A polymer membrane for filtering atmospheric particulate matter, a preparation method and applications thereof

Abstract

The application discloses a preparation method of a polymer membrane for filtering atmospheric particulate matters, and comprises the following steps: S1, reacting a melamine solution with a formaldehyde solution in an alkaline environment to obtain a reacted solution; S2, heating and drying the reacted solution under vacuum to obtain a dried product; S3, adding the dried product, a compound A and an isocyanate monomer into a solvent, and performing a reaction under a protective atmosphere to obtain a reactant, wherein the compound A is selected from one or more of polyether, amine compounds, mercaptan compounds and alcohol compounds; and S4, heating and drying the reactant obtained in S3 under vacuum, so that the polymer membrane is obtained. The preparation method is simple and easy to implement, and the prepared polymer membrane has good separation efficiency and can effectively remove PM2.5 and PM10 particulate pollutants in the atmosphere.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air pollution treatment, in particular to a polymer membrane for filtering atmospheric particulate matter, a preparation method and application thereof. BACKGROUND

[0002] At present, activated carbon, fiber, zeolite, resin and other materials can be prepared into various micro-nano filters, which have been widely developed and applied in the separation and purification of atmospheric particulate matter. However, these filtering materials have their own shortcomings or limitations, for example, it is difficult for inorganic filters (carbon, clay, etc.) or organic filter pore filters (fiber materials, resins, etc.) to capture suspended particulate matter with different particle sizes, especially the separation efficiency for PM2.5 and PM10 atmospheric solid particles is not high. SUMMARY

[0003] In order to solve the defects in the prior art, the present application provides a polymer membrane for filtering atmospheric particulate matter, a preparation method and application thereof. The preparation method is simple and easy to operate, and the prepared polymer membrane has good separation efficiency and can effectively remove PM2.5 and PM10 particulate pollutants in the atmosphere.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0005] In a first aspect, the present application provides a preparation method of a polymer membrane for filtering atmospheric particulate matter, comprising the following steps:

[0006] S1. In an alkaline environment, a melamine solution is reacted with a formaldehyde solution to obtain a reacted solution;

[0007] S2. The reacted solution is heated and dried under vacuum to obtain a dried product;

[0008] S3. The dried product, compound A and isocyanate monomer are added to a solvent, and the reaction is carried out under a protective atmosphere to obtain a reaction product, wherein the compound A is selected from one or more of polyether, amine compound, thiol compound and alcohol compound;

[0009] S4. The reaction product of S3 is heated and dried under vacuum to obtain the polymer membrane.

[0010] Preferably, the molar ratio of melamine to formaldehyde in S1 is 1:3.

[0011] In S1, the solution for adjusting the alkaline environment can be a conventional alkaline solution such as sodium hydroxide or potassium hydroxide solution in the art.

[0012] Preferably, in the S1, the pH value of the alkaline environment is 8.6-9.0. The reaction environment of the S1 of the present application is a weak alkaline environment, which is conducive to the homogeneous polymerization reaction and prevents local reaction from being uneven.

[0013] Preferably, in the S1, the reaction temperature is 55-60℃, and the reaction time is 0.5-0.6h.

[0014] Preferably, in the S2 and S4, the temperature for heating and drying is 65-70℃.

[0015] Preferably, in the S3, the solvent is ethanol and / or butanone.

[0016] More preferably, in the S3, the solvent is ethanol and butanone, and the volume ratio of the ethanol to the butanone is 1:1.

[0017] Preferably, in the S3, the structural formula of the compound A includes any one or more of the following formula (1)-(7):

[0018]

[0019] In some embodiments of the present application, the compound A is ethylene glycol; in other embodiments of the present application, the compound A is triethylene glycol; and in other embodiments of the present application, the compound A is ethanolamine.

[0020] Preferably, in the S3, the molecular weight of the polyether is 100.0-400.0g / mol.

[0021] Preferably, in the S3, the isocyanate monomer is selected from any one of toluene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate.

[0022] Preferably, in the S3, the mass ratio of the melamine, the formaldehyde, the isocyanate monomer, and the compound A is (1.6-2.4):(1.1-1.7):(0.5-0.8):(0.15-0.36).

[0023] Preferably, in the S3, the temperature for the mixed reaction is 70-80℃, and the reaction time is 2.0-3.0h. More preferably, in the S3, the temperature for the mixed reaction is 75-78℃.

[0024] In a second aspect, the present application provides a polymer film obtained by the above preparation method.

[0025] Preferably, the polymer film includes the following structure:

[0026] a structure with micro-nanopores;

[0027] Melamine formaldehyde is used as a skeleton, and polyurethane polymer chains are grafted on the surface;

[0028] The pore size of the micro-nanopore is about 85nm-330nm.

[0029] The structure is a core-shell structure sponge.

[0030] In a third aspect, the application provides application of the polymer membrane in filtering atmospheric particulate matters.

[0031] Preferably, the atmospheric particulate matters are PM2.5 and PM10.

[0032] The application has the following advantages:

[0033] The preparation method of the polymer membrane for filtering atmospheric particulate matters is as follows: melamine and formaldehyde are first reacted in an alkaline environment, the dry product is then reacted with the compound A to obtain a precursor of the polymer membrane, and the precursor has a porous sponge structure; and then the precursor is reacted with an isocyanate monomer, which has a strong adsorption effect on organic aerosol components, so that separation is achieved. The raw materials are easy to obtain, the cost is low, the preparation process is simple and efficient, the repeatability is high, and the application is easy to popularize.

[0034] The polymer membrane prepared by the application has excellent separation effect and good mechanical properties, and can efficiently and quickly remove particulate pollutants in the atmosphere, with high removal efficiency of PM2.5 and PM10. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solutions of the application, the application will be further described in detail below with reference to the specific embodiments.

[0036] Example 1

[0037] S1, 4.5g of melamine solution (mass fraction 35%), 3.0g of formaldehyde solution (mass fraction 37%) were sequentially added to a flask, 0.05mol / L sodium hydroxide aqueous solution was added dropwise until the solution pH was 9.0, heated to 55℃, and the reaction time was 0.5-0.6h under the condition of magnetic stirring, to obtain a reacted solution;

[0038] S2, the reacted solution was dried at 65℃ under vacuum overnight to obtain a dry product;

[0039] S3, the dry product was crushed and added to 20mL of a mixed solvent of ethanol and butanone in a volume ratio of 1:1, 0.5g of toluene diisocyanate and 0.36g of ethylene glycol were added to the solvent, and the reaction was carried out under nitrogen protection at 75℃ for 2.0-3.0h to obtain a reaction product.

[0040] S4, dry the reactant under vacuum at 65℃ overnight, to obtain the polymer film.

[0041] Example 2

[0042] S1, add 4.5g of melamine solution (mass fraction 35%) and 3.0g of formaldehyde solution (mass fraction 37%) into a flask in sequence, drop 0.05mol / L sodium hydroxide aqueous solution into the solution until the pH is 9.0, heat to 55℃, and react for 0.5-0.6h under magnetic stirring, to obtain the reacted solution;

[0043] S2, dry the reacted solution under vacuum at 70℃ overnight, to obtain the dry product;

[0044] S3, crush the dry product, add into 25mL of mixed solvent of ethanol and butanone with a volume ratio of 1:1, then add 0.6g of diphenylmethane diisocyanate and 0.30g of ethylene glycol into the solution, heat to 75℃ under nitrogen protection, and react for 2.0-3.0h, to obtain the reactant;

[0045] S4, dry the reactant under vacuum at 70℃ overnight, to obtain the polymer film with core-shell structure and sponge shape.

[0046] Example 3

[0047] S1, add 6.8g of melamine solution (mass fraction 35%) and 4.5g of formaldehyde solution (mass fraction 37%) into a flask in sequence, drop 0.05mol / L sodium hydroxide aqueous solution into the solution until the pH is 9.0, heat to 60℃, and react for 0.5-0.6h under magnetic stirring, to obtain the reacted solution;

[0048] S2, dry the reacted solution under vacuum at 70℃ overnight, to obtain the dry product;

[0049] S3, crush the dry product, add into 32mL of mixed solvent of ethanol and butanone with a volume ratio of 1:1, then add 0.5g of naphthalene diisocyanate and 0.25g of ethylene glycol into the solution, heat to 78℃ under nitrogen protection, and react for 2.0-3.0h, to obtain the reactant;

[0050] S4, dry the reactant under vacuum at 70℃ overnight, to obtain the polymer film with core-shell structure and sponge shape.

[0051] Example 4

[0052] The same as Example 1, except that in S3 step, ethylene glycol is replaced by triethylene glycol with a mass of 0.15g.

[0053] Example 5

[0054] The same as example 2, the only difference is that in S3 step, ethylene glycol is replaced by ethanolamine, the mass is 0.28g.

[0055] Example 6

[0056] The same as example 1, the only difference is that in S1 step, 0.05mol / L sodium hydroxide aqueous solution is added dropwise to the solution pH is 8.6.

[0057] Example 7

[0058] The same as example 1, the only difference is that in S1 step, 0.05mol / L sodium hydroxide aqueous solution is added dropwise to the solution pH is 8.8.

[0059] Example 8

[0060] The same as example 3, the only difference is that in S3 step, the isocyanate is added to toluene diisocyanate 0.5g.

[0061] Example 9

[0062] The same as example 3, the only difference is that in S3 step, the isocyanate is added to diphenylmethane diisocyanate 0.5g.

[0063] Example 10

[0064] The same as example 3, the only difference is that in S3 step, the isocyanate is added to toluene diisocyanate 0.8g.

[0065] The polymer film obtained from examples 1-7 is tested for PM2.5 and PM10 removal rate performance, three groups of parallel tests are carried out respectively, and the results are shown in table 1:

[0066] Table 1 PM2.5 and PM10 removal rate performance of polymer film

[0067]

[0068]

[0069] The detection experiment adopts national standard: environmental air particulate matter (PM10 and PM2.5) sampler technical requirements and detection method.

[0070] Through comparison experiment, increasing the content of toluene diisocyanate can improve the removal rate of PM2.5 and PM10, and the isocyanate performance ranking is: toluene diisocyanate > diphenylmethane diisocyanate and naphthalene diisocyanate.

[0071] The above merely describes the preferred embodiments of the present application, and it should be pointed out that the above preferred embodiments should not be regarded as a limitation to the present application, and the protection scope of the present application should be defined by the scope of the claims. For those skilled in the art, several improvements and refinements can be made without departing from the spirit and scope of the present application, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A method for producing a polymer film for filtering atmospheric particulate matter, characterized by, The method comprises the following steps: S1. reacting a melamine solution with a formaldehyde solution in an alkaline environment to obtain a reacted solution; S2. drying the reacted solution under vacuum to obtain a dry product; S3. adding the dry product, compound A and an isocyanate monomer in a solvent and reacting under a protective atmosphere to obtain a reaction product, wherein the compound A is selected from one or more of polyether, amine compound, thiol compound and alcohol compound; S4. drying the reaction product of S3 under vacuum to obtain the polymer film.

2. The production method according to claim 1, characterized by, The molar ratio of melamine to formaldehyde in S1 is 1:

3.

3. The preparation method according to claim 1, characterized in that, The pH value of the alkaline environment in S1 is 8.6-9.

0.

4. The method of claim 1, wherein, The reaction temperature in S1 is 55-60℃, and the reaction time is 0.5-0.6h.

5. The preparation method according to claim 1, characterized in that, The solvent in S3 is ethanol and / or butanone.

6. The method of claim 1, wherein, The isocyanate monomer in S3 is selected from any one of toluene diisocyanate, diphenylmethane diisocyanate and naphthalene diisocyanate.

7. The preparation method according to claim 1, characterized in that, The mass ratio of melamine, formaldehyde, isocyanate monomer and compound A is (1.6-2.4):(1.1-1.7):(0.5-0.8):(0.15-0.36).

8. A polymer film prepared by the method of any one of claims 1-7.

9. Use of the polymer film of claim 8 in filtering atmospheric particulate matter.

10. Use according to claim 9, characterized in that, The atmospheric particulate matter is PM2.5 and PM10.

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