Recyclable high-performance bionic supramolecular elastomer and preparation method thereof

Abstract

The invention relates to the technical field of high polymer materials, in particular to a recyclable high-performance bionic supramolecular elastomer and a preparation method thereof. The preparation method comprises the following steps: swelling a second network monomer solution in a first cross-linked network and then cross-linking to obtain the recoverable high-performance bionic supramolecular elastomer, the first cross-linked network is prepared from vinyl ionic liquid, polyethylene glycol diacrylate and a photoinitiator through a click reaction; the second network monomer solution is obtained by mixing lipoic acid, an imidazole ionic liquid, a catechol functionalized hyperbranched polymer and a solvent. The elastomer is excellent in mechanical property, and random adjustment between a mechanical high-strength state and a mechanical high-flexibility state is achieved; efficient closed-loop recycling can be achieved, the mechanical property retention rate of the material after three times of recycling is 100%, and guarantee is provided for multifunctional application of the bionic intelligent material.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and more specifically, to a recyclable high-performance bionic supramolecular elastomer and a preparation method thereof. Background Art

[0002] In recent years, wearable electronic devices have developed rapidly in the fields of personal health monitoring, human-machine interfaces, energy harvesting, and flexible displays. Currently, the research on stretchable electronic devices mainly focuses on stretchable conductors. As the most important component in stretchable electronic devices, it combines elasticity and conductivity ingeniously. Elastomers have intrinsic stretchability, showing great deformation ability and the advantages of being easy to prepare and process.

[0003] However, when elastomers are applied to stretchable electronic devices, there are problems such as poor tear resistance. In order to obtain practical mechanical properties and elasticity, elastomers need to be enhanced through nano-filling or chemical cross-linking. However, nano-filling has problems such as filler aggregation, difficult interface regulation, and high processing viscosity. On the other hand, covalently cross-linked elastomers are difficult to reprocess and reuse, making elastomer products one of the main challenges faced by solid waste management and circular economy.

[0004] In contrast, organisms have evolved various organizational structures to adapt to the challenges of the natural environment. Due to their unique structural configurations, they endow themselves with extraordinary mechanical properties beyond their material composition, providing inspiration for the mechanical toughening regulation and modification of traditional engineering materials. In recent years, there have been a large number of research reports on bionic intelligent materials in the fields of intelligent drive, flexible sensing, etc. However, most current bionic intelligent materials and devices have problems such as non-adjustable mechanical properties, and it is difficult for their structures and functions to self-heal after being damaged by external forces, which limits their diverse applications. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a recyclable high-performance bionic supramolecular elastomer and a preparation method thereof.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] The present invention provides a preparation method of a recyclable high-performance bionic supramolecular elastomer. After swelling a second network monomer solution in a first cross-linked network and then cross-linking, the recyclable high-performance bionic supramolecular elastomer is obtained;

[0008] The first cross-linked network is prepared by a click reaction using a vinyl-based ionic liquid, polyethylene glycol diacrylate, and a photoinitiator;

[0009] The second network monomer solution is obtained by mixing lipoic acid, an imidazole-based ionic liquid, a catechol-functionalized hyperbranched polymer, and a solvent;

[0010] The structural formula of the catechol-functionalized hyperbranched polymer is shown in General Formula (1), General Formula (2), or General Formula (3):

[0011]

[0012] Among them, R 1 is represented as

[0013] Each * represents the position connected to R 2 , l is 1, m is 0 or 1, and n is 0 or 1;

[0014] R 2 is represented as

[0015] Each ** represents the position connected to R 1 or R 3 ;

[0016] R 3 is represented as *** represents the position connected to R 2 .

[0017] Based on the above technical solutions, the present invention can also be improved as follows.

[0018] Further, the ionic monomer in the vinyl-based ionic liquid is 1-benzyl-3-vinylimidazolium chloride ([VBM Im]Cl), 1-methyl-3-(4-vinylbenzyl)-1-imidazole-3-chloride, sodium 4-styrenesulfonate (NaSS), acryloyloxyethyltrimethylammonium chloride (CIAETMA), acrylic acid (AAC), 2-acrylamido-2-methylpropanesulfonic acid sodium salt (AMPS).

[0019] Further, the process of the click reaction is to mix the vinyl-based ionic liquid, the polyethylene glycol diacrylate, and the photoinitiator, and irradiate with ultraviolet light of 400W - 800W for 5 - 10 minutes; the mass ratio of the vinyl-based ionic liquid, the polyethylene glycol diacrylate, and the photoinitiator is 1:0.0155 - 0.1388:0.0201 - 0.0214.

[0020] Further, the imidazole-based ionic liquid is one of ethyl-3-methylimidazolium ethyl sulfate, butyl-3-methylimidazolium methyl sulfate, ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, butyl-3-methylimidazolium dibutyl phosphate, ethyl-3-methylimidazolium methyl sulfate, ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and butyl-3-methylimidazolium octyl sulfate.

[0021] Further, the solvent is one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, N,N-dimethylformamide, and dichloromethane.

[0022] Further, the swelling time is 4 - 8 hours, the cross-linking temperature is 50 - 80 °C, and the cross-linking time is 1 - 3 hours; the mass ratio of lipoic acid, the imidazole-based ionic liquid, the catechol-functionalized hyperbranched polymer, and the solvent is 1:0.15 - 0.26:0.79 - 59.88:8.18 - 307.37.

[0023] The present invention also provides a recyclable high-performance biomimetic supramolecular elastomer prepared by the method as described above.

[0024] The present invention also provides a method for recycling the biomimetic supramolecular elastomer as described above, which degrades the biomimetic supramolecular elastomer with an alkaline solution to obtain lipoic acid monomers.

[0025] Further, it includes the following steps: soaking the biomimetic supramolecular elastomer in the alkaline solution, degrading for 0.5 - 2 hours under normal pressure and at 25 °C to obtain a degradation solution; adjusting the pH value of the degradation solution to 7, and then successively performing filtration, washing with water, and drying to obtain the lipoic acid monomers.

[0026] Further, the concentration of the alkaline solution is 0.5 - 2 mol / L.

[0027] The beneficial effects of the present invention are as follows:

[0028] (1) The preparation method of the recyclable high-performance biomimetic supramolecular elastomer of the present invention has a simple preparation process, mild reaction conditions, short reaction time, low raw material cost, and is suitable for industrial production;

[0029] (2) The preparation method of the recyclable high-performance biomimetic supramolecular elastomer of the present invention simultaneously realizes the enhancement, recycling, and functionalization of the recyclable high-performance biomimetic supramolecular elastomer, providing guarantee for the multifunctional application of biomimetic intelligent materials;

[0030] (3) The recyclable high-performance bionic supramolecular elastomer of the present invention has excellent mechanical properties and realizes arbitrary adjustment between two states of high mechanical strength and high flexibility;

[0031] (4) The recyclable high-performance bionic supramolecular elastomer of the present invention can be efficiently recycled in a closed loop, and after three recycles, the mechanical property retention rate of the material is 100%;

[0032] (5) The recyclable high-performance bionic supramolecular elastomer of the present invention provides guarantee for the multifunctional application of bionic intelligent materials;

[0033] (6) The recycling method of the bionic supramolecular elastomer of the present invention realizes the efficient closed-loop recycling of the recyclable high-performance bionic supramolecular elastomer, and the recycling method has simple steps, mild conditions and high efficiency. Detailed Embodiments

[0034] The principles and features of the present invention will be described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0035] The preparation method of the recyclable high-performance bionic supramolecular elastomer of the present invention is to swell the second network monomer solution in the first crosslinked network and then crosslink it to obtain the recyclable high-performance bionic supramolecular elastomer; the first crosslinked network is prepared by click reaction using vinyl-based ionic liquid, polyethylene glycol diacrylate and photoinitiator; the second network monomer solution is obtained by mixing lipoic acid, imidazole-based ionic liquid, catechol-functionalized hyperbranched polymer and solvent; the structural formula of the catechol-functionalized hyperbranched polymer is shown as general formula (1), general formula (2) or general formula (3):

[0036]

[0037]

[0038] Among them, R 1 is represented as

[0039] Each * represents the position connected to R 2 , l is 1, m is 0 or 1, and n is 0 or 1;

[0040] R 2 is represented as

[0041] Each ** represents the position connected to R 1 or R 3 ;

[0042] R3 Denoted as *** Denotes the position connected to R 2 Connection position

[0043] The preparation method of the recyclable high-performance bionic supramolecular elastomer of the present invention has simple preparation process, mild reaction conditions, short reaction time, low raw material cost, and is suitable for industrial production; the obtained recyclable high-performance bionic supramolecular elastomer has excellent mechanical properties, realizing arbitrary adjustment between two states of high strength and high flexibility; at the same time, this bionic supramolecular elastomer has good recyclable and reusable properties.

[0044] The preparation method of the present invention simultaneously realizes the enhancement, recycling and functionalization of the recyclable high-performance bionic supramolecular elastomer, providing guarantee for the multi-functional application of bionic intelligent materials.

[0045] The recyclable high-performance bionic supramolecular elastomer of the present invention can be efficiently recycled in a closed loop, and after three recycles, the mechanical property retention rate of the material is 100%.

[0046] In the preparation method of the present invention, the ionic monomer in the vinyl-based ionic liquid used for preparing the first crosslinked network is one of the following: 1-benzyl-3-vinylimidazolium chloride ([VBM Im]Cl), 1-methyl-3-(4-vinylbenzyl)-1-imidazole-3-chloride, sodium 4-styrenesulfonate (NaSS), acryloyloxyethyltrimethylammonium chloride (CIAETMA), acrylic acid (AAC), 2-acrylamido-2-methylpropanesulfonic acid sodium salt (AMPS).

[0047] The chemical formulas of the above ionic monomers are as follows:

[0048]

[0049] Preferably, in the preparation method of the present invention, the specific process of the click reaction for preparing the first crosslinked network is to mix the vinyl-based ionic liquid, polyethylene glycol diacrylate and photoinitiator, and irradiate with ultraviolet light with a power of 400W - 800W for 5 - 10 minutes; the mass ratio of the vinyl-based ionic liquid, polyethylene glycol diacrylate and photoinitiator is 1:0.0155 - 0.1388:0.0201 - 0.0214.

[0050] Preferably, the photoinitiator is one of 4-dimethylaminopyridine, benzophenone, p-aminopropiophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone.

[0051] Preferably, the molecular weight of polyethylene glycol diacrylate is 400 - 1000 g / mol.

[0052] In the preparation method of the present invention, the swelling time of the second network monomer solution is 4 - 8 hours, the crosslinking temperature is 50 - 80 °C, and the crosslinking time is 1 - 3 hours; the mass ratio of lipoic acid, imidazolium ionic liquid, catechol-functionalized hyperbranched polymer and solvent is 1:0.15 - 0.26:0.79 - 59.88:8.18 - 307.37.

[0053] Preferably, the imidazole-based ionic liquid is one of ethyl-3-methylimidazolium ethyl sulfate, butyl-3-methylimidazolium methyl sulfate, ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, butyl-3-methylimidazolium dibutyl phosphate, ethyl-3-methylimidazolium methyl sulfate, ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and butyl-3-methylimidazolium octyl sulfate.

[0054] Preferably, the solvent is one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, N,N-dimethylformamide, and dichloromethane.

[0055] Preferably, the number average molecular weight of the catechol-functionalized hyperbranched polymer is 1200 - 95000 g / mol, and the hydroxyl value is 10 - 280 mg KOH / g.

[0056] Preferably, the preparation method of the catechol-functionalized hyperbranched polymer includes the following steps:

[0057] (a) Dissolve dopamine hydrochloride, acrylate monomer, and acrylamide monomer in a solvent, mix well, adjust the pH value to 8, and react at 100 - 120 °C for 3 - 5 hours.

[0058] (b) After the reaction, remove the solvent and dry the reaction product at 80 - 100 °C for 6 - 8 hours to obtain the catechol-functionalized hyperbranched polymer.

[0059] Preferably, in the above step (a), the acrylate monomer is one of glycerol propoxylated triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate. The acrylamide monomer is one of hexamethylenebisacrylamide, N,N'-methylenebisacrylamide, poly(ethylene glycol) diacrylate, N,N'-vinylbisacrylamide, and N,N'-(propane-1,3-diyl) diacrylamide.

[0060] Preferably, the solvent in the above step (a) is one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, dichloromethane, and dimethyl sulfoxide.

[0061] Preferably, the molar ratio of dopamine hydrochloride, acrylate monomer, acrylamide monomer and solvent in the above step (a) is 1:(0.33 - 0.83):(1 - 1.75):(2.33 - 3.58).

[0062] The recycling method of the biomimetic supramolecular elastomer of the present invention uses an alkaline solution to degrade the biomimetic supramolecular elastomer of the present invention and obtain lipoic acid monomers; this recycling method has simple steps, mild conditions, high efficiency, and can achieve 100% recycling and reuse of the elastomer. At the same time, the recycled and reused elastomer can still maintain good mechanical properties.

[0063] Preferably, the recycling method of the present invention includes the following steps:

[0064] Soak the biomimetic supramolecular elastomer in an alkaline solution, and degrade it for 0.5 - 2 hours under normal pressure and at 25°C to obtain a degradation solution; adjust the pH value of the degradation solution to 7, and then filter, wash with water and dry in sequence to obtain lipoic acid monomers.

[0065] Preferably, the concentration of the alkaline solution is 0.5 - 2 mol / L.

[0066] Preferably, the alkaline solution is one of an aqueous solution of sodium hydroxide, an aqueous solution of potassium hydroxide, an aqueous solution of sodium carbonate, and an aqueous solution of potassium carbonate.

[0067] Preferably, the drying temperature is 80 - 100°C and the time is 4 - 6 hours.

[0068] The lipoic acid monomers prepared by the recycling method of the present invention can be used again to prepare the biomimetic supramolecular elastomer of the present invention.

[0069] Example 1

[0070] In this example, the method of the present invention was used to prepare a recyclable high-performance biomimetic supramolecular elastomer, and then it was recycled.

[0071] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this example is as follows:

[0072] (1) Preparation of catechol-functionalized hyperbranched polymer: 18.7 g of glycerol propoxylated triacrylate, 20.0 g of dopamine hydrochloride (DOPA) and 29.4 g of hexamethylene bisacrylamide were dissolved in 100 g of dimethyl sulfoxide, mixed evenly, adjusted the pH value to 8, reacted at 120°C for 3 hours, removed dimethyl sulfoxide after the reaction, and dried the reaction product at 80°C for 8 hours to obtain catechol-functionalized hyperbranched polymer.

[0073] The number average molecular weight measured by GPC was 1560 g / mol, and the hydroxyl value was 215.7 mgKOH / g.

[0074] (2) After mixing 20.0 g of 1-benzyl-3-vinylimidazolium chloride, 200.0 mg of polyethylene glycol diacrylate (Mn = 400 g / mol), and 202.0 mg of 1-hydroxycyclohexyl phenyl ketone, a click reaction was carried out under ultraviolet light with a power of 400 W for 7 minutes to obtain a first crosslinked network.

[0075] (3) 6.7 g of lipoic acid, 1.5 g of 1-ethyl-3-methylimidazolium ethyl sulfate, and 10.1 g of catechol-functionalized hyperbranched polymer were dissolved in 9.3 g of methanol to obtain a second network monomer solution.

[0076] (4) After swelling the second network monomer solution in the first crosslinked network for 4 hours, crosslinking was carried out at 50 °C for 3 hours to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0077] The recycling process of the biomimetic supramolecular elastomer in this example is as follows:

[0078] 10.0 g of the above recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of 0.5 mol / L aqueous sodium hydroxide solution, and after degradation at normal pressure and 25 °C for 2 hours, a degradation solution was obtained; the degradation solution was neutralized to a pH of 7, filtered and washed three times with water, and dried at 80 °C for 6 hours to obtain recycled lipoic acid monomer.

[0079] Using the recycled lipoic acid monomer, the biomimetic supramolecular elastomer was prepared and recycled again according to the above steps, and three recycling uses were completed.

[0080] Example 2

[0081] In this example, the method of the present invention was used to prepare a recyclable high-performance biomimetic supramolecular elastomer and then recycle it.

[0082] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this example is as follows:

[0083] (1) Preparation of catechol-functionalized hyperbranched polymer: 12.9 g of trimethylolpropane triacrylate, 20.0 g of dopamine hydrochloride (DOPA), and 20.1 g of N,N'-methylenebisacrylamide were dissolved in 90 g of methanol, mixed evenly, adjusted to a pH of 8, reacted at 120 °C for 3 hours, and after the reaction, methanol was removed, and the reaction product was dried at 80 °C for 4 hours to obtain catechol-functionalized hyperbranched polymer.

[0084] The number average molecular weight measured by GPC was 1218 g / mol, and the hydroxyl value was 276.3 mg KOH / g.

[0085] (2) 20.0 g of sodium 4-styrenesulfonate, 181.7 mg of polyethylene glycol diacrylate (Mn = 400 g / mol), and 201.8 mg of 1-hydroxycyclohexyl phenyl ketone were mixed and irradiated with ultraviolet light at a power of 400 W for 6 minutes to carry out a click reaction, obtaining a first crosslinked network.

[0086] (3) 6.7 g of lipoic acid, 1.6 g of 1-butyl-3-methylimidazolium dibutyl phosphate salt, and 7.9 g of catechol-functionalized hyperbranched polymer were dissolved in 8.1 g of ethanol to obtain a second network monomer solution.

[0087] (4) After swelling the second network monomer solution in the first crosslinked network for 5 hours, it was crosslinked at 80 °C for 1 hour to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0088] The recycling process of the biomimetic supramolecular elastomer in this example is as follows:

[0089] The above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of 1.0 mol / L sodium hydroxide aqueous solution and degraded at normal pressure and 25 °C for 1 hour to obtain a degradation solution; the degradation solution was neutralized to a pH value of 7, filtered, washed three times with water, and dried at 100 °C for 4 hours to obtain the recycled lipoic acid monomer.

[0090] Using the recycled lipoic acid monomer, the biomimetic supramolecular elastomer was prepared and recycled again according to the above steps, completing three recycling uses.

[0091] Example 3

[0092] In this example, the method of the present invention was used to prepare a recyclable high-performance biomimetic supramolecular elastomer and then recycle it.

[0093] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this example is as follows:

[0094] (1) Preparation of catechol-functionalized hyperbranched polymer: 12.9 g of pentaerythritol triacrylate, 20.0 g of dopamine hydrochloride (DOPA), and 161.0 g of poly(ethylene glycol) diacrylamide were dissolved in 200 g of tetrahydrofuran. After mixing evenly, the pH value was adjusted to 8, and the reaction was carried out at 100 °C for 5 hours. After the reaction, tetrahydrofuran was removed, and the reaction product was dried at 80 °C for 8 hours to obtain a catechol-functionalized hyperbranched polymer.

[0095] The number average molecular weight measured by GPC was 11855 g / mol, and the hydroxyl value was 28.4 mg KOH / g.

[0096] (2) After mixing 20.0 g of acryloyloxyethyltrimethylammonium chloride, 155.4 mg of polyethylene glycol diacrylate (Mn = 600 g / mol), and 201.5 mg of 1-hydroxycyclohexyl phenyl ketone, a click reaction was carried out under ultraviolet light with a power of 400 W for 5 minutes to obtain the first crosslinked network.

[0097] (3) 6.7 g of lipoic acid, 2.5 g of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 7.8 g of catechol-functionalized hyperbranched polymer were dissolved in 43.1 g of 1,4-dioxane to obtain the second network monomer solution.

[0098] (4) After swelling the second network monomer solution in the first crosslinked network for 4 hours, crosslinking was carried out at 50 °C for 3 hours to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0099] The recycling process of the biomimetic supramolecular elastomer in this example is as follows:

[0100] 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of 2.0 mol / L sodium hydroxide aqueous solution, and after degradation at normal pressure and 25 °C for 0.5 hours, a degradation solution was obtained; the degradation solution was neutralized to a pH value of 7, filtered and washed three times with water. After drying at 100 °C for 4 hours, the recycled lipoic acid monomer was obtained.

[0101] Using the recycled lipoic acid monomer, the biomimetic supramolecular elastomer was prepared and recycled again according to the above steps, and three recycling uses were completed.

[0102] Example 4

[0103] In this example, the method of the present invention was used to prepare a recyclable high-performance biomimetic supramolecular elastomer and then recycle it.

[0104] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this example is as follows:

[0105] (1) Preparation of catechol-functionalized hyperbranched polymer: 51.2 g of ethoxylated trimethylolpropane triacrylate, 20.0 g of dopamine hydrochloride (DOPA), and 21.9 g of N,N'-divinyl bisacrylamide were dissolved in 100 g of ethyl acetate, mixed evenly, the pH value was adjusted to 8, and the reaction was carried out at 110 °C for 4 hours. After the reaction, ethyl acetate was removed, and the reaction product was dried at 90 °C for 7 hours to obtain the catechol-functionalized hyperbranched polymer.

[0106] The number average molecular weight measured by GPC was 2140 g / mol, and the hydroxyl value was 157.3 mg KOH / g.

[0107] (2) After mixing 20.0 g of acrylic acid, 310.7 mg of polyethylene glycol diacrylate (Mn = 600 g / mol), and 203.1 mg of 1-hydroxycyclohexyl phenyl ketone, a click reaction was carried out under ultraviolet light with a power of 400 W for 8 minutes to obtain the first cross-linked network.

[0108] (3) 6.7 g of lipoic acid, 2.2 g of 1-butyl-3-methylimidazolium dibutyl phosphate salt, and 13.8 g of catechol-functionalized hyperbranched polymer were dissolved in 18.8 g of N,N-dimethylformamide to obtain the second network monomer solution.

[0109] (4) After swelling the second network monomer solution in the first cross-linked network for 6 hours, cross-linking was carried out at 80 °C for 1 hour to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0110] The recycling process of the biomimetic supramolecular elastomer in this example is as follows:

[0111] 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of 0.5 mol / L sodium hydroxide aqueous solution, and after degradation at normal pressure and 25 °C for 2 hours, a degradation solution was obtained; the degradation solution was neutralized to a pH value of 7, filtered and washed three times with water, and dried at 100 °C for 4 hours to obtain the recycled lipoic acid monomer.

[0112] Using the recycled lipoic acid monomer, the biomimetic supramolecular elastomer was prepared and recycled again according to the above steps, and three recycling uses were completed.

[0113] Example 5

[0114] In this example, the method of the present invention was used to prepare a recyclable high-performance biomimetic supramolecular elastomer and then recycle it.

[0115] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this example is as follows:

[0116] (1) Preparation of catechol-functionalized hyperbranched polymer: 20.46 g of propoxylated trimethylolpropane triacrylate, 20.0 g of dopamine hydrochloride (DOPA), and 23.8 g of N,N'-(propane-1,3-diyl)bisacrylamide were dissolved in 120 g of dichloromethane. After mixing evenly, the pH value was adjusted to 8, and the reaction was carried out at 120 °C for 3 hours. After the reaction, dichloromethane was removed, and the reaction product was dried at 100 °C for 6 hours to obtain the catechol-functionalized hyperbranched polymer.

[0117] The number average molecular weight measured by GPC was 1476 g / mol, and the hydroxyl value was 228.0 mg KOH / g.

[0118] (2) After mixing 20.0 g of sodium 2-acrylamido-2-methylpropanesulfonate, 1.4 g of polyethylene glycol diacrylate (Mn = 1000 g / mol), and 213.9 mg of 1-hydroxycyclohexyl phenyl ketone, a click reaction was carried out under ultraviolet light with a power of 400 W for 10 minutes to obtain a first crosslinked network.

[0119] (3) 6.7 g of lipoic acid, 1.5 g of 1-ethyl-3-methylimidazolium methyl sulfate, and 9.6 g of catechol-functionalized hyperbranched polymer were dissolved in 8.9 g of dichloromethane to obtain a second network monomer solution.

[0120] (4) After swelling the second network monomer solution in the first crosslinked network for 4 hours, crosslinking was carried out at 60 °C for 2 hours to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0121] The recycling process of the biomimetic supramolecular elastomer in this example is as follows:

[0122] 10.0 g of the above recyclable high-performance biomimetic supramolecular elastomer was immersed in 80 mL of 2 mol / L sodium hydroxide aqueous solution, and after degradation at normal pressure and 25 °C for 0.5 hours, a degradation solution was obtained; the degradation solution was neutralized to a pH value of 7, filtered and washed three times with water, and dried at 90 °C for 5 hours to obtain the recycled lipoic acid monomer.

[0123] Using the recycled lipoic acid monomer, the biomimetic supramolecular elastomer was prepared and recycled again according to the above steps, and three recycling uses were completed.

[0124] Example 6

[0125] In this example, the method of the present invention was used to prepare a recyclable high-performance biomimetic supramolecular elastomer and then recycle it.

[0126] The preparation process of the recyclable high-performance biomimetic supramolecular elastomer in this example is as follows:

[0127] (1) Preparation of catechol-functionalized hyperbranched polymer: 51.8 g of ethoxylated trimethylolpropane triacrylate, 20.0 g of dopamine hydrochloride (DOPA), and 483.09 g of poly(ethylene glycol) diacrylamide were dissolved in 500 g of toluene, mixed evenly, adjusted to a pH value of 8, and reacted at 100 °C for 6 hours. After the reaction, toluene was removed, and the reaction product was dried at 100 °C for 6 hours to obtain catechol-functionalized hyperbranched polymer.

[0128] The number average molecular weight measured by GPC was 91298 g / mol, and the hydroxyl value was 14.7 mg KOH / g.

[0129] (2) Mix 20.0 g of 1-benzyl-3-vinylimidazolium chloride, 483.0 mg of polyethylene glycol diacrylate (Mn = 1000 g / mol), and 204.8 mg of 1-hydroxycyclohexyl phenyl ketone, and irradiate with ultraviolet light at a power of 400 W for 7 minutes to carry out a click reaction to obtain a first crosslinked network.

[0130] (3) Dissolve 6.7 g of lipoic acid, 2.5 g of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 59.8 g of catechol-functionalized hyperbranched polymer in 50.1 g of xylene to obtain a second network monomer solution.

[0131] (4) After swelling the second network monomer solution in the first crosslinked network for 5 hours, crosslink at 70 °C for 1.5 hours to obtain a recyclable high-performance biomimetic supramolecular elastomer.

[0132] The recycling process of the biomimetic supramolecular elastomer in this example is as follows:

[0133] Soak 10.0 g of the above-mentioned recyclable high-performance biomimetic supramolecular elastomer in 80 mL of 1 mol / L sodium hydroxide aqueous solution, and degrade at normal pressure and 25 °C for 1 hour to obtain a degradation solution; neutralize the degradation solution to a pH value of 7, filter and wash three times with water, and dry at 100 °C for 4 hours to obtain the recycled lipoic acid monomer.

[0134] Use the recycled lipoic acid monomer to prepare the biomimetic supramolecular elastomer again and recycle it according to the above steps to complete three recycling uses.

[0135] Comparative Example 1

[0136] Mix 20.0 g of acryloyloxyethyltrimethylammonium chloride, 460.0 mg of polyethylene glycol diacrylate (Mn = 1000 g / mol), and 202.8 mg of 1-hydroxycyclohexyl phenyl ketone, and irradiate with ultraviolet light at a power of 400 W for 8 minutes to carry out a click reaction to obtain a first crosslinked network, that is, a poly-1-methyl-3-(4-vinylbenzyl)-1-imidazolium-3-chloride network. This network cannot be recycled.

[0137] Comparative Example 2

[0138] Dissolve 6.7 g of lipoic acid, 2.2 g of 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and 4.5 g of catechol-functionalized hyperbranched polymer in 18.1 g of methanol, and crosslink at 70 °C for 1.5 hours to obtain a second network, that is, a polythiol network.

[0139] The recycling process of the polythiol network in this example is as follows:

[0140] 10.0 g of the above-mentioned polythioctic acid network was immersed in 80 mL of 1 mol / L aqueous sodium hydroxide solution and degraded for 2 hours at normal pressure and 25 °C to obtain a degradation solution; the degradation solution was neutralized to a pH value of 7, filtered and washed three times with water, and dried at 100 °C for 4 hours to obtain the recovered lipoic acid monomer.

[0141] The recovered lipoic acid monomer was used to prepare the polythioctic acid network again according to the above steps and recovered, and three cycles of recovery were completed.

[0142] For the above-mentioned examples and comparative examples, the mechanical properties of the supramolecular elastomers before recovery were detected, and the detection results are shown in Table 1. The detection results of the mechanical properties of the elastomers in Examples 1-6 after three cycles of recovery are shown in Table 2.

[0143] Table 1 Mechanical properties of the elastomers in each example and comparative example

[0144]

[0145] According to the detection results in Table 1, it can be seen that for the elastomers in Examples 1-6, the comprehensive results of tensile strength, elongation at break, and fracture toughness are all better than those of Comparative Examples 1 and 2. This shows that the elastomers in Examples 1-6 can achieve arbitrary adjustment between the two states of high mechanical strength and high flexibility.

[0146] Table 2 Mechanical properties of the elastomers in each example after three cycles of recovery

[0147]

[0148]

[0149]

[0150] It can be seen from Table 2 that the elastomers in Examples 1-6 can still maintain excellent mechanical properties after three cycles of recovery. This shows that the biomimetic supramolecular elastomer of the present invention can be efficiently recycled in a closed loop, and after three cycles of recovery, the retention rate of the mechanical properties of the material is 100%. The network of Comparative Example 1 cannot be recycled. The network of Comparative Example 2 can be recycled, but its retention rate of performance after three cycles of recovery is only 10%, and the retention rate of performance is low.

[0151] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a recyclable high-performance biomimetic supramolecular elastomer, characterized in that: Swelling the second network monomer solution in the first cross-linked network and then cross-linking it to obtain the recyclable high-performance biomimetic supramolecular elastomer; The first cross-linked network is prepared by a click reaction using a vinyl ionic liquid, polyethylene glycol diacrylate and a photoinitiator; The second network monomer solution is obtained by mixing lipoic acid, imidazole ionic liquid, catechol functionalized hyperbranched polymer and solvent; The structural formula of the catechol functionalized hyperbranched polymer is shown in general formula (1), general formula (2) or general formula (3): Among them, R1 is expressed as Each * indicates the position of connection with R2, l is 1, m is 0 or 1, and n is 0 or 1; R2 is expressed as Each ** indicates the position of connection with R1 or R3; R3 is expressed as *** indicates the position of connection with R2.

2. The method for preparing a recyclable high-performance biomimetic supramolecular elastomer according to claim 1, characterized in that: The ionic monomer in the vinyl ionic liquid is one of 1-benzyl-3-vinylimidazolium chloride, 1-methyl-3-(4-vinylbenzyl)-1-imidazole-3-chloride, 4-styrenesulfonic acid sodium salt, acryloyloxyethyltrimethylammonium chloride, acrylic acid, and 2-acrylamido-2-methylpropanesulfonate sodium.

3. The method for preparing a recyclable high-performance biomimetic supramolecular elastomer according to claim 2, characterized in that: The click reaction process is to mix the vinyl ionic liquid, the polyethylene glycol diacrylate and the photoinitiator, and irradiate with ultraviolet light with a power of 400W to 800W for 5 to 10 minutes; the mass ratio of the vinyl ionic liquid, the polyethylene glycol diacrylate and the photoinitiator is 1:0.0155-0.1388:0.0201-0.0214.

4. The method for preparing a recyclable high-performance biomimetic supramolecular elastomer according to claim 1, characterized in that: The imidazole ionic liquid is one of 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide, 1-butyl-3-methylimidazolium dibutyl phosphate, 1-ethyl-3-methylimidazolium methyl sulfate, 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide, and 1-butyl-3-methylimidazolium octyl sulfate.

5. The method for preparing a recyclable high-performance biomimetic supramolecular elastomer according to claim 4, characterized in that: The solvent is one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, ethyl acetate, N'N-dimethylformamide and dichloromethane.

6. The method for preparing a recyclable high-performance biomimetic supramolecular elastomer according to claim 5, characterized in that: The swelling time is 4-8 hours, the cross-linking temperature is 50-80°C, and the cross-linking time is 1-3 hours; the mass ratio of the lipoic acid, the imidazole ionic liquid, the catechol functionalized hyperbranched polymer and the solvent is 1: 0.15-0.26: 0.79-59.88: 8.18-307.

37.

7. A recyclable high-performance biomimetic supramolecular elastomer, characterized in that: The method is prepared according to any one of claims 1 to 6.

8. A method for recovering a biomimetic supramolecular elastomer as claimed in claim 7, characterized in that: The biomimetic supramolecular elastomer is degraded by using an alkaline solution to obtain lipoic acid monomers.

9. The method for recovering a biomimetic supramolecular elastomer according to claim 8, characterized in that: The following steps are involved: The bionic supramolecular elastomer is immersed in the alkaline solution and degraded for 0.5-2 hours at normal pressure and 25° C. to obtain a degradation solution; the pH value of the degradation solution is adjusted to 7, and then filtered, washed with water and dried in sequence to obtain the lipoic acid monomer.

10. The method for recovering a biomimetic supramolecular elastomer according to claim 9, characterized in that: The concentration of the alkaline solution is 0.5-2 mol / L.

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