High-strength and self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry and preparation method

Abstract

The present invention relates to a high-toughness self-healing supramolecular polyurethane elastomer based on thiolactone chemistry and a preparation method thereof. A novel diol chain extender with a suspended 2-urea-4[1H]-pyrimidinone (UPy) motif and an imidazole ligand is synthesized by a one-pot two-step "amine-mercapto-acrylate" coupling reaction of thiolactone, which is then introduced into polyurethane, and further cross-linked by metal ions to obtain a supramolecular polyurethane elastomer. UPy quadruple hydrogen bonds and metal-imidazole coordination serve as dynamic crosslinking points and sacrificial bonds, playing a synergistic role in the strengthening and toughening of the elastomer. At the same time, the reversible recombination of hydrogen bonds and coordination bonds and the higher mobility of the side chains give the material the ability to gently repair damage. Compared with single supramolecular systems based on UPy quadruple hydrogen bonds or metal-imidazole coordination, the elastomer has better mechanical properties and shows great application potential in the fields of flexible electronics and wearable devices.

Description

Technical Field

[0001] The present invention belongs to the field of functional polymer materials and relates to a self-repairing supramolecular elastomer and a preparation method thereof, and in particular to a high-strength and tough self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry and a preparation method thereof. Background Art

[0002] Elastomers are polymer materials that undergo significant deformation under weak external forces and then recover to near-initial dimensions and shape upon removal of the force. Compared to other materials, elastomers exhibit viscoelastic properties, weak intermolecular forces, low Young's modulus, and high elongation at break. Consequently, they are widely used in tires, sealants, surface protective coatings, wearable electronic devices, shape memory materials, and physiological health monitoring. However, over long periods of service, elastomers inevitably develop microcracks or localized damage, leading to performance failure and premature obsolescence. Given the current severe global resource and environmental burdens, researchers are committed to introducing dynamic covalent bonds (such as Diels-Alder bonds, disulfide bonds, borate ester bonds, imine bonds, and oxime-carbamate bonds) or supramolecular interactions (such as hydrogen bonds, metal coordination, ionic interactions, and π-π stacking) into elastomers to impart intrinsic self-healing properties and thus extend their service life. However, an irreconcilable contradiction between mechanical properties and dynamic healing capabilities has severely restricted the practical application and development of self-healing elastomers.

[0003] In order to solve the above problems, researchers have proposed a series of strategies in recent years, among which phase regulation and sacrificial bonds have been widely accepted and successfully proven. Since the degree of phase separation and the size of microphase domains are closely related to the macroscopic properties of the material, they are often difficult to control accurately, and the application of phase regulation is limited to a certain extent. In comparison, sacrificial bonds strengthen and toughen elastomers through dynamic cross-linking and energy dissipation mechanisms. At the same time, their reversible reorganization at the cross section can promote repair, showing great advantages. Li et al. achieved high strength (48.5MPa) and high toughness (386.5MJ / m by introducing UPy quadruple hydrogen bonds in polyurethane. 3 ), however, the material needs to be repaired at a higher temperature (100°C) (Angew.Chem.Int.Ed., 2018, 57, 13838-13842). Fu et al. used Zn 2+ A supramolecular hybrid polymer with ultra-strong stretchability and rapid room-temperature self-healing was designed using imidazole coordination, but its maximum tensile strength is only 0.32 MPa, which is insufficient for practical applications (Chem. Mater., 2018, 30, 6026-6039). Therefore, there is an urgent need to develop elastomers with high strength and toughness and mild repair conditions.

[0004] Thiolactones are five-membered sulfur-containing compounds that can be ring-opened by primary amines in the absence of catalysts, simultaneously releasing a thiol group in situ. This thiol group can then react with alkenes, alkynes, epoxies, acrylates, isocyanates, and other compounds to achieve a one-pot, two-step bifunctionalization. Due to the simplicity, high efficiency, and lack of small molecule byproducts of this method, thiolactone chemistry provides an effective platform for the on-demand customization of elastomers. Summary of the Invention

[0005] Technical problems to be solved

[0006] To overcome the shortcomings of the prior art, the present invention proposes a high-strength, self-healing supramolecular polyurethane elastomer based on thiolactone chemistry and a preparation method thereof. Thiolactone chemistry is used as a bridge to simultaneously bind UPy motifs and imidazole ligands to the side chains of linear polyurethanes. Through the synergistic effect of multiple hydrogen bonds and metal-imidazole coordination, the difficult problem of the inability to balance the mechanical properties and dynamic repair capabilities of the elastomer is cleverly solved.

[0007] Technical Solution

[0008] A method for preparing a high-strength and self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry, characterized by the following steps:

[0009] Step 1, preparation of thiolactone diol: under nitrogen protection, α-isocyanate-γ-thiolactone and aminodiol are added to solvent A, and stirred at room temperature for 0.5 to 3 hours to obtain thiolactone diol; the molar ratio of the α-isocyanate-γ-thiolactone to the aminodiol is 1:1 to 2:1;

[0010] Step 2: Preparation of a diol chain extender having supramolecular interaction sites: Under nitrogen protection, aminoimidazole, UPy-modified acrylate, and a basic catalyst are sequentially added to the system of step 1, and the mixture is reacted at 30-60° C. for 3-12 hours to obtain a diol chain extender having a pendant UPy unit and an imidazole ligand; the molar ratio of the thiolactone diol, aminoimidazole, and UPy-modified acrylate is 1:0.8:0.8 to 1:1:1;

[0011] The chemical structure of the UPy-modified acrylate is:

[0012]

[0013] Wherein: R is H or CH3;

[0014] Step 3, preparation of linear polyurethane: Under nitrogen protection, a macromolecular diol, a diisocyanate, and a catalyst are dissolved in solvent A and added to the system of step 2, reacted at 60-100° C. for 3-6 hours to obtain an isocyanate-terminated prepolymer, and then a small molecule diol is added and stirred for 5-17 hours, and finally precipitated in solvent B to obtain a linear polyurethane; the molar ratio of the macromolecular diol to the diisocyanate is 1:1.5-1:2.8, and the molar percentage of the diol chain extender to the small molecule diol is 10%-50%;

[0015] Step 4. Preparation of a supramolecular polyurethane elastomer based on synergistic dynamic bonds: dissolve the linear polyurethane obtained in step 3 in solvent C to prepare a solution with a mass fraction of 10% to 30%, then add the metal salt solution D thereto, stir at room temperature for 1 to 12 hours, and finally pour the mixed solution into a polytetrafluoroethylene mold, and fully dry at 25 to 80° C. for 24 to 48 hours to obtain a supramolecular polyurethane elastomer based on synergistic dynamic bonds; the molar ratio of the metal salt to the imidazole ligand in the linear polyurethane is 1:3.2 to 1:5.3.

[0016] The amino diols include but are not limited to the following:

[0017]

[0018] Here, n is an integer from 0 to 10.

[0019] The aminoimidazoles include but are not limited to the following:

[0020]

[0021] The macromolecular diol includes but is not limited to: a mixture of one or more of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyester glycol in any proportion, and has a number average molecular weight of 400 to 3000.

[0022] The diisocyanate includes, but is not limited to, a mixture of one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate in any proportion.

[0023] The small molecule diols include but are not limited to: ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediol, hydroquinone bis-β-hydroxyethyl ether, dihydroxyethyl terephthalate, hydrogenated bisphenol A, or one or more thereof mixed in any proportion.

[0024] The metal salt includes, but is not limited to, zinc chloride, zinc acetate, zinc nitrate, zinc trifluoromethanesulfonate, copper chloride, copper nitrate, copper trifluoromethanesulfonate or cobalt trifluoromethanesulfonate.

[0025] The solvent A includes but is not limited to: a mixture of one or more of tetrahydrofuran, dioxane, chloroform, and N,N-dimethylformamide in any proportion; the solvent B includes but is not limited to: a mixture of one or more of ether, petroleum ether, n-hexane, cyclohexane, methanol, ethanol, and deionized water in any proportion; the solvent C includes but is not limited to: a mixture of one or more of dichloromethane, tetrahydrofuran, acetone, N,N-dimethylformamide, and N-methylpyrrolidone in any proportion; the solvent D includes but is not limited to: a mixture of one or more of acetone, tetrahydrofuran, methanol, acetonitrile, and N,N-dimethylformamide in any proportion.

[0026] The alkaline catalyst includes but is not limited to: triethylamine, dimethylphenylphosphine or tributylphosphine; the catalyst includes but is not limited to: triethylamine, triethylenediamine, dibutyltin dilaurate or stannous octoate.

[0027] A high-strength, self-healing supramolecular polyurethane elastomer based on thiolactone chemistry prepared by the method is characterized by: synthesizing a diol chain extender with a pendant 2-urea-4[1H]-pyrimidinone (UPy) motif and an imidazole ligand through a one-pot, two-step "amine-thiol-acrylate" coupling reaction of thiolactone; introducing the diol chain extender into polyurethane, and obtaining a supramolecular polyurethane elastomer through metal ion cross-linking; utilizing the dual functional properties of thiolactone, introducing a high-density reversible sacrificial bond into the polyurethane side chain, thereby obtaining a supramolecular elastomer with both excellent mechanical properties and mild dynamic repair capabilities.

[0028] Beneficial effects

[0029] The present invention proposes a high-strength, self-healing supramolecular polyurethane elastomer based on thiolactone chemistry and its preparation method. A novel diol chain extender with a pendant 2-urea-4[1H]-pyrimidinone (UPy) motif and imidazole ligand is synthesized through a one-pot, two-step "amine-thiol-acrylate" coupling reaction of thiolactone. This diol chain extender is then introduced into polyurethane and further cross-linked using metal ions to obtain a supramolecular polyurethane elastomer. The UPy quadruple hydrogen bonds and metal-imidazole coordination serve as dynamic crosslinking points and sacrificial bonds, playing a synergistic role in strengthening and toughening the elastomer. At the same time, the reversible recombination of hydrogen bonds and coordination bonds and the high mobility of the side chains give the material the ability to gently repair damage. Compared with single supramolecular systems based on UPy quadruple hydrogen bonds or metal-imidazole coordination, the elastomer has superior mechanical properties and shows great application potential in the fields of flexible electronics and wearable devices.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention provides a method for preparing a high-strength and self-healing supramolecular polyurethane elastomer, which innovatively combines thiolactone chemistry with supramolecular effects, providing ideas for the development of high-performance self-healing polyurethane elastomers based on side chain functionalization.

[0032] 2. The present invention makes full use of the synergistic effect of high-density dual reversible sacrificial bonds. The mechanical properties of the prepared supramolecular polyurethane elastomer are significantly better than those of a single supramolecular system based on UPy quadruple hydrogen bond or metal-imidazole coordination, and has broad application prospects.

[0033] 3. Due to the reversible recombination of hydrogen bonds and coordination bonds and the high mobility of side chains, the supramolecular polyurethane elastomer prepared in the present invention can effectively heal surface scratches at 60°C, and the repair efficiency of tensile strength and elongation at break both reached 78% after 24 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 : Schematic diagram of the structure of the supramolecular polyurethane elastomer prepared in Example 3

[0035] Figure 2 : Initial stress-strain curve of supramolecular polyurethane elastomer (a) and mechanical properties comparison (b)

[0036] Figure 3 :Optical microscopy image of scratch repair on the surface of supramolecular polyurethane elastomer (scale bar: 50 μm)

[0037] Figure 4 :Stress-strain curve of supramolecular polyurethane elastomer after repair (a) and summary of repair efficiency (b) DETAILED DESCRIPTION

[0038] The present invention will now be further described with reference to the embodiments and accompanying drawings:

[0039] Example 1:

[0040] Under nitrogen protection, 0.015 mol of α-isocyanate-γ-thiolactone and 0.015 mol of diethanolamine were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h to obtain thiolactone diol; then, 0.015 mol of 2-methyl-1H-imidazole-1-propylamine, 0.015 mol of UPy-modified acrylate and 60 μL of triethylamine were added in sequence and reacted at 40 ° C for 12 h to obtain a new diol chain extender with pendant UPy units and imidazole ligands; 0.05 mol of polytetramethyleneimine ether diol, 0.1 mol of dicyclohexylmethane diisocyanate and 660 μL of dibutyltin dilaurate were added. The obtained product was dissolved in 140 mL of N,N-dimethylformamide and added to the above reaction system, and reacted at 80 ° C for 4 hours to obtain an isocyanate-terminated prepolymer. Then, 0.035 mol of 1,4-butanediol was added and stirring was continued for 17 hours. Then, a linear polyurethane was precipitated in ether. The linear polyurethane was dissolved in tetrahydrofuran to prepare a solution with a mass fraction of 20%. 3.75 mmol of zinc chloride in acetone solution was slowly added thereto and stirred at room temperature for 4 hours. Finally, the mixed solution was poured into a polytetrafluoroethylene mold, evaporated at room temperature for 24 hours, and then dried in a vacuum drying oven at 60 ° C for 24 hours to obtain a supramolecular polyurethane elastomer based on synergistic dynamic bonds.

[0041] Example 2:

[0042] Under nitrogen protection, 0.015 mol of α-isocyanate-γ-thiolactone and 0.015 mol of N,N-bis(2-hydroxyethyl)ethylenediamine were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h to obtain thiolactone diol; then, 0.015 mol of 1-(3-aminopropyl)imidazole, 0.015 mol of UPy-modified acrylate and 120 μL of triethylamine were added in sequence, and the mixture was reacted at 40 ° C for 12 h to obtain a new diol chain extender with pendant UPy units and imidazole ligands; 0.05 mol of polytetramethylene glycol, 0.1 mol of dicyclohexylmethane diisocyanate and 660 μL of dilauryl alcohol were added. Dibutyltin ether was dissolved in 140 mL of N,N-dimethylformamide and added to the above reaction system, and the reaction was carried out at 80°C for 4 h to obtain an isocyanate-terminated prepolymer. Subsequently, 0.035 mol of 1,4-butanediol was added and stirring was continued for 17 h. Subsequently, a linear polyurethane was precipitated in ether. The linear polyurethane was dissolved in tetrahydrofuran to prepare a solution with a mass fraction of 20%. 3.75 mmol of an acetonitrile solution of zinc nitrate was slowly added thereto and stirred at room temperature for 4 h. Finally, the mixed solution was poured into a polytetrafluoroethylene mold, evaporated at room temperature for 24 h, and then dried in a vacuum drying oven at 60°C for 24 h to obtain a supramolecular polyurethane elastomer based on synergistic dynamic bonds.

[0043] Example 3:

[0044] Under nitrogen protection, 0.015 mol of α-isocyanate-γ-thiolactone and 0.015 mol of diethanolamine were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h to obtain thiolactone diol; then, 0.015 mol of 1-(3-aminopropyl)imidazole, 0.015 mol of UPy-modified acrylate and 60 μL of triethylamine were added in sequence and reacted at 40 ° C for 12 h to obtain a new diol chain extender with pendant UPy units and imidazole ligands; 0.05 mol of polytetramethyleneimine ether glycol, 0.1 mol of dicyclohexylmethane diisocyanate and 660 μL of dibutyltin dilaurate were dissolved in 1 20 mL of N,N-dimethylformamide was added to the above reaction system and reacted at 80 ° C for 4 hours to obtain an isocyanate-terminated prepolymer. Then, 0.035 mol of 1,4-butanediol was added and stirring was continued for 6 hours. Then, a linear polyurethane was precipitated in deionized water; the linear polyurethane was dissolved in tetrahydrofuran to prepare a solution with a mass fraction of 20%, and 3.75 mmol of a methanol solution of zinc trifluoromethanesulfonate was slowly added thereto and stirred at room temperature for 4 hours. Finally, the mixed solution was poured into a polytetrafluoroethylene mold, first evaporated at room temperature for 24 hours, and then placed in a vacuum drying oven at 60 ° C for 24 hours to obtain a supramolecular polyurethane elastomer based on synergistic dynamic bonds.

[0045] Example 4:

[0046] Under nitrogen protection, 0.015 mol of α-isocyanate-γ-thiolactone and 0.015 mol of diethanolamine were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h to obtain thiolactone diol; then, 0.015 mol of 1-(3-aminopropyl)imidazole, 0.015 mol of UPy-modified acrylate and 60 μL of triethylamine were added in sequence and reacted at 40 ° C for 12 h to obtain a new diol chain extender with pendant UPy units and imidazole ligands; 0.05 mol of polytetramethyleneimine ether glycol, 0.1 mol of dicyclohexylmethane diisocyanate and 660 μL of dibutyltin dilaurate were dissolved in 1 20 mL of N,N-dimethylformamide was added to the above reaction system and reacted at 80 ° C for 4 hours to obtain an isocyanate-terminated prepolymer. Then, 0.035 mol of 1,4-butanediol was added and stirring was continued for 6 hours. Then, a linear polyurethane was precipitated in deionized water; the linear polyurethane was dissolved in tetrahydrofuran to prepare a solution with a mass fraction of 15%, 4.69 mmol of a methanol solution of zinc trifluoromethanesulfonate was slowly added thereto and stirred at room temperature for 12 hours. Finally, the mixed solution was poured into a polytetrafluoroethylene mold, first evaporated at room temperature for 24 hours, and then placed in a vacuum drying oven at 60 ° C for 24 hours to obtain a supramolecular polyurethane elastomer based on synergistic dynamic bonds.

[0047] Example 5:

[0048] Under nitrogen protection, 0.015 mol of α-isocyanate-γ-thiolactone and 0.015 mol of diethanolamine were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h to obtain thiolactone diol; then, 0.015 mol of 1-(3-aminopropyl)imidazole, 0.015 mol of UPy-modified acrylate and 60 μL of triethylamine were added in sequence and reacted at 40 ° C for 12 h to obtain a new diol chain extender with pendant UPy units and imidazole ligands; 0.05 mol of polytetramethyleneimine ether glycol and 0.1 mol of dicyclohexylmethane diisocyanate were added to the mixture. Cyanate and 660 μL of dibutyltin dilaurate were dissolved in 120 mL of N,N-dimethylformamide and added to the above reaction system. The mixture was reacted at 80°C for 4 h to obtain an isocyanate-terminated prepolymer. Subsequently, 0.035 mol of 1,4-butanediol was added and stirring was continued for 17 h. The linear polyurethane was then precipitated in ether. The linear polyurethane was dissolved in tetrahydrofuran to prepare a solution with a mass fraction of 30%, which was then poured into a polytetrafluoroethylene mold. The solution was first evaporated at room temperature for 24 h and then dried in a vacuum drying oven at 60°C for 24 h to obtain a supramolecular polyurethane elastomer based on UPy hydrogen bonds.

[0049] Example 6:

[0050] Under nitrogen protection, 0.015 mol of α-isocyanate-γ-thiolactone and 0.015 mol of diethanolamine were added to 20 mL of N,N-dimethylformamide and stirred at room temperature for 1 h to obtain thiolactone diol; then, 0.015 mol of 1-(3-aminopropyl)imidazole, 0.015 mol of n-butyl acrylate and 50 μL of triethylamine were added in sequence and reacted at 40 ° C for 12 h to obtain a new diol chain extender with pendant imidazole ligands; 0.05 mol of polytetramethyleneimine ether glycol, 0.1 mol of dicyclohexylmethane diisocyanate and 650 μL of dibutyltin dilaurate were dissolved in 120 mL of N , N-dimethylformamide is added to the above reaction system, and the reaction is carried out at 80°C for 4 hours to obtain an isocyanate-terminated prepolymer, followed by adding 0.035 mol of 1,4-butanediol and continuing to stir for 17 hours, and then precipitating in ether to obtain a linear polyurethane; the linear polyurethane is dissolved in tetrahydrofuran to prepare a solution with a mass fraction of 20%, and 3.75 mmol of a methanol solution of zinc trifluoromethanesulfonate is slowly added thereto and stirred at room temperature for 12 hours, and finally the mixed solution is poured into a polytetrafluoroethylene mold, first evaporated at room temperature for 24 hours, and then placed in a vacuum drying oven at 60°C for 24 hours to obtain a supramolecular polyurethane elastomer based on metal-imidazole coordination.

Claims

1. A method for preparing a high-strength and self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry, characterized in that Here are the steps: Step 1, preparation of thiolactone diol: under nitrogen protection, α -Isocyanate- γ -Thiolactone and aminodiol are added to solvent A and stirred at room temperature for 0.5 to 3 hours to obtain thiolactone diol; α -Isocyanate- γ -The molar ratio of thiolactone to aminodiol is 1:1 to 2:1; Step 2: Preparation of a diol chain extender having supramolecular interaction sites: Under nitrogen protection, aminoimidazole, UPy-modified acrylate, and a basic catalyst are sequentially added to the system of step 1, and the mixture is reacted at 30-60° C. for 3-12 hours to obtain a diol chain extender having a pendant UPy unit and an imidazole ligand; the molar ratio of the thiolactone diol, aminoimidazole, and UPy-modified acrylate is 1:0.8:0.8 to 1:1:1; The chemical structure of the UPy-modified acrylate is: Wherein: R is H or CH3; Step 3, preparation of linear polyurethane: Under nitrogen protection, a macromolecular diol, a diisocyanate, and a catalyst are dissolved in solvent A and added to the system of step 2, reacted at 60-100° C. for 3-6 hours to obtain an isocyanate-terminated prepolymer, and then a small molecule diol is added and stirred for 5-17 hours. Finally, the linear polyurethane is precipitated in solvent B; the molar ratio of the macromolecular diol to the diisocyanate is 1:1.5-1:2.8, and the molar percentage of the diol chain extender to the small molecule diol is 10%-50%; Step 4, preparation of a supramolecular polyurethane elastomer based on synergistic dynamic bonds: dissolving the linear polyurethane obtained in step 3 in solvent C to prepare a solution with a mass fraction of 10% to 30%, then adding a metal salt solution D thereto, stirring at room temperature for 1 to 12 hours to obtain a mixed solution, and finally pouring the mixed solution into a polytetrafluoroethylene mold, and fully drying at 25 to 80° C. for 24 to 48 hours to obtain a supramolecular polyurethane elastomer based on synergistic dynamic bonds; the molar ratio of the metal salt to the imidazole ligand in the linear polyurethane is 1:3.2 to 1:5.3; The aminoimidazoles include the following: 。 2. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The aminodiols include the following: Wherein, n is an integer from 0 to 10.

3. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The macromolecular diol includes: one or more of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyester diol, mixed in any proportion, and has a number average molecular weight of 400-3000.

4. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The diisocyanate includes one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate, mixed in any proportion.

5. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The small molecule diol includes: ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediol, hydroquinone bis-β-hydroxyethyl ether, dihydroxyethyl terephthalate, hydrogenated bisphenol A or one or more thereof mixed in any proportion.

6. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The metal salt includes: zinc chloride, zinc acetate, zinc nitrate, zinc trifluoromethanesulfonate, copper chloride, copper nitrate, copper trifluoromethanesulfonate or cobalt trifluoromethanesulfonate.

7. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The solvent A includes: a mixture of one or more of tetrahydrofuran, dioxane, chloroform, and N,N-dimethylformamide in any proportion; the solvent B includes: a mixture of one or more of ether, petroleum ether, n-hexane, cyclohexane, methanol, ethanol, and deionized water in any proportion; the solvent C includes: a mixture of one or more of dichloromethane, tetrahydrofuran, acetone, N,N-dimethylformamide, and N-methylpyrrolidone in any proportion; the solvent in the D solution includes: a mixture of one or more of acetone, tetrahydrofuran, methanol, acetonitrile, and N,N-dimethylformamide in any proportion.

8. The method for preparing a high-toughness self-repairing supramolecular polyurethane elastomer based on thiolactone chemistry according to claim 1, characterized in that: The alkaline catalyst includes triethylamine, dimethylphenylphosphine or tributylphosphine; the catalyst includes triethylamine, triethylenediamine, dibutyltin dilaurate or stannous octoate.

9. A high-toughness self-healing supramolecular polyurethane elastomer based on thiolactone chemistry prepared by the method according to any one of claims 1 to 8, characterized in that: A diol chain extender containing a pendant 2-ureido-4[1H]-pyrimidinone (UPy) motif and an imidazole ligand was synthesized via a one-pot, two-step "amine-thiol-acrylate" coupling reaction of thiolactone. The diol chain extender was introduced into polyurethane and cross-linked using metal ions to obtain a supramolecular polyurethane elastomer. Utilizing the dual functionalization of thiolactone, a high-density reversible sacrificial bond was introduced into the polyurethane side chain, resulting in a supramolecular elastomer with both excellent mechanical properties and mild dynamic repair capabilities.

Images