Covalent polymerization network material for adsorbing VOCs (Volatile Organic Compounds) and preparation method of covalent polymerization network material

Abstract

The invention discloses a covalent polymerization network material for adsorbing VOCs and a preparation method of the covalent polymerization network material. The covalent polymerization network material is formed by condensation polymerization of tetra (4-formyl phenyl) methane and polyether amine in an organic solvent. The covalent polymerization network material can be applied to the technical field of volatile gas pollutant treatment, the covalent polymerization network material is composed of a rigid benzene ring monomer and a flexible chain segment, the rigid monomer is beneficial to formation of a polymer pore channel for adsorbing gas, and the flexible chain segment is beneficial to temperature-controlled shrinkage and later waste gas release and material regeneration; according to the material, by adjusting the molecular weight of polyether amine, the pore diameter range of pore channels can be adjusted, and adsorption of organic matter of different sizes is facilitated; in addition, by adjusting the stoichiometric ratio of the monomers, the exposure degree of amino can be adjusted and controlled, and organic gas can be attracted into pore channels easily.

Description

Technical Field

[0001] The invention relates to environmental pollution control technology, and in particular to a covalent polymerization network material for absorbing multiple VOCs and a preparation method thereof. Background Art

[0002] Volatile organic gases (VOCs) are a class of organic compounds that exist in the air in the form of vapor at room temperature. According to their chemical structure, they can be divided into alkanes, halogenated hydrocarbons, aromatic hydrocarbons, olefins, organic ketones, amines, alcohols, ethers, esters, aldehydes and petroleum hydrocarbons. VOCs are ubiquitous in the ambient air indoors and outdoors. The emission of these pollutants not only causes a huge waste of resources, but also seriously pollutes the environment. Due to the complex composition of VOCs, they have certain toxicity, irritation and special odor. After entering the human body through the respiratory tract and skin, they will have an impact on human health. Therefore, the removal of VOCs has always been valued by all walks of life.

[0003] Imine covalent polymer networks are widely used in agro-industrial chemistry, pigments, catalysts, intermediates, polymer stabilizers, dyes, bioactive agents, molecular memory storage, imaging systems, medicine and other fields due to their ease of preparation, wide sources of raw materials, and the ease of coordination of lone pairs of electrons on nitrogen. It is a common method to prepare polyimine covalent polymer networks directly through the condensation reaction between aldehyde groups and amino groups. The properties of polyimine can be adjusted by the solvent used in the molding process and the monomer concentration. In addition, the density of imine bonds in polyimine is relatively high, and it is easy to have free amino groups in the network by controlling the stoichiometric ratio, which is conducive to attracting organic gases into the pores. Summary of the invention

[0004] The present invention aims to provide a covalent polymer network material for adsorbing VOCs and a preparation method thereof.

[0005] The technical solution of the present invention is as follows:

[0006] A covalent polymerized network material for absorbing VOCs is prepared by polycondensation of tetrakis(4-formylphenyl)methane and polyetheramine in an organic solvent; wherein the weight average molecular weight of the polyetheramine is 200-2000.

[0007] The method for preparing the covalently polymerized network material of the present invention comprises the following steps:

[0008] (1) adding tetrakis(4-formylphenyl)methane to an organic solvent and performing ultrasonic dispersion to obtain a solution A;

[0009] The organic solvent is selected from 1,4-dioxane, tetrahydrofuran or chloroform;

[0010] (2) adding polyetheramine to solution A, dispersing by ultrasonication, and then adding a catalyst to obtain solution B;

[0011] The molar ratio of the amino group contained in the polyetheramine to the aldehyde group contained in tetrakis(4-formylphenyl)methane is 1 to 1.5:1;

[0012] The catalyst is selected from one or more of acetic acid, scandium trifluoromethanesulfonate, trifluoromethanesulfonic acid, and p-toluenesulfonic acid; preferably acetic acid, and preferably fed in the form of an acetic acid aqueous solution;

[0013] (3) transferring solution B to a polytetrafluoroethylene reactor, reacting in a closed environment at 100 to 180° C. for 2 to 8 days, washing the resulting crude product with an organic solvent, and vacuum drying to obtain the covalently polymerized network material;

[0014] The organic solvent used for cleaning is selected from one or more of tetrahydrofuran, acetone, ethanol, 1,4-dioxane and chloroform.

[0015] In the above preparation method, "solution A" and "solution B" have no special meanings, and are marked as "A" and "B" only to distinguish the solutions in different operation steps.

[0016] The covalent polymer network material of the present invention can be used to adsorb VOCs. The specific method of use is:

[0017] The covalently polymerized network material is placed in an atmosphere containing an organic gas, column penetration adsorption is performed at the same gas flow rate, and the gas content and adsorption rate are monitored in real time using gas chromatography;

[0018] Organic gases such as styrene, octane, etc.

[0019] The beneficial effects of the present invention are:

[0020] 1. The present invention is applicable to the technical field of volatile gas pollutant treatment. The covalent polymer network material is composed of rigid benzene ring monomers and flexible segments. The rigid monomers are conducive to forming polymer channels for gas adsorption, and the flexible segments are conducive to temperature-controlled contraction, which is conducive to the later release of waste gas and material regeneration.

[0021] 2. The material of the present invention can adjust the pore size range by adjusting the molecular weight of the polyetheramine, which is conducive to the adsorption of organic matter of different sizes. In addition, by adjusting the stoichiometric ratio of the monomers, the exposure degree of the amino group can be regulated, which is conducive to attracting organic gases into the pores. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with specific examples. The examples may enable professionals in the field to more fully understand the present invention, but do not limit the present invention in any way.

[0023] Example 1: Preparation of covalently polymerized network materials

[0024] (1) Add 5 g of tetrakis(4-formylphenyl)methane to 50 mL of chloroform and disperse by ultrasonic for 10 minutes.

[0025] (2) Dissolve 10 g of polyetheramine in the solution obtained in step (1), disperse by ultrasonication for 30 minutes, and then add 5 mL of 95% acetic acid aqueous solution and disperse by ultrasonication for 5 minutes.

[0026] (3) The above solution was transferred to a polytetrafluoroethylene reactor and heated at 120° C. in a closed environment for 3 days. The obtained crude product was washed with tetrachlorofuran and then vacuum dried at 80° C. for 8 hours to obtain 1 g of the product.

[0027] Example 2

[0028] (1) Add 5 g of tetrakis(4-formylphenyl)methane to 50 mL of 1,4-dioxane and disperse by ultrasonic for 10 minutes.

[0029] (2) Dissolve 10 g of polyetheramine in the solution obtained in step (1), disperse by ultrasonication for 30 minutes, and then add 5 mL of 95% acetic acid aqueous solution and disperse by ultrasonication for 5 minutes.

[0030] (3) The above solution was transferred to a polytetrafluoroethylene reactor and heated at 120° C. in a closed environment for 3 days. The obtained crude product was washed with tetrachlorofuran and then vacuum dried at 80° C. for 8 hours to obtain 1 g of the product.

[0031] Example 3

[0032] (1) Add 5 g of tetrakis(4-formylphenyl)methane to 50 mL of tetrahydrofuran and disperse by ultrasonic for 10 minutes.

[0033] (2) Dissolve 10 g of polyetheramine in the solution obtained in step (1), disperse by ultrasonic for 30 minutes, and then add 5 mL of scandium trifluoromethanesulfonate solution, disperse by ultrasonic for 5 minutes.

[0034] (3) The above solution was transferred to a polytetrafluoroethylene reactor and heated at 120° C. in a closed environment for 3 days. The obtained crude product was washed with tetrachlorofuran and then vacuum dried at 80° C. for 8 hours to obtain 1 g of the product.

[0035] Example 4

[0036] (1) Add 5 g of tetrakis(4-formylphenyl)methane to 50 mL of tetrahydrofuran and disperse by ultrasonic for 10 minutes.

[0037] (2) 10 g of polyetheramine was dissolved in the solution obtained in step (1), and ultrasonic dispersion was performed for 30 minutes. 5 mL of trifluoromethanesulfonic acid solution was added, and ultrasonic dispersion was performed for 5 minutes.

[0038] (3) The above solution was transferred to a polytetrafluoroethylene reactor and heated at 120° C. in a closed environment for 3 days. The obtained crude product was washed with tetrachlorofuran and then vacuum dried at 80° C. for 8 hours to obtain 1 g of the product.

[0039] Example 5

[0040] (1) Add 5 g of tetrakis(4-formylphenyl)methane to 50 mL of tetrahydrofuran and disperse by ultrasonic for 10 minutes.

[0041] (2) Dissolve 10 g of polyetheramine in the solution obtained in step (1), disperse by ultrasonic for 30 minutes, and then add 5 mL of p-toluenesulfonic acid solution and disperse by ultrasonic for 5 minutes.

[0042] (3) The above solution was transferred to a polytetrafluoroethylene reactor and heated at 120° C. in a closed environment for 3 days. The obtained crude product was washed with tetrachlorofuran and then vacuum dried at 80° C. for 8 hours to obtain 1 g of the product.

[0043] The preparation method of the covalent polymer network material of the present invention is specifically demonstrated through 5 examples. The experimental data in each example are shown in Table 1.

[0044] Table 1 Preparation test data of covalent polymer network materials of Examples 1-5

[0045] Example No. 1 2 3 4 5 <![CDATA[Concentration of tetrakis(4-formylphenyl)methane (mg mL -1 )]]> 100 100 100 100 100 Weight average molecular weight of polyetheramine 200 1000 1500 2000 1500 Molar ratio of amine group to aldehyde group 1:1 1:1 1:1 1:1 1.5:1

[0046] Technical effect verification

[0047] VOCs adsorption experiments were conducted on the covalent polymer network materials prepared in Examples 1-5:

[0048] The materials prepared in Examples 1, 2, 3, 4, and 5 were used to adsorb typical substances such as styrene and octane in VOCs. 100 mg of covalent polymer network material was weighed respectively and loaded into three adsorption columns A, B, and C. 10 mg / L of organic gas was connected to the lower ports of A, B, and C adsorption columns respectively, and column penetration adsorption was performed at the same gas flow rate. 300 L of nitrogen was passed through the A, B, and C adsorption columns and collected in Tedlar bags respectively. The organic gas concentration was detected by gas chromatography. The material adsorption efficiency was calculated by calculating the gas volume and concentration in the plastic bag, as shown in Table 2.

[0049] Material adsorption rate C r=(1-V2C2 / V1C1)×100%, where V1 is the intake volume (L), C1 is the intake concentration (mg / L), V2 is the volume of gas after passing through the adsorption column (L), and C2 is the concentration of gas after passing through the adsorption column (mg / L).

[0050] Table 2 Test results of covalent polymer network materials adsorbing VOCs in Examples 1-5

[0051]

[0052] The material of the present invention can adjust the pore size range of the pores by adjusting the molecular weight of the polyetheramine, which is conducive to the adsorption of organic matter of different sizes. In addition, by adjusting the stoichiometric ratio of the monomers, the exposure degree of the amino group can be regulated, which is conducive to attracting organic gases into the pores. Among them, the total adsorption efficiency of styrene can reach up to 92.79%, and the total adsorption efficiency of octane can reach up to 91.12%.

[0053] The present invention has been described in detail herein and specific embodiments of the present invention have been illustrated by way of example in the Examples section, but various modifications and alternative forms may also be made to the present invention. However, it should be understood that it is not intended that the present invention be limited to the disclosed specific forms herein. On the contrary, the present invention encompasses all modifications, equivalents and alternatives that fall within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A covalent polymer network material for adsorbing VOCs, characterized in that: The covalent polymerized network material is prepared by polycondensation of tetrakis(4-formylphenyl)methane and polyetheramine in an organic solvent.

2. The covalently polymerized network material according to claim 1, characterized in that: The weight average molecular weight of the polyetheramine is 200-2000.

3. The method for preparing a covalently polymerized network material according to claim 1, characterized in that: The following steps are involved: (1) adding tetrakis(4-formylphenyl)methane to an organic solvent and performing ultrasonic dispersion to obtain a solution A; (2) adding polyetheramine to solution A, dispersing by ultrasonication, and then adding a catalyst to obtain solution B; (3) Transferring solution B to a polytetrafluoroethylene reactor, reacting in a closed environment at 100-180° C. for 2-8 days, washing the resulting crude product with an organic solvent, and vacuum drying to obtain the covalently polymerized network material.

4. The preparation method according to claim 3, characterized in that: In step (1), the organic solvent is selected from 1,4-dioxane, tetrahydrofuran or chloroform.

5. The preparation method according to claim 3, characterized in that: In step (2), the molar ratio of the amino group contained in the polyetheramine to the aldehyde group contained in tetrakis(4-formylphenyl)methane is 1 to 1.5:

1.

6. The preparation method according to claim 3, characterized in that: In step (2), the catalyst is selected from one or more of acetic acid, scandium trifluoromethanesulfonate, trifluoromethanesulfonic acid, and p-toluenesulfonic acid.

7. The preparation method according to claim 3, characterized in that: In step (3), the organic solvent used for cleaning is selected from one or more of tetrahydrofuran, acetone, ethanol, 1,4-dioxane, and chloroform.

8. Use of the covalent polymerized network material as claimed in claim 1 in adsorbing VOCs.

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