阅读说明：本技术 仿生启发的具有超韧、超拉伸及自修复高回弹性聚氨酯弹性体的制备方法 (Preparation method of bionic inspired high-resilience polyurethane elastomer with super-toughness, super-stretching and self-repairing functions ) 是由 孙平川 黎剑 王粉粉 于 2021-01-21 设计创作，主要内容包括：一种仿生启发的具有超韧、超拉伸及自修复高回弹性聚氨酯弹性体的制备方法,原料包括聚四氢呋喃、1,6-己二异氰酸酯,乙酰丁内酯,碳酸胍,2,6-二氨基吡啶,无水三氯化铁等。制备包括以下步骤：1)合成多重氢键单体；2)含有多重氢键及金属络合键的弹性体制备；本发明的优点在于：聚氨酯弹性体网络中含有大量的多重氢键和金属络合键,因此弹性体具有优异的力学性能：超韧、超拉伸。非共价键的动态可逆性赋予了该弹性体自修复性。该弹性体制备方法简单,原料丰富,与传统的聚氨酯弹性体相比,具有可调控的韧性、拉伸性,及优异的自修复性和高回弹性,在可穿戴,密封垫,热熔胶等领域有潜在的应用价值。(A bionic inspired polyurethane elastomer with super toughness, super stretch and self-repairing high resilience is prepared from polytetrahydrofuran, 1, 6-hexamethylene diisocyanate, acetylbutyrolactone, guanidine carbonate, 2, 6-diaminopyridine, anhydrous ferric chloride, etc. The preparation method comprises the following steps: 1) synthesizing multiple hydrogen bond monomers; 2) preparing an elastomer containing multiple hydrogen bonds and metal complex bonds; the invention has the advantages that: the polyurethane elastomer network contains a large number of multiple hydrogen bonds and metal complex bonds, so that the elastomer has excellent mechanical properties: super-tough and super-tensile. The dynamic reversibility of the non-covalent bond imparts self-healing properties to the elastomer. The elastomer is simple in preparation method and rich in raw materials, has adjustable toughness and stretchability, excellent self-repairability and high resilience compared with the traditional polyurethane elastomer, and has potential application value in the fields of wearability, sealing gaskets, hot melt adhesives and the like.)

1. A preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: dissolving 2-acetylbutyrolactone, guanidine carbonate and triethylamine in a molar ratio of 1:1.1: 2.1-1: 1.2:2.2 in 30-40 ml of absolute ethanol, and carrying out reflux reaction at 95-100 ℃ for 1 hour; the mixture gradually became clear from turbidity and the reaction was continued for 3 hours; after the reaction is finished, filtering the mixed solution to obtain a precipitate, washing the precipitate with ethanol, and finally drying the precipitate in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor;

step 1.2) adding the multiple hydrogen bond precursor obtained by the reaction and 1, 6-Hexamethylene Diisocyanate (HDI) into a 100ml round-bottom flask containing 1ml of pyridine and provided with magnetons according to a molar ratio of 1: 10-1: 11, reacting the mixture solution at 95-100 ℃ for 2 hours under the protection of nitrogen while stirring, cooling to room temperature, washing the reaction mixture with 10 times of petroleum ether to obtain a white precipitate, washing the obtained white precipitate with n-hexane, and finally performing vacuum drying at room temperature to obtain a white powdery solid, namely the multiple hydrogen bond monomer (HDI-UPy-HDI);

step 2) preparation of polyurethane elastomer

Step 2.1) first, the molecular weight M_nDissolving 2000 hydroxyl-terminated polytetrahydrofuran and multiple hydrogen bond monomers in anhydrous N, N-dimethylacetamide, and reacting for 1 hour at 70-75 ℃ under the protection of nitrogen to obtain a prepolymer; then slowly adding 1, 6-hexamethylene diisocyanate into the prepolymer solution, continuing to react for 0.5 hour, finally adding 2, 6-diaminopyridine dissolved in anhydrous N, N-dimethylacetamide and 20mg of catalyst dibutyltin dilaurate into the prepolymer mixed solution, and stirring at 70-75 ℃ for reacting for 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds; the mole ratio of the polytetrahydrofuran, the multiple hydrogen bond monomer, the 1, 6-hexamethylene diisocyanate and the 2, 6-diaminopyridine is as follows: 2:1:2: 1-2: 1.05:2.05: 1.05;

step 2.2) adding ferric trichloride dissolved in N, N-dimethylacetamide to the multiple hydrogen bond crosslinked polyurethane polymer solution obtained by the reaction in the step 2.1), fully stirring to form a uniform solution, finally pouring the solution into a polytetrafluoroethylene casting disc, and then carrying out vacuum drying at 70-75 ℃ for 48 hours to obtain a polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds; the molar ratio of the ferric trichloride to the multiple hydrogen bond crosslinked polyurethane polymer is 1: 2-1.1: 2.

Technical Field

The invention belongs to the field of functional polymer materials, and particularly relates to a preparation method of a super-tough, super-tensile and self-repairing high-resilience polyurethane elastomer.

Background

The polyurethane elastomer is an important functional material, has excellent comprehensive properties such as high strength, high toughness, wear resistance, oil resistance and the like, and is widely applied to various fields of national economy, such as light industry, chemical industry, electronics, textile, medical treatment, building materials, automobiles, national defense and the like. Polyurethane elastomers can be divided into thermoset and thermoplastic elastomers. Thermoset elastomers have a relatively high modulus, but are poorly ductile and non-recyclable. The thermoplastic elastomer has good toughness, but low modulus and poor mechanical property. Although great progress has been made in the development of polyurethane elastomers, it is still difficult to obtain polyurethane elastomers having excellent mechanical properties (high strength, high toughness and hyperextension) combined with excellent self-healing and high resilience.

Recently, the introduction of dynamic noncovalent bonds (such as hydrogen bonds, metal-ligand and ionic interactions, etc.) into polymer networks as sacrificial bonds has received a great deal of attention from the materials scientists. In these materials containing sacrificial bonds, the sacrificial bonds can withstand the load under less deformation and break before covalent bonds in the polymer network, thus dissipating a large amount of energy, thereby improving the mechanical properties of the polymer material. In addition, due to the dynamic reversibility of the sacrificial bond, the polymer material has excellent self-repairing capability and high resilience capability.

Therefore, the dynamic non-covalent bond is introduced into the polyurethane elastomer material, and the development of the elastomer with super toughness, super stretching and high resilience which can be repaired at the same time is of great significance in the functional material with high performance.

Disclosure of Invention

The invention aims to solve the problems of low mechanical strength, irreparability and low rebound resilience of the existing polyurethane elastomer, and provides a preparation method of a high-resilience elastomer with super toughness, super stretching and repairable simultaneously.

The method is inspired by the multilevel structure of the titin and marine mussels of the biological tissues in nature, and multiple hydrogen bonds and metal complex bonds are simultaneously introduced into a linear polyurethane main chain, so that the mechanical property of the polyurethane elastomer is enhanced. Firstly, the dimerization function of multiple hydrogen bonds can be used as a physical crosslinking point of a polymer network, and the continuous dissociation and combination of dimers enable the elastomer to have rich load dispersion points in the stretching process, so that the toughness of the elastomer is obviously improved. Secondly, the ability of the complex bond formed between the metal ion and the coordination compound in the polymer to reversibly break and bond gives the elastomer excellent energy dissipation during stretching, thereby again improving the strength and toughness of the material. Finally, elastomers exhibit excellent self-healing and high resilience based on the synergistic dynamic reversible properties of multiple hydrogen bonds and metal complex bonds.

The technical scheme of the invention is as follows:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: dissolving 2-acetylbutyrolactone, guanidine carbonate and triethylamine in a molar ratio of 1:1.1: 2.1-1: 1.2:2.2 in 40ml of absolute ethanol, and carrying out reflux reaction at 95-100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) adding the multiple hydrogen bond precursor obtained by the reaction and 1, 6-Hexamethylene Diisocyanate (HDI) into a 100ml round-bottom flask containing 1ml of pyridine and provided with magnetons according to a molar ratio of 1: 10-1: 11, reacting the mixture solution at 95-100 ℃ for 2 hours under the protection of nitrogen by stirring, cooling to room temperature, washing the reaction mixture by 10 times of petroleum ether to generate white precipitate, washing the obtained white precipitate with n-hexane for three times, and finally drying in vacuum at room temperature to obtain white powdery solid, namely the multiple hydrogen bond monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, the molecular weight M_nDissolving 2000 hydroxyl-terminated polytetrahydrofuran and multiple hydrogen bond monomers in anhydrous N, N-dimethylacetamide, and reacting for 1 hour at 70-75 ℃ under the protection of nitrogen to obtain a prepolymer. Subsequently, 1, 6-hexamethylene diisocyanate was slowly added to the above prepolymer solution, and the reaction was continued for 0.5 hour. And finally, adding 2, 6-diaminopyridine dissolved in anhydrous N, N-dimethylacetamide and 20mg of dibutyltin dilaurate serving as a catalyst into the prepolymer mixed solution, and stirring and reacting at 70-75 ℃ for 12 hours to obtain the polyurethane polymer solution containing multiple hydrogen bonds. The mole ratio of the polytetrahydrofuran, the multiple hydrogen bond monomer, the 1, 6-hexamethylene diisocyanate and the 2, 6-diaminopyridine is as follows: 2:1:2: 1-2: 1.05:2.05: 1.05.

And 2.2) adding ferric trichloride dissolved in N, N-dimethylacetamide to the multiple hydrogen bond crosslinked polyurethane polymer solution obtained by the reaction in the step 2.1), fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70-75 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds. The molar ratio of the ferric trichloride to the multiple hydrogen bond crosslinked polyurethane polymer is 1: 2-1.1: 2.

The method for detecting the performance of the prepared bionic polyurethane elastomer comprises the following steps:

1) nuclear magnetic resonance spectroscopy (NMR), liquid NMR experiments were performed on a BrukerAVANCE model iii liquid nuclear magnetic spectrometer with a proton nuclear magnetic resonance frequency of 399.72 MHz. The test temperature was 25 ℃ and the sample was dissolved in d₆NMR tests in DMSO solvents.

2) Standard tensile test, the mechanical properties of the polyurethane material were investigated by the Standard tensile test using a UTM6103 type stretcher (Shenzhen Sansi longitudinal and transverse science and technology Co., Ltd., China). The sample was cut into a dumbbell-shaped specimen having a length of 3cm and a width of 5mm, and the specimen was stretched at a speed of 100mm/min by means of a universal tensile machine, and the maximum load and the elongation at break were recorded. The tensile strength was calculated according to the formula σ ═ F/S. σ is tensile strength (Pa), F is maximum load before breaking in tensile test (unit: N), and s is elastomer cross-sectional area (unit: mm)²) Wherein toughness is defined as the area of the stress-strain curve (unit: MJ/m)³)。

3) And (4) performing a resilience test, controlling the strain to be 500%, and performing a cyclic loading-unloading test at a tensile rate of 100 mm/min. To ensure data accuracy, each set of samples was tested at least 3 times and the results averaged.

4) And (4) self-repairing performance testing, namely completely cutting off the dumbbell-shaped sample strips from the middle, fully contacting the cut samples with each other, fully self-repairing the cut samples in a 100-DEG C oven, and performing tensile testing on the repaired sample strips at the tensile rate of 100 mm/min. To ensure data accuracy, each set of samples was tested at least 3 times and the results averaged.

The invention has the advantages and beneficial effects that:

the polyurethane elastomer network prepared by the invention contains a large amount of multiple hydrogen bond interaction and metal complexing interaction, and has an excellent energy dissipation mechanism, so that the elastomer has excellent mechanical properties: namely, the elastomer has super toughness, super elongation, excellent self-repairability and high resilience, and the elastomer is endowed with self-repairability and reworkability by the dynamic reversibility of non-covalent bonds. The elastomer is simple in preparation method and rich in raw materials, has adjustable and controllable toughness and stretchability, excellent self-repairability, high resilience and other properties compared with the traditional polyurethane elastomer, and has wide application value and application prospect in the fields of wearability, sealing gaskets, hot melt adhesives and the like.

Drawings

FIG. 1 is a liquid NMR hydrogen spectrum of a synthesized multiple hydrogen bonding monomer (HDI-UPy-HDI).

FIG. 2 is a mechanical property test of polyurethane elasticity. Wherein, the graph a is a polyurethane elastomer mechanical property curve containing different multiple hydrogen bonds and metal complex bonds, and the graph b is a summary comparison of the toughness of the polyurethane elastomer containing different multiple hydrogen bonds and metal complex bonds.

FIG. 3 is a rebound resilience test of a polyurethane elastomer. Wherein, the graph a is the recovery curve of the stress-strain curve with time when the polyurethane is stretched to 500% strain, and the graph b is the change of the strain and rebound resilience of the polyurethane elastomer after stretching with time.

Figure 4 self-healing testing of polyurethane elastomers. Wherein, the figure a is a drawing chart of a 2.5Kg weight which can be lifted by the polyurethane elastomer after the polyurethane elastomer is self-repaired, and the figure b is a drawing curve chart of the polyurethane elastomer after the polyurethane elastomer is self-repaired.

Detailed Description

Example 1:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.6g of guanidine carbonate and 11ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 14ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 100 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_n2000 of hydroxyl terminated polytetrahydrofuran with 1.010g of multiple hydrogen bonding monomer dissolved in 15ml of anhydrous N, NDimethylacetamide and reacted at 70 ℃ under nitrogen for 1 hour to obtain a prepolymer. Subsequently, 0.672g of hexamethylene 1, 6-diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.216g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 70 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.162g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

Example 2:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.6g of guanidine carbonate and 11ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 95 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 14ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 95 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_nHydroxyl-terminated polytetrahydrofuran of 2000 g was dissolved with 1.010g of multiple hydrogen bond monomer in 15ml of anhydrous N, N-dimethylacetamide and reacted under nitrogen protection at 70 ℃ for 1 hour to give a prepolymer. Subsequently, 0.672g of hexamethylene 1, 6-diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.216g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 70 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.162g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

Example 3:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.6g of guanidine carbonate and 11ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 14ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 100 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_nHydroxyl-terminated polytetrahydrofuran of 2000 g was dissolved with 1.010g of multiple hydrogen bond monomer in 15ml of anhydrous N, N-dimethylacetamide and reacted under nitrogen protection at 75 ℃ for 1 hour to give a prepolymer. Subsequently, 0.672g of hexamethylene 1, 6-diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.216g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 75 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.162g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 75 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

Example 4:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.8g of guanidine carbonate and 12ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 14ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 100 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_nHydroxyl-terminated polytetrahydrofuran of 2000 g was dissolved with 1.010g of multiple hydrogen bond monomer in 15ml of anhydrous N, N-dimethylacetamide and reacted under nitrogen protection at 70 ℃ for 1 hour to give a prepolymer. Subsequently, 0.672g of hexamethylene 1, 6-diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.216g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 70 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.162g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

Example 5:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.6g of guanidine carbonate and 11ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 16ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 100 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_nHydroxyl-terminated polytetrahydrofuran of 2000 g was dissolved with 1.010g of multiple hydrogen bond monomer in 15ml of anhydrous N, N-dimethylacetamide and reacted under nitrogen protection at 70 ℃ for 1 hour to give a prepolymer. Subsequently, 0.672g of hexamethylene 1, 6-diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.216g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 70 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.162g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

Example 6:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.6g of guanidine carbonate and 11ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 14ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 100 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_nHydroxyl-terminated polytetrahydrofuran of 2000 g was dissolved with 1.06g of multiple hydrogen bond monomers in 15ml of anhydrous N, N-dimethylacetamide and reacted under nitrogen protection at 70 ℃ for 1 hour to give a prepolymer. Subsequently, 0.688g of 1, 6-Hexamethylene Diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.223g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 70 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.162g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

Example 7:

a preparation method of a bionic inspired high-resilience polyurethane elastomer with super toughness, super stretching and self-repairing comprises the following steps:

step 1) Synthesis of multiple Hydrogen bond monomer (HDI-UPy-HDI)

Step 1.1) synthesis of multiple hydrogen bond precursors: 5.12g of 2-acetylbutyrolactone, 3.6g of guanidine carbonate and 11ml of triethylamine were dissolved in 40ml of anhydrous ethanol, and the reaction was refluxed at 100 ℃ for 1 hour. The mixture gradually became clear from turbidity and the reaction was continued for 3 hours. After the reaction is finished, the mixed solution is filtered to obtain a precipitate, the precipitate is washed with ethanol for three times, and finally the precipitate is dried in a vacuum drying oven at room temperature for 24 hours to obtain white powder solid, namely the multiple hydrogen bond precursor.

Step 1.2) to a 100ml round-bottom flask equipped with magnetons were added 0.85g of the precursor obtained by the above reaction and 14ml of 1, 6-Hexamethylene Diisocyanate (HDI) and 1ml of pyridine, respectively, the mixture solution was reacted at 100 ℃ for 2 hours with stirring under nitrogen protection, followed by cooling to room temperature, the reaction mixture was washed with 10-fold volume of petroleum ether, a white precipitate appeared, the obtained white precipitate was washed three times with n-hexane, and finally vacuum-dried at room temperature to obtain a white powdery solid multiple hydrogen bonding monomer (HDI-UPy-HDI).

Step 2) preparation of polyurethane elastomer

Step 2.1) first, 8.0g of molecular weight M_nHydroxyl-terminated polytetrahydrofuran of 2000 g was dissolved with 1.010g of multiple hydrogen bond monomer in 15ml of anhydrous N, N-dimethylacetamide and reacted under nitrogen protection at 70 ℃ for 1 hour to give a prepolymer. Subsequently, 0.672g of hexamethylene 1, 6-diisocyanate (HDI) was slowly poured into the above prepolymer solution, and the reaction was continued for 0.5 hour. Finally, 0.216g of 2, 6-diaminopyridine and 20mg of the catalyst dibutyltin dilaurate were dissolved in 10ml of anhydrous N, N-dimethylacetamide, added to the above mixture, and stirred at 70 ℃ for another 12 hours to obtain a polyurethane polymer solution containing multiple hydrogen bonds.

And 2.2) dissolving 0.178g of anhydrous ferric trichloride in 5ml of N, N-dimethylacetamide, adding the anhydrous ferric trichloride into the multiple hydrogen bond crosslinking polyurethane polymer solution obtained by the reaction, fully stirring to form a uniform solution, pouring the uniform solution into a polytetrafluoroethylene casting disc, and then performing vacuum drying at 70 ℃ for 48 hours to obtain the polyurethane elastomer film containing multiple hydrogen bonds and metal complex bonds.

The detection method of the prepared bionic polyurethane elastomer comprises the following steps:

1) liquid nuclear magnetic resonance hydrogen spectrum detection of multiple hydrogen bond monomer (HDI-UPy-HDI)

Liquid NMR experiments were carried out on a Bruker AVANCE model III liquid nuclear magnetic spectrometer with a proton nuclear magnetic resonance frequency of 399.72 MHz. The test temperature was 25 ℃ and the sample was dissolved in d₆NMR tests in DMSO solvents. The results of the tests are shown in FIG. 1, and the results of the tests are 1H Chemical Shift delta (ppm):12.93(S,1H),11.90(S,1H),10.12(S,1H),4.65(S,1H),4.18(t, J ═ 6.4Hz,2H),3.29(t, J ═ 6.4Hz,4H),3.25(m,2H),3.15(m,2H),2.76(t, J ═ 6.0Hz,2H),2.27(S,3H),1.6-1.3(m,16H), indicating the successful synthesis of multiple hydrogen bond monomers.

2) Mechanical detection of polyurethane elastomer

The mechanical properties of the polyurethane materials were studied by a standard tensile test using a UTM6103 tensile machine (Shenzhen san Si longitudinal and transverse science, Inc., China). The sample was cut into a dumbbell-shaped specimen having a length of 3cm and a width of 5mm, and the specimen was stretched at a speed of 100mm/min by means of a universal tensile machine, and the maximum load and the elongation at break were recorded. The tensile strength was calculated according to the formula σ ═ F/S. σ is tensile strength (Pa), F is maximum load before breaking in tensile test (unit: N), and s is elastomer cross-sectional area (unit: mm)²) Wherein toughness is defined as the area of the stress-strain curve (unit: MJ/m)³). The detection results are shown in FIG. 2, in which: the figure a shows the mechanical property curve of the polyurethane elastomer containing different multiple hydrogen bonds and metal complex bonds, and the figure b shows the summary comparison of the toughness of the polyurethane elastomer containing different multiple hydrogen bonds and metal complex bonds. From the results, it can be seen that the polyurethane elastomer containing dual dynamic non-covalent bonds exhibits excellent mechanical properties, tensile strength: 30MPa, elongation at breakThe length rate is as follows: 4100%, toughness: 470MJ/m³。

3) Rebound resilience test of polyurethane elastomer

The strain is controlled to be 500%, the stretching speed is 100mm/min, and the cyclic loading-unloading test is carried out. The results of the tests are shown in FIG. 3, in which: FIG. a is a recovery curve of a stress-strain curve when the polyurethane is stretched to 500% strain, and FIG. b is a change with time of strain and rebound after the polyurethane elastomer is stretched. As can be seen from the results, the polyurethane elastomer has excellent resilience, and the resilience gradually increases with time when stretched to 500% strain, and it can be recovered to 82% after 4 hours.

4) Polyurethane elastomer self-repair detection

The dumbbell-shaped sample bars are completely cut off from the middle, then the cut samples are fully contacted with each other, the sample bars are placed in an oven at 100 ℃ for full self-repairing, the repaired sample bars are subjected to a tensile test, and the tensile rate is 100 mm/min. The detection result is shown in fig. 4, in which a is a graph showing that a weight of 2.5Kg can be lifted by the self-repairing polyurethane elastomer, and b is a graph showing the tensile curve of the self-repairing polyurethane elastomer. From the results, it can be seen that the polyurethane elastomer exhibits excellent self-healing properties due to the dynamic reversibility of the non-covalent bond.