WO2020253220A1

WO2020253220A1 - Thickening agent and preparation method therefor

Info

Publication number: WO2020253220A1
Application number: PCT/CN2020/070275
Authority: WO
Inventors: 张静; 王金剑; 俞波; 王耀国
Original assignee: 宁波锋成先进能源材料研究院
Priority date: 2019-06-20
Filing date: 2020-01-03
Publication date: 2020-12-24
Also published as: CN112111121B; CN112111121A

Abstract

A thickening agent and a preparation method therefor. The thickening agent comprises HPAM and a regulator. The regulator is graphene oxide modified by an organic polymer. A structural unit of the organic polymer comprises a group having the structural formula as represented by formula (I). Due to the addition of the regulator, a high viscosity can still be maintained in a high temperature environment.

Description

Thickener and preparation method thereof

Technical field

The application relates to a thickener and a preparation method thereof, and belongs to the technical field of additive materials.

Background technique

In the prior art, partially hydrolyzed polyacrylamide (HPAM) is used as a thickening agent; however, HPAM is easily hydrolyzed under high temperature conditions, and its viscosity decreases, which makes its thickening effect worse. Moreover, in industrial applications, the amount of HPAM Huge, a large number of HPAM use greatly increases the cost, which is not conducive to its further promotion and application.

It has become an urgent technical problem to reduce the amount of HPAM while ensuring the viscosity requirements. At present, there have been reports in the literature that using graphene nanosheets to increase the viscosity of HPAM, but the dispersion ability of graphene in HPAM is weak, and its viscosity The lifting capacity is limited.

Summary of the invention

According to one aspect of the present application, a thickener is provided. The thickener includes HPAM and a regulator. Due to the addition of the regulator, it can be used as a HPAM regulator, effectively increasing the viscosity of HPAM, reducing the amount of HPAM, and reducing Cost; and improve its high temperature stability, which provides the possibility for its application under high temperature conditions.

A thickener, the thickener includes HPAM and a regulator;

Wherein, the regulator includes graphene oxide modified with organic polymers;

The structural unit of the organic polymer contains a group having the structural formula represented by Formula I;

Wherein, R ', R "are independently selected from H, C ₁ ~ C ₆ alkyl group, hydroxyalkyl of any one.

Optionally, the thickener is composed of HPAM, modifier and solvent.

In this application, graphene oxide modified with organic polymers is used to adjust the viscosity of high-temperature HPAM, so that the viscosity of the viscous agent HPAM decreases with increasing temperature, that is, the regulator in this application is actually The above is the stabilizer of the viscous agent HPAM.

Preferably, the R'and R" are independently selected from any one of H, methyl, and hydroxymethyl.

For example, the structural unit of an organic polymer contains a group having the structural formula shown in formula I-1,

*—CO—NH ₂ Formula I-1.

For another example, the structural unit of the organic polymer contains a group having the structural formula shown in formula I-2

For another example, the structural unit of the organic polymer contains a group having the structural formula shown in formula I-3

Optionally, the organic polymer is at least one selected from polyacrylamide compounds;

The chemical formula of the polyacrylamide compound contains the structural unit shown in formula II:

R ¹ , R ² , and R ^{3 are} independently selected from H, methyl, ethyl or propyl.

In some possible embodiments, the chemical formula of the polyacrylamide compound contains the structural unit shown in formula II-1:

In other possible embodiments, the chemical formula of the polyacrylamide compound contains the structural unit shown in formula II-2:

In still other possible embodiments, the chemical formula of the polyacrylamide compound contains the structural unit shown in formula II-3:

Specifically, the polyacrylamide compound is selected from at least one of polyacrylamide, polymethacrylamide, polyN-methylolacrylamide, and polyN,N-dimethylacrylamide.

Preferably, the modifier is graphene oxide modified with polyacrylamide, denoted as GO-PAM. Specifically, the modifier is a PAM modified graphene oxide nanoparticle.

In this application, GO-PAM nanoparticles, which contain a large number of PAM segments, can be entangled with HPAM through hydrogen bond interactions, similar to the role of cross-linking points. Adding a small amount of GO-PAM can affect HPAM and its The dispersion system thickens and can improve its high temperature stability; in addition, because PAM and GO are connected by chemical bonding, the PAM group on GO-PAM interacts with HPAM, which can make GO-PAM PAM is stably dispersed in HPAM solution, and the dispersion system has high stability. In this application, graphene oxide modified with organic polymers is used to adjust the viscosity of high-temperature HPAM.

Optionally, the average particle size ratio of the graphene oxide modified by the organic polymer to the graphene oxide is 1 to 5:1.

Optionally, the average particle size of the graphene oxide modified with organic polymers is 100-500 nm.

Optionally, the preparation method of the regulator includes: polymerizing a mixture containing graphene oxide and organic polymer monomers to obtain the regulator.

Optionally, the particle size of the graphene oxide is 50-500 nm.

Optionally, the organic polymer monomer is selected from at least one of acrylamide, methacrylamide, N-methylolacrylamide, and N,N-dimethylacrylamide.

Preferably, the organic polymer monomer is acrylamide.

Preferably, the preparation method of the regulator includes: subjecting a mixture containing graphene oxide and acrylamide to polymerization reaction to obtain the regulator.

Optionally, the polymerization reaction is carried out in the presence of an initiator.

Optionally, the initiator includes at least one of sodium persulfate, ammonium persulfate, and potassium persulfate.

Optionally, the polymerization reaction is carried out in the presence of an initiator and a catalyst.

Optionally, the catalyst includes tetramethylethylenediamine.

For example, the polymerization reaction is carried out in the presence of ammonium persulfate and tetramethylethylenediamine.

Optionally, the mass ratio of the organic polymer monomer to the graphene oxide is 0.05 to 0.2:1.

Optionally, the mass ratio of the initiator to the organic polymer monomer is 0.001 to 0.1:1.

Optionally, the preparation method of the regulator includes at least the following steps:

a) Obtain a dispersion liquid containing graphene oxide;

b) Deoxidize the mixture containing the dispersion liquid and the organic polymer monomer, and then add the initiator;

c) Under the action of the initiator, the polymerization reaction is carried out to obtain the regulator.

a-1) Obtain a dispersion liquid containing graphene oxide;

b-1) Deoxidize the mixture containing the dispersion and the organic polymer monomer, and then add sodium persulfate;

c-1) The solution obtained in step b-1) is heated to 50-100° C., polymerized for 3-12 hours, and centrifuged to obtain the regulator.

Optionally, the mass ratio of sodium sulfate to organic polymer monomer is 0.01-0.1.

In a specific embodiment, the preparation method of the regulator includes the following steps:

Disperse graphene oxide in water to prepare a dispersion with a particle size of 50-500 nm;

Add acrylamide to the above dispersion, the mass of acrylamide is 5% to 20% of the mass of graphene oxide;

Perform deoxygenation operation on the above mixed solution, and then add sodium persulfate (1%-10% of the mass of acrylamide) to it;

React the above reaction solution at 50-100°C for 3-12 hours;

After the reaction is over, the product is collected by centrifugation after cooling, and the product is centrifuged and washed with water for 3-10 times to obtain GO-PAM.

a-2) Obtain a dispersion liquid containing graphene oxide;

b-2) Deoxidize the mixture containing the dispersion and the organic polymer monomer, and then add ammonium persulfate and tetramethylethylenediamine;

c-2) The solution obtained in step b-2) is polymerized at 25-50°C for 3-12 hours under ultraviolet light conditions to obtain the regulator.

Optionally, the mass ratio of ammonium persulfate to tetramethylethylenediamine is 0.1-2.

Optionally, the ratio of the mass of ammonium persulfate and tetramethylethylenediamine to the mass of the organic polymer monomer is 0.001-0.01:1.

Add acrylamide to the above dispersion liquid, the content of acrylamide is 5%-20wt% of the mass of graphene oxide;

Perform deoxygenation operation on the above mixed solution, and then add an initiator containing ammonium persulfate (APS) and tetramethylethylenediamine (TMEDA) (the mass ratio of APS to TMEDA is 0.1-2), and the quality of the initiator 0.1% to 1% of the mass of acrylamide;

Reacting the above reaction solution at 25-50°C under ultraviolet light conditions for 3-12 hours;

Optionally, the content of each component in the thickener is:

HPAM 90 to 99.95 parts by weight;

The regulator 0.05-10 parts by weight.

Optionally, the content of each component in the thickener is:

HPAM 90 to 99.95 parts by weight;

The regulator 0.05-10 parts by weight.

Solvent 1000 to 100,000 parts by weight.

Specifically, the solvent is water.

Preferably, the content of each component in the thickener is:

HPAM 99.9~99.95 parts by weight;

The regulator 0.05-0.1 parts by weight.

Preferably, the content of each component in the thickener is:

HPAM 99.9~99.95 parts by weight;

Regulating material 0.05 to 0.1 parts by weight;

Solvent 10000-100000 parts by weight.

According to another aspect of the present application, there is also provided a method for preparing the thickener described in any one of the above, which at least includes the steps:

1-1) Obtain a dispersion liquid I containing the regulator;

1-2) Obtain a solution I containing HPAM;

1-3) Obtain a mixture containing dispersion I and solution I, and then the thickener can be obtained.

In this application, the regulator can be formulated into a dispersion and then mixed with the HPAM solution. The dispersion can improve the thickening effect of HPAM, and is dispersed in water with HPAM to significantly increase the viscosity of the HPAM aqueous solution.

Optionally, the concentration of the dispersion I in step 1-1) is 0.0001 to 1 mg/ml.

2-1) Obtain a solution II containing HPAM;

2-2) Add the powdered regulator to solution II to obtain the thickener.

In this application, "HPAM" means partially hydrolyzed polyacrylamide;

"PAM" means polyacrylamide;

"GO" stands for graphene oxide.

The beneficial effects that this application can produce include:

1) The thickener provided by this application still maintains a relatively high viscosity under high temperature environment due to the addition of regulators.

2) The thickener provided by this application is added with the regulator GO-PAM, which can be used as a HPAM thickener, which can effectively increase the viscosity of HPAM, reduce the amount of HPAM, and reduce costs; and improve its high-temperature stability. The application under high temperature conditions provides the possibility.

3) In this application, GO-PAM can effectively thicken HPAM and solve the problem that HPAM is difficult to use due to the decrease in viscosity under high temperature conditions in the prior art. When heating from 25°C to 70°C, the viscosity is more than 85% of 25°C, and the viscosity changes very little with temperature.

4) If graphene oxide is directly used to increase the viscosity of HPAM solution, that is to say, only graphene oxide is used for viscosity increase. Graphene oxide will increase the viscosity of HPAM because graphene oxide has poor dispersibility in water and has weak interaction with HPAM. , The viscosity increasing effect is poor, especially after the temperature rises, the viscosity attenuation is very serious. This application can effectively solve this problem. GO-PAM has good dispersibility and can maintain the high temperature viscosity of HPAM.

Description of the drawings

Fig. 1 is an infrared image of GO-PAM prepared in one embodiment of this application.

Detailed ways

The application will be described in detail below with reference to the embodiments, but the application is not limited to these embodiments.

The sources of raw materials in the examples of this application are:

Graphene oxide was purchased from Changzhou Sixth Element Material Technology Co., Ltd.;

Acrylamide was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

HPAM was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. HPAM has a molecular weight of 2 million and a degree of hydrolysis of 20%.

In this application, a viscometer is used for viscosity testing (Guangzhou Southeast Science & Technology, DV2TLVTJ0)

The particle size test adopts a dynamic light scattering instrument to determine the particle size (Malvern, ZEN3700);

Infrared test is measured by infrared spectrometer (Thermo Fisher, Nicolet is50).

Example 1 Preparation of GO-PAM

Preparation of sample 1#:

A PAM modified graphene oxide nanoparticle, which can be used as a HPAM stabilizer, and the preparation method is as follows:

Disperse 20 mg of graphene oxide in 50 ml of water, and ultrasonically shear for 4 hours to obtain a graphene oxide nanoparticle dispersion with a particle size of about 50-200 nm; add 2 mg of acrylamide to the solution, and add nitrogen to drive oxygen for 20 minutes. 0.1mg sodium persulfate (the ratio of the mass of the monomer is 0.05:1), after stirring and dissolving, the reaction system is reacted at 80°C for 5 hours; after the reaction is completed, after the reaction liquid is naturally cooled, the product is collected by centrifugation; Disperse in water ultrasonically, centrifuge and wash three times to obtain GO-PAM, which is recorded as sample 1#.

Example 2 Preparation of GO-PAM

Preparation of sample 2#:

Disperse 20 mg of graphene oxide in 50 ml of water, and ultrasonically shear for 4 hours to obtain a graphene oxide nanoparticle dispersion with a particle size of about 50-200 nm; add 1 mg of acrylamide to the solution, and add nitrogen to drive oxygen for 20 minutes. 0.1mg sodium persulfate (the ratio of the mass of the monomer is 0.1:1), after stirring and dissolving, the reaction system is reacted at 50°C for 12 hours; after the reaction is completed, after the reaction liquid is naturally cooled, the product is collected by centrifugation; Disperse in water ultrasonically, centrifuge and wash three times to obtain GO-PAM, which is recorded as sample 2#.

Example 3 Preparation of GO-PAM

Preparation of sample 3#

Disperse 20mg of graphene oxide in 50ml of water, and ultrasonically shear for 4 hours to obtain a graphene oxide nanoparticle dispersion with a particle size of about 50-200nm; add 4mg of acrylamide to the solution, and add nitrogen to drive oxygen for 20 minutes. 0.004mg sodium persulfate (the ratio of the mass of the monomer is 0.001:1), after stirring and dissolving, the reaction system is reacted at 95°C for 3 hours; after the reaction is completed, after the reaction liquid is naturally cooled, the product is collected by centrifugation; Disperse in water ultrasonically, centrifuge and wash three times to obtain GO-PAM, which is recorded as sample 3#.

Example 4 Preparation of GO-PAM

Preparation of sample 4#:

Disperse 20 mg of graphene oxide in 50 ml of water, and ultrasonically shear for 4 hours to obtain a dispersion of graphene oxide nanoparticles with a particle size of about 50-500 nm; add 1 mg of acrylamide to the solution, and add nitrogen for 20 minutes after purging oxygen. 0.05mg (to the monomer mass ratio of 0.1:1) sodium persulfate and 0.05mg tetramethylethylenediamine, after stirring to dissolve, the reaction system was irradiated with ultraviolet light at 40°C for 9 hours; after the reaction, After the reaction solution is naturally cooled, the product is collected by centrifugation; the product is ultrasonically dispersed in water, centrifuged and washed three times to obtain GO-PAM, which is recorded as sample 4#.

Preparation of sample 5#:

The difference from the preparation method of sample 4# is that "reaction at 40°C for 9 hours" is replaced with "reaction at 25°C for 12 hours".

Example 5 Preparation of polymethacrylamide modified graphene oxide

The difference from Example 1 is that 4 mg of N-methylolacrylamide is added to the solution.

Example 6 Preparation of graphene oxide modified by poly-N,N-dimethylacrylamide

The difference from Example 1 is that 1 mg of N,N-dimethylacrylamide is added to the solution.

Example 7-17 Preparation of Thickener

Using partially hydrolyzed polyacrylamide HPAM as the research object, the thickening effect of GO-PAM nanoparticles on HPAM aqueous solution was studied (HPAM molecular weight is 2 million, hydrolysis degree is 20%).

Dissolve HPAM in water into solutions of different concentrations, and add different qualities of GO-PAM in Example 1 in powder form, and measure the viscosity changes at different temperatures and in the presence of GO-PAM nanoparticles in different proportions; The experimental results are shown in Table 1.

Example 18 Preparation of Thickener

Disperse GO-PAM in water ultrasonically to prepare dispersion I with a concentration of 1 mg/ml;

Dissolve HPAM in water into solution I with a concentration of 1 mg/ml;

Mix 1ml of Dispersion I with 999ml of Solution I to obtain the thickener.

Example 19 Preparation of Thickener

Disperse GO-PAM in water ultrasonically to prepare dispersion I with a concentration of 0.0001 mg/ml;

Dissolve HPAM in water into solution I with a concentration of 1 mg/ml;

Mix 1ml of Dispersion I with 999ml of Solution I to obtain the thickener.

Comparative example 1-3

The HPAM dissolved in water was configured into solutions of different concentrations, and the viscosity changes at different temperatures were measured. The experimental results are shown in Table 1.

Table 1 Experimental results

Comparing the 9 sets of data in Comparative Examples 1, 2, and 3, it can be seen that as the concentration of HPAM increases, the viscosity of the solution increases, and as the temperature increases, the viscosity of the solution decreases significantly, and the temperature rises from 25°C. At 70°C, the viscosity drops significantly, and the viscosity is only about 65% of that at 25°C. By comparing the first set of data of Comparative Example 1, Examples 7, 12, and 15, it can be seen that 0.1% of GO-PAM can be added. Significantly increase the viscosity of the PAM solution; comparative examples 7, 12, 15 can clearly see that the addition of GO-APM significantly increases the viscosity of the HPAM solution with respect to temperature stability. At 70°C, its viscosity is 87 at 25°C. %. Compared with the system without GO-PAM, the viscosity response to temperature becomes weaker, which proves that GO-PAM has temperature stability to HPAM solution.

Example 20 Characterization of GO-PAM

Infrared tests were performed on GO-PAM in Examples 1 to 4. The infrared test results showed that all samples in Examples 1 to 4 were successfully modified by PAM. From the infrared spectrum of GO-PAM, it can be clearly seen that the GO-PAM belongs to PAM. The characteristic absorption peaks of amide at 3191cm ^-1 and 1604cm ^-1 indicate the successful grafting of GO-PAM

To Sample 1 of Example # 1 is a typical representative embodiment, which is shown in FIG infrared data, it can be seen from Figure 1 1, in the GO ^{^{3 429cm -1, 1 627cm -1,}} 1 220cm -1 and 1 052cm ^-1 There are 4 obvious absorption peaks, which correspond to the stretching vibrations of the hydroxyl, carboxyl and epoxy groups on GO. The infrared spectrum of GO-PAM has obvious characteristic peaks of acrylamide, which proves the successful modification of PAM; among them, 3 415cm ^-1 , 3 191cm ^-1 , 1604cm ^-1 are characteristic absorption peaks belonging to amide; 2 937cm ^-1 are characteristic absorption peaks of methylene anti-symmetric stretching vibration; 1 656cm ^-1 are characteristic absorption peaks of carbonyl group ; 1 454cm ^-1 is the characteristic absorption peak of methylene deformation.

Example 21 Particle size test of GO-PAM

The GO-PAM in Examples 1 to 4 was tested for particle size, and the test results showed that the average particle size ratio of graphene oxide modified with organic polymer to graphene oxide was 1 to 5:1.

Taking sample 1# in Example 1 as a typical representative, the average particle size of GO-PAM is 200-300 nm, the average particle size of GO is 100-200 nm, and the ratio of the two is 1 to 3:1.

The above are only a few embodiments of the application, and do not limit the application in any form. Although the application is disclosed as above with preferred embodiments, it is not intended to limit the application. Anyone familiar with the profession, Without departing from the scope of the technical solution of the present application, making some changes or modifications using the technical content disclosed above is equivalent to an equivalent implementation case and falls within the scope of the technical solution.

Claims

A thickening agent, characterized in that the thickening agent includes HPAM and a regulator;

Wherein, the regulator includes graphene oxide modified with organic polymers;

The structural unit of the organic polymer contains a group having the structural formula represented by Formula I;

Wherein, R ', R "are independently selected from H, C 1 ~ C 6 alkyl group, hydroxyalkyl of any one.
The thickener according to claim 1, wherein the R'and R" are independently selected from any one of H, methyl, and hydroxymethyl.
The thickener according to claim 1, wherein the organic polymer is at least one selected from polyacrylamide compounds;

The chemical formula of the polyacrylamide compound contains the structural unit shown in formula II:

R 1 , R 2 , and R 3 are independently selected from H, methyl, ethyl or propyl.
The thickener according to claim 1, wherein the average particle size ratio of the graphene oxide modified by the organic polymer to the graphene oxide is 1 to 5:1.
The thickener according to claim 1, wherein the preparation method of the regulator comprises:

The mixture containing graphene oxide and organic polymer monomer is polymerized to obtain the regulator.
The thickener according to claim 5, wherein the particle size of the graphene oxide is 50-500 nm.
The thickener according to claim 5, wherein the organic polymer monomer is selected from the group consisting of acrylamide, methacrylamide, N-methylolacrylamide, and N,N-dimethylacrylamide At least one of.
The thickener according to claim 5, wherein the polymerization reaction is carried out in the presence of an initiator.
The thickener according to claim 8, wherein the initiator comprises at least one of sodium persulfate, ammonium persulfate, and potassium persulfate.
The thickener according to claim 5, wherein the mass ratio of the organic polymer monomer to the graphene oxide is 0.05 to 0.2:1.
The thickener according to claim 8, wherein the mass ratio of the initiator to the organic polymer monomer is 0.001 to 0.1:1.
The thickener according to claim 5, wherein the preparation method of the regulator comprises at least the following steps:

a) Obtain a dispersion liquid containing graphene oxide;

b) Deoxidize the mixture containing the dispersion liquid and the organic polymer monomer, and then add the initiator;

c) Under the action of the initiator, the polymerization reaction is carried out to obtain the regulator.
The thickener according to claim 12, wherein the preparation method of the regulator comprises at least the following steps:

a-1) Obtain a dispersion liquid containing graphene oxide;

b-1) Deoxidize the mixture containing the dispersion and the organic polymer monomer, and then add sodium persulfate;

c-1) The solution obtained in step b-1) is heated to 50-100° C., polymerized for 3-12 hours, and centrifuged to obtain the regulator.
The thickener according to claim 12, characterized in that the preparation method of the regulator comprises at least the following steps:

a-2) Obtain a dispersion liquid containing graphene oxide;

b-2) Deoxidize the mixture containing the dispersion and the organic polymer monomer, and then add ammonium persulfate and tetramethylethylenediamine;

c-2) The solution obtained in step b-2) is polymerized at 25-50°C for 3-12 hours under ultraviolet light conditions to obtain the regulator.
The thickener according to claim 1, wherein the content of each component in the thickener is:

HPAM 90～99.95 parts by weight;

The regulator 0.05-10 parts by weight.
A method for preparing a thickener according to any one of claims 1 to 15, characterized in that it at least comprises the steps:

1-1) Obtain a dispersion liquid I containing the regulator;

1-2) Obtain a solution I containing HPAM;

1-3) Obtain a mixture containing dispersion I and solution I, and then the thickener can be obtained.
The preparation method according to claim 16, wherein the concentration of the dispersion I in step 1-1) is 0.0001 to 1 mg/ml.
A method for preparing a thickener according to any one of claims 1 to 15, characterized in that it at least comprises the steps:

2-1) Obtain a solution II containing HPAM;

2-2) Add the powdered regulator to solution II to obtain the thickener.