A kind of furanyl nylon salt and preparation method thereof

Abstract

The present invention belongs to the technical field of polymer materials, and specifically discloses a furanyl nylon salt, and also discloses its preparation method and application. The furanyl nylon salt provided by the present invention has a structural formula as shown in formula (I), and the furanyl nylon salt is prepared using 2,5-furandicarboxylic acid and an aliphatic diamine with water as a solvent, and then decolorized with activated carbon, distilled under reduced pressure, and dried to obtain a polymerization-grade furanyl nylon salt. The furanyl nylon salt has stable properties, high purity, and good appearance quality, and can directly prepare various furanyl polyamide materials by melt polymerization. It also has excellent heat resistance and mechanical properties and can be widely used in related fields such as chemical fibers and engineering plastics.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and particularly relates to a furanyl nylon salt and a preparation method thereof. Background Art

[0002] Polyamide, commonly known as nylon, is a general term for thermoplastic resins containing repeating amide groups "-[NHCO]-" on the main chain of the molecule. Nylon has good comprehensive properties, including good mechanical properties, heat resistance, wear resistance, chemical resistance and self-lubrication, and has a low coefficient of friction, a certain degree of flame retardancy, and is easy to process. It is currently widely used in the fields of synthetic fibers and engineering plastics. There are many varieties of nylon, including aliphatic polyamides, semi-aromatic polyamides, and fully aromatic polyamides such as aramid, among many new varieties. Aliphatic polyamides generally have low mechanical strength and heat resistance, and their application is subject to certain restrictions; the main monomers of semi-aromatic and aramid are derived from petroleum-based resources, and do not have the advantages of low carbon environmental protection and sustainable development.

[0003] In addition, the synthesis of polyamide is through the dehydration condensation of dibasic acid and diamine to form linear macromolecular segments, wherein the mass balance of acid and amine affects the molecular weight growth. Therefore, the dibasic acid and diamine are generally first reacted to form salts, that is, first obtain nylon salts, and then use the nylon salts for polycondensation to prepare high molecular weight polyamide polymers. In the prior art, the synthesis of nylon salts usually adopts a solvent method, that is, first dissolving the acid and amine in a solvent respectively, then mixing them together for neutralization reaction, determining the reaction end point by pH value, and then separating, purifying, and drying to obtain nylon salts. When water is used as the solvent, during the salt collection process, the nylon salts are generally cooled and precipitated in the solvent system by cooling, and then filtered and separated. It is often found that impurities and nylon salts in the system cannot be effectively separated, resulting in high nylon salt impurities and low yield. When an organic solvent is used as the reaction solvent, due to the limitations of existing pH measurement equipment, the end point of the neutralization reaction cannot be effectively controlled in the organic system, resulting in an increase in the free acid and free amine content in the nylon salt. At the same time, the organic system is not environmentally friendly and has high costs.

[0004] Based on the above reasons, the present invention aims to provide a furanyl nylon salt, which, on the one hand, meets the needs of low-carbon environmental protection and sustainable development, and on the other hand, improves the purity of the obtained nylon salt by adopting a suitable preparation method, thereby providing a guarantee for the further preparation of high-quality polyamide polymers. Summary of the Invention

[0005] The purpose of the present invention is to provide a furanyl nylon salt, which uses 2,5-furandicarboxylic acid (FDCA) as a dibasic acid raw material to meet the needs of low-carbon environmental protection and sustainable development.

[0006] The present invention also aims to provide a method for preparing a furanyl nylon salt, by which a high-purity nylon salt product can be obtained, thus providing a guarantee for further preparing high-quality polyamide polymers.

[0007] To achieve the above objectives, the present invention adopts the following technical solutions.

[0008] In a first aspect, the present invention provides a furanyl nylon salt, the structural formula of which is shown in formula (I):

[0009]

[0010] Here, n represents an integer from 2 to 14.

[0011] As an embodiment of the present invention, in formula (I), n represents an integer of 2 to 12.

[0012] As a preferred embodiment of the present invention, in formula (I), n represents an integer of 2, 3, 4, 5, 6, 8, 10, or 12.

[0013] In a second aspect, the present invention provides a method for preparing a furanyl nylon salt, comprising the steps of:

[0014] (1) mixing 2,5-furandicarboxylic acid, an aliphatic diamine, pyridine, and a solvent to obtain a salt-forming reaction material;

[0015] (2) Under the protection of an inert gas, the salt-forming reaction material undergoes a salt-forming reaction until the reaction liquid becomes clear, and then the pH value of the reaction system is adjusted to 7.4 to 8.0 with the aliphatic diamine, and then the reaction is continued for 1 to 3 hours to obtain a furanyl nylon salt solution;

[0016] (3) adding activated carbon to the furanyl nylon salt solution for treatment, and then separating the activated carbon to obtain a purified furanyl nylon salt solution;

[0017] (4) The solvent in the purified furanyl nylon salt solution is evaporated and then dried to obtain a furanyl nylon salt product.

[0018] As an embodiment of the present invention, in step (1), the aliphatic diamine comprises the structural formula: wherein n represents an integer of 2 to 14, preferably n represents an integer of 2 to 12, and further preferably, n represents an integer of 2, 3, 4, 5, 6, 8, 10 or 12.

[0019] As a preferred embodiment of the present invention, in step (1), the aliphatic diamine is selected from any one or more of ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine.

[0020] As an embodiment of the present invention, in step (1), the molar ratio of the 2,5-furandicarboxylic acid and the aliphatic diamine is 1:1.

[0021] As an embodiment of the present invention, in step (1), the amount of pyridine used is 1% to 10% of the mass of the 2,5-furandicarboxylic acid.

[0022] Preferably, in step (1), the amount of pyridine used is 1% to 3% of the mass of the 2,5-furandicarboxylic acid; further preferably, in step (1), the amount of pyridine used is 1.8% to 2.0% of the mass of the 2,5-furandicarboxylic acid. The present invention surprisingly discovered that adding a small amount of pyridine to the reaction mass effectively increases the solubility of 2,5-furandicarboxylic acid in water, thereby increasing the mass concentration of nylon salt in the reaction system and significantly improving production efficiency.

[0023] As an embodiment of the present invention, in step (1), the solvent is deionized water.

[0024] Preferably, the amount of deionized water is added to control the theoretical mass percentage concentration of furanyl nylon salt in the salt-forming reaction material to be 20% to 80%. Further preferably, the amount of deionized water is added to control the theoretical mass percentage concentration of furanyl nylon salt in the salt-forming reaction material to be 40% to 60%.

[0025] The theoretical mass percentage concentration of the furanyl nylon salt in the salt-forming reaction material refers to the mass percentage concentration of the furanyl nylon salt in the salt-forming reaction material calculated based on the complete reaction of the 2,5-furandicarboxylic acid and the aliphatic diamine to form the furanyl nylon salt.

[0026] As an embodiment of the present invention, in step (2), the reaction temperature of the salt-forming reaction is 50 to 90°C, preferably 60 to 80°C.

[0027] As an embodiment of the present invention, in step (2), the salt-forming reaction is carried out under stirring, preferably at a stirring speed of 80 to 200 r / min.

[0028] As an embodiment of the present invention, in step (2), the aliphatic diamine is first prepared into an aqueous solution and then used to adjust the pH value; more preferably, the mass percentage concentration of the aliphatic diamine aqueous solution is 50% to 80%.

[0029] As an embodiment of the present invention, in step (3), the amount of activated carbon added is 1% to 3% of the mass of the furanyl nylon salt solution.

[0030] As an embodiment of the present invention, in step (3), the adding of activated carbon for treatment is to add activated carbon for ultrasonic treatment for 10 to 30 minutes.

[0031] As an embodiment of the present invention, in step (3), the activated carbon is separated by microporous membrane filtration, the pressure is controlled to be -0.1Mpa to -0.05Mpa, and the microporous membrane specification adopts aqueous phase and pore size of 0.22 to 1.0μm.

[0032] As an embodiment of the present invention, in step (4), the solvent is evaporated using a rotary evaporator, and the water bath temperature is controlled at 50-70°C, preferably 58-62°C, and more preferably 60°C.

[0033] As an embodiment of the present invention, in step (4), the drying is carried out by forced air drying, the drying temperature is 50 to 70° C., and the drying time is 4 to 8 hours.

[0034] As an embodiment of the present invention, in step (4), the chromaticity L value of the furanyl nylon salt product is ≥92 and the b value is ≤3.

[0035] In a third aspect, the present invention provides an application of a furanyl nylon salt, and its application in the preparation of polyamide polymers.

[0036] The furanyl nylon salt provided by the present invention uses 2,5-furandicarboxylic acid (FDCA) as the dibasic acid raw material for its preparation. 2,5-furandicarboxylic acid is a stable furan derivative derived from biomass. It is a widely available bio-based compound and can be produced from biomass such as fruit shells and straw, meeting the needs of low-carbon environmental protection and sustainable development. FDCA also has a structure similar to that of terephthalic acid (PTA), both possessing a rigid cyclic conjugated system and two carboxyl groups. Therefore, nylon salts prepared from FDCA and diamines can be further prepared into polyamide polymer materials with excellent heat resistance and high mechanical strength.

[0037] The present invention provides a method for preparing a furanyl nylon salt, which uses 2,5-furandicarboxylic acid and an aliphatic diamine with water as a solvent for preparation, followed by decolorization with activated carbon, vacuum distillation, and drying to obtain a polymerization-grade furanyl nylon salt. The furanyl nylon salt has stable properties, high purity, and good appearance quality. The furanyl nylon salt can be directly used to prepare various furan-based polyamide materials through melt polymerization, and has excellent heat resistance and mechanical properties. It can be widely used in related fields such as chemical fibers and engineering plastics. The method for preparing the furanyl nylon salt can also be applied to the synthesis of other aliphatic, aromatic, or semi-aromatic nylon salts. The method has little environmental pollution, and the product has high purity and good appearance quality.

[0038] The present invention has the following beneficial effects:

[0039] (1) 2,5-Furandicarboxylic acid is used as the main reaction monomer. It has a rigid cyclic conjugated molecular structure similar to terephthalic acid (PTA), which can ensure that the polymer has high mechanical strength and heat resistance.

[0040] (2) 2,5-Furandicarboxylic acid is derived from biomass and has the characteristics of low-carbon sustainable development. It can be used with bio-based diamines to develop completely bio-based polyamides, thus getting rid of dependence on petroleum resources;

[0041] (3) Deionized water is used as the reaction solvent, which has little environmental pollution, simple separation process and low cost, and has the advantages of being green, environmentally friendly, simple and safe;

[0042] (4) The activated carbon and ultrasonic treatment process can remove impurities and decolorize the product, ensuring the purity and appearance quality of the furanyl nylon salt. The process is simple and easy to operate, and the product performance is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is an infrared spectrum of the furanyl nylon salt 2,5-furandicarboxylic acid pentamethylenediamine salt product obtained in Example 2 of the present invention;

[0044] Figure 2 This is a physical photo of the furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product obtained in Example 3 of the present invention;

[0045] Figure 3 This is an infrared spectrum of the furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product obtained in Example 3 of the present invention;

[0046] Figure 4 This is an infrared spectrum of the furanyl nylon salt 2,5-furandicarboxylic acid octanediamine salt product obtained in Example 4 of the present invention;

[0047] Figure 5This is the infrared spectrum of the furanyl nylon salt 2,5-furandicarboxylic acid decanediamine salt product obtained in Example 5 of the present invention. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is described in further detail below. It should be understood by those skilled in the art that the specific embodiments described are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0049] It should be noted that, unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available conventional products.

[0050] The furanyl nylon salt provided by the present invention has a structural formula as shown in formula (I):

[0051]

[0052] Here, n represents an integer of 2 to 14, and preferably n represents an integer of 2 to 12.

[0053] The preparation method of the furanyl nylon salt provided by the present invention comprises the steps of:

[0054] (1) mixing 2,5-furandicarboxylic acid, an aliphatic diamine, pyridine, and a solvent to obtain a salt-forming reaction material;

[0055] Wherein, 2,5-furandicarboxylic acid and aliphatic diamine are mixed in a molar ratio of 1:1; the aliphatic diamine is selected from any one or more of ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine;

[0056] The amount of pyridine is 1% to 10% of the mass of the 2,5-furandicarboxylic acid; the solvent is deionized water, and the amount of deionized water is added to control the theoretical mass percentage concentration of the furanyl nylon salt in the salt-forming reaction material to be 20% to 80%;

[0057] (2) Under the protection of inert gas, the salt-forming reaction material undergoes a salt-forming reaction at a reaction temperature of 50 to 90° C., the salt-forming reaction is carried out under stirring, and the stirring speed is 80 to 200 r / min; after the reaction liquid is clarified, the pH value of the reaction system is adjusted to 7.4 to 8.0 with an aqueous solution of an aliphatic diamine having a mass percentage concentration of 50% to 80%, and then the reaction is continued for 1 to 3 hours while maintaining the temperature to obtain a furanyl nylon salt solution;

[0058] (3) Activated carbon is added to the furanyl nylon salt solution for treatment, and the amount of activated carbon added is 1% to 3% of the mass of the furanyl nylon salt solution. After adding the activated carbon, ultrasonic treatment is performed for 10 to 30 minutes, and then the activated carbon is separated by microporous membrane filtration method. The pressure is controlled at -0.1 MPa to -0.05 MPa. The microporous membrane specification adopts aqueous phase and pore size of 0.22 μm to obtain a clear and transparent purified furanyl nylon salt solution;

[0059] (4) Purification of the furanyl nylon salt solution: The solvent is removed by evaporating the solution with a rotary evaporator, and the water bath temperature is controlled at 50-70°C. The solution is then dried with forced air at a temperature of 50-70°C for 4-8 hours to obtain a furanyl nylon salt product. The color L value of the furanyl nylon salt product is ≥92, and the b value is ≤3.

[0060] The following is a detailed description using specific examples.

[0061] Example 1

[0062] This embodiment provides a furanyl nylon salt, namely 2,5-furandicarboxylic acid butanediamine salt, the structural formula of which is shown below:

[0063]

[0064] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 88g of 1,4-butanediamine, 3g of pyridine, and 241g of deionized water are added to a double-layer glass reactor, and the theoretical mass percentage concentration of nylon salt in the reaction system is 50%; then, nitrogen is introduced to replace the air in the reactor, and the process is repeated three times; then, a circulating heat medium is turned on to heat and heat to 80°C, and stirring is started at the same time, and the speed is 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% mass percentage concentration of 1,4-butanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at a constant temperature of 80°C for 1h. After the constant temperature reaction is completed, the furanyl nylon salt solution is released, and activated carbon is added to the furanyl nylon salt solution for decolorization. The amount of activated carbon added is 1.0% of the mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, it is filtered and the activated carbon is separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. A rotary evaporator is used to remove water from the furanyl nylon salt solution. The water bath temperature is controlled at 60°C during the rotary evaporation process. After removing water, a furanyl nylon salt wet product is obtained. The wet product is dried by air blast at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid butanediamine salt product.

[0065] Example 2

[0066] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid pentamethylenediamine salt, the structural formula of which is shown below:

[0067]

[0068] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 102g of 1,5-pentanediamine, 3g of pyridine, and 255g of deionized water are added to a double-layer glass reactor, and the theoretical mass percentage concentration of nylon salt in the reaction system is 50%; then nitrogen is introduced to replace the air in the reactor, and the process is repeated three times; then a circulating heat medium is turned on to heat and heat to 80°C, and stirring is started at the same time, and the speed is 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 1,5-pentanediamine aqueous solution with a mass percentage concentration of 60% is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.5, and then the reaction is continued at a constant temperature of 80°C for 1h; After the reaction is completed, the furanyl nylon salt solution is released, and activated carbon is added to the furanyl nylon salt solution for decolorization. The amount of activated carbon added is 1.0% of the mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, the solution is filtered and the activated carbon is separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. The water in the furanyl nylon salt solution is removed by a rotary evaporator. The water bath temperature is controlled at 60° C. during the rotary evaporation process. After dehydration, a wet furanyl nylon salt product is obtained. The product is dried by blast drying at a drying temperature of 60° C. for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid pentamethylenediamine salt product, whose infrared spectrum is shown in FIG. Figure 1 shown.

[0069] Example 3

[0070] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt, the structural formula of which is shown below:

[0071]

[0072] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor, and the theoretical mass percentage concentration of nylon salt in the reaction system is 50%; then nitrogen is introduced to replace the air in the reactor, and the process is repeated three times; then the circulating heat medium is turned on to heat and heat to 80°C, and stirring is started at the same time, and the speed is 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 1,6-hexanediamine aqueous solution with a mass percentage concentration of 60% is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at a constant temperature of 80°C for 1h; After the reaction is completed, the furanyl nylon salt solution is released, and activated carbon is added to the furanyl nylon salt solution for decolorization. The amount of activated carbon added is 1.0% of the mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, the solution is filtered and the activated carbon is separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. The water in the furanyl nylon salt solution is removed by a rotary evaporator. The water bath temperature is controlled at 60°C during the rotary evaporation process. After dehydration, a wet product of furanyl nylon salt is obtained. The product is dried by blast drying at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product. The actual photo of the product is shown in FIG. Figure 2 As shown, the infrared spectrum of the product is shown in Figure 3 shown.

[0073] from Figure 2 It can be seen that the obtained furanyl nylon salt product has good hue. Figure 3 It can be seen from the infrared spectrum that in the range of 3300-3500cm -1 The stretching vibration peak of the secondary amine NH bond of the diamine monomer disappears, indicating that the diamine reaction is complete; 3500cm -1 There is no obvious carboxyl stretching vibration peak near the 1582cm -1 and 1638cm -1 A characteristic absorption peak formed by the association of carboxyl ions and amino ions appears at , indicating that 2,5-furandicarboxylic acid reacts with diamine to form the corresponding furanyl nylon salt.

[0074] Example 4

[0075] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid octanediamine salt, the structural formula of which is shown below:

[0076]

[0077] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 144g of 1,8-octanediamine, 3g of pyridine, and 297g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to perform a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,8-octanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.6, and then the reaction is continued at 80°C for 1h; after the isothermal reaction is completed, the furanyl nylon salt is released. nylon salt solution, adding activated carbon to the furanyl nylon salt solution for decolorization, the activated carbon addition amount being 1.0% of the mass of the furanyl nylon salt solution, ultrasonically treating for 15 minutes, filtering, and separating the activated carbon using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution; using a rotary evaporator to remove water from the furanyl nylon salt solution, controlling the water bath temperature at 60°C during the rotary evaporation process, and obtaining a wet furanyl nylon salt product after water removal, and drying by forced air at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid octanediamine salt product, whose infrared spectrum is shown in FIG. Figure 4 shown.

[0078] Example 5

[0079] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid decanediamine salt, the structural formula of which is shown below:

[0080]

[0081] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 172g of 1,10-decanediamine, 3g of pyridine, and 325g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to perform a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,10-decanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.5, and then the reaction is continued at 80°C for 1h; after the isothermal reaction is completed, furan is released. The invention discloses a method for preparing a furanyl nylon salt solution, wherein activated carbon is added to the furanyl nylon salt solution for decolorization, wherein the activated carbon addition amount is 1.0% of the mass of the furanyl nylon salt solution, and the method is ultrasonically treated for 15 minutes and then filtered. The activated carbon is separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution; a rotary evaporator is used to remove water from the furanyl nylon salt solution, and the water bath temperature is controlled to be 60°C during the rotary evaporation process. After dehydration, a wet furanyl nylon salt product is obtained, which is dried by blast drying at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid decanediamine salt product, whose infrared spectrum is shown in FIG. Figure 5 shown.

[0082] Example 6

[0083] The furanyl nylon salt provided in this embodiment is 2,5-furandicarboxylic acid hexamethylenediamine salt, which differs from Example 3 of the present invention in that the amount of deionized water used as the solvent is reduced when preparing the salt reaction material.

[0084] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 178g of deionized water are added to a double-layer glass reactor, and the theoretical mass percentage concentration of nylon salt in the reaction system is 60%; then nitrogen is introduced to replace the air in the reactor, and the process is repeated three times; then the circulating heat medium is turned on to heat and heat to 90°C, and stirring is started at the same time, and the speed is 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% mass percentage concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at a constant temperature of 90°C. 1h; after the constant temperature reaction is completed, the furanyl nylon salt solution is released, and activated carbon is added to the furanyl nylon salt solution for decolorization. The amount of activated carbon added is 1.0% of the mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, it is filtered and the activated carbon is separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution; water in the furanyl nylon salt solution is removed by a rotary evaporator, and the water bath temperature is controlled at 60°C during the rotary evaporation process. After dehydration, a furanyl nylon salt wet product is obtained, which is dried by forced air at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0085] Example 7

[0086] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0087] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to perform a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at 80°C for 2h; after the isothermal reaction is completed, the reaction mixture is placed in a cool, dry place. A furanyl nylon salt solution was obtained, and activated carbon was added to the furanyl nylon salt solution for decolorization. The activated carbon was added in an amount of 1.0% by mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, the solution was filtered and the activated carbon was separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. Water in the furanyl nylon salt solution was removed by a rotary evaporator. The water bath temperature was controlled at 60° C. during the rotary evaporation process. After water removal, a wet product of furanyl nylon salt was obtained. The wet product was dried by forced air at a drying temperature of 60° C. for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0088] Example 8

[0089] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0090] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at 80°C for 1h; after the isothermal reaction is completed, the reaction mixture is placed in a cool, dry place. A furanyl nylon salt solution was obtained, and activated carbon was added to the furanyl nylon salt solution for decolorization. The amount of activated carbon added was 1.5% of the mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, the solution was filtered and the activated carbon was separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. Water in the furanyl nylon salt solution was removed by a rotary evaporator. The water bath temperature was controlled at 60° C. during the rotary evaporation process. After water removal, a wet product of furanyl nylon salt was obtained. The wet product was dried by forced air at a drying temperature of 60° C. for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0091] Example 9

[0092] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0093] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at 80°C for 1h; after the isothermal reaction is completed, the reaction mixture is placed in a cool, dry place. A furanyl nylon salt solution was obtained, and activated carbon was added to the furanyl nylon salt solution for decolorization. The activated carbon addition amount was 0.5% of the mass of the furanyl nylon salt solution. After ultrasonic treatment for 15 minutes, the solution was filtered and the activated carbon was separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. Water in the furanyl nylon salt solution was removed by a rotary evaporator. The water bath temperature was controlled at 60° C. during the rotary evaporation process. After water removal, a wet product of furanyl nylon salt was obtained. The wet product was dried by forced air at a drying temperature of 60° C. for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0094] Example 10

[0095] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0096] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at 80°C for 1h; after the isothermal reaction is completed, the reaction mixture is placed in a cool, dry place. A furanyl nylon salt solution was obtained, and activated carbon was added to the furanyl nylon salt solution for decolorization. The activated carbon was added in an amount of 1.0% by mass of the furanyl nylon salt solution. After ultrasonic treatment for 20 minutes, the solution was filtered and the activated carbon was separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. Water in the furanyl nylon salt solution was removed by a rotary evaporator. The water bath temperature was controlled at 60° C. during the rotary evaporation process. After water removal, a wet product of furanyl nylon salt was obtained. The wet product was dried by forced air at a drying temperature of 60° C. for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0097] Example 11

[0098] This embodiment provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0099] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; a circulating heat medium is then turned on to heat and heat to 80°C, while stirring is started at a speed of 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at 80°C for 1h; after the isothermal reaction is completed, the reaction mixture is placed in a cool, dry place. A furanyl nylon salt solution was obtained, and activated carbon was added to the furanyl nylon salt solution for decolorization. The activated carbon was added in an amount of 1.0% by mass of the furanyl nylon salt solution. After ultrasonic treatment for 10 minutes, the solution was filtered and the activated carbon was separated using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution. Water in the furanyl nylon salt solution was removed by a rotary evaporator. The water bath temperature was controlled at 60° C. during the rotary evaporation process. After water removal, a wet product of furanyl nylon salt was obtained, which was dried by forced air at a drying temperature of 60° C. for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0100] Comparative Example 1

[0101] This comparative example provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0102] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, 3g of pyridine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then passed through to replace the air in the reactor, and the process is repeated three times; then, a circulating heat medium is turned on to heat and heat to 80°C, and stirring is started at the same time, and the speed is 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of nitric acid is added dropwise to the reaction system. % 1,6-hexanediamine aqueous solution, adjust the pH of the reaction system to 7.4, and then continue to react at 80°C for 1 hour; after the isothermal reaction is completed, release the furanyl nylon salt solution, remove water from the furanyl nylon salt solution using a rotary evaporator, and control the water bath temperature at 60°C during the rotary evaporation process. After removing water, a wet product of furanyl nylon salt is obtained, which is dried by blast drying at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0103] Comparative Example 2

[0104] This comparative example provides a furanyl nylon salt, namely, 2,5-furandicarboxylic acid hexamethylenediamine salt.

[0105] The preparation steps of the furanyl nylon salt are as follows: 156g of 2,5-furandicarboxylic acid, 116g of 1,6-hexanediamine, and 269g of deionized water are added to a double-layer glass reactor; nitrogen is then introduced to replace the air in the reactor, and the process is repeated three times; the circulating heat medium is then turned on to heat and heat to 95°C, while stirring is started at a speed of 100r / min to carry out a salt-forming reaction; after the reaction solution is clarified, a 60% by mass concentration of 1,6-hexanediamine aqueous solution is added dropwise to the reaction system, the pH of the reaction system is adjusted to 7.4, and then the reaction is continued at a constant temperature of 80°C for 1h; after the constant temperature reaction is completed, furan is released. The method comprises the following steps: preparing a furanyl nylon salt solution, adding activated carbon to the furanyl nylon salt solution for decolorization, wherein the activated carbon addition amount is 1.0% of the mass of the furanyl nylon salt solution, ultrasonically treating for 15 minutes, filtering, and separating the activated carbon using an aqueous microporous filter membrane with a pore size of 0.22 μm to obtain a clear and transparent furanyl nylon salt solution; removing water from the furanyl nylon salt solution by a rotary evaporator, controlling the water bath temperature at 60°C during the rotary evaporation process, obtaining a furanyl nylon salt wet product after water removal, and drying the product by forced air drying at a drying temperature of 60°C for 6 hours to obtain a furanyl nylon salt 2,5-furandicarboxylic acid hexanediamine salt product.

[0106] The furanyl nylon salt products obtained in the above Examples 1-11 and Comparative Examples 1-2 were analyzed and tested, mainly testing the yield and appearance color of the furanyl nylon salt. The appearance color was tested by a high-precision computer colorimeter.

[0107] The yield is calculated by the following formula:

[0108]

[0109] Where M FDCA Indicates: the mass of monomer 2,5-furandicarboxylic acid;

[0110] M 二胺 Indicates: the mass of monomeric diamine;

[0111] M 尼龙盐 Indicates: the mass of nylon salt obtained after separation and drying.

[0112] The test results of the furanyl nylon salt products obtained in Examples 1-11 and Comparative Examples 1-2 are shown in Table 1 below.

[0113] Table 1

[0114]

[0115]

[0116] The data in Table 1 demonstrate that the furanyl nylon salt prepared using the activated carbon decolorization process in the present invention exhibits excellent overall appearance quality. Both the yield and colorimetric data demonstrate that the preparation method of the present invention exhibits good process stability and a superior product hue.

[0117] In Comparative Example 2, pyridine was not added to the reaction system. The solubility of 2,5-furandicarboxylic acid in water was poor, and the salification reaction temperature had to be increased to dissolve 2,5-furandicarboxylic acid in water. The color value of the obtained nylon salt was significantly reduced.

[0118] In Example 6, the concentration of the reaction system was increased by reducing the amount of deionized water added as a solvent. However, due to the poor solubility of the reactants, the reaction temperature needed to be increased to promote the salt formation reaction, resulting in a poorer color of the resulting reactant. This indicates that the amount of deionized water added has an impact on the salt formation reaction and the quality of the product. Maintaining the salt formation reaction at an appropriate material concentration and a low reaction temperature results in a better product quality.

[0119] In Example 7, the constant temperature reaction time after adjusting the pH value of the reaction system was prolonged, but the yield did not increase significantly.

[0120] Examples 8-11 compared activated carbon decolorization processes, primarily examining the effects of activated carbon dosage and ultrasonic treatment time. The results demonstrated that an appropriate amount of activated carbon and ultrasonic treatment time can efficiently purify furanyl nylon salts. For example, an activated carbon dosage of 1.0% to 1.5% of the mass of the furanyl nylon salt solution and ultrasonic treatment time of 10 to 20 minutes yielded excellent purification results.

[0121] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A method for preparing a furanyl nylon salt, characterized in that: The structural formula of the furanyl nylon salt is shown in formula (I): （I） Wherein, n represents an integer from 2 to 14; The preparation method of the furanyl nylon salt comprises the following steps: (1) mixing 2,5-furandicarboxylic acid, an aliphatic diamine, pyridine and a solvent to obtain a salt-forming reaction material; (2) Under the protection of inert gas, the salt-forming reaction material undergoes a salt-forming reaction at a reaction temperature of 50 to 80° C., and after the reaction liquid becomes clear, the pH value of the reaction system is adjusted to 7.4 to 8.0 with the aliphatic diamine, and the reaction is continued for 1 to 3 hours to obtain a furanyl nylon salt solution; (3) adding activated carbon to the furanyl nylon salt solution for treatment, and then separating the activated carbon to obtain a purified furanyl nylon salt solution; (4) The purified furanyl nylon salt solution is evaporated to remove the solvent, and then dried to obtain a furanyl nylon salt product, wherein the furanyl nylon salt product has a chromaticity L value ≥ 92 and a b value ≤ 3; The amount of pyridine used is 1% to 10% of the mass of the 2,5-furandicarboxylic acid; the solvent is deionized water, and the amount of deionized water used is to control the theoretical mass percentage concentration of the furanyl nylon salt in the salt-forming reaction material to be 40% to 60%.

2. The method for preparing a furanyl nylon salt according to claim 1, wherein The n represents an integer of 2 to 12.

3. The method for preparing the furanyl nylon salt according to claim 1, wherein The aliphatic diamine is selected from any one or more of ethylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,10-decanediamine, and 1,12-dodecanediamine.

4. The method for preparing the furanyl nylon salt according to claim 1, wherein The molar ratio of the 2,5-furandicarboxylic acid and the aliphatic diamine is 1:

1.

5. The method for preparing the furanyl nylon salt according to claim 1, wherein The salt-forming reaction is carried out under stirring at a stirring speed of 80 to 200 r / min.

6. The method for preparing a furanyl nylon salt according to claim 1, wherein: The aliphatic diamine in step (2) is prepared into an aqueous solution and then used to adjust the pH value; the mass percentage concentration of the aliphatic diamine aqueous solution is 50% to 80%.

7. The method for preparing a furanyl nylon salt according to claim 1, wherein: The amount of activated carbon added in step (3) is 1% to 3% of the mass of the furanyl nylon salt solution; and / or, the addition of activated carbon for treatment is ultrasonic treatment of the activated carbon for 10 to 30 minutes; and / or, the separation of activated carbon adopts a microporous membrane filtration method, the pressure is controlled at -0.1Mpa to -0.05Mpa, and the microporous membrane specifications adopt an aqueous phase with a pore size of 0.22 to 1.0μm.

8. The method for preparing a furanyl nylon salt according to claim 1, wherein: The solvent is evaporated in step (4) by using a rotary evaporator, and the water bath temperature is controlled at 50-70°C; and / or, the drying is carried out by forced air drying, the drying temperature is 50-70°C, and the drying time is 4-8h.

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