High-strength high-toughness room-temperature recyclable supramolecular elastomer, applications and preparation method

Abstract

This invention relates to the field of polymer materials technology, specifically to a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, its applications, and preparation methods. This supramolecular elastomer is prepared from prepolymer PU with hyperbranched borate epoxy resin, diamine monomers, and polyetheramine. The hyperbranched borate epoxy resin is prepared using 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxoborane] and other raw materials. This supramolecular elastomer possesses excellent mechanical properties and good recyclability. The preparation process is simple, the reaction conditions are mild, the reaction time is short, and the raw material costs are low, making it suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to high-strength, high-toughness, room-temperature recyclable supramolecular elastomers, their applications, and preparation methods. Background Technology

[0002] In recent years, the intricate structures of organisms in nature have provided a continuous source of inspiration for the design of functional materials. Researchers have developed a series of high-performance polymer materials based on biomimetic structures by simulating biological tissues, such as the fibrous-reinforced structure of animal cartilage or the self-healing properties of organisms. Among them, polyurethane, with its excellent physicochemical properties and designability, shows broad application prospects in cutting-edge fields such as electronic skin, artificial muscles, and flexible wearable devices, and is regarded as one of the most promising recyclable polymer materials.

[0003] However, excellent repair capabilities are of great value for extending the service life of materials and reducing maintenance costs. But in the design of polyurethane materials, there is an inherent contradiction between mechanical properties and recycling efficiency: high strength and high toughness usually depend on "rigid structures" composed of rigid segments or high crosslinking density, while recycling capability requires the molecular chain to have sufficient dynamism, which depends on the dissociation and recombination of reversible bonds. How to endow the material with high mechanical properties while giving it efficient recycling capability, especially self-repairing performance at room temperature, has always been a very challenging core scientific problem in this field.

[0004] To address these challenges, researchers have proposed various molecular design strategies. Existing technologies mainly achieve a balance between the mechanical properties and recyclability of materials by introducing non-covalent interactions or reversible covalent bonds into polymer networks and by constructing covalent-non-covalent hybrid networks.

[0005] Despite significant progress made by the above strategies, most materials still struggle to simultaneously achieve high tensile strength (e.g., exceeding 30 MPa) and high fracture toughness (e.g., exceeding 100 MJ / m). 3 The fact that it requires rapid and efficient recycling at room temperature limits its application in high-end biomimetic fields. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, its application and preparation method.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: This invention provides a hyperbranched borate ester epoxy resin, characterized in that its chemical structural formula is shown in general formula (1), general formula (2) or general formula (3): General formula (1) General formula (2) General formula (3) Where R1 is represented as , or Each Indicates the location where it is connected to R2; R2 is represented as or Each Indicates the position where it is connected to R1 or R3; R3 represents , , or Each Indicates R2 or The connection point is the position where the connection is made.

[0008] The present invention also provides the application of the hyperbranched borate epoxy resin as described above in the preparation of high-strength, high-toughness, room-temperature recyclable supramolecular elastomers.

[0009] This invention also provides a method for preparing the hyperbranched borate ester epoxy resin as described above, using 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxoborane], glycidyl ether monomers, and a photoinitiator, to obtain an epoxy resin containing borate ester bonds through a mercapto-olefin click chemistry reaction, and then sequentially polymerizing it with triol monomers and triglycidyl monomers to obtain the hyperbranched borate ester epoxy resin.

[0010] Furthermore, the conditions for the mercapto-alkene click chemistry reaction are: irradiation under 365 nm ultraviolet light for 30-45 min; and the polymerization reaction temperature is 40℃-60℃, and the time is 1-2 h.

[0011] The present invention also provides a method for preparing a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, wherein a prepolymer PU is mixed with the hyperbranched borate epoxy resin, diamine monomer and polyetheramine as described above and reacted to obtain the supramolecular elastomer.

[0012] Furthermore, the reaction temperature is 40-60℃, and the time is 6-8 h.

[0013] The present invention also provides a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, which is prepared by the method described above.

[0014] The present invention also provides the application of the high-strength, high-toughness, room-temperature recyclable supramolecular elastomer described above in the preparation of biomimetic materials, including electronic skin, artificial muscles, and flexible wearable devices.

[0015] The present invention also provides a method for recycling the high-strength, high-toughness, room-temperature recyclable supramolecular elastomer as described above, wherein the high-strength, high-toughness, room-temperature recyclable supramolecular elastomer is immersed in a degradation solvent and degraded under normal pressure and room temperature conditions to obtain a degradation solution; the degradation solution is then treated at a first recycling temperature and a second recycling temperature respectively to obtain the recycled high-strength, high-toughness, room-temperature recyclable supramolecular elastomer. The degradation solvent is a mixed solvent of an organic phase and an aqueous phase, wherein the organic phase is tetrahydrofuran, N'N-dimethylformamide, methanol or ethanol; The first recovery temperature of the degradation solvent is lower than the temperature of the second degradation condition.

[0016] Furthermore, the first recovery temperature is 40℃-80℃, and the second recovery temperature is 100℃-120℃; the total processing time at the first recovery temperature and the second recovery temperature is 4-8 hours.

[0017] The beneficial effects of this invention are as follows: The high-strength, high-toughness, room-temperature recyclable supramolecular elastomer prepared by this invention possesses excellent mechanical properties, overcoming the challenge of traditional smart composite materials simultaneously exhibiting both high mechanical strength and high flexibility. It achieves the simultaneous enhancement, recycling, and functionalization of the elastomer, providing support for the multifunctional application of biomimetic smart materials. This invention also achieves efficient closed-loop recycling of the high-strength, high-toughness, room-temperature recyclable supramolecular elastomer. Furthermore, the high-performance recyclable supramolecular ionic elastomer prepared by this invention has a simple preparation process, mild reaction conditions, short reaction time, and low raw material cost, making it suitable for industrial production. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the preparation process of the hyperbranched borate epoxy resin and supramolecular elastomer of the present invention. Detailed Implementation

[0019] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] The hyperbranched borate ester epoxy resin of the present invention has the chemical structural formula shown in general formula (1), general formula (2) or general formula (3): General formula (1) General formula (2) General formula (3) Where R1 is represented as , or Each Indicates the location where it is connected to R2; R2 is represented as or Each Indicates the position where it is connected to R1 or R3; R3 represents , , or Each Indicates R2 or The connection point is the position where the connection is made.

[0021] The aforementioned hyperbranched borate epoxy resin can be used to prepare room-temperature recyclable supramolecular elastomers, giving them excellent mechanical properties and good recyclability.

[0022] Specifically, the hyperbranched borate ester epoxy resin (HEBDB) of the present invention uses 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxoborane] (BDB) as the core, and introduces allyl glycidyl ether monomers through chemical reaction to form an epoxy resin (EBDB) containing borate ester bonds. Then, it undergoes a stepwise polymerization reaction with triol monomers and triglycidyl monomers to finally form a hyperbranched borate ester epoxy resin with a highly branched structure.

[0023] HEBDB's molecular structure contains numerous terminal epoxy groups, which can undergo cross-linking reactions with polyurethane prepolymers to form a highly cross-linked three-dimensional network structure, providing the material with excellent mechanical strength and toughness. Simultaneously, the borate ester bonds in HEBDB's molecular structure can dissociate to form 1,4-phenylenediboric acid and hydroxyl compounds, providing the material with good recyclability.

[0024] like Figure 1 As shown, the preparation method of the hyperbranched borate epoxy resin of the present invention includes the following steps: S1. Dissolve 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxoborane] (BDB), glycidyl ether monomers and photoinitiator in the first solvent, irradiate with 365 nm ultraviolet light for 30-45 min and react. After the reaction is completed, concentrate to obtain borate epoxy resin (EBDB).

[0025] Preferably, the glycidyl ether monomer is one of allyl glycidyl ether, polyethylene glycol monoallyl monoglycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, and glycidyl methacrylate.

[0026] Preferably, the photoinitiator is one of 1-hydroxycyclohexylphenyl ketone, 4-dimethylaminopyridine, benzophenone, p-aminoacetone, and 2,2-dimethoxy-2-phenylacetophenone.

[0027] Preferably, the structural formula of the borate ester epoxy resin (EBDB) is as follows: R4 is represented as , , or Each Indicates and The location of the connection.

[0028] Preferably, the mass ratio of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorane] (BDB), glycidyl ether monomer, photoinitiator and first solvent is 1:0.71-1.29:0.03-0.05:10.17-15.25.

[0029] S2. Borate ester epoxy resin EBDB, triol monomers, catalyst, and second solvent are mixed and reacted at 40℃-60℃ for 1-2 h. Triglycidyl monomers are added and reacted at 40℃-60℃ for 1-2 h. The mixture is then concentrated to obtain hyperbranched borate ester epoxy resin HEBDB.

[0030] Preferably, the triol monomer is trimethylolpropane or trimethylolethane.

[0031] Preferably, the catalyst is one of tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, benzyltriethylammonium chloride, and methyltrioctylammonium chloride.

[0032] Preferably, the triglycidyl monomer is one of trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, and triglycidyl isocyanurate.

[0033] Preferably, the mass ratio of borate epoxy resin (EBDB), triol monomer, triglycidyl monomer, catalyst and second solvent is 1:0.09-0.14:0.07-0.10:0.010-0.014:10.10-14.70.

[0034] In the above preparation process, the first solvent and the second solvent are each independently selected from one of acetone, tetrahydrofuran, N,N-dimethylformamide, methanol, and ethanol.

[0035] The present invention discloses a method for preparing a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, which involves mixing and reacting polyether polyol, diisocyanate monomer, and dihydrazide monomer to obtain a prepolymer PU, and then mixing and reacting the prepolymer PU with the above-mentioned hyperbranched borate epoxy resin, diamine monomer, and polyetheramine to obtain a supramolecular elastomer.

[0036] The high-strength, high-toughness, room-temperature recyclable supramolecular elastomer prepared in this invention possesses outstanding mechanical properties, overcoming the challenge of traditional smart composite materials simultaneously exhibiting both high mechanical strength and high flexibility. It achieves the simultaneous enhancement, recycling, and functionalization of the elastomer, providing support for the multifunctional application of biomimetic smart materials. This high-strength, high-toughness, room-temperature recyclable supramolecular elastomer enables efficient closed-loop recycling, and its preparation process is simple, with mild reaction conditions, short reaction time, and low raw material costs, making it suitable for industrial production.

[0037] The reaction temperature for preparing prepolymer PU is 60-80℃ and the reaction time is 0.5-1 h, while the reaction temperature for preparing supramolecular elastomer is 40-60℃ and the reaction time is 6-8 h.

[0038] In the above preparation method, the mass ratio of prepolymer PU, hyperbranched borate epoxy resin (HEBDB), diamine monomer and polyetheramine is 1.93-1.96:0.019-0.029:0.014-0.021:0.12-0.16.

[0039] Preferably, the polyether polyol is one of polytetrahydrofuran, polypropylene glycol, and polyethylene glycol.

[0040] Preferably, the diisocyanate monomer is one of hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(phenyl isocyanate), and toluene diisocyanate.

[0041] Preferably, the dihydrazide monomer is one of isophthalohydrazide, terephthalohydrazide, and adipic dihydrazide.

[0042] Preferably, the diamine monomer is one of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine, 3-dimethylamino-1,2-propanediol, and 3-(diethylamino)-1,2-propanediol.

[0043] Preferably, the polyetheramine is one of polypropylene glycol bis(2-aminopropyl ether) (D230), polypropylene glycol bis(2-aminopropyl ether) (D2000), and O,O'-bis(2-aminopropyl)polyethylene glycol-polypropylene glycol-polyethylene glycol block copolymer (ED-2003).

[0044] The present invention discloses a method for recycling high-strength, high-toughness, room-temperature recyclable supramolecular elastomers. The high-strength, high-toughness, room-temperature recyclable supramolecular elastomers are immersed in a degradation solvent and degraded for 0.5-2 hours under normal pressure and room temperature to obtain a degradation solution. The degradation solution is then treated at a first recycling temperature and a second recycling temperature to complete the recycling process.

[0045] The above-mentioned recycling method is simple, mild, and easy to operate, and the recycled supramolecular elastomer can still maintain good mechanical properties.

[0046] Preferably, normal pressure refers to 0.98 to 1.04 standard atmospheres, and room temperature refers to a temperature of 20℃-30℃.

[0047] Preferably, the degradation solvent is a mixed solvent of an organic phase and an aqueous phase, wherein the organic phase is tetrahydrofuran, N'N-dimethylformamide, methanol or ethanol.

[0048] Preferably, the mass ratio of the organic phase to the aqueous phase in the degradation solvent is 1:10.

[0049] Preferably, the first recovery temperature is 40℃-80℃, and the second recovery temperature is 100℃-120℃; the total treatment time at the first and second recovery temperatures is 4-8 hours; at the first recovery temperature, the solvent in the degradation solution is dried, and at the second recovery temperature, the degradation solution regenerates into an elastomer.

[0050] The effects of the present invention will be illustrated below through specific embodiments and comparative examples.

[0051] Example 1 The preparation process of the hyperbranched borate epoxy resin HEBDB in this embodiment is as follows: (1) 3.10 g of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorane] (BDB), 2.28 g of allyl glycidyl ether and 0.11 g of 1-hydroxycyclohexylphenyl ketone were dissolved in 50 ml of acetone and irradiated with 365 nm ultraviolet light for 30 min. After the reaction was completed, the borate epoxy resin EBDB was obtained by vacuum distillation.

[0052] (2) 3.23 g of EBDB, 0.40 g of trimethylolpropane, 0.043 g of tetrabutylammonium bromide and 44.35 g of tetrahydrofuran were added to a reaction flask and reacted at 40 °C for 1 h. Then, 0.30 g of trimethylolpropane triglycidyl ether was added and reacted at 40 °C for 1 h. The hyperbranched borate epoxy resin HEBDB was obtained by vacuum distillation.

[0053] According to the test results, the HEBDB epoxy value of this embodiment is 0.17 mol / 100g, and Mn=4699 g / mol.

[0054] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this embodiment is as follows: 28.54 g of polytetrahydrofuran, 6.35 g of isophorone diisocyanate, and 2.08 g of isophthalohydrazide were reacted at 80 °C for 0.5 h to obtain prepolymer PU.

[0055] Then, 0.68 g of hyperbranched borate epoxy resin (HEBDB), 0.51 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine and 3.66 g of polypropylene glycol bis(2-aminopropyl ether) were added sequentially to the prepolymer PU, and the reaction was continued at 40°C for 6 h to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0056] The supramolecular elastomer obtained in this embodiment was recycled, and the specific process is as follows: 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of a tetrahydrofuran and water mixture (10:1) and degraded for 0.5 hours at ambient pressure and 25 °C to obtain a degradation solution. Then, a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was obtained under the conditions of 40 °C / 2 h + 100 °C / 2 h. The above recycling process was repeated three times.

[0057] Example 2 The preparation process of the hyperbranched borate epoxy resin HEBDB in this embodiment is as follows: (1) 3.10 g of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorane] (BDB), 2.28 g of allyl glycidyl ether and 0.11 g of 1-hydroxycyclohexylphenyl ketone were dissolved in acetone and irradiated with 365 nm ultraviolet light for 30 min. After the reaction was completed, the borate epoxy resin EBDB was obtained by vacuum distillation.

[0058] (2) 3.23 g of EBDB, 0.40 g of trimethylolpropane, 0.043 g of tetrabutylammonium bromide and 47.4 g of N'N-dimethylformamide were added to a reaction flask and reacted at 40 °C for 1 h. Then, 0.30 g of trimethylolpropane triglycidyl ether was added and reacted at 40 °C for 1 h. The hyperbranched borate epoxy resin HEBDB was obtained by vacuum distillation.

[0059] According to the test results, the HEBDB epoxy value of this embodiment is 0.15 mol / 100g, and Mn=6579 g / mol.

[0060] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this embodiment is as follows: 20.89 g of polytetrahydrofuran, 4.64 g of isophorone diisocyanate, and 1.52 g of isophthalyl hydrazide were reacted at 80 °C for 0.5 h to obtain prepolymer PU. Then, 0.40 g of hyperbranched borate epoxy resin (HEBDB), 0.30 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine, and 3.18 g of polypropylene glycol bis(2-aminopropyl ether) were added sequentially to the prepolymer PU, and the reaction was continued at 40 °C for 6 h to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0061] The supramolecular elastomer obtained in this embodiment was recycled, and the specific process is as follows: 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of a tetrahydrofuran and water mixture (10:1) and degraded for 0.5 hours at ambient pressure and 25°C to obtain a degradation solution. Then, a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was obtained under the conditions of 40°C / 2h + 100°C / 2h. The above recycling process was repeated three times.

[0062] Example 3 The preparation process of the hyperbranched borate epoxy resin HEBDB in this embodiment is as follows: (1) 3.10 g of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorane] (BDB), 2.28 g of allyl glycidyl ether and 0.11 g of 1-hydroxycyclohexylphenyl ketone were dissolved in acetone and irradiated with 365 nm ultraviolet light for 30 min. After the reaction was completed, the borate epoxy resin EBDB was obtained by vacuum distillation.

[0063] (2) 3.23 g of EBDB, 0.40 g of trimethylolpropane, 0.043 g of tetrabutylammonium bromide and 39.45 g of ethanol were added to a reaction flask and reacted at 40 °C for 1 h. Then, 0.30 g of trimethylolpropane triglycidyl ether was added and reacted at 40 °C for 1 h. The hyperbranched borate epoxy resin HEBDB was obtained by vacuum distillation.

[0064] According to the test results, the HEBDB epoxy value of this embodiment is 0.12 mol / 100g, and Mn=9675g / mol.

[0065] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this embodiment is as follows: 36.51 g of polytetrahydrofuran, 8.11 g of isophorone diisocyanate, and 2.66 g of isophthalyl hydrazide were reacted at 80 °C for 0.5 h to obtain prepolymer PU. Then, 0.97 g of hyperbranched borate epoxy resin (HEBDB), 0.72 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine, and 4.16 g of polypropylene glycol bis(2-aminopropyl ether) were added sequentially to the prepolymer PU, and the reaction was continued at 40 °C for 6 h to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0066] The supramolecular elastomer obtained in this embodiment was recycled, and the specific process is as follows: 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of a tetrahydrofuran and water mixture (10:1) and degraded for 0.5 hours at ambient pressure and 25°C to obtain a degradation solution. Then, a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was obtained under the conditions of 40°C / 2h + 100°C / 2h. The above recycling process was repeated three times.

[0067] Example 4 The preparation process of the hyperbranched borate epoxy resin HEBDB in this embodiment is as follows: (1) 3.10 g of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorbacon] (BDB), 3.16 g of polyethylene glycol monoallyl monoglycidyl ether and 0.12 g of 1-hydroxycyclohexylphenyl ketone were dissolved in acetone and irradiated with 365 nm ultraviolet light for 30 min. After the reaction was completed, the borate epoxy resin EBDB was obtained by vacuum distillation.

[0068] (2) 3.76 g of EBDB, 0.40 g of trimethylolpropane, 0.045 g of tetrabutylammonium bromide and 44.35 g of tetrahydrofuran were added to a reaction flask and reacted at 40 °C for 1 h. Then, 0.30 g of trimethylolpropane triglycidyl ether was added and reacted at 40 °C for 1 h. The hyperbranched borate epoxy resin HEBDB was obtained by vacuum distillation.

[0069] According to the test results, the HEBDB epoxy value of this embodiment is 0.14 mol / 100g, and Mn=5784g / mol.

[0070] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this embodiment is as follows: 25.27 g of polytetrahydrofuran, 5.61 g of isophorone diisocyanate, and 1.84 g of isophthalohydrazide were reacted at 80 °C for 0.5 h to obtain prepolymer PU. Then, 0.68 g of hyperbranched borate epoxy resin (HEBDB), 0.42 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine, and 3.45 g of polypropylene glycol bis(2-aminopropyl ether) (D2000) were added sequentially to the prepolymer PU, and the reaction was continued at 40 °C for 6 h to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0071] The supramolecular elastomer obtained in this embodiment was recycled, and the specific process is as follows: 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of a tetrahydrofuran and water mixture (10:1) and degraded for 0.5 hours at ambient pressure and 25°C to obtain a degradation solution. Then, a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was obtained under the conditions of 40°C / 2h + 100°C / 2h. The above recycling process was repeated three times.

[0072] Example 5 The preparation process of the hyperbranched borate epoxy resin HEBDB in this embodiment is as follows: (1) 3.10 g of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorbacon] (BDB), 4.00 g of 4-hydroxybutylacrylate glycidyl ether and 0.14 g of 1-hydroxycyclohexylphenyl ketone were dissolved in acetone and irradiated with 365 nm ultraviolet light for 30 min. After the reaction was completed, the borate epoxy resin EBDB was obtained by vacuum distillation.

[0073] (2) 4.26 g EBDB, 0.40 g trimethylolpropane, 0.050 g tetrabutylammonium bromide and 44.35 g tetrahydrofuran were added to a reaction flask and reacted at 40 °C for 1 h. Then, 0.30 g trimethylolpropane triglycidyl ether was added and reacted at 40 °C for 1 h. The hyperbranched borate epoxy resin HEBDB was obtained by vacuum distillation.

[0074] According to the test results, the HEBDB epoxy value of this embodiment is 0.13 mol / 100g, and Mn=6343g / mol.

[0075] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this embodiment is as follows: 24.18 g of polytetrahydrofuran, 5.37 g of isophorone diisocyanate, and 1.73 g of isophthalyl hydrazide were reacted at 80 °C for 0.5 h to obtain prepolymer PU. Then, 0.68 g of hyperbranched borate epoxy resin (HEBDB), 0.39 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine, and 3.39 g of polypropylene glycol bis(2-aminopropyl ether) were added sequentially to the prepolymer PU, and the reaction was continued at 40 °C for 6 h to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0076] The supramolecular elastomer obtained in this embodiment was recycled, and the specific process is as follows: 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of a tetrahydrofuran and water mixture (10:1) and degraded for 0.5 hours at ambient pressure and 25°C to obtain a degradation solution. Then, a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was obtained under the conditions of 40°C / 2h + 100°C / 2h. The above recycling process was repeated three times.

[0077] Example 6 The preparation process of the hyperbranched borate epoxy resin HEBDB in this embodiment is as follows: (1) 3.10 g of 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxorane] (BDB), 2.8 g of glycidyl methacrylate and 0.12 g of 1-hydroxycyclohexylphenyl ketone were dissolved in acetone and irradiated with 365 nm ultraviolet light for 30 min. After the reaction was completed, the borate epoxy resin EBDB was obtained by vacuum distillation.

[0078] (2) 3.56 g of EBDB, 0.40 g of trimethylolpropane, 0.042 g of tetrabutylammonium bromide and 44.35 g of tetrahydrofuran were added to a reaction flask and reacted at 40 °C for 1 h. Then, 0.30 g of trimethylolpropane triglycidyl ether was added and reacted at 40 °C for 1 h. The hyperbranched borate epoxy resin HEBDB was obtained by vacuum distillation.

[0079] According to the test, the HEBDB epoxy value of this embodiment is 0.16 mol / 100g, and Mn=5104g / mol.

[0080] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this embodiment is as follows: 27.45 g of polytetrahydrofuran, 6.10 g of isophorone diisocyanate, and 2.00 g of isophthalyl hydrazide were reacted at 80 °C for 0.5 h to obtain prepolymer PU. Then, 0.68 g of hyperbranched borate epoxy resin (HEBDB), 0.48 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine, and 3.59 g of polypropylene glycol bis(2-aminopropyl ether) were added sequentially to the prepolymer PU, and the reaction was continued at 40 °C for 6 h to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0081] The supramolecular elastomer obtained in this embodiment was recycled, and the specific process is as follows: 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of a tetrahydrofuran and water mixture (10:1) and degraded for 0.5 hours at ambient pressure and 25°C to obtain a degradation solution. Then, a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was obtained under the conditions of 40°C / 2h + 100°C / 2h. The above recycling process was repeated three times.

[0082] Comparative Example The elastomer prepared in this comparative example is prepared using the following specific process: 10 g of polytetrahydrofuran, 2.22 g of isophorone diisocyanate, and 0.73 g of isophthalyl hydrazide were mixed and reacted at 80 °C for 0.5 h to obtain prepolymer PU. The prepolymer PU was then mixed with 0.27 g of N,N-dimethyl-N',N'-di(2-hydroxypropyl)-1,3-propanediamine and reacted at 40 °C for another 6 h to obtain the elastomer.

[0083] The elastomer was recycled in the same manner as in Example 1.

[0084] The mechanical properties of the supramolecular elastomers prepared in the above embodiments and the elastomers in the comparative examples are shown in Table 1, and the mechanical properties before and after recycling are shown in Table 2.

[0085] Table 1. Comparison of mechanical properties of supramolecular elastomers in Examples 1-6 and elastomers in comparative examples. Table 2 Comparison of mechanical properties of supramolecular elastomers in Examples 1-6 and elastomers in comparative examples before and after recycling. The test results above show that the comparative polyurethane elastomer has poor mechanical properties, and its performance drops significantly after three recycling cycles. This indicates that the elastomer prepared without the HEBDB of this invention has certain mechanical properties but poor recyclability.

[0086] In Example 1, after introducing HEBDB of the present invention, the tensile strength, elongation at break and fracture toughness of its supramolecular elastomer were significantly improved, and the performance was almost undamaged after three recyclings, proving that the hyperbranched structure successfully solved the contradiction between mechanical properties and recycling efficiency.

[0087] Example 2 achieved optimal mechanical properties by adjusting the formula ratio, and was the sample with the best overall performance among all examples.

[0088] In Example 3, after increasing the molecular weight of the hyperbranched borate epoxy resin, the mechanical properties remained good, and the recycling performance was also excellent, indicating that molecular weight has a certain influence on mechanical properties, but recycling stability is not affected by changes in molecular weight.

[0089] Examples 4-6 use polyethylene glycol monoallyl monoglycidyl ether, 4-hydroxybutyl acrylate glycidyl ether, and glycidyl methacrylate to prepare hyperbranched borate epoxy resins, respectively. The resulting supramolecular elastomers still maintain excellent mechanical properties and recyclability.

[0090] In summary, this invention introduces hyperbranched borate ester epoxy resin to construct a novel dynamic network structure, successfully overcoming the bottleneck of the traditional incompatibility between mechanical properties and recycling efficiency in elastomer materials.

[0091] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hyperbranched borate ester epoxy resin, characterized in that, Its chemical structural formula is shown in general formula (1), general formula (2) or general formula (3): General formula (1) General formula (2) General formula (3) Where R1 is represented as , or Each Indicates the location where it is connected to R2; R2 is represented as or Each Indicates the position where it is connected to R1 or R3; R3 represents , , or Each Indicates R2 or The connection point is the position where the connection is made.

2. The application of the hyperbranched borate epoxy resin as described in claim 1 in the preparation of high-strength, high-toughness, room-temperature recyclable supramolecular elastomers.

3. A method for preparing the hyperbranched borate ester epoxy resin as described in claim 1, characterized in that, Using 2,2-(1,4-phenylene)-bis[4-mercapto-1,3,2-dioxoborane], glycidyl ether monomers, and a photoinitiator, an epoxy resin containing borate ester bonds is obtained through a mercapto-olefin click chemistry reaction. Then, it is polymerized sequentially with triol monomers and triglycidyl monomers to obtain the hyperbranched borate ester epoxy resin.

4. The method for preparing a hyperbranched borate ester epoxy resin according to claim 3, characterized in that, The conditions for the thiol-olefin click chemistry reaction are: irradiation under 365 nm ultraviolet light for 30-45 min; and the polymerization reaction temperature is 40℃-60℃, and the time is 1-2 h.

5. A method for preparing a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, characterized in that, The supramolecular elastomer is obtained by mixing and reacting the prepolymer PU with the hyperbranched borate epoxy resin, diamine monomer, and polyetheramine as described in claim 1.

6. The method for preparing a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer according to claim 5, characterized in that, The reaction temperature is 40-60℃ and the reaction time is 6-8 h.

7. A high-strength, high-toughness, room-temperature recyclable supramolecular elastomer, characterized in that, It is prepared by the method described in claim 5 or 6.

8. The application of the high-strength, high-toughness, room-temperature recyclable supramolecular elastomer as described in claim 7 in the preparation of biomimetic materials, characterized in that, The biomimetic materials include electronic skin, artificial muscles, and flexible wearable devices.

9. A method for degrading and recycling the high-strength, high-toughness, room-temperature recyclable supramolecular elastomer as described in claim 7, characterized in that, The high-strength, high-toughness, room-temperature recyclable supramolecular elastomer was immersed in a degradation solvent and degraded under normal pressure and room temperature conditions; the degradation solution was then treated at a first recovery temperature and a second recovery temperature respectively to complete the recovery. The degradation solvent is a mixed solvent of an organic phase and an aqueous phase, wherein the organic phase is tetrahydrofuran, N'N-dimethylformamide, methanol or ethanol; The first recovery temperature is lower than the second recovery temperature.

10. The method for recycling a high-strength, high-toughness, room-temperature recyclable supramolecular elastomer according to claim 9, characterized in that, The first recovery temperature is 40℃-80℃, and the second recovery temperature is 100℃-120℃; the total processing time at the first recovery temperature and the second recovery temperature is 4-8 hours.

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