A method for preparing an enzyme-catalyzed bio-based nylon coagent

Abstract

The application discloses a preparation method of an enzyme-catalyzed bio-based nylon auxiliary, and belongs to the technical field of enzyme catalysis synthesis. Furan dicarboxylic acid dialkyl ester and tetramethyl piperidine amine are used as raw materials, and under the catalysis of an enzyme catalyst, the reaction is carried out in an organic solvent at a low reaction temperature. After the reaction is completed, the target product, bio-based nylon auxiliary N,N'-bis (2,2,6,6-tetramethyl-4-piperidyl) 2,5-furan dicarboxamide, is obtained by post-treatment of the reaction mixture. The method disclosed by the application does not involve high-risk and toxic reagents such as metal catalysts and alkalis. The method does not involve high-temperature conditions, the reaction temperature is 30 DEG C to 45 DEG C, the reaction temperature is mild and safe, and the requirement for equipment is low. The content of the obtained product on a gas chromatograph can reach more than 99%, and the yield can reach more than 95%.

Description

A method for preparing an enzyme-catalyzed bio-based nylon adjuvant Technical Field

[0001] This invention relates to a method for preparing an enzyme-catalyzed bio-based nylon auxiliaries, belonging to the field of enzyme-catalyzed synthesis technology. Background Technology

[0002] Nylon, also known as polyamide resin (PA), is lightweight, non-toxic, possesses excellent mechanical strength, and exhibits strong wear and corrosion resistance. It is widely used in machinery, instrumentation, chemical, and automotive industries, and can also replace metals such as copper in the manufacture of gears, bearings, pump impellers, and other parts. Polyamide resin, after being melted and spun into fibers, can be used as synthetic fibers or medical sutures. In actual production, because the polymer backbone of nylon contains repeating amide groups (-NH-CO-), which are highly polar and chromophores, it is easily affected by the external environment, leading to the breakage of the macromolecular backbone and consequently affecting the various properties and color of nylon products. Therefore, during the processing and production of nylon, chemical additives are needed to improve the product performance and extend its service life.

[0003] The bio-based nylon auxiliary agent N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)2,5-furandicarboxamide involved in this invention is a novel nylon auxiliary agent. This auxiliary agent molecule contains multiple heteroatoms such as nitrogen and oxygen, which can effectively bind to the nylon backbone through intermolecular hydrogen bonds, thereby effectively improving the processing stability of the nylon melt, enabling nylon to maintain long-term thermal and light stability, improving its dyeing performance, enhancing the light fastness of nylon fibers, and extending the service life of nylon. The bio-based nylon auxiliary agent is a compound having the structural formula shown in Formula I;

[0004]

[0005] The traditional synthesis method for this product uses furanyl chloride and tetramethylpiperidineamine as raw materials. The advantage of this method is that the functional groups of the acyl chloride are highly reactive, readily reacting with the amino groups of tetramethylpiperidineamine to obtain the target nylon additive. Its disadvantages are that the acyl chloride is easily hydrolyzed, making it difficult to store stably. The reaction needs to be carried out continuously under anhydrous conditions, and after the reaction, it requires quenching with alkali and post-treatment, resulting in a complex purification process and the generation of large amounts of wastewater.

[0006]

[0007] In recent years, patent reports have described synthetic methods for preparing this nylon additive using dialkyl furanate and tetramethylpiperidineamine as raw materials. These methods often require high temperatures and the addition of metal alkoxide catalysts (e.g., sodium methoxide, patents CN105452243A and CN107109053A). These preparation methods are demanding and pose safety and environmental concerns. Summary of the Invention

[0008] To address the shortcomings and deficiencies of existing technologies, this invention provides an enzymatically catalytic preparation method for the nylon additive N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)2,5-furandicarboxamide. Using dialkyl furanate, a bio-based small molecule compound derived from biomass resources, as the starting material, the method reacts with tetramethylpiperidinylamine in an organic solvent at a relatively low reaction temperature under the catalysis of Candida antarctica lipase B. This method can efficiently and efficiently generate the target product in high yield, and the post-processing is simple and easy to operate. This method is green and safe, avoiding dangerous and environmentally unfriendly factors such as high temperatures, metal catalysts, and alkalis, and is safe and easy to operate.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: using dialkyl furanate and tetramethylpiperidineamine as raw materials, the target product is prepared by reacting in an organic solvent at a relatively low reaction temperature under the catalysis of Candida antarctica lipase B.

[0010] In a specific embodiment, the reaction conditions are as follows: reaction temperature is 30℃~45℃; reaction time is 1h~24h; the organic solvent is one or more of the following: methyl tert-butyl ether, diethyl ether, diisopropyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, acetone, dichloroethane, and n-hexane; and the enzyme catalyst is Candida antarctica lipase B.

[0011] In a specific embodiment, the mass ratio of the enzyme catalyst to the raw material dialkyl furanate is 1:(1-5); the molar ratio of the raw material dialkyl furanate to tetramethylpiperidineamine is 1:(2.5-5); and the dialkyl furanate is dimethyl furanate or diethyl furanate.

[0012] The method described in this invention also includes necessary post-treatment of the reaction solution: the post-treatment step of this invention is as follows: after the reaction is completed, the reaction mixture is filtered, the solid separation is washed with water, the filtrate is collected, and the filtrate is concentrated to obtain the target product.

[0013] The beneficial effects that this application can produce include:

[0014] 1. The method for preparing bio-based nylon adjuvant N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)2,5-furandicarboxamide catalyzed by Candida antarctica lipase B disclosed in this invention does not involve high-risk or toxic reagents such as metal catalysts or alkalis.

[0015] 2. This method does not involve high temperature conditions; the reaction temperature is 30℃~45℃, which is mild and safe, and has low equipment requirements.

[0016] 3. The product obtained by this method can achieve a purity of over 99% and a yield of over 95% on a gas chromatograph. Attached Figure Description

[0017] Figure 1 shows the high-resolution mass spectrometry of the bio-based nylon additive prepared using Example 3 of the present invention, proving that the target nylon additive has been obtained. Detailed Implementation

[0018] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0019] Unless otherwise specified, the raw materials and enzyme catalysts used in the embodiments of this application (the commercial CAS number of the enzyme catalyst is: 9001-62-1; the raw materials dimethyl furanate and diethyl furanate were both purchased from Zhejiang Tangneng Technology Co., Ltd.) were all purchased through commercial channels.

[0020] Example 1

[0021] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0022]

[0023] Tetramethylpiperidineamine (2.5 equivalents) was added to a 1M mixture of diisopropyl ether (184 mg, 1 equivalent) and dimethyl furanate (184 mL), followed by the addition of *Candida antarcticis* lipase B (CAL B) (73.5 mg). The reaction was continued at 45°C for 2 hours. After the dimethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of dimethyl furanate was calculated to be 95%, and the purity was 99.8% as determined by gas chromatography (GC).

[0024] Example 2

[0025] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0026] Tetramethylpiperidineamine (4 equivalents) was added to a 1M mixture of diisopropyl ether (184 mg, 1 equivalent) and dimethyl furanate (184 mL), followed by the addition of *Candida antarcticis* lipase B (CAL B) (73.5 mg). The reaction was continued at 45°C for 2 hours. After the dimethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of dimethyl furanate was calculated to be 98%, and the purity was 99.9% as determined by gas chromatography (GC).

[0027] Example 3

[0028] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0029] Tetramethylpiperidineamine (4 equivalents) was added to a 1M mixture of diisopropyl ether (184 mg, 1 equivalent) and dimethyl furanate (184 mL), followed by the addition of *Candida antarcticis* lipase B (CAL B) (61 mg). The reaction was continued at 45°C for 2 hours. After the dimethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of dimethyl furanate was calculated to be 97%, and the purity was 99.9% as determined by gas chromatography (GC).

[0030] Example 4

[0031] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0032] Tetramethylpiperidineamine (4 equivalents) was added to a 1M mixture of diisopropyl ether (184 mg, 1 equivalent) and dimethyl furanate (184 mL), followed by the addition of *Candida antarcticis* lipase B (CAL B) (73.5 mg). The reaction was continued at 30°C for 2 hours. After the dimethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of dimethyl furanate was calculated to be 95%, and the purity was 99.8% as determined by gas chromatography (GC).

[0033] Example 5

[0034] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0035] Tetramethylpiperidineamine (4 equivalents) was added to a 1M mixture of dimethyl furanate (184 mg, 1 equivalent) and tetrahydrofuran (184 mL), followed by the addition of *Candida antarcticis* lipase B (CAL B) (73.5 mg). The reaction was continued at 45°C for 2 hours. After the dimethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of dimethyl furanate was calculated to be 96%, and the purity was 99.9% as determined by gas chromatography (GC).

[0036] Example 6

[0037] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0038]

[0039] Tetramethylpiperidineamine (4 equivalents) was added to a 1M mixture of diethyl furanate (184 mg, 1 equivalent) and toluene (184 mL), followed by the addition of *Candida antarcticis* lipase B (CAL B) (73.5 mg). The reaction was continued at 45°C for 2 hours. After the diethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of dimethyl furanate was calculated to be 95%, and the purity was 99.4% as determined by gas chromatography (GC).

[0040] Example 7

[0041] The preparation method of the enzyme-catalyzed bio-based nylon adjuvant in this embodiment is as follows:

[0042] Tetramethylpiperidineamine (4 equivalents) was added to a 1M mixture of diisopropyl ether (212 mL) and diethyl furanate (212 mg, 1 equivalent), followed by the addition of *Candida antarcticis* lipase B (CAL B) (42.4 mg). The reaction was continued at 45°C for 24 hours. After the diethyl furanate reactant disappeared, the reaction mixture was filtered, the solids were washed with water, the filtrate was collected, and the filtrate was concentrated to obtain the target product. The yield of diethyl furanate was 98%, and the purity was 99.8% as determined by gas chromatography (GC).

[0043] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing an enzyme-catalyzed bio-based nylon adjuvant, characterized in that: Using dialkyl furanate and tetramethylpiperidinamine as raw materials, the reaction was carried out in an organic solvent at a relatively low reaction temperature under the catalysis of an enzyme catalyst. After the reaction, the reaction mixture was post-treated to obtain the target product, bio-based nylon auxiliary agent N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)2,5-furandicarboxamide. The enzyme catalyst was Candida antarcticis lipase B. The dialkyl furanate was dimethyl furanate or diethyl furanate. The reaction conditions were: reaction temperature of 30℃~45℃; reaction time of 1h~24h.

2. The preparation method according to claim 1, characterized in that, The organic solvent is one or more selected from methyl tert-butyl ether, diethyl ether, diisopropyl ether, tetrahydrofuran, 1,4-dioxane, toluene, acetonitrile, acetone, dichloroethane, and n-hexane.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the enzyme catalyst to the raw material dialkyl furanate is 1:(2.5~5).

4. The preparation method according to claim 1, characterized in that, The molar ratio of the raw material, dialkyl furanate, to tetramethylpiperidineamine is 1:(1~5).

5. The preparation method according to claim 1, characterized in that, After the reaction is complete, filter the reaction mixture, wash the solids with water, collect the filtrate, concentrate the filtrate, and you can get the target product.

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