Photosensitive functional monomer and method for preparing photocuring 3D printing polyurethane elastomer by using same

Abstract

The invention discloses a photosensitive functional monomer and a method for preparing a photocuring 3D printing polyurethane elastomer by using the photosensitive functional monomer, and relates to a self-repairing polymer functional material. The technical problems that an existing self-repairing polyurethane elastomer prepared through photocuring 3D printing is low in repairing efficiency and poor in mechanical performance are solved. The chemical structural formula of the functional monomer is # imgabs0 #, wherein m is 1, 2, 3 or 4; r is # imgabs 1 # and is obtained by synthesizing an intermediate from 1, 4-benzene diboronic acid, 1, 2, 4-butantriol, water and anhydrous magnesium sulfate and then reacting the intermediate with acrylic acid-2-isocyano ethyl ester. A photosensitive functional monomer, a photosensitive resin monomer, a reactive diluent and a photoinitiator are mixed into slurry for 3D printing, the polyurethane elastomer is obtained, the tensile strength of the polyurethane elastomer reaches 3-8.6 MPa, the visible light transmittance reaches 85%, the polyurethane elastomer can be 100% healed after being heated at 80 DEG C, and the polyurethane elastomer also has a self-repairing function at room temperature and can be used in the field of 3D printing.

Description

Technical Field

[0001] The invention relates to a self-repairing polymer functional material and a method for preparing a 3D-printed polyurethane elastomer by using the same. Background Art

[0002] 3D printing, also known as additive manufacturing, is an emerging rapid prototyping technology that has been greatly favored in many fields such as biomedicine, aerospace, and smart devices. Among them, light-curing 3D printing technology has gradually become a research hotspot due to its high printing resolution and high efficiency, and its ability to achieve micro-size and complex structure molding, and has good development prospects.

[0003] Polyurethane elastomers are widely used in many fields due to their unique molecular structure. However, during use, they are inevitably subject to physical damage caused by light, heat or mechanical stimulation, which ultimately leads to a significant reduction in their service life and reliability. On the other hand, the treatment of waste polyurethane elastomers (including landfill or incineration) usually leads to a large waste of resources and environmental pollution. Self-healing polyurethane elastomers that can be photocured 3D printed are a new type of material that can self-repair after being damaged. Due to this special function, self-healing polyurethane elastomers that can be photocured 3D printed have shown great potential in the fields of coatings and flexible electronic devices.

[0004] Boric acid ester is a dynamic covalent bond with a unique combination of high thermodynamic stability and kinetic adjustability, and the bond dissociation energy of the boric acid ester bond is -124kcal / mol. The higher bond dissociation energy can give the polyurethane elastomer higher strength and thermal stability. In the Chinese patent "A method for preparing a self-repairing photocurable reconfigurable system based on boric acid ester bond exchange" with application number CN201811583121.8, a difunctional thiol monomer containing a boric acid ester bond is prepared by a one-step reaction, and a thiol-ene photoinitiated click reaction is carried out with a multifunctional double bond monomer to obtain a cross-linked system containing a boric acid ester bond. Since the boric acid ester bond can undergo an exchange reaction when heated, the cross-linked system after photocuring has a certain plasticity when heated, and thus can achieve self-repair and repeated reprocessing. However, the materials used in this method are solid or high-viscosity fluids, which need to be diluted with an inert organic solvent, and contain thiol raw materials with a strong taste, so it is not suitable for photocuring 3D printing. In 2020, the University of Science and Technology of China published a polyurethane elastomer containing borate bonds in the article "Preparation and Performance Research of Self-Healing Polyurethane Materials". The tensile strength of the polyurethane elastomer is 7.73MPa. After 24 hours of repair at room temperature under the stimulation of water, the healing efficiency based on toughness is only 62.03%, and after 24 hours of repair at room temperature in air, the healing efficiency is only 2.56%. The tensile strength of the photocurable borate-based polyurethane is 288kPa, and the healing efficiency is only 80.8% after 24 hours of repair at room temperature. Summary of the invention

[0005] The present invention aims to solve the technical problems of low repair efficiency and poor mechanical properties of self-healing polyurethane elastomers prepared by existing photocuring 3D printing, and provides a photosensitive functional monomer and a method for preparing photocuring 3D printed polyurethane elastomers using the same. The introduction of the photosensitive functional monomer containing borate bonds of the present invention enables the polyurethane elastomer to achieve high-precision photocuring 3D printing of complex configurations, and gives it excellent self-healing properties under mild conditions. At the same time, the introduction of dynamic borate bonds enables the polyurethane elastomer to achieve repeated molding processing by hot pressing.

[0006] The chemical formula of the photosensitive functional monomer of the present invention is:

[0007] Where m is 1, 2, 3 or 4; R is

[0008]

[0009] The photosensitive functional monomer of the present invention contains dynamic borate bonds. Under mild room temperature or heating conditions, ester exchange reactions occur between the borate bonds, and hydrogen bonds can be broken and reorganized. The combination of the two can give the cross-linked polymer excellent self-repairing properties and hot pressing recovery properties.

[0010] Preferably, the chemical formula of the photosensitive functional monomer is:

[0011]

[0012] The preparation method of the above-mentioned photosensitive functional monomer is carried out according to the following steps:

[0013] 1. Dissolve 1,4-phenylenediboronic acid and 1,2,4-butanetriol in a solvent, add deionized water and mix well, then add anhydrous magnesium sulfate, and react under stirring for 20 to 26 hours to obtain an intermediate product;

[0014] 2. Dissolve the intermediate product and the catalyst in a solvent, add 2-isocyanatoethyl acrylate, and stir the reaction at 70-75°C in an inert gas atmosphere. After infrared monitoring shows that the isocyanate group has reacted, terminate the reaction to obtain a photosensitive functional monomer.

[0015] Preferably, the solvent in step 1 is tetrahydrofuran or dichloromethane.

[0016] Preferably, the molar ratio of 1,4-phenylenediboric acid, 1,2,4-butanetriol and anhydrous magnesium sulfate in step 1 is 1:(1.9-2.1):(2.9-3.1).

[0017] Preferably, the amount of deionized water added in step 1 is 0.1 ml to promote the progress of the reaction.

[0018] Preferably, the solvent in step 2 is tetrahydrofuran or dichloromethane.

[0019] Preferably, the catalyst in step 2 is dibutyltin dilaurate.

[0020] Preferably, the molar ratio of the intermediate product to 2-isocyanatoethyl acrylate in step 2 is 1:(2-2.1).

[0021] The method for preparing a light-cured 3D printed polyurethane elastomer using the above-mentioned photosensitive functional monomer is carried out according to the following steps:

[0022] 1. Evenly mix 1% to 20% of photosensitive functional monomer, 60% to 99% of photosensitive resin monomer and 0% to 20% of active diluent according to mass percentage, then add photoinitiator and mix evenly to obtain slurry;

[0023] 2. Add the slurry into a 3D printer for 3D printing to obtain a polyurethane elastomer.

[0024] Preferably, the photosensitive resin monomer in step 1 is monofunctional polyurethane acrylate.

[0025] Preferably, the photoinitiator described in step 1 is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone or 1-hydroxycyclohexyl phenyl ketone; the amount of the photoinitiator used is 0.5% to 5% of the total mass of the photosensitive functional monomer, the photosensitive resin monomer and the reactive diluent.

[0026] Preferably, the active diluent in step 1 is hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylic acid, isobornyl acrylate, isobornyl methacrylate, 4-acryloylmorpholine, dicyclopentadienyl acrylate or benzyl acrylate.

[0027] Preferably, the 3D printing described in step 2 is: using ultraviolet light curing with a wavelength range of 265nm to 420nm. In the light-curing 3D printing process, the number of overexposure layers is set to 1 to 6 layers, the layer thickness is set to 10 to 150μm, the curing time of each layer is 500ms to 2000ms, and the light intensity is 10mw / cm 2 ~55mw / cm 2 The thickness of the remaining layers is set to 10-150 μm, the curing time of each layer is 500 ms-2000 ms, and the light intensity is 10 mw / cm 2 ~55mw / cm 2, a polyurethane elastomer is obtained, which has excellent self-repairing function and hot pressing recovery function.

[0028] Preferably, the ultraviolet light is ultraviolet light with a wavelength of 405 nm.

[0029] The present invention synthesizes a photosensitive functional monomer containing a dynamic borate ester bond through molecular design, and can prepare a photocurable 3D printable polyurethane elastomer with self-repairing and recyclable functions through copolymerization with monofunctional polyurethane acrylate and reactive diluent free radicals.

[0030] The photosensitive functional monomer containing a dynamic borate ester bond of the present invention has universal applicability, and any monofunctional photosensitive compound monomer or diluent can be used to prepare a photocurable 3D printing material with self-repairing and recyclable functions.

[0031] The self-healing property of the polyurethane elastomer prepared by the present invention is achieved through strong dynamic covalent bonds (boric acid ester bonds) and weak non-dynamic covalent bonds (hydrogen bonds). As non-covalent bonds, hydrogen bonds have a bond energy far less than boric acid ester bonds. However, the introduction of a large number of hydrogen bonds in the polyurethane molecular chain can not only improve the strength of the polyurethane elastomer, but also give the polyurethane elastomer a self-healing function at room temperature, and achieve 100% healing when heated at 80°C. Compared with other strong dynamic covalent bonds, such as DA bonds (the healing temperature is generally above 110°C), its healing temperature is mild and the healing efficiency is high.

[0032] The polyurethane elastomer prepared by the present invention can achieve a self-repairing function without adding a catalyst, thereby reducing the use of additional toxic catalysts.

[0033] The polyurethane elastomer prepared by the present invention has excellent mechanical properties, and its tensile strength reaches 3-8.6MPa, and the recycling method is simple, which reduces resource waste and environmental pollution. At the same time, the visible light transmittance of the polyurethane elastomer reaches 85%. Good light transmittance is not only conducive to the deep curing of the resin, but also compared with the colored polyurethane elastomer, the polyurethane elastomer with better transparency has a wider application range. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the infrared reflection spectrum of the intermediate BDB prepared in Example 1.

[0035] Figure 2 This is the hydrogen nuclear magnetic resonance spectrum of the intermediate BDB prepared in Example 1.

[0036] Figure 3 This is the infrared reflection spectrum of the photosensitive functional monomer ABDBA containing a borate ester bond prepared in Example 1.

[0037] Figure 4This is the hydrogen nuclear magnetic resonance spectrum of the photosensitive functional monomer ABDBA containing a borate ester bond prepared in Example 1.

[0038] Figure 5 It is a tensile test curve of polyurethane elastomer with different content of photosensitive functional monomer ABDBA in Application Examples 1 to 5.

[0039] Figure 6 This is a tensile test curve of the polyurethane elastomer prepared in Application Example 1 before and after self-repair.

[0040] Figure 7 This is the macroscopic healing tensile performance diagram of the polyurethane elastomer prepared in Application Example 1.

[0041] Figure 8 This is a graph showing the macroscopic healing performance of the polyurethane elastomer prepared in Application Example 1.

[0042] Fig. 9 This is a photo of hot pressing and recycling of the polyurethane elastomer prepared in Application Example 1.

[0043] Fig.10 This is a transmittance curve of the polyurethane elastomer prepared in Application Example 1.

[0044] Fig.11 This is a physical picture of the preparation of a sheet of polyurethane elastomer in Application Example 1. DETAILED DESCRIPTION

[0045] In order to describe the technical solution of the present invention more clearly and completely, the present invention is further described in detail through specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention. Various changes can be made within the scope of the rights of the present invention.

[0046] Embodiment 1: The preparation method of the photosensitive functional monomer of this embodiment is carried out according to the following steps:

[0047] 1. Add 3.0 g (18 mmol) of 1,4-phenylenediboronic acid to 80 mL of tetrahydrofuran, ultrasonically stir until 1,4-phenylenediboronic acid is completely dissolved, then add 3.816 g (36 mmol) of 1,2,4-butanetriol and 0.1 mL of deionized water, stir for 5 min, then add 6.48 g (54 mmol) of anhydrous MgSO4, stir and react at room temperature for 24 h, filter after the reaction, evaporate and concentrate the filtrate to obtain a white solid, then add the white solid to 60°C n-heptane and stir for 2 h to dissolve it, filter, evaporate and concentrate the filtrate to obtain a white product again, and finally dry the white product in a vacuum oven at 50°C for 24 h to obtain an intermediate product, recorded as BDB;

[0048] 2. Take 2.5g (8.2mmol) of BDB prepared in step 1 and dissolve it in 40mL of tetrahydrofuran, dissolve BDB by ultrasound, add 0.005g of dibutyltin dilaurate as a catalyst to obtain a mixed solution; then raise the temperature of the mixed solution to 70°C, slowly add 2.3124g (16.4mmol) of 2-isocyanate ethyl acrylate to the mixed solution, monitor the reaction progress by infrared, terminate the reaction when there is no isocyanate group by infrared reflection monitoring, remove the solvent tetrahydrofuran by rotary evaporation, and obtain a photosensitive functional monomer, denoted as ABDBA. The preparation of ABDBA is carried out under N2 atmosphere. ABDBA is a photosensitive functional monomer containing a borate ester bond.

[0049] The synthetic route of the intermediate product BDB in step 1 of this embodiment 1 is:

[0050]

[0051] The infrared reflection spectrum of the intermediate product BDB is shown in Figure 1 As shown, from Figure 1 It can be seen that at 1300cm -1 The asymmetric stretching vibration peak of the -BO group appears at 1170 cm -1 The bending vibration peak of the -B-OH group disappeared, indicating that the intermediate product BDB was successfully synthesized.

[0052] The H NMR spectrum of the intermediate product BDB is as follows: Figure 2 As shown, Figure 2 The attribution of each peak is given in Figure 2 As can be seen in 1 HNMR (400 MHz, DMSO-d6) δ7.70 (s, 2H), 4.96–4.63 (m, 1H), 4.47–3.91 (m, 3H), 3.65–3.47 (m, 2H), 2.10–1.70 (m, 2H), further indicating that the intermediate product BDB was successfully synthesized.

[0053] The synthetic route of ABDBA in step 2 of this embodiment 1 is as follows:

[0054]

[0055] The infrared reflection spectrum of the photosensitive functional monomer ABDBA is shown in Figure 3 As shown, from Figure 3 It can be seen that at 2265cm -1 The characteristic peak of -N=C=O at 1722cm-1 completely disappears, indicating that all -N=C=O groups react with -OH. -1 The C=C vibration peak appears at 1600~1650cm-1 At 1300cm -1 The asymmetric stretching vibration peak of the -BO- group appeared at , indicating that the photosensitive functional monomer ABDBA containing a borate ester bond was successfully synthesized.

[0056] The H NMR spectrum of the photosensitive functional monomer ABDBA is shown in Figure 4 As shown, Figure 4 The attribution of each peak is given in Figure 4 As can be seen in 1 H NMR (400 MHz,) δ7.69 (d, J = 14.2 Hz, 2H), 6.36 (d, J = 17.4 Hz, 1H), 6.05 (dd, J = 17.2, 10.7 Hz, 1H), 5.79 (dd, J = 10.4, 3.9 Hz, 1H), 5.39 (dt, J = 71.8, 6.1 Hz, 1H), 4.33–3.97 (m, 7H), 3.47–3.33 (m, 2H), 2.01–1.82 (m, 2H), indicating that the dynamic cross-linker based on boronate bond was successfully synthesized.

[0057] Application Example 1: A light-cured 3D printing polyurethane elastomer is prepared using the photosensitive functional monomer prepared in Example 1. The specific method is carried out according to the following steps:

[0058] 1. 12% of the photosensitive functional monomer ABDBA prepared in Example 1, 68% of the monofunctional polyurethane acrylate and 20% of hydroxyethyl acrylate were mixed uniformly according to the mass percentage to obtain a mixed solution; then 1% of the mass of the mixed solution was added with the photoinitiator I-819, and the mixture was mixed uniformly again to obtain a slurry;

[0059] 2. Add the slurry into the DLP printer for photocuring 3D printing of dumbbell-shaped samples and sheet samples. The laser wavelength of the photocuring is 405nm, the number of overexposure layers is 3, the thickness of each layer is 80μm, and the light intensity of the first layer is 15mw / cm 2 , the illumination time is 1000ms; the thickness of the remaining layers is 80μm, and the light intensity is 15mw / cm 2 , the illumination time is 900ms, and after printing is completed, the light-cured 3D printed dumbbell-shaped polyurethane elastomer samples and sheet samples are obtained.

[0060] Application Example 2: This application example differs from Application Example 1 in that in step 1, 9% of the photosensitive functional monomer ABDBA prepared in Example 1, 71% of the monofunctional polyurethane acrylate and 20% of hydroxyethyl acrylate are mixed uniformly by mass percentage to obtain a mixed solution; then, photoinitiator I-819 is added at 1% of the mass of the mixed solution, and mixed uniformly again to obtain a slurry; the other steps and parameters are the same as those in Application Example 1.

[0061] Application Example 3: This application example differs from Application Example 1 in that in step 1, 6% of the photosensitive functional monomer ABDBA prepared in Example 1, 74% of the monofunctional polyurethane acrylate and 20% of hydroxyethyl acrylate are mixed uniformly by mass percentage to obtain a mixed solution; then, photoinitiator I-819 is added at 1% of the mass of the mixed solution, and mixed uniformly again to obtain a slurry; the other steps and parameters are the same as those in Application Example 1.

[0062] Application Example 4: This application example differs from Application Example 1 in that in step 1, 3% of the photosensitive functional monomer ABDBA prepared in Example 1, 77% of the monofunctional polyurethane acrylate and 20% of hydroxyethyl acrylate are mixed uniformly by mass percentage to obtain a mixed solution; then, photoinitiator I-819 is added at 1% of the mass of the mixed solution, and mixed uniformly again to obtain a slurry; other steps and parameters are the same as those in Application 1.

[0063] Application Example 5: This application example differs from Application Example 1 in that in step 1, 80% of monofunctional polyurethane acrylate and 20% of hydroxyethyl acrylate are mixed uniformly by mass percentage to obtain a mixed solution; then, photoinitiator I-819 is added at 1% of the mass of the mixed solution, and mixed uniformly again to obtain a slurry; other steps and parameters are the same as those in Application 1.

[0064] The tensile test curves of the dumbbell-shaped polyurethane elastomer samples printed in Application Examples 1 to 5 are shown in Figure 5 The tensile strength and elongation at break of each sample are shown in Table 1.

[0065] Table 1 Tensile strength and elongation at break of dumbbell-shaped polyurethane elastomer samples printed in application examples 1 to 5

[0066] sample ABDBA content Tensile strength(MPa) Elongation at break (%) Application Example 1 12％ 8.64 285 Application Example 2 9％ 7.43 278 Application Example 3 6％ 5.68 463 Application Example 4 3％ 4.68 654 Application Example 5 0 3.25 1261

[0067] from Figure 5 As can be seen from Table 1, with the increase of the content of the photosensitive functional monomer ABDBA containing a borate bond, the tensile strength of the polyurethane elastomer sample increased from 3.25 MPa to 8.64 MPa, while the elongation at break gradually decreased from 1261% to 285%.

[0068] The dumbbell-shaped polyurethane elastomer sample printed in Application Example 1 was cut, and then the cross-section was tightly fitted and placed in an oven at 80°C for 12 hours to allow the cut dumbbell-shaped sample to heal. The strength of the healed dumbbell-shaped sample was tested and compared with the strength of the dumbbell-shaped polyurethane elastomer sample before it was damaged. The comparison chart is as follows: Figure 6 As shown, from Figure 6It can be seen that the tensile properties of the polyurethane elastomer and the original elastomer after healing at 80°C for 12 hours do not change much. This is because after the cut section is re-contacted, under heating conditions, the borate bonds can be exchanged, the hydrogen bonds are broken and reorganized, and the topological rearrangement of the network is re-realized, and the healing efficiency reaches 100%. This proves that the polyurethane elastomer has good self-healing properties.

[0069] The dumbbell-shaped polyurethane elastomer sample printed in Application Example 1 was cut into two sections, and then the sections were tightly butted at room temperature of 25°C for 1 hour. The macroscopic healing performance was as follows: Figure 7 and Figure 8 As shown, from Figure 7 It can be seen that no obvious cut surface can be seen after healing, and the healed sample still does not break after experiencing large deformation; Figure 8 It can be seen that the healed sample can withstand a weight of 600g without breaking, indicating that the sample has good room temperature healing ability.

[0070] The dumbbell-shaped polyurethane elastomer sample printed in Application Example 1 was cut into pieces with scissors, placed in a mold, and hot-pressed in a hot press at a temperature of 120°C for 3 hours at a pressure of 20 MPa. After cooling to room temperature, the polyurethane elastomer fragments were taken out and restored to a sheet-like whole. The photos before and after hot pressing are shown in the figure. Fig. 9 As shown, it is shown that polyurethane elastomer can be recycled by hot pressing.

[0071] The transmittance of the dumbbell-shaped polyurethane elastomer sample printed in Application Example 1 was tested, and the transmittance curve obtained is as follows: Fig.10 As shown, from Fig.10 It can be seen that the visible light transmittance of the polyurethane elastomer reaches 85%. Good transmittance is not only conducive to the deep curing of the resin, but also compared with colored polyurethane elastomers, polyurethane elastomers with better transparency have a wider range of applications.

[0072] The polyurethane elastomer sheet sample printed in Application Example 1 is placed on the color plate to test the transmittance of the polyurethane elastomer sheet sample. Fig.11 As shown, from Fig.11 It can be seen that the picture of the 1 mm thick polyurethane film superimposed on the colored paper card has almost no loss of clarity, which intuitively demonstrates the good transparency of the prepared polyurethane elastomer.

Claims

1. A photosensitive functional monomer, characterized in that The chemical formula of the photosensitive functional monomer is: Where m is 1, 2, 3 or 4; R is 2. A photosensitive functional monomer according to claim 1, characterized in that The chemical formula of the photosensitive functional monomer is:

3. A method for preparing a photosensitive functional monomer according to claim 1, characterized in that The method proceeds as follows:

1. Dissolve 1,4-phenylenediboronic acid and 1,2,4-butanetriol in a solvent, add deionized water and mix well, then add anhydrous magnesium sulfate, and react under stirring for 20 to 26 hours to obtain an intermediate product; 2. Dissolve the intermediate product and the catalyst in a solvent, add 2-isocyanatoethyl acrylate, and stir the reaction at 70-75°C in an inert gas atmosphere. After infrared monitoring shows that the isocyanate group has reacted, terminate the reaction to obtain a photosensitive functional monomer.

4. The method for preparing a photosensitive functional monomer according to claim 3, characterized in that: The solvent in step 1 is tetrahydrofuran or dichloromethane.

5. The method for preparing a photosensitive functional monomer according to claim 3 or 4, characterized in that: The molar ratio of 1,4-phenylenediboric acid, 1,2,4-butanetriol and anhydrous magnesium sulfate described in step 1 is 1:(1.9-2.1):(2.9-3.1).

6. The method for preparing a photosensitive functional monomer according to claim 3 or 4, characterized in that: The molar ratio of the intermediate product to 2-isocyanatoethyl acrylate in step 2 is 1:(2-2.1).

7. A method for preparing a light-cured 3D printed polyurethane elastomer using a photosensitive functional monomer according to claim 1, characterized in that: The method proceeds as follows:

1. Evenly mix 1% to 20% of photosensitive functional monomer, 60% to 99% of photosensitive resin monomer and 0% to 20% of active diluent according to mass percentage, then add photoinitiator and mix evenly to obtain slurry; 2. Add the slurry into a 3D printer for 3D printing to obtain a polyurethane elastomer.

8. The method for preparing a light-cured 3D printed polyurethane elastomer using a photosensitive functional monomer according to claim 7, characterized in that: The photosensitive resin monomer described in step 1 is monofunctional polyurethane acrylate.

9. The method for preparing a light-cured 3D printed polyurethane elastomer using a photosensitive functional monomer according to claim 7 or 8, characterized in that: The photoinitiator described in step 1 is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone or 1-hydroxycyclohexyl phenyl ketone; the amount of the photoinitiator is 0.5% to 5% of the total mass of the photosensitive functional monomer, the photosensitive resin monomer and the active diluent.

10. The method for preparing a light-cured 3D printed polyurethane elastomer using a photosensitive functional monomer according to claim 7 or 8, characterized in that: The active diluent described in step 1 is hydroxyethyl acrylate, hydroxyethyl methacrylate, acrylic acid, isobornyl acrylate, isobornyl methacrylate, 4-acryloylmorpholine, dicyclopentadienyl acrylate or benzyl acrylate.

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