A liquid mixture that absorbs carbon dioxide is used in polyurethane foam

Abstract

The invention discloses a liquid mixture capable of absorbing CO2, characterized in that the mixture is composed of a polyamine compound and a solvent; the mass percentage of the polyamine compound is 5% to 70%; the polyamine compound at least comprises a polyamine polymer and / or a grafted polyamine polymer, the polyamine polymer is a polymer containing 4 or more amine groups in the molecular chain, the atoms connected to the amine groups are carbon atoms, the structure is at least one of straight chain, branched, and hyperbranched, and the molecular weight is greater than 140; the solvent is composed of an alcohol with a carbon number of ≤5 and 2 or 3 hydroxyl groups and water, and the amount of water is 0 to 40% of the total mass of the solvent. After the liquid mixture capable of absorbing CO2 absorbs CO2, a foaming mixture capable of releasing CO2 is obtained, which is used for polyurethane foaming.

Description

Technical Field

[0001] The invention relates to the technical field of foaming agents, and in particular to a liquid foaming agent capable of absorbing a liquid mixture of carbon dioxide (CO2). Background Art

[0002] Polyurethane foam is widely used in sofas, mattresses, car seat cushions, refrigerators, pipes and building insulation. Generally speaking, the production of polyurethane foam often requires a large amount of foaming agents. Traditional foaming agents are low-boiling chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) compounds, which contain chlorine atoms in their structure and will destroy the ozone layer. The foaming agents currently used include hydrofluorocarbon (HFC) compounds and fluorinated olefin (HFO) compounds that do not contain chlorine and do not destroy the ozone layer. However, the former has a strong greenhouse effect and is one of the culprits of global warming. The latter's decomposition products in the atmosphere contain trifluoroacetic acid (CF3COOH) and hydrofluoric acid (HF), which may cause acid pollution and damage the ecological environment. Common foaming agents also include alkane foaming agents (such as cyclopentane). The performance of this type of foaming agent is similar to that of HFO. Although it has a smaller impact on the environment, it has the risk of being flammable and explosive.

[0003] An adduct is formed by the reaction of a polyamine polymer and CO2, and the adduct can release CO2 when heated for polyurethane foaming. The advantage of this foaming agent is that CO2 can be fixed in the polyamine polymer at room temperature and can be mixed with polyurethane raw materials, overcoming the disadvantage that gaseous CO2 is difficult to store in the foaming raw materials. During the polyurethane foaming process, the foaming agent absorbs the heat of reaction and releases CO2 for foaming. This type of foaming agent is solid and difficult to disperse in the polyurethane raw materials. Chinese patent CN 103965470 A discloses a CO2 adduct foaming agent of hydrophobically modified polyethyleneimine, and the hydrophobic chain used is a polypropylene glycol chain or an alkyl chain. The hydrophobic modification improves the dispersibility of the foaming agent in the polyurethane raw materials to a certain extent. Chinese patent CN 112457520A uses a mixture of hydrophobically modified polyethyleneimine and polyether polyol, and then absorbs CO2 to generate a CO2 adduct foaming agent of hydrophobically modified polyethyleneimine in situ, and the foaming agent is present in the polyether polyol in the form of nanoparticles. This method greatly improves the dispersibility of the foaming agent, but also increases the viscosity of the foaming mixture, causing inconvenience in use; excessively high viscosity may hinder the growth of bubbles and even cause bubble rupture, leading to foaming failure.

[0004] In fact, traditional polyurethane foaming agents are all liquid, which can be easily mixed with other liquid raw materials for foaming. Existing CO2 adduct foaming agents are all solid, which is very inconvenient to use. The development of liquid CO2 adduct foaming agents can not only retain the environmentally friendly characteristics of CO2 adduct foaming agents, but also increase the convenience of construction. Summary of the invention

[0005] The inventors of the present invention have actively sought for solvents for the existing CO2 adduct foaming agents of polyamine polymers, which are inconvenient to use, in the hope of developing a liquid CO2 adduct foaming agent system. The foaming agent is a CO2 adduct, which contains zwitterions (hydrophilic structures) composed of alkylammonium cations and carbamate anions in its molecular structure, and it is difficult for general organic solvents to dissolve the foaming agent. Water can dissolve the CO2 adduct of polyamine polymers. However, water itself is also a foaming agent for polyurethane. Introducing too much water will cause a large number of urea bonds to be generated in the generated polymer structure, and the foam will become brittle. At the same time, the coexistence of water and the CO2 adduct foaming agent of polyamine polymers in a system will bring constraints to the foam formula design. For example, in order to obtain low-density foam, it is necessary to increase the amount of foaming agent; if there is water in the foaming agent, the amount of water will inevitably be increased, and the increase in water will increase the amount of isocyanate, making the foam brittle. In other words, it is difficult to prepare low-density and soft foam. In addition, in general, CO2 adduct foaming agents of polyamine polymers need to be hydrophobically modified (in order to improve the dispersibility of the foaming agent in the polyurethane raw material; at the same time, grafting modification will increase steric hindrance to avoid excessive reaction between the free amino groups formed after the polyamine polymer releases CO2 and isocyanate, which will lead to excessive cross-linking density of the foam and also cause the foam to become brittle). After hydrophobic modification, the solubility in water will decrease a lot. Therefore, it is not appropriate to use water alone as a solvent for CO2 adduct foaming agents of polyamine polymers.

[0006] The inventors carefully studied the molecular structure of the CO2 adduct of polyamine polymers and found that the alkyl ammonium cations and carbamate anions contained in the structure can form hydrogen bonds, so they actively explored the feasibility of using hydroxyl- and amino-containing compounds as solvents for the CO2 adduct of polyamine polymers. After a lot of exploration, it was found that alcohols with carbon atoms ≤5 and hydroxyl groups of 2 or 3 can dissolve the CO2 adduct of polyamine polymers. At the same time, the alcohol can react with isocyanate, one of the raw materials of polyurethane, to become a part of polyurethane foam products. Therefore, the alcohol dissolves the CO2 adduct foaming agent of polyamine polymers (i.e., the CO2 adduct foaming agent of polyamine polymers) on the one hand, so that the foaming agent can be fully mixed with the liquid polyurethane raw material and play the role of foaming agent in the foam preparation process; at the same time, the alcohol can also react with isocyanate to play the role of chain extender and finally become a part of foam material. For this reason, the present invention proposes to mix the polyamine polymer and the alcohol to form a mixture that can absorb CO2, and then use it for polyurethane foaming after absorbing CO2.

[0007] One of the purposes of the present invention is to provide a liquid mixture capable of absorbing CO2, characterized in that the mixture consists of a polyamine compound and a solvent; the mass percentage of the polyamine compound is 5% to 70%; the polyamine compound at least comprises a polyamine polymer and / or a grafted polyamine polymer, the polyamine polymer is a polymer containing 4 or more amine groups in the molecular chain, the atoms connected to the amine groups are carbon atoms, the structure is at least one of straight chain, branched, and hyperbranched, and the molecular weight is greater than 140; the solvent is composed of an alcohol having a carbon atom number ≤5 and a hydroxyl group of 2 or 3 and water, and the amount of water used is 0 to 40% of the total mass of the solvent, preferably less than 10%.

[0008] The polyamine compound may also contain alcohol amines and polyamines with 2 to 5 hydroxyl and amino groups and ≤6 carbon atoms, including but not limited to ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, diglycolamine, ethanolamine, diethanolamine, triethanolamine, butanediamine, and diethylenetriamine; the amount of the alcohol amine and polyamine does not exceed 20% of the total mass of the polyamine compound; these small molecule polyamines can also absorb CO2 and form CO2 adducts with polyamine polymers and / or grafted polyamine polymers for foaming. After releasing CO2, the CO2 adducts of these small molecule polyamines will eventually react with isocyanates and become part of the foam. The amount of the polyamine should not be too much, otherwise the resulting polyurethane foam will become brittle due to excessive crosslinking density.

[0009] The polyamine polymer includes but is not limited to at least one of polyethyleneimine, polypropyleneimine, polybutyleneimine, polyethyleneamine, and polyallylamine; the grafted polyamine polymer may be grafted with at least one of the following side chains:

[0010] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1;

[0011] (2) The side chain contains a trimethylsilyl group;

[0012] (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms;

[0013] (4) The side chain contains a fluorinated alkyl group having 1 to 22 carbon atoms.

[0014] Specifically, the grafted side chain can be a polyether oligomer such as polyethylene glycol, polypropylene oxide, polyoxetane and polytetrahydrofuran, or polysiloxane, containing at least one repeating unit, and the structure is exemplified as follows:

[0015]

[0016] Wherein m is at least 1, n is a positive integer from 1 to 4, and Q and T are connecting groups between the grafted side chain and the main chain of the polyamine polymer. The connecting groups Q and T are replaceable groups, and the groups that can be selected are:

[0017]

[0018] The grafted side chain of the grafted polyamine polymer may also contain silane, and its structure may be:

[0019]

[0020] T is a linking group between the side chain and the main chain of the polyamine polymer, and T can be:

[0021]

[0022] The grafted side chain of the grafted polyamine polymer may also contain a hydrocarbon group with 1 to 22 carbon atoms and at least one unsaturated bond, and its structure is exemplified as follows:

[0023] C n H 2n-1 -M-,

[0024] Wherein n is an integer from 1 to 22, and M is a linking group between the hydrophobic side chain and the main chain of the polyamine polymer. The linking group M is a replaceable group, and M can be directly a covalent bond or an amide bond.

[0025] The grafted side chain of the grafted polyamine polymer may also contain an alkyl group or a fluorinated alkyl group having 1 to 22 carbon atoms, and its structure is exemplified as follows:

[0026] C n H 2n+1-m F m -M-,

[0027] Wherein n is an integer from 1 to 22, m is an integer from 0 or 1 to 43, and M is a linking group between the grafted side chain and the main chain of the polyamine polymer. The linking group M is a replaceable group, and M can be directly a covalent bond or an amide bond, and can also be selected from the following groups:

[0028]

[0029] It should be pointed out that the linking groups Q, T and M between the above-mentioned grafted side chains and the main chain of the polyamine polymer are all replaceable groups, and those skilled in the art can also select other groups for replacement, which are not listed here one by one.

[0030] As for the specific preparation method of the above-mentioned grafted polyamine polymer, the glycidyl ether with grafted side chains and the polyamine polymer can be reacted in an ethanol solution to obtain a grafted modified polyamine polymer. The structure of the glycidyl ether with a hydrophobic chain is:

[0031]

[0032] Wherein m is at least 1, n is a positive integer from 1 to 4, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is Q1; the structure of the glycidyl ether with a hydrophobic chain can also be:

[0033]

[0034] Wherein m is 0 or a positive integer, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is T; the structure of the glycidyl ether with a hydrophobic chain can also be:

[0035]

[0036] Wherein n is an integer from 1 to 22, m is an integer from 0 or 1 to 43, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is M2.

[0037] Alternatively, an alkyl group with an epoxy group or a fluorinated alkyl group with an epoxy group and a polyamine polymer may be reacted in an ethanol solution to obtain a grafted polyamine polymer. The structure of the alkyl group with an epoxy group or the fluorinated alkyl group may be:

[0038]

[0039] Wherein n is an integer from 1 to 22, m is an integer from 0 or 1 to 43, and the linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is M1.

[0040] The grafted polyamine polymer can also be prepared by the following method: first, the alkoxy polyether oligomer is reacted with iodoacetic acid and 2-bromoisocyanate to obtain a halogenated hydrocarbon-terminated product, and the reaction is as follows (wherein m is at least 1, and n is a positive integer from 1 to 4):

[0041]

[0042] The above reaction is based on an alkoxy polypropylene glycol oligomer as an example, wherein the repeating units may also be repeating units of polyethylene glycol, polyoxetane and polytetrahydrofuran.

[0043] Secondly, the above-mentioned halogenated hydrocarbon end-capping product is reacted with a polyamine polymer to remove the hydrogen halide to obtain N-substituted hydrophobic modified polyethyleneimine (the connecting group between the side chain and the main chain is Q2 or Q3).

[0044] The grafted polyamine polymer can also be prepared by reacting a bromide or iodide of an alkane or a fluorine-containing alkane with a polyamine polymer. The structure of the bromide or iodide can be:

[0045] C n H 2n+1-m F m -Br, or C n H 2n+1-m F m -I,

[0046] wherein n is an integer from 1 to 22, and m is an integer from 0 or 1 to 43. The linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is a covalent bond.

[0047] The grafted polyamine polymer can also be prepared by reacting an alkyl or fluorinated alkyl carboxylic acid with a polyamine polymer. The structure of the carboxylic acid can be:

[0048] C n H 2n+1-m F m -COOH,

[0049] wherein n is an integer from 1 to 22, and m is an integer from 0 or 1 to 43. The linking group between the side chain and the main chain of the grafted polyamine polymer prepared by this method is an amide bond.

[0050] The grafted polyamine polymer can also be prepared by reacting unsaturated fatty acids with polyamine polymers. The structure of the fatty acid can be:

[0051] C n H 2n-1 -M-,

[0052] wherein n is an integer from 1 to 22. The linking group M between the side chain and the main chain of the grafted polyamine polymer prepared by this method is an amide bond.

[0053] All these reactions are known chemical reactions, and their specific preparation methods can refer to existing disclosed technologies, such as patent document CN 108355472 A.

[0054] In addition, in the preparation method of the grafted polyamine polymer provided by the present invention, the grafting degree of the grafted polyamine polymer is 1 to 45 mol% based on the N atoms of the polyamine polymer. Preferably, the grafting degree of the grafted polyamine polymer is 3 to 20 mol% based on the N atoms of the polyamine polymer. Generally, the greater the grafting degree of the grafted polyamine polymer, the more conducive it is to dissolve in the solvent. However, if the grafting rate is too large, the number of amino groups of the grafted polyamine polymer that react with CO2 will decrease, and the CO2 content in the grafted polyamine polymer CO2 adduct will decrease, thereby reducing the foaming ability.

[0055] Specifically, the solvent in the liquid mixture capable of absorbing CO2 described in the present invention is at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butylene glycol, pentanediol, glycerol, ethanolamine, diethanolamine, triethanolamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, diethylene glycol, and diglycolamine; the butylene glycol is 1,4-butylene glycol or any isomer of 1,4-butylene glycol containing two hydroxyl groups, and the pentanediol is 1,5-pentanediol or any isomer of 1,5-pentanediol containing two hydroxyl groups. Among them, ethylene glycol has good solubility and is relatively cheap, and is often used as the preferred solvent. When ethylene glycol is mixed with other alcohols, a good dissolving effect can also be achieved. The other alcohols are at least one of 1,2-propylene glycol, 1,3-propylene glycol, glycerol, butanediol, pentanediol, and diethylene glycol; the butanediol, pentanediol, and hexanediol are any isomers of the corresponding diols containing two hydroxyl groups. When ethylene glycol is mixed with other small molecules containing hydroxyl groups and / or amino groups, the mass percentage of ethylene glycol is preferably not less than 50%.

[0056] It should be noted that the solvent in the liquid mixture capable of absorbing CO2 described in the present invention may include water, and the amount of water used does not exceed 40% of the total solvent mass. Water itself is also a chemical foaming agent for polyurethane materials, and water also has a certain dissolving effect. However, if the amount of water used is too large, it is not conducive to the dissolution of the CO2 adduct of the hydrophobic link grafted polyamine polymer obtained after absorbing CO2; at the same time, too much water will also cause the prepared foam to become brittle. The water content is preferably not more than 10%.

[0057] Another object of the present invention is to provide the use of the liquid mixture capable of absorbing CO2 for absorbing CO2 and obtaining a liquid foaming mixture containing CO2 adducts. The specific preparation process is: add the liquid mixture capable of absorbing CO2 into a reactor, introduce CO2 with a volume content of 1 to 100% into the reactor under stirring conditions, maintain the pressure in the reactor at 0 to 20 MPa, react for 0.1 to 72 hours, release the pressure to normal pressure, and obtain a "liquid foaming mixture containing CO2 adducts"; when the pressure is 0 MPa, it represents normal pressure, that is, equal to atmospheric pressure; in the above preparation process, the state of CO2 can be gas, liquid or supercritical. The supercritical state of CO2 is a state where the temperature is greater than 31.3 degrees Celsius and the pressure is greater than 7.4 MPa. In the above preparation process, if CO2 is liquid or in a supercritical state, pure CO2 must be used.

[0058] The preparation process of the above-mentioned "liquid foaming mixture containing CO2 adduct" can also be as follows: the above-mentioned liquid mixture that can absorb CO2 is transported to a pipeline reactor through a pressure pump, liquid or supercritical CO2 is added to the pipeline reactor through a metering pump, the two streams of reaction raw materials are fully mixed and reacted in a mixer, and are sprayed into the "liquid foaming mixture containing CO2 adduct" storage tank through a discharge port; the temperature of the material in the pipeline reactor is 0-50°C, and the pressure is such that CO2 can be kept in a liquid or supercritical state; the amount of CO2 added is 0.01-1.2 times the saturated absorption amount of the "polyamine compound" in the above-mentioned liquid mixture that can absorb CO2; when the amount of CO2 added is less than the saturated absorption amount, the product in the "liquid foaming mixture containing CO2 adduct" storage tank needs to pass through the pressure pump again or even multiple times to enter the pipeline reactor, and react with liquid or supercritical CO2 until the reaction of the liquid mixture that can absorb CO2 to CO2 reaches saturation.

[0059] Another object of the present invention is to provide a use of the liquid foaming mixture containing CO2 adduct obtained by absorbing CO2 with the liquid mixture capable of absorbing CO2 for preparing polyurethane foam. In the process of using the liquid foaming mixture containing CO2 adduct, other liquid components of polyurethane foam, such as foam leveling agent, catalyst, etc., can be added thereto in advance, which still falls within the protection scope of the present invention, because these additives themselves cannot dissolve the CO2 adduct, but only form a uniform mixture with the liquid foaming mixture.

[0060] Compared with the prior art, the present invention has the following positive effects:

[0061] 1. The liquid mixture capable of absorbing CO2 provided by the present invention can form a "liquid foaming mixture containing CO2 adduct" after absorbing CO2, which can be fully mixed with liquid polyurethane raw materials, thereby solving the problem that the CO2 adduct of solid polyamine polymer is difficult to disperse in polyurethane raw materials, and facilitating the application of the CO2 adduct of polyamine polymer as an environmentally friendly foaming agent in polyurethane foam.

[0062] 2. The solvent in the CO2 adduct liquid foaming agent containing polyamine polymer provided by the present invention contains hydroxyl groups in its molecular structure and can react with isocyanate to become a part of the foam structure, thus preventing the solvent from becoming a volatile substance to pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Attached Figure 1 The chemical structural formula of the side chain raw material used in preparing the grafted polyamine polymer in Examples (1) to (21) of the preparation of the grafted polyamine polymer. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical scheme and technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be noted that all these embodiments are for further illustrating the present invention and shall not be construed as limiting the present invention. Some non-essential improvements and adjustments made by those skilled in the art to the present invention according to the above-mentioned content of the present invention still belong to the protection scope of the present invention.

[0065] Preparation Example of Grafted Polyamine Polymer

[0066] Before describing the specific embodiments, the preparation of the grafted polyamine polymer of the present invention is first described. The polyamine polymer of the present invention is a polymer containing amino groups in the molecular structure, including but not limited to polyethyleneimine (PEI), polypropyleneimine (PPI), polybutyleneimine (PBI), and its molecular structure is respectively 2, 3, 4 methylene groups between amino groups, and of course polyamine polymers with 5 or 6 methylene groups are also possible (these polyalkyleneamines can have linear, branched and hyperbranched structural changes), but the more methylene groups there are, the less amino group content that absorbs CO2, and the foaming ability of the foaming agent per unit mass is reduced. In addition, polyamine polymers containing primary amine groups such as polyethyleneamine (PEA) and polyallylamine (PAA) can also be used. Its structure is shown below:

[0067]

[0068] The polyamine polymer of the present invention may be grafted with side chains to increase the dispersibility of its CO2 adduct in the polyurethane raw material, and the side chains include but are not limited to at least one of the following:

[0069] (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1;

[0070] (2) The side chain contains a trimethylsilyl group;

[0071] (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms;

[0072] (4) The side chain contains a fluorinated alkyl group having 1 to 22 carbon atoms.

[0073] The grafting degree of the grafted side chains can be varied as required, and can be varied between 1% and 45%.

[0074] Specifically, the structure of the synthesized grafted modified polyamine polymer is shown in Table 1. The theoretical grafting degree is calculated by the molar ratio of the amino groups grafted with side chains to all the amino groups on the main chain, and the actual grafting degree is calculated by the area ratio of the proton signals related to the side chains and the main chain in the nuclear magnetic resonance spectrum. It should be noted that the sample code in the table is composed of the codes of the side chain and the polyamine polymer, such as 5% C8-PEI, wherein 5% C8 means that the side chain is an alkyl chain containing 8 carbon atoms, 5% means the designed grafting degree of the side chain (i.e., the theoretical grafting degree), PEI means that the polyamine polymer is polyethyleneimine, and the source of the side chain is C8-EPO, and its structure is shown in Figure 1 The codes of other samples have similar meanings. Some samples have two grafted side chains, and the theoretical grafting degree and side chain code of each side chain are listed separately. The sources of all side chains are listed in Figure 1 The code names of polyamine polymers are: PEI polyethylene imine, PPI polypropylene imine, PBI polybutylene imine, PEA polyethylene amine, PAA polyallyl amine. Except for PEA and PAA, the other polyamine polymers have linear, branched or hyperbranched structural variations.

[0075] Table 1

[0076]

[0077]

[0078] The process conditions and steps of the preparation examples (1) to (16), (20) and (21) of the grafted polyamine polymer are as follows: the corresponding polyamine polymer is added to a reaction kettle, and ethanol is added to the reaction kettle to make the mass concentration of the polyamine polymer about 10%, the polyamine polymer is completely dissolved under stirring, and then the corresponding glycidyl ether compound (Table 1, side chain raw material) is added to make the theoretical grafting degree of the side chain conform to the value listed in Table 1, the reaction is stirred at 50°C for 15 hours, and then the ethanol is removed by rotary evaporation; first, 10 parts by volume of petroleum ether is added to the product after rotary evaporation to dissolve the product and unreacted glycidyl ether compounds, and then 1 / 3 of the volume of petroleum ether is added to distilled water to precipitate the grafted modified polyamine polymer; the precipitated polyamine polymer is then washed with petroleum ether for at least three times, and then the petroleum ether is removed by rotary evaporation and dried to constant weight to obtain the product.

[0079] The process conditions and steps of the preparation of the graft modified polyamine polymer raw material (17) are as follows: 1 mol of polyethyleneimine measured by the repeating unit of polyethyleneimine is dissolved in chloroform to a mass concentration of about 10%, and then 0.03 mol of C 17 H 33 -COOH( Figure 1 ) and N,N'-carbonyldiimidazole (CDI), the theoretical grafting rate is 3%. Then the reaction is stirred under reflux for 12 hours, extracted with saturated brine three times, the chloroform layer is taken, the solvent is removed by rotary evaporation at 50°C, and finally dried in an oven at 75°C to obtain a purified hydrophobic link grafted polyethyleneimine product 3% C 17 H 33 -PEI.

[0080] The process conditions and steps of the preparation example (18) of the graft modified polyamine polymer raw material are as follows: 1 mol of polyethyleneimine measured by the repeating unit of polyethyleneimine is dissolved in chloroform to a mass concentration of about 10%, and then 0.2 mol of C2F3-I (Table 1) is added and refluxed for 3 hours.

[0081] The reaction mixture was cooled to room temperature, extracted three times with an equal volume of 5% aqueous sodium hydroxide solution and chloroform, the aqueous layer was removed, washed with water until the pH value of the aqueous layer was neutral, the organic layer was dried with anhydrous sodium sulfate, and the solvent was removed by vacuum rotary evaporation at 40°C to obtain the corresponding hydrophobic chain-modified polyethyleneimine 20% C2F3-PEI.

[0082] The process conditions and steps of the preparation example (19) of the grafted polyamine polymer raw material are as follows: 1 mol of polyethyleneimine measured on the basis of the repeating unit of polyethyleneimine is dissolved in chloroform to a mass concentration of about 10%, and then 0.45 mol of C4-Br (Table 1) is added, and the mixture is refluxed for 6 hours, cooled to room temperature, and the reaction mixture is extracted three times with a 5% aqueous sodium hydroxide solution having an equal volume to that of chloroform.

[0083] The aqueous layer was removed and washed with water until the pH value of the aqueous layer was neutral. The organic layer was dried with anhydrous sodium sulfate and the solvent was removed by vacuum rotary evaporation at 40° C. to obtain the corresponding hydrophobic chain-modified polyethyleneimine 45% C4-PEI.

[0084] It can be seen from Table 1 that the actual grafting degree of each product is very close to the theoretical grafting degree, indicating that the grafting reaction is very complete. The theoretical grafting degree is calculated by the ratio of the molar number of the side chain to the molar number of the main chain nitrogen atoms, and the actual grafting degree is calculated by the area ratio of the proton signals related to the side chain and the main chain in the nuclear magnetic resonance spectrum. It can be seen from Table 1 that the grafting degree of the hydrophobic chain of each product is between 1 and 45%.

[0085] Examples 1 to 37

[0086] In this group of examples, grafted polyamine polymers (see Table 1) and / or polyamine polymers, polyamine compounds composed of alcoholamines and polyamines, and solvents are prepared into a liquid mixture capable of absorbing CO2 (see Table 2).

[0087] Table 2

[0088]

[0089]

[0090] It should be pointed out that although the butanediol and pentanediol in Table 2 are straight-chain diols and the butanediamine is a straight-chain diamine, it is also possible to use the corresponding diols or diamines with branches instead. In Table 2, when the solvent contains two or more components, the value after each component represents the mass percentage of the component in the total solvent. In particular, water can account for 40%, preferably less than 10%. If the polyamine compound in Table 2 contains alcoholamines and / or polyamines, the names of the corresponding alcoholamines and polyamines are listed, and the values ​​after the names represent the mass percentage of the component in the polyamine compound, and the amount of alcoholamines and polyamines does not exceed 20% of the total mass of the polyamine compound. The values ​​in the last column of Table 2 represent the mass percentage of the total mass of the polyamine compound in the entire liquid mixture that can absorb CO2.

[0091] Application Examples 1-37

[0092] This group of application examples selects the liquid mixture capable of absorbing CO2 prepared in Examples 1-37 (see Table 2), and uses it to absorb CO2 to prepare a liquid foaming mixture containing CO2 adducts. The numbering of this group of application examples is related to the source of the liquid mixture capable of absorbing CO2. For example, if the liquid mixture capable of absorbing CO2 of Example 1 is used to prepare a liquid foaming mixture containing CO2 adducts, then the numbering of this application example is Application Example 1 (abbreviated as Application Example 1); if the liquid mixture capable of absorbing CO2 of Example 2 is used to prepare a liquid foaming mixture containing CO2 adducts, then the numbering of this application example is Application Example 2 (abbreviated as Application Example 2); and the numbers of the remaining application examples are analogous.

[0093] Application Examples 1-13 use a pipeline reactor to prepare a liquid foaming mixture containing CO2 adducts. 20 kg of the corresponding liquid mixture that can absorb CO2 is transported to the pipeline reactor through a pressure pump, and liquid or supercritical CO2 is added to the pipeline reactor through a metering pump. The two streams of reaction raw materials are fully mixed and reacted in the mixer, and sprayed into the "liquid foaming mixture containing CO2 adducts" storage tank through the discharge port; the temperature of the material in the pipeline reactor is 40°C and the pressure is 8MPa; the amount of CO2 added is 0.2 times the saturated absorption amount of the "polyamine compound" in the corresponding liquid mixture that can absorb CO2; the product in the "liquid foaming mixture containing CO2 adducts" storage tank needs to enter the pipeline reactor after 5 cycles to reach saturation, stop the reaction, and obtain the "liquid foaming mixture containing CO2 adducts". It should be noted that the saturated absorption capacity of the "polyamine compound" is calculated based on the absorption of one molecule of CO2 by two amino groups (including alcohol amines and polyamines, see Table 2) in the corresponding "polyamine compound". For example, the polyamine compound in Application Example 1 is 5% C8-PEI, with a mass of 5.16 kg. It is calculated that its saturated absorption of CO2 is 2.15 kg.

[0094] Application Examples 14-37 A reactor is used to prepare a liquid foaming mixture containing a CO2 adduct. The specific preparation process is as follows: 100 kg of the corresponding liquid mixture that can absorb CO2 is added to the reactor, pure CO2 is introduced into the reactor under stirring conditions, the pressure in the reactor is maintained at 2 MPa, the reaction is carried out for 72 hours, and the pressure is released to normal pressure to obtain a "liquid foaming mixture containing a CO2 adduct". When the pressure is just released, a small amount of bubbles can be observed in the obtained "liquid foaming mixture containing a CO2 adduct", indicating that the corresponding liquid mixture that can absorb CO2 has absorbed CO2 to saturation.

[0095] The liquid foaming mixtures containing CO2 adducts prepared in this group of application examples are all in a transparent liquid state.

[0096] Application Examples 38–42

[0097] This group of application examples selects the "liquid foaming mixture containing CO2 adduct" of application examples 1 to 37 as the foaming agent to prepare polyurethane foam, and the formula is shown in Table 3 (this formula is only used to illustrate the foaming effect of different foaming mixtures, and the foaming formula can be adjusted according to different purposes of use).

[0098] Table 3

[0099]

[0100] In Table 3, the polyester polyol is polybutylene adipate glycol ester (butanediol and ethylene glycol molar ratio 1:1), molecular weight of about 1500g / mol, hydroxyl value 76.2mgKOH / g, from Sigma; propylene glycol is from Chengdu Changlian Chemical Reagent Co., Ltd.; stannous octoate and triethylenediamine are from Chengdu High-end Polymer Technology Co., Ltd.; foam leveling agent BL-8530 is from Shanghai Maihao New Materials Technology Co., Ltd.; PM-200 is polymethylene polyphenyl isocyanate, from Wanhua Chemical Group Co., Ltd., and the isocyanate (NCO) content is 30.5-32.0%. The source 2 in the table refers to Application Example 2, and so on.

[0101] Polyurethane foams containing different foaming agents were prepared, and the formulas were shown in Table 3. Comparative Example 1 (referred to as Comparative Example 1) did not add any foaming agent, and foaming was performed by a trace amount of water in the raw materials. The foaming agent solution and other white material components were mixed according to the formula ratio, mechanically stirred at 800 r / min for 30 seconds, and then the black material was added, and then mechanically stirred at 1800 r / min for 15 seconds, and the foam was allowed to grow naturally. When the top of the foam was no longer sticky, the foaming was completed to obtain polyurethane foam.

[0102] Since the foaming agent in Table 3 is a "liquid foaming mixture containing CO2 adduct", it can be easily mixed with other components. The density of the foam prepared by application examples 38 to 42 is much lower than that of the control sample, indicating that the foaming agent does play a foaming role. Application example 42 adds 0.1 parts by mass of water as an additional foaming agent on the basis of application example 41 (water accounts for 10% of the ethylene glycol solvent in the foaming agent and 9.1% of the total amount of water and ethylene glycol). Since water consumes isocyanate, the amount of PM-200 is also increased accordingly. The density of application example 42 is further reduced, and the density is also lower than that of control sample 2 (vs. 2) using only water as a foaming agent, indicating that water and the foaming mixture of application example 12 play a foaming role together.

[0103] In Application Example 5, the foaming agent water is directly mixed with the foaming mixture of Example 12 to obtain a uniform foaming mixture. This shows that when the "liquid foaming mixture containing CO2 adduct" of the present invention is actually used, water can be added to the liquid foaming mixture of the present invention, and the added water also plays the role of a foaming agent. Such a use method also belongs to the protection scope of the present invention.

[0104] It should be pointed out that the polyurethane foam formula listed in the present invention is only to verify that the "liquid foaming mixture containing CO2 adduct" prepared by the present invention can be used for the preparation of polyurethane foam, and it cannot be understood as a limitation on the scope of use of the foaming agent material and solvent prepared by the present invention. The formation process of polyurethane foam is an exothermic reaction, and the heat released is just used to release the carbon dioxide in the foaming agent prepared by the present invention. Therefore, the foaming agent material and solvent system prepared by the present invention can be used in various polyurethane foams.

[0105] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A liquid mixture capable of absorbing CO2, characterized in that: The mixture consists of a polyamine compound and a solvent; the mass percentage of the polyamine compound is 5 to 70%; The polyamine compound at least comprises a grafted polyamine polymer, wherein the main chain of the grafted polyamine polymer is a polymer containing 4 or more amine groups, the atoms connected to the amine groups are carbon atoms, and the structure is at least one of linear, branched, and hyperbranched, and the molecular weight is greater than 500; the side chain of the grafted polyamine polymer is at least one of the following: (1) The side chain is polyethylene glycol, polypropylene oxide, polyoxetane, polytetrahydrofuran or polysiloxane, and the degree of polymerization is at least 1; (2) The side chain contains a trimethylsilyl group; (3) The side chain contains a hydrocarbon group having 1 to 22 carbon atoms; (4) The side chain contains a fluorinated alkyl group having 1 to 22 carbon atoms; The grafting degree of the grafted polyamine polymer is 1 to 45 mol% based on the N atoms of the polyamine polymer; The solvent is composed of alcohol with carbon atoms ≤5 and 2 or 3 hydroxyl groups and water, and the amount of water used is 0-40% of the total mass of the solvent.

2. The liquid mixture capable of absorbing CO2 according to claim 1, characterized in that: The amount of water used is 1-10% of the total mass of the solvent.

3. The liquid mixture capable of absorbing CO2 according to claim 1, characterized in that: The polyamine compound further comprises alcohol amine and polyamine with 2 to 5 hydroxyl groups and amino groups and 6 carbon atoms, and the amount of the alcohol amine and polyamine does not exceed 20% of the total mass of the polyamine compound.

4. The liquid mixture capable of absorbing CO2 according to claim 1, characterized in that: The solvent is at least one of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, butylene glycol, pentanediol, glycerol, and diethylene glycol; the butylene glycol is 1,4-butylene glycol or any isomer of 1,4-butylene glycol containing two hydroxyl groups; the pentanediol is 1,5-pentanediol or any isomer of 1,5-pentanediol containing two hydroxyl groups.

5. The liquid mixture capable of absorbing CO2 according to claim 1, characterized in that: The main chain of the grafted polyamine polymer includes polyethyleneimine, polypropyleneimine, polybutyleneimine, polyethyleneamine and polyallylamine.

6. The liquid mixture capable of absorbing CO2 according to claim 1, wherein the polypropylene oxide contains in, m is an integer of 1 to 15, n is an integer of 1 to 6; the polysiloxane chain contains Wherein, m is an integer of 0 to 10, T is a linking group between the polysiloxane chain and the main chain of the grafted polyamine polymer, and the structure of T is 7. Use of the liquid mixture capable of absorbing CO2 according to any one of claims 1 to 6, wherein the liquid mixture capable of absorbing CO2 is reacted with CO2 to obtain a liquid foaming mixture containing a CO2 adduct.

8. Use of the liquid mixture capable of absorbing CO2 according to any one of claims 1 to 6, wherein the liquid mixture capable of absorbing CO2 is reacted with CO2 to obtain a liquid foaming mixture containing a CO2 adduct, and the liquid foaming mixture is used for preparing polyurethane foam.

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