon, oxygen and nitrogen; preferably 20-32%; The nitrogen atoms on the surface of the hydrophilic carbon black are 5-15% of the total amount of carbon, oxygen and nitrogen; preferably 6-13%.

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