Epoxy modified polyurethane self-repairing elastomer as well as preparation method and application thereof

Abstract

The invention discloses an epoxy modified polyurethane self-repairing elastomer as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out a reaction on polydimethylsiloxane and diisocyanate to prepare a polydimethylsiloxane-polyurethane sol; mixing the polydimethylsiloxane-polyurethane sol with an epoxy end chain extender and a photoinitiator to react, so as to prepare epoxy modified polyurethane sol; and carrying out ultraviolet light curing treatment on the epoxy modified polyurethane sol, so as to prepare the epoxy modified polyurethane self-repairing elastomer. According to the prepared epoxy modified polyurethane self-repairing elastomer, an annular structure and a benzene ring structure are introduced through the chain extender, the mechanical property of the elastomer can be effectively improved, and due to the addition of the epoxy end chain extender, the annular structure and the benzene ring structure can be introduced into a linear polymer chain to improve the mechanical property of the elastomer; and an epoxy group and a photoinitiator are introduced into an original hydrogen bond self-repairing network, so that ultraviolet light driven self-repairing is realized to improve the self-repairing performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible sensor materials, and particularly relates to an epoxy-modified polyurethane self-healing elastomer and its preparation method and application. Background Art

[0002] Compared with traditional materials, self-healing polymer materials have the advantages of good chemical stability, outstanding corrosion resistance, light weight, good flexibility, easy molding, low cost, etc. Therefore, they play a crucial role in many application fields. At present, self-healing polymer materials have been widely used in fields such as biomaterials, anti-corrosion coatings, and flexible electronic devices. With the advent of the digital information age, the research and development of high-performance portable flexible sensor devices have developed rapidly, and they are expected to be applied in fields such as human motion and health monitoring, intelligent robots, and wearable electronic devices.

[0003] Polysiloxane has been widely used in fields such as flexible electronic devices, biomedicine, and electronic skin due to its low cost, biocompatibility, and easy combination with electronic materials. For polysiloxane-based polyurethane self-healing elastomers, a patent with the publication number CN117866168A discloses a bio-based self-healing high-strength and high-toughness polyurethane material and its preparation method. This material uses hydroxyl-terminated polydimethylsiloxane and isophorone diisocyanate as the main chain, and inorganic salts are introduced into the cross-linked network to improve the rigidity of the material. Its tensile strength can be as high as 66 MPa, but the self-healing efficiency of the tensile strength of this material is only 79.5% under the hot pressing condition of 100 °C in a flat vulcanizer. Its high-temperature hot pressing self-healing conditions and low self-healing efficiency limit the application of the material in human sensors; a patent with the publication number CN118255964A discloses a preparation method of a room-temperature self-healing polyurethane elastomer. This material uses dihydroxy-terminated polydimethylsiloxane and isophorone diisocyanate as raw materials, and 4,4'-diaminodiphenyl disulfide and 2,6-pyridinedimethanol as chain extenders, and is synthesized by one-pot condensation polymerization into a polyurethane elastomer with excellent self-healing performance, but the highest tensile strength of this material is less than 0.1 MPa. Its poor mechanical properties are likely to cause the elastomer to lose support during the application of the flexible sensor, thereby affecting the service life of the flexible sensor; therefore, it is an urgent problem to provide a self-healing polyurethane elastomer with excellent flexibility. Summary of the Invention

[0004] The main purpose of the present invention is to provide an epoxy-modified polyurethane self-healing elastomer and its preparation method and application to overcome the deficiencies of the prior art.

[0005] To achieve the foregoing invention purpose, the technical solutions adopted by the present invention include: An embodiment of the present invention provides a method for preparing an epoxy-modified polyurethane self-healing elastomer, which includes: Reacting polydimethylsiloxane with diisocyanate to obtain a polydimethylsiloxane-polyurethane sol; Mixing and reacting the polydimethylsiloxane-polyurethane sol with an epoxy-terminated chain extender and a photoinitiator to obtain an epoxy-modified polyurethane sol; And, subjecting the epoxy-modified polyurethane sol to ultraviolet light curing treatment to obtain an epoxy-modified polyurethane self-healing elastomer.

[0006] An embodiment of the present invention also provides an epoxy-modified polyurethane self-healing elastomer prepared by the foregoing preparation method.

[0007] An embodiment of the present invention also provides the use of the foregoing epoxy-modified polyurethane self-healing elastomer in a flexible sensor.

[0008] An embodiment of the present invention also provides a self-healing method for an epoxy-modified polyurethane self-healing elastomer, which includes: subjecting the foregoing epoxy-modified polyurethane self-healing elastomer with damaged surface to ultraviolet irradiation treatment, thereby realizing the self-healing of the epoxy-modified polyurethane self-healing elastomer.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The epoxy-modified polyurethane self-healing elastomer prepared by the present invention introduces a cyclic structure and a benzene ring structure through a chain extender, which can effectively improve the mechanical properties of the elastomer. For example, the tensile strength can reach 4 ± 2.1 MPa, and the elongation at break can reach 453 ± 28.3%. At the same time, the elastomer prepared by the present invention has excellent flexibility, and its mechanical properties are more suitable for the field of human motion health monitoring in the application of flexible sensors; (2) The epoxy structure and photoinitiator introduced in the epoxy-modified polyurethane self-healing elastomer prepared by the present invention can undergo ring-opening polymerization reaction under ultraviolet light irradiation conditions, adding ultraviolet light-driven self-healing on the basis of traditional heat-driven self-healing, thereby promoting the self-healing efficiency of the elastomer; the self-healing efficiency of the fracture strength of the epoxy-modified polyurethane self-healing elastomer prepared by the present invention can reach up to 95% at 70 °C, and the self-healing efficiency of the elongation at break can reach up to 107%; under the irradiation of an 80 W 365 nm ultraviolet lamp, the scratches on the sample surface can completely disappear within 50 min, and its milder self-healing conditions and better self-healing efficiency are more suitable for the field of wearable electronic skin.

[0010] (3) In the epoxy-modified polyurethane self-healing elastomer prepared by the present invention, the ring-opening of epoxy groups is promoted by a photoinitiator and ultraviolet light irradiation, and photo-crosslinking is achieved with the polymer chain, which can assist the introduction of an epoxy chain extender, ensuring the simplicity of the preparation process while increasing the crosslinking degree. Description of the Drawings

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0012] Figures 1a - 1c It is the tensile stress-strain curve image of the elastomer in Embodiments 1-3 of the present invention; Figures 2a - 2c It is the tensile stress-strain curve image of the elastomer in Embodiments 4-6 and Comparative Examples 1-3 of the present invention; Figures 3a - 3c It is the tensile stress-strain curve image of the elastomer in Embodiments 7-9 of the present invention.

[0013] Figures 4a - 4c It is the image of the tensile stress-strain curve of the elastomer after self-healing at 70°C for 24 hours and the tensile stress-strain curve of the elastomer before self-healing in Embodiments 1, 5, and 7 of the present invention; Figure 5 It is the optical micrograph of the elastomer in Embodiment 1 of the present invention before and after self-healing at room temperature; Figure 6 It is the optical micrograph of the elastomer in Embodiment 1 of the present invention before and after self-healing under the heating condition of 60°C; Figure 7 It is the optical micrograph of the elastomer in Embodiment 1 of the present invention before and after self-healing under the irradiation condition of a 365 nm ultraviolet lamp with 80 W; Figure 8 It is the optical micrograph of the elastomer in Comparative Example 4 of the present invention before and after self-healing under the irradiation condition of a 365 nm ultraviolet lamp with 80 W. Detailed Embodiments

[0014] In view of the deficiencies of the prior art, through long-term research and a large number of practices, the inventor of this case was able to propose the technical solution of the present invention, which mainly uses polydimethylsiloxane, diisocyanate, epoxy end-chain extender and photoinitiator as raw materials to prepare an epoxy-modified polyurethane self-healing elastomer. Polydimethylsiloxane can form a prepolymer polydimethylsiloxane-polyurethane (PDMS-PU) with a self-healing network with hydrogen bond interaction between the isocyanate groups in diisocyanate. Then, the prepolymer is mixed with a photoinitiator and an epoxy end-chain extender to prepare an epoxy-modified polyurethane (PDMS-PUE) sol, and the epoxy-modified polyurethane (PDMS-PUE) elastomer is obtained by ultraviolet curing. The addition of the epoxy end-chain extender can not only introduce a cyclic structure and a benzene ring structure into the linear polymer chain to improve the mechanical properties of the elastomer, but also introduce epoxy groups and a photoinitiator into the original hydrogen bond self-healing network to achieve ultraviolet light-driven self-healing and improve the self-healing performance.

[0015] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0016] Specifically, as an aspect of the technical solution of the present invention, a preparation method of an epoxy-modified polyurethane self-healing elastomer involves: React polydimethylsiloxane with diisocyanate to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol; Mix and react the polydimethylsiloxane-polyurethane sol with an epoxy end-chain extender and a photoinitiator to obtain an epoxy-modified polyurethane (PDMS-PUE) sol; And, perform ultraviolet light curing treatment on the epoxy-modified polyurethane sol to obtain an epoxy-modified polyurethane (PDMS-PUE) self-healing elastomer.

[0017] In some preferred implementation schemes, the preparation method specifically includes: Dissolve polydimethylsiloxane and diisocyanate in a first organic solvent respectively to form a polydimethylsiloxane solution and a diisocyanate solution; And, in a protective atmosphere, mix the polydimethylsiloxane solution and the diisocyanate solution at 40-100 °C and stir and react for 1-48 h to obtain polydimethylsiloxane-polyurethane sol.

[0018] Further, the polydimethylsiloxane includes any one or a combination of more than one of monoamino-terminated polydimethylsiloxane, diamino-terminated polydimethylsiloxane, monohydroxy-terminated polydimethylsiloxane, dihydroxy-terminated polydimethylsiloxane, hydroxy-terminated polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, and dihydroxyalkyl-terminated polydimethylsiloxane, and is not limited thereto.

[0019] Further, the diisocyanate includes any one or a combination of more than one of isophorone diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, cyclohexyl isocyanate, diphenylmethane diisocyanate, phthalic diisocyanate, toluene diisocyanate, and octadecyl diisocyanate, and is not limited thereto.

[0020] Further, the first organic solvent includes any one or a combination of more than one of tetrahydrofuran, chloroform, dimethylacetamide, dichloromethane, and ethanol, and is not limited thereto.

[0021] Further, the protective atmosphere includes any one or a combination of more than one of nitrogen atmosphere, argon atmosphere, and helium atmosphere, and is not limited thereto.

[0022] Further, the molar ratio of the polydimethylsiloxane to the diisocyanate is 1:1 - 4.

[0023] In some preferred embodiments, the preparation method specifically includes: Mixing the epoxy chain extender with a second organic solvent to form an epoxy chain extender solution; And reacting the epoxy chain extender solution with the polydimethylsiloxane-polyurethane sol at 40 - 100 °C for 1 - 48 h to obtain an epoxy-modified polyurethane sol.

[0024] Further, the epoxy chain extender includes [3-(glycidyl ether group)propyl]-terminated siloxane and / or glycidyl ether; wherein, the [3-(glycidyl ether group)propyl]-terminated siloxane includes any one or a combination of more than one of [3-(glycidyl ether group)propyl]-terminated polydimethylsiloxane, [3-(glycidyl ether group)propyl]-terminated cyclic siloxane, [3-(glycidyl ether group)propyl]-terminated ladder-type sesquisiloxane, [3-(glycidyl ether group)propyl]-terminated cage-type sesquisiloxane, [3-(glycidyl ether group)propyl]trimethoxysilane, and [3-(glycidyl ether group)propyl]triethoxysilane; the glycidyl ether includes any one or a combination of more than one of glycidyl phenyl ether, bisphenol A glycidyl ether, bisphenol F glycidyl ether, octyl glycidyl ether, xylene glycidyl ether, and poly(propylene glycol) diglycidyl ether, and is not limited thereto.

[0025] Further, the second organic solvent includes any one or a combination of more than one of tetrahydrofuran, dimethylacetamide, and chloroform, and is not limited thereto.

[0026] Further, the mass ratio of the epoxy chain extender to the sum of polydimethylsiloxane and diisocyanate is 1-20:100.

[0027] Further, the molar ratio of the epoxy chain extender to the sum of polydimethylsiloxane and diisocyanate is 1-5:10.

[0028] In some preferred embodiments, the preparation method specifically includes: subjecting the epoxy-modified polyurethane sol to ultraviolet irradiation treatment at room temperature for 1-10 h to obtain an epoxy-modified polyurethane self-healing elastomer.

[0029] Further, the ultraviolet wavelength used in the ultraviolet irradiation treatment is 300-400 nm.

[0030] Further, the power of the ultraviolet lamp used in the ultraviolet irradiation treatment is 40-200 W.

[0031] Another aspect of the embodiments of the present invention also provides an epoxy-modified polyurethane self-healing elastomer prepared by the foregoing preparation method.

[0032] Another aspect of the embodiments of the present invention also provides the use of the foregoing epoxy-modified polyurethane self-healing elastomer in a flexible sensor.

[0033] Another aspect of the embodiments of the present invention also provides a self-healing method for an epoxy-modified polyurethane self-healing elastomer, which includes: subjecting the surface-damaged foregoing epoxy-modified polyurethane self-healing elastomer to ultraviolet irradiation treatment, thereby realizing the self-healing of the epoxy-modified polyurethane self-healing elastomer.

[0034] The present invention uses polydimethylsiloxane as a soft segment to react with diisocyanate to obtain a polysiloxane-polyurea structure in which double hydrogen bonds are formed between the ureido groups in the structure. However, only linear structures are contained in this system, and large deformations are likely to occur under external forces. The introduction of epoxy chain extenders (epoxy-terminated siloxanes, glycidyl ethers) can effectively modify the polymer. The cyclic structure and benzene ring structure in the chain extender can improve the mechanical strength of the material, and its planar structure has better compatibility with the linear structure of polydimethylsiloxane-polyurethane (PDMS-PU). The epoxy structure and photoinitiator in the chain extender can undergo ring-opening polymerization reactions under ultraviolet light irradiation conditions, which can not only tightly bind the chain extender to the polydimethylsiloxane-polyurethane (PDMS-PU) segments, but also promote the self-healing efficiency of the elastomer through photocrosslinking. The epoxy-modified polyurethane self-healing elastomer prepared by the present invention has excellent mechanical properties and has excellent application prospects in the aspect of flexible sensor substrates for realizing human motion detection.

[0035] The technical solution of the present invention will be further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0036] The experimental materials used in the following examples can be purchased from conventional biochemical reagent companies without special instructions.

[0037] Example 1 (1) Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask. After stirring at room temperature for 10 min, raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask. After stirring at 60 °C for 18 h, a polydimethylsiloxane-polyurethane (PDMS-PU) sol is obtained.

[0038] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-1) composite sol: Weigh 1 wt% of glycidyl ether oxypropyl cyclotetrasiloxane based on the total mass of amino-terminated polydimethylsiloxane (PDMS) and isophorone diisocyanate (IPDI) into a 20 mL sample bottle, add an appropriate amount of tetrahydrofuran for dilution, and then slowly inject the diluted glycidyl ether oxypropyl cyclotetrasiloxane and photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol using a disposable syringe. Continue the reaction at 60 °C for 6 h to obtain the epoxy-modified polyurethane (PDMS-PUE-1) composite sol.

[0039] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-1) composite sol into a mold, cure it under 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain the epoxy-modified polyurethane (PDMS-PUE-1) elastomer.

[0040] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-1) elastomer prepared in this example is as Figure 1a shown. The fracture strength can reach 2.89 MPa, and the elongation at break can reach 362%. The self-healing efficiency of the epoxy-modified polyurethane (PDMS-PUE-1) elastomer prepared in this example after self-healing at 70 °C for 24 h is as Figure 4a shown. The self-healing efficiency of the fracture strength can reach 93%, and the self-healing efficiency of the elongation at break can reach 92%. Figure 5 、 Figure 6 and Figure 7 are the optical micrographs before and after surface scratch self-healing of the epoxy-modified polyurethane (PDMS-PUE-1) elastomer prepared in this example under room temperature natural conditions, 60 °C heating conditions, and 80 W of 365 nm ultraviolet lamp irradiation conditions, respectively. Under room temperature conditions, some scratches can still be seen within 60 min on the surface; under 60 °C heating conditions, the surface scratches can basically disappear within 60 min; under 80 W of 365 nm ultraviolet lamp irradiation conditions, the surface scratches can completely disappear within 50 min. Compared with the polydimethylsiloxane-polyurethane [PDMS-PU] prepared in Comparative Example 4, the scratch repair effect of the epoxy-modified polyurethane (PDMS-PUE-1) elastomer after 50 min of irradiation with an 80 W 365 nm ultraviolet lamp is better than that of the unmodified epoxy polydimethylsiloxane-polyurethane [PDMS-PU] elastomer. When using ultraviolet lamp irradiation, due to the presence of many unopened epoxy groups in the system, the epoxy groups in glycidyl ether oxypropyl cyclotetrasiloxane undergo ring-opening reactions under the irradiation of the ultraviolet lamp, generating more hydrogen bond sites that can promote the re-formation of hydrogen bond interactions at the scratch, thereby improving the self-healing efficiency.

[0041] Example 2 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0042] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-2) composite sol: Weigh 10 wt% of glycidyl ether oxypropyl cyclotetrasiloxane based on the total mass of amino-terminated polydimethylsiloxane (PDMS) and isophorone diisocyanate (IPDI) into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the glycidyl ether oxypropyl cyclotetrasiloxane diluted with tetrahydrofuran and the photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane (PDMS-PUE-2) composite sol.

[0043] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-2) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane (PDMS-PUE-2) elastomer.

[0044] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-2) elastomer prepared in this example is as Figure 1b shown.

[0045] Example 3 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min, and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0046] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-3) composite sol: Weigh 20 wt% of glycidyl ether oxypropyl cyclotetrasiloxane based on the total mass of amino-terminated polydimethylsiloxane (PDMS) and isophorone diisocyanate (IPDI) into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the glycidyl ether oxypropyl cyclotetrasiloxane diluted with tetrahydrofuran and a photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane (PDMS-PUE-3) composite sol.

[0047] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-3) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane (PDMS-PUE-3) elastomer.

[0048] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-3) elastomer prepared in this example is as Figure 1c shown.

[0049] Example 4 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min, and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0050] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-4) composite sol: Weigh 0.1 mmol of bisphenol A diglycidyl ether into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the bisphenol A diglycidyl ether diluted with tetrahydrofuran and the photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane (PDMS-PUE-4) composite sol.

[0051] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-4) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane (PDMS-PUE-4) elastomer.

[0052] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-4) elastomer prepared in this example is as Figure 2a shown. Compared with the epoxy-modified polyurethane [PDMS-PUE-4 (without photoinitiator)] prepared in Comparative Example 1, the tensile strength of the epoxy-modified polyurethane (PDMS-PUE-4) is 3.90 MPa, which is greater than 3.5 MPa of the epoxy-modified polyurethane [PDMS-PUE-4 (without photoinitiator)], and the elongation at break of the epoxy-modified polyurethane (PDMS-PUE-4) is 453.28%, which is greater than 382.61% of the epoxy-modified polyurethane [PDMS-PUE-4 (without photoinitiator)]. It is proved that the introduction of the photoinitiator is beneficial to the crosslinking degree of bisphenol A diglycidyl ether and polydimethylsiloxane-polyurethane (PDMS-PU).

[0053] Example 5 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask. After stirring at room temperature for 10 min, raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask. After stirring at 60 °C for 18 h, obtain the polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0054] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-5) composite sol: Weigh 0.2 mmol of bisphenol A diglycidyl ether into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the bisphenol A diglycidyl ether diluted with tetrahydrofuran and the photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain the epoxy-modified polyurethane (PDMS-PUE-5) composite sol.

[0055] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-5) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain the epoxy-modified polyurethane (PDMS-PUE-5) elastomer.

[0056] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-5) elastomer prepared in this example is as Figure 2b shown. Compared with the epoxy-modified polyurethane [PDMS-PUE-5 (without photoinitiator)] prepared in Comparative Example 2, the tensile strength of the epoxy-modified polyurethane (PDMS-PUE-5) is 4.21 MPa, which is greater than 3.62 MPa of the epoxy-modified polyurethane [PDMS-PUE-5 (without photoinitiator)], and the elongation at break of the epoxy-modified polyurethane (PDMS-PUE-5) is 481.34%, which is greater than 413.12% of the epoxy-modified polyurethane [PDMS-PUE-5 (without photoinitiator)]. It is proved that the introduction of the photoinitiator is beneficial to the crosslinking degree of bisphenol A diglycidyl ether and polydimethylsiloxane-polyurethane (PDMS-PU).

[0057] The self-healing efficiency of the epoxy-modified polyurethane (PDMS-PUE-5) elastomer prepared in this example after self-healing at 70 °C for 24 h is as Figure 4bAs shown, the self-healing efficiency of the elongation at break can reach 99%.

[0058] Example 6 (1) Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0059] (2) Preparation of epoxy-modified polyurethane (PDMS-PUE-6) composite sol: Weigh 0.4 mmol of bisphenol A diglycidyl ether into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the bisphenol A diglycidyl ether diluted with tetrahydrofuran and the photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h.

[0060] (3) Pour the epoxy-modified polyurethane (PDMS-PUE-6) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane (PDMS-PUE-6) elastomer.

[0061] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-6) elastomer prepared in this example is as Figure 2c shown. Compared with the epoxy-modified polyurethane [PDMS-PUE-6 (without photoinitiator)] prepared in Comparative Example 3, the tensile strength of the epoxy-modified polyurethane (PDMS-PUE-6) is 3.61 MPa, which is greater than 2.63 MPa of the epoxy-modified polyurethane [PDMS-PUE-6 (without photoinitiator)], and the elongation at break of the epoxy-modified polyurethane (PDMS-PUE-6) is 403.60%, which is greater than 369.34% of the epoxy-modified polyurethane [PDMS-PUE-6 (without photoinitiator)]. It is proved that the introduction of the photoinitiator is beneficial to the crosslinking degree of bisphenol A diglycidyl ether and polydimethylsiloxane-polyurethane (PDMS-PU).

[0062] Example 7 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask. After stirring at room temperature for 10 min, raise the temperature to 60 °C. Then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0063] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-7) composite sol: Weigh 0.1 mmol of epoxy-terminated polydimethylsiloxane into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the epoxy-terminated polydimethylsiloxane diluted with tetrahydrofuran and a photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane (PDMS-PUE-7) composite sol.

[0064] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-7) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane (PDMS-PUE-7) elastomer.

[0065] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-7) elastomer prepared in this example is as Figure 3a shown. The self-healing efficiency of the epoxy-modified polyurethane (PDMS-PUE-7) elastomer prepared in this example after self-healing at 70 °C for 24 h is as Figure 4c shown. The self-healing efficiency of the breaking strength can reach 95%, and the self-healing efficiency of the elongation at break can reach 107%, which is better than the elongation at break before self-healing.

[0066] Example 8 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask. Stir at room temperature for 10 min and then raise the temperature to 60 °C. Then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask. Stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0067] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-8) composite sol: Weigh 0.2 mmol of epoxy-terminated polydimethylsiloxane into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Then use a disposable syringe to slowly inject the epoxy-terminated polydimethylsiloxane diluted with tetrahydrofuran and a photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain the epoxy-modified polyurethane (PDMS-PUE-8) composite sol.

[0068] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-8) composite sol into a mold and cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain the epoxy-modified polyurethane (PDMS-PUE-8) elastomer.

[0069] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-8) elastomer prepared in this example is as Figure 3b shown.

[0070] Example 9 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min, and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0071] (2)Preparation of epoxy-modified polyurethane (PDMS-PUE-9) composite sol: Weigh 0.4 mmol of epoxy-terminated polydimethylsiloxane into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the epoxy-terminated polydimethylsiloxane diluted with tetrahydrofuran and a photoinitiator into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane (PDMS-PUE-9) composite sol.

[0072] (3)Pour the epoxy-modified polyurethane (PDMS-PUE-9) composite sol into a mold, cure it with 80 W of 365 nm ultraviolet light for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane (PDMS-PUE-9) elastomer.

[0073] The tensile stress-strain curve image of the epoxy-modified polyurethane (PDMS-PUE-9) elastomer prepared in this example is as Figure 3c shown.

[0074] Comparative Example 1 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask. Stir at room temperature for 10 min and then raise the temperature to 60 °C. Then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask. Stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0075] (2)Preparation of epoxy-modified polyurethane [PDMS-PUE-4 (non-glossy)] composite sol: Weigh 0.1 mmol of bisphenol A diglycidyl ether into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the bisphenol A diglycidyl ether diluted with tetrahydrofuran into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane [PDMS-PUE-4 (non-glossy)] composite sol.

[0076] (3)Pour the epoxy-modified polyurethane [PDMS-PUE-4 (non-glossy)] composite sol into a mold, cure it at room temperature for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane [PDMS-PUE-4 (non-glossy)] elastomer.

[0077] The tensile stress-strain curve image of the epoxy-modified polyurethane [PDMS-PUE-4 (non-glossy)] elastomer prepared in this comparative example is as Figure 2a shown.

[0078] Comparative Example 2 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min, and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0079] (2)Preparation of epoxy-modified polyurethane [PDMS-PUE-5 (matte)] composite sol: Weigh 0.2 mmol of bisphenol A diglycidyl ether into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the bisphenol A diglycidyl ether diluted with tetrahydrofuran into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h to obtain epoxy-modified polyurethane [PDMS-PUE-5 (matte)] composite sol.

[0080] (3)Pour the epoxy-modified polyurethane [PDMS-PUE-5 (matte)] composite sol into a mold, cure it at room temperature for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane [PDMS-PUE-5 (matte)] elastomer.

[0081] The tensile stress-strain curve image of the epoxy-modified polyurethane [PDMS-PUE-5 (matte)] elastomer prepared in this comparative example is as Figure 2b shown.

[0082] Comparative Example 3 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min, and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 18 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0083] (2)Preparation of epoxy-modified polyurethane [PDMS-PUE-6 (non-gloss)] composite sol: Weigh 0.4 mmol of bisphenol A diglycidyl ether into a 20 mL sample bottle, dilute it with an appropriate amount of tetrahydrofuran, and then use a disposable syringe to slowly inject the bisphenol A diglycidyl ether diluted with tetrahydrofuran into the polydimethylsiloxane-polyurethane (PDMS-PU) sol and continue to react at 60 °C for 6 h.

[0084] (3)Pour the epoxy-modified polyurethane [PDMS-PUE-6 (non-gloss)] composite sol into a mold, cure it at room temperature for 2 h, and then dry it at 60 °C for 6 h to obtain an epoxy-modified polyurethane [PDMS-PUE-6 (non-gloss)] elastomer.

[0085] The tensile stress-strain curve image of the epoxy-modified polyurethane [PDMS-PUE-6 (non-gloss)] elastomer prepared in this comparative example is as Figure 2c shown.

[0086] Comparative Example 4 (1)Preparation of polydimethylsiloxane-polyurethane (PDMS-PU) composite sol: Weigh 1 mmol of amino-terminated polydimethylsiloxane (PDMS) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran; then weigh 3 mmol of isophorone diisocyanate (IPDI) into a 20 mL sample bottle and dilute it with an appropriate amount of tetrahydrofuran. Under nitrogen protection, use a disposable syringe to inject the amino-terminated polydimethylsiloxane (PDMS) diluted with tetrahydrofuran into a 100 mL two-necked flask, stir at room temperature for 10 min, and then raise the temperature to 60 °C; then use a disposable syringe to slowly inject the isophorone diisocyanate (IPDI) diluted with tetrahydrofuran into the flask, and stir at 60 °C for 24 h to obtain polydimethylsiloxane-polyurethane (PDMS-PU) sol.

[0087] (2) Pour the polydimethylsiloxane-polyurethane [PDMS-PU] composite sol into a mold, cure it at room temperature for 2 h, and then dry it at 60 °C for 6 h to obtain a polydimethylsiloxane-polyurethane [PDMS-PU] elastomer.

[0088] The optical micrographs before and after surface scratch self-repair of the polydimethylsiloxane-polyurethane [PDMS-PU] elastomer prepared in this comparative example under the irradiation of an 80 W 365 nm ultraviolet lamp are as Figure 8 shown.

[0089] In addition, the inventors of this case also referred to the foregoing embodiments and conducted tests with other raw materials, process operations, and process conditions described in this specification, and all obtained relatively ideal results.

[0090] It should be understood that the technical solution of the present invention is not limited to the limitations of the above specific implementation cases. Any technical deformation made according to the technical solution of the present invention without departing from the spirit of the present invention and the scope protected by the claims falls within the protection scope of the present invention.

Claims

1. A preparation method of an epoxy-modified polyurethane self-healing elastomer, characterized in that, Comprising: Reacting polydimethylsiloxane with diisocyanate to obtain a polydimethylsiloxane-polyurethane sol; Mixing and reacting the polydimethylsiloxane-polyurethane sol with an epoxy-terminated chain extender and a photoinitiator to obtain an epoxy-modified polyurethane sol; And subjecting the epoxy-modified polyurethane sol to ultraviolet curing treatment to obtain an epoxy-modified polyurethane self-healing elastomer.

2. The preparation method according to claim 1, wherein, Specifically including: Dissolving polydimethylsiloxane and diisocyanate in a first organic solvent respectively to form a polydimethylsiloxane solution and a diisocyanate solution; And, in a protective atmosphere, mixing the polydimethylsiloxane solution and the diisocyanate solution at 40 - 100 °C and stirring and reacting for 1 - 48 h to obtain a polydimethylsiloxane-polyurethane sol.

3. The preparation method according to claim 2, characterized in that: The polydimethylsiloxane includes any one or a combination of more than one of monoamino-terminated polydimethylsiloxane, diamino-terminated polydimethylsiloxane, monohydroxy-terminated polydimethylsiloxane, dihydroxy-terminated polydimethylsiloxane, hydroxy-end-capped polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, and dihydroxyalkyl-terminated polydimethylsiloxane; And / or, the diisocyanate includes any one or a combination of more than one of isophorone diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, cyclohexyl isocyanate, diphenylmethane diisocyanate, phthalic diisocyanate, toluene diisocyanate, and octadecyl diisocyanate; And / or, the first organic solvent includes any one or a combination of more than one of tetrahydrofuran, chloroform, dimethylacetamide, dichloromethane, and ethanol; And / or, the protective atmosphere includes any one or a combination of more than one of nitrogen atmosphere, argon atmosphere, and helium atmosphere; And / or, the molar ratio of the polydimethylsiloxane to the diisocyanate is 1:1 - 4.

4. The preparation method according to claim 1, wherein Specifically including: Mixing the epoxy-terminated chain extender with a second organic solvent to form an epoxy-terminated chain extender solution; And mixing the epoxy-terminated chain extender solution with the polydimethylsiloxane-polyurethane sol and reacting at 40 - 100 °C for 1 - 48 h to obtain an epoxy-modified polyurethane sol.

5. The preparation method according to claim 4, characterized in that: The epoxy-terminated chain extender includes [3-(glycidyl ether group)propyl]-terminated siloxane and / or glycidyl ether; wherein, the [3-(glycidyl ether group)propyl]-terminated siloxane includes any one or a combination of more than one of [3-(glycidyl ether group)propyl]-terminated polydimethylsiloxane, [3-(glycidyl ether group)propyl]-terminated cyclic siloxane, [3-(glycidyl ether group)propyl]-terminated ladder-type sesquisiloxane, [3-(glycidyl ether group)propyl]-terminated cage-type sesquisiloxane, [3-(glycidyl ether group)propyl]trimethoxysilane, and [3-(glycidyl ether group)propyl]triethoxysilane; the glycidyl ether includes any one or a combination of more than one of glycidyl phenyl ether, bisphenol A glycidyl ether, bisphenol F glycidyl ether, octyl glycidyl ether, xylene glycidyl ether, and poly(propylene glycol) diglycidyl ether; And / or, the second organic solvent includes any one or a combination of more than one of tetrahydrofuran, dimethylacetamide, and chloroform; And / or, the mass ratio of the epoxy end-chain extender to the sum of polydimethylsiloxane and diisocyanate is 1-20:100; And / or, the molar ratio of the epoxy end-chain extender to the sum of polydimethylsiloxane and diisocyanate is 1-5:

10.

6. The preparation method according to claim 1, wherein Specifically, it includes: The epoxy-modified polyurethane sol is subjected to ultraviolet irradiation treatment at room temperature for 1-10 h to obtain an epoxy-modified polyurethane self-healing elastomer.

7. The preparation method according to claim 6, characterized in that: The ultraviolet wavelength used in the ultraviolet irradiation treatment is 300-400 nm; And / or, the power of the ultraviolet lamp used in the ultraviolet irradiation treatment is 40-200 W.

8. An epoxy-modified polyurethane self-healing elastomer prepared by the preparation method according to any one of claims 1-7.

9. Use of the epoxy-modified polyurethane self-healing elastomer according to claim 8 in a flexible sensor.

10. A self - healing method for an epoxy - modified polyurethane self - healing elastomer, characterized in that, It includes: The epoxy-modified polyurethane self-healing elastomer with damaged surface is subjected to ultraviolet irradiation treatment, so as to realize the self-healing of the epoxy-modified polyurethane self-healing elastomer.

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