A preparation method and application of pentamethylenediamine adipate

Abstract

The present invention provides a preparation method and application of pentamethylenediamine adipate. The preparation method comprises the following steps: A) decarboxylating L-lysine under the action of a catalyst; B) reacting the reaction mixture obtained in step A) with adipic acid in situ to obtain pentamethylenediamine adipate. The present invention uses cheap L-lysine as a raw material, and in the presence of a catalyst, a chemical decarboxylation reaction occurs to obtain a reaction mixture including pentamethylenediamine, and no further purification and post-treatment are required. Pentamethylenediamine adipate can be obtained by directly reacting with adipic acid. The steps are simple, no complicated post-treatment operations are required, it is easy to implement, and it is environmentally friendly and suitable for large-scale production. Among them, the yield of pentamethylenediamine adipate can reach up to 82% and the purity can reach 99%.

Description

Technical Field

[0001] The invention belongs to the technical field of bio-based materials, and specifically relates to a preparation method of pentamethylenediamine adipate and application thereof. Background Art

[0002] Nylon is irreplaceable in chemical fibers due to its good resilience, light weight, high mechanical strength, antistatic and easy dyeing. Among them, nylon 6 and nylon 66 have the largest output, accounting for about 90% of the total nylon output. A report shows that the global nylon 6 and nylon 66 market size will reach 197.592 billion yuan in 2022, and will continue to grow at an average growth rate of 6.22%. However, the raw materials for the production of nylon are currently mainly fossil resources. With the depletion of fossil resources and the increasing severity of air pollution, the development of bio-based materials is of great significance to green environmental protection and sustainable development.

[0003] Nylon 56 (polypentamethylenediamine adipate) is a bio-based material, which is polymerized from bio-based pentamethylenediamine and petroleum-based adipic acid. It has similar performance to nylon 66 products, and has the advantages of high strength, wear resistance, flame retardancy, moisture absorption and excellent resilience, and has gradually attracted people's attention.

[0004] At present, nylon 56 is generally prepared by first preparing pure 1,5-pentanediamine (also known as "pentanediamine") product, and then salifying or directly polymerizing it with adipic acid. However, the preparation method of pentamethylenediamine is mainly prepared by enzymatic decarboxylation of lysine through bioengineering technology or chemical preparation. Among them, the enzymatic method has the problems of cumbersome fermentation process, difficulty in purifying 1,5-pentanediamine, difficulty in separating the products after fermentation, low productivity and high industrial cost, which greatly restricts the production of nylon 56. Similarly, the chemical method for preparing pentamethylenediamine generally first obtains pentamethylenediamine hydrochloride, and then undergoes cumbersome purification operations to obtain pure pentamethylenediamine products. Therefore, the current method for preparing nylon 56 has the problems of high cost and complicated steps, which is not conducive to large-scale production. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a preparation method of pentamethylenediamine adipate and its application. The preparation method is low in cost, simple to operate, environmentally friendly, and suitable for large-scale production.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for preparing pentamethylenediamine adipate, comprising the following steps:

[0008] A) L-Lysine is subjected to a decarboxylation reaction under the action of a catalyst;

[0009] B) reacting the reaction mixture obtained in step A) with adipic acid in situ to obtain pentamethylenediamine adipate.

[0010] Preferably, the temperature of the decarboxylation reaction is 100-200° C., and the time is 0.5-48 h.

[0011] Preferably, the temperature of the in-situ reaction is 30-80° C., and the time is 0.5-48 h.

[0012] Preferably, the catalyst is selected from any one or more of acetophenone, 2-bromoacetophenone, 4-bromoacetophenone, 4-methyl-3-pentene-2-one, 2,4-pentanedione, 2,6-dimethyl-2,5-heptadien-4-one, methylcyclohexenone, isophorone, 3-phenyl-2-cyclohexene-1-one, R-carvone, cyclohexanone, 1-acetyl-1-cyclohexene, 2-acetylanisole, 1-tetralone, 1-indanone, cyclododecanone, indole-3-carboxaldehyde or pyrrole-2-carboxaldehyde.

[0013] Preferably, the molar ratio of the catalyst to L-lysine is (0.05-10):1.

[0014] Preferably, the molar ratio of adipic acid to L-lysine is (0.5-2):1.

[0015] Preferably, the decarboxylation reaction is carried out in the presence of a solvent.

[0016] Preferably, the solvent is selected from any one or more of dimethyl sulfoxide, N,N-dimethylacetamide, N-methylpyrrolidone, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, cyclohexanol or sulfolane.

[0017] In a second aspect, the present invention provides a bio-based nylon 56 obtained by polymerizing pentamethylenediamine adipate obtained in the above technical solution.

[0018] In a third aspect, the present invention provides a textile comprising the bio-based nylon 56 involved in the above technical solution.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a method for preparing 1,5-pentanediamine by chemical decarboxylation of L-lysine through organic catalysis, and further reacting the L-lysine with adipic acid to prepare pentamethylenediamine adipate. The method first uses L-lysine with serious overcapacity and low price as a raw material, and in the presence of a catalyst, chemically decarboxylates to form an amide intermediate, and then deprotects to obtain a mixture of 1,5-pentanediamine. The present invention does not require post-treatment of the mixture of 1,5-pentanediamine to obtain a pure pentamethylenediamine product, but directly mixes the mixture of 1,5-pentanediamine with adipic acid to react in situ to obtain pentamethylenediamine adipate, and the pentamethylenediamine adipate can be polymerized to obtain bio-based nylon 56. Compared with the prior art of preparing pure 1,5-pentanediamine products by enzyme-catalyzed decarboxylation or chemical decarboxylation, the method provided by the present invention has low economic cost and simple steps, and does not require complicated post-processing operations to obtain pure pentamethylenediamine products. It is easy to implement and environmentally friendly. The prepared pentamethylenediamine adipate has a high yield of up to 82%, and is suitable for large-scale production. It has important practical significance for the preparation of bio-based nylon 56 salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the H NMR spectrum of pentamethylenediamine adipate obtained in Example 1;

[0022] Figure 2 This is the NMR carbon spectrum of pentamethylenediamine adipate obtained in Example 1. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the prior art, bio-based nylon 56 salt is generally prepared by first preparing a pure 1,5-pentanediamine product, and then subjecting it to salt polymerization or direct polymerization with adipic acid. Pure 1,5-pentanediamine products are generally prepared by enzyme-catalyzed decarboxylation or chemical methods, but there are problems of high cost, low yield and cumbersome steps. Based on this, the present invention provides a method for preparing pentamethylenediamine adipate, which method does not require the preparation of a pure pentamethylenediamine product, but directly reacts a mixture including pentamethylenediamine with adipic acid in situ to obtain a target product, specifically comprising the following steps:

[0025] A) L-Lysine is subjected to a decarboxylation reaction under the action of a catalyst;

[0026] B) reacting the reaction mixture obtained in step A) with adipic acid in situ to obtain pentamethylenediamine adipate.

[0027] According to the present invention, L-lysine is first subjected to a decarboxylation reaction under the action of a catalyst to obtain a reaction mixture comprising pentamethylenediamine. The present invention has no particular restrictions on L-lysine, and it can be a general commercial product. The catalyst is preferably selected from any one or more of acetophenone, 2-bromoacetophenone, 4-bromoacetophenone, 4-methyl-3-pentene-2-one, 2,4-pentanedione, 2,6-dimethyl-2,5-heptadiene-4-one, methylcyclohexenone, isophorone, 3-phenyl-2-cyclohexene-1-one, R-carvone, cyclohexanone, 1-acetyl-1-cyclohexene, 2-acetylanisole, 1-tetralone, 1-indanone, cyclododecanone, indole-3-carboxaldehyde or pyrrole-2-carboxaldehyde, and more preferably any one or more of isophorone, 3-phenyl-2-cyclohexene-1-one, R-carvone or cyclohexanone. In some embodiments of the present invention, the molar ratio of the catalyst to L-lysine is preferably (0.05-10):1, which may be 0.05:1, 0.1:1, 0.5:1, 1:1, 3:1, 0.05:1, 5:1, 8:1 or 10:1, preferably (0.1-8):1, and decarboxylation reaction occurs after mixing. The temperature of the decarboxylation reaction is 100-200°C, preferably 120-180°C, more preferably 140-160°C, and the time is 0.5-48h, preferably 8-36h, more preferably 12-24h. In some embodiments of the present invention, the decarboxylation reaction is carried out in the presence of a solvent, that is, the catalyst and L-lysine are mixed with the solvent in the above ratio and decarboxylation reaction occurs, and the solvent is preferably selected from any one or more of dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, cyclohexanol or cyclohexane sulfone, and more preferably selected from any one or more of n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol or cyclohexanol. The amount of the solvent is based on the mass of lysine, and the specific amount ratio is 0.01 to 10 g / mL, preferably 0.1 to 5 g / mL, and more preferably 0.2 to 1 g / mL. In the present invention, the decarboxylation reaction is preferably carried out under stirring conditions.

[0028] After the decarboxylation reaction is completed, the obtained reaction mixture including pentamethylenediamine is reacted with adipic acid to obtain pentamethylenediamine adipate. The present invention has no particular restrictions on the source of adipic acid, and it can be a general commercial product. In the present invention, the amount of adipic acid used is based on L-lysine, and the molar ratio of adipic acid to L-lysine is (0.5-2):1, specifically 0.5:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.8:1 or 2:1, preferably (1-2):1. In some embodiments of the present invention, in order to avoid a small amount of reactant L-lysine remaining, after the decarboxylation reaction is completed, the obtained reaction mixture is preferably filtered to obtain a filtrate including pentamethylenediamine, and mixed with the first solvent to facilitate the subsequent experiments; at the same time, the adipic acid solid is dissolved in the second solvent. Wherein, the first solvent and the second solvent may be the same or different, and each is independently selected from any one or more of water, methanol, ethanol, acetonitrile, ethyl acetate, acetone, tetrahydrofuran or DMSO, preferably the same reagent is used for both, and in one embodiment of the present invention, the first solvent and the second solvent are preferably methanol. The present invention has no particular restrictions on the amount of the first solvent and the second solvent, and they can be added as needed. Then the solution of the filtrate containing pentamethylenediamine is mixed with the adipic acid solution, preferably the solution of the filtrate containing pentamethylenediamine is slowly added dropwise to the adipic acid solution, and reacted at 30 to 80°C for 0.5 to 48h, preferably at 50 to 80°C for 2 to 36h, more preferably at 50 to 60°C for 4 to 24h, and the reaction is preferably carried out under stirring. In some embodiments of the present invention, after the reaction is completed, the obtained reaction solution is preferably filtered while hot to prevent excess adipic acid from precipitating and affecting the yield of pentamethylenediamine adipate. After the filtration is completed, the precipitate is taken and washed to remove impurities on the surface. The washing can be carried out using an alcohol reagent, and methanol is preferred in the present invention. After the washing is completed, it is preferred that a drying treatment is also included. The drying can be performed in a drying method well known to those skilled in the art. The present invention preferably performs vacuum drying at 50-70°C for 4-48 hours, and more preferably performs vacuum drying at 60°C for 4-48 hours.

[0029] The preparation method of the pentamethylenediamine adipate provided by the present invention uses L-lysine, which has a serious overcapacity and a low price, as a raw material, and undergoes a chemical decarboxylation reaction in the presence of a catalyst to obtain a reaction mixture including pentamethylenediamine. The reaction mixture can be directly reacted with adipic acid to obtain pentamethylenediamine adipate without further purification or post-treatment. The steps are simple, and complicated post-treatment operations are not required. The method is easy to implement, is environmentally friendly, and is suitable for large-scale production.

[0030] The above preparation method is used to obtain pentamethylenediamine adipate. According to calculation, the yield can reach up to 82% and the purity can reach 99%, indicating that the above preparation method provided by the present invention can achieve high-purity and high-yield production of pentamethylenediamine adipate.

[0031] The pentamethylenediamine adipate prepared by the present invention can be used as a monomer to obtain bio-based nylon 56 after polymerization. The present invention has no special restrictions on the polymerization process, and it can be carried out according to technical means familiar to those skilled in the art.

[0032] Bio-based nylon 56 can be applied in many fields, such as being prepared into textiles, filter membranes or automotive engineering materials. Based on this, the present invention also provides a textile comprising the above-mentioned bio-based nylon 56.

[0033] In order to further illustrate the present invention, the following examples are used to provide a detailed description. The experimental raw materials used in the following examples of the present invention can be purchased from the market and are generally commercially available products; or prepared according to conventional technical means well known to those skilled in the art. Among them, acetophenone, cyclohexanone, R-carvone, 4-bromoacetophenone, 3-phenyl-2-cyclohexene-1-one, 2,4-pentanedione and isophorone used in the following examples are all chemically pure reagents.

[0034] The yield in the following examples is the mass of pentamethylenediamine adipate actually obtained / the mass of pentamethylenediamine adipate obtained by the theoretical reaction of pentamethylenediamine with adipic acid after all lysine is decarboxylated.

[0035] Example 1

[0036] Under nitrogen atmosphere, 0.73 g L-lysine and 1 mL acetophenone were added to 3 mL DMSO and stirred at 160 ° C for 8 h. After the reaction, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73 g adipic acid were added to two 30 mL anhydrous methanol portions. The methanol solution added to the reaction solution was slowly added to the methanol solution containing adipic acid and stirred at 40 ° C for 2 h. The mixture was filtered while hot, washed with methanol, and dried under vacuum at 60 ° C for 8 h to obtain pentamethylenediamine adipate (0.91 g, yield 73%, purity 99%). 1 HNMR(D2O,300MHz)δ2.94(t,4H),2.12(t,4H),1.56-1.72(m,4H),1.48(t,4H),1.31-1.43(m,2H). 13 CNMR(D2O,100MHz)δ183.68,39.11,37.44,26.24,25.86,22.66.

[0037] The H NMR spectrum and C NMR spectrum of pentamethylenediamine adipate obtained in Example 1 are as follows: Figure 1and 2 As shown, it was shown that the product was pentamethylenediamine adipate.

[0038] Example 2

[0039] Under nitrogen atmosphere, 0.73g L-lysine and 0.4mL cyclohexanone were added to 3mL DMAc and stirred at 160°C for 8h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL anhydrous methanol portions. The methanol solution added to the reaction solution was slowly added to a methanol solution containing adipic acid and stirred at 40°C for 4h. The mixture was filtered while hot, washed with methanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (0.88g, yield 71%, purity 99%). The NMR results were consistent with those in Example 1.

[0040] Example 3

[0041] Under nitrogen atmosphere, 0.73g L-lysine and 0.4mL R-carvone were added to 5mL cyclohexanol and stirred at 160°C for 8h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL anhydrous methanol portions. The methanol solution added to the reaction solution was slowly added to a methanol solution containing adipic acid and stirred at 40°C for 4h. The mixture was filtered while hot, washed with methanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (0.97g, yield 78%, purity 99%). The NMR results were consistent with those in Example 1.

[0042] Example 4

[0043] Under nitrogen atmosphere, 0.73g L-lysine and 0.4mL 4-bromoacetophenone were added to 6mL NMP and stirred at 160°C for 12h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL portions of anhydrous ethanol. The ethanol solution added dropwise to the reaction solution was slowly added dropwise to an ethanol solution containing adipic acid and stirred for 2h at 60°C. The mixture was filtered while hot, washed with ethanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (0.86g, yield 69%, purity 99%). The NMR results were consistent with those in Example 1.

[0044] Example 5

[0045] Under nitrogen atmosphere, 0.73g L-lysine and 0.4mL 3-phenyl-2-cyclohexene-1-one were added to 6mL n-butanol and stirred at 160°C for 12h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL portions of anhydrous ethanol. The ethanol solution dripped into the reaction solution was slowly added dropwise to an ethanol solution containing adipic acid and stirred at 60°C for 8h. The mixture was filtered while hot, washed with ethanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (0.98g, yield 79%, purity 99%). The NMR result was consistent with that in Example 1.

[0046] Example 6

[0047] Under nitrogen atmosphere, 0.73g L-lysine and 1.5mL acetophenone were added to 6mL DMAc and stirred at 130°C for 24h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL portions of anhydrous ethanol. The ethanol solution added to the reaction solution was slowly added dropwise to an ethanol solution containing adipic acid and stirred at 60°C for 8h. The mixture was filtered while hot, washed with ethanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (0.89g, yield 72%, purity 99%). The NMR results were consistent with those in Example 1.

[0048] Example 7

[0049] Under nitrogen atmosphere, 0.73g L-lysine and 1.5mL 2,4-pentanedione were added to 6mL n-propanol and stirred at 130°C for 24h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL portions of anhydrous ethanol. The ethanol solution added dropwise to the reaction solution was slowly added dropwise to an ethanol solution containing adipic acid and stirred at 60°C for 8h. The mixture was filtered while hot, washed with ethanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (1.01g, yield 81%, purity 99%). The NMR results were consistent with those in Example 1.

[0050] Example 8

[0051] Under nitrogen atmosphere, 0.73g L-lysine and 0.3mL isophorone were added to 6mL cyclohexanol and stirred at 130°C for 4h. After the reaction was completed, the mixture was cooled to room temperature and filtered to obtain a filtrate. The filtrate and 0.73g adipic acid were added to two 30mL portions of anhydrous ethanol. The ethanol solution added dropwise to the reaction solution was slowly added dropwise to an ethanol solution containing adipic acid and stirred at 60°C for 8h. The mixture was filtered while hot, washed with ethanol, and dried under vacuum at 60°C for 8h to obtain pentamethylenediamine adipate (1.02g, yield 82%, purity 99%). The NMR results were consistent with those in Example 1.

[0052] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing pentamethylenediamine adipate, characterized in that: The following steps are involved: A) Decarboxylation of L-lysine under the action of a catalyst; B) reacting the reaction mixture obtained in step A) with adipic acid in situ to obtain pentamethylenediamine adipate; The decarboxylation reaction is carried out in the presence of a solvent; The solvent is selected from any one or more of n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol or cyclohexanol; The catalyst is selected from any one or more of acetophenone, 2-bromoacetophenone, 4-bromoacetophenone, 4-methyl-3-pentene-2-one, 2,4-pentanedione, 2,6-dimethyl-2,5-heptadien-4-one, methylcyclohexenone, isophorone, 3-phenyl-2-cyclohexene-1-one, R-carvone, cyclohexanone, 1-acetyl-1-cyclohexene, 2-acetylanisole, 1-tetralone, 1-indanone, cyclododecanone, indole-3-carboxaldehyde or pyrrole-2-carboxaldehyde; The temperature of the decarboxylation reaction is 100 to 200 o C, time is 4~48 hours; The temperature of the in-situ reaction is 30 to 80 o C, time is 2~48 h.

2. The preparation method according to claim 1, characterized in that: The molar ratio of the catalyst to L-lysine is (0.05-10):

1.

3. The preparation method according to claim 1, characterized in that: The molar ratio of adipic acid to L-lysine is (0.5-2):1.

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