A method for preparing an air-breathing composite material with high adsorption capacity

Abstract

The application discloses a preparation method of an air absorption composite material with high adsorption capacity, belongs to the field of adsorption material preparation, and aims at solving the technical problem that the adsorption capacity and structural stability of the air absorption composite material in the prior art need to be further improved, and specifically comprises the following steps: stirring hybrid sol, epoxy-based silane grafted UiO-66 and modified polyether amine curing agent in a reaction kettle, heating the reaction kettle to 25-35 DEG C, and keeping the temperature and stirring for 30-60 min; and obtaining air absorption composite slurry through post-treatment; the hybrid sol, the epoxy-based silane grafted UiO-66 and the modified polyether amine curing agent are blended, then an organic-inorganic interpenetrating network is formed through epoxy-amine ring-opening addition curing, and the air absorption composite material with high adsorption capacity is obtained through segmented temperature rising activation.

Description

Technical Field

[0001] This invention relates to the field of adsorption material preparation, and more specifically to a method for preparing a gas-absorbing composite material with high adsorption capacity. Background Technology

[0002] As a key functional material for maintaining a vacuum environment, getter composites have undergone a technological evolution in adsorption performance, progressing from evaporative to non-evaporative types and from single physical adsorption to physicochemical synergistic adsorption. Early evaporative getters, mainly composed of thin films or alloy powders of metals such as barium and titanium, relied on chemical adsorption on fresh metal surfaces. However, these had limitations such as high activation temperatures, evaporation contamination, and irreversible saturation. With the advancement of ultra-high vacuum technology, bulk getters, represented by non-evaporative alloys such as zirconium-vanadium-iron and zirconium-aluminum, have gradually developed. These materials form surface-enriched active sites through high-temperature activation, enabling continuous adsorption of active gases such as hydrogen, carbon monoxide, and nitrogen. However, in practical applications, these composite systems still face multiple challenges, including organic-inorganic interface compatibility, matrix thermal stability, and the integrity of the high-temperature activated structure, placing higher demands on the comprehensive performance of getter materials.

[0003] Currently, getter composites typically use epoxy resin, phenolic resin, or silicone resin as organic carriers, loading inorganic getter components such as zirconium-based alloy powder and activated carbon through physical blending. These are then modified using methods such as high-temperature sintering, metal impregnation loading, or surface acid-base treatment to improve dispersibility and adsorption activity. Some studies employ silane coupling agents to modify the surface of inorganic fillers, mitigating interfacial phase separation by improving wettability, or introducing noble metal catalytic components such as palladium and platinum to promote hydrogen dissociation and adsorption. While these methods improve getter performance to some extent, physically blended composite systems cannot fundamentally solve the interfacial bonding problem between inorganic fillers and the organic matrix. During high-temperature activation, micropores are prone to collapse due to matrix shrinkage, and traditional organic resin matrices exhibit high self-decomposition and gas generation under high-temperature vacuum conditions. Furthermore, the lack of coordinated unsaturated metal active sites restricts the simultaneous improvement of getter capacity and vacuum stability.

[0004] In existing technologies, although MOF materials such as UiO-66 possess high specific surface area and regular microporous structure, after simple physical mixing or conventional coupling treatment with organic resin matrices, there is a lack of stable covalent bonds at the interface. The filler is prone to agglomeration and micropore blockage, significantly reducing the accessibility of gas adsorption sites. At the same time, conventional epoxy resin or silicone resin matrices have insufficient thermal stability during high-temperature curing and subsequent activation, and their self-decomposition and volatile matter content is high. This not only pollutes the vacuum environment but also fails to provide chemical adsorption active sites for gases such as hydrogen and carbon monoxide. Furthermore, when conventional amine curing agents, such as polyetheramine, react with epoxy matrix, the crosslinking network density is limited, and the cured product is brittle and cannot withstand the thermal stress of the high-temperature activation stage, easily leading to matrix cracking and filler detachment. During high-temperature desorption, the micropore channels lack rigid support and are prone to shrinkage and collapse, resulting in a decrease in adsorption capacity. Summary of the Invention

[0005] This invention addresses the technical problem that the adsorption capacity and structural stability of air-absorbing composite materials in the prior art need to be further improved.

[0006] The objective of this invention can be achieved through the following technical solution: a method for preparing a gas-absorbing composite material with high adsorption capacity, comprising the following steps:

[0007] S1. Place the hybrid sol, epoxy silane-grafted UiO-66 and modified polyetheramine curing agent in a reaction vessel and stir. Heat the reaction vessel to 25-35℃, keep it warm and stir for 30-60 minutes, and then process it to obtain the air-absorbing composite slurry.

[0008] S2. Pour the air-absorbing composite slurry into a polytetrafluoroethylene mold, transfer it to a vacuum drying oven protected by nitrogen atmosphere at a temperature of 60-80℃ and cure for 2-4 hours, then raise the temperature to 105-115℃ and cure for 2-4 hours. After crushing, sieve to obtain air-absorbing composite particles.

[0009] S3. The air-absorbing composite particles are subjected to segmented heating, vacuum degassing, and post-curing to obtain the air-absorbing composite material.

[0010] Further, in step S1, the weight ratio of the hybrid sol, epoxy silane grafted UiO-66, and modified polyetheramine curing agent is 100:15-25:15-25. The post-processing step includes: after the reaction is completed, wait for the reaction system to cool to room temperature, transfer the slurry to a vacuum degassing kettle, and degas for 10-15 minutes under a vacuum of -0.08 to -0.09 MPa to obtain a gas-absorbing composite slurry.

[0011] Furthermore, in step S2, the sieving is for collecting particles with a diameter of 20-60 μm.

[0012] Furthermore, in step S3, the specific steps of segmented heating, vacuum degassing, and post-curing are as follows: the gas-absorbing composite particles are placed in a vacuum chamber with a vacuum degree ≤10Pa, and the temperature is first increased to 120-130℃ at 1-2℃ / min and kept at that temperature for 2-3h, and then increased to 180-220℃ at 2-3℃ / min and kept at that temperature for 4-6h to obtain the gas-absorbing composite material.

[0013] Furthermore, the hybrid sol is prepared by the following steps:

[0014] A1. Place tetrabutyl titanate, acetylacetone and xylene in a reaction vessel under nitrogen atmosphere protection, stir at room temperature for 15-25 min to obtain acetylacetone chelated tetrabutyl titanate pre-modified solution.

[0015] A2. Place 3-(2,3-epoxypropoxy)propyltrimethoxysilane, deionized water and ethanol in a reaction vessel and stir. Add an aqueous acetic acid solution, heat the reaction vessel to 45-55℃ and keep it at that temperature for 2-4 hours. Cool the reaction vessel to 30-40℃, add acetylacetone chelated tetrabutyl titanate pre-modified solution, stir at room temperature for 30-60 minutes, remove low-boiling substances by vacuum distillation, heat the reaction vessel to 105-115℃ and keep it at that temperature for 3-5 hours. Post-treatment yields a hybrid sol.

[0016] Furthermore, in step A1, the ratio of tetrabutyl titanate, acetylacetone, and xylene is 45-55g:8-12g:35-45mL.

[0017] Further, in step A2, the ratio of the amount of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, deionized water, ethanol, aqueous acetic acid solution, and acetylacetone chelate tetrabutyl titanate pre-modified solution is 40-60g:6-8mL:50-70mL:4-7mL:38-58g, and the concentration of the aqueous acetic acid solution is 1-3wt%. The post-treatment step includes: after the reaction is completed, the reaction system is cooled to room temperature and degassed for 10-15 min under a vacuum of -0.08 to -0.09 MPa to obtain a hybrid sol.

[0018] Furthermore, the modified polyetheramine curing agent is prepared by: placing polyetheramine and ethanol in a reaction vessel under nitrogen atmosphere and stirring, heating the reaction vessel to 40-50°C, adding hydroxyethyl acrylate, heating the reaction vessel to 55-65°C, maintaining the temperature for 4-6 hours, and then performing post-treatment to obtain the modified polyetheramine curing agent.

[0019] Furthermore, the ratio of polyetheramine, ethanol, and hydroxyethyl acrylate is 85-95g:80-120mL:15-25g. The post-processing steps include: after the reaction is completed, the reaction system is cooled to room temperature, and then distilled under reduced pressure at a vacuum of -0.08 to -0.09MPa and a temperature of 60-80℃ to remove the low-boiling-point solvent, thereby obtaining the modified polyetheramine curing agent.

[0020] Furthermore, the preparation method of the epoxy silane-grafted UiO-66 is as follows: UiO-66 and toluene are placed in a reaction vessel under nitrogen atmosphere protection and dispersed at room temperature for 30-40 min. Then, 3-(2,3-epoxypropoxy)propyltrimethoxysilane is added, the reaction vessel is heated to 60-70℃, and the reaction is maintained for 4-6 h. After post-treatment, epoxy silane-grafted UiO-66 is obtained.

[0021] Furthermore, the ratio of UiO-66, toluene, and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 5-10g:40-60mL:3-5g. The post-processing steps include: after the reaction is completed, the reaction system is cooled to room temperature, centrifuged, the precipitate is collected, the precipitate is washed with toluene 2-4 times, transferred to an oven at 60-70℃, dried for 8-12 hours, and pulverized through a 200-mesh sieve to obtain epoxysilane-grafted UiO-66.

[0022] The present invention has the following beneficial effects:

[0023] 1. The UiO-66 of the present invention, after being grafted with epoxy silane, acquires epoxy reactivity through Si-O-Zr covalent bonds and is embedded in the curing network as a reactive porous crosslinking node. The modified polyetheramine curing agent introduces hydroxyl and ester groups through Michael addition, retaining the active hydrogen of the amine group while providing hydroxyl synergistic reaction sites. The titanium-silicon network containing epoxy side chains in the hybrid sol participates in crosslinking simultaneously. The three form an organic-inorganic interpenetrating network through epoxy-amine and hydroxyl multifunctional ring-opening addition. UiO-66 no longer exists in the form of physical filler, but is anchored in the matrix as a chemical crosslinking node, inhibiting the separation of inorganic-organic interface phases and maintaining the mechanical properties and gas accessibility of microporous adsorption sites.

[0024] 2. In the hybrid sol of the present invention, acetylacetone chelates Ti(IV) to inhibit rapid hydrolysis, ensuring the controllable condensation polymerization with silane to form Ti-O-Si bonds. High-temperature deep condensation polymerization promotes network densification to reduce gas exhalation rate. Ti(IV) is activated to form coordination unsaturated sites, giving it chemical adsorption activity for H2 and CO. The epoxy side chain and the modified polyetheramine active hydrogen ring-opening addition form an interpenetrating network, anchoring the UiO-66 microporous sites and improving the gas adsorption capacity of the gas-absorbing composite material.

[0025] 3. In the segmented heating and activation process, the present invention also restores the UiO-66 coordination unsaturated metal sites and Ti(IV) active centers in the high-temperature stage. The organic-inorganic interpenetrating cross-linked network provides rigid framework support during the heating process, inhibits the high-temperature shrinkage and collapse of micropores, maintains the connectivity of gas diffusion channels, fully exposes adsorption sites and maintains the integrity of the matrix structure, thereby improving the adsorption capacity of active gas. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The bisphenol A type epoxy resin (E-51) used in this invention was purchased from Jining Fangyu Chemical Co., Ltd., and its model is E-51 with an epoxy value of 0.47-0.54 mol / 100g.

[0028] The UiO-66 used in this invention was purchased from Angxing New Carbon Materials Changzhou Co., Ltd., with a particle size of approximately 100 nm and a BET specific surface area ≥1200 m². 2 / g, pore volume ≥0.45cm 3 / g, model number S33464;

[0029] The polyetheramine used in this invention was purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd., model number llb90461, product name polyetheramine D-230.

[0030] Example 1

[0031] This embodiment provides a method for preparing a gas-getting composite material with high adsorption capacity, specifically including the following steps:

[0032] Step 1: Preparation of epoxy-based silane-grafted UiO-66

[0033] Weigh 50g of UiO-66 and 400mL of toluene and place them in a reaction vessel under nitrogen atmosphere protection. Disperse at room temperature for 30min. Add 30g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane. Heat the reaction vessel to 60℃ and keep it at that temperature for 4h. After the reaction is complete, wait for the reaction system to cool to room temperature, centrifuge, collect the precipitate, wash the precipitate twice with toluene, transfer it to an oven at 60℃ and dry it for 8h. Crush it and pass it through a 200-mesh sieve to obtain epoxysilane-grafted UiO-66.

[0034] The Zr-OH on the surface of UiO-66 undergoes dehydration condensation with the silanyl methoxysilane of 3-(2,3-epoxypropoxy)propyltrimethoxysilane to form Si-O-Zr covalent bonds. This allows silane containing epoxy side chains to be grafted onto the UiO-66 surface, endowing it with epoxy reactivity. This enables it to act as a reactive porous crosslinking node embedded in the epoxy-amine curing network, inhibiting inorganic-organic interfacial phase separation. By controlling the sieving process, the filler gradation is matched with the thermal shrinkage rate of the resin matrix, reducing interfacial shear stress during vacuum degassing and post-curing, and maintaining the structural integrity of the microporous adsorption sites.

[0035] Step 2: Preparation of hybrid sol

[0036] Weigh out 450g of tetrabutyl titanate, 80g of acetylacetone and 350mL of xylene and place them in a reaction vessel under nitrogen atmosphere protection. Stir at room temperature for 15min to obtain acetylacetone chelated tetrabutyl titanate pre-modified solution.

[0037] Weigh 400g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 60mL of deionized water, and 500mL of ethanol and place them in a reaction vessel. Stir, add 40mL of 1wt% acetic acid aqueous solution, heat the reaction vessel to 45℃, and keep it at this temperature for 2h. Cool the reaction vessel to 30℃, add 380g of acetylacetone chelated tetrabutyl titanate pre-modified solution, stir at room temperature for 30min, remove low-boiling substances by vacuum distillation, heat the reaction vessel to 105℃, and keep it at this temperature for 3h. After the reaction is complete, let the reaction system cool to room temperature, and degas it under a vacuum of -0.08MPa for 10min to obtain a hybrid sol.

[0038] Acetylacetone coordinates with Ti(IV) via enol oxygen, reducing the electrophilicity of the titanium center through steric hindrance and electronic effects, thus inhibiting the rapid hydrolysis and self-condensation of tetrabutyl titanate. 3-(2,3-epoxypropoxy)propyltrimethoxysilane hydrolyzes under acetic acid catalysis to generate silanol, which then undergoes controlled condensation with the chelated tetrabutyl titanate to form Ti-O-Si bonds, constructing a titanium-silicon hybrid sol containing epoxy side chains. Acetylacetone chelates Ti(IV) to inhibit rapid hydrolysis, ensuring controllable condensation. After removing low-boiling substances, deep condensation occurs at high temperatures, promoting network densification to reduce gas exudation. During the curing stage at 105-115℃, the epoxy side chains undergo ring-opening addition with active hydrogen from modified polyetheramine to construct an organic-inorganic interpenetrating cross-linked network, anchoring the microporous adsorption sites of UiO-66 and stabilizing the interfacial dispersion.

[0039] Step 3: Preparation of modified polyetheramine curing agent

[0040] Weigh 850g of polyetheramine and 800mL of ethanol and place them in a reaction vessel under nitrogen atmosphere and stir. Heat the reaction vessel to 40℃, add 150g of hydroxyethyl acrylate, heat the reaction vessel to 55℃, and keep the reaction at this temperature for 4h. After the reaction is complete, let the reaction system cool to room temperature, and then distill under reduced pressure at a vacuum of -0.08MPa and a temperature of 60℃ to remove the low-boiling-point solvent, thus obtaining the modified polyetheramine curing agent.

[0041] Step 4: Preparation of air-getting composite material

[0042] Weigh out 1000g of hybrid sol, 150g of epoxy silane-grafted UiO-66 and 150g of modified polyetheramine curing agent and place them in a reaction vessel and stir. Heat the reaction vessel to 25℃ and stir for 30min. After the reaction is complete, wait for the reaction system to cool to room temperature, transfer the slurry to a vacuum degassing vessel and degas for 10min under a vacuum of -0.08MPa to obtain a gas-absorbing composite slurry.

[0043] The air-absorbing composite slurry was poured into a polytetrafluoroethylene mold, transferred to a vacuum drying oven protected by nitrogen atmosphere at 60℃ and cured for 2 hours, then heated to 105℃ and cured for 2 hours. After crushing, it was sieved to obtain air-absorbing composite particles with a particle size of 20μm.

[0044] The air-absorbing composite particles were placed in a vacuum chamber with a vacuum degree ≤10Pa, and the temperature was first increased to 120℃ at 1℃ / min and held for 2h. Then the temperature was increased to 180℃ at 2℃ / min and held for 4h to obtain the air-absorbing composite material.

[0045] Example 2

[0046] This embodiment provides a method for preparing a gas-getting composite material with high adsorption capacity, specifically including the following steps:

[0047] Step 1: Preparation of epoxy-based silane-grafted UiO-66

[0048] Weigh 75g of UiO-66 and 500mL of toluene and place them in a reaction vessel under nitrogen atmosphere protection. Disperse at room temperature for 35min. Add 40g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane. Heat the reaction vessel to 65℃ and keep it at that temperature for 5h. After the reaction is complete, let the reaction system cool to room temperature, centrifuge, collect the precipitate, wash the precipitate 3 times with toluene, transfer it to an oven at 65℃, dry it for 10h, and pulverize it through a 200-mesh sieve to obtain epoxysilane-grafted UiO-66.

[0049] Step 2: Preparation of hybrid sol

[0050] Weigh out 500g of tetrabutyl titanate, 100g of acetylacetone and 400mL of xylene and place them in a reaction vessel under nitrogen atmosphere protection. Stir at room temperature for 20min to obtain acetylacetone chelated tetrabutyl titanate pre-modified solution.

[0051] Weigh 500g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 70mL of deionized water, and 600mL of ethanol and place them in a reaction vessel. Stir, add 55mL of 2wt% acetic acid aqueous solution, heat the reaction vessel to 50℃, and keep it at that temperature for 3h. Cool the reaction vessel to 35℃, add 480g of acetylacetone chelated tetrabutyl titanate pre-modified solution, stir at room temperature for 45min, remove low-boiling substances by vacuum distillation, heat the reaction vessel to 110℃, and keep it at that temperature for 4h. After the reaction is completed, let the reaction system cool to room temperature, and degas it under a vacuum of -0.085MPa for 13min to obtain a hybrid sol.

[0052] Step 3: Preparation of modified polyetheramine curing agent

[0053] Weigh 900g of polyetheramine and 1000mL of ethanol and place them in a reaction vessel under nitrogen atmosphere protection and stir. Heat the reaction vessel to 45℃, add 200g of hydroxyethyl acrylate, heat the reaction vessel to 60℃, and keep the reaction at this temperature for 5h. After the reaction is completed, wait for the reaction system to cool to room temperature, and then distill under reduced pressure at a vacuum of -0.085MPa and a temperature of 70℃ to remove the low-boiling-point solvent, thereby obtaining the modified polyetheramine curing agent.

[0054] The primary amine of polyetheramine undergoes Michael addition with hydroxyethyl acrylate, introducing hydroxyl and ester groups into the molecule while retaining the active hydrogen that reacts with the epoxy group, resulting in a modified polyetheramine curing agent. The polyetheramine and hydroxyethyl acrylate undergo Michael addition reaction, and the primary amine and acrylate undergo conjugated addition to introduce hydroxyl and ester groups, while retaining the active hydrogen for epoxy curing. The flexible polyether segments improve the toughness of the matrix, and the hydroxyl groups participate in epoxy crosslinking to enhance the interfacial bonding and structural stability between the organic carrier and the inorganic getter filler.

[0055] Step 4: Preparation of air-getting composite material

[0056] Weigh out 1000g of hybrid sol, 200g of epoxy silane-grafted UiO-66 and 200g of modified polyetheramine curing agent and place them in a reaction vessel and stir. Heat the reaction vessel to 30℃ and stir for 45min. After the reaction is complete, wait for the reaction system to cool to room temperature, transfer the slurry to a vacuum degassing vessel, and degas for 13min under a vacuum of -0.085MPa to obtain a gas-absorbing composite slurry.

[0057] The air-absorbing composite slurry was poured into a polytetrafluoroethylene mold, transferred to a vacuum drying oven protected by nitrogen atmosphere at 70℃ for 3 hours, and then heated to 110℃ for 3 hours. After crushing, it was sieved to obtain air-absorbing composite particles with a particle size of 40μm.

[0058] The air-absorbing composite particles were placed in a vacuum chamber with a vacuum degree ≤10Pa, and the temperature was first increased to 125℃ at 2℃ / min and held for 2.5h. Then the temperature was increased to 200℃ at 3℃ / min and held for 5h to obtain the air-absorbing composite material.

[0059] Example 3

[0060] This embodiment provides a method for preparing a gas-getting composite material with high adsorption capacity, specifically including the following steps:

[0061] Step 1: Preparation of epoxy-based silane-grafted UiO-66

[0062] Weigh 100g of UiO-66 and 600mL of toluene and place them in a reaction vessel under nitrogen atmosphere protection. Disperse at room temperature for 40min. Add 50g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane. Heat the reaction vessel to 70℃ and keep it at that temperature for 6h. After the reaction is complete, let the reaction system cool to room temperature, centrifuge, collect the precipitate, wash the precipitate 4 times with toluene, transfer it to an oven at 70℃, dry it for 12h, and pulverize it through a 200-mesh sieve to obtain epoxysilane-grafted UiO-66.

[0063] Step 2: Preparation of hybrid sol

[0064] Weigh out 550g of tetrabutyl titanate, 120g of acetylacetone and 450mL of xylene and place them in a reaction vessel under nitrogen atmosphere protection. Stir at room temperature for 25min to obtain acetylacetone chelated tetrabutyl titanate pre-modified solution.

[0065] Weigh 600g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 80mL of deionized water, and 700mL of ethanol and place them in a reaction vessel. Stir, add 70mL of 3wt% acetic acid aqueous solution, heat the reaction vessel to 55℃, and keep it at that temperature for 4h. Cool the reaction vessel to 40℃, add 580g of acetylacetone chelated tetrabutyl titanate pre-modified solution, stir at room temperature for 60min, remove low-boiling substances by vacuum distillation, heat the reaction vessel to 115℃, and keep it at that temperature for 5h. After the reaction is completed, let the reaction system cool to room temperature, and degas it under a vacuum of -0.09MPa for 15min to obtain a hybrid sol.

[0066] Step 3: Preparation of modified polyetheramine curing agent

[0067] Weigh 950g of polyetheramine and 1200mL of ethanol and place them in a reaction vessel under nitrogen atmosphere protection and stir. Heat the reaction vessel to 50℃, add 250g of hydroxyethyl acrylate, heat the reaction vessel to 65℃, and keep the reaction at this temperature for 6h. After the reaction is completed, wait for the reaction system to cool to room temperature, and then distill under reduced pressure at a vacuum of -0.09MPa and a temperature of 80℃ to remove the low-boiling-point solvent, thereby obtaining the modified polyetheramine curing agent.

[0068] Step 4: Preparation of air-getting composite material

[0069] Weigh out 1000g of hybrid sol, 250g of epoxy silane-grafted UiO-66 and 250g of modified polyetheramine curing agent and place them in a reaction vessel and stir. Heat the reaction vessel to 35℃ and stir for 60min. After the reaction is complete, wait for the reaction system to cool to room temperature, transfer the slurry to a vacuum degassing vessel, and degas for 15min under a vacuum of -0.09MPa to obtain a gas-absorbing composite slurry.

[0070] The air-absorbing composite slurry was poured into a polytetrafluoroethylene mold, transferred to a vacuum drying oven protected by nitrogen atmosphere at 80℃ for 4 hours, and then heated to 115℃ for 4 hours. After crushing, it was sieved to obtain air-absorbing composite particles with a particle size of 60μm.

[0071] The air-absorbing composite particles were placed in a vacuum chamber with a vacuum degree ≤10Pa, and the temperature was first increased to 130℃ at 2℃ / min and held for 3h. Then the temperature was increased to 220℃ at 3℃ / min and held for 6h to obtain the air-absorbing composite material.

[0072] Hybrid sol, epoxy silane grafted UiO-66, and modified polyetheramine curing agent are blended together. The epoxy groups, amine groups, and active hydrogen of the hydroxyl group undergo ring-opening addition. After vacuum degassing, the mixture is cured and shaped in stages. Micron-sized particles are obtained by crushing and sieving. Then, the particles are activated by staged heating under ≤10Pa vacuum to remove the adsorbate in the pores, thus obtaining the gas-absorbing composite material.

[0073] Hybrid sol, epoxy-silane grafted UiO-66, and modified polyetheramine curing agent are blended at low temperature to promote the pre-reaction and uniform dispersion of epoxy groups, amine groups, and active hydrogen hydroxyl groups. Vacuum degassing eliminates bubbles, and segmented temperature-curing controls the crosslinking rate and forms a dense network to fix the spatial distribution of fillers and prevent structural collapse during high-temperature activation. The particles are pulverized and sieved to a specific particle size to increase the specific surface area and shorten the gas diffusion path. Segmented temperature-curing activation under high vacuum removes adsorbates from the pores and reconstructs the pore structure, restoring active sites and improving gas adsorption capacity and kinetic performance.

[0074] Comparative Example 1

[0075] The difference between this comparative example and Example 3 is that, in step four, when preparing the air-getting composite material, UiO-66 is used in an equal amount to replace epoxy silane grafting UiO-66.

[0076] Comparative Example 2

[0077] The difference between this comparative example and Example 3 is that, in step four, when preparing the air-getting composite material, polyetheramine is used in an equal amount to replace the modified polyetheramine curing agent.

[0078] Comparative Example 3

[0079] The difference between this comparative example and Example 3 is that, in step four, when preparing the air-getting composite material, an equal amount of bisphenol A type epoxy resin is used to replace the hybrid sol.

[0080] Performance testing:

[0081] Gas adsorption capacity: The gas adsorption capacity of the getter composite materials prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to standard GB / T 25497-2010 "Test Method for Gas Adsorption and Desorption Performance of Getters". The test gases were N2, CO, H2, O2 and H2O. The test environment was 25℃. The static adsorption capacity was used for characterization, and the unit was cm. 3 / g;

[0082] BET specific surface area, pore volume, and pore size distribution: The BET specific surface area, pore volume, and pore size distribution of the gas-absorbing composite materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested according to standard GB / T 19587-2017 "Determination of Specific Surface Area of ​​Solid Substances by Gas Adsorption BET Method". The test temperature was 77K. The BET specific surface area, pore volume, and pore size distribution were used for characterization. The unit for specific surface area is m³ / s. 2 / g, pore volume is in cm 3 / g, pore size is in nm;

[0083] Gas release rate: The gas release rate of the gas-absorbing composite materials prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to the standard GB / T 25497-2010 "Test Method for Gas Release of Gas Containing Getter". The test environment was 25℃, and the gas release rate was used for characterization. The unit is Pa·L / cm.

[0084] Compressive strength and flexural strength: The compressive strength and flexural strength of the getter composite materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested according to the standard GB / T 25496-2010 "Methods for Testing Mechanical Properties of Getter". The test environment was 25℃. The compressive strength and flexural strength were used for characterization. The units are MPa. The specific data are shown in Table 1 below.

[0085] Table 1 - Performance Test Data of Samples

[0086]

[0087] Comparative analysis of the data in Table 1 above shows that the static adsorption capacity of the gas-absorbing composite material prepared in this invention for H2 is 115.3 cm³. 3 The static adsorption capacity for CO is 88.6 cm⁻¹ / g. 3 The static adsorption capacity for N2 is 58.5 cm³ / g. 3 / g, BET specific surface area is 475.6m² 2 / g, pore volume 0.29cm3 / g, pore size 1.80, gas release rate 1.3×10 -3 With a compressive strength of 63.4 MPa and a flexural strength of 54.6 MPa, the results are superior to those of the comparative example.

[0088] In Comparative Example 1, since the surface of UiO-66 was not modified by epoxy silane grafting, there was a lack of covalent bonding between the inorganic filler and the organic matrix, resulting in reduced interfacial compatibility, uneven dispersion and agglomeration of the filler, blockage of micropores, reduction of gas adsorption capacity, specific surface area and pore volume, deterioration of pore size distribution, reduction of interfacial bonding strength, decrease of mechanical properties, and increased gas release due to damage to pore structure integrity.

[0089] In Comparative Example 2, since hydroxyethyl acrylate was not used to modify the polyetheramine, the curing agent molecule lacked hydroxyl synergistic active sites, the epoxy-amine crosslinking density was reduced, the organic-inorganic interpenetrating network was not dense enough, the anchoring effect of the matrix on the inorganic filler was weakened, resulting in a significant reduction in mechanical properties, limited pore accessibility, reduced gas adsorption capacity, and increased outgassing.

[0090] In Comparative Example 3, since bisphenol A type epoxy resin was used to replace titanium-silicon hybrid sol, the system lacked Ti-O-Si inorganic network and Ti(IV) coordination unsaturated active sites, resulting in reduced chemical adsorption capacity. The microporous structure shrank and collapsed during high-temperature curing and activation, significantly reducing the specific surface area and pore volume, and deteriorating the pore size distribution. At the same time, the gas efflux rate of the traditional epoxy resin matrix increased, and the vacuum stability decreased. Both the overall adsorption performance and structural stability declined.

[0091] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a gas-absorbing composite material with high adsorption capacity, characterized in that, Includes the following steps: S1. Place the hybrid sol, epoxy silane-grafted UiO-66 and modified polyetheramine curing agent in a reaction vessel and stir. Heat the reaction vessel to 25-35℃, keep it warm and stir for 30-60 minutes, and then process it to obtain the air-absorbing composite slurry. S2. Pour the air-absorbing composite slurry into a polytetrafluoroethylene mold, transfer it to a vacuum drying oven protected by nitrogen atmosphere at a temperature of 60-80℃ and cure for 2-4 hours, then raise the temperature to 105-115℃ and cure for 2-4 hours. After crushing, sieve to obtain air-absorbing composite particles. S3. The air-absorbing composite particles are subjected to segmented heating, vacuum degassing, and post-curing to obtain the air-absorbing composite material.

2. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, In step S1, the weight ratio of the hybrid sol, epoxy silane grafted UiO-66, and modified polyetheramine curing agent is 100:15-25:15-25.

3. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, In step S2, the sieving is for collecting particles with a diameter of 20-60 μm.

4. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, In step S3, the specific steps of segmented heating, vacuum degassing, and post-curing are as follows: the gas-absorbing composite particles are placed in a vacuum chamber with a vacuum degree ≤10Pa, and the temperature is first increased to 120-130℃ at 1-2℃ / min and kept at that temperature for 2-3h. Then, the temperature is increased to 180-220℃ at 2-3℃ / min and kept at that temperature for 4-6h to obtain the gas-absorbing composite material.

5. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, The hybrid sol was prepared by the following steps: A1. Place tetrabutyl titanate, acetylacetone and xylene in a reaction vessel under nitrogen atmosphere protection, stir at room temperature for 15-25 min to obtain acetylacetone chelated tetrabutyl titanate pre-modified solution. A2. Place 3-(2,3-epoxypropoxy)propyltrimethoxysilane, deionized water and ethanol in a reaction vessel and stir. Add an aqueous acetic acid solution, heat the reaction vessel to 45-55℃ and keep it at that temperature for 2-4 hours. Cool the reaction vessel to 30-40℃, add acetylacetone chelated tetrabutyl titanate pre-modified solution, stir at room temperature for 30-60 minutes, remove low-boiling substances by vacuum distillation, heat the reaction vessel to 105-115℃ and keep it at that temperature for 3-5 hours. Post-treatment yields a hybrid sol.

6. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 5, characterized in that, In step A1, the ratio of tetrabutyl titanate, acetylacetone, and xylene is 45-55g:8-12g:35-45mL; in step A2, the ratio of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, deionized water, ethanol, aqueous acetic acid solution, and acetylacetone chelated tetrabutyl titanate pre-modified solution is 40-60g:6-8mL:50-70mL:4-7mL:38-58g, and the concentration of the aqueous acetic acid solution is 1-3wt%.

7. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, The modified polyetheramine curing agent is prepared by: placing polyetheramine and ethanol in a reaction vessel under nitrogen atmosphere and stirring, heating the reaction vessel to 40-50℃, adding hydroxyethyl acrylate, heating the reaction vessel to 55-65℃, maintaining the temperature for 4-6 hours, and then performing post-treatment to obtain the modified polyetheramine curing agent.

8. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 7, characterized in that, The ratio of polyetheramine, ethanol and hydroxyethyl acrylate is 85-95g:80-120mL:15-25g.

9. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, The preparation method of the epoxy silane grafted UiO-66 is as follows: UiO-66 and toluene are placed in a reaction vessel under nitrogen atmosphere protection and dispersed at room temperature for 30-40 min. Then, 3-(2,3-epoxypropoxy)propyltrimethoxysilane is added, the reaction vessel is heated to 60-70℃, and the reaction is maintained for 4-6 h. After post-treatment, epoxy silane grafted UiO-66 is obtained.

10. The method for preparing a high-adsorption-capacity gas-getting composite material according to claim 1, characterized in that, The ratio of UiO-66, toluene, and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 5-10g:40-60mL:3-5g.

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