Coumarin-based light / heat dual response type shape memory polyurethane as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of shape memory high-molecular polymers, and particularly relates to coumarin-based light / heat dual response type shape memory polyurethane as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out a ring-opening polymerization reaction on 2, 2-bis (4-epoxypropoxyphenyl) propane and 3-amino-1-propanol as raw materials in a liquid phase to prepare a prepolymer, and carrying out a polymerization addition reaction on the prepolymer, an isocyanate monomer and a coumarin compound as raw materials in the liquid phase under a catalytic action to prepare the coumarin-modified polyurethane. Light / heat dual response type shape memory polyurethane based on coumarin is prepared; according to the invention, the photoresponse characteristic of the coumarin compound and the temperature response characteristic of the prepolymer are ingeniously combined, so that the dual response to photostimulation and temperature stimulation is realized, and the stimulation response speed and the programming precision controllability of the coumarin-based optical / thermal dual response type shape memory polyurethane are improved.

Description

Technical Field

[0001] This invention belongs to the field of shape memory polymer technology, specifically to a coumarin-based photo / thermal dual-responsive shape memory polyurethane, its preparation method, and its application. Background Technology

[0002] Shape memory polymers (SMPs) are smart materials that temporarily change shape and then recover to their original shape under external stimuli. They can achieve reversible transformation from a temporary shape to an initial shape when triggered by external stimuli such as light, heat, and electricity. This unique shape memory effect stems from their designable molecular structure and dynamic response mechanism, making them promising for applications in high-tech fields such as biomedical engineering, aerospace, and flexible electronics.

[0003] However, traditional single-response materials (such as those with only photoresponse or only thermal response) suffer from bottlenecks such as low control efficiency, slow response rate, and difficulty in achieving remote and precise control. They cannot be "programmed" in multiple steps, which limits their application in fields such as precision medicine and flexible devices. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, this invention provides a coumarin-based photo / thermal dual-responsive shape memory polyurethane, its preparation method, and its applications. First, a prepolymer is prepared using 2,2-bis(4-epoxypropoxyphenyl)propane and 3-amino-1-propanol as raw materials. Then, a coumarin-based photo / thermal dual-responsive shape memory polyurethane is prepared using the prepolymer, isocyanate monomers, and coumarin compounds as raw materials. This invention cleverly combines the photoresponsive properties of coumarin compounds with the temperature-responsive properties of the prepolymer, achieving a dual response to both light and temperature stimuli. This improves the stimulus response speed and precise controllability of the "programming" of the coumarin-based photo / thermal dual-responsive shape memory polyurethane, overcoming the technical deficiencies of existing single-response materials.

[0005] Based on the above technical objectives, the present invention adopts the following technical solution: This invention provides a method for preparing a coumarin-based photo / thermal dual-responsive shape memory polyurethane, comprising the following steps: Using 2,2-bis(4-epoxypropoxyphenyl)propane and 3-amino-1-propanol as raw materials, a ring-opening polymerization reaction is carried out in the liquid phase to obtain a prepolymer. The prepolymer has thermal responsive properties and achieves temperature response by utilizing the glass transition temperature of the prepolymer. Subsequently, it undergoes deformation under the action of external force, and the shape is fixed by the hydrogen bonds in the prepolymer after deformation.

[0006] Using coumarin compounds, prepolymers, and isocyanate monomers as raw materials, coumarin compounds exhibit photoresponsive properties. Under ultraviolet light irradiation, the dynamic bonds of coumarin compounds are utilized to achieve deformation. In the liquid phase, under catalysis, a polymerization addition reaction is carried out to obtain a photo / thermal dual-responsive shape memory polyurethane based on coumarin.

[0007] Preferably, the mass ratio of 2,2-bis(4-epoxypropoxyphenyl)propane to 3-amino-1-propanol is 20~22:3.7~4.5.

[0008] Preferably, the conditions for the ring-opening polymerization reaction are: reaction at 120℃~140℃ for 10h~12h.

[0009] Preferably, the prepolymer has the following structural formula: Where n is 32-35; when n is less than 32, the mechanical properties of the prepolymer obtained are poor, which also results in poor mechanical properties of the coumarin-based photo / thermal dual-response shape memory polyurethane. When n is greater than 35, the strength of the prepolymer obtained is high, which also results in high strength of the coumarin-based photo / thermal dual-response shape memory polyurethane. Therefore, when n is not in the range of 32-35, the mechanical properties are not advantageous.

[0010] Preferably, the isocyanate monomer is selected from hexamethylene diisocyanate, toluene diisocyanate, or diphenylmethane diisocyanate.

[0011] Preferably, the structural formula of the coumarin compound is as follows: Where m ranges from 0 to 6. Starting from 0, as the value of m increases, the photoresponsive coumarin group becomes more independent, resulting in a faster photoresponse speed. However, if m is too large, the interaction between coumarin and the prepolymer molecular chain becomes smaller, thus it cannot effectively drive the deformation of coumarin-based photo / thermal dual-response shape memory polyurethane under ultraviolet light.

[0012] Preferably, the molar ratio of coumarin compound, prepolymer and isocyanate monomer is 1~3:1:1~3.

[0013] Preferably, the conditions for the polymerization addition reaction are: continuous stirring at 80°C to 90°C for 4 to 6 hours.

[0014] This invention also protects a coumarin-based photo / thermal dual-responsive shape memory polyurethane, prepared by the above-described method.

[0015] This invention also protects the application of coumarin-based photo / thermal dual-responsive shape memory polyurethane in the preparation of shape memory polymers.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 11. This invention first uses 2,2-bis(4-epoxypropoxyphenyl)propane and 3-amino-1-propanol as raw materials to carry out a ring-opening polymerization reaction to obtain a novel photoresponsive prepolymer. The prepolymer is prepared by the ring-opening reaction of epoxy groups and amino groups. The principle is that the nitrogen atom in the amino group (-NH2) acts as a nucleophile to attack the sterically less hindered carbon atom in the epoxy group, leading to the opening of the three-membered ring and the formation of a new CN bond. At the same time, the oxygen atom in the epoxy group accepts a proton and generates a β-hydroxyamine structure, finally yielding the structure with the following formula: The principle of the thermal response of the prepolymer is as follows: when the temperature is higher than the glass transition temperature of the prepolymer, the prepolymer can deform under the action of external force. After the deformation is completed, when the temperature is lowered to below the glass transition temperature of the prepolymer, the hydrogen bonds in the prepolymer play a role in fixing the shape. When the temperature is raised to above the glass transition temperature of the prepolymer, the prepolymer returns to its original state.

[0017] Using prepolymers, isocyanate monomers, and coumarin compounds as raw materials, a photo / thermal dual-responsive shape memory polyurethane based on coumarin is prepared by a polymerization addition reaction. The reaction principle is as follows: isocyanate (-N=C=O) and hydroxyl (-OH) undergo a nucleophilic addition reaction to form a carbamate bond (—NH−COO−). The hydroxyl groups of the prepolymer and the coumarin compound are linked together by isocyanate groups. The coumarin structure itself has photoresponsive properties. The principle of its photoresponsiveness is as follows: under ultraviolet light irradiation, the benzene ring of the coumarin compound opens, allowing the two coumarin bonds to connect and form a dimer structure. Then, it can deform under the action of external force. After the deformation is completed, when ultraviolet light is applied again, the two coumarin bonds break, and the photo / thermal dual-responsive shape memory polyurethane based on coumarin returns to its original state, at which point the original structure of the coumarin compound is formed.

[0018] 12. This invention innovatively designs a coumarin-based photo / thermal dual-responsive shape memory polyurethane, which is a coumarin-epoxy synergistic response shape memory polyurethane material (denoted as Hm-SPMUs). By copolymerizing the coumarin photosensitive unit with a thermoresponsive prepolymer containing epoxy groups, highly efficient photo / thermal dual-responsive characteristics are successfully achieved. The coumarin-based photo / thermal dual-responsive shape memory polyurethane breaks through the limitations of traditional single-stimulus responsive materials, exhibiting a synergistic effect of rapid photo and thermal response, while also possessing high regulation efficiency, fast response rate, and the ability to achieve remote and precise control. The "dynamic bonding-phase transition synergistic" molecular design strategy of this coumarin-based photo / thermal dual-responsive shape memory polyurethane not only provides new ideas for the development of high-performance smart materials, but also offers an ideal material solution for the time-temperature control fields required in precision medicine and flexible electronics.

[0019] 3. To overcome the shortcomings of existing shape memory polymers with only a single response, this invention innovatively proposes a design strategy for light / heat dual-response SMPs: by molecular-level polymerization of coumarin photosensitive units with hexamethylene diisocyanate (HDI) and specific prepolymers, a smart material system with multiple stimulus-response characteristics is successfully constructed. This system combines light and heat responses to achieve "real-time" and "point-to-point" remote and highly precise shape control of the material, breaking through the limitations of traditional single-response shape memory polymers and having significant implications. Attached Figure Description

[0020] Figure 1 Infrared spectra of H0-SPMUs from Example 1, H3-SPMUs from Example 3, H6-SPMUs from Example 5, and the prepolymer.

[0021] Figure 2 The images show the XRD patterns of H0-SPMUs from Example 1, H3-SPMUs from Example 3, H6-SPMUs from Example 5, and the prepolymer.

[0022] Figure 3 The DSC secondary cooling curves are for H0-SPMUs of Example 1, H3-SPMUs of Example 3, H6-SPMUs of Example 5, and the prepolymer.

[0023] Figure 4 The tensile properties of H0-SPMUs from Example 1, H3-SPMUs from Example 3, H6-SPMUs from Example 5, and the prepolymer are shown in the diagram.

[0024] Figure 5 The images show the UV spectra of H0-SPMUs from Example 1, H3-SPMUs from Example 3, H6-SPMUs from Example 5, and the prepolymer.

[0025] Figure 6 The images show the UV spectra of H0-SPMUs from Example 1, H3-SPMUs from Example 3, and H6-SPMUs from Example 5 before and after UV irradiation.

[0026] Figure 7 This is a diagram showing the photoresponse deformation process of H6-SPMUs in Example 5.

[0027] Figure 8 The diagram shows the thermal response deformation process of H6-SPMUs in Example 5. Detailed Implementation

[0028] The following detailed description, in conjunction with embodiments of the present invention and accompanying drawings, provides a clear and complete illustration of the technical solutions in these embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In Examples 1 to 6 of this invention, prepolymers were used as reactants, and the prepolymers were prepared according to the following steps: 20.0 g of 2,2-bis(4-epoxypropoxyphenyl)propane and 3.7 g of 3-amino-1-propanol were dissolved together in 55 mL of ultra-dry DMF and reacted at 120 °C for 12 h to obtain a pale yellow prepolymer.

[0030] .

[0031] The following examples further illustrate the technical solution of the present invention. In this invention, Hm-SPMUs (where m represents the number of coumarin C chains) are used to represent coumarin-based photo / thermal dual-responsive shape memory polyurethanes. The synthesis route is as follows: .

[0032] Example 1 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: Weigh 0.04 g of coumarin compound (m = 0) into a three-necked flask, add 5 mL of DMF, then add 1 drop of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 50 μL of hexamethylene diisocyanate (HDI), stir and react for 0.5 h; then add 8 g of prepolymer, stir continuously at 80 °C for 4 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, to obtain a coumarin-based photo / thermal dual-responsive shape memory polyurethane, denoted as H0-SPMUs.

[0033] Example 2 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: Weigh 0.05 g of coumarin compound (m = 0) into a three-necked flask, add 8 mL of DMF, then add 2 drops of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 60 μL of hexamethylene diisocyanate (HDI), stir and react for 0.5 h; then add 10 g of prepolymer, stir continuously at 80 °C for 4 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, thus obtaining a coumarin-based photo / thermal dual-responsive shape memory polyurethane.

[0034] Example 3 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: Weigh 0.04 g of coumarin compound (m = 3) into a three-necked flask, add 5 mL of DMF, then add 1 drop of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 50 μL of hexamethylene diisocyanate (HDI), stir and react for 0.5 h; then add 8 g of prepolymer, stir continuously at 80 °C for 4 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, to obtain a coumarin-based photo / thermal dual-responsive shape memory polyurethane, denoted as H3-SPMUs.

[0035] Example 4 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: Weigh 0.06 g of coumarin compound (m = 3) into a three-necked flask, add 8 mL of DMF, then add 2 drops of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 60 μL of hexamethylene diisocyanate (HDI), stir and react for 0.5 h; then add 10 g of prepolymer, stir continuously at 80 °C for 4 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, thus obtaining a coumarin-based photo / thermal dual-responsive shape memory polyurethane.

[0036] Example 5 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: Weigh 0.05 g of coumarin compound (m = 6) into a three-necked flask, add 5 mL of DMF, then add 1 drop of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 50 μL of hexamethylene diisocyanate (HDI), stir and react for 0.5 h; then add 8 g of prepolymer, stir continuously at 80 °C for 4 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, to obtain a coumarin-based photo / thermal dual-responsive shape memory polyurethane, denoted as H6-SPMUs.

[0037] Example 6 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: Weigh 0.07 g of coumarin compound (m = 6) into a three-necked flask, add 8 mL of DMF, then add 2 drops of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 60 μL of hexamethylene diisocyanate (HDI), stir and react for 0.5 h; then add 10 g of prepolymer, stir continuously at 80 °C for 4 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, thus obtaining a coumarin-based photo / thermal dual-responsive shape memory polyurethane.

[0038] Example 7 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: S1. 21.0 g of 2,2-bis(4-epoxypropoxyphenyl)propane and 4.0 g of 3-amino-1-propanol were dissolved together in 55 mL of ultra-dry DMF and reacted at 130 °C for 11 h to obtain a pale yellow prepolymer.

[0039] S2. Weigh 0.065 g of coumarin compound (m = 6) into a three-necked flask, add 6 mL of DMF, then add 3 drops of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 50 μL of toluene diisocyanate, stir and react for 0.5 h; then add 9 g of prepolymer, stir continuously at 85 °C for 6 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, to obtain a coumarin-based photo / thermal dual-responsive shape memory polyurethane.

[0040] Example 8 The preparation method of coumarin-based photo / thermal dual-responsive shape memory polyurethane includes the following steps: S1. 22.0 g of 2,2-bis(4-epoxypropoxyphenyl)propane and 4.5 g of 3-amino-1-propanol were dissolved together in 55 mL of ultra-dry DMF and reacted at 140 °C for 10 h to obtain a pale yellow prepolymer.

[0041] S2. Weigh 0.07 g of coumarin compound (m = 6) into a three-necked flask, add 7 mL of DMF, then add 3 drops of dibutyltin dilaurate (catalyst), stir at 60 °C for 15 min, then add 50 μL of diphenylmethane diisocyanate, stir and react for 0.5 h; then add 10 g of prepolymer, stir continuously at 90 °C for 5 h, then pour into a polytetrafluoroethylene mold, place in a forced-air drying oven at 60 °C, and dry to form a film, to obtain a coumarin-based photo / thermal dual-responsive shape memory polyurethane.

[0042] Examples 1 to 6 of this invention all yielded coumarin-based photo / thermal dual-response shape memory polyurethanes with excellent photo / thermal dual-response properties. The following research uses the coumarin-based photo / thermal dual-response shape memory polyurethanes from Examples 1, 3, and 5 as examples, and the specific research methods and results are shown below: Figure 1 The figures show the infrared spectra of H0-SPMUs, H3-SPMUs, H6-SPMUs, and the prepolymer. The figures also show that at 2850 cm⁻¹... -1 ~2960cm -1 The absorption peak at 3200 cm⁻¹ is the stretching vibration peak of CH (=CH); -1 ~3600cm -1 The broad absorption peak at 2868 cm⁻¹ is considered to be the stretching vibration peak of -OH; the characteristic absorption peaks of the stretching vibrations of CH and C=O are at 2868 cm⁻¹. -1 ~2921cm -1 and 1717cm -1 1660cm -1 The absorption at this site is attributed to the C=C stretching vibration of coumarin in Hm-SPMUs.

[0043] Further investigation of the crystal phase structure of coumarin-based photo / thermal dual-responsive shape memory polyurethane and prepolymers was conducted using X-ray diffraction, with results as follows: Figure 2 As shown; H0-SPMUs, H3-SPMUs, H6-SPMUs and the prepolymer are in wide-angle region 2 θ =10 o ~40 o The prepolymer exhibits diffuse diffraction peaks within the range, indicating that the polymer chains itself have high disorder and are amorphous. When photoresponsive groups of coumarin compounds are introduced, the disordered arrangement of the molecular chains will further increase, so it only shows diffuse broad peaks.

[0044] Figure 3 The graph shows the secondary cooling curves of H0-SPMUs, H3-SPMUs, H6-SPMUs and prepolymers. It can be observed from the graph that there are certain differences in the glass transition temperature (Tg) of Hm-SPMUs. When the carbon chain of the coumarin compound backbone increases, it is more conducive to the formation of a dimer structure of coumarin, thereby increasing the intermolecular forces and the glass transition temperature of Hm-SPMUs also increases slightly.

[0045] Depend on Figure 4 The stress-strain diagrams show significant variations in the tensile strength and elongation at break of Hm-SPMUs prepared from coumarin compounds with different carbon contents. With increasing carbon content in the coumarin compounds, the tensile strength of the Hm-SPMUs films gradually increases, while the elongation at break initially increases and then decreases. The increase in tensile strength is mainly related to the interactions between coumarin compounds, which enhances intermolecular forces, thus increasing strength. However, with the growth of the carbon chain, the mobility of coumarin compounds increases, leading to the formation of more dimer structures, which disrupts the ordered structure of Hm-SPMUs and results in a decrease in elongation at break.

[0046] pass Figure 5 The UV-Vis spectrum clearly shows that the absorption peaks of H6-SPMUs containing 6-carbon coumarin compounds exhibit a red shift compared to those of other Hm-SPMUs containing different 6-carbon coumarin compounds. This is because the intermolecular interactions / close packing of H6-SPMUs containing 6-carbon coumarin compounds are relatively strong.

[0047] This invention also measured the UV-Vis spectra of H6-SPMUs containing a 6-carbon coumarin compound under different UV irradiation times (365 nm, 0 s, 30 s, 60 s, 90 s, 120 s, 150 s, 180 s, 300 s) to monitor the photodimerization and crosslinking response process of H6-SPMUs under UV irradiation. The results are as follows: Figure 6 As shown, the characteristic absorption peak of coumarin is at 335 nm. By irradiating it with ultraviolet light for different durations, it was found that the intensity of the absorption peak continuously decreases as the ultraviolet light irradiation time continues to increase. This indicates that the coumarin unit undergoes photodimerization under 365 nm ultraviolet light irradiation, and the change is significant within a short time interval of tens of seconds. This further proves that coumarin compounds have a fast photostimulation response speed.

[0048] Depend on Figure 7It is evident that the deformation of the H6-SPMUs thin film under ultraviolet light stimulation can be precisely controlled. By irradiating different locations of the film with ultraviolet light, a fixed deformation is induced. Further light stimulation can then be applied as needed to "program" the shape "at specific times" and "at specific locations." Based on its photoresponse characteristics, a bendable deformation pattern was designed, and its photoresponse process is as follows: Figure 7 As shown.

[0049] Depend on Figure 8 It is evident that H6-SPMUs exhibit rapid thermal response characteristics. To better demonstrate its stimulus-response process, the H6-SPMUs film was manually fixed into a specific shape and then placed in an environment of 45°C. Under temperature stimulation, the H6-SPMUs quickly returned to their initial shape. Furthermore, after imprinting a three-dimensional shape onto its surface using a mold and placing it in the same 45°C environment, the imprinted pattern information was quickly and completely erased.

[0050] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

Claims

1. A method for preparing a coumarin-based photo / thermal dual-responsive shape memory polyurethane, characterized in that, Includes the following steps: Using 2,2-bis(4-epoxypropoxyphenyl)propane and 3-amino-1-propanol as raw materials, a ring-opening polymerization reaction was carried out in the liquid phase. The nitrogen atom in the amino group acted as a nucleophile to attack the carbon atom in the epoxy group, causing the three-membered ring to open and form a new CN bond. At the same time, the oxygen atom of the epoxy group accepted a proton to generate a β-hydroxyamine structure, thus obtaining the prepolymer. Using coumarin compounds, prepolymers, and isocyanate monomers as raw materials, a polymerization addition reaction is carried out in the liquid phase under catalysis. Isocyanate and hydroxyl groups form urethane bonds through nucleophilic addition reaction, and the hydroxyl groups of the prepolymer and the coumarin compound are linked together through isocyanate groups to obtain a coumarin-based light / heat dual-responsive shape memory polyurethane.

2. The method for preparing coumarin-based photo / thermal dual-responsive shape memory polyurethane according to claim 1, characterized in that, The mass ratio of 2,2-bis(4-epoxypropoxyphenyl)propane to 3-amino-1-propanol is 20~22:3.7~4.

5.

3. The method for preparing coumarin-based photo / thermal dual-responsive shape memory polyurethane according to claim 1, characterized in that, The conditions for the ring-opening polymerization reaction are: reaction at 120℃~140℃ for 10h~12h.

4. The method for preparing coumarin-based photo / thermal dual-responsive shape memory polyurethane according to claim 1, characterized in that, The structural formula of the prepolymer is , where n is 32-35.

5. The method for preparing coumarin-based photo / thermal dual-responsive shape memory polyurethane according to claim 1, characterized in that, The isocyanate monomers are selected from hexamethylene diisocyanate, toluene diisocyanate, or diphenylmethane diisocyanate.

6. The method for preparing coumarin-based photo / thermal dual-response shape memory polyurethane according to claim 1, characterized in that, The structural formula of coumarin compounds is , where m is 0~6.

7. The method for preparing coumarin-based photo / thermal dual-response shape memory polyurethane according to claim 1, characterized in that, The molar ratio of coumarin compounds, prepolymers and isocyanate monomers is 1~3:1:1~3.

8. The method for preparing coumarin-based photo / thermal dual-response shape memory polyurethane according to claim 1, characterized in that, The conditions for the polymerization addition reaction are: continuous stirring at 80°C to 90°C for 4 to 6 hours.

9. A coumarin-based photo / thermal dual-responsive shape memory polyurethane, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the coumarin-based photo / thermal dual-responsive shape memory polyurethane of claim 9 in the preparation of shape memory polymers.

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