Carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid, preparation method and application thereof

Abstract

The present invention discloses a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid, a preparation method and an application thereof. The preparation method comprises: reacting a uniformly mixed reaction system comprising a trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate, and a solvent to prepare a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid. The preparation method provided by the present invention uses furandicarboxylic acid, which has a wide range of biological sources, as a raw material, and has the dual advantages of saving resources and protecting the environment. The preparation method is simple, has few side reactions, and is simple to post-process. The series of carboxyl-terminated hyperbranched polyamides prepared by the present invention can be used as a curing agent for epoxy resins. The epoxy resin material using the carboxyl-terminated hyperbranched polyamide as a curing agent has a carboxyl-terminated structure in its structure, which enables the material to have good degradation performance under alkaline conditions.

Description

Technical Field

[0001] The present invention relates to a polyamide material, in particular to a carboxyl-terminated hyperbranched polyamide material based on furandicarboxylic acid, and a preparation method and application thereof, belonging to the technical field of bio-based hyperbranched polyamide synthesis. Background Art

[0002] Compared to linear polymers, hyperbranched polymers possess unique structures and properties. After two decades of research, hyperbranched polymers have rapidly become an important class of polymer materials with broad application potential due to their unique structural and performance characteristics, as well as their scalable production capabilities. Because hyperbranched polymers do not require a perfect structure, reactions do not require multiple steps of synthesis and purification; the desired polymer can be synthesized from monomers in a single step, significantly reducing synthesis costs. Furthermore, the presence of a large number of functional groups allows for modification to yield polymers with diverse properties and special applications, demonstrating enormous application value in a wide range of fields, from coatings, adhesives, and rheological additives to supramolecular chemistry, nanotechnology, biomaterials, optoelectronic materials, and drug delivery.

[0003] Currently, the technology for synthesizing hyperbranched polyamides in one step has been developed and is often used in material modification and engineering. However, the raw materials for hyperbranched polyamides are mostly petroleum-based raw materials, such as adipic acid and melamine, which are detrimental to resources and the environment. Summary of the Invention

[0004] The main purpose of the present invention is to provide a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid and a preparation method thereof, so as to overcome the deficiencies of the prior art.

[0005] Another object of the present invention is to provide applications of the carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid.

[0006] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0007] An embodiment of the present invention provides a method for preparing a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid, which comprises reacting a uniformly mixed reaction system comprising a trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate, and a solvent to prepare the carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid.

[0008] In some embodiments, the trifunctional amine compound has a structural formula as shown in formula (I):

[0009]

[0010] Wherein, R includes any one of the following structures:

[0011]

[0012] Wherein, * is the point of attachment of the group.

[0013] The embodiment of the present invention also provides a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid prepared by the above preparation method.

[0014] The embodiments of the present invention also provide the application of the aforementioned furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide in the field of epoxy resin curing.

[0015] An embodiment of the present invention further provides an epoxy resin curing agent, which includes the aforementioned furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide.

[0016] Correspondingly, an embodiment of the present invention further provides a hyperbranched polyamide-cured epoxy resin material, which is prepared by a curing reaction of the epoxy resin curing agent and bisphenol A epoxy resin.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The preparation method provided by the present invention uses furandicarboxylic acid, which has a wide range of biological sources, as a raw material, which can not only reduce the dependence of the epoxy resin industry on petrochemical products, but also reduce environmental pollution during its production process and inhibit the generation of environmental pollutants, thus having the dual advantages of saving resources and protecting the environment. The preparation method is simple, has few side reactions, and is easy to post-process. Moreover, by regulating the ratio of the raw acid to the amine, a hyperbranched polyamide with a carboxyl-terminated structure can be obtained in one step without the need for a second end group modification.

[0019] 2) The carboxyl-terminated hyperbranched polyamide prepared by the present invention can be used as a curing agent for epoxy resin. The epoxy resin material using the carboxyl-terminated hyperbranched polyamide as a curing agent has a carboxyl-terminated structure in its structure, which enables the material to have good degradation performance under alkaline conditions. DETAILED DESCRIPTION

[0020] In view of the defects of the existing technology, the inventors of this case have proposed the technical solution of the present invention after long-term research and extensive practice. The present invention uses furandicarboxylic acid, which has a wide range of biological sources, as raw material, has a simple synthesis process, and the prepared carboxyl-terminated highly branched polyamide can be used for the curing of epoxy resins. The blocked carboxyl groups in its structure can give the material good alkaline degradation properties, enabling the recycling and reuse of the material.

[0021] The technical solution of the present invention will be described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] Specifically, as one aspect of the technical solution of the present invention, a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid is prepared from the following components: a trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate, and a solvent.

[0023] In some embodiments, the furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide is prepared from the following components in the following parts by mass: 5-10 parts of a trifunctional amine compound, 15-30 parts of furandicarboxylic acid, 1-5 parts of pyridine, 5-65 parts of triphenyl phosphite and / or triphenyl phosphate, and 100-400 parts of a solvent.

[0024] In some embodiments, the trifunctional amine compound has a structural formula as shown in formula (I):

[0025]

[0026] Wherein, R includes any one of the following structures:

[0027]

[0028] Wherein, * is the point of attachment of the group.

[0029] In some more specific embodiments, the trifunctional amine compound may include any one or a combination of two or more of tris(2-aminoethyl)amine, tris(3-aminopropyl)amine, 1,3,5-triaminobenzene, 1,3,5-triaminocyclohexane, 1,2,4-triaminobenzene, 2,4,5-triaminopyridine, 2,4,6-triaminopyrimidine, 1,5,9-triaminotriphenylene, 2,6,14-triaminotriptylide, 2,7,14-triaminotriptylide, 4-aminophenol phosphate thiosulfate, 4,4′,4″-triaminotriphenylmethane, 5-nitroso-2,4,6-triaminopyrimidine, 2,4,5-triamino-3-fluorobenzoic acid methyl ester, etc., but is not limited thereto.

[0030] In some embodiments, the furandicarboxylic acid may include 2,5-furandicarboxylic acid, but is not limited thereto.

[0031] Further, the solvent may include N-methylpyrrolidone, but is not limited thereto.

[0032] Another aspect of the present invention provides a method for preparing a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid, comprising:

[0033] A uniformly mixed reaction system comprising a trifunctional amine compound, furandicarboxylic acid, pyridine (as a catalyst), triphenyl phosphite and / or triphenyl phosphate (as a catalyst), and a solvent is reacted to produce a furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide. The present invention utilizes two catalysts: triphenyl phosphite (phosphite lipid compound) and / or triphenyl phosphate, which exhibit a favorable chain extension reaction for polyamide resins; and pyridine, which effectively promotes hydrolysis and deacidifies the catalyst due to its alkalinity. Thus, the two catalysts exhibit a mutually promoting and synergistic effect.

[0034] In some more specific embodiments, the preparation method specifically includes: mixing a trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate, and a solvent to form a corresponding uniform mixed reaction system, and first reacting at 10-30°C for 2-3 hours to allow the reactants to be fully dissolved in the solvent and fully contact each other to facilitate the subsequent reaction; then heating to 70-90°C for 3-4 hours to carry out a condensation reaction between the acid and the amine; finally heating to 120-140°C and continuing to stir and react for 6-8 hours to obtain a hyperbranched polyamide structure, ensuring that the reaction is complete, and finally obtaining the corresponding carboxyl-terminated hyperbranched polyamide.

[0035] Furthermore, the preparation method further comprises: after the reaction is completed, washing, filtering and drying the obtained mixture.

[0036] In some embodiments, the mass fractions of the trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate and solvent are 5-10:15-30:1-5:5-65:100-400. That is, from another perspective, the mass fractions of the various raw materials are 5-10 parts of the trifunctional amine compound, 15-30 parts of furandicarboxylic acid, 1-5 parts of pyridine, 5-65 parts of triphenyl phosphite, and 100-400 parts of the solvent.

[0037] In some embodiments, the trifunctional amine compound has a structural formula as shown in formula (I):

[0038]

[0039] Wherein, R includes any one of the following structures:

[0040]

[0041] In some more specific embodiments, the trifunctional amine compound may include tris(2-aminoethyl)amine Tris (3-aminopropyl)amine 1,3,5-Triaminobenzene 1,3,5-Triaminocyclohexane 1,2,4-Triaminobenzene 2,4,5-triaminopyridine 2,4,6-triaminopyrimidine 1,5,9-Triaminotriphenylene 2,6,14-Triaminotriptycene 2,7,14-Triaminotriptycene 4-Aminophenol thiophosphate 4,4',4"-Triaminotriphenylmethane 5-Nitroso-2,4,6-triaminopyrimidine 2,4,5-Triamino-3-fluorobenzoic acid methyl ester etc. or a combination of two or more thereof, but not limited thereto.

[0042] The furandicarboxylic acid and solvent used in the preparation method of the present invention are the same as those described above. The preparation method provided by the present invention uses furandicarboxylic acid, which has a wide range of biological sources, as a raw material, which can reduce the epoxy resin industry's dependence on petrochemical products and also reduce environmental pollution during the production process, thus having the dual advantages of saving resources and protecting the environment.

[0043] In some more specific embodiments, the method for preparing the carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid comprises:

[0044] A trifunctional amine, 2,5-furandicarboxylic acid, pyridine, and N-methylpyrrolidone are mixed, nitrogen is introduced, and the mixture is stirred at room temperature until homogeneous. Triphenyl phosphite and / or triphenyl phosphate are then added. The mixture is reacted at 10-30°C for 2-3 hours, then heated to 70-90°C for 3-4 hours, and finally heated to 120-140°C with continued stirring for 6-8 hours. The mixture is washed with distilled water, filtered, and dried to obtain a carboxyl-terminated hyperbranched polyamide.

[0045] As one of the preferred solutions, the molar ratio of the trifunctional amine compound to furandicarboxylic acid is 1:2.5 to 1:3. The preferred molar ratio can increase the carboxyl end-capping rate of the product.

[0046] As one of the preferred solutions, the molar ratio of the amine to the acid group (including any acid functional group of anhydride group) is 0.3 to 3, preferably 0.5 to 0.6.

[0047] As one of the preferred solutions, the reaction time is about 14 h to 16 h. If the reaction time is too short, the reaction will be incomplete.

[0048] The reaction mechanism and reaction formula for preparing carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid according to the present invention are as follows:

[0049]

[0050] Another aspect of the embodiments of the present invention further provides a furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide prepared by any of the aforementioned preparation methods.

[0051] Correspondingly, another aspect of the embodiments of the present invention further provides the use of the aforementioned furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide in the field of epoxy resin curing, such as as a curing agent for epoxy resin (especially bisphenol A epoxy resin).

[0052] Furthermore, another aspect of the embodiments of the present invention provides an epoxy resin curing agent, which includes the aforementioned carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid.

[0053] Another aspect of the embodiments of the present invention further provides an epoxy resin material using the furandicarboxylic acid-based carboxyl-terminated hyperbranched polyamide prepared by the aforementioned method as a curing agent.

[0054] Specifically, the hyperbranched polyamide-cured epoxy resin material is prepared by curing the aforementioned epoxy resin curing agent (ie, carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid) and bisphenol A epoxy resin.

[0055] Furthermore, the preparation method of the hyperbranched polyamide-cured epoxy resin material specifically includes curing a mixture of the carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid and bisphenol A epoxy resin by gradually heating the mixture from 90°C to 120°C for 2 hours, and then curing the mixture at 130°C, 150°C, and 180°C for 2 hours, respectively. The resulting epoxy resin material can achieve a tensile strength of 90 MPa, comparable to petroleum-based commercial epoxy resins.

[0056] Furthermore, the hyperbranched polyamide-cured epoxy resin material has a carboxyl-terminated structure, and the carboxyl-terminated structure in the structure enables the material to be well degraded under alkaline conditions.

[0057] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments. This embodiment is implemented on the premise of the technical solution of the invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0058] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0059] Example 1

[0060] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, tris(2-aminoethyl)amine (0.5118 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.6389 g, 10.5 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0061] Example 2

[0062] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, tris(2-aminopropyl)amine (0.511 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0063] Example 3

[0064] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, tris(2-aminopropyl)amine (0.511 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 3 h, and finally to 130°C with continued stirring for 6 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0065] Example 4

[0066] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, tris(3-aminopropyl)amine (0.6591 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.6389 g, 10.5 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0067] Example 5

[0068] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, tris(3-aminopropyl)amine (0.6591 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0069] Example 6

[0070] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, tris(3-aminopropyl)amine (0.6591 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 3 h, and finally to 130°C with continued stirring for 6 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0071] Example 7

[0072] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, 1,3,5-triaminobenzene (0.4311 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.6389 g, 10.5 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL) were added. Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0073] Example 8

[0074] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,3,5-triaminobenzene (0.4311 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0075] Example 9

[0076] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,3,5-triaminobenzene (0.4311 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 3 h, and finally to 130°C with continued stirring for 6 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0077] Example 10

[0078] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,3,5-triaminocyclohexane (0.4522 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.6389 g, 10.5 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0079] Example 11

[0080] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,3,5-triaminocyclohexane (0.4522 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a pale yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a pale yellow solid powder.

[0081] Example 12

[0082] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,3,5-triaminocyclohexane (0.4522 g, 3.5 mmol), 1,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 3 h, and finally to 130°C with continued stirring for 6 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0083] Example 13

[0084] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,2,4-triaminobenzene (0.6860 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.6389 g, 10.5 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0085] Example 14

[0086] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,2,4-triaminobenzene (0.6860 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 4 h, and finally to 130°C with continued stirring for 8 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried in vacuo to obtain a light yellow solid powder.

[0087] Example 15

[0088] To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet, add 1,2,4-triaminobenzene (0.6860 g, 3.5 mmol), 2,5-furandicarboxylic acid (1.3658 g, 8.75 mmol), N-methylpyrrolidone (40 mL), and pyridine (5 mL). Nitrogen was introduced and the mixture was stirred at room temperature until completely dissolved. Triphenyl phosphite (5 mL, 6.5582 g) was then added. The mixture was reacted at 20°C for 2 h, then heated to 70°C for 3 h, and finally to 130°C with continued stirring for 6 h. After the reaction ceased, the reaction solution was precipitated in water, filtered, washed, and dried to obtain a light yellow solid powder. The crude product was reprecipitated in acetone and dried under vacuum to obtain a light yellow solid powder.

[0089] Example 16

[0090] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 2,4,5-triaminopyridine, the reaction is carried out at 10°C for 3 hours, then the temperature is raised to 70°C for 4 hours, and finally the temperature is raised to 120°C, stirring is continued, and the reaction is carried out for 8 hours.

[0091] Example 17

[0092] The only difference between this example and Example 1 is that tris(2-aminoethyl)amine is replaced by 2,4,6-triaminopyrimidine, the reaction is carried out at 30°C for 2 hours, then the temperature is raised to 80°C for 4 hours, and finally the temperature is raised to 130°C, stirring is continued, and the reaction is carried out for 8 hours.

[0093] Example 18

[0094] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 1,5,9-triaminotriphenylene, the reaction is carried out at 30°C for 2 hours, then the temperature is raised to 90°C for 3 hours, and finally the temperature is raised to 140°C, stirring is continued, and the reaction is carried out for 6 hours.

[0095] Example 19

[0096] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 2,6,14-triaminotriptycene, the reaction is carried out at 30° C. for 3 h, then the temperature is raised to 80° C. for 4 h, and finally the temperature is raised to 130° C., and the reaction is continued with stirring for 7 h.

[0097] Example 20

[0098] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 2,7,14-triaminotriptycene, and triphenyl phosphite is replaced by triphenyl phosphate.

[0099] Example 21

[0100] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 4-aminophenol phosphothioate.

[0101] Example 22

[0102] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 4,4′,4″-triaminotriphenylmethane.

[0103] Example 23

[0104] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 5-nitroso-2,4,6-triaminopyrimidine.

[0105] Example 24

[0106] The only difference between this embodiment and embodiment 1 is that tris(2-aminoethyl)amine is replaced by 2,4,5-triamino-3-fluorobenzoic acid methyl ester.

[0107] Application Example 1

[0108] The carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid obtained in the above examples was used as a curing agent and mixed with bisphenol A epoxy resin. The mixture was gradually heated from 90°C to 120°C and cured for 2 hours. The mixture was then cured at 130°C, 150°C, and 180°C for 2 hours. The resulting epoxy resin material (using Example 1 as an example) exhibited a tensile strength of 90 MPa, an elongation at break of 8%, and a tensile modulus of 3700 MPa, comparable to commercial petroleum-based epoxy resins. It also exhibited good degradation resistance under alkaline conditions.

[0109] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments using other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0110] Comparative Example 1

[0111] This comparative example differs from Example 1 in that 2,5-furandicarboxylic acid is replaced with terephthalic acid (the benzene ring structure provides rigidity), resulting in a hyperbranched polyamide. This was used as a curing agent in epoxy curing with bisphenol A. The resulting epoxy resin material exhibited a tensile strength of 77 MPa, an elongation at break of 10%, and a tensile modulus of 3100 MPa.

[0112] Comparative Example 2

[0113] Compared with Example 1, the difference between this comparative example and Example 1 is that: the molecular weight of the polyamide material finally obtained is reduced due to the lack of pyridine addition, and the mechanical properties of the epoxy resin material after curing are also reduced.

[0114] Comparative Example 3

[0115] This comparative example differs from Example 1 in that no triphenyl phosphite and / or triphenyl phosphate is added. The molecular weight of the polyamide material obtained is reduced, and the mechanical properties of the cured epoxy resin material are also reduced.

[0116] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical variations made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid, characterized in that: include: A trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate, and a solvent are mixed to form a uniform mixed reaction system, and the mixture is first reacted at 10-30° C. for 2-3 hours, then heated to 70-90° C. for 3-4 hours, and finally heated to 120-140° C. with continued stirring for 6-8 hours to prepare a carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid; The mass ratio of the trifunctional amine compound, furandicarboxylic acid, pyridine, triphenyl phosphite and / or triphenyl phosphate to the solvent is 5-10:15-30:1-5:5-65:100-400; and the molar ratio of the trifunctional amine compound to furandicarboxylic acid is 1:2.5-1:3; The structural formula of the trifunctional amine compound is shown in formula (I): Wherein, R is selected from any one of the following structures: Wherein, * is the point of attachment of the group.

2. The preparation method according to claim 1, wherein: The trifunctional amine compound is selected from any one or a combination of two or more of tris(2-aminoethyl)amine, tris(3-aminopropyl)amine, 1,3,5-triaminobenzene, 1,3,5-triaminocyclohexane, 1,2,4-triaminobenzene, 2,4,5-triaminopyridine, 2,4,6-triaminopyrimidine, 1,5,9-triaminotriphenylene, 2,6,14-triaminotriptylide, 2,7,14-triaminotriptylide, 4-aminophenol phosphate thiosulfate, 4,4',4"-triaminotriphenylmethane, 5-nitroso-2,4,6-triaminopyrimidine, and 2,4,5-triamino-3-fluorobenzoic acid methyl ester.

3. The preparation method according to claim 1, wherein: The furandicarboxylic acid is 2,5-furandicarboxylic acid.

4. The preparation method according to claim 1, wherein: The solvent is N-methylpyrrolidone.

5. A carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid according to claim 5 in the field of epoxy resin curing.

7. An epoxy resin curing agent, characterized in that The method comprises the carboxyl-terminated hyperbranched polyamide based on furandicarboxylic acid as claimed in claim 5.

8. A hyperbranched polyamide-cured epoxy resin material, characterized in that: The epoxy resin material is prepared by curing reaction of the epoxy resin curing agent according to claim 7 and bisphenol A epoxy resin.

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