3D printing material suitable for photocuring and preparation method thereof

Abstract

The invention provides a 3D printing material suitable for photocuring and a preparation method thereof. The 3D printing material comprises an acrylic-terminated hydrogenated nitrile rubber prepolymer, a reactive diluent, a photoinitiator and a light absorbing agent, the structural general formula of the acrylic-terminated hydrogenated nitrile rubber prepolymer is as shown in formula 1, and in the formula 1, R1 and R4 are respectively and independently at least one of C2-C10 alkylene groups; r < 2 > and R < 5 > are respectively and independently at least one of alkylene groups of C < 2 > to C < 10 >; r3 and R6 are respectively and independently at least one of the following; x is 10-40, y is 10-40, and z is 10-40. The 3D printing material provided by the invention can be rapidly cured to realize 3D printing, the oil resistance of the 3D printing material is equivalent to that of traditional HNBR, repeated printing and parallel printing can be realized, and a 3D printing product has a shape memory effect.

Description

Technical Field

[0001] This invention relates to the field of 3D printing materials technology, and in particular to a photopolymerizable 3D printing material and its preparation method. Background Technology

[0002] Photopolymer 3D printing technology, based on digital model files, is a rapid prototyping technology that uses layer-by-layer printing to build up materials into the shape designed in the model. It boasts advantages such as simple printing operation, high precision, and the ability to create structures impossible to achieve with conventional printing techniques. While photosensitive resin 3D printing imparts excellent stability to the devices, its recycling is extremely difficult, leading to significant resource waste and environmental pollution. Furthermore, photopolymer 3D printing is slow and time-consuming.

[0003] Polyurethane possesses properties such as adjustable modulus, high recovery rate, and excellent wear and impact resistance. Currently reported 3D printing of shape memory polyurethane materials primarily employs fused deposition modeling (FDM). Because most of these materials use polyethylene glycol, polytetrafluoroethylene (PTFE), and polybutadiene with molecular weights of 2000-4000 as the soft segments of the polyurethane, the resulting elastomer has a highly cross-linked network structure, resulting in either a soft, inelastic texture or a hard, easily broken structure, significantly deviating from the properties of traditional rubber.

[0004] Therefore, existing 3D printing resins need improvement. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in the prior art. Therefore, one object of this invention is to provide a photopolymerizable 3D printing material and a method for preparing the same.

[0006] In a first aspect, the present invention provides a photopolymerizable 3D printing material comprising: Acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer, reactive diluent, photoinitiator and light absorber.

[0007] The general structural formula of the acrylic-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer is shown in Formula 1: Where R1 and R4 are independent C2-C10 alkylene groups , At least one of them.

[0008] R2 and R5 are independently... C2-C10 alkylene groups At least one of them.

[0009] R3 and R6 are independently... , , At least one of them.

[0010] x is 10⁻⁴⁰, y is 10⁻⁴⁰, z is 10⁻⁴⁰.

[0011] The 3D printing material provided by this invention comprises an acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer, a reactive diluent, a photoinitiator, and a light absorber. Hydrogenated nitrile butadiene rubber (HNBR) is based on NBR, where hydrogenation saturates the double bonds on the polybutadiene segments of its molecular chain, resulting in excellent oil resistance and aging resistance. This invention introduces acrylic photosensitive groups (acrylate groups) that react rapidly under ultraviolet light into traditional HNBR, enabling HNBR to cure rapidly under ultraviolet light, thus giving it 3D printing characteristics, and producing prints with oil resistance comparable to traditional HNBR. Meanwhile, the introduction of reversible dynamic bonds (hindered urea bonds) in the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer enables repeated 3D printing of the cured HNBR. This involves crushing the printed HNBR elastomer and, under specific temperature conditions, dissociating the dynamic bonds to expose -NCO. Adding a certain amount of hydroxyl / amino-containing acrylic acid allows it to react with the exposed -NCO, re-imparting the photocurable properties of the HNBR and enabling repeated 3D printing. Furthermore, the oil resistance of the reprinted parts is improved. In addition, the introduction of dynamic bonds gives HNBR self-welding properties. Multiple HNBR printed parts can be joined together, and printing material can be dripped at the joints. Under UV light and heating, multiple parts are welded together. This allows for parallel printing of intricate products compared to traditional methods, significantly reducing 3D printing time. Simultaneously, the printed parts prepared with this 3D printing material exhibit excellent mechanical properties, solving the problems of existing polyurethane materials being soft and inelastic, or hard and brittle. The reactive diluent can adjust the viscosity of the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer, so that the viscosity of the final printing material is less than 5 Pa·s, which meets the requirements of 3D printing.

[0012] In some embodiments of the present invention, the C2-C10 alkylene group includes at least one of ethylene, propylene, butylene, pentylene, hexylene, alkyl-substituted butylene with 1-2 carbon atoms, alkylpentylene with 1-2 carbon atoms, and alkylhexylene with 1-2 carbon atoms.

[0013] For example, -CH2-CH2-CH2-, -CH2-CH2-CH2-CH2-CH2-CH2-, -CH2-CH(CH3)-CH2-CH2-, etc.

[0014] In some embodiments of the present invention, the molecular weight of the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer is 2kDa-60kDa. For example, molecular weights of 2kDa, 5kDa, 10kDa, 20kDa, 30kDa, 60kDa, etc., or any range between two of the above values. Controlling the molecular weight of the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer within the above range allows for rapid crosslinking and curing under ultraviolet light.

[0015] In some embodiments of the present invention, the mass ratio of the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer, the reactive diluent, the photoinitiator and the light absorber is (10-90):(10-90):(0.5-10):(0.02-1), preferably 100:(35-60):(1-5):(0.2-0.5).

[0016] In some embodiments of the present invention, the mass ratio of the acrylic-terminated hydrogenated nitrile rubber prepolymer to the reactive diluent is (10-90):(10-90), preferably (20-80):(20-80), and more preferably (30-60):(30-60).

[0017] In some embodiments of the present invention, the mass fraction of the acrylate-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer is 20-80%, preferably 30-60%, based on the total mass of the photocurable 3D printing material.

[0018] In some embodiments of the present invention, the mass fraction of the reactive diluent is 20-80%, preferably 30-60%, based on the total mass of the photocurable 3D printing material.

[0019] Preferably, based on the total mass of the photocurable 3D printing material, the mass fraction of the acrylate-terminated hydrogenated nitrile butadiene rubber prepolymer is 30-60%, and the mass fraction of the reactive diluent is 30-60%.

[0020] In some embodiments of the present invention, the active diluent is at least one of hydroxyethyl methacrylate, trimethylolpropane triacrylate, and isobornyl acrylate.

[0021] In some embodiments of the present invention, the photoinitiator is selected from at least one of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide and ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

[0022] In some embodiments of the present invention, the light absorber is selected from 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene.

[0023] In some embodiments of the present invention, the method for preparing the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer includes: Hydroxyl-terminated hydrogenated butyronitrile is dissolved in an organic solvent to obtain solution A.

[0024] Diisocyanate and catalyst were added to solution A to carry out a first reaction, yielding NCO-HHTBN-NCO.

[0025] Then, a polyol is added to the system to carry out a chain extension reaction.

[0026] Finally, an acrylic monomer is added to the system to carry out a second reaction, yielding an acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer. The acrylic monomer contains active groups, which are hydroxyl and / or amino groups.

[0027] In some embodiments of the present invention, the mass fraction of hydroxyl-terminated hydrogenated butyronitrile in solution A is 2-50%.

[0028] In some embodiments of the present invention, the organic solvent is selected from at least one of tetrahydrofuran, chlorobenzene, xylene, dichloromethane, and N,N-dimethylformamide. Since tetrahydrofuran has a low boiling point and is highly volatile, using tetrahydrofuran as a solvent makes subsequent solvent removal easier.

[0029] In some embodiments of the present invention, the catalyst is selected from dibutyltin dilaurate, and the amount of catalyst added is 0.02-5.0% of the mass of the hydroxyl-terminated hydrogenated butyronitrile.

[0030] In some embodiments of the present invention, the diisocyanate is selected from one or more of diphenylmethane diisocyanate, hexamethylene diisocyanate, isoflurone diisocyanate, and toluene diisocyanate.

[0031] In some embodiments of the present invention, the polyol is selected from one or more of 1,4-butanediol, trimethylolpropane, neopentyl glycol, and propylene glycol.

[0032] In some embodiments of the present invention, the acrylic monomer is selected from one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, and 2-(tert-butylamino)methacrylate.

[0033] In some embodiments of the present invention, the molar ratio of -NCO in the diisocyanate to -OH in the hydroxyl-terminated hydrogenated butyronitrile is (0.8-20):1.

[0034] In some embodiments of the present invention, the molar ratio of -OH in the polyol to -NCO in the NCO-HHTBN-NCO is (0.05-20):1.

[0035] In some embodiments of the present invention, the molar ratio of the active group in the acrylic monomer to the -NCO in NCO-HHTBN-NCO is (0.05-20):1.

[0036] In some embodiments of the present invention, the first reaction is carried out under an inert atmosphere, the temperature of the first reaction is 20-90°C, and the time of the first reaction is 2h-9h.

[0037] In some embodiments of the present invention, the chain extension reaction is carried out under an inert atmosphere, the temperature of the chain extension reaction is 20-80°C, and the time of the chain extension reaction is 1-6 hours.

[0038] In some embodiments of the present invention, the second reaction is carried out under an inert atmosphere, the temperature of the second reaction is 20-80°C, and the time of the first reaction is 1-6 hours.

[0039] In a second aspect, the present invention provides a method for preparing the above-mentioned photopolymerizable 3D printing material, comprising: Under dark and light-protected conditions, the acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer, reactive diluent, photoinitiator, and light absorber are mixed evenly.

[0040] The present invention has at least the following beneficial effects: The photopolymerizable HNBR photosensitive resin for 3D printing provided by this invention is made from a specific ratio of acrylic-terminated HNBR prepolymer, reactive diluent, light absorber, and photoinitiator. It can cure rapidly to achieve 3D printing, and its oil resistance is comparable to traditional HNBR. Furthermore, due to the introduction of dynamic bonds with reversible properties into the system, repeated and parallel printing can be achieved, significantly shortening the 3D printing time. The 3D printed products also exhibit shape memory effect, greatly expanding the possibilities for HNBR molding methods. The printed parts prepared from this 3D printing material possess excellent mechanical properties, solving the problems of existing polyurethane materials being soft and inelastic, and hard and easily broken. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a structural diagram of the acrylic-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer prepared in Example 1 of the present invention.

[0043] Figure 2This is the infrared spectrum of the acrylic-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer prepared in Example 1 of this invention.

[0044] Figure 3 This is the NMR spectrum of the acrylic-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer of Example 1 of the present invention.

[0045] Figure 4 This is a physical image of a finely structured printed part produced by the 3D printing material of Embodiment 1 of the present invention, along with the results of an elasticity test.

[0046] Figure 5 This is a physical demonstration image of a self-welding object printed using 3D printing material according to Embodiment 1 of the present invention.

[0047] Figure 6 This is a physical demonstration image of the repeated printing of the 3D printing material according to Embodiment 1 of the present invention.

[0048] Figure 7 This is a 4D printing demonstration diagram of the 3D printing material of Embodiment 1 of the present invention. Detailed Implementation

[0049] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way.

[0050] Example 1 (1) This embodiment provides an acrylic-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer, and the specific preparation process is as follows: Hydroxyl-terminated HTBN (HHTBN) with a number-average molecular weight of 10 kDa, after vacuum drying, was dissolved in anhydrous THF to prepare a 10% (w / w) solution. A measured amount of isoflurane diisocyanate (the molar ratio of -OH in HHTBN to -NCO in IPDI was 1:7) was added, along with dibutyltin dilaurate (0.1% of the HHTBN mass fraction). The mixture was reacted at 70 °C for 8 h under a nitrogen atmosphere to prepare NCO-HHTBN-NCO. After the reaction was completed, the temperature was lowered to 60℃, and a measured amount of trimethylolpropane (the molar ratio of -NCO in NCO-HHTBN-NCO to -OH in trimethylolpropane was 5:1) was added. The reaction was carried out under a nitrogen atmosphere for 4 hours. After the reaction was completed, a measured amount of ethyl 2-(tert-butylamino)methacrylate (the molar ratio of -NCO in NCO-HHTBN-NCO to -NH in ethyl 2-(tert-butylamino)methacrylate was added. The reaction was carried out under a nitrogen atmosphere at 50℃ for 2 hours to prepare an acrylic-terminated hydrogenated HNBR prepolymer.

[0051] The structural diagram of the acrylic-terminated hydrogenated butadiene-acrylonitrile rubber prepolymer prepared in Example 1 is shown below. Figure 1 As shown.

[0052] like Figure 2 and Figure 3 As shown, characterization by infrared and nuclear magnetic resonance at 813 cm⁻¹ -1 1648cm -1 The presence of characteristic peaks for the photosensitive group -C(CH3)=CH- at δ=5.5, 6.1, and 6.4 ppm indicates the successful preparation of acrylic acid-terminated HNBR prepolymers. Molecular weights are shown in Table 1.

[0053] Table 1

[0054] (2) This embodiment provides a photopolymerizable 3D printing material, and the specific preparation process is as follows: The acrylic-terminated HNBR prepolymer prepared in step (1) was rotary evaporated at 38°C to remove anhydrous THF solvent. The evaporated product was placed in a fume hood for 12 hours under light-protected conditions and then divided into 4 groups (100 parts by weight of HNBR prepolymer in each group). 20 parts by weight of isobornyl acrylate (group 1), 30 parts by weight of isobornyl acrylate (group 2), 40 parts by weight of isobornyl acrylate (group 4) were added to each group respectively. 1 part by weight of ethyl 2,4,6-trimethylbenzoylphenylphosphonate and 0.2 parts by weight of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene were added to each group respectively. After mixing evenly, the mixture was stirred at room temperature for 24 hours under light-protected conditions to remove air bubbles in the photosensitive resin. This mixture was then used as a photocurable 3D printing material.

[0055] 1) The viscosity of the four groups of photocurable 3D printing materials was measured, and the specific results are shown in Table 2.

[0056] Table 2

[0057] As shown in Table 2, the viscosity of the photocurable 3D printing materials in groups 3 and 4 of the present invention is less than 5 Pa·s, which meets the viscosity requirements for DLP 3D printing.

[0058] 2) The photocurable 3D printing materials of Group 3 and Group 4 were dropped into a 10cm×10cm PTFE mold and irradiated with ultraviolet light with a wavelength of 405nm for 5min to prepare a film with a thickness of 2mm. The mechanical properties were tested and the results are shown in Table 3.

[0059] Table 3

[0060] As shown in Table 3, the films prepared by the photocurable 3D printing material of the present invention have high tensile strength and elongation at break, indicating that the printed parts prepared by the photocurable 3D printing material of the present invention have excellent mechanical properties.

[0061] 3) Use the photopolymer 3D printing material from group 4 for 3D printing. Pour the photopolymer 3D printing material into the ink tank of the PhrozenSonic Mini 8KS 3D printer, import the printing model, and print. The parameter settings are shown in Table 4. After the 3D printed part is formed, immerse it in anhydrous ethanol to clean the surface of residual prepolymer, and then irradiate it with ultraviolet light at a wavelength of 405nm for 10 minutes for post-curing.

[0062] Table 4

[0063] The printing accuracy of different printing parameters was characterized by SEM scanning of the texture of the printed object. The highest printing accuracy was achieved when the printing parameters were 5 printing layers, 40s exposure time for the bottom layer, and 14s exposure time. These parameters were then used for subsequent 3D printing.

[0064] Comparative Example 1 The 3D printing parameters used in Comparative Example 1 are the same as the highest printing accuracy parameters used in 3) of Example 1, except that the photocurable 3D printing material in group 4 of Example 1 is replaced with a commercial 3D printing photosensitive resin. The printed material of Comparative Example 1 has the same accuracy as the printed material of Example 1.

[0065] 4) Oil resistance test The printed parts printed with the 3D printing material of group 4 in Example 1 were immersed in test oil and soaked at 150 °C for 24 h. The samples were then taken out, the test oil on the sample surface was wiped off, and the samples were weighed and the mass expansion rate was calculated. The swelling rate of the HNBR 3D printed parts in 903# oil was 52.9%, and the swelling rate in 15# oil was 26.5%.

[0066] Comparative Example 2 Comparative Example 2 uses hydrogenated nitrile butadiene rubber. The oil resistance of the printed parts printed with the 3D printing material of Group 4 in Example 1 is compared with that of the hydrogenated nitrile butadiene rubber. The oil resistance test method is the same as that of 4).

[0067] The results of the oil resistance test are shown in Table 5.

[0068] Table 5

[0069] 5) Printing of fine structures The items printed in 3) above are simple two-dimensional objects. To further demonstrate the printing performance of the printing material of this invention, the optimal 3D printing parameters and printing method in 3) were used. The photopolymerizable 3D printing material of group 5 in Example 1 was used to successfully print a "honeycomb" structure and a rose. Furthermore, after applying external force to the "honeycomb" structure and removing the force, the "honeycomb" structure instantly recovers. Figure 4 As shown, the HNBR 3D printed material exhibits good elasticity.

[0070] 6) Printed self-welding Taking the "Ancient Roman Colosseum" model as an example, using the optimal 3D printing parameters and method of Example 1, separate parts of the "Ancient Roman Colosseum" model were printed. After assembling them together, the photocurable 3D printing material of group 5 of Example 1 was dripped onto the joint. After irradiation with ultraviolet light at a wavelength of 405nm for 5 minutes, it was heated at 60℃ for 1 hour. The process is as follows. Figure 5 As shown, self-welding of HNBR 3D printing was achieved, enabling parallel 3D printing and reducing 3D printing time.

[0071] 7) Self-welding performance test The 3D printing material from group 4 of Example 1 was laid into a 1.5 mm thick film. After irradiation under ultraviolet light with a wavelength of 405 nm for 5 minutes, the sample was cut into a bone shape with a length of 35 mm and a width of 4 mm using a mold. Its mechanical properties were characterized using an AI-7000SU1 universal tensile testing machine from the High-Speed ​​Railway Company. The prepared bone-shaped sample was cut in the middle, and the 3D printing material from group 4 was applied to the cut surface and the gap. The cut sample was then reassembled, and the gap was irradiated with ultraviolet light with a wavelength of 405 nm for 5 minutes. After heating at 60°C for 1 hour, its mechanical properties were tested. The tensile strength of the sample after self-welding was 15.7 MPa, indicating that the mechanical properties of the sample before and after self-welding were similar.

[0072] 8) Recyclability of printed parts After the printed material prepared in step 3) was shredded, it was dissolved in chlorobenzene, and a measured amount of ethyl 2-(tert-butylamino)methacrylate was added. After reacting at 90°C for 4 hours under a nitrogen atmosphere, the chlorobenzene solvent in the system was removed by rotary evaporation at 60°C, resulting in a pale yellow oily liquid. This indicates that the dynamic bonds of the HNBR 3D printed material were dissociated, and the HNBR 3D printed material was recovered.

[0073] 9) Repeated printing of 3D printing materials Add 20 wt% of the fresh acrylic-terminated hydrogenated nitrile butadiene rubber prepolymer prepared in Example 1 to the oily liquid in step 8), stir for 6 h under light-protected conditions, and add the corresponding photoinitiator and light absorber according to the method in step (2) of Example 1 to obtain the photosensitive resin for repeated 3D printing. The viscosity test result is less than 5 Pa·s. Using the optimal 3D printing parameters and printing method in step 3), a window flower model was printed. Figure 6 As shown in the figure, repeatable 3D printing of HNBR was achieved.

[0074] 10) Oil resistance test of repeatedly printed parts made from 3D printing materials. Using the oil resistance test method in 4), the oil resistance of the repeated 3D printed material in 9) was tested. The test results are shown in Table 6. As can be seen from Table 6, the swelling rate in 903# oil was consistent after the second printing, while the swelling rate in 15# oil decreased, indicating that the oil resistance of the second printed material was improved.

[0075] Table 6

[0076] 11) 4D printing Using the optimal precision 3D printing parameters and method (3), a butterfly model was printed using the 3D printing material of group 4 in Example 1. The model was heated to 90°C, stress was applied to edit its shape, and then cooled to 20°C to fix the temporary shape. Figure 7 The butterfly wings shown flap, and when heated to 90°C again, the butterfly wings return to their original shape, thus achieving 4D printing.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photopolymerizable 3D printing material, characterized in that, Comprising: an acrylic group terminated hydrogenated nitrile rubber prepolymer, a reactive diluent, a photoinitiator and a light absorber; a structural general formula of the acrylic group terminated hydrogenated nitrile rubber prepolymer is shown as Formula 1: wherein R1and R4are each independently C2-C10alkylene, , at least one of R2and R5are each independently C2-C10alkylene, at least one of R3and R6are each independently , , at least one of x is 10-40, y is 10-40, and z is 10-40.

2. The 3D printing material according to claim 1, wherein The C2-C10 alkylene group includes at least one of ethylene, propylene, butylene, pentylene, hexylene, alkyl-substituted butylene with 1-2 carbon atoms, alkyl-pentylene with 1-2 carbon atoms, and alkyl-hexylene with 1-2 carbon atoms.

3. The 3D printing material of claim 1, wherein, The molecular weight of the acrylic group terminated hydrogenated nitrile rubber prepolymer is 2 kDa-60 kDa; And / or, the mass ratio of the acrylic group terminated hydrogenated nitrile rubber prepolymer, the reactive diluent, the photoinitiator and the light absorber is (10-90):(10-90):(0.5-10):(0.02-1), preferably 100:(35-60):(1-5):(0.2-0.5).

4. The 3D printing material according to any one of claims 1-3, wherein, The reactive diluent is at least one of hydroxyethyl methacrylate, trimethylolpropane triacrylate, and isobornyl acrylate; And / or, the photoinitiator is selected from at least one of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide and 2,4,6-trimethylbenzoyl phenyl phosphinic acid ethyl ester; And / or, the light absorber is selected from 2,5-bis (5-tert-butyl-2-benzoxazolyl) thiophene.

5. The 3D printing material according to any one of claims 1-3, wherein, The preparation method of the acrylic group terminated hydrogenated nitrile rubber prepolymer comprises: dissolving the hydroxyl-terminated hydrogenated nitrile in an organic solvent to obtain solution A; adding diisocyanate and a catalyst to the solution A to perform a first reaction to obtain NCO-HHTBN-NCO; then adding a polyol to the system to perform a chain extension reaction; finally, adding an acrylic monomer containing active groups, which are hydroxyl and / or amino, to the system to perform a second reaction to obtain the acrylic group terminated hydrogenated nitrile rubber prepolymer.

6. The 3D printing material according to claim 5, wherein, The mass fraction of the hydroxyl-terminated hydrogenated nitrile in the solution A is 2-50%; And / or, the organic solvent is selected from at least one of tetrahydrofuran, chlorobenzene, xylene, dichloromethane, and N,N-dimethylformamide; And / or, the catalyst is selected from dibutyltin dilaurate, and the addition amount of the catalyst is 0.02-5.0% of the mass of the hydroxyl-terminated hydrogenated nitrile.

7. The 3D printing material of claim 5, wherein, The diisocyanate is selected from one or more of diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and toluene diisocyanate; And / or, the polyol is selected from one or more of 1,4-butanediol, trimethylolpropane, neopentyl glycol, and propylene glycol; And / or, the acrylic monomer is selected from one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, and 2-(tert-butylamino)ethyl methacrylate.

8. The 3D printing material of claim 5, wherein, The molar ratio of -NCO in the diisocyanate to -OH in the hydroxyl-terminated hydrogenated nitrile is (0.8-20):

1. And / or, the molar ratio of -OH in the polyol to -NCO in the NCO-HHTBN-NCO is (0.05-20):1; And / or, the molar ratio of the active group in the acrylic monomer to -NCO in the NCO-HHTBN-NCO is (0.05-20):

1.

9. The 3D printing material of claim 5, wherein, The first reaction is carried out under an inert atmosphere, the temperature of the first reaction is 20-90℃, and the time of the first reaction is 2h-9h; And / or, the chain extension reaction is carried out under an inert atmosphere, the temperature of the chain extension reaction is 20-80℃, and the time of the chain extension reaction is 1h-6h; And / or, the second reaction is carried out under an inert atmosphere, the temperature of the second reaction is 20-80℃, and the time of the first reaction is 1h-6h.

10. A method of preparing the photopolymerizable 3D printing material according to any one of claims 1 to 9, characterized in that, Comprise: Mix the acrylic group terminated hydrogenated butyl nitrile rubber prepolymer, active diluent, photoinitiator and light absorber uniformly under dark and light shielding conditions.

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