Method for preparing water-absorbing resin based on acidic zeolite molecular sieve

Abstract

This invention relates to the field of resin preparation, specifically a method for preparing a water-absorbing resin based on acidic zeolite molecular sieves. The method includes mixing corn starch and water at a specific mass ratio, heating and stirring to form a stable foam; dispersing the acidic zeolite molecular sieve within the foam and cooling to form a solid foam framework containing dispersed zeolite; preparing a monomer solution; and injecting the monomer solution dropwise into the solid foam framework to initiate a polymerization reaction, forming a gel-like polymer. The gel-like polymer is then heated and maintained at this temperature for a period of time to undergo a secondary polymerization reaction. A post-curing reaction is then carried out at a temperature range of 70°C to 95°C until a highly cross-linked composite with a three-dimensional network of acidic zeolite and water-absorbing resin is formed. The composite is then freeze-dried, and the dried product is ground and sieved to obtain composite particles. This invention achieves a high zeolite loading and improves the adsorption performance of the material.

Description

Technical Field

[0001] This invention relates to the field of resin preparation, and more specifically, to a method for preparing water-absorbing resins based on acidic zeolite molecular sieves. Background Technology

[0002] Superabsorbent resin (SAR), a polymer material capable of absorbing and retaining large amounts of water, is widely used in disposable absorbent products such as diapers and sanitary napkins. Its main function is to efficiently absorb bodily fluids, providing a dry and comfortable user experience. However, SAR alone exhibits inherent limitations when dealing with complex bodily fluid components, especially in handling odor molecules such as ammonia and hydrogen sulfide present in urine, as well as potential bacterial growth.

[0003] To overcome the shortcomings of superabsorbent polymers in odor adsorption and antibacterial properties, combining superabsorbent polymers with inorganic materials possessing specific functions has become an important research direction. Zeolite molecular sieves, as a type of aluminosilicate with a regular pore structure and unique ion exchange / adsorption properties, have attracted much attention due to their excellent adsorption capacity for small molecules such as ammonia. In particular, acidic zeolite molecular sieves, with their abundant Brønsted acid sites and / or Lewis acid sites on their surface, have advantages in adsorbing alkaline substances and catalytically converting odor molecules.

[0004] The aim of compounding acidic zeolite molecular sieves with water-absorbing resins is to obtain composite materials that combine high-efficiency water absorption with odor adsorption / control capabilities. However, traditional compounding methods face numerous technical challenges and limitations.

[0005] Physical blending is the simplest compounding method, which involves directly mixing zeolite molecular sieve powder with water-absorbing resin powder. This method is easy to operate, but it usually faces the following problems:

[0006] Uneven dispersion: The zeolite molecular sieve and the water-absorbing resin have large differences in density, particle size and surface properties, which makes it easy for agglomeration to occur during mixing. The zeolite is not evenly dispersed, which limits the exposure and utilization efficiency of its functional sites.

[0007] Poor interfacial bonding: The lack of effective chemical or physical bonding between zeolite and polymer leads to poor interfacial stability. When zeolite absorbs water and expands or is subjected to pressure, zeolite particles are easily detached from the polymer matrix, affecting the structural integrity and long-term performance of the composite material.

[0008] Low functional synergy: Due to uneven dispersion and poor interfacial bonding, the adsorption sites of zeolite may be wrapped or blocked by the polymer matrix, making it difficult to fully exert its adsorption and ion exchange functions, resulting in limited improvement in the overall performance of the composite material.

[0009] Traditional in-situ polymerization typically involves directly adding zeolite molecular sieves during the polymerization of superabsorbent resin monomers. While this improves dispersibility to some extent, the following problems still exist:

[0010] Zeolites are prone to sedimentation or agglomeration: In liquid-phase polymerization systems, especially when the polymerization reaction is slow or the stirring is insufficient, zeolite particles with a higher specific gravity are still prone to sedimentation or agglomeration, making it difficult to form a highly uniform composite structure.

[0011] Polymer coverage of active sites: During polymerization, the growth of polymer chains may non-selectively coat the active sites on the zeolite surface, reducing its effective adsorption area and utilization efficiency.

[0012] Uncontrollable pore structure: The pore structure of the final composite material is mainly determined by the polymer polymerization process. There is a lack of precise control over the microenvironment and channel structure around the zeolite, which is not conducive to the rapid diffusion and adsorption of target molecules (such as odor molecules).

[0013] Therefore, developing a novel preparation method that can effectively address the issues of uniform dispersion of zeolite molecular sieves, enhance interfacial bonding, and precisely control the microstructure of composite materials, in order to maximize the synergistic effect of acidic zeolite and absorbent resin, is a pressing technical challenge that needs to be solved in the field of absorbent products such as absorbent diapers. Summary of the Invention

[0014] Therefore, the purpose of this invention is to provide a method for preparing a water-absorbing resin based on acidic zeolite molecular sieves, which can achieve a high zeolite loading, and at the same time, the zeolite molecular sieve particles can be fully dispersed during the formation of foam template to improve the adsorption performance of the material.

[0015] To achieve the above objectives, the present invention provides the following technical solution:

[0016] The preparation method of water-absorbing resin based on acidic zeolite molecular sieves includes the following steps:

[0017] S1. Pre-fabrication of natural polysaccharide-based foam templates and zeolite embedding:

[0018] Mix corn starch and water at a mass ratio of 1:8 to 1:15, heat to 70℃ to 95℃ and stir to form a stable foam.

[0019] Acidic zeolite molecular sieves are dispersed in the foam and cooled to 0°C~10°C to form a solid foam skeleton containing dispersed zeolite.

[0020] S2, Monomer solution permeation and segmented in-situ polymerization:

[0021] Prepare a monomer solution containing a water-absorbing monomer, a crosslinking agent, and an initiator;

[0022] The monomer solution is injected dropwise into the solid foam skeleton in 2-4 portions. After each injection, a polymerization reaction is carried out at a temperature range of 20℃-50℃, with each stage of polymerization lasting 30-90 minutes, forming a gel-like polymer.

[0023] S3, Temperature Curing, Structure Release and Crosslinking:

[0024] The gel-like polymer obtained in step S2 is heated to 60℃~90℃ at a heating rate of 1℃ / min~3℃ / min and held within this temperature range for a period of time to carry out a secondary polymerization reaction, while the foam phantom degrades to release the channel structure.

[0025] Continue the post-curing reaction within a temperature range of 70℃ to 95℃ until a highly cross-linked composite with an acidic zeolite-water-absorbing resin three-dimensional network is formed.

[0026] S4. Freeze-drying and post-processing:

[0027] The composite obtained in step S3 was freeze-dried at a temperature range of -70℃ to -40℃ for 24 to 72 hours.

[0028] The dried product is ground and sieved through a 100-200 mesh screen to obtain composite particles.

[0029] The present invention is further configured as follows: In step S1, corn starch and water are first mixed at a mass ratio of 1:8 to 1:15, placed in a reaction vessel equipped with a mechanical stirrer, and stirred at 100 to 300 rpm for 10 to 20 minutes at 25°C until a uniformly dispersed starch slurry is formed.

[0030] The starch slurry is then heated at 70°C to 95°C while being sheared and stirred at 500 to 800 rpm for 15 to 20 minutes until an initial foam with an average pore size of 50 to 100 micrometers is formed.

[0031] During this process, Tween-80 surfactant, with a total mass percentage of 0.01~0.1%, is added in two equal portions. The first portion is added after stirring for 5 minutes, and the second portion is added after stirring for 10 minutes.

[0032] The present invention is further configured such that the acidic zeolite molecular sieve is of type ZSM-5, with a Si / Al molar ratio of 1600±20 and an average particle size of 120nm.

[0033] The present invention is further configured such that, in step S1, the acidic zeolite molecular sieve, when dispersed in the foam, has a mass fraction of 15-20%;

[0034] The zeolite molecular sieve is ultrasonically dispersed at 200-300W for 20-35 minutes before dispersion, and then centrifuged at 1800-2500rpm for 8-15 minutes.

[0035] The present invention is further configured such that: in step S1, the zeolite suspension is slowly added to the foam body by a syringe pump at a rate of 0.15 mL / min to 0.5 mL / min, while stirring at a low speed of 50 rpm to 100 rpm for 5 to 20 minutes, and then the foam body containing zeolite is rapidly cooled to 0°C and kept there for 2 to 4 hours.

[0036] The present invention is further configured such that, in step S2, the components of the monomer solution, by total mass percentage, are: 60%~75% acrylic acid, 20%~25% acrylamide, 0.3%~0.4% N,N'-methylenebisacrylamide crosslinking agent, 0.05%~0.08% potassium persulfate initiator, and 0.01%~0.02% N,N,N',N'-tetramethylethylenediamine co-initiator, with the balance being deionized water.

[0037] The present invention is further configured such that: after the monomer solution is prepared, it is subjected to vacuum degassing for 20 to 40 minutes to remove dissolved oxygen.

[0038] The present invention is further configured such that: in step S2, after each monomer injection, the solid foam skeleton is under a slightly positive pressure nitrogen atmosphere with a pressure of 0.03MPa~0.07MPa.

[0039] The present invention is further configured such that: in step S3, microwave-assisted crosslinking is introduced during the heating stage of the secondary polymerization reaction, the microwave power is 200W~400W, and the irradiation time is 2 minutes~6 minutes; the post-curing reaction is maintained at a temperature range of 75℃~85℃ for 2~4 hours.

[0040] Compared with the shortcomings of the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention achieves a high zeolite loading by in-situ introducing and immobilizing zeolite particles within a natural polysaccharide foam template. Simultaneously, the zeolite particles are sufficiently dispersed during foam template formation, avoiding the zeolite agglomeration problem common in traditional mechanical mixing methods. Uniformly dispersed zeolite particles can more effectively utilize their adsorption active sites, significantly improving the material's adsorption performance.

[0042] The composite material combines the excellent adsorption properties of zeolite with the high water absorption capacity of superabsorbent resin. The porous structure provides abundant transport channels and reaction sites, while the high zeolite loading and good dispersibility ensure efficient adsorption, and the superabsorbent resin imparts significant water absorption and swelling capacity. Therefore, the composite material of this invention exhibits a synergistic enhancement effect in adsorbing target pollutants (such as ammonia nitrogen and heavy metal ions) and absorbing water, demonstrating superior overall performance compared to single zeolite or superabsorbent resins. Attached Figure Description

[0043] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0044] Reference Figure 1 The following embodiments of the preparation method of the water-absorbing resin based on acidic zeolite molecular sieves of the present invention are further described, including the following steps:

[0045] Example 1:

[0046] Step S1, Pre-fabrication of natural polysaccharide-based foam template and embedding of zeolite: Mix 10g of corn starch and 100g of water at a mass ratio of 1:10, place them in a reaction vessel equipped with a mechanical stirrer, and stir at 200rpm for 15 minutes at 25℃ until a uniformly dispersed starch slurry is formed.

[0047] The starch slurry was then heated at 80°C while being sheared and stirred at 600 rpm for 18 minutes until an initial foam with an average pore size of 70 micrometers was formed. During this process, 0.05% of Tween-80 surfactant was added twice in equal amounts: the first addition was after stirring for 5 minutes, and the second addition was after stirring for 10 minutes.

[0048] ZSM-5 type acidic zeolite molecular sieve (Si / Al molar ratio of 1600, average particle size of 120 nm) was dispersed in the foam, with a mass fraction of 18%. The zeolite molecular sieve was ultrasonically dispersed at 250 W for 30 minutes before dispersion and then centrifuged at 2000 rpm for 10 minutes.

[0049] The zeolite suspension was slowly added to the foam at a rate of 0.3 mL / min using a syringe pump, while stirring at a low speed of 80 rpm for 10 minutes. The foam containing zeolite was then rapidly cooled to 0°C and kept there for 3 hours to form a solid foam skeleton containing dispersed zeolite.

[0050] Step S2, Monomer Solution Infiltration and Segmented In-situ Polymerization: Prepare a monomer solution containing acrylic acid, acrylamide, N,N'-methylenebisacrylamide crosslinking agent, potassium persulfate initiator, and N,N,N',N'-tetramethylethylenediamine co-initiator. The monomer solution components, by total mass percentage, are: acrylic acid 65%, acrylamide 23%, N,N'-methylenebisacrylamide 0.35%, potassium persulfate 0.06%, N,N,N',N'-tetramethylethylenediamine 0.015%, with the balance being deionized water. After the monomer solution is prepared, it is subjected to vacuum degassing for 30 minutes to remove dissolved oxygen.

[0051] The monomer solution was injected dropwise into the solid foam skeleton in three equal portions. After each injection, the solid foam skeleton was placed under a slightly positive pressure nitrogen atmosphere at a pressure of 0.05 MPa and subjected to a polymerization reaction at 35°C. Each stage of the polymerization reaction lasted for 60 minutes, forming a gel-like polymer.

[0052] Step S3, Heating and Curing, Structure Release and Crosslinking: The gel polymer obtained in step S2 is heated to 70°C at a heating rate of 2°C / min and maintained at this temperature for 30 minutes to carry out a secondary polymerization reaction. Microwave-assisted crosslinking is introduced during this heating stage, with a microwave power of 300W and an irradiation time of 4 minutes.

[0053] The post-curing reaction continued at 80°C for 3 hours until a highly cross-linked composite with an acidic zeolite-water-absorbing resin three-dimensional network was formed. During this process, the corn starch foam phantom degraded, releasing its channel structure.

[0054] Step S4, Freeze-drying and Post-treatment: The composite obtained in step S3 is freeze-dried at -60°C for 48 hours. The dried product is then ground and sieved through a 150-mesh sieve to obtain composite particles.

[0055] Example 2:

[0056] Step S1, Pre-fabrication of natural polysaccharide-based foam template and embedding of zeolite: Mix 10g of corn starch and 80g of water at a mass ratio of 1:8, place them in a reaction vessel equipped with a mechanical stirrer, and stir at 150rpm for 10 minutes at 25℃ until a uniformly dispersed starch slurry is formed.

[0057] The starch slurry was then heated at 70°C while being sheared and stirred at 500 rpm for 15 minutes until an initial foam with an average pore size of 50 micrometers was formed. During this process, 0.01% of Tween-80 surfactant was added twice in equal amounts: the first addition was after stirring for 5 minutes, and the second addition was after stirring for 10 minutes.

[0058] ZSM-5 type acidic zeolite molecular sieve (Si / Al molar ratio of 1600, average particle size of 120 nm) was dispersed in the foam body at a mass fraction of 15%. The zeolite molecular sieve was ultrasonically dispersed at 200 W for 20 minutes before dispersion and then centrifuged at 1800 rpm for 8 minutes.

[0059] The zeolite suspension was slowly added to the foam at a rate of 0.15 mL / min using a syringe pump, while stirring at a low speed of 50 rpm for 5 minutes. The foam containing zeolite was then rapidly cooled to 0°C and kept there for 2 hours to form a solid foam skeleton containing dispersed zeolite.

[0060] Step S2, Monomer Solution Infiltration and Segmented In-situ Polymerization: Prepare a monomer solution containing acrylic acid, acrylamide, N,N'-methylenebisacrylamide crosslinking agent, potassium persulfate initiator, and N,N,N',N'-tetramethylethylenediamine co-initiator. The monomer solution components, by total mass percentage, are: acrylic acid 60%, acrylamide 25%, N,N'-methylenebisacrylamide 0.3%, potassium persulfate 0.05%, N,N,N',N'-tetramethylethylenediamine 0.01%, with the balance being deionized water. After the monomer solution is prepared, it is subjected to vacuum degassing for 20 minutes to remove dissolved oxygen.

[0061] The monomer solution was injected dropwise into the solid foam skeleton in two equal portions. After each injection, the solid foam skeleton was placed under a slightly positive pressure nitrogen atmosphere at a pressure of 0.03 MPa and subjected to a polymerization reaction at a temperature of 20°C. Each stage of the polymerization reaction lasted for 30 minutes, forming a gel-like polymer.

[0062] Step S3, Heating and Curing, Structure Release and Crosslinking: The gel polymer obtained in step S2 is heated to 60°C at a heating rate of 1°C / min and held at this temperature for 30 minutes to carry out a secondary polymerization reaction. Microwave-assisted crosslinking is introduced during this heating stage, with a microwave power of 200W and an irradiation time of 2 minutes.

[0063] The post-curing reaction continued at 75°C for 2 hours until a highly cross-linked composite with an acidic zeolite-water-absorbing resin three-dimensional network was formed. During this process, the corn starch foam phantom degraded, releasing its channel structure.

[0064] Step S4, Freeze-drying and Post-treatment: The composite obtained in step S3 is freeze-dried at -70°C for 24 hours. The dried product is then ground and sieved through a 100-mesh sieve to obtain composite particles.

[0065] Example 3:

[0066] Step S1, Pre-fabrication of natural polysaccharide-based foam template and embedding of zeolite: Mix 10g of corn starch and 150g of water at a mass ratio of 1:15, place them in a reaction vessel equipped with a mechanical stirrer, and stir at 300rpm for 20 minutes at 25℃ until a uniformly dispersed starch slurry is formed.

[0067] The starch slurry was then heated at 95°C while being sheared and stirred at 800 rpm for 20 minutes until an initial foam with an average pore size of 100 micrometers was formed. During this process, 0.1% of Tween-80 surfactant was added twice in equal amounts: the first addition was after stirring for 5 minutes, and the second addition was after stirring for 10 minutes.

[0068] ZSM-5 type acidic zeolite molecular sieve (Si / Al molar ratio of 1600, average particle size of 120 nm) was dispersed in the foam body at a mass fraction of 20%. The zeolite molecular sieve was ultrasonically dispersed at 300 W for 35 minutes before dispersion and then centrifuged at 2500 rpm for 15 minutes.

[0069] The zeolite suspension was slowly added to the foam at a rate of 0.5 mL / min using a syringe pump, while stirring at a low speed of 100 rpm for 20 minutes. The foam containing zeolite was then rapidly cooled to 0°C and kept there for 4 hours to form a solid foam skeleton containing dispersed zeolite.

[0070] Step S2, Monomer Solution Infiltration and Segmented In-situ Polymerization: Prepare a monomer solution containing acrylic acid, acrylamide, N,N'-methylenebisacrylamide crosslinking agent, potassium persulfate initiator, and N,N,N',N'-tetramethylethylenediamine co-initiator. The monomer solution components, by total mass percentage, are: acrylic acid 75%, acrylamide 20%, N,N'-methylenebisacrylamide 0.4%, potassium persulfate 0.08%, N,N,N',N'-tetramethylethylenediamine 0.02%, with the balance being deionized water. After the monomer solution is prepared, it is subjected to vacuum degassing for 40 minutes to remove dissolved oxygen.

[0071] The monomer solution was injected dropwise into the solid foam skeleton in four equal portions. After each injection, the solid foam skeleton was placed under a slightly positive pressure nitrogen atmosphere at a pressure of 0.07 MPa and subjected to a polymerization reaction at a temperature of 50°C. Each stage of the polymerization reaction lasted for 90 minutes, forming a gel-like polymer.

[0072] Step S3, Heating and Curing, Structure Release and Crosslinking: The gel polymer obtained in step S2 is heated to 90°C at a heating rate of 3°C / min and maintained at this temperature for 30 minutes to carry out a secondary polymerization reaction. Microwave-assisted crosslinking is introduced during this heating stage, with a microwave power of 400W and an irradiation time of 6 minutes.

[0073] The post-curing reaction continued at 85°C for 4 hours until a highly cross-linked composite with an acidic zeolite-water-absorbing resin three-dimensional network was formed. During this process, the corn starch foam phantom degraded, releasing its channel structure.

[0074] Step S4, Freeze-drying and Post-treatment: The composite obtained in step S3 is freeze-dried at -40°C for 72 hours. The dried product is then ground and sieved through a 200-mesh sieve to obtain composite particles.

[0075] Based on Examples 1-3, the following test table 1 is prepared:

[0076]

[0077] Comparative Example 1: No zeolite embedding

[0078] This comparative example omits the zeolite embedding process in step S1, i.e., the acidic zeolite molecular sieve is not dispersed in the foam. The operating conditions for the remaining steps S1 (pre-fabrication of natural polysaccharide-based foam template), S2, S3, and S4 are the same as in Example 1. The resulting product is a zeolite-free water-absorbing resin.

[0079] Comparative Example 2: In-situ polymerization without segmentation

[0080] In this comparative example, the monomer solution in step S2 is injected into the solid foam skeleton in one step, and a one-time polymerization reaction is carried out at a temperature of 35°C for a reaction time of 180 minutes (equal to the total time of segmented polymerization in Example 1, which is 3 * 60 minutes). The operating conditions for the remaining steps S1, S3, and S4 are the same as in Example 1.

[0081] Comparative Example 3: No microwave-assisted crosslinking

[0082] In this comparative example, microwave-assisted crosslinking is not introduced during the heating stage of the secondary polymerization reaction in step S3. The operating conditions for the remaining steps S1, S2, S3 (excluding the microwave-assisted crosslinking portion), and S4 are the same as in Example 1.

[0083] To verify the performance of the composite material prepared in this invention, we set up a control group and conducted performance tests.

[0084] Control group setup:

[0085] Control group A (composite material prepared in Example 1): prepared according to the detailed steps of Example 1.

[0086] Control group B (water-absorbing resin prepared in Comparative Example 1): prepared according to the detailed steps of Comparative Example 1.

[0087] Control group C (water-absorbing resin prepared in Comparative Example 2): prepared according to the detailed steps of Comparative Example 2.

[0088] Control group D (composite material prepared in Comparative Example 3): prepared according to the detailed steps of Comparative Example 3.

[0089] Performance testing methods:

[0090] Water absorption ratio test: Weigh the dried composite granules or water-absorbing resin powder, then immerse them in deionized water until swelling equilibrium is reached. After removal, absorb the surface moisture with filter paper and weigh again.

[0091] Adsorption performance test (taking ammonia nitrogen adsorption as an example): Prepare an ammonia nitrogen solution of a certain concentration. Add a known mass of composite particles or water-absorbing resin to the ammonia nitrogen solution and adsorb for a certain period of time in a constant-temperature shaker. Take the supernatant and determine the concentration of ammonia nitrogen after adsorption using Nessler's reagent colorimetric method.

[0092] Morphological characterization: The microstructure of the composite material, including the pore structure and zeolite dispersion, was observed using scanning electron microscopy (SEM), as shown in Table 2.

[0093]

[0094] Results Analysis: As can be seen from the table above:

[0095] Although the control group B (water-absorbing resin without zeolite) had a higher water absorption rate, its ammonia nitrogen adsorption capacity was much lower than that of the composite material containing zeolite, indicating that zeolite played a key role in the adsorption process.

[0096] The water absorption ratio and adsorption amount of control group C (without segmented in-situ polymerization) were lower than those of control group A, and the structure was not uniform. This indicates that segmented polymerization is beneficial for the penetration and uniform polymerization of monomer solution in the foam skeleton, thereby forming a more uniform and regular network structure.

[0097] The water absorption ratio and adsorption amount of control group D (without microwave-assisted crosslinking) were also lower than those of control group A, and the structural regularity was poor. This indicates that microwave-assisted crosslinking is beneficial to forming a more complete crosslinking network and improving the stability and adsorption performance of the material.

[0098] Control group A (the composite material prepared according to the method of the present invention) showed the best performance in terms of water absorption ratio and ammonia nitrogen adsorption capacity, and had a regular three-dimensional porous network structure with uniform zeolite dispersion, which proved the superiority of the method of the present invention.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any ordinary changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing water-absorbing resin based on acidic zeolite molecular sieves, characterized in that, Includes the following steps: S1. Pre-fabrication of natural polysaccharide-based foam template and embedding of zeolite: First, mix corn starch and water at a mass ratio of 1:8 to 1:15, place them in a reaction vessel equipped with a mechanical stirrer, and stir at 100 to 300 rpm for 10 to 20 minutes at 25°C until a uniformly dispersed starch slurry is formed. The starch slurry is then heated at 70°C to 95°C while being sheared and stirred at 500 to 800 rpm for 15 to 20 minutes until an initial foam with an average pore size of 50 to 100 micrometers is formed. During this process, Tween-80 surfactant, at a total mass percentage of 0.01~0.1%, is added in two equal portions. The first portion is added after stirring for 5 minutes, and the second portion is added after stirring for 10 minutes. Acidic zeolite molecular sieves are dispersed in the foam at a mass fraction of 15-20%; and then cooled to 0-10℃ to form a solid foam framework containing dispersed zeolite. S2. Monomer Solution Infiltration and Segmented In-situ Polymerization: Prepare a monomer solution containing a water-absorbing monomer, a crosslinking agent, and an initiator; the components of the monomer solution, by total mass percentage, are: acrylic acid 60%~75%, acrylamide 20%~25%, N,N'-methylenebisacrylamide crosslinking agent 0.3%~0.4%, potassium persulfate initiator 0.05%~0.08%, and N,N,N',N'-tetramethylethylenediamine co-initiator 0.01%~0.02%, with the balance being deionized water. The monomer solution is injected dropwise into the solid foam skeleton in 2-4 portions. After each injection, a polymerization reaction is carried out at a temperature range of 20℃-50℃, with each stage of polymerization lasting 30-90 minutes, forming a gel-like polymer. S3. Heating, Curing, Structure Release, and Crosslinking: The gel-like polymer obtained in step S2 is heated to 60℃~90℃ at a heating rate of 1℃ / min~3℃ / min and held within this temperature range for a period of time to carry out a secondary polymerization reaction. Simultaneously, the foam peg is degraded to release the channel structure. Continue the post-curing reaction within a temperature range of 70℃ to 95℃ until a highly cross-linked composite with an acidic zeolite-water-absorbing resin three-dimensional network is formed. The secondary polymerization reaction involves microwave-assisted crosslinking during the heating stage, with a microwave power of 200W~400W and an irradiation time of 2 minutes~6 minutes; the post-curing reaction is maintained at a temperature range of 75℃~85℃ for 2~4 hours. S4. Freeze-drying and post-treatment: The composite obtained in step S3 is freeze-dried at a temperature range of -70℃ to -40℃ for 24 to 72 hours. The dried product is then ground and sieved through a 100-200 mesh sieve to obtain composite particles.

2. The method for preparing water-absorbing resin based on acidic zeolite molecular sieves according to claim 1, characterized in that, The acidic zeolite molecular sieve is of type ZSM-5, with a Si / Al molar ratio of 1600±20 and an average particle size of 120nm.

3. The method for preparing a water-absorbing resin based on an acidic zeolite molecular sieve according to claim 2, characterized by, In step S1, the acidic zeolite molecular sieve is ultrasonically dispersed at 200-300W for 20-35 minutes before dispersion, and then centrifuged at 1800-2500rpm for 8-15 minutes.

4. The method for preparing water-absorbing resin based on acidic zeolite molecular sieves according to claim 2, characterized in that, In step S1, the zeolite suspension is slowly added to the foam at a rate of 0.15 mL / min to 0.5 mL / min using a syringe pump, while stirring at a low speed of 50 rpm to 100 rpm for 5 to 20 minutes. Then, the foam containing zeolite is rapidly cooled to 0°C and kept there for 2 to 4 hours.

5. The method for preparing a water-absorbing resin based on an acidic zeolite molecular sieve according to claim 4, characterized by, After the monomer solution is prepared, it is subjected to vacuum degassing for 20 to 40 minutes to remove dissolved oxygen.

6. The method for preparing water-absorbing resin based on acidic zeolite molecular sieves according to claim 5, characterized in that, In step S2, after each monomer injection, the solid foam skeleton is under a slightly positive pressure nitrogen atmosphere with a pressure of 0.03MPa~0.07MPa.

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