Oligomeric urea-amine molecule, preparation and application in carbon dioxide adsorption

Abstract

The invention relates to oligomeric urea-amine molecules, preparation and application in carbon dioxide adsorption, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: firstly, reacting an amino-containing compound with p-nitrophenyl chloroformate to generate carbamate with a specific structure, and then reacting carbamate with hydrazine hydrate to combine amine groups in carbamate with hydrazine molecules in hydrazine hydrate to obtain oligomeric urea-amine molecules. The molecule has the characteristics of simple structure, excellent water solubility and high melting point, and can efficiently adsorb carbon dioxide; and after heating treatment at a relatively low temperature, desorption release of carbon dioxide can be realized, and regeneration of molecules can also be achieved.

Description

Technical Field

[0001] This invention relates to an oligourea-amine molecule, its preparation, and its application in carbon dioxide adsorption, belonging to the field of polymer materials technology. Background Technology

[0002] Effective carbon dioxide (CO2) capture is crucial for mitigating climate change, driving the search for materials with both high adsorption capacity and low regeneration energy consumption. Traditional chemisorbents (such as inorganic bases, organic amines, and their polymers or framework derivatives) typically rely on forming strong chemical bonds (such as carbonates or carbamates). While such strong bonds can effectively capture CO2, they often require a large energy input to release it. Hydrogen bonds, as a key secondary interaction, are increasingly prominent in regulating CO2 capture and release properties. Strategic modification of organic amine systems provides a prime example: by introducing intramolecular hydrogen bond donors or acceptors such as pyridine or amides at the ortho position of reactive amine groups (ACS Sustainable Chem. Eng. 2019, 7, 7535-7542), CO2 adducts (such as carbamates or carbamates) can be stabilized through internal hydrogen bonding. Such stabilization not only modulates the binding strength but also reduces regeneration energy by shifting the acid / zwitterionic balance towards more easily released neutral species, as has been demonstrated in aminopyridine solvents. In these systems, intramolecular hydrogen bonding networks are key to achieving low viscosity and reducing regeneration temperatures (down to 60-80°C). In aqueous media, the design principle shifts to utilizing strongly charge-assisted hydrogen bonds to capture these anions. The groundbreaking progress made by Custelcean et al. in the field of bisiminoguanidine compounds is pioneering (Angew. Chem. Int. Ed. 2017, 56, 1042–1045). Rigid planar guanidine units are readily protonated to form guanidine cations, which react with CO32-. 2- / HCO3 - Forming complementary strong hydrogen bonds, resulting in CO3 with low solubility. 2- / HCO3 -Complexes are used to remove carbon dioxide from the air. Notably, the adsorbent regeneration process, achieved by releasing carbon dioxide through gentle heating of solid carbonate crystals, can be completed at temperatures of 80-120°C, demonstrating how engineered hydrogen bond networks can achieve energy-efficient capture-release cycles. This research collectively reveals hydrogen bonds as a versatile and powerful design element that can be used to customize carbon dioxide capture materials. Similar to guanidine units, urea structures can also bind oxygen anions such as carbonate and bicarbonate ions via hydrogen bonds; however, there are currently no carbon dioxide capture materials based on urea structures. The inventors are attempting to extend this supramolecular strategy to urea adsorbents. For example, by directly integrating amine groups into the oligourea framework, the high desorption energy consumption of amine-based carbon dioxide adsorption could be addressed by utilizing hydrogen bonding to lower the molecular desorption temperature, achieving low-energy carbon dioxide desorption. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide an oligourea-amine molecule, its preparation, and its application in carbon dioxide adsorption. Through the synergistic adsorption of CO2 by the urea functional group and primary / secondary / tertiary amines, the secondary / tertiary amines can serve as CO2 adsorption sites. The adsorption is achieved by utilizing the urea functional group and the HCO3 formed after adsorption. - Hydrogen bonding between urethane esters can reduce the energy consumption of CO2 desorption. The molecule has the advantages of simple synthesis, high yield, and good water solubility.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows.

[0005] An oligourea-amine molecule, the molecular structure of which is:

[0006] ; Wherein, R is a primary amine group, a secondary amine group, or a tertiary amine group.

[0007] Preferably, R is one of the following groups: n is 2 or 3.

[0008] The present invention discloses a method for preparing oligourea-amine molecules, the method comprising the following steps: (1) Under a protective gas atmosphere, the amine-containing compound and triethylamine were dispersed in dichloromethane, and then p-nitrophenyl chloroformate was added. After the p-nitrophenyl chloroformate reacted completely, the mixture was filtered, washed, and dried to obtain the carbamate intermediate. (2) Under a protective gas atmosphere, hydrazine hydrate and triethylamine were dispersed in mixed solvent 1, and then a carbamate intermediate was added. After the carbamate intermediate reacted completely, the solvent was removed, and the product was dried to obtain a solid product. Wherein, the amine-containing compound is a primary amine, a primary amine or a tertiary amine protected by Boc; When the compound containing an amine group is a primary amine protected by Boc or a primary amine protected by Boc, the solid product obtained in step (2) is added to mixed solvent 2 to remove the Boc protecting group, and then filtered, washed and dried to obtain oligourea-amine molecules. When the amine-containing compound is a tertiary amine, the solid product obtained in step (2) is an oligourea-amine molecule.

[0009] Preferably, in step (1), the equivalent ratio of the amine-containing compound to p-nitrophenyl chloroformate is 1:1.2.

[0010] Preferably, in step (1), the amine-containing compound is N-Boc-ethylenediamine, N-Boc-propanediamine, N-Boc-N-methylethylenediamine, N-Boc-N-methylpropanediamine or N,N-dimethylethylenediamine.

[0011] Preferably, in step (1), the carbamate is one of the following structures: n is 2 or 3.

[0012] Preferably, in step (2), the equivalent ratio of the carbamate intermediate to hydrazine hydrate is 2:1.

[0013] Preferably, in step (2), the mixed solvent 1 is a mixed solvent of acetonitrile and tetrahydrofuran with a volume ratio of 1:1 to 1:2, or a mixed solvent of acetonitrile and acetone with a volume ratio of 1:1 to 1:2.

[0014] Preferably, in step (2), the mixed solvent 2 is a mixed solvent of trifluoroacetic acid and dichloromethane with a volume ratio of 1:1 to 1:2, or a mixed solvent of hydrochloric acid and dichloromethane with a volume ratio of 1:1 to 1:2.

[0015] The present invention relates to the application of an oligourea-amine molecule, wherein the oligourea-amine molecule is used as an adsorbent for adsorbing carbon dioxide.

[0016] Preferably, a carbon dioxide-containing mixed gas is passed into oligourea-amine molecules or an aqueous solution containing oligourea-amine molecules at a constant flow rate to achieve selective adsorption of carbon dioxide.

[0017] Preferably, after adsorption is complete, the oligourea-amine molecules that have adsorbed carbon dioxide or an aqueous solution containing oligourea-amine molecules are heated to desorb and release the carbon dioxide gas, while restoring the original properties of the oligourea-amine molecules, thus achieving regeneration and recycling.

[0018] Preferably, the volume fraction of carbon dioxide in the mixed gas is 5% to 20%.

[0019] Preferably, the constant flow rate of the mixed gas is 20~100 Sccm.

[0020] Preferably, the concentration of the aqueous solution containing oligourea-amine molecules is 1~3 mol / L.

[0021] Preferably, the heating temperature is less than 100°C.

[0022] Beneficial effects This invention provides an oligourea-amine molecule with simple structure, excellent water solubility, and high melting point, enabling efficient adsorption of carbon dioxide. Furthermore, after heating at a relatively low temperature, it achieves both carbon dioxide desorption and release, and molecule regeneration. The adsorption and desorption mechanism is as follows: First, the amine group in the molecule reacts with carbon dioxide to generate bicarbonate ions or carbamate ions. Second, the urea group in the molecule combines with the generated bicarbonate ions or carbamate ions through hydrogen bonding, forming an unstable hydrogen bond network. Finally, heating the system breaks this unstable hydrogen bond network, thereby promoting the desorption and release of carbon dioxide.

[0023] This invention provides a method for preparing oligourea-amine molecules. First, an amine-containing compound reacts with p-nitrophenyl chloroformate to generate a carbamate with a specific structure. Then, the carbamate reacts with hydrazine hydrate to combine the amine groups in the carbamate with the hydrazine molecules in the hydrazine hydrate, yielding the oligourea-amine molecules. This preparation method is simple, efficient, and has good versatility; after the reaction, only simple filtration and separation are required to obtain oligourea-amine molecules with different structures in yields of over 60%.

[0024] This invention provides an application of an oligourea-amine molecule. The synergistic effect of the urea hydrogen bond donor and the amine promotes the direct capture of carbon dioxide. Compared with traditional amine adsorbents, the key breakthrough lies in the low desorption energy consumption during the carbon dioxide release process, highlighting the extremely low energy required to disrupt the unstable hydrogen bond network. This molecule maintains its complete capture capacity through multiple cycles, exhibiting excellent recyclability, and can be used to develop novel low-energy carbon capture materials suitable for practical humid environments. Attached Figure Description

[0025] Figure 1 This is a simplified diagram of the liquid phase adsorption device described in Example 8.

[0026] Figure 2 The diagram shows the solid-phase adsorption device described in Example 9.

[0027] Figure 3 The image shows the nuclear magnetic resonance spectrum changes during the heating process of the molecular aqueous solution after adsorbing carbon dioxide as described in Example 10.

[0028] Figure 4 This is a thermogravimetric curve of the molecular solid after adsorbing carbon dioxide, as described in Example 10. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to specific embodiments.

[0030] Example 1 Step 1: Under a nitrogen atmosphere, a mixed solution of anhydrous dichloromethane (50 mL) and triethylamine (3 mL) was added to a three-necked flask. N-Boc-ethylenediamine (1.0 g, 6.3 mmol, 1.0 equiv.) was then added using a syringe. Next, solid p-nitrophenyl chloroformate (1.5 g, 13.56 mmol, 1.2 equiv.) was added. The reaction was allowed to proceed at room temperature for 12 h. After the reaction was stopped, the mixture was filtered under reduced pressure through a sintered glass funnel, washed with solvent, and dried under vacuum to obtain intermediate S1.

[0031] Step 2: Under a nitrogen atmosphere, a mixed solution of anhydrous acetonitrile (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Hydrazine hydrate (0.1 g, 1.6 mmol, 1.0 equiv.) was added to the flask using a syringe. Then, solid S1 (0.9 g, 3.2 mmol, 2.0 equiv.) was added. The reaction was carried out at 70 °C for 12 h. After stopping the reaction, the solvent was removed by rotary evaporation under reduced pressure, and the solid was dried to obtain a pale yellow solid. The obtained pale yellow solid was dissolved in a mixed solvent of dichloromethane and trifluoroacetic acid to remove the BOC protecting group. The obtained solid was filtered, washed with a small amount of acetonitrile, and dried to obtain an oligourea-amine molecule L. 1 .

[0032] The reaction equation is: .

[0033] Example 2 Step 1: Under a nitrogen atmosphere, a mixed solution of anhydrous dichloromethane (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Using a syringe, N-Boc-propanediamine (1.0 g, 5.7 mmol, 1.0 equiv.) was added to the flask. Then, solid p-nitrophenyl chloroformate (1.38 g, 6.9 mmol, 1.2 equiv.) was added. The reaction was allowed to proceed at room temperature for 12 h. After the reaction was stopped, the mixture was filtered under reduced pressure through a sintered glass funnel, washed with solvent, and dried under vacuum to obtain intermediate S2.

[0034] Step 2: Under a nitrogen atmosphere, a mixed solution of anhydrous acetonitrile (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Hydrazine hydrate (0.1 g, 1.6 mmol, 1.0 equiv.) was added to the flask using a syringe. Then, solid S2 (0.95 g, 3.2 mmol, 2.0 equiv.) was added. The reaction was carried out at 70 °C for 12 h. After stopping the reaction, the solvent was removed by rotary evaporation under reduced pressure, and the solid was dried to obtain a pale yellow solid. The obtained pale yellow solid was dissolved in a mixed solvent of dichloromethane and trifluoroacetic acid to remove the BOC protecting group. The obtained solid was filtered, washed with a small amount of acetonitrile, and dried to obtain an oligourea-amine molecule L. 2 .

[0035] The reaction equation is: .

[0036] Example 3 Step 1: Under a nitrogen atmosphere, a mixed solution of anhydrous dichloromethane (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Then, N-Boc-N-methylethylenediamine (1.0 g, 5.7 mmol, 1.0 equiv.) was added to the flask using a syringe. Next, solid p-nitrophenyl chloroformate (1.38 g, 6.9 mmol, 1.2 equiv.) was added. The reaction was allowed to proceed at room temperature for 12 h. After the reaction was stopped, the mixture was filtered under reduced pressure through a sintered glass funnel, washed with solvent, and dried under vacuum to obtain intermediate S3.

[0037] Step 2: Under a nitrogen atmosphere, a mixed solution of anhydrous acetonitrile (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Hydrazine hydrate (0.1 g, 1.6 mmol, 1.0 equiv.) was added to the flask using a syringe. Then, solid S3 (1.0 g, 3.2 mmol, 2.2 equiv.) was added. The reaction was carried out at 70 °C for 12 h. After stopping the reaction, the solvent was removed by rotary evaporation under reduced pressure, and the solid was dried to obtain a pale yellow solid. The obtained pale yellow solid was dissolved in a mixed solvent of dichloromethane and trifluoroacetic acid to remove the BOC protecting group. The obtained solid was filtered, washed with a small amount of acetonitrile, and dried to obtain an oligourea-amine molecule L. 3 .

[0038] The final product L 3 The proton NMR results are as follows: one-dimensional proton NMR (Bruker 500MHz, DMSO) d6, ppm): δ 7.60 (s, 1H), 6.31 (d, J = 5.7 Hz, 1H), 3.08 (q, J= 6.0 Hz, 2H), 2.50 (dt, J = 3.7, 1.6 Hz, 5H), 2.26 (s, 3H). The reaction equation is: .

[0039] Example 4 Step 1: Under a nitrogen atmosphere, a mixed solution of anhydrous dichloromethane (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Then, N-Boc-N-methylpropanediamine (1.0 g, 5.3 mmol, 1.0 equiv.) was added to the flask using a syringe. Next, p-nitrophenyl chloroformate solid (1.28 g, 6.4 mmol, 1.2 equiv.) was added. The reaction was allowed to proceed at room temperature for 12 h. After the reaction was stopped, the mixture was filtered under reduced pressure through a sintered glass funnel, washed with solvent, and dried under vacuum to obtain intermediate S4.

[0040] Step 2: Under a nitrogen atmosphere, a mixed solution of anhydrous acetonitrile (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Hydrazine hydrate (0.1 g, 1.6 mmol, 1.0 equiv.) was added to the flask using a syringe. Then, S4 solid (1.2 g, 3.8 mmol, 2.4 equiv.) was added. The reaction was carried out at 70 °C for 12 h. After stopping the reaction, the solvent was removed by rotary evaporation under reduced pressure, and the solid was dried to obtain a pale yellow solid. The obtained pale yellow solid was dissolved in a mixed solvent of dichloromethane and trifluoroacetic acid to remove the BOC protecting group. The obtained solid was filtered, washed with a small amount of acetonitrile, and dried to obtain an oligourea-amine molecule L. 4 .

[0041] The final product L 4 The proton NMR results are as follows: one-dimensional proton NMR (Bruker 500MHz, DMSO) d6, ppm): δ 7.57 (s, 1H), 6.41 (s, 1H), 2.98 (s, 3H), 2.23 (s, 3H), 1.50 (s, 2H). The reaction equation is: .

[0042] Example 5 Step 1: Under a nitrogen atmosphere, a mixed solution of anhydrous dichloromethane (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Using a syringe, N,N-dimethylethylenediamine (1.0 g, 11.3 mmol, 1.0 equiv.) was added to the flask. Then, solid p-nitrophenyl chloroformate (2.73 g, 13.6 mmol, 1.2 equiv.) was added. The reaction was allowed to proceed at room temperature for 12 h. After the reaction was stopped, the mixture was filtered under reduced pressure through a sintered glass funnel, washed with solvent, and dried under vacuum to obtain intermediate S5.

[0043] Step 2: Under a nitrogen atmosphere, a mixed solution of anhydrous acetonitrile (50 mL) and triethylamine (3 mL) was added to a three-necked flask. Hydrazine hydrate (0.1 g, 1.6 mmol, 1.0 equiv.) was then added using a syringe. S4 solid (0.86 g, 3.8 mmol, 2.4 equiv.) was then added. The reaction was carried out at 70 °C for 12 h. After the reaction was stopped, the mixture was filtered under reduced pressure through a sintered glass funnel, washed with solvent, and dried under vacuum to obtain intermediate L. 5 .

[0044] The final product L 5 The proton NMR results are as follows: one-dimensional proton NMR (Bruker 500MHz, DMSO) d6, ppm): δ 7.64 (s, 1H), 6.19 (s, 1H), 3.09 (q, J = 6.2 Hz, 3H), 2.27 (t, J = 6.5 Hz, 3H), 2.14 (s, 8H). The reaction equation is: .

[0045] Example 6 Molecular liquid phase adsorption of carbon dioxide, experimental method: To elucidate the CO2 capture mechanism, nuclear magnetic resonance (NMR) and mass spectrometry (MS) experiments were performed. When CO2 passes through an L-containing... 3 After ventilating the aqueous solution (20 mM) for approximately 30 minutes, CO2 adsorption was completed by observing the pH change. The resulting solution was then characterized by NMR and MS. 13 C10 NMR analysis showed that after adsorption, HCO3--attributed molecules appeared at 160 ppm (±0.5 ppm). - The signal was observed. In mass spectrometry, molecules interacting with HCO3 were observed. - The binding signal. NMR and mass spectrometry showed that the molecule could generate HCO3 after adsorption. -The urea group in the molecule reacts with HCO3. - There are hydrogen bond interactions between them.

[0046] L 1 L 2 L 4 L 5 The test results and L 3 similar.

[0047] Example 7 Molecular solid-phase adsorption of carbon dioxide, experimental method: To elucidate the CO2 capture mechanism, nuclear magnetic resonance (NMR), mass spectrometry (MS), and free-float infrared (FTIR) experiments were performed. When CO2 enters the L... 3 After ventilating the solid for approximately 30 minutes, the solid was then characterized by NMR, MS, and FTIR. 13 C10 NMR analysis revealed a signal attributed to urethane at 170 ppm (±1 ppm). Mass spectrometry showed the binding signal between the molecule and the urethane. FTIR characterization confirmed the presence of a urethane signal peak. Characterization indicates that the molecule can generate HCO3- after adsorption. - The urea group in the molecule reacts with HCO3. - There are hydrogen bond interactions between them.

[0048] L 1 L 2 L 4 L 5 The test results and L 3 similar.

[0049] Example 8 Measurement of carbon dioxide adsorption capacity in molecular liquid phase, experimental method: like Figure 1 As shown, 15 mL of simulated flue gas (10% CO2 / 90% N2) with a concentration of 20 mM L was introduced at room temperature. 3 In an aqueous solution, the adsorption process was monitored in real time using a device equipped with a high-precision CO2 sensor. The CO2 sensor recordings showed that the amount of captured CO2 gradually increased and reached a plateau within 50 minutes. The results indicated that the CO2 capacity of the molecule reached 1-2 mol / mol L.

[0050] L 1 L 2 L 4 L 5 The test results and L 3 similar.

[0051] Example 9 Measurement of carbon dioxide adsorption capacity in molecular solid-phase adsorption, experimental method: like Figure 2 As shown, simulated flue gas (10% CO2 / 90% N2) is introduced into L at room temperature. 3 The adsorption process was monitored in real time within the solid powder of the molecule using a device equipped with a high-precision CO2 sensor. The CO2 sensor recordings showed that the amount of captured CO2 gradually increased and reached a plateau within 15 minutes. The results indicated that the molecule's CO2 capacity was 0.3–0.6 mol / mol L.

[0052] L 1 L 2 L 4 L 5 The test results and L 3 similar.

[0053] Example 10 Study on the desorption temperature of carbon dioxide after adsorption in molecular liquid phase: After heating at 90℃ for 30 minutes, the L-type material treated with CO2 bubbling was... 3 The molecular solution (10 mM, D₂O) was analyzed by NMR, and the results are as follows: Figure 3 As shown. During the heating process, it was found that the hydrogen atoms on the molecular backbone all exhibited varying degrees of low-field shift. After heating for another 30 minutes, the signal completely transformed into a pure molecular signal, indicating that HCO3- - The anions have been completely released. During heating, the molecules reacted with HCO3-. - The hydrogen bond interactions were effectively disrupted, leading to the release of CO2 gas. This demonstrates that after adsorbing CO2, the molecule can release CO2 at temperatures below 90°C, lower than the release temperature of traditional secondary amine adsorbents (>100°C). Such low-temperature CO2 release phenomena are rarely reported, indicating that hydrogen bond interactions can serve as a tunable tool for regulating the capture and release process.

[0054] L 1 L 2 L 4 L 5 The test results and L 3 similar.

[0055] Example 10 Study on the desorption temperature of carbon dioxide after molecular solid-phase adsorption: CO2 captured by solid-phase adsorption (in the form of carbamate) can be easily released upon gentle heating, as confirmed by thermogravimetric analysis, with results as follows: Figure 4 As shown. After adsorption, L... 3When the solid is slowly heated, CO2 is released between 60-95℃, which is much lower than the release temperature of traditional secondary amine adsorbents (>100℃).

[0056] L 1 L 2 L 4 L 5 The test results and L 3 similar.

[0057] In summary, the invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered to be within the protection scope of this invention.

Claims

1. An oligourea-amine molecule, characterized in that: The molecular structural formula is: ； Wherein, R is a primary amine group, a secondary amine group, or a tertiary amine group.

2. The oligourea-amine molecule as described in claim 1, characterized in that: R is one of the following groups: n is 2 or 3.

3. A method for preparing the oligourea-amine molecule according to claim 1 or 2, characterized in that: The method steps include: (1) Under a protective gas atmosphere, the amine-containing compound and triethylamine were dispersed in dichloromethane, and then p-nitrophenyl chloroformate was added. After the p-nitrophenyl chloroformate reacted completely, the mixture was filtered, washed, and dried to obtain the carbamate intermediate. (2) Under a protective gas atmosphere, hydrazine hydrate and triethylamine were dispersed in mixed solvent 1, and then a carbamate intermediate was added. After the carbamate intermediate reacted completely, the solvent was removed, and the product was dried to obtain a solid product. Wherein, the amine-containing compound is a primary amine, a primary amine or a tertiary amine protected by Boc; When the compound containing an amine group is a primary amine protected by Boc or a primary amine protected by Boc, the solid product obtained in step (2) is added to mixed solvent 2 to remove the Boc protecting group, and then filtered, washed and dried to obtain oligourea-amine molecules. When the amine-containing compound is a tertiary amine, the solid product obtained in step (2) is an oligourea-amine molecule.

4. The method for preparing oligourea-amine molecules as described in claim 3, characterized in that: In step (1), the equivalent ratio of the amine-containing compound to p-nitrophenyl chloroformate is 1:1.2; Preferably, in step (1), the amine-containing compound is N-Boc-ethylenediamine, N-Boc-propanediamine, N-Boc-N-methylethylenediamine, N-Boc-N-methylpropanediamine or N,N-dimethylethylenediamine; Preferably, in step (1), the carbamate is one of the following structures: n is 2 or 3.

5. The method for preparing oligourea-amine molecules as described in claim 3, characterized in that: In step (2), the equivalent ratio of the carbamate intermediate to hydrazine hydrate is 2:1; Preferably, in step (2), the mixed solvent 1 is a mixed solvent of acetonitrile and tetrahydrofuran with a volume ratio of 1:1 to 1:2, or a mixed solvent of acetonitrile and acetone with a volume ratio of 1:1 to 1:

2. Preferably, in step (2), the mixed solvent 2 is a mixed solvent of trifluoroacetic acid and dichloromethane with a volume ratio of 1:1 to 1:2, or a mixed solvent of hydrochloric acid and dichloromethane with a volume ratio of 1:1 to 1:

2.

6. The application of the oligourea-amine molecule according to claim 1 or 2, characterized in that: The oligourea-amine molecules are used as adsorbents for adsorbing carbon dioxide.

7. The application of an oligourea-amine molecule as described in claim 6, characterized in that: A mixture of gases containing carbon dioxide is passed into oligourea-amine molecules or an aqueous solution containing oligourea-amine molecules at a constant flow rate to achieve selective adsorption of carbon dioxide. After adsorption is complete, the oligourea-amine molecules that have adsorbed carbon dioxide or the aqueous solution containing oligourea-amine molecules are heated to desorb and release the carbon dioxide gas, while restoring the original properties of the oligourea-amine molecules, thus achieving regeneration and recycling.

8. The application of an oligourea-amine molecule as described in claim 6, characterized in that: The volume fraction of carbon dioxide in the mixed gas is 5% to 20%; the constant flow rate of the mixed gas is 20 to 100 Sccm.

9. The application of an oligourea-amine molecule as described in claim 6, characterized in that: The concentration of the aqueous solution containing oligourea-amine molecules is 1~3 mol / L.

10. The application of an oligourea-amine molecule as described in claim 6, characterized in that: Heating temperature is less than 100℃.

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