A light-cured printing high-precision gel material and a preparation method thereof

Abstract

The application belongs to the field of light-curing printing, and particularly relates to a light-curing printing high-precision gel material and a preparation method thereof. The application provides a light-curing printing high-precision gel material and a preparation method thereof. The gel material is prepared by using monomer N-vinyl pyrrolidone (VP) as a solvent and monomer acrylamide (AM) as a solute. The hydrogel prepared by 3D printing has high mechanical properties and can realize high printing precision. The acrylamide has phase separation behavior in the N-vinyl pyrrolidone solution, which can regulate the spatial distribution of light, thereby realizing efficient utilization of light and regulation of the polymerization reaction of monomers, and thus realizing high-precision gel light-curing printing.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of light-cured printing, and particularly relates to a light-cured printing high-precision gel material and a preparation method thereof. BACKGROUND

[0002] At present, due to good biocompatibility of hydrogel, light-cured printing gel is widely applied in the fields of biomedical science and tissue engineering, etc. However, due to the intrinsic loose porous structure of the gel material, the printing precision and mechanical property of the gel material are not high. The existing technical solutions are difficult to realize sub-micron high-precision hydrogel 3D printing below 50 microns, for example, extrusion type 3D printing is the mainstream method for preparing hydrogel at present, and the printing precision is usually above 100 um. In recent years, the two-photon 3D printing technology has emerged, which can realize sub-micron printing, but the two-photon printing device is expensive, the printing speed is slow, the printing efficiency is low, and the printing size is small, which seriously restricts the application of the printing technology.

[0003] At present, although the light-cured printing technology has researched many gel materials with fast curing speed and wide material sources, the printing precision and mechanical property are further improved, but it is also difficult to achieve sub-micron high-precision gel printing below 50 um pores and super high mechanical property.

[0004] In view of this, the application is proposed. SUMMARY

[0005] In order to achieve the above purpose, the first technical solution of the application provides a light-cured printing high-precision gel material, which comprises acrylamide, N-vinyl pyrrolidone, a crosslinking agent, an initiator and a light absorber.

[0006] Further, the mass ratio of the acrylamide to the N-vinyl pyrrolidone is (1:9) to (3.5:6.5).

[0007] Further, the mass ratio of the acrylamide to the N-vinyl pyrrolidone is (1:9) to (3.5:6.5).

[0008] Preferably, the mass ratio of the acrylamide to the N-vinyl pyrrolidone is 3.5:6.5.

[0009] Preferably, the crosslinking agent is polyethylene glycol diacrylate, the initiator is lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt, and the light absorber is curcumin.

[0010] Preferably, the addition amount of the polyethylene glycol diacrylate, lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt and curcumin is 1:0.02:0.003:0.0012, based on the total mass of acrylamide and N-vinylpyrrolidone.

[0011] The second technical solution of the present application provides a preparation method of the light-cured printing high-precision gel material, comprising:

[0012] Mixing and stirring acrylamide and N-vinylpyrrolidone to obtain a clear solution;

[0013] Adding a crosslinking agent, an initiator and a light absorber into the clear solution and mixing uniformly to obtain the light-cured printing high-precision gel material.

[0014] The present application has the following beneficial effects: the present application uses N-vinylpyrrolidone as a solvent and acrylamide as a solute to mix and copolymerize a gel solution, compared with the prior art which uses water or ethanol solution as a solvent, the gel obtained by the present application has more excellent mechanical properties, provides strong support for high-precision three-dimensional structures, can realize high-precision printing, and controls the printing precision below 50um, especially when the addition mass ratio of acrylamide and N-vinylpyrrolidone is 3.5:6.5, the printing precision can be controlled to about 1um.

[0015] The acrylamide in the present application undergoes phase separation behavior in N-vinylpyrrolidone, which can regulate the spatial distribution of light, realize efficient utilization of light and control of monomer polymerization reaction, so that high-precision printing can be realized while light-cured printing is also realized.

[0016] The crosslinking agent of the present application is preferably ethylene glycol diacrylate, the initiator is preferably lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt, and the light absorber is preferably curcumin, ethylene glycol diacrylate is easily soluble in N-vinylpyrrolidone, so that the crosslinking agent plays a stronger role, the initiator can be decomposed into free radical lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt under 405nm ultraviolet light, and curcumin can well regulate the printing rate and printing resolution under 405nm ultraviolet light, so that the present application can significantly improve the printing precision when printing under 405nm ultraviolet light, compared with the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0017] The present application is a gel solution prepared by mixing acrylamide and N-vinylpyrrolidone as solute and solvent, and copolymerizing the gel solution. Figure 1 A model for testing printing precision;

[0018] Figure 2 Figure 2 SEM images of printed line precision for acrylamide and N-vinyl pyrrolidone ratio of 3.5:6.5;

[0019] Figure 3 Figure 3 High definition photographs of the configuration solutions of Examples 2-6 after being mixed thoroughly under ultrasonic and cooled to room temperature; Figure 4 Figure 4

[0020] Figure 5 Figure 5 Figure 6

[0021] Figure 7 Figure 6 Figure 8 DETAILED DESCRIPTION

[0022] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0024] Unless otherwise defined, scientific and technical terms used in this specification shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs, although it is intended to be interpreted as being synonymous to the commonly used terms and / or phrases used herein. If there is a discrepancy or conflict between the definitions provided in this specification and that in commonly used dictionaries due to usage, the definition provided in this specification prevails.

[0025] In the context of the present application, the terms "comprising" or "including" do not exclude other possible elements. The composition of the present application, including the various embodiments described herein, can comprise, consist of, or consist essentially of the elements presented herein, with the understanding that the application encompasses any and all necessary limitations of the process, reagent, article, composition, system, method, use and / or steps, whether or not expressly described in the above

[0026] The present application will now be described in greater detail. It should be noted that the various aspects, features, embodiments, examples of the present application described can be compatible and / or can be combined together.

[0027] The first embodiment of the present application discloses a light-cured printing high-precision gel material, which comprises acrylamide, N-vinyl pyrrolidone, a crosslinking agent, an initiator and a light absorber.

[0028] Currently, researchers in the field ignore the influence of solvents on the chemical or physical properties of gel raw materials. In the market, water or ethanol solution is generally selected as the solvent for dissolving the gel material for light-cured printing. However, both water and ethanol as solvents can affect the mechanical properties and precision of printing. Therefore, the inventors of the present application have conducted in-depth research on the solvent of the gel material, and found that the use of N-vinyl pyrrolidone, which is also a monomer, as a solvent, and the addition of acrylamide can greatly improve the mechanical properties. Moreover, acrylamide undergoes phase separation behavior in the N-vinyl pyrrolidone solution, which regulates the spatial distribution of light, realizes efficient utilization of light and monomer polymerization control, and can improve the printing precision.

[0029] It should be noted that the applicant found in the research process that the ratio of acrylamide and N-vinyl pyrrolidone has different effects on the improvement of mechanical properties, and the ratio is in the range of (1:9) to (3.5:6.5). The maximum printing precision of the gel material obtained in this range is less than 50 um, and the mechanical properties of the printed sample are the best.

[0030] In a preferred embodiment, the mass ratio of acrylamide to N-vinyl pyrrolidone is 3.5:6.5. Under this ratio, the maximum printing precision of the obtained gel material can reach about 1 nm, and the mechanical properties are also greatly improved, with a compressive strength of 1500 Mpa.

[0031] Preferably, the crosslinking agent is polyethylene glycol diacrylate, the initiator is lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt, and the light absorber is curcumin.

[0032] In a preferred embodiment, the total mass of acrylamide and N-vinyl pyrrolidone is 1, and the addition amount of polyethylene glycol diacrylate, lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt and curcumin is 1:0.02:0.003:0.0012.

[0033] In the present embodiment, ethylene glycol diacrylate is easily soluble in N-vinyl pyrrolidone, making the crosslinking agent play a stronger role. The initiator can be decomposed into free radical lithium phenyl (2,4,6-trimethylbenzoyl) phosphate salt under 405 nm ultraviolet light, and curcumin can well regulate the printing rate and printing resolution under 405 nm ultraviolet light, thereby significantly improving the printing precision under 405 nm ultraviolet light compared with the prior art.

[0034] The second embodiment of the present application provides a preparation method of the light-cured printing high-precision gel material of the first embodiment, comprising:

[0035] Mixing and stirring acrylamide and N-vinyl pyrrolidone to obtain a clear solution;

[0036] Adding a crosslinking agent, an initiator and a light absorber to the clear solution, and mixing uniformly to obtain the light-cured printing high-precision gel material.

[0037] The effects of the addition amounts of acrylamide and N-vinyl pyrrolidone on the performance of the gel material will be described in detail below through specific examples.

[0038] Example 1 Preparation of gel material

[0039] 1. The raw materials and addition amounts for preparing the gel material in this example are shown in Table 1

[0040]

[0041] 2. Preparation method of gel material

[0042] The raw materials described in Examples 1-6 and Comparative Examples 1-6 were prepared into gel materials by the following method

[0043] S1. Mixing the solute and the solvent and stirring thoroughly to obtain a clear solution;

[0044] S2. Adding 0.2 g of polyethylene glycol diacrylate as a crosslinking agent, 0.03 g of lithium phenyl (2,4,6-trimethylbenzoyl) phosphate as an initiator, and 0.012 g of curcumin as a light absorber to the clear solution, and mixing uniformly to obtain the gel material (0.012 g of curcumin was replaced by 0.012 g of Sudan in Comparative Example 6).

[0045] Test Example 1 Performance test

[0046] The gel materials prepared in Examples 1-6 and Comparative Examples 1-6 were respectively added to a light-cured 3D printing curing pool for printing, and the printed materials were tested for performance;

[0047] Printing method: the printed model was attached Figure 1 During the slicing process, the middle fixed beam was exposed only once, and after printing, post-processing was performed, and then the thickness of the middle fixed beam was measured by an optical microscope, and the average value was taken as the line printing precision.

[0048] Performance test method (compressive strength): 6x6x8 mm compression samples were printed, and a universal material tester was used for compression experiment with a compression rate of 4 mm / min, and the performance test results are shown in Table 2.

[0049] Table 2 Performance test results

[0050]

[0051] As can be seen from Table 2 (the value of / is too low), when acrylamide is used as solute and N-vinyl pyrrolidone is used as solvent, the performance of the gel material is enhanced with the increase of the amount of acrylamide added in the range of (2:8)-(3.5:6.5) (Examples 2-5), and the maximum printing precision can all meet the requirement of <50 um. The performance is the strongest when the amount of acrylamide and N-vinyl pyrrolidone added is 3.5:6.5, at which time the compression strength of the gel reaches 1538 MPa, and the maximum printing precision can reach 1 um level (as shown in Figure 2 Figure 2 is the SEM scanning diagram of the gel material when the amount of acrylamide and N-vinyl pyrrolidone added is 3.5:6.5, which confirms that the printing precision has reached about 1 um, which is the precision that most of the current hydrogels cannot reach).

[0052] With the further increase of the amount of acrylamide added (Example 6), the mixed solution of acrylamide and N-vinyl pyrrolidone becomes turbid (as shown in Figure 3 Figure 3 is the mixed solution of acrylamide and N-vinyl pyrrolidone: from left to right, Examples 2-6, it can be seen that the mixed solution of Example 6 has become turbid), the turbid solution is not conducive to the light-cured 3D printing, which will affect the distribution of light in the printing space and affect the printing performance.

[0053] Compared with Examples 1, Comparative Examples 1-3, and Comparative Examples 4-5, it can be seen that only the gel material prepared from the mixed solution in which acrylamide is used as solute and N-vinyl pyrrolidone is used as solvent can appear phase separation; Example 1 cannot appear phase separation without the addition of acrylamide, and Comparative Examples 1-3 use acrylic acid instead of acrylamide as solute; the gel materials obtained by using water or ethanol instead of N-vinyl pyrrolidone as solvent in Examples 4-5 cannot appear phase separation; the phase separation behavior regulates the spatial distribution of light, which can realize the efficient utilization of light and the regulation of the polymerization reaction of monomers, thereby improving the printing precision (for example, Example 4 and Comparative Example 3: under the condition that the ratio of solute and solvent is constant, the printing precision of Example 4 after the phase separation behavior appears is obviously reduced); thus, the printing precision of the gel material prepared by the mixed solution in which acrylamide is used as solute and N-vinyl pyrrolidone is used as solvent can be effectively reduced.

[0054] ​​Compared with Comparative Example 6, Example 5 shows that, at the same dosage, curcumin and Sudan are light absorbers. Obviously, curcumin has higher printing accuracy as a light absorber. In addition, Sudan itself has biotoxicity, which is not conducive to biological experiments, while curcumin, as a natural pigment, does not have the above-mentioned side effects.

[0055] Figure 4 The compression stress-strain curves were obtained for performance testing of the gel materials in the examples. In Examples 1, 4, and 5, the printed models were too soft to obtain effective compression stress-strain curves; while Example 6 was already a turbid liquid at room temperature. Figure 3 The components of Comparative Example 6 were not measured because they were difficult to use for photopolymerization 3D printing. The main components of Comparative Example 6 were the same as those of Example 5 (the only difference was the light absorber). As can be seen from the figure, within the range of (2:8) to (3.5:6.5) addition ratio of acrylamide to N-vinylpyrrolidone, the strain rate gradually increased with the increase of acrylamide addition, and the strain reached the maximum when the addition ratio was 3.5:6.5.

[0056] Transparency and transmittance test: A circular sheet with a diameter of 10mm and a thickness of 1mm was printed. A photograph of the sheet is attached. Figure 5 As shown, the transmittance of light at different wavelengths was then measured using a spectrometer. Figure 5 It can be seen that when the solution does not contain acrylamide, the circular flakes are relatively transparent and have high light transmittance (Example 1). As the content of acrylamide gradually increases, the whitening of the circular flakes increases significantly (Examples 2-5). In the spectrometer experiment, this is reflected in the gradual decrease of light transmittance. Therefore, we believe that the addition of acrylamide causes phase separation during the curing process, and the phase separation effect is enhanced as the content of acrylamide increases (curcumin was not added to any of the formulations when performing the spectrometer experiment).

[0057] 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-precision gel material for photopolymerization printing, characterized in that, Including acrylamide, N-vinylpyrrolidone, crosslinking agents, initiators, and light absorbers; The mass ratio of acrylamide to N-vinylpyrrolidone is 3.5:6.

5. The crosslinking agent is polyethylene glycol diacrylate, the initiator is lithium phenyl (2,4,6-trimethylbenzoyl) phosphate, and the light absorber is curcumin; The total mass ratio of acrylamide and N-vinylpyrrolidone to polyethylene glycol diacrylate, lithium phenyl (2,4,6-trimethylbenzoyl)phosphate, and curcumin is 1:0.02:0.003:0.0012.

2. The method for preparing high-precision photopolymerizable gel material according to claim 1, characterized in that, include: Acrylamide and N-vinylpyrrolidone were mixed and stirred to obtain a clear solution; A crosslinking agent, an initiator, and a light absorber are added to a clear solution and mixed thoroughly to obtain a high-precision gel material for photocuring printing.

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