CN112210042A - Preparation method of white carbon black-biogum composite water-absorbing material - Google Patents

Abstract

The invention discloses a preparation method of a water-absorbing material, which comprises the step of carrying out polymerization reaction on biological glue and acrylic monomers to generate the water-absorbing material, and is characterized in that: and adding a certain amount of white carbon black into the polymerization reaction. Compared with the prior art that oil shale semicoke, sepiolite, loess and the like are used as inorganic components, the white carbon black is used as the inorganic component, so that the salt absorption performance of the water absorbing material can be obviously improved, the water absorption rate of 0.9% sodium chloride solution reaches more than 80g/g, and the water absorbing material can be widely applied to the fields of water-saving agriculture, ecological restoration and the like.

Description

Preparation method of white carbon black-biogum composite water-absorbing material

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a preparation method of an inorganic-biological glue composite water-absorbing material.

Background

The shortage of fresh water resources is one of the most serious problems in the world today. It threatens the basic living conditions of human beings, restricts the living quality of human beings and generates great harm to the living and development of human beings. The current state of water resources in China is not optimistic, particularly in northern areas of China, the water resource amount and the cultivated land area of a drought area respectively account for 17 percent and 64 percent of the country, and are only 1/4 and 1/9 in southern areas. Meanwhile, limited water resources are not effectively utilized, most of water is evaporated by the soil surface and is lost, and the amount of the water in the northwest semiarid region of China generally accounts for 1/4-1/2 of the total water consumption of crops, and accounts for 55-65% of annual precipitation. Therefore, reducing the evaporation from the soil surface is an important means to improve the water use efficiency of the farmland. Among them, increasing the water retention and supply capacity of soil is the most direct and effective way to reduce soil surface evaporation.

The oil shale semicoke is solid waste generated in the process of producing shale oil by a low-temperature dry distillation technology, is mainly used for clinker blending of a cement plant and coal blending of fuel of a power plant at present, but has smaller and smaller market demand along with the increase of environmental protection, and can only be solved by adopting an open-air stacking mode. Therefore, a new way for recycling the oil shale semi-coke waste is found to be an urgent problem to be solved. The main mineral of the oil shale semi-coke is flaky kaolinite, the content of silicon dioxide is high, and organic matters such as carbon and the like are secondarily contained. Therefore, the oil shale semicoke is fully and reasonably utilized, so that the waste is changed into valuable, the added value of the waste is improved, better economic benefit is generated, and the aim of environmental protection can be fulfilled.

Chinese patent CN 111171839A discloses a method for preparing a composite water-retaining agent by using oil shale semi-coke and clay minerals as inorganic components, and specifically discloses: under the stirring of 300rpm, 1.0g of xanthan gum is dissolved in 40mL of water, and then 5g of oil shale semi-coke and 2.5g of sepiolite are added to obtain uniform dispersion liquid; introducing nitrogen to remove oxygen for 30min, adding 1.8g of ammonium persulfate, preserving heat at 80 ℃ for 5min, dropwise adding a monomer and cross-linking agent mixed solution (0.25 g of methylene bisacrylamide is dissolved in 20g of acrylic acid to form a mixed solution), and polymerizing at 80 ℃ for 3 h; drying in an oven at 100 ℃ for 4h to obtain a product, crushing, and sieving with a 40-80 mesh sieve. The swelling degree of the water-retaining agent in pure water is 520g/g, and the swelling degree in 0.9% sodium chloride solution is 45 g/g.

The preparation of biogum-loess composite material and research on water retention and sand fixation performance (Von Enke, Master's academic thesis of northwest university, 2015) disclose that Guar Gum (GG) or Xanthan Gum (XG), Acrylic Acid (AA) and loess (loess) are used as raw materials, Ammonium Persulfate (APS) is used as an initiator, N, N' -Methylene Bisacrylamide (MBA) is used as a cross-linking agent, and an aqueous solution polymerization method is adopted to prepare the guar gum grafted polyacrylic acid/loess (GG-g-PAA/loess) composite super absorbent resin and the xanthan grafted polyacrylic acid/loess (XG-PAA/loess) composite super absorbent resin. The maximum water absorption rates (swelling degrees) of GG-g-PAA/loess and XG-PAA/loess in distilled water reach 602g/g and 610g/g respectively, and the maximum water absorption rates in a 0.9% sodium chloride solution reach 45g/g and 54g/g respectively.

Although the inorganic-biogum composite water-absorbing material has higher water-absorbing rate to distilled water, the performance of absorbing 0.9% sodium chloride solution is not high, and in practical application, most of liquid absorbed by the water-absorbing material is electrolyte solution, such as urine, blood, fertilizer water and the like, so that the improvement of the salt-absorbing performance of the inorganic-biogum composite water-absorbing material has important application significance.

Disclosure of Invention

Based on the problem of poor salt absorption of the existing inorganic-biological glue composite water absorbing material, the invention aims to provide a method for preparing the inorganic-biological glue composite water absorbing material so as to improve the salt absorption performance of the water absorbing material.

A preparation method of a water absorbing material comprises the polymerization reaction of biological glue and acrylic monomers to generate the water absorbing material, and is characterized in that: and adding a certain amount of white carbon black into the polymerization reaction.

Preferably, the specific process of the preparation method comprises the following steps:

adding the biogel into water, uniformly mixing, and adding an initiator;

and adding acrylic monomers, a cross-linking agent and white carbon black, and then heating for reaction to generate the water absorbing material.

Preferably, the biogum is at least one of tarragon gum, artemisia glue, xanthan gum and guar gum.

Preferably, the acrylic monomer is acrylic acid and/or acrylamide.

Preferably, the cross-linking agent is at least one of N, N' -methylenebisacrylamide, citric acid, boric acid, and borax.

Preferably, the initiator is ammonium persulfate and/or potassium persulfate.

Preferably, the reaction temperature is 65-80 ℃ and the reaction time is 1-3 hours.

Preferably, the mass percent content of the white carbon black in the water absorbing material is 1-6%, and most preferably, the mass percent content of the white carbon black is 2%.

Preferably, the white carbon black is oil shale semi-coke white carbon black.

Preferably, the oil shale semi-coked white carbon black is prepared by a method comprising the following steps:

crushing and calcining the oil shale semi-coke;

and then soaking the calcined oil shale semi-coke with acid to obtain the oil shale semi-coke white carbon black.

More preferably, the powder is passed through a 200 mesh screen after grinding.

More preferably, the calcination temperature is 800-900 ℃ and the calcination time is 2-3 hours.

More preferably, sulfuric and/or nitric acid impregnation is used.

More preferably, the dipping temperature is 90-100 ℃ and the time is 10-12 hours.

Compared with the prior art that oil shale semicoke, sepiolite, loess and the like are used as inorganic components, the invention unexpectedly discovers that the white carbon black is used as the inorganic component, so that the salt absorption performance of the inorganic-biological glue composite water absorption material can be obviously improved, and the water absorption rate of the inorganic-biological glue composite water absorption material to 0.9 percent sodium chloride solution reaches more than 80 g/g.

Drawings

FIG. 1 is an infrared spectrum of a composite super absorbent resin prepared by the present invention.

FIG. 2 is an SEM image of a composite super absorbent resin prepared by the present invention.

FIG. 3 is a diagram showing the water (salt) absorption performance of the composite super absorbent resin when the content of the oil shale semi-coke white carbon black is different.

FIG. 4 is a diagram showing the water retention performance of the composite super absorbent resin at different temperatures.

Detailed Description

The technical solution of the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

The white carbon black-biogum composite water-absorbing material is obtained by carrying out polymerization reaction on raw materials comprising biogum, acrylic monomers and white carbon black.

The specific process comprises the following steps:

adding the biogel into water, uniformly mixing, and adding an initiator;

and adding acrylic monomers, a cross-linking agent and white carbon black, heating and carrying out polymerization reaction to generate the white carbon black-biological adhesive composite water absorbing material.

In some embodiments, the amount of white carbon black in the water absorbent material (dry weight) is controlled to be 1-6% by mass, such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, or a range therebetween, such as 1-5.5%, 1-4%, 1.5-3%, 2-3%. Most preferably, the white carbon black is 2% by mass.

In some embodiments, the biogel is selected from at least one of tarragon gum, artemisia glue, xanthan gum and guar gum.

The biogel is added into water and then heated, which is beneficial to the dissolution/dispersion of the biogel to form uniform solution/dispersion liquid. Preferably, the heating temperature can be controlled to be 60-75 ℃. And (3) dripping an initiator at the temperature and preserving heat for a certain time to fully activate the initiator, wherein the preferable heat preservation time is 10-20 min.

In some embodiments, the initiator is selected from ammonium persulfate and/or potassium persulfate. Preferably, the mass ratio of the initiator to the biogel is 1: 6-1: 12, and the mass ratio of the initiator to the biogel is 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, or the range between the initiator and the biogel, such as 1: 7-1: 11, 1: 7-1: 10, 1: 8-1: 9.

In some embodiments, after the initiator is added, the temperature of the system is reduced to below 50 ℃, preferably to 40-80 ℃.

In some embodiments, the acrylic monomer is selected from acrylic acid and/or acrylamide. Preferably, the mass ratio of the acrylic monomer to the biogel is 20: 1-1: 5, and the mass ratio of the acrylic monomer to the biogel is 20:1, 19:1, 18:1, 17:1, 16:1, 15:1, 14:1, 13:1, 12:1, 11:1, 10:1, 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:2, 1:3, 1:4, 1:5, or intervals therebetween, such as 20: 1-1: 3, 18: 1-1: 2, 15: 1-1: 1, 12: 1-2: 1, 10: 1-4: 1, 10: 1-6: 1, 10: 1-8: 1, 9: 1-8: 1.

In some embodiments, the crosslinking agent is selected from at least one of N, N' -methylenebisacrylamide, citric acid, boric acid, and borax. Preferably, the mass ratio of the cross-linking agent to the biogel is 1: 10-1: 50, specifically 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1: 32, 1: 33, 1: 34, 1: 35, 1: 36, 1: 37, 1: 38, 1: 39, 1:40, 1: 41, 1: 42, 1: 43, 1: 44, 1:45, 1: 46, 1: 47, 1: 48, 1: 49, 1:50, or a range therebetween, such as 1: 10-1: 45, 1: 15-1: 40, 1: 15-20: 40, 1: 48, 1: 49-20, 1:50, or a range therebetween, for example, 1: 10-1: 45, 1:40, 1:45, 1:40, 1: 48, 1: 20-1: 30.

In some embodiments, the acrylic monomer, the crosslinking agent, and the white carbon black are first mixed in water, and the mixture is then added to the biogel solution/dispersion. Preferably, the mixture is cooled in an ice-water bath and then added to the biogel solution/dispersion.

The temperature of the polymerization reaction can be controlled to be 65-80 ℃, and the time can be controlled to be 1-3 hours.

In some embodiments, the white carbon black is oil shale semi-coked white carbon black. The oil shale semicoke white carbon black can be prepared by the method comprising the following steps:

crushing and calcining the oil shale semi-coke;

and then soaking the calcined oil shale semi-coke with acid to obtain the oil shale semi-coke white carbon black.

In some embodiments, after the oil shale char is pulverized, it is passed through a 200 mesh screen and the screened powder is collected.

In some embodiments, the calcination temperature is controlled to be 800-900 ℃ for 2-3 hours.

In some embodiments, the oil shale semicoke is impregnated with sulfuric and/or nitric acid. Preferably, the oil shale semicoke is impregnated with a mixed acid consisting of sulfuric acid and nitric acid. More preferably, the oil shale semicoke is impregnated with a mixed acid consisting of sulfuric acid and nitric acid in a 1:1 molar ratio. The concentration of sulfuric acid in the mixed acid was 5 mol/L. After acid dipping treatment, washing and drying to obtain the oil shale semicoke-based white carbon black for later use.

In some embodiments, the immersion temperature is 90-100 ℃ and the time is 10-12 hours.

Examples

1 preparation of oil shale semicoke white carbon black

1.1, putting the industrial waste oil shale semicoke into a crusher to be crushed for 3-5 min, repeating for 3-5 times, and sieving by using a 200-mesh sieve to prepare the oil shale semicoke with the particle size of less than 200 meshes.

And 1.2, putting the screened oil shale semicoke into a tubular furnace for calcination at 800 ℃ for 2-3 hours.

1.3 putting 10g of calcined oil shale semi-coke into a 250mL beaker, pouring 50mL of 10mol/L concentrated sulfuric acid and 50mL of 10mol/L concentrated nitric acid respectively, putting into an oil bath pot, and rotationally stirring for 10-12 h at 90 ℃.

And 1.4, carrying out suction filtration on the oil shale semi-coke powder subjected to acid leaching, then washing for 5-8 times, and drying in a 60 ℃ blast drying oven for 20-24 hours to prepare the oil shale semi-coke based white carbon black for later use.

2 preparation of composite super absorbent resin

0.8g of Caesalpinia spinosa gum is put into 30mL of water, stirred and dispersed for 1-2 hours at 65-75 ℃ under 200-500 rmp to form a viscous uniform solution, an initiator (0.1 g of ammonium persulfate) is dissolved in 4mL of distilled water and then added dropwise, the temperature is kept for 10-20 min, and then the temperature is reduced to 50 ℃. And (2) cooling the functional monomer (7.2 g of acrylic acid), the cross-linking agent (0.02 g N' N-methylene bisacrylamide and 0.02g of boric acid) and a proper amount of oil shale semi-coked white carbon black for 30min in an ice-water bath environment, slowly adding the cooled functional monomer, the cross-linking agent and the oil shale semi-coked white carbon black into a biogel solution, heating to 75 ℃ for polymerization for 3h, placing the biogel solution in a 60 ℃ air blast drying oven for drying for 24h, and shearing to obtain the formed composite super absorbent resin.

FIG. 1 is an infrared spectrum of the composite super absorbent resin prepared by the present invention, wherein curve A is TG (Cassia nomame), curve B is oil shale semi-coke white carbon black, and curve C is the composite super absorbent resin. The absorption peak of the curve A at 1076 is the C-OH stretching vibration peak, the absorption peaks of the curve B at 1031 and 1093 are the Si-O stretching vibration peaks, and the peaks are obviously weakened or disappeared after the polymerization reaction, which indicates that the graft polymerization reaction of the oil shale semicoke-based white carbon black and the Caesalpinia spinosa gum is successful.

FIG. 2 is an SEM image of a composite super absorbent resin prepared by the present invention. Wherein, a is a composite super absorbent resin sample, and b is a blank sample without adding the oil shale semi-coked white carbon black. From the SEM picture, it can be observed that the blank sample without the oil shale semi-coke white carbon black is compact in surface, and after the oil shale semi-coke white carbon black is added, the surface of the water absorbent resin is relatively rough and the cross section thereof is relatively loose and has a plurality of porous structures, which indicates that the introduction of the oil shale semi-coke white carbon black affects the structure of the composite super absorbent resin, and it is possible that the addition of a proper amount of rigid oil shale semi-coke white carbon black can reduce the hydrogen bond interaction between the graft polymer chains, thereby effectively reducing the physical crosslinking degree between the polymer chains and increasing the water (salt) absorption ratio of the composite super absorbent resin.

FIG. 3 shows the water (salt) absorption performance of the composite super absorbent resin doped with different contents of oil shale semi-coked white carbon black. As can be seen from the figure, when the content of the oil shale semi-coke white carbon black is less than 2%, the water absorption capacity of the super absorbent resin tends to increase along with the increase of the content; when the content of the oil shale semi-coke white carbon black is equal to 2%, the water absorption capacity is the maximum (respectively reaching 625 g and 131 g/g in distilled water and 0.9% NaCl solution), and compared with the super absorbent resin without the oil shale semi-coke white carbon black, the water absorption capacity is improved by nearly 72%; when the content of the oil shale semicoke-based white carbon black is more than 2%, the water absorption capacity of the super absorbent resin begins to be reduced. The reason is that the introduction of a proper amount of rigid oil shale semi-coke white carbon black can reduce the hydrogen bond interaction between grafted polymer chains, thereby effectively reducing the physical crosslinking degree between the polymer chains and increasing the water absorption capacity of the resin.

As a novel high water absorption resin material, the water retention performance at different temperatures has great influence on the application of the high water absorption resin material in various fields. Therefore, the water retention properties of the composite super absorbent resin with the oil shale semi-coked white carbon content of 2% are shown in fig. 4 at Room Temperature (RT), 45 ℃ and 60 ℃. As can be seen from FIG. 4, the water retention rates of the fully swollen resin at room temperature, 45 ℃ and 60 ℃ are reduced along with the time, the water retention curve of the resin at room temperature is gentle than that at high temperature, and after 6 hours, the water retention rate of the resin still has 75%, the resin can retain water for 15 hours at 45 ℃ and can also reach 10 hours at 60 ℃, which shows that the composite super absorbent resin has good water retention performance.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A preparation method of a water absorbing material comprises the polymerization reaction of biological glue and acrylic monomers to generate the water absorbing material, and is characterized in that: and adding a certain amount of white carbon black into the polymerization reaction.

2. The preparation method according to claim 1, wherein the specific process of the preparation method comprises the following steps:

adding the biogel into water, uniformly mixing, and adding an initiator;

and adding acrylic monomers, a cross-linking agent and white carbon black, and then heating for reaction to generate the water absorbing material.

3. The production method according to claim 1 or 2, characterized in that: the biological gum is at least one of tarragon gum, artemisia glue, xanthan gum and guar gum.

4. The production method according to claim 1 or 2, characterized in that: the acrylic monomer is acrylic acid and/or acrylamide;

preferably, the mass ratio of the acrylic monomer to the biological glue is 20: 1-1: 5;

more preferably, the mass ratio of the acrylic monomer to the biological glue is 12: 1-2: 1;

most preferably, the mass ratio of the acrylic monomer to the biogel is 9: 1-8: 1.

5. The method of claim 2, wherein: the cross-linking agent is at least one of N, N' -methylene bisacrylamide, citric acid, boric acid and borax;

preferably, the mass ratio of the cross-linking agent to the biological glue is 1: 10-1: 50;

more preferably, the mass ratio of the cross-linking agent to the biogel is 1: 15-1: 40;

most preferably, the mass ratio of the cross-linking agent to the biogel is 1: 20-1: 30.

6. The method of claim 2, wherein: the initiator is ammonium persulfate and/or potassium persulfate;

preferably, the mass ratio of the initiator to the biogel is 1: 6-1: 12;

more preferably, the mass ratio of the initiator to the biogel is 1: 7-1: 10;

most preferably, the mass ratio of the initiator to the biogel is 1: 8-1: 9.

7. The method of claim 2, wherein: the reaction temperature is 65-80 ℃, and the reaction time is 1-3 hours.

8. The method of claim 1, wherein: the mass percentage content of the white carbon black in the water absorbing material is 1-6%;

preferably, the white carbon black is 1.5-3% by mass;

most preferably, the white carbon black is 2% by mass.

9. The production method according to any one of claims 1 to 8, characterized in that: the white carbon black is oil shale semi-coke based white carbon black, and preferably, the oil shale semi-coke based white carbon black is prepared by a method comprising the following steps:

crushing and calcining the oil shale semi-coke;

then soaking the calcined oil shale semi-coke with acid to obtain oil shale semi-coke white carbon black;

more preferably, after being crushed, the mixture is sieved by a 200-mesh sieve;

more preferably, the calcination temperature is 800-900 ℃ and the time is 2-3 hours;

more preferably, sulfuric and/or nitric acid impregnation is employed;

more preferably, the dipping temperature is 90-100 ℃ and the time is 10-12 hours.

10. A water-absorbing material characterized by: the water-absorbing material is prepared according to the preparation method of any one of claims 1 to 9.

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