Composite dehumidifying material for rotating wheel and preparation method and application thereof

Abstract

The application discloses a composite dehumidification material for a rotating wheel and a preparation method and application thereof. In the preparation, linear polyacrylic acid sodium is uniformly mixed with sodium water glass to obtain a mixed slurry; glass fibers in a honeycomb shape are immersed in the mixed slurry, and the intermediate 1 is obtained by drying in a carbon dioxide atmosphere; the intermediate 1 is put into an acid liquid to react to obtain the intermediate 2; the intermediate 2 is soaked in water for multiple times until the pH value of the water after soaking reaches 5-6.5, and then the intermediate 2 is soaked in C 1‑3 alcohol solvent, and the intermediate 3 is obtained by drying; the intermediate 3, diisocyanate and a catalyst are dispersed in an organic solvent to react, then a dendritic polymer with a hydroxyl end group and an intramolecular cavity is added to react to generate the composite dehumidification material for the rotating wheel. The composite dehumidification material prepared by the method has both desorption efficiency and adsorption capacity, can achieve the purpose of reducing desorption energy consumption under the premise of ensuring the dehumidification efficiency of the rotating wheel, and is suitable for preparing the dehumidification rotating wheel.

Description

Technical Field

[0001] This invention relates to the field of gas dehumidification technology, specifically to a composite dehumidification material for dehumidifiers, its preparation method, and its application. Background Technology

[0002] In recent years, rotary dehumidification technology has been increasingly widely used in people's daily lives, covering everything from large-scale production fields such as electronics, pharmaceuticals, and food to small-scale residential fresh air systems. However, the desorption of the rotary wheel core often requires the use of electric heating to raise the temperature of the desorbed air to over 100 degrees Celsius. This undoubtedly leads to energy waste in the current context of vigorously developing carbon compliance and carbon neutrality. However, with current dehumidification technology, using a rotary wheel for humidity control remains an irreplaceable method. Therefore, how to reduce the desorption temperature of the rotary wheel core is undoubtedly a problem that urgently needs to be solved. Summary of the Invention

[0003] The purpose of this invention is to overcome one or more shortcomings in the prior art and provide a method for preparing an organic-inorganic composite dehumidifying material with both high adsorption capacity and low desorption temperature. The composite dehumidifying material prepared by this method can reduce its desorption energy consumption while ensuring the dehumidification efficiency of the rotary dehumidifier.

[0004] The present invention also provides an organic-inorganic composite dehumidifying material for a dehumidifier prepared by the above method.

[0005] The present invention also provides an application of the above-mentioned composite dehumidifying material in the preparation of a dehumidifying impeller.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A method for preparing a composite dehumidifying material for rotary dehumidifiers, the method comprising:

[0008] Linear sodium polyacrylate and sodium silicate are mixed to obtain a slurry;

[0009] Pre-formed honeycomb-shaped glass fibers are impregnated in the mixed slurry and then dried in a carbon dioxide atmosphere to obtain intermediate 1; wherein, during the drying process, carbon dioxide reacts with sodium silicate to generate silica gel and sodium carbonate.

[0010] The intermediate 1 was placed in an acid solution and reacted to obtain intermediate 2;

[0011] The intermediate 2 was soaked in water multiple times until the pH of the soaking water reached 5-6.5, and then soaked in C. 1-3 In an alcohol solvent, after drying, intermediate 3 is obtained;

[0012] The intermediate 3, diisocyanate, and catalyst are dispersed in an organic solvent and reacted. Then, a dendritic polymer with hydroxyl end groups and intramolecular cavities is added and reacted to generate a composite dehumidifying material for a rotary wheel.

[0013] In this invention, drying in a carbon dioxide atmosphere first allows the sodium silicate to react and form silica gel as early as possible, and also generates sodium carbonate. During the subsequent acid reaction, not only can the unreacted sodium silicate be reacted away, but the presence of sodium carbonate can further improve the pore structure.

[0014] According to some preferred aspects of the invention, the linear sodium polyacrylate has a molecular weight of 2000-20000, which makes it more soluble in water.

[0015] According to some preferred aspects of the invention, the modulus of the sodium silicate is 2.2 to 3.3.

[0016] In some embodiments of the present invention, the linear sodium polyacrylate is added in the form of an aqueous solution of linear sodium polyacrylate, the solid content of which is 10%-45%.

[0017] In some embodiments of the present invention, the solid content of the sodium silicate is 20%-45%.

[0018] According to some preferred aspects of the present invention, the volume ratio of the linear sodium polyacrylate aqueous solution to the sodium silicate is 1:2-5.

[0019] In some embodiments of the present invention, the acid solution is one or more combinations selected from aqueous sulfuric acid, hydrochloric acid, and aqueous phosphoric acid; and / or, the mass concentration of the acid solution is 10%-30%.

[0020] In some embodiments of the present invention, during the preparation of the intermediate 2, the reaction is carried out in the acid solution at a temperature of 40-80°C for a time of 0.5-6 hours.

[0021] In some preferred embodiments of the present invention, during the process of soaking the intermediate 2 in water, the soaking time is 3-72 hours, and the water is changed every 1-12 hours until the pH value of the soaked water reaches 5.5-6.5.

[0022] In some preferred embodiments of the present invention, the C 1-3 The alcohol solvent is ethanol.

[0023] In some preferred embodiments of the present invention, immersion in C 1-3 The time in alcohol solvents is 1-8 hours.

[0024] According to some preferred and specific aspects of the invention, the diisocyanate is one or more selected from toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and lysine diisocyanate.

[0025] According to some preferred aspects of the invention, the amount of the diisocyanate fed into the intermediate 3 is 0.5%-5% by mass percentage.

[0026] According to some preferred aspects of the invention, the catalyst is dibutyltin dilaurate (DBTDL).

[0027] According to some preferred aspects of the invention, the amount of catalyst fed is 0.01%-0.1% of the mass of the diisocyanate, by weight percentage.

[0028] According to some preferred aspects of the invention, the organic solvent is N,N-dimethylformamide (DMF).

[0029] According to some preferred aspects of the invention, the reaction of the intermediate 3 with the diisocyanate is carried out at 50-90°C.

[0030] In some preferred embodiments of the present invention, the reaction time of the intermediate 3 with the diisocyanate is 0.25-2h.

[0031] According to some preferred and specific aspects of the present invention, the dendritic polymer is one or more of the following: hyperbranched polyester CYD-H10P (8 terminal hydroxyl groups), hyperbranched polyester CYD-H20P (16 terminal hydroxyl groups), hyperbranched polyester CYD-H30P (32 terminal hydroxyl groups), and hyperbranched polyester CYD-H40P (64 terminal hydroxyl groups), which are respectively purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.

[0032] According to some preferred aspects of the invention, the mass percentage of the dendritic polymer is 2%-25% of the mass of the intermediate 3. Further, the mass percentage of the dendritic polymer is 5%-25% of the mass of the intermediate 3. Even further, the mass percentage of the dendritic polymer is 10%-25% of the mass of the intermediate 3.

[0033] According to some preferred aspects of the invention, the reaction following the addition of the dendritic polymer is carried out at 50-90°C.

[0034] In some preferred embodiments of the present invention, the reaction time after the addition of the dendritic polymer is 0.5-3 h.

[0035] In some preferred embodiments of the present invention, after the reaction following the addition of the dendritic polymer is completed, the material is first washed with the organic solvent. After washing, it is soaked in water and ethanol respectively. After removal, it is washed with ethanol and then dried to obtain the composite dehumidifying material for the rotor. Further, the soaking time in water is 3-6 hours, during which the water is changed every 0.4-0.6 hours, and the soaking time in ethanol is 1-8 hours.

[0036] Another technical solution provided by the present invention: a composite dehumidifying material for a rotary dehumidifier prepared by the preparation method of the above-mentioned composite dehumidifying material for a rotary dehumidifier.

[0037] Another technical solution provided by the present invention: the application of the above-mentioned composite dehumidifying material for dehumidifying impellers in the preparation of dehumidifying impellers.

[0038] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0039] This invention innovatively uses dendritic polymers with numerous hydrophilic groups and intramolecular cavities to modify silica gel. First, linear sodium polyacrylate is mixed with sodium silicate via physical blending. During the drying process, the silicate reacts with carbon dioxide to transform into silica gel and sodium carbonate. Simultaneously, the sodium polyacrylate, uniformly mixed in the silicate, precipitates and disperses within the silica gel. During the reaction with acid, the sodium carbonate in the silica gel is removed, thereby increasing the porosity of the silica gel. At the same time, some of the sodium polyacrylate dissolves into the liquid. After further washing and soaking in water, since linear sodium polyacrylate is readily soluble in water, most of the sodium polyacrylate is dissolved and removed, forming larger pores in the silica gel. Subsequently, the silica gel is soaked in C... 1-3 The process using alcohol solvents can replace water molecules in silica gel with C2O2. 1-3 Alcohol solvent molecules, while C has strong volatility and a relatively low boiling point. 1-3Alcohol solvents do not easily damage the pore structure during drying, which is beneficial to increasing the specific surface area of ​​the material. Subsequently, one end of the diisocyanate is grafted onto the silanol group of silica gel, and then the isocyanate group at the other end reacts with one of the hydroxyl groups of the dendritic polymer, fixing it to the silica gel surface through chemical bonds. The pores formed by the dissolution of sodium polyacrylate are also filled by it. Unreacted isocyanate and dendritic polymer can be removed later, and finally an organic-inorganic composite dehumidifying material with the porous structure of silica gel, the intramolecular cavity of dendritic polymer, and a large number of hydrophilic sites is obtained. Practice shows that this type of dehumidifying material requires less energy for desorption than conventional silica gel, which can significantly improve its desorption efficiency. At the same time, the presence of a large number of hydrophilic sites and the presence of porous and cavity structures can greatly improve the adsorption capacity of the material, thus balancing desorption efficiency and adsorption capacity, thereby achieving the goal of reducing desorption energy consumption while ensuring the dehumidification efficiency of the rotary dehumidifier. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the sample adsorption test in an embodiment of the present invention. Detailed Implementation

[0041] The above-mentioned solution will be further described below with reference to specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0042] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0043] In the following description, DMF is N,N-dimethylformamide, HDI is hexamethylene diisocyanate, and DBTDL is dibutyltin dilaurate.

[0044] Example 1

[0045] This example provides a method for preparing a composite dehumidifying material for rotary dehumidifiers, the method comprising:

[0046] Prepare a 3L slurry of sodium polyacrylate aqueous solution / sodium silicate mixture. The sodium polyacrylate has a molecular weight of approximately 5100, the sodium polyacrylate aqueous solution has a solid content of 40%, and the sodium silicate has a modulus of 3.1 and a solid content of 40%, with a volume ratio of 1:3. Take pre-cut 100mm... 3 The honeycomb-shaped glass fiber substrate is impregnated with the mixed slurry. After the substrate is completely impregnated, it is taken out and placed in a vacuum drying oven to dry, during which carbon dioxide is introduced into the oven.

[0047] Prepare 5 L of 25% phosphoric acid aqueous solution, put the dried sample into it, and react at 50℃ for 2 h while stirring. After taking it out, rinse it with running water and soak it in clean water. Change the water every 12 h for a total of 36 h. Then take out the sample and blow off the water stains on its surface. Then soak it in anhydrous ethanol for 6 h. After soaking, take it out and put it in a vacuum drying oven to dry.

[0048] After the sample cooled, its mass was measured to be 166.3g. 5L of DMF was taken, and 5.0g of HDI and 0.025g of DBTDL were added to it. After dispersing evenly, the sample was placed in it and reacted at 70℃ for 0.5h. Then, the temperature was lowered to 50℃ and 26.0g of dendritic polymer CYD-H20P (containing 16 terminal hydroxyl groups, purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.) was added to it. The reaction was continued for 2h with stirring.

[0049] After the reaction is complete, the sample is taken out and rinsed with DMF, then soaked in clean water for 6 hours. When the soaking time is halfway through, the clean water is changed once. Then the surface water stains are blown off and the sample is soaked in ethanol for 8 hours. Finally, the sample is taken out and dried in a vacuum drying oven to obtain the composite dehumidifying material for the rotor.

[0050] Example 2

[0051] This example provides a method for preparing a composite dehumidifying material for rotary dehumidifiers, the method comprising:

[0052] Prepare a 3L slurry of sodium polyacrylate aqueous solution / sodium silicate mixture. The sodium polyacrylate has a molecular weight of approximately 2100, the sodium polyacrylate aqueous solution has a solid content of 30%, the sodium silicate has a modulus of 3.3, and the sodium silicate has a solid content of 35%, with a volume ratio of 1:4. Take pre-cut 100mm pieces... 3 The honeycomb-shaped glass fiber substrate is impregnated with the mixed slurry. After the substrate is completely impregnated, it is taken out and placed in a vacuum drying oven to dry, during which carbon dioxide is introduced into the oven.

[0053] Prepare 4 L of 20% phosphoric acid aqueous solution, put the dried sample into it, and react at 60℃ for 1.5 h while stirring. After taking it out, rinse it with running water and soak it in clean water, changing the water every 1 h for a total of 6 h. Then take out the sample and blow off the water stains on its surface, and then soak it in anhydrous ethanol for 8 h. After soaking, take it out and put it in a vacuum drying oven to dry.

[0054] After the sample cooled, its mass was measured to be 151.1 g. 3 L of DMF was taken, and 6.5 g of HDI and 0.032 g of DBTDL were added to it. After dispersing evenly, the sample was placed in it and reacted at 60 °C for 1 h. Then, 30.0 g of dendritic polymer CYD-H30P (containing 32 terminal hydroxyl groups, purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.) was added to it, and the reaction was continued at 60 °C for 2 h with stirring during the process.

[0055] After the reaction is complete, the sample is taken out and rinsed with DMF, then soaked in clean water for 4 hours. When the soaking time is halfway through, the clean water is changed once. Then the surface water stains are blown off and the sample is soaked in ethanol for 6 hours. Finally, the sample is taken out and dried in a vacuum drying oven to obtain the composite dehumidifying material for the rotor.

[0056] Example 3

[0057] This example provides a method for preparing a composite dehumidifying material for rotary dehumidifiers, the method comprising:

[0058] Prepare a 3L slurry of sodium polyacrylate aqueous solution / sodium silicate mixture. The sodium polyacrylate has a molecular weight of approximately 18,100, the sodium polyacrylate aqueous solution has a solid content of 25%, the sodium silicate has a modulus of 2.5, and a solid content of 43%, with a volume ratio of 2:5. Take pre-cut 100mm pieces... 3 The honeycomb-shaped glass fiber substrate is impregnated with the mixed slurry. After the substrate is completely impregnated, it is taken out and placed in a vacuum drying oven to dry, during which carbon dioxide is introduced into the oven.

[0059] Prepare 3L of 20% hydrochloric acid aqueous solution, put the dried sample into it, and react at 40℃ for 4h while stirring. After taking it out, rinse it with running water and soak it in clean water, changing the water every 2h for a total of 8h. Then take out the sample and blow off the water stains on its surface, and then soak it in anhydrous ethanol for 1h. After soaking, take it out and put it in a vacuum drying oven to dry.

[0060] After the sample cooled, its mass was measured to be 162.6 g. 6 L of DMF was taken, and 8.1 g of HDI and 0.040 g of DBTDL were added to it. After dispersing evenly, the sample was placed in it and reacted at 80 °C for 0.25 h. Then, the temperature was lowered to 70 °C and a mixture of 32.0 g of dendritic polymer CYD-H10P (containing 8 terminal hydroxyl groups, purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.) and CYD-H40P (containing 64 terminal hydroxyl groups, purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.) was added in a mass ratio of 1:1. The reaction was continued for 1 h with stirring.

[0061] After the reaction is complete, the sample is taken out and rinsed with DMF, then soaked in clean water for 6 hours. When the soaking time is halfway through, the clean water is changed once. Then the surface water stains are blown off and the sample is soaked in ethanol for 3 hours. Finally, the sample is taken out and dried in a vacuum drying oven to obtain the composite dehumidifying material for the rotor.

[0062] Comparative Example 1

[0063] It is basically the same as Example 1, except that sodium polyacrylate is not used and dendritic polymers are not grafted.

[0064] Specific preparation methods include:

[0065] Prepare 3L of sodium silicate slurry with a modulus of 3.1 and a solid content of 40%. Take pre-cut 100mm pieces... 3 The honeycomb-shaped glass fiber substrate is impregnated with the slurry. After the substrate is completely impregnated, it is taken out and placed in a vacuum drying oven to dry, during which carbon dioxide is introduced into the oven.

[0066] Prepare 5 L of 25% phosphoric acid aqueous solution, put the dried sample into it, and react at 50℃ for 2 h while stirring. After taking it out, rinse it with running water and soak it in clean water. Change the water every 12 h for a total of 36 h. Then take out the sample and blow off the water stains on its surface. Then soak it in anhydrous ethanol for 6 h. After soaking, take it out and put it in a vacuum drying oven to dry.

[0067] After the sample cooled, its mass was measured to be 201.9 g. 5 L of DMF was taken, the sample was placed in it, and it was stirred at 70 °C for 0.5 h. Then, the temperature was lowered to 50 °C and stirring was continued for 2 h.

[0068] The sample was taken out and rinsed with DMF, then soaked in clean water for 6 hours. When the soaking time was halfway through, the water was changed once. Then the surface water stains were blown off and the sample was soaked in ethanol for 8 hours. Finally, the sample was taken out and dried in a vacuum drying oven to obtain the composite dehumidifying material for the rotor.

[0069] Comparative Example 2

[0070] It is basically the same as Example 1, except that sodium polyacrylate is not used.

[0071] Specific preparation methods include:

[0072] Prepare 3L of sodium silicate slurry with a modulus of 3.1 and a solid content of 40%. Take pre-cut 100mm pieces... 3 The honeycomb-shaped glass fiber substrate is impregnated with the slurry. After the substrate is completely impregnated, it is taken out and placed in a vacuum drying oven to dry, during which carbon dioxide is introduced into the oven.

[0073] Prepare 5 L of 25% phosphoric acid aqueous solution, put the dried sample into it, and react at 50℃ for 2 h while stirring. After taking it out, rinse it with running water and soak it in clean water. Change the water every 12 h for a total of 36 h. Then take out the sample and blow off the water stains on its surface. Then soak it in anhydrous ethanol for 6 h. After soaking, take it out and put it in a vacuum drying oven to dry.

[0074] After the sample cooled, its mass was measured to be 203.7g. 5L of DMF was taken, and 5.0g of HDI and 0.025g of DBTDL were added to it. After dispersing evenly, the sample was placed in it and reacted at 70℃ for 0.5h. Then, 26.0g of dendritic polymer CYD-H20P (containing 16 terminal hydroxyl groups, purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.) was added. After cooling to 50℃, the reaction was continued for 2h, with stirring during the process.

[0075] After the reaction is complete, the sample is taken out and rinsed with DMF, then soaked in clean water for 6 hours. When the soaking time is halfway through, the clean water is changed once. Then the surface water stains are blown off and the sample is soaked in ethanol for 8 hours. Finally, the sample is taken out and dried in a vacuum drying oven to obtain the composite dehumidifying material for the rotor.

[0076] Performance testing

[0077] The materials obtained in Examples 1-3 and Comparative Examples 1-3 were dried to constant weight, and their initial mass m0 was recorded. Dynamic adsorption was then performed (method as follows). Figure 1 As shown in the figure, during the test, the honeycomb surface of the sample was always facing the flowing wind with a temperature of 15℃, a relative humidity of 85%, and a face wind speed of 2.0m / s. After a total of 7.5 minutes, the sample was taken out of the test environment and its adsorption mass m1 was recorded. Its adsorption amount Δm1=m1-m0.

[0078] The desorption performance was then tested. The sample was placed in a dedicated desorption device (with no air leakage after the sample was placed in the desorption chamber) and desorbed for 2.5 minutes with flowing hot air at a face velocity of 2.0 m / s. The mass m2 was then taken out and recorded. The desorption amount Δm2 = m1 - m2, and the desorption rate = (Δm2 / Δm1) × 100%.

[0079] Adsorption tests were performed immediately after the desorption was completed, followed by desorption tests. In this adsorption-desorption cycle, the desorption rate of the sample showed a gradual upward trend. Almost all samples were able to achieve a desorption rate of around 100% after 6-8 cycles. Tables 1 and 2 record the adsorption amount and desorption rate data of each sample in the first three adsorption-desorption cycles at 100℃, 80℃ and 60℃ respectively.

[0080] Table 1 Adsorption data of each sample at different desorption temperatures

[0081]

[0082] Table 2. Desorption rate data for each sample at different desorption temperatures.

[0083]

[0084]

[0085] The comparison results between Example 1 and Comparative Example 1 show that the organic-inorganic composite desiccant prepared by the method described in this invention, compared with single inorganic silica gel material, has a significantly improved desorption efficiency due to the introduction of dendritic polymers with a large number of intramolecular cavities and hydrophilic end groups as a medium for storing water molecules. Furthermore, the energy required for desorption of the polymer desiccant is lower than that of silica gel. The effect on adsorption capacity is negligible. In fact, when a stable adsorption-desorption cycle is reached (when the desorption rate reaches or approaches 100%), its adsorption capacity is even higher than that of pure silica gel material.

[0086] The comparison between Example 1 and Comparative Example 2 shows that, without creating cavities by first mixing soluble sodium polyacrylate into the precursor and then dissolving it, directly grafting the dendritic polymer onto the silica gel surface, while significantly improving desorption efficiency, leads to a precipitous drop in adsorption capacity. Practical analysis suggests that when the silica gel structure lacks sufficient space, the polymer can only graft onto the outer layer of the silica gel, which in turn acts as a shield for the active sites on which the silica gel adsorbs water vapor. Furthermore, the efficiency of the polymer's hydrophilic end groups in capturing water molecules from the air is far lower than that of porous silica gel, thus resulting in a decrease in adsorption capacity per unit time.

[0087] In summary, the organic-inorganic composite dehumidifying material prepared by the method described in this invention not only has a high adsorption capacity but also can effectively reduce the desorption temperature, showing great application potential in low-temperature desorption dehumidifying rotor systems.

[0088] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0089] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A method for preparing a composite dehumidifying material for rotary dehumidifiers, characterized in that, The preparation method includes: Linear sodium polyacrylate and sodium silicate are mixed to obtain a mixed slurry; wherein, the linear sodium polyacrylate is added in the form of an aqueous solution of linear sodium polyacrylate, the solid content of the aqueous solution of linear sodium polyacrylate is 10%-45%, the solid content of the sodium silicate is 20%-45%, and the volume ratio of the aqueous solution of linear sodium polyacrylate to the sodium silicate is 1:2-5. Pre-formed honeycomb-shaped glass fibers are impregnated in the mixed slurry and then dried in a carbon dioxide atmosphere to obtain intermediate 1; wherein, during the drying process, carbon dioxide reacts with sodium silicate to generate silica gel and sodium carbonate. The intermediate 1 was placed in an acid solution and reacted to obtain intermediate 2; The intermediate 2 was soaked in water multiple times until the pH of the soaking water reached 5-6.5, and then soaked in C. 1-3 In an alcohol solvent, after drying, intermediate 3 is obtained; The intermediate 3, diisocyanate, and catalyst are dispersed in an organic solvent and reacted. Then, a dendritic polymer with hydroxyl end groups and intramolecular cavities is added and reacted to generate a composite dehumidifying material for a rotary wheel. The amount of diisocyanate fed is 0.5%-5% of the mass of the intermediate 3, and the mass of the dendritic polymer fed is 2%-25% of the mass of the intermediate 3.

2. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, The linear sodium polyacrylate has a molecular weight of 2000-20000.

3. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, The modulus of the sodium silicate is 2.2 to 3.

3.

4. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, The acid solution is selected from one or more of the following: aqueous sulfuric acid solution, aqueous hydrochloric acid solution, and aqueous phosphoric acid solution.

5. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, The mass concentration of the acid solution is 10%-30%.

6. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, In the preparation of intermediate 2, the reaction is carried out in the acid solution at a temperature of 40-80°C for a time of 0.5-6 hours.

7. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, During the process of soaking the intermediate 2 in water, the soaking time is 3-72 hours, and the water is changed every 1-12 hours until the pH value of the soaked water reaches 5.5-6.

5.

8. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, The C 1-3 The alcohol solvent is ethanol.

9. The method for preparing the composite dehumidifying material for rotary dehumidifiers according to claim 1, characterized in that, Soaking in C 1-3 The time in alcohol solvents is 1-8 hours.

10. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The diisocyanate is selected from one or more combinations of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and lysine diisocyanate.

11. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The catalyst is dibutyltin dilaurate.

12. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The amount of catalyst fed is 0.01%-0.1% of the mass of the diisocyanate, based on mass percentage.

13. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The organic solvent is N,N-dimethylformamide.

14. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The reaction between intermediate 3 and the diisocyanate is carried out at 50-90°C.

15. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The dendritic polymer is selected from one or more of the following: hyperbranched polyester CYD-H10P, hyperbranched polyester CYD-H20P, hyperbranched polyester CYD-H30P, and hyperbranched polyester CYD-H40P, purchased from Weihai Chenyuan Molecular New Materials Co., Ltd.

16. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, The reaction following the addition of the dendritic polymer was carried out at 50-90°C.

17. The method for preparing the composite dehumidifying material for a rotary dehumidifier according to claim 1, characterized in that, After the reaction following the addition of the dendritic polymer is completed, the material is first washed with the organic solvent, then soaked in water and ethanol respectively, removed and washed with ethanol, and then dried to obtain the composite dehumidifying material for the rotor.

18. A composite dehumidifying material for a desiccant wheel prepared by the method for preparing the composite desiccant for a desiccant wheel according to any one of claims 1-17.

19. The application of the composite dehumidifying material for a dehumidifying impeller as described in claim 18 in the preparation of a dehumidifying impeller.

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