阅读说明：本技术 一种自修复聚氨酯材料及其制备方法 (Self-repairing polyurethane material and preparation method thereof ) 是由 邓煜东 闫磊 于 2021-10-09 设计创作，主要内容包括：本申请属于聚氨酯材料领域,提供了一种自修复聚氨酯材料及其制备方法。本申请采用分步制备的方法,先得到含二硫键大分子二元醇,再以含二硫键大分子二元醇为原料制备含二硫键的聚氨酯溶液,同时以常规大分子二元醇为原料制备硬段聚氨酯溶液,最后将两种聚氨酯溶液按照一定比例混合浇注得到力学性优秀的自修复聚氨酯材料。本申请提供的自修复聚氨酯材料能够应用于柔性电子器件,对建设资源节约型和环境友好性社会以及人类可持续发展具有重要意义。(The application belongs to the field of polyurethane materials, and provides a self-repairing polyurethane material and a preparation method thereof. The self-repairing polyurethane material with excellent mechanical property is prepared by adopting a stepwise preparation method, firstly obtaining the disulfide bond-containing macrodiol, then preparing the disulfide bond-containing polyurethane solution by taking the disulfide bond-containing macrodiol as a raw material, simultaneously preparing the hard-segment polyurethane solution by taking the conventional macrodiol as a raw material, and finally mixing and pouring the two polyurethane solutions according to a certain proportion. The self-repairing polyurethane material provided by the application can be applied to flexible electronic devices, and has important significance for building resource-saving and environment-friendly society and human sustainable development.)

1. The preparation method of the self-repairing polyurethane material is characterized by comprising the following steps of:

(1.1) mixing a cyclic ester monomer, a dihydroxy disulfide and a catalyst in a protective atmosphere, and then reacting to obtain a disulfide bond-containing macrodiol;

(1.2) under a protective atmosphere, mixing the disulfide bond-containing macromolecular diol, a diisocyanate compound, a catalyst and a solvent, and then reacting to obtain a prepolymer solution a;

(1.3) adding a chain extender into the prepolymer solution a to continue reacting to obtain a polyurethane solution containing a disulfide bond;

(2.1) mixing macromolecular diol, a solvent, a diisocyanate compound and a catalyst in a protective atmosphere, and then reacting to obtain a prepolymer solution b;

(2.2) adding a chain extender into the prepolymer solution b to continue reacting to obtain a hard segment polyurethane solution;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material.

2. The preparation method of the self-repairing polyurethane material according to claim 1, wherein in the step (1.1), the reaction temperature is 100-140 ℃, and the reaction time is 5-7 h;

the cyclic ester monomer is one or two of caprolactone, lactide, valerolactone and tetrahydrofuran;

the dihydroxy disulfide compound is one or two of disulfide diethanol and disulfide dipropanol;

the catalyst is one or more of zinc acetate, tin isooctanoate, aluminium isopropoxide and tin tetrachloride;

the using amount of the dihydroxy disulfide is 0.2-0.4% of the mass of the cyclic ester monomer;

the dosage of the catalyst is 0.01-0.2% of the mass of the cyclic ester monomer;

the molecular weight of the disulfide bond-containing macrodiol is 1000-7000.

3. The preparation method of the self-repairing polyurethane material of claim 2, wherein the reaction in the step (1.2) is carried out under stirring conditions, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 1-2 h;

the catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether, N-ethyl morpholine and triethylene diamine;

the solvent is one or more of ethyl acetate, acetone, tetrahydrofuran, N-dimethylacetamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform;

the diisocyanate compound is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, xylylene diisocyanate and naphthalene diisocyanate;

the amount of the catalyst is 0.01-0.2% of the mass of the diisocyanate compound;

the mass molar ratio of the solvent to the diisocyanate compound is 7.6-7.8 g: 3-3.5 mmol.

4. The preparation method of the self-repairing polyurethane material according to the claim 2 or 3, characterized in that the reaction in the step (1.3) is carried out under stirring conditions, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 2-3 h;

the chain extender is one or more of 1, 4-butanediol, 1, 6-hexanediol, 1, 2-ethylene glycol and 1, 3-propylene glycol;

the molar ratio of the cyclic ester monomer to the diisocyanate compound to the chain extender is 2-2.5: 3-3.5: 1.3-1.35.

5. The preparation method of the self-repairing polyurethane material of claim 4, wherein the reaction in the step (2.1) is carried out under stirring conditions, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 1-2 h;

the macromolecular dihydric alcohol is one or two of polytetrahydrofuran, polyethylene glycol and polypropylene glycol;

the molecular weight of the macromolecular dihydric alcohol is 1000-3000;

the catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether, N-ethyl morpholine and triethylene diamine;

the solvent is one or more of ethyl acetate, acetone, tetrahydrofuran, N-dimethylacetamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform;

the diisocyanate compound is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, xylylene diisocyanate and naphthalene diisocyanate;

the dosage of the catalyst is 0.01-0.2% of the mass of the macromolecular dihydric alcohol;

the mass molar ratio of the solvent to the diisocyanate compound is 5.3-5.5 g: 3-3.5 mmol.

6. The preparation method of the self-repairing polyurethane material of claim 5, wherein the reaction in the step (2.2) is carried out under stirring conditions, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 2-3 h;

the chain extender is one or more of 1, 4-butanediol, 1, 6-hexanediol, 1, 2-ethylene glycol and 1, 3-propylene glycol;

the molar ratio of the macromolecular diol to the diisocyanate compound to the chain extender is 0.7-0.8: 3-3.5: 6.64-6.69.

7. The preparation method of the self-repairing polyurethane material as claimed in claims 1-6, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution in the step (3) is as follows: (0.25-2) 1.

8. The preparation method of the self-repairing polyurethane material of claim 7, wherein the temperature of the first drying treatment in the step (3) is 70-90 ℃, and the treatment time is 17-18 h;

the temperature of the second drying treatment is 110-130 ℃, and the treatment time is 4-5 h.

9. The self-repairing polyurethane material prepared by the preparation method of the self-repairing polyurethane material of any one of claims 1 to 8.

Technical Field

The application relates to the field of polyurethane materials, in particular to a self-repairing polyurethane material and a preparation method thereof.

Background

The polyurethane material has good flexibility and elasticity, so that the polyurethane material can be used for high-value-added industrial products such as flexible electronic devices, biomedical equipment and the like, and has an important function.

Polyurethane is a material having good elasticity like rubber. This class of materials generally exhibits thermosetting properties, i.e., they do not have the ability to dissolve in a solvent after becoming solid and the ability to be processed with the application of a certain amount of pressure. In daily life, the polyurethane material is inevitably physically damaged due to some factors, so that the damaged part is easily torn or permanently fails, and finally, the availability of the polyurethane material is reduced, the service life is shortened, the maintenance cost is increased, and other problems are caused. This not only causes a great waste of resources, but also causes a serious pollution to the environment. Therefore, the preparation of the recyclable polyurethane material with tear resistance and self-repairing capability is very important, so that the service life and the recycling capability of the polyurethane material can be obviously improved, and the preparation method has very important significance for building a resource-saving and environment-friendly society and realizing sustainable development of human beings.

The self-repairing polymers mainly comprise two main types, namely extrinsic self-repairing polymers and intrinsic self-repairing polymers. The extrinsic self-repairing polymer is prepared by wrapping a material with repairing capacity in microcapsules and mixing the material into a polymer matrix, and when the polyurethane material is damaged by the outside, the microcapsules in the polymer matrix are broken to cause the material with repairing capacity to flow out, so that the repairing purpose is achieved.

Intrinsic self-repairing polymers mainly rely on the reconstruction of dynamic bonds in polymer chains to complete self-repairing. When the material is damaged, the dynamic bonds in the molecular chain are reconnected to complete self-repairing, so that the intrinsic self-repairing polymer has the advantage of being capable of self-repairing for many times.

However, how to prepare a polyurethane material with good mechanical properties and high self-repairing efficiency becomes a technical problem to be solved at present.

Disclosure of Invention

In view of the above, one of the objectives of the present application is to provide a method for preparing a self-repairing polyurethane material, comprising the following steps:

(1.1) mixing a cyclic ester monomer, a dihydroxy disulfide and a catalyst in a protective atmosphere, and then reacting to obtain a disulfide bond-containing macrodiol;

(1.2) under a protective atmosphere, mixing the disulfide bond-containing macromolecular diol, a diisocyanate compound, a catalyst and a solvent, and then reacting to obtain a prepolymer solution a;

(1.3) adding a chain extender into the prepolymer solution a to continue reacting to obtain a polyurethane solution containing a disulfide bond;

(2.1) mixing macromolecular diol, a solvent, a diisocyanate compound and a catalyst in a protective atmosphere, and then reacting to obtain a prepolymer solution b;

(2.2) adding a chain extender into the prepolymer solution b to continue reacting to obtain a hard segment polyurethane solution;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material.

Further, in step (1.1):

the reaction temperature is 100-140 ℃, and the reaction time is 5-7 h;

the cyclic ester monomer is one or two of caprolactone, lactide, valerolactone and tetrahydrofuran;

the dihydroxy disulfide compound is one or two of disulfide diethanol and disulfide dipropanol;

the catalyst is one or more of zinc acetate, tin isooctanoate, aluminium isopropoxide and tin tetrachloride;

the using amount of the dihydroxy disulfide is 0.2-0.4% of the mass of the cyclic ester monomer;

the dosage of the catalyst is 0.01-0.2% of the mass of the cyclic ester monomer;

the molecular weight of the disulfide bond-containing macrodiol is 1000-7000.

Further, in step (1.2):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 1-2 h;

the catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether, N-ethyl morpholine and triethylene diamine;

the solvent is one or more of ethyl acetate, acetone, tetrahydrofuran, N-dimethylacetamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform;

the diisocyanate compound is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, xylylene diisocyanate and naphthalene diisocyanate;

the amount of the catalyst is 0.01-0.2% of the mass of the diisocyanate compound;

the mass molar ratio of the solvent to the diisocyanate compound is 7.6-7.8 g: 3-3.5 mmol.

Further, in step (1.3):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 2-3 h;

the chain extender is one or more of 1, 4-butanediol, 1, 6-hexanediol, 1, 2-ethylene glycol and 1, 3-propylene glycol;

the molar ratio of the cyclic ester monomer to the diisocyanate compound to the chain extender is 2-2.5: 3-3.5: 1.3-1.35.

Further, in step (2.1):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 1-2 h;

the macromolecular dihydric alcohol is one or two of polytetrahydrofuran, polyethylene glycol and polypropylene glycol;

the molecular weight of the macromolecular dihydric alcohol is 1000-3000;

the catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether, N-ethyl morpholine and triethylene diamine;

the solvent is one or more of ethyl acetate, acetone, tetrahydrofuran, N-dimethylacetamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform;

the diisocyanate compound is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, xylylene diisocyanate and naphthalene diisocyanate;

the dosage of the catalyst is 0.01-0.2% of the mass of the macromolecular dihydric alcohol;

the mass molar ratio of the solvent to the diisocyanate compound is 5.3-5.5 g: 3-3.5 mmol.

Further, in step (2.2):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 2-3 h;

the chain extender is one or more of 1, 4-butanediol, 1, 6-hexanediol, 1, 2-ethylene glycol and 1, 3-propylene glycol;

the molar ratio of the macromolecular diol to the diisocyanate compound to the chain extender is 0.7-0.8: 3-3.5: 6.64-6.69.

Further, in step (3):

the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is as follows: (0.25-2) 1.

The temperature of the first drying treatment is 70-90 ℃, and the treatment time is 17-18 h;

the temperature of the second drying treatment is 110-130 ℃, and the treatment time is 4-5 h.

Another object of the present application is to provide a self-repairing polyurethane material obtained by the above preparation method.

The beneficial effect of this application is as follows:

1. according to the application, the disulfide bond is locked in the soft segment crystalline phase of polyurethane through the crystalline region phase lock, so that the toughness and the fracture energy of the polyurethane elastomer are further improved in deformation, and the appropriate hard segment content provides mechanical property, so that the material has excellent toughness and high fracture energy.

2. The self-repairing polyurethane material provided by the application can realize excellent self-repairing capability without any auxiliary means under a mild condition.

3. The self-repairing polyurethane material provided by the application can be applied to flexible electronic devices, and has important significance for building resource-saving and environment-friendly society and human sustainable development.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a DSC of self-repairing polyurethane materials prepared in examples 1,2 and 3 of the present application;

FIG. 2 is a tensile diagram of a stress-strain curve of a self-repairing polyurethane material prepared in examples 1,2 and 3 of the present application;

fig. 3 is a photograph of a self-repairing process of the self-repairing polyurethane material prepared in example 2 of the present application under an electron microscope.

Detailed Description

A preparation method of a self-repairing polyurethane material comprises the following steps:

(1.1) mixing a cyclic ester monomer, a dihydroxy disulfide and a catalyst in a protective atmosphere, and then reacting to obtain a disulfide bond-containing macrodiol;

(1.2) under a protective atmosphere, mixing the disulfide bond-containing macromolecular diol, a diisocyanate compound, a catalyst and a solvent, and then reacting to obtain a prepolymer solution a;

(1.3) adding a chain extender into the prepolymer solution a to continue reacting to obtain a polyurethane solution containing a disulfide bond;

(2.1) mixing macromolecular diol, a solvent, a diisocyanate compound and a catalyst in a protective atmosphere, and then reacting to obtain a prepolymer solution b;

(2.2) adding a chain extender into the prepolymer solution b to continue reacting to obtain a hard segment polyurethane solution;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material.

Further, in step (1.1):

the reaction temperature is 100-140 ℃, and the reaction time is 5-7 h;

preferably, the reaction temperature is 120-130 ℃, and the reaction time is 6 h.

The cyclic ester monomer is one or two of caprolactone, lactide, valerolactone and tetrahydrofuran;

the dihydroxy disulfide compound is one or two of disulfide diethanol and disulfide dipropanol;

the catalyst is one or more of zinc acetate, tin isooctanoate, aluminium isopropoxide and tin tetrachloride;

the using amount of the dihydroxy disulfide is 0.2-0.4% of the mass of the cyclic ester monomer;

preferably, the amount of dihydroxy disulfide used is 0.3% by mass of the cyclic ester monomer.

The dosage of the catalyst is 0.01-0.2% of the mass of the cyclic ester monomer;

preferably, the amount of the catalyst is 0.02-0.1% of the mass of the cyclic ester monomer.

The molecular weight of the disulfide bond-containing macrodiol is 1000-7000;

preferably, the molecular weight of the prepared disulfide bond-containing macrodiol is 2000-5000.

Further, in step (1.2):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 1-2 h;

the stirring speed is 200r/min, the reaction temperature is 75 ℃, and the reaction time is 1.5 h.

The catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether and N-ethyl morpholine triethylene diamine;

the solvent is one or more of ethyl acetate, acetone, tetrahydrofuran, N-dimethylacetamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform;

the diisocyanate compound is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, xylylene diisocyanate and naphthalene diisocyanate;

the amount of the catalyst is 0.01-0.2% of the mass of the diisocyanate compound;

preferably, the amount of the catalyst is 0.02 to 0.1% by mass of the diisocyanate compound.

The mass molar ratio of the solvent to the diisocyanate compound is 7.6-7.8 g: 3-3.5 mmol;

preferably, the mass molar ratio of the solvent to the diisocyanate compound is 7.74g:3.5 mmol;

the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the disulfide bond-containing macrodiol and the chain extender is (1-2.2): 1

Preferably, the molar ratio of isocyanate groups to the total number of disulfide bond-containing macrodiols and hydroxyl groups contained in the chain extension is 1.1: 1.

further, in step (1.3):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 2-3 h;

preferably, the stirring speed is 200r/min, the reaction temperature is 75 ℃, and the reaction time is 2.5 h.

The chain extender is one or more of 1, 4-butanediol, 1, 6-hexanediol, 1, 2-ethylene glycol and 1, 3-propylene glycol;

the molar ratio of the cyclic ester monomer to the diisocyanate compound to the chain extender is 2-2.5: 3-3.5: 1.3-1.35;

preferably, the molar ratio of the cyclic ester monomer, the diisocyanate compound and the chain extender is 2.5:3.5: 1.35.

Further, in step (2.1):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 1-2 h;

preferably, the stirring speed is 200r/min, the reaction temperature is 75 ℃, and the reaction time is 1.5 h.

The macromolecular dihydric alcohol is one or two of polytetrahydrofuran, polyethylene glycol and polypropylene glycol;

the molecular weight of the macromolecular dihydric alcohol is 1000-3000;

preferably, the molecular weight of the macrodiol is 1500-2000.

The catalyst is one or more of dibutyltin dilaurate, stannous octoate, triethylamine, bis-dimethylaminoethyl ether and N-ethyl morpholine triethylene diamine;

the solvent is one or more of ethyl acetate, acetone, tetrahydrofuran, N-dimethylacetamide, 1, 4-dioxane, toluene, butanone, dichloromethane and chloroform;

the diisocyanate compound is one or more of isophorone diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, xylylene diisocyanate and naphthalene diisocyanate;

the dosage of the catalyst is 0.01-0.2% of the mass of the macromolecular dihydric alcohol;

preferably, the amount of the catalyst is 0.02-0.1% of the mass of the macrodiol.

The mass molar ratio of the solvent to the diisocyanate compound is 5.3-5.5 g: 3-3.5 mmol;

preferably, the mass molar ratio of the solvent to the diisocyanate compound is 5.4g:3.5 mmol.

Further, in step (2.2):

the reaction is carried out under the stirring condition, the stirring speed is 150-250 r/min, the reaction temperature is 60-90 ℃, and the reaction time is 2-3 h;

preferably, the stirring speed is 200r/min, the reaction temperature is 75 ℃, and the reaction time is 2.5 h.

The chain extender is one or more of 1, 4-butanediol, 1, 6-hexanediol, 1, 2-ethylene glycol and 1, 3-propylene glycol;

the molar ratio of the macromolecular diol to the diisocyanate compound to the chain extender is 0.7-0.8: 3-3.5: 6.64-6.69;

preferably, the molar ratio of the macromolecular diol to the diisocyanate compound to the chain extender is 0.75:3.5: 6.69.

The molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the macrodiol and the chain extender is (1-2.2) to 1;

preferably, the molar ratio of isocyanate groups to the total number of hydroxyl groups contained in the macrodiol and chain extender is 1.1: 1.

Further, in step (3):

the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is as follows: (0.25-2) 1;

preferably, the mass ratio of the polyurethane solution containing disulfide bonds to the polyurethane solution of the hard segment is 0.75:1, 1:1, 1.25: 1.

The temperature of the first drying treatment is 70-90 ℃, and the treatment time is 17-18 h;

preferably, the temperature of the first drying treatment is 80 ℃, and the treatment time is 18 h.

The temperature of the second drying treatment is 110-130 ℃, and the treatment time is 4-5 h;

preferably, the temperature of the second drying treatment is 120 ℃, and the treatment time is 5 h.

The technical solutions in the embodiments of the present application will be described clearly and completely below, and it should be understood that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Example 1

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing caprolactone, dithiodiethanol and zinc acetate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain the macromolecular dihydric alcohol containing the disulfide bond, wherein the using amount of the dithiodiethanol is 0.3% of the mass of the caprolactone, the using amount of the zinc acetate is 0.02% of the mass of the caprolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing the disulfide bond is 2000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with dicyclohexyl methane diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and reacting for 1.5 hours at 75 ℃ under 200r/min and under the protection of nitrogen to obtain a prepolymer solution a, wherein the using amount of dibutyltin dilaurate is 0.02% of the mass of dicyclohexyl methane diisocyanate, the mass molar ratio of N, N-dimethylacetamide to dicyclohexyl methane diisocyanate is 7.74g:3.5mmol, and the molar ratio of isocyanate groups to the total number of hydroxyl groups of the macromolecular diol containing the disulfide bond and 1, 6-hexanediol is 1.1: 1;

(1.3) adding 1, 6-hexanediol into the prepolymer solution a, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of caprolactone to dicyclohexylmethane diisocyanate to 1, 6-hexanediol is 2.5:3.5: 1.35;

(2.1) mixing polytetrahydrofuran with dicyclohexylmethane diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and reacting for 1.5 hours at 75 ℃ under the protection of nitrogen at 200r/min to obtain a prepolymer solution b, wherein the molecular weight of the polytetrahydrofuran is 2000, the using amount of the dibutyltin dilaurate is 0.02% of the mass of the polytetrahydrofuran, and the mass molar ratio of the N, N-dimethylacetamide to the dicyclohexylmethane diisocyanate is 5.4g:3.5 mmol;

(2.2) adding 1, 6-hexanediol into the prepolymer solution b, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of polytetrahydrofuran, dicyclohexylmethane diisocyanate and 1, 6-hexanediol is 0.75:3.5:6.69, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in polytetrahydrofuran and 1, 6-hexanediol is 1.1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 0.75:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 1.5 MPa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 1 MPa.

Example 2

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing caprolactone, dithiodiethanol and zinc acetate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain the macromolecular dihydric alcohol containing the disulfide bond, wherein the using amount of the dithiodiethanol is 0.3% of the mass of the caprolactone, the using amount of the zinc acetate is 0.02% of the mass of the caprolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing the disulfide bond is 2000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with dicyclohexylmethane diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and reacting for 1.5 hours at 75 ℃, 200r/min and under the protection of nitrogen to obtain a prepolymer solution a, wherein the using amount of dibutyltin dilaurate is 0.02% of the mass of dicyclohexylmethane diisocyanate, and the mass molar ratio of N, N-dimethylacetamide to dicyclohexylmethane diisocyanate is 7.74g:3.5 mol, wherein the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the disulfide bond-containing macrodiol and the chain extender is 1.1: 1;

(1.3) adding 1, 6-hexanediol into the prepolymer solution a, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of caprolactone to dicyclohexylmethane diisocyanate to 1, 6-hexanediol is 2.5:3.5: 1.35;

(2.1) mixing polytetrahydrofuran with dicyclohexylmethane diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and reacting for 1.5 hours at 75 ℃ under the protection of nitrogen at 200r/min to obtain a prepolymer solution b, wherein the molecular weight of the polytetrahydrofuran is 2000, the using amount of the dibutyltin dilaurate is 0.02% of the mass of the polytetrahydrofuran, and the mass molar ratio of the N, N-dimethylacetamide to the dicyclohexylmethane diisocyanate is 5.4g:3.5 mmol;

(2.2) adding 1, 6-hexanediol into the prepolymer solution b, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of polytetrahydrofuran, dicyclohexylmethane diisocyanate and 1, 6-hexanediol is 0.75:3.5:6.69, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in polytetrahydrofuran and 1, 6-hexanediol is 1.1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 1:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 7.5 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 6.7 MPa.

Example 3

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing caprolactone, dithiodiethanol and zinc acetate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain the macromolecular dihydric alcohol containing the disulfide bond, wherein the using amount of the dithiodiethanol is 0.3% of the mass of the caprolactone, the using amount of the zinc acetate is 0.02% of the mass of the caprolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing the disulfide bond is 2000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with dicyclohexylmethane diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen to react for 1.5 hours to obtain a prepolymer solution a, wherein the using amount of dibutyltin dilaurate is 0.02% of the mass of dicyclohexylmethane diisocyanate, and the mass molar ratio of N, N-dimethylacetamide to dicyclohexylmethane diisocyanate is 7.74g:3.5 mol, wherein the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the disulfide bond-containing macrodiol and the chain extender is 1.1: 1;

(1.3) adding 1, 6-hexanediol into the prepolymer solution a, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of caprolactone to dicyclohexylmethane diisocyanate to 1, 6-hexanediol is 2.5:3.5: 1.35;

(2.1) mixing polytetrahydrofuran with dicyclohexylmethane diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen for 1.5 hours to obtain a prepolymer solution b, wherein the molecular weight of the polytetrahydrofuran is 2000, the amount of dibutyltin dilaurate is 0.02% of the mass of the polytetrahydrofuran, and the mass molar ratio of the N, N-dimethylacetamide to the dicyclohexylmethane diisocyanate is 5.4g:3.5 mmol;

(2.2) adding 1, 6-hexanediol into the prepolymer solution b, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of polytetrahydrofuran, dicyclohexylmethane diisocyanate and 1, 6-hexanediol is 0.75:3.5:6.69, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in polytetrahydrofuran and 1, 6-hexanediol is 1.1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 1.25:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 5.5 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 5.1 MPa.

Example 4

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing caprolactone, dithiodiethanol and zinc acetate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain the macromolecular dihydric alcohol containing the disulfide bond, wherein the using amount of the dithiodiethanol is 0.3% of the mass of the caprolactone, the using amount of the zinc acetate is 0.02% of the mass of the caprolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing the disulfide bond is 2000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with isophorone diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen for reaction for 1.5 hours to obtain a prepolymer solution a, wherein the using amount of dibutyltin dilaurate is 0.02% of the mass of isophorone diisocyanate, and the mass molar ratio of N, N-dimethylacetamide to isophorone diisocyanate is 7.74g:3.5 mol, wherein the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the disulfide bond-containing macrodiol and the chain extender is 1.1: 1;

(1.3) adding 1, 6-hexanediol into the prepolymer solution a, maintaining the reaction conditions, and continuously reacting for 2.5 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of caprolactone to isophorone diisocyanate to 1, 6-hexanediol is 2.5:3.5: 1.35;

(2.1) mixing polytetrahydrofuran with isophorone diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen for 1.5 hours to react to obtain a prepolymer solution b, wherein the molecular weight of the polytetrahydrofuran is 2000, the using amount of dibutyltin dilaurate is 0.02% of the mass of the polytetrahydrofuran, and the mass molar ratio of the N, N-dimethylacetamide to the isophorone diisocyanate is 5.4g:3.5 mmol;

(2.2) adding 1, 6-hexanediol into the prepolymer solution b, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of polytetrahydrofuran, isophorone diisocyanate and 1, 6-hexanediol is 0.75:3.5:6.69, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in polytetrahydrofuran and 1, 6-hexanediol is 1.1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 1:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 6.5 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 5.8 MPa.

Example 5

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing caprolactone, dithiodiethanol and zinc acetate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain the macromolecular dihydric alcohol containing the disulfide bond, wherein the using amount of the dithiodiethanol is 0.3% of the mass of the caprolactone, the using amount of the zinc acetate is 0.02% of the mass of the caprolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing the disulfide bond is 2000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with hexamethylene diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen for reaction for 1.5 hours to obtain a prepolymer solution a, wherein the using amount of dibutyltin dilaurate is 0.02% of the mass of hexamethylene diisocyanate, and the mass molar ratio of N, N-dimethylacetamide to hexamethylene diisocyanate is 7.74g:3.5 mol, wherein the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the disulfide bond-containing macrodiol and the chain extender is 1.1: 1;

(1.3) adding 1, 6-hexanediol into the prepolymer solution a, maintaining the reaction conditions, and continuously reacting for 2.5 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of caprolactone to hexamethylene diisocyanate to 1, 6-hexanediol is 2.5:3.5: 1.35;

(2.1) mixing polytetrahydrofuran with hexamethylene diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen for 1.5 hours to obtain a prepolymer solution b, wherein the molecular weight of the polytetrahydrofuran is 2000, the using amount of dibutyltin dilaurate is 0.02% of the mass of the polytetrahydrofuran, and the mass molar ratio of the N, N-dimethylacetamide to the hexamethylene diisocyanate is 5.4g:3.5 mmol;

(2.2) adding 1, 6-hexanediol into the prepolymer solution b, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of polytetrahydrofuran to hexamethylene diisocyanate to 1, 6-hexanediol is 0.75:3.5:6.69, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in polytetrahydrofuran and 1, 6-hexanediol is 1.1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 1:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 2.4 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 2.0 MPa.

Example 6

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing caprolactone, dithiodiethanol and zinc acetate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain the macromolecular dihydric alcohol containing the disulfide bond, wherein the using amount of the dithiodiethanol is 0.3% of the mass of the caprolactone, the using amount of the zinc acetate is 0.02% of the mass of the caprolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing the disulfide bond is 2000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with toluene diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring at 75 ℃, 200r/min and under the protection of nitrogen for reaction for 1.5 hours to obtain a prepolymer solution a, wherein the using amount of dibutyltin dilaurate is 0.02% of the mass of the toluene diisocyanate, and the mass molar ratio of the N, N-dimethylacetamide to the toluene diisocyanate is 7.74g:3.5 mol, wherein the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the disulfide bond-containing macrodiol and the chain extender is 1.1: 1;

(1.3) adding 1, 6-hexanediol into the prepolymer solution a, maintaining the reaction conditions, and continuously reacting for 2.5 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of caprolactone to toluene diisocyanate to 1, 6-hexanediol is 2.5:3.5: 1.35;

(2.1) mixing polytetrahydrofuran with toluene diisocyanate, N, N-dimethylacetamide and dibutyltin dilaurate, and stirring for reaction for 1.5 hours at 75 ℃ under 200r/min in a nitrogen protection environment to obtain a prepolymer solution b, wherein the molecular weight of the polytetrahydrofuran is 2000, the using amount of dibutyltin dilaurate is 0.02% of the mass of the polytetrahydrofuran, and the mass molar ratio of the N, N-dimethylacetamide to the toluene diisocyanate is 5.4g:3.5 mmol;

(2.2) adding 1, 6-hexanediol into the prepolymer solution b, maintaining the reaction condition, and continuously reacting for 2.5 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of polytetrahydrofuran, toluene diisocyanate and 1, 6-hexanediol is 0.75:3.5:6.69, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in polytetrahydrofuran and 1, 6-hexanediol is 1.1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 1:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 8.1 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 7.5 MPa.

Example 7

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing valerolactone, dithiodiethanol and tin isooctanoate, and reacting at 120 ℃ in a nitrogen atmosphere for 6 hours to obtain macromolecular dihydric alcohol containing disulfide bonds, wherein the using amount of the dithiodiethanol is 0.2 percent of the mass of the valerolactone, the using amount of the zinc isooctanoate is 0.01 percent of the mass of the valerolactone, and the molecular weight of the prepared macromolecular dihydric alcohol containing disulfide bonds is 1000;

(1.2) mixing the prepared macromolecule dihydric alcohol containing the disulfide bond with isophorone diisocyanate, ethyl acetate and stannous octoate, and reacting for 2 hours at 60 ℃ under 250r/min and under the environment of nitrogen protection to obtain a prepolymer solution a, wherein the using amount of the stannous octoate is 0.2% of the mass of the isophorone diisocyanate, the mass molar ratio of the ethyl acetate to the isophorone diisocyanate is 7.8g:3mmol, and the molar ratio of the isocyanate group to the total number of hydroxyl groups contained in the macromolecule dihydric alcohol containing the disulfide bond and 1, 2-ethylene glycol is 1: 1;

(1.3) adding 1, 2-ethylene glycol into the prepolymer solution a, maintaining the reaction conditions, and continuously reacting for 2 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of valerolactone, isophorone diisocyanate and 1, 2-ethylene glycol is 2.5:3.5: 1.35;

(2.1) mixing polyethylene glycol with isophorone diisocyanate, ethyl acetate and stannous octoate, and reacting for 2 hours at 60 ℃, 20 and 50r/min under the nitrogen protection environment to obtain a prepolymer solution b, wherein the molecular weight of the polyethylene glycol is 1000, the using amount of the stannous octoate is 0.01 percent of the mass of the polyethylene glycol, and the mass molar ratio of the ethyl acetate to the isophorone diisocyanate is 5.3g:3.5 mmol;

(2.2) adding 1, 2-ethylene glycol into the prepolymer solution b, maintaining the reaction conditions, and continuously reacting for 3 hours to obtain a hard polyurethane solution, wherein the molar ratio of polyethylene glycol, isophorone diisocyanate and 1, 2-ethylene glycol is 0.7:3:6.64, and the molar ratio of isocyanate groups to the total number of hydroxyl groups in the polyethylene glycol and the 1, 2-ethylene glycol is 1: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 0.25:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 4.7 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 4.2 MPa.

Example 8

A self-repairing polyurethane material is prepared by the following steps:

(1.1) mixing tetrahydrofuran, dithiodipropanol and stannic chloride, and reacting for 6 hours at 120 ℃ in a nitrogen atmosphere to obtain macromolecular dihydric alcohol containing disulfide bonds, wherein the using amount of the dithiodipropanol is 0.4% of the mass of the tetrahydrofuran, the using amount of the stannic chloride is 0.2% of the mass of the tetrahydrofuran, and the molecular weight of the prepared macromolecular dihydric alcohol containing disulfide bonds is 5000;

(1.2) mixing the prepared macromolecular diol containing the disulfide bond with naphthalene diisocyanate, butanone and triethylamine, and reacting for 1 hour at 90 ℃ under 150r/min and under the environment of nitrogen protection to obtain a prepolymer solution a, wherein the amount of the triethylamine is 0.01 percent of the mass of the naphthalene diisocyanate, the mass molar ratio of the butanone to the naphthalene diisocyanate is 7.6g:3.5mmol, and the molar ratio of isocyanate groups to the total number of hydroxyl groups contained in the macromolecular diol containing the disulfide bond and 1, 3-propanediol is 2.2: 1;

(1.3) adding 1, 3-propylene glycol into the prepolymer solution a, maintaining the reaction conditions, and continuously reacting for 2 hours to obtain a polyurethane solution containing a disulfide bond, wherein the molar ratio of tetrahydrofuran to naphthalene diisocyanate to 1, 3-propylene glycol is 2.2:3.3: 1.33;

(2.1) mixing polypropylene glycol with naphthalene diisocyanate, butanone and triethylamine, and reacting for 2 hours at 90 ℃ under the environment of 150r/min and nitrogen protection to obtain a prepolymer solution b, wherein the molecular weight of the polypropylene glycol is 3000, the amount of the triethylamine is 0.2 percent of the mass of the polypropylene glycol, and the mass molar ratio of the butanone to the naphthalene diisocyanate is 5.5g:3 mmol;

(2.2) adding 1, 3-propylene glycol into the prepolymer solution b, maintaining the reaction conditions, and continuously reacting for 2 hours to obtain a hard-segment polyurethane solution, wherein the molar ratio of the polypropylene glycol to the naphthalene diisocyanate to the 1, 3-propylene glycol is 0.8:3.5:6.69, and the molar ratio of the isocyanate group to the total number of hydroxyl groups in the polypropylene glycol and the 1, 3-propylene glycol is 2.2: 1;

(3) and mixing the disulfide bond-containing polyurethane solution and the hard segment polyurethane solution, and then sequentially carrying out primary drying and secondary drying to prepare the solid self-repairing polyurethane material, wherein the mass ratio of the disulfide bond-containing polyurethane solution to the hard segment polyurethane solution is 2:1, the primary drying treatment temperature is 80 ℃, the treatment time is 18 hours, the secondary drying treatment temperature is 120 ℃, and the treatment time is 5 hours.

And (5) observing the mechanical property and the self-repairing property of the material by using a dynamic mechanical analyzer. The strength of the polyurethane material is 3.5 Mpa; the materials are spliced together after being completely cut off, and are placed at 60 ℃ for 24 hours under the state of applying external force, and the strength is 2.9 MPa.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.