Formaldehyde scavenger, preparation method and application thereof

Abstract

The present invention discloses a formaldehyde scavenger and its preparation method and application. In parts by mass, the raw material composition of the formaldehyde scavenger includes: 3 to 5 parts of polymerized amine-modified molecular sieves, 0.05 to 0.2 parts of pH buffer, 2 to 5 parts of sealing agent, and 70 to 90 parts of water; the preparation method of the polymerized amine-modified molecular sieve includes: using a wet impregnation method, under stirring conditions, adding an aminosilane-grafted molecular sieve to a mixed solution of polyethyleneimine and a surfactant, continuously stirring for a period of time, and drying to obtain a polymerized amine-modified molecular sieve; the aminosilane-grafted molecular sieve is an MCM-41 or SBA-15 tubular molecular sieve in which 3-aminopropyltriethoxysilane is grafted in situ by a hydrothermal synthesis method. The present invention discloses a highly efficient formaldehyde scavenger without secondary pollution, which achieves the complete elimination of formaldehyde by combining physical adsorption and chemical reaction, and has the advantages of long-term stability, ultra-high formaldehyde removal rate, and no secondary pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of formaldehyde purification, and in particular to a formaldehyde scavenger, a preparation method thereof and an application thereof. Background Art

[0002] Indoor air pollution generally refers to all pollution in homes, offices, public buildings, etc. that can cause human discomfort and other acute and chronic potential damage.

[0003] The artificial boards used in decoration are an important component of the existing decorative materials. They are made of adhesives based on formaldehyde, such as urea-formaldehyde resin glue, phenol-formaldehyde resin glue, and melamine glue. Their decomposition will cause the gradual release of formaldehyde, with a half-life of 3-15 years, making it the main source of indoor formaldehyde.

[0004] According to relevant data, when the formaldehyde content in indoor air is 0.1mg / m 3 , people will feel odor and discomfort; 0.5mg / m 3 May cause throat discomfort or pain; higher doses may cause nausea, vomiting, coughing, chest tightness, asthma, and even emphysema; 30 mg / m 3 It can cause immediate death. Long-term exposure to low doses of formaldehyde can cause chronic respiratory diseases, pregnancy complications in women, reduced physical fitness in newborns, chromosomal abnormalities, and even nasopharyngeal cancer. High concentrations of formaldehyde are toxic to the nervous system, immune system, and liver, and can also cause birth defects and cancer. Therefore, eliminating free formaldehyde indoors is crucial.

[0005] Formaldehyde scavengers use complex reactions, oxidation reactions, addition reactions, etc. to destroy and decompose formaldehyde, generating non-toxic reaction products to eliminate indoor air pollution.

[0006] The patent specification with publication number CN109499041A discloses a highly efficient and environmentally friendly formaldehyde scavenger, which includes 100 parts by weight of Y-type molecular sieve treated with high-temperature steam, 5-15 parts by weight of nano-titanium dioxide, 1-20 parts by weight of sesbania gum, 1000-3000 parts by weight of acetic acid-sodium acetate buffer solution, 4-20 parts by weight of nano-iron oxide, 5-30 parts by weight of nano-molybdenum disulfide, 100-500 parts by weight of an organic solvent and 50-200 parts by weight of a foaming agent.

[0007] The patent specification with publication number CN109432979A discloses a scavenger with high-efficiency formaldehyde purification function, which includes the following ingredients in weight percentage: 4-6% natural plant extract, 1-3% 4a molecular sieve, 1-3% diatomaceous earth, 10-14% nano-TiO2 sol, 1-3% sodium dodecylbenzenesulfonate, 1-3% biological enzyme, 2-4% lemon wax, 2-4% tea, and the rest is deionized water.

[0008] However, there are still the following problems with formaldehyde removers on the market:

[0009] 1) Secondary pollution release. Formaldehyde removers rely on chemical reactions to remove pollutants, which may produce new pollutants, thus causing secondary pollution. In addition, such high-concentration removers may also affect indoor air or human body when used.

[0010] 2) Short duration of action. In actual use, the volatilization time of free formaldehyde generally lasts for 10 to 15 years. The effective ingredients added to the scavenger are limited. Once the effectiveness is lost, the free formaldehyde in the wood-based panel will still be released in large quantities, causing indoor air pollution. Summary of the Invention

[0011] The present invention provides a highly efficient formaldehyde scavenger without secondary pollution, which achieves complete elimination of formaldehyde by combining physical adsorption and chemical reaction, and has the advantages of long-term stability, ultra-high formaldehyde removal rate, and no secondary pollution.

[0012] A formaldehyde scavenger, the raw materials of which are calculated by weight:

[0013]

[0014] The preparation method of the polymerized amine-modified molecular sieve comprises: using a wet impregnation method, adding an aminosilane-grafted molecular sieve to a mixture of polyethyleneimine (preferably polyethyleneimine with a branched structure) and a surfactant under stirring, continuously stirring for a period of time, and then drying to obtain the polymerized amine-modified molecular sieve;

[0015] The aminosilane-grafted molecular sieve is an MCM-41 or SBA-15 tubular molecular sieve that is in-situ grafted with 3-aminopropyltriethoxysilane using a hydrothermal synthesis method.

[0016] The invention firstly adopts a hydrothermal synthesis method to in-situ introduce 3-aminopropyltriethoxysilane into the pores of MCM-41 or SBA-15 tubular molecular sieves, and then adopts a wet impregnation method to load polyethyleneimine into the pores of the molecular sieve through hydrogen bonding to prepare a polymeric amine modified molecular sieve.

[0017] The formaldehyde scavenger of the present invention utilizes a combination of physical adsorption and chemical reaction to highly disperse a stable amino polymer within the pores of an aminosilane-grafted molecular sieve. Free formaldehyde in the air is rapidly aggregated and adsorbed. Utilizing the spatial confinement effect of the molecular sieve, formaldehyde undergoes a nucleophilic addition reaction with the amino groups in the pores to form a stable and harmless compound. As the reaction proceeds, more amino active sites are gradually exposed, achieving the goal of long-term and continuous formaldehyde elimination. While ensuring the quality of wood-based panels, this formaldehyde scavenger offers advantages such as long-term stability, ultra-high formaldehyde removal rates, and zero secondary pollution.

[0018] The present invention limits formaldehyde release by allowing a large number of amino reactive groups to undergo a nucleophilic addition reaction with formaldehyde. While amino compounds are generally volatile, causing secondary pollution, the present invention utilizes an amino polymer, polyethyleneimine, which exhibits excellent chemical stability and is nonvolatile.

[0019] The formaldehyde scavenger preferably has an amount of polyethyleneimine of 35% to 45% based on the mass of the aminosilane-grafted molecular sieve.

[0020] The formaldehyde scavenger preferably has an amount of the surfactant of 1% to 10% based on the mass of the aminosilane-grafted molecular sieve.

[0021] The surfactant can disperse the polyethyleneimine, allowing the amino groups to fully expand in the molecular sieve pores, thereby gradually reacting with the continuously generated formaldehyde. The surfactant can be a mixture of one or more of dimethyl sulfoxide, sodium lauryl sulfate, Triton X-100, sodium di-sec-octyl maleate sulfonate, sodium di-isooctyl maleate sulfonate, and Tween 20.

[0022] Tubular molecular sieves MCM-41 and SBA-15 are fully connected open tubular pore structures. This structure can significantly reduce the internal mass transfer resistance during the dynamic adsorption process of gas, thereby improving the adsorption efficiency and effectively adsorbing formaldehyde in the molecular sieve pores. The present invention first uses an in-situ hydrothermal synthesis method to introduce 3-aminopropyltriethoxysilane into the molecular sieve pores, and then uses a wet impregnation method to load polyethyleneimine into the molecular sieve pores. At this time, the amino groups of polyethyleneimine and the amino groups in the molecular sieve pores are connected by hydrogen bonds, thereby preparing a polymerized amine-modified molecular sieve. The amino polymer polyethyleneimine is introduced into the aminosilane-grafted molecular sieve pores, which not only reduces the volatility of the amino polymer, but also, due to the spatial confinement effect, formaldehyde can gradually undergo a nucleophilic addition reaction with the amino polymer in the molecular sieve pores. As the reaction proceeds, more active sites are continuously exposed and the deactivation is not rapid, thereby achieving the purpose of long-term and lasting elimination of formaldehyde.

[0023] In a preferred example, the preparation method of the aminosilane-grafted molecular sieve includes: adding tetraethyl orthosilicate and ammonia water to a hexadecyltrimethylammonium bromide solution under stirring, adding 3-aminopropyltriethoxysilane after continuous stirring for a period of time, continuing stirring at 35-45°C, and then subjecting the resulting emulsion to hydrothermal treatment at 100-105°C. The resulting precipitate is thoroughly washed with ethanol and deionized water to remove hexadecyltrimethylammonium bromide and inorganic ions, and then dried to obtain a 3-aminopropyltriethoxysilane-grafted MCM-41 tubular molecular sieve.

[0024] In another preferred example, the preparation method of the aminosilane-grafted molecular sieve includes: under stirring conditions, first adding ethyl orthosilicate and ammonia water to the P123 solution, continuing stirring for a period of time and then adding 3-aminopropyltriethoxysilane, continuing stirring at 35-45°C, and then subjecting the obtained emulsion to hydrothermal treatment at 100-105°C. The obtained precipitate is fully washed with ethanol and deionized water to remove P123 and inorganic ions, and then dried to obtain 3-aminopropyltriethoxysilane-grafted SBA-15 tubular molecular sieve.

[0025] In the above two preferred methods for preparing aminosilane-grafted molecular sieves, the mass ratio of the 3-aminopropyltriethoxysilane to the tetraethyl orthosilicate is preferably 0.1 to 0.2:1.

[0026] The formaldehyde scavenger and the pH buffer may be sodium tripolyphosphate.

[0027] The sealant itself has a certain degree of film-forming properties, forming a stable submicron-level film on the surface of the furniture board. It adheres well to the surface of the furniture board, restricting the rapid diffusion of formaldehyde released from the furniture board and providing long-term adsorption and decomposition on the board surface. The sealant can be a mixture of one or more of carboxymethyl chitosan, chitosan sulfate, chitosan oligosaccharides (preferably with a degree of polymerization of 2-20), and hyaluronic acid-like chitosan.

[0028] The present invention also provides a preparation method of the formaldehyde scavenger, and the formaldehyde scavenger is obtained by uniformly mixing the raw materials.

[0029] The present invention also provides application of the formaldehyde scavenger in removing formaldehyde released from furniture panels.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention uses 3-aminopropyltriethoxysilane and polyethyleneimine as effective ingredients for removing free formaldehyde in artificial boards. The aminosilane is in situ grafted into the molecular sieve pores, which can form a strong interaction with the polyethyleneimine, thereby improving the loading capacity and stability of the polyamine. At the same time, the surfactant can effectively disperse the amino polymer, allowing the amino groups to fully expand. On the one hand, the polyamine-modified molecular sieve covers the outermost layer of the board, and the gaseous free formaldehyde around the board is quickly accumulated and adsorbed in the molecular sieve pores. By utilizing the spatial confinement effect of the molecular sieve, the amino groups in the pores react with the adsorbed formaldehyde to produce a stable, non-toxic and harmless high molecular polymer. As the reaction proceeds, more active sites are exposed, achieving the purpose of long-term and stable elimination of formaldehyde. On the other hand, under the action of the sealing agent, the formaldehyde scavenger forms a dense film-like structure on the first layer of the artificial board surface, which can effectively inhibit the free formaldehyde from volatilizing outward through the artificial board surface and ensure the effective adsorption and decomposition of formaldehyde on the board surface. All components in the present invention are safe and non-toxic raw materials, and the reaction products are stable and non-toxic, will not cause secondary pollution during use, and will not cause harm to users. While ensuring the quality of wood-based panels, the present invention has the characteristics of high elimination rate, strong timeliness, and no secondary pollution, and has great social benefits. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

[0033] The formaldehyde removal effect is determined according to the method in the Chinese standard GB / T 35239-2017 "Test method for the removal ability of formaldehyde scavengers for wood-based panels and their products".

[0034] Unless otherwise specified, “parts” in the following examples refer to “parts by mass”.

[0035] Example 1

[0036] The preparation method of the formaldehyde scavenger involved in this embodiment comprises the following steps:

[0037] (1) Preparation of aminosilane-grafted MCM-41 molecular sieve: Using a hydrothermal synthesis method, 2.4 g of the template agent hexadecyltrimethylammonium bromide (CTAB) was dissolved in 120 mL of deionized water at room temperature. Then, 10 g of tetraethyl orthosilicate (TEOS) and 8 mL of ammonia water (concentration of 25 wt%-28 wt%) were added dropwise under continuous stirring. After continuous stirring for 1 h, 1.607 g of 3-aminopropyltriethoxysilane was added and stirring was continued at 40°C for 10 h. The resulting emulsion was then transferred to a Teflon-lined autoclave and hydrothermally treated at 100°C for 24 h. The precipitate was removed and washed with 400 mL of ethanol under reflux for 4 h, repeated three times, and then washed again with deionized water. Finally, the obtained sample was filtered and vacuum-dried at 60°C for 12 h to obtain aminosilane-grafted MCM-41 molecular sieve.

[0038] (2) Preparation of polymeric amine modified molecular sieve: 6 parts of branched polyethyleneimine and 0.5 parts of surfactant sodium dioctyl maleate sulfonate were dissolved in a certain amount of deionized water by wet impregnation method under stirring. A certain amount of aminosilane grafted MCM-41 molecular sieve was added according to the branched polyethyleneimine loading amount of 40 wt% (based on the mass of aminosilane grafted MCM-41 molecular sieve), and stirring was continued for 2.5 h. The mixture was dried in a vacuum drying oven at 100°C for 12 h and ground to obtain a polymeric amine modified molecular sieve.

[0039] (3) Preparation of formaldehyde scavenger: 0.1 parts of pH regulator sodium tripolyphosphate, 5 parts of polymerized amine-modified molecular sieve, 3 parts of blocking agent carboxymethyl chitosan and 85 parts of water were stirred at room temperature at a speed of 700 rpm for 2 hours and the formaldehyde scavenger was prepared after being fully mixed.

[0040] Performance test: The formaldehyde scavenger obtained in this embodiment was tested. 27.8g of formaldehyde scavenger sample was evenly sprayed on 20 15cm×15cm test panels after equilibrium treatment. After standing for a period of time, the formaldehyde release of the comparison sample (test panel not sprayed with formaldehyde scavenger sample) and the sprayed sample was tested, and the clearance rate was calculated based on the concentration change. Test results after 24h: the formaldehyde concentration value of the comparison group was 3.35mg / L, the formaldehyde concentration value of the sample group was 0.22mg / L, and the calculated formaldehyde clearance rate was 93.4%. Test results after 1 month: the formaldehyde concentration value of the comparison group was 3.28mg / L, the formaldehyde concentration value of the sample group was 0.32mg / L, and the calculated formaldehyde clearance rate was 90.2%. Test results after 3 months: the formaldehyde concentration value of the comparison group was 3.03mg / L, the formaldehyde concentration value of the sample group was 0.36mg / L, and the calculated formaldehyde clearance rate was 88.1%.

[0041] Example 2

[0042] The preparation method of the formaldehyde scavenger involved in this embodiment comprises the following steps:

[0043] (1) Preparation of aminosilane-grafted SBA-15 molecular sieve: Using a hydrothermal synthesis method, 8.0 g of the template polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123) was dissolved in 195.16 g of deionized water and stirred at room temperature for 2 h. 15.35 g of tetraethyl orthosilicate (TEOS) and 10 mL of ammonia water (concentration of 25 wt%-28 wt%) were added dropwise. After continuous stirring for 45 min, 1.607 g of 3-aminopropyltriethoxysilane was added and stirred at 40°C for another 12 h. The resulting emulsion was hydrothermally treated at 100°C for 24 h. The precipitate was removed and washed with 400 mL of ethanol under reflux for 4 h, repeated three times, and then washed once more with deionized water. Finally, the obtained sample was filtered and vacuum dried at 60°C for 12 h to obtain aminosilane-grafted SBA-15 molecular sieve for use.

[0044] (2) Preparation of polymeric amine modified molecular sieve: Using the wet impregnation method, 6 parts of branched polyethyleneimine and 0.5 parts of surfactant sodium dioctyl sulfonate maleate were dissolved in a certain amount of deionized water under stirring. According to the branched polyethyleneimine loading amount of 40wt% (based on the mass of aminosilane grafted SBA-15 molecular sieve), a certain mass of aminosilane grafted SBA-15 molecular sieve was added, and stirring was continued for 2.5h. The mixture was dried in a vacuum drying oven at 100°C for 12h and ground to obtain the polymeric amine modified molecular sieve.

[0045] (3) Preparation of formaldehyde scavenger: 0.1 parts of pH regulator sodium tripolyphosphate, 5 parts of polymerized amine-modified molecular sieve, 3 parts of blocking agent chitosan oligosaccharide and 90 parts of water were stirred at room temperature at a speed of 700 rpm for 2 h. After being fully mixed, the formaldehyde scavenger was prepared.

[0046] Performance test: The formaldehyde scavenger obtained in this embodiment was tested. 27.8g of formaldehyde scavenger sample was evenly sprayed on 20 15cm×15cm test plates after equilibrium treatment. After standing for a period of time, the formaldehyde release of the comparison sample (test plate without formaldehyde scavenger sample) and the sprayed sample was tested, and the clearance rate was calculated based on the concentration change. Test results after 24h: the formaldehyde concentration value of the comparison group was 3.51mg / L, the formaldehyde concentration value of the sample group was 0.28mg / L, and the calculated formaldehyde clearance rate was 92%. Test results after 1 month: the formaldehyde concentration value of the comparison group was 3.42mg / L, the formaldehyde concentration value of the sample group was 0.36mg / L, and the calculated formaldehyde clearance rate was 89.5%. Test results after 3 months: the formaldehyde concentration value of the comparison group was 3.28mg / L, the formaldehyde concentration value of the sample group was 0.43mg / L, and the calculated formaldehyde clearance rate was 86.9%.

[0047] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A formaldehyde scavenger, characterized in that: In parts by mass, the raw material composition includes: The preparation method of the polymerized amine modified molecular sieve comprises: using a wet impregnation method, adding an aminosilane grafted molecular sieve to a mixture of polyethyleneimine and a surfactant under stirring, stirring for a period of time, and drying to obtain the polymerized amine modified molecular sieve; The aminosilane-grafted molecular sieve is an MCM-41 or SBA-15 tubular molecular sieve that is in-situ grafted with 3-aminopropyltriethoxysilane using a hydrothermal synthesis method.

2. The formaldehyde scavenger according to claim 1, characterized in that Based on the mass of the aminosilane-grafted molecular sieve, the amount of the polyethyleneimine is 35% to 45%.

3. The formaldehyde scavenger according to claim 1, characterized in that Based on the mass of the aminosilane-grafted molecular sieve, the dosage of the surfactant is 1% to 10%.

4. The formaldehyde scavenger according to claim 1 or 3, characterized in that The surfactant is a mixture of one or more of dimethyl sulfoxide, sodium lauryl sulfate, Triton X-100, sodium di-sec-octyl maleate sulfonate, sodium di-isooctyl maleate sulfonate, and Tween 20.

5. The formaldehyde scavenger according to claim 1, characterized in that The preparation method of the aminosilane-grafted molecular sieve comprises: adding tetraethyl orthosilicate and ammonia water to a hexadecyltrimethylammonium bromide solution under stirring, continuously stirring for a period of time, then adding 3-aminopropyltriethoxysilane, continuing stirring at 35-45° C., then subjecting the obtained emulsion to a hydrothermal treatment at 100-105° C., washing the obtained precipitate with ethanol and deionized water to remove hexadecyltrimethylammonium bromide and inorganic ions, and then drying to obtain a 3-aminopropyltriethoxysilane-grafted MCM-41 tubular molecular sieve.

6. The formaldehyde scavenger according to claim 1, characterized in that The preparation method of the aminosilane-grafted molecular sieve comprises: adding tetraethyl orthosilicate and ammonia water to a P123 solution under stirring conditions, continuously stirring for a period of time, then adding 3-aminopropyltriethoxysilane, continuing stirring at 35-45° C., and then subjecting the obtained emulsion to a hydrothermal treatment at 100-105° C. The obtained precipitate is fully washed with ethanol and deionized water to remove P123 and inorganic ions, and then dried to obtain a 3-aminopropyltriethoxysilane-grafted SBA-15 tubular molecular sieve.

7. The formaldehyde scavenger according to claim 5 or 6, characterized in that The mass ratio of the 3-aminopropyltriethoxysilane to the tetraethyl orthosilicate is 0.1-0.2:

1.

8. The formaldehyde scavenger according to claim 1, characterized in that The pH buffer is sodium tripolyphosphate; The sealing agent is a mixture of one or more of carboxymethyl chitosan, chitosan sulfate, chitosan oligosaccharide, and hyaluronic acid-like chitosan.

9. The method for preparing the formaldehyde scavenger according to any one of claims 1 to 8, characterized in that: The formaldehyde scavenger is obtained by uniformly mixing the raw materials.

10. Use of the formaldehyde scavenger according to any one of claims 1 to 8 in removing formaldehyde released from furniture panels.

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