Near-infrared light responsive self-healing polyurethane elastomer and preparation and application thereof

Abstract

The application discloses near-infrared light response self-repairing polyurethane elastomer and preparation and application thereof, and a method comprises the following steps: reacting polyhydric alcohol, polyisocyanate, a catalyst and a chain extender to obtain polyurethane elastomer; ultrasonic dispersion of photothermal nanoparticles in a dispersant to obtain a photothermal nanoparticle dispersion; re-dissolving the polyurethane elastomer in a solvent, and then mixing the polyurethane elastomer with the dispersion to obtain a mixture; and drying the mixture and then pressing and forming to obtain the near-infrared light response self-repairing polyurethane elastomer. The photothermal nanoparticles are subjected to gradient solvent dispersion treatment, the size of the photothermal nanoparticles is reduced, and the photothermal nanoparticles contain functional groups on the surface, so that the photothermal nanoparticles are uniformly and stably dispersed in the polyurethane elastomer; the amide groups contained in the chain extender can form strong hydrogen bond effects between the polyisocyanate and the polyhydric alcohol, so that the number of bonding sites in the self-repairing process is increased; and under the synergistic effect of the photothermal nanoparticles, near-infrared light response and rapid and accurate self-repairing of the polyurethane elastomer are realized.

Description

Technical Field

[0001] This invention belongs to the field of functional composite materials technology, specifically relating to a near-infrared light-responsive self-healing polyurethane elastomer and its preparation and application. Background Technology

[0002] Polyurethane elastomers are polymeric materials with excellent mechanical properties and good processability. They are mainly composed of polyisocyanates, oligomeric polyols, and chain extenders. The excellent stretchability, resilience, and abrasion resistance of polyurethane elastomers make them widely used in specialty engineering plastics, smart wearables, and other fields.

[0003] The basic structure of polyurethane consists of "soft" and "hard" segments. The hard segments are composed of polyisocyanates and chain extenders, while the soft segments are composed of oligomeric polyols. The unique separation of these "soft" and "hard" segments endows it with outstanding mechanical properties. Furthermore, functionalized polyurethane elastomers, such as those exhibiting smart responsiveness, self-healing properties, and electron transport capabilities, can be obtained by modifying the composition of these segments. However, functionalizing polyurethane through chemical modification increases the difficulty of preparing polyurethane elastomers, and introducing new functional groups or components can affect the mechanical properties of polyurethane elastomers.

[0004] Doping polyurethane elastomers with nanoparticles is an effective way to solve the above problems. The specific advantages are: (1) Nanoparticles can provide energy dissipation sites in the polyurethane system, further improving the mechanical properties of the polyurethane elastomer; (2) The inherent properties of nanoparticles can functionalize polyurethane elastomers; and (3) Composite materials can be prepared through physical blending. However, the poor compatibility between nanoparticles and polyurethane elastomers greatly affects the performance of composite polyurethane elastomers. How to improve the compatibility between nanoparticles and polyurethane elastomers to obtain functionalized polyurethane elastomers has become an urgent problem to be solved. Summary of the Invention

[0005] In view of the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a method for preparing a near-infrared light-responsive self-healing polyurethane elastomer.

[0006] Another object of the present invention is to provide a near-infrared light-responsive self-healing polyurethane elastomer prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above-mentioned near-infrared light-responsive self-healing polyurethane elastomer.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A method for preparing a near-infrared light-responsive self-healing polyurethane elastomer includes the following steps:

[0010] (1) Polyurethane elastomer is obtained by reacting polyol, polyisocyanate, catalyst and chain extender;

[0011] (2) The photothermal nanoparticles were ultrasonically dispersed in a dispersant to obtain a photothermal nanoparticle dispersion.

[0012] (3) The polyurethane elastomer from step (1) is redissolved in a solvent and then mixed with the photothermal nanoparticle dispersion from step (2) to obtain a mixture.

[0013] (4) After drying the mixture, press it into shape to obtain the near-infrared light-responsive self-healing polyurethane elastomer.

[0014] Preferably, step (1) specifically includes: stirring polyol and polyisocyanate at a molar ratio of 1:(0.1-15) at 70-90°C for 1-5 hours, then adding 0.01-0.5 wt% of a catalyst to the reactants and continuing the reaction for 1-10 hours to obtain a prepolymer; then adding a chain extender at a molar ratio of 1:(0.1-10) to the polyol to the prepolymer system, and continuing the reaction in a solvent at 70-90°C for 5-24 hours to obtain a polyurethane elastomer.

[0015] More preferably, step (1) specifically includes: stirring polyol and polyisocyanate at a molar ratio of 1:1 at 80°C for 1 h, then adding 0.1 wt% of the reactant catalyst and continuing the reaction for 3 h to obtain a prepolymer; then adding a chain extender with a molar ratio of 1:3 to the polyol to the prepolymer system, and continuing the reaction in a solvent at 80°C for 20 h to obtain a polyurethane elastomer.

[0016] Preferably, the solvent is at least one selected from acetone, toluene, N,N-dimethylformamide, dimethylacetamide, and dimethyl sulfoxide.

[0017] Preferably, the polyol is polyethylene glycol, polytetrahydrofuran glycol, polyester-block-polyether α,ω-diol, or polycaprolactone diol, more preferably polycaprolactone diol.

[0018] Preferably, the polyisocyanate is isophorone diisocyanate, terephthalic diisocyanate, trimethylhexane diisocyanate, or naphthalene diisocyanate, and more preferably isophorone diisocyanate.

[0019] Preferably, the catalyst is dibutyltin dilaurate.

[0020] Preferably, the chain extender has the structure shown in formula (I):

[0021]

[0022] In the formula, n = 1 to 20, preferably n = 1 to 5; when R is an alkane chain, the substituent at any position is -NH, -NH2, -COOH, -OH or -COO-.

[0023] More preferably, the chain extender is N,N-bis(2-hydroxyethyl)oxalamide, i.e., R in formula (I) is -(CH2). n - The case where n = 1.

[0024] Preferably, the polyurethane elastomer has the structure shown in formula (II):

[0025]

[0026] In the formula, x = 10 to 50, preferably x = 30 to 35. The compound shown in formula (II) has been disclosed in the article (Guo R, Zhang Q, Wu Y, et al. Extremely Strong and Tough Biodegradable Poly(urethane) Elastomers with Unprecedented Crack Tolerance via Hierarchical Hydrogen-Bonding Interactions[J]. Advanced Materials, 2023: 2212130.).

[0027] Preferably, the dispersant is ethanol, N,N-dimethylformamide, and deionized water.

[0028] Preferably, the photothermal nanoparticles in step (2) are ultrasonically dispersed using a gradient solvent dispersion method, which specifically includes the following steps:

[0029] S1. Prepare a 0.01-1 g / mL ethanol dispersion of photothermal nanoparticles and sonicate for 1-12 h to obtain a photothermal nanoparticle / ethanol dispersion system.

[0030] S2. Add deionized water to the photothermal nanoparticle / ethanol dispersion system and continue sonication for 1 to 12 hours to obtain the photothermal nanoparticle / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:(1 to 1000).

[0031] S3. Add N,N-dimethylformamide to the photothermal nanoparticle / ethanol / deionized water dispersion system and continue sonication for 1-12 hours to obtain a photothermal nanoparticle dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:(1-1000):(1-1000).

[0032] More preferably, the ultrasound time in steps S1, S2, and S3 is 5 hours.

[0033] Preferably, the photothermal nanoparticles are at least one of gallium-based liquid metals Ga, GaIn, or GaInSn.

[0034] Preferably, the content of photothermal nanoparticles in the mixture in step (3) is 1 to 60 wt% of polyurethane elastomer, more preferably 5 wt%; the mixing is carried out by stirring for 1 to 12 hours to achieve uniform mixing.

[0035] Preferably, the drying temperature in step (4) is 60-100°C and the drying time is 24-48h, more preferably 48h.

[0036] Preferably, the temperature of the pressure plate in step (4) is 100-200°C, more preferably 180°C.

[0037] A near-infrared light-responsive self-healing polyurethane elastomer is prepared by the above-described preparation method.

[0038] The aforementioned near-infrared light-responsive self-healing polyurethane elastomer can be applied to fields such as flexible wearable devices, human-computer interaction interfaces, and electronic sensor devices.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] (1) The present invention disperses photothermal nanoparticles by gradient solvent method, which can obtain photothermal nanoparticles with reduced size and functional groups on the surface. Due to the size effect and the weak interaction between the surface functional groups and the polyurethane elastomer, the photothermal nanoparticles after dispersion treatment are uniformly and stably dispersed in the polyurethane elastomer. Under near-infrared light conditions, they provide photothermal conversion sites and promote the migration of molecular chains of polyurethane elastomer, thereby achieving good self-healing performance.

[0041] (2) The amide groups contained in the chain extender used in this invention can form strong hydrogen bonds with polyisocyanates and polyols, thereby increasing the binding sites in the self-repair process. Under the synergistic effect of photothermal nanoparticles, the prepared composite material can be triggered by near-infrared light to migrate polyurethane molecular chains and photothermal nanoparticles to the damaged interface at the same time, which not only realizes near-infrared light response, but also promotes the rapid and precise self-repair of polyurethane elastomer. Attached Figure Description

[0042] Figure 1 The infrared spectra of the polyurethane elastomers prepared in Examples 1, 5, and 6 are shown.

[0043] Figure 2The infrared spectra of GaInSn prepared in Example 7 after gradient solvent dispersion treatment (Treated GaInSn) and GaInSn without gradient solvent dispersion treatment (Untreated GaInSn) are shown.

[0044] Figure 3 The particle size distribution diagrams are shown for GaInSn prepared in Example 7 after gradient solvent dispersion treatment and GaInSn treated only by N,N-dimethylformamide dispersion.

[0045] Figure 4 The image shows a comparison of the compatibility of the two GaInSn / polyurethane mixtures prepared in Example 7.

[0046] Figure 5 The results show the self-healing performance test results of the near-infrared light-responsive self-healing polyurethane elastomer prepared in Example 7.

[0047] Figure 6 The stress-strain curves of the near-infrared light-responsive self-healing polyurethane elastomer prepared in Example 7 before and after self-healing are shown. Detailed Implementation

[0048] The following embodiments are provided to further illustrate the present invention, but are not intended to limit the invention. It should be noted that the embodiments are only for further illustration and should not be construed as limiting the scope of protection of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make some non-essential improvements and adjustments based on the above description of the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0049] All raw materials involved in this invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be used as a reference.

[0050] Example 1

[0051] Preparation of polyurethane elastomer IPDI-PCL-BHO:

[0052] Polycaprolactone diol and isophorone diisocyanate were added to a flask at a molar ratio of 1:1 and stirred at 80°C for 1 hour. Then, 0.1 wt% of dibutyltin dilaurate was added to the reactants, and the reaction continued for 3 hours to obtain a prepolymer. Next, N,N-bis(2-hydroxyethyl)oxalamide, a chain extender with a molar ratio of 1:3 to polycaprolactone diol, was added to the prepolymer system, and the reaction was continued at 80°C for 20 hours in N,N-dimethylformamide to obtain the polyurethane elastomer shown in the following formula:

[0053]

[0054] In the formula, x = 35, denoted as IPDI-PCL-BHO, and its infrared spectrum is as follows: Figure 1 As shown.

[0055] Example 2

[0056] This embodiment uses the same method as Example 1 to synthesize polyurethane elastomer: polycaprolactone diol and isophorone diisocyanate are added to a flask at a molar ratio of 1:2, stirred at 80°C for 1 h, and then 0.1 wt% of dibutyltin dilaurate is added to the reactants and the reaction continues for 3 h to obtain a prepolymer; then, N,N-bis(2-hydroxyethyl)oxalamide, a chain extender with a molar ratio of 1:2 to polycaprolactone diol, is added to the prepolymer system, and the reaction continues in N,N-dimethylformamide at 80°C for 20 h to obtain the polyurethane elastomer shown in the following formula:

[0057]

[0058] In the formula, x = 32.

[0059] Example 3

[0060] This embodiment uses the same method as Example 1 to synthesize polyurethane elastomer: polycaprolactone diol and isophorone diisocyanate are added to a flask at a molar ratio of 1:3, stirred at 80°C for 1 h, and then 0.1 wt% of dibutyltin dilaurate is added to the reactants and the reaction continues for 3 h to obtain a prepolymer; then, N,N-bis(2-hydroxyethyl)oxalamide, a chain extender with a molar ratio of 1:1 to polycaprolactone diol, is added to the prepolymer system, and the reaction continues in N,N-dimethylformamide at 80°C for 20 h to obtain the polyurethane elastomer shown in the following formula:

[0061]

[0062] In the formula, x = 30.

[0063] Example 4

[0064] This embodiment uses the same method as Example 1 to synthesize polyurethane elastomer: polycaprolactone diol and isophorone diisocyanate are added to a flask at a molar ratio of 1:4, stirred at 80°C for 1 h, and then 0.1 wt% of dibutyltin dilaurate is added to the reactants and the reaction continues for 3 h to obtain a prepolymer; then, N,N-bis(2-hydroxyethyl)oxalamide, a chain extender with a molar ratio of 1:0.5 to polycaprolactone diol, is added to the prepolymer system, and the reaction continues in N,N-dimethylformamide at 80°C for 20 h to obtain the polyurethane elastomer shown in the following formula:

[0065]

[0066] In the formula, x = 28.

[0067] Example 5

[0068] Preparation of polyurethane elastomer IPDI-PTMEG-BHO:

[0069] Polytetrahydrofuran diol and isophorone diisocyanate were added to a flask at a molar ratio of 1:1 and stirred at 80°C for 1 hour. Then, 0.1 wt% of dibutyltin dilaurate was added to the reactants, and the reaction continued for 3 hours to obtain a prepolymer. Next, N,N-bis(2-hydroxyethyl)oxalamide, a chain extender with a molar ratio of 1:3 to polycaprolactone diol, was added to the prepolymer system, and the reaction continued in N,N-dimethylformamide at 80°C for 20 hours to obtain a polyurethane elastomer, designated IPDI-PTMEG-BHO. Its infrared spectrum is shown below. Figure 1 As shown.

[0070] Example 6

[0071] Preparation of polyurethane elastomer IPDI-PEG-BHO:

[0072] Polyethylene glycol and isophorone diisocyanate were added to a flask at a molar ratio of 1:1 and stirred at 80°C for 1 hour. Then, 0.1 wt% of dibutyltin dilaurate was added to the reactants, and the reaction continued for 3 hours to obtain a prepolymer. Next, N,N-bis(2-hydroxyethyl)oxalamide, a chain extender with a molar ratio of 1:3 to polycaprolactone glycol, was added to the prepolymer system, and the reaction continued in N,N-dimethylformamide at 80°C for 20 hours to obtain a polyurethane elastomer, denoted as IPDI-PEG-BHO, whose infrared spectrum is shown below. Figure 1 As shown.

[0073] Example 7

[0074] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0075] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0076] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0077] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0078] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:1:1.

[0079] A portion of the GaInSn dispersion treated with gradient solvent was dried (Treated GaInSn); a separate small amount of gallium-based liquid metallic GaInSn was directly dried (Untreated GaInSn); the dried samples were characterized using infrared spectroscopy, and the characterization results are as follows: Figure 2 As shown in the figure, compared to untreated GaInSn, treated GaInSn exhibits higher growth rates at 1240 cm⁻¹. -1 The appearance of new infrared peaks indicates the presence of new functional groups on the GaInSn surface treated with gradient solvent dispersion.

[0080] For comparison, gallium-based liquid metal GaInSn was directly added to N,N-dimethylformamide to prepare a 0.5 g / mL N,N-dimethylformamide dispersion. The dispersion was then sonicated at room temperature for 5 h to obtain a GaInSn / N,N-dimethylformamide dispersion system (GaInSn / DMF). A portion of the GaInSn dispersion treated with gradient solvents was taken, and the particle size of the GaInSn / DMF and treated GaInSn samples was measured using a laser particle size analyzer. The particle size test results are as follows: Figure 3 As shown in the figure, the average particle size of treated GaInSn is reduced compared to GaInSn / DMF. The size effect and surface functional groups of the dispersed GaInSn further enhance its dispersibility in polyurethane elastomers.

[0081] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion (Treated GaInSn) prepared by the above gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 1wt% of the polyurethane elastomer; after stirring, the mixture (Treated) was degassed under vacuum for 30min, and then transferred to a vacuum oven to dry at 80℃ for 48h.

[0082] As a comparison, untreated GaInSn was used to replace treated GaInSn to obtain another set of mixtures (untreated). The states of the two sets of mixtures were recorded immediately after preparation and after standing for 1 day, 1 week, and 2 weeks, respectively. Figure 4 As shown in the figure, GaInSn treated with the concentration gradient method has better compatibility with the polyurethane solution, which promotes its uniform and stable dispersion in the polyurethane elastomer.

[0083] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0084] The prepared near-infrared photoresponsive self-healing polyurethane elastomer was incised with a blade and then placed 30 cm away from a near-infrared lamp for 5 minutes to observe its self-healing status. The repair effect was as follows: Figure 5 As shown in the figure: Original represents the initial state of the black film of the composite material, Cut represents the state where the black film is cut through by a blade, and Healed represents its self-healing state. The figure shows that the gallium-based liquid metal / polyurethane elastomer composite material prepared by this invention has near-infrared response characteristics. It can be triggered by near-infrared light to simultaneously migrate polyurethane molecular chains and gallium-based liquid metal to the damaged interface, achieving rapid and precise self-healing.

[0085] To evaluate the self-healing effect, the stress-strain curves of the prepared near-infrared responsive self-healing polyurethane elastomer before and after self-healing were characterized using a tensile testing machine. The results are as follows: Figure 6 As shown in the figure, the fracture strain and stress before repair (Original) were 694% and 8.85 MPa, respectively, and the fracture strain and stress after repair (Healed) were 614% and 6.68 MPa, respectively. The repair rates of strain and stress were 88.47% and 75.48%, respectively.

[0086] Example 8

[0087] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0088] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0089] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0090] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:1.

[0091] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:1.

[0092] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the above gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 1wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0093] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0094] Example 9

[0095] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0096] (1) Preparation of Ga dispersion by gradient solvent dispersion method

[0097] S1. Liquid metal Ga was added to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and ultrasonicated at room temperature for 5 h to obtain a Ga / ethanol dispersion system;

[0098] S2. Add deionized water to the Ga / ethanol dispersion system and continue sonication at room temperature for 5 hours to obtain the Ga / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0099] S3. Add N,N-dimethylformamide to the Ga / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain a Ga dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:2.

[0100] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the Ga dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the Ga content was 1wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0101] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0102] Example 10

[0103] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0104] (1) Preparation of GaIn dispersion by gradient solvent dispersion method

[0105] S1. Add gallium-based liquid metal GaIn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaIn / ethanol dispersion system;

[0106] S2. Add deionized water to the GaIn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0107] S3. Add N,N-dimethylformamide to the GaIn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaIn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:2.

[0108] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaIn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 1wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0109] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0110] Example 11

[0111] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0112] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0113] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0114] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0115] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:3.

[0116] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 2wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven to dry at 80℃ for 48h.

[0117] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0118] Example 12

[0119] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0120] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0121] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0122] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0123] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:4.

[0124] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 4wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0125] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0126] Example 13

[0127] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0128] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0129] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0130] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:3.

[0131] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:3:2.

[0132] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 5wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0133] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0134] Example 14

[0135] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0136] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0137] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0138] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0139] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:5.

[0140] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 7wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0141] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0142] Example 15

[0143] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0144] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0145] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0146] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0147] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:6.

[0148] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 9wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven to dry at 80℃ for 48h.

[0149] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0150] Example 16

[0151] Preparation of near-infrared light-responsive self-healing polyurethane elastomers:

[0152] (1) Preparation of GaInSn dispersion by gradient solvent dispersion method

[0153] S1. Add gallium-based liquid metal GaInSn to ethanol to prepare an ethanol dispersion of 0.5 g / mL, and sonicate at room temperature for 5 h to obtain a GaInSn / ethanol dispersion system;

[0154] S2. Add deionized water to the GaInSn / ethanol dispersion system and continue to sonicate at room temperature for 5 hours to obtain the GaInSn / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:2.

[0155] S3. Add N,N-dimethylformamide to the GaInSn / ethanol / deionized water dispersion system and continue to sonicate at room temperature for 5 hours to obtain GaInSn dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:2:7.

[0156] (2) The polyurethane elastomer IPDI-PCL-BHO prepared in Example 1 was redissolved in N,N-dimethylformamide, and the GaInSn dispersion prepared by the gradient solvent dispersion method was added and stirred for 5h, wherein the GaInSn content was 10wt% of the polyurethane elastomer; after stirring, the mixture was degassed under vacuum for 30min, and then transferred to a vacuum oven at 80℃ for 48h.

[0157] (3) The dried product is added into a mold and pressed at 180°C to obtain a black film, which is a near-infrared light-responsive self-healing polyurethane elastomer.

[0158] The above description, in conjunction with specific embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of this application.

Claims

1. A method for preparing a near-infrared light-responsive self-healing polyurethane elastomer, characterized in that, Includes the following steps: (1) Polyurethane elastomer is obtained by reacting polyol, polyisocyanate, catalyst and chain extender; (2) The photothermal nanoparticles are ultrasonically dispersed in a dispersant to obtain a photothermal nanoparticle dispersion; (3) The polyurethane elastomer from step (1) is redissolved in a solvent and then mixed with the photothermal nanoparticle dispersion from step (2) to obtain a mixture; (4) The near-infrared light-responsive self-healing polyurethane elastomer is obtained by drying the mixture and pressing it into shape. The chain extender has the structure shown in formula (I): ； Formula (I) In the formula, n = 1~20; when R is an alkane chain, the substituents at any position are -NH2, -COOH, or -OH; The photothermal nanoparticles in step (2) are ultrasonically dispersed using a gradient solvent dispersion method; the photothermal nanoparticles are at least one of gallium-based liquid metals Ga, GaIn, or GaInSn. The gradient solvent dispersion method specifically includes the following steps: S1. Prepare a 0.01~1g / mL ethanol dispersion of photothermal nanoparticles and sonicate for 1~12h to obtain a photothermal nanoparticle / ethanol dispersion system. S2. Add deionized water to the photothermal nanoparticle / ethanol dispersion system and continue sonication for 1~12h to obtain the photothermal nanoparticle / ethanol / deionized water dispersion system, wherein the volume ratio of ethanol to deionized water is 1:(1~1000). S3. Add N,N-dimethylformamide to the photothermal nanoparticle / ethanol / deionized water dispersion system and continue sonication for 1~12h to obtain a photothermal nanoparticle dispersion, wherein the volume ratio of ethanol, deionized water and N,N-dimethylformamide is 1:(1~1000):(1~1000). The content of photothermal nanoparticles in the mixture in step (3) is 1~60wt% of polyurethane elastomer.

2. The method for preparing the near-infrared light-responsive self-healing polyurethane elastomer according to claim 1, characterized in that, Step (1) specifically includes: stirring polyol and polyisocyanate at a molar ratio of 1:(0.1~15) at 70~90℃ for 1~5h, then adding 0.01~0.5wt% of catalyst to the reactants and continuing the reaction for 1~10h to obtain a prepolymer; then adding a chain extender with a molar ratio of 1:(0.1~10) to the polyol to the prepolymer system, and continuing the reaction in a solvent at 70~90℃ for 5~24h to obtain a polyurethane elastomer; The solvent is at least one selected from acetone, toluene, N,N-dimethylformamide, dimethylacetamide, and dimethyl sulfoxide.

3. The method for preparing the near-infrared light-responsive self-healing polyurethane elastomer according to claim 1, characterized in that, The polyol is polyethylene glycol, polytetrahydrofuran glycol, polyester-block-polyether α,ω-diol, or polycaprolactone diol; the polyisocyanate is isophorone diisocyanate, terephthalic diisocyanate, naphthalene diisocyanate, or trimethylhexane diisocyanate; and the catalyst is dibutyltin dilaurate.

4. The method for preparing the near-infrared light-responsive self-healing polyurethane elastomer according to claim 3, characterized in that, The polyol is polycaprolactone diol; the polyisocyanate is isophorone diisocyanate; the chain extender is N,N'-bis(2-hydroxyethyl)oxalamide; the polyurethane elastomer has the structure shown in formula (II): ； Equation (II) In the formula, x = 10~50.

5. The method for preparing the near-infrared light-responsive self-healing polyurethane elastomer according to claim 1, characterized in that, The mixing in step (3) involves stirring for 1 to 12 hours to ensure uniform mixing.

6. The method for preparing the near-infrared light-responsive self-healing polyurethane elastomer according to claim 1, characterized in that, The drying temperature in step (4) is 60~100℃ and the time is 24~48h; the temperature of the pressing plate is 100~200℃.

7. The near-infrared light-responsive self-healing polyurethane elastomer prepared by the preparation method of the near-infrared light-responsive self-healing polyurethane elastomer according to any one of claims 1 to 6.

8. The application of the near-infrared light-responsive self-healing polyurethane elastomer of claim 7 in the fields of flexible wearable devices, human-computer interaction interfaces, and electronic sensor devices.

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