BR102013003667A2 - SUPERABSorbent HYDROGELS COMPOSITE ACRYLAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING MINERAL CARBONATE CLASS - Google Patents

Abstract

SUPERABSORBENT HYDROGEN COMPOSITES OF ACRYLAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING MINERAL CARBONATE CLASSES. Superabsorbent hydrogels of acrylamide, acrylate or their copolymers (Pam Acril) and composites of these copolymers with mineral of the carbonate class (dolomite, calcite, aragonite, magnesite, ankerite, among others) were synthesized from polymerization reaction in solution via free radical . Potassium persulfate and N, N, N ', N'-tetramethylethylenediamine were used as initiator and accelerator, respectively, and N, N'-methylenebisacrylamide was the crosslinking agent, used in the concentration of 0.05 to 0.5% m / m (in relation to the total mass of the monometers). The mineral percentage was varied (5 to 50% w / w) in relation to the monometers, in order to obtain a series of superabsorbent composite hydrogels. The study of the effect of mineral concentration on water absorption of hydrogels was done by comparing the swelling kinetics of the composites, in distilled water, with that of Pam Acril. The results obtained show that the incorporation of mineral in the polymeric matrix increases the water absorption capacity of the materials. Considering that minerals are cheaper raw material than starting monometers, the hydrogel with the highest mineral content is the one with the lowest cost, and is therefore the most suitable for commercial production.

Description

“SUPERABSorbent HYDROGELS COMPOSITE OF ACRYLAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING MINERAL CARBONATE CLASS”

FIELD OF THE INVENTION The present invention relates to superabsorbent composite polymers of

water and aqueous solutions consisting of a copolymeric matrix of acrylamide and acrylates in which the particles of a carbonate class mineral are dispersed. The methodology described in this document is fast and economically viable, and will make it possible to synthesize fast-absorbing hydrogels for application in several 10 sectors, especially in agriculture, where these materials will act as soil conditioners, rapidly absorbing a large amount of water that will be gradually released to the plant as per your need.

BACKGROUND OF THE INVENTION

Superabsorbent hydrogels are materials made up of three-dimensionally cross-linked hydrophilic polymer networks capable of absorbing and retaining large volumes of water and aqueous solutions in their structure without dissolving (KABIRI et al., European Polymer Journal, 2003, 39, 1341).

The largest use of superabsorbent materials is for the manufacture of disposable toiletries such as women's pads and mainly diapers, which accounted for over 85% of the total superabsorbent material sold in 2002 (OHMURA, Nonwovens Industry, 2003, 34, 24). Another important application is in the agricultural sector, such as soil conditioners, where hydrogels need to have high water absorption capacity in a short time.

The main feature of a hydrogel is its ability to absorb water.

The degree of swelling, W (g water / g dry gel), is defined as the ratio of the swollen hydrogel mass to the dry hydrogel mass. The swelling of a hydrophilic polymer network occurs as a result of interactions between water molecules and hydrophilic groups attached to the network through hydrogen bonds. Hydrophilic groups present in the polymer network of hydrogels are hydrated in aqueous medium, and crosslinking prevents dissolution of hydrophilic polymer chains. When swollen, the polymeric networks are more elastic. The osmotic force that assists in driving the solvent into the polymer network is counterbalanced by a retracting elastic force. Thus, when the osmotic and elastic forces are equal, the hydrogel will have reached the state of swelling equilibrium 5 obtaining the maximum water absorption value (Weq) in a so-called equilibrium time (teq).

Superabsorbent hydrogels have been used as soil conditioners since the 1980s, motivated by significant improvements in soil properties. A soil conditioner is defined as any organic, synthetic, natural or chemically modified material that, added to the soil, favorably alters its physical and structural properties (KÃMPF and FERMINO, Genesis, Porto Alegre, 1999).

With the growth of the world population and the consequent increase in the demand for food production, it is necessary to create and apply new techniques that favor agricultural production combined with the preservation of natural resources, especially water.

Water is one of the main factors that influences the increase of crop productivity and, consequently, the increase of food production. A study by the United Nations Food and Agriculture Organization points out that 69% of the water used in the world (2,500 km3 / year) is directed to agricultural activity.

An alternative to solve the problem of water scarcity in the agricultural sector is the use of superabsorbent polymers, in the form of hydrogels, which allow the retention of a large amount of water and its subsequent release to the plant, providing a better use of water. .

In arid and semi-arid regions, such as much of northeastern territory, characterized by scarcity of surface water resources and high evapotranspiration, hydrogels absorb water supplied by irrigation and / or rain and gradually release it to plants. allowing the use of more spaced 30 watering shifts. In addition, they act to decrease the osmotic potential of saline soils due to their increased water availability. Superabsorbent polymers can further increase water storage capacity and reduce percolation losses in sandy soils, thereby increasing the efficiency of plant water and fertilizer use.

Among other benefits achieved with the use of hydrogels, we can highlight the reduction of irrigation frequency (reducing the costs of this activity), faster recovery of eroded, degraded soils from desertification areas, increased yields. of crops in semiarid regions, increased retention capacity of water and mobile nutrients by soil, and increased soil permeability and water infiltration.

Experiments developed with polyacrylamide and / or polyacrylate superabsorbent hydrogels show that these materials can improve the properties of dry soil for cultivation as they store a large amount of water, decreasing the frequency of plant irrigation and improving water retention. resulting in increased plant growth and performance (SHI et al., Scientia Horticulturae, 2010, 124,268).

The addition of hydrogel to sandy soil may prolong the survival of

seedlings subject to drought. HUTERMANN, ZOMMORO and REISE (Soil and Tillage Research, 1999, 50, 295) tested the application to the soil of a highly cross-linked polyacrylamide 40% hydrolysis commercial hydrogel (Stockosorb K-400). They observed that water retention increased exponentially with increasing amount of added hydrogel and that 0.4% hydrogel-treated seedlings survived twice as long as non-gel-treated seedlings.

Among the superabsorbents applied in agriculture, cross-linked polyacrylamides, polyacrylates or copolymers are responsible for most hydrogels, since in addition to having excellent hydrophilic properties, these materials still remain active in the soil for a long time (WANG and XIE, Journal of Polymer Research, 2009,16,143).

Polyacrylamides are not biologically degraded, so once applied to the soil, they are degraded or dissociated by cultivation, ultraviolet rays from the sun and continuous fractionation, around 10% per year. The final products of hydrogel dissociation are: CO2, H2O and NH3 (AZEVEDO, BERTONHA and GONÇALVES, Acta Scientiarum Agronomy, 2006, 28, 287). For the synthesis of superabsorbent hydrogels a variety of monomers are employed. Acrylic acid and its sodium or potassium salts, in addition to acrylamide, are the most frequently used in the industrial production of these materials, as is the case with hydrogels available in the Brazilian market: Luquasorb®, Hysorb®, Stockosorb® and Aquasorb®.

Luquasorb® and Hysorb® are produced by BASF Corporation. Hysorb® is a sodium polyacrylate used in disposable diapers which, according to the manufacturer, has a maximum absorption in deionized water and 0.9% NaCl solution of 550 and 50 g of water / g of dry hydrogel, respectively. Luquasorb® is a potassium polyacrylate-based hydrogel for agriculture which has the capacity to absorb up to 1000 g of deionized water / g of dry hydrogel, according to the manufacturer. Stockosorb® is a copolymer hydrogel for agricultural application produced by the German company Stockhausen GmbH Krefeld. It is made up of acrylamide acrylates, and has a maximum absorption capacity in deionized water of 300 g of water / g of dry hydrogel.

Aquasorb® hydrogel is a potassium acrylamide-acrylate copolymer produced by the French company SNF Floerger. It is a material for agricultural application and which, according to the manufacturer, can absorb up to 400 g of water / g of dry hydrogel when immersed in deionized water needing to remain in contact with water 20 longer than 240 minutes. According to the manufacturer, this material when used in soil could absorb a maximum of 150 g of water / g of dry hydrogel and remain active for more than 5 years.

In the world market there are currently over 100 trademarks of hydrogels and - despite all the benefits that can be obtained from the use of this product, Brazil does not use it in agriculture, due to the cost and the low availability in the national market, once which are all imported.

The development of a hydrogel with national technology will surely bring huge benefits. Furthermore, the product of the present invention is more efficient than those mentioned above, as it has a greater capacity to absorb water (up to 1200 g of water / g of dry hydrogel) in a short time, reaching swelling. maximum and balance in less than 8 minutes. There are some national technologies deposited with the National Institute of Industrial Property (INPI) for the production of hydrogels for the agricultural sector. As an example we can mention the product developed at the State University of Maringá (BR / PR), synthesized from acrylates, acrylamide and gum arabic. According to the inventors, a fast-absorbing hydrogel has been developed having a maximum absorption capacity of 300 g water / g dry hydrogel in just over an hour of immersion in distilled water (PI 0506316-7 A).

Another hydrogel also developed at the State University of Maringá (BR / PR) based on hydrolyzed acrylamide and modified cashew gum presents swelling degree 10 between 300 and 2000 g water / g dry hydrogel, depending on hydrolysis time, immersion in water and the concentration of cashew gum in the hydrogel. The maximum value of 2000 g water / g dry hydrogel was reached with a hydrolysis time of 4.5 hours requiring the hydrogel to remain immersed in distilled water for 35 hours (PI 0404265-4).

Superabsorbent polymer consisting of starch and polyvinyl alcohol was

developed for use in agriculture with an absorption capacity of 50 g water / g dry hydrogel in a distillation time of 2 weeks. According to the inventors, simulated soil tests show that this hydrogel is biodegraded within 180 days (PI 0904733-6 A2).

There are several technologies for the production of hydrogels aimed at the sector.

protected by patents filed with institutes / protection bodies in all parts of the world. These include hydrolysed polyacrylamide-based superabsorbent hydrogel which has an absorption capacity of 300 g of water / g of dry hydrogel over a 24 hour immersion time in distilled water (Fr 9104600). The development of composite hydrogels from polymeric matrices

reinforced with inorganic materials can not only offer an alternative to improve the mechanical and rheological properties of materials, but also provide high performance products at a viable cost by adding bulky fillers that are cheaper than pure polymer (WO 2004 / WO 30 2005/030279; US 3,935,363; JP 10-244249; US 5,489,469; US 4,500,670; US 4,454,055; US 6,124,391; US 5,419,956; US 6,175,055; US 2004018006 Al; US 6,376,011). Superabsorbent composite hydrogels obtained from inorganic materials such as kaolinite (WU, WEI and LIN, Polymer, 2003, 44, 6513), montmorillonite (BULUT et al., Journal of Hazardous Materials, 2009, 171, 717), attapulgite (WANG, ZHENG and WANG, Polymer Advanced and Technology, 5 2008, 19, 1852), diatomite (IQ et al., Polymer for Advanced Technology, 2007, 18, 184), vermiculite (ZHANG and WANG, Reactive and Functional Polymers, 2007, 67, 737), laponite (ZHANG et al., Biomaterials, 2009, 30, 1309), mica (LEE and TSAO, European Polymer Journal, 2005, 41, 1605), among others, show improvements in their mechanical properties and / or increased capacity. absorption rate of 10 water in relation to the hydrogel without mineral addition.

Researchers at the Federal University of Lavras (BR / MG) filed a patent for a composite hydrogel, consisting of the polysaccharide present in Magonia pubenscens integument and dehydrated argilomineral vermiculite, for water absorption and metal removal in aqueous solutions. This material has a maximum absorption capacity of 300 g water / g dry hydrogel when immersed in distilled water for 24 hours (PI 0705575-7 A2).

Researchers have developed at the Federal University of Rio de Janeiro (BR / RJ) cross-linked superabsorbent nanocomposites obtained from grafting cornstarch on acrylic acid added with a small amount of naturally sodium montmorillonite clay (MMTNa). All hydrogels obtained had a maximum absorption capacity of less than 500 g water / g dry hydrogel when immersed in distilled water and 30 g water / g dry hydrogel when in 0.9% NaCl solution (PI 0904295-4 A2 ).

There are no reports in the literature of the development of acrylamide-based composite hydrogels and carbonate-class mineral-containing acrylates, including dolomite. Therefore, there is no similar product offered to the market or patented that meets the requirements and properties of the hydrogel described in this document.

The incorporation of dolomite (or any other carbonate grade mineral) into the polymer matrix obtained from synthetic materials (acrylamide, acrylate and their copolymers) may enhance some of the original properties of the hydrogel or even provide the composite with new functionality, thus influencing the composite. their physical, chemical properties, and certainly in cost. Carbonates are a class of minerals that have in their formula

Λ

chemistry the ion CO3Carbonate sedimentary rocks (limestone and dolomites) are probably the most used mineral raw material in the industry. These rocks, consisting predominantly of the minerals calcite (CaCOs) and / or dolomite 5 (CaMg (C03) 2), are found on all continents. Brazil has an extensive geological reserve of these mineral goods (Brazilian Mineral Yearbook, National Department of National Production, Brazil, 2001).

Abundance, low cost and non-toxicity are some of the characteristics of carbonate class minerals, eg dolomite, which are favorable for their choice to obtain superabsorbent composite hydrogels. Developing hydrogels for soil applications using dolomite, for example, is a chemical, toxicological, ecologically and economically advantageous alternative.

DESCRIPTION OF THE FIGURES

The accompanying Figures mirror non-limiting examples, comprising a preferred embodiment of the process described therein using a carbonate class mineral, such as dolomite.

Figure 1 illustrates the system used in the hydrogel swelling study, called the immersion method, consisting of a 250 mL (A) glass becker and a 50 mL GOOCH crucible having a sintered glass filter plate with porosity 0 (160 to 250 microns) (B). The water level (C) and the swollen hydrogel (D) are also illustrated in the figure.

Figure 2 shows curves obtained from the swelling kinetics of the potassium acrylamide-acrylate copolymer hydrogel (Pam Acril) and the potassium acrylamide-acrylate composite hydrogel added with 20% dolomite 25 (DolG20). Swelling kinetics are performed from swelling degree (W) measurements as a function of immersion time of the hydrogel in distilled water using the system illustrated in Figure 1.

Figure 3 shows the variation of the degree of swelling in the equilibrium (Weq) of hydrogels with the concentration of dolomite mineral.

Figure 4 shows the variation in the degree of swelling in the balance.

(Weq) potassium acrylamide-acrylate copolymer hydrogel (Pam Acril) and potassium acrylamide-acrylate composite hydrogels with dolomite mineral content between 5 and 50% (DolG5, DolG10, DolGl5, DolG20, DolG30, DolG40, DolG50) in the different immersion media studied.

DETAILED DESCRIPTION OF THE INVENTION

The formulations to be described are only non-limiting examples of the invention, comprising a preferred embodiment of the process described therein, taking as an example carbonate mineral, dolomite. Preparation of Potassium Acrylate (KAc)

Potassium acrylate salt was prepared by neutralizing acrylic acid (Ac) under refrigeration and magnetic stirring with potassium hydroxide (KOH) to pH = 7.0.

Synthesis of acrylamide and / or potassium acrylate hydrogel (Pam Acril)

In a round bottom reactor was added 10 to 100 mL of distilled water, preferably 27 mL, between room temperature and 80 ° C under stirring and nitrogen gas flow. Then the acrylamide monomers (mass 15 0.5 to 5 g, preferably 1.05 g) and / or potassium acrylate in solution form (1 to 15 ml solution 1 to 6 mol / L, preferably 3 mL of 5 mol / L). After a few minutes, 5 to 50 mg of potassium persulphate initiator (KPS), preferably 16.2 mg, was added to the solution. Then, 2 to 20 mg of the crosslinker Ν, en'-methylenobisacrylamide (MBA), 20 preferably 9 mg, and between 10 and 200 μΕ of the reaction accelerator Ν, Ν, Ν ', Ν'tetramethylethylenediamine were added to the reaction mixture. (TEMED) at a concentration of 0.1 to 2 mol / L, preferably 50 μί of 0.6 mol / L. The system was closed and kept under stirring and N 2 flow until a firm gel formed.

After gel formation, the system was at rest for 1 to 48 h, better 24 h, to complete the reaction. The resulting gel was removed from the system, cut into small pieces and washed with distilled water to remove solubles. The obtained material was oven dried at 40 to 80 ° C, better 70 ° C, macerated and separated by particle size.

Synthesis of the potassium acrylamide-dolomite acrylate (DolG) composites

In the synthesis of the DolG series, the same conditions used for

Pam Acril, namely: the total volume of water and the amounts of acrylamide, acrylate, KPS, TEMED and MBA. The methodology was also the same employed for Pam Acril, except that the monomers were dissolved in a dispersion of the mineral in water. The concentration of dolomite in the copolymer ranged from 5 to 50% w / w in relation to the monomers, obtaining the following series of materials: 5 DolG5; DolG10; DolG15; DolG20; DolG30, DolG40 and DolG50 corresponding respectively to 5; 10; 15; 20; 30, 40 and 50% by weight of dolomite in relation to the mass of monomers.

Swelling of hydrogels in distilled water

The hydrophilic properties of hydrogels were studied from 10 measurements of the degree of swelling (W) as a function of immersion time in distilled water. In a pre-moistened 50mL (porosity # 0) filter crucible and with the dry outer wall was placed approximately 20 mg of hydrogel with 24-35 mesh size. This set was immersed in water so that the gel was completely submerged. The crucible / gel set was removed at various time intervals, the outer crucible wall dried and the system weighed on an analytical balance. Each experiment was performed in triplicate. Figure 1 illustrates the system used, called the immersion method.

From equation 1, where Wt is the water mass gain per gram of dry gel at a given time t, mt the mass of the swollen material and t the mass of the initial dry material, it was possible to perform the swelling kinetics in all immersion media studied.

Wt = (mt-mo / mo) (1)

The effect of incorporation of dolomite mineral in the potassium acrylamide-acrylate copolymer matrix was evaluated from the hydrogels swelling kinetics in distilled water, where the water absorption capacity of the copolymer with and without mineral was compared, as well as the effect caused by the gradual increase of dolomite concentration in the swelling capacity of hydrogels.

Figure 2 shows the effect of the 20% increase in dolomite on the copolymer's water absorption capacity by comparing the swelling kinetics of the composite (DolG20) with that of the mineral-free hydrogel (Pam Acril). The curves obtained from swelling kinetics for the synthesized hydrogels are similar, showing a rapid initial absorption followed by an equilibrium threshold (Weq) 5 whose value depends on the gel, as exemplified in Figure 2.

For gels that have dolomite, weq increase with increasing the amount of mineral up to 10% concentration. After that, there is a decrease in the water absorption capacity of the composites, as shown in Figure 3. Hydrogels with 5 to 20% dolomite have the highest Weq values. Table 1 shows some characteristics of the gels, obtained through the swelling curves, where teq is the time required to reach equilibrium.

Table 1. Parameters obtained from distilled water swelling kinetics for hydrogels with cross-linking degree 0.33% w / w.

Hydrogel Weq (g water / g dry gel) teq (min) Weq (DolG) / Weq (Pam Acril) Pam Acril 731 ± 37 6.1 DolG5 1183 ± 45 7.1 1.62 DolG10 1195 ± 70 7, 8 1.63 DolGl 5 1120 ± 11 8.6 1.53 DolG20 1109 ± 40 6.5 1.52 DolG30 924 ± 46 10.6 1.26 DolG40 838 ± 90 11.4 1.15 DolG50 738 ± 91 13 .5 1.00 All synthesized hydrogels are characterized as superabsorbents because they have Weq greater than 100 g water / g dry gel (OMIDIAN, ROCCA and PARK, Journal of Controlled Release, 2005, 102, 3). All synthesized gels have a low teq value, indicating a fast absorption rate, as high Weq values are reached within a few minutes.

The increase in Weq value for DolG10 is 63% over the Weq for gel without dolomite. Dolomite acts on the gel as a support between polymer chains, increasing the amount of material charge and the hydrophilicity of the composite. Another achievement is the increase in crosslinking caused by the presence of the mineral, which causes a decrease in gel elasticity and water absorption capacity. Both effects occur simultaneously. Up to 10% dolomite increase in hydrophilicity prevails. From then on, cross-linking gradually becomes more important, causing a decrease in Weq, well characterized in gels with 30, 40 and 50% mineral.

Swelling of hydrogels in saline solutions

It has been confirmed through theoretical and experimental considerations that the presence of ions has a great effect on the swelling of hydrogels. The balance between the osmotic pressure of the system and the elastic response of the gel is one of the factors controlling water absorption capacity. Osmotic pressure results from the difference between the concentration of ions inside the gel and the concentration of ions in the external solution (BAJPAI and GIRI, Reactive and Functional Polymers, 2002, 53,125).

Disregarding ion-ion, ion-solvent and ion-polymer interactions, the pressure

osmotic is given by: Jijon = RTZ (Cig - Cis) (2)

where C is the concentration of mobile ions of the species “i”, while “g” and “s” represent the gel and solution, respectively. This means that the greater the difference between the ionic concentration of the gel and the solution, the greater will be Weq.

The effect of the presence of ions on the water absorption capacity of

Hydrogels were tested by the individual addition of alkali and alkaline earth metal chlorides, all at a concentration of 0.001 mol / L and the results are shown in Table 3. Swelling was performed using the same procedure adopted for distilled water testing.

Table 3. Example of Weq (g water / g dry gel) obtained for 0.33% w / w cross-linked hydrogels in different saline solutions at 0.001 mol / l.

Weq Hydrogel (g water / g dry gel) NaCl KCl CaCl2 Pam Acryl 517 ± 4.1 486 ± 2.3 117 ± 3.8 DolG5 664 ± 0.6 632 ± 3.5 134 ± 1.4 DolG10 649 ± 0.8 658 ± 12 137 ± 3.7 DolGl 5 680 db 16 648 ± 4.3 158 ± 4.5 DolG20 616 ± 5.5 605 ± 21 149 ± 2.0 DolG30 496 ± 8.0 496 ± 3 , 2 130 ± 9.6 DolG40 457 ± 8.5 457 ± 2.4 94 ± 4.3 DolG50 437 ± 8.0 420 ± 15 122 ± 1.0 The values indicate that the gel without mineral is less influenced by presence of salts than composites, showing a lower loss of absorption capacity with the change of the immersion medium (from water to saline solutions). However, hydrogels that have between 5 and 20% dolomite have the highest Weq values in any of the immersion media studied.

Divalent and trivalent metals can dramatically decrease the swelling capacity of hydrogels. This is due to the ability of complexation of carboxamide or carboxylate groups and formation of inter and intra molecular complexes, thus justifying the low Weq values obtained in CaCl2 solution. DolGl5 and DolG20 performed best.

Figure 4 shows the effect of dolomite content on maximum swelling in the various immersion media studied. There is no significant variation in Weq with dolomite percentage between 5 and 20% in all studied media. It is also noted that there was a substantial improvement in the water absorption capacity of hydrogels by the effect of mineral addition (DolG5 to DolG20). When 30, 40 or 50% of the mineral is added the absorption decreases greatly, being inferior to the hydrogel without mineral, in some immersion media.

The results indicate that hydrogels with 0.33% w / w crosslinking containing dolomite, especially those between 5 and 20% of mineral, 20 have water absorption characteristics suitable for use as soil superabsorbents. Considering that dolomite is a cheaper raw material than the starting monomers, that hydrogel with higher dolomite content (20%), among those with higher Weq, lower teq and lower saline effect on the amount of water absorbed. , is the one that will present the lowest cost and is therefore the 25 most suitable for commercial production.

In relation to all the above, including the state of the art, it can be said that the product described in this document has many advantages, such as: national technology; quick and simple synthesis; pioneering use of dolomite mineral in hydrogels; economic viability; fast water superabsorption.

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Claims (20)

1. “COMPOSITE SUPERABSorbent HYDROGELS OF ACRILAMIDE, ACCILYLES AND THEIR COPOLYMERS CONTAINING MINERAL CLASS OF CARBONATES”, characterized in that they are composed of acrylamide, acrylates or their copolymers containing minerals belonging to the class of carbonates (dolomite, magnesite, calcite, magnesite, carbonite among others), presenting fast superabsorption properties, and can absorb up to 1200 g of water / g of hydrogel in less than 8 minutes. 2. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRILAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS" according to claim 1, characterized by the presence of acrylamide, acrylates and their copolymers by means of a polymerization reaction in a polymerization reaction (using distilled water as solvent) in the presence of a crosslinking agent and using oxide reduction reaction as the initiating system. 3. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS" according to claims 1 and 2, characterized in that the polymeric matrix may be obtained by acrylamide, acrylate or by admixture of acrylate , acrylic acid and acrylates in any proportions. 4. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS" according to claim 1, characterized in that the use of potassium acrylate obtained from the total neutralization of acrylic acid is preferred. potassium hydroxide base. 5. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES AND THEIR CARBONATE-CLASS MINERAL COPOLYMERS" according to Claims 1 and 2, characterized by the use of a cross-linking agent, preferably o, Ν'-methylenobisacryl (MB) at a concentration of 0.05 to 0.5% w / w relative to total monomer mass. 6. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES AND THEIR CARBONATE-CONTAINING MINERAL COPOLYMERS" according to claims 1 and 2, characterized in that a redox initiation system, preferably potassium persulfate, is used to obtain it. KPS) and a nitrogenous base as a reaction accelerator, preferably Ν, Ν, Ν ', Ν'-tetramethylethylenediamine (TEMED). 7. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR CARBONATE-CONTAINING MINERAL COPOLYMERS" according to claims 1 and 2, characterized in that the copolymerization reaction with the presence of the nitrogenous base occurs at room temperature and in the absence thereof at 40 to 80 ° C, preferably to 60 ° C. 8. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS", according to claims 1, 2 and 3, characterized in that the monomers are added to a mineral dispersion obtained by the mixture. of a mineral of the carbonate class to water, in particular dolomite and calcite minerals (individually or a mixture thereof), among others, without restriction. 9. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRILAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS", according to claim 7, characterized by the incorporation into the polymer matrix of a carbonate class mineral, in particular, of dolomite mineral concentration of 0.1 to 50% w / w, relative to the total monomer mass. 10. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS", according to claim 9, characterized in that the incorporated mineral is a low cost and highly available raw material. in Brazil. 11. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS" according to claims 1 to 10, characterized in that the materials obtained are rapidly overabsorbing hydrogels and may absorb up to 1200 g of water / g hydrogel dried in a short time, reaching maximum swelling and balance in less than 8 minutes. 12. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING MINERAL CARBONATE CLASS" according to claim 11, characterized by the use of hydrogels obtained in the agricultural sector as soil conditioner, water absorber / storage system controlled / prolonged release of water, preservative of soil moisture, among others, without restricting. 13. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES AND THEIR CARBONATE-CONTAINING MINERAL COPOLYMERS" according to claim 12, characterized in that the hydrogels obtained in agriculture are applied as a carrier / vehicle for controlled / extended release agricultural inputs, such as: fertilizers, growth agents, pesticides, herbicides, fungicides, any active agent that promotes increased agricultural productivity, among others, without restricting. 14. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR CARBONATE-CONTAINING MINERAL COPOLYMERS" according to claim 11, characterized by the use of hydrogels obtained in the manufacture of disposable sanitary napkins such as: intimate absorbents and diapers , among others, without restricting. 15. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS", according to claim 11, characterized by the use in the biomedical area as bandages and surgical buffers, without restricting skin dressings. 16. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS", according to claim 11, characterized by their use as a vehicle for drugs, skin therapeutic agents, cosmetic agents, active ingredient delivery agents skin, among others, without restricting. 17. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRILAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING THE CARBONATE CLASS" according to claim 11, characterized by the use as an adsorbing element of metals, ions, organic compounds, among others, without restriction. 18. "COMPOSITE SUPERABSIVE HYDROGELS OF ACRILAMIDE, ACRYLATES, AND THEIR CARBONATE-CONTAINING MINERAL COPOLYMERS" according to claim 17, characterized by their use for industrial effluent decontamination procedures, waters contaminated with agricultural inputs, among others, without restricting. 19. "COMPOSITE SUPERABSorbent HYDROGELS OF ACRYLAMIDE, ACRYLATES, AND THEIR COPOLYMERS CONTAINING MINERAL CARBONATE CLASS" according to claim 17, characterized by use as a filter element to prevent contamination of surface water and groundwater. 20. “SUPERABSorbent HYDROGELS COMPOSITE ACRYLAMIDE, ACRYLATES AND THEIR COPOLYMERS CONTAINING MINERAL CARBONATE CLASS”, characterized in that they can be used in any application for which a superabsorbent hydrogel is intended.