Photosensitized 3D printing material and method for preparing the same

Abstract

The present application relates to a kind of photosensitization 3D printing consumables and its preparation method, belong to 3D printing technical field.The printing consumables is made of solution A and solution B according to 0.5~3 volume ratio;Solution A is made of the aqueous solution of AM with concentration of 0.4-2g / mL and photo initiator, photo initiator is 2-hydroxy-2-methyl propiophenone, 2-hydroxy-4'- (2-hydroxyethoxy) -2-methyl propiophenone or p-dimethylamino benzoic acid isooctyl ester, its mass is 0.02%~1% of the mass of AM;Solution B is made of the aqueous solution of high molecular polymer with concentration of 0.1-1g / mL and inorganic filling material, and inorganic filling material includes silicon dioxide, and its mass is 0.1%~60% of the mass of the polymer;The polymer is PVA with Mw of 1w-30w or PAA with Mw of 0.3w~300w.The device after the printing consumables solidification has good flexibility, self-healing and strength.

Description

Technical Field

[0001] This invention relates to a photosensitive 3D printing consumable and its preparation method, belonging to the field of 3D printing technology. Background Technology

[0002] 3D printing technology boasts advantages such as precise mold making and rapid manufacturing, and has broad application prospects in manufacturing, biomedicine, aerospace, and other fields. The working principle of 3D printing is to use a three-dimensional digital model as a basis, depositing and solidifying printable materials layer by layer to create a three-dimensional object. Based on different types of 3D printing technology, it can be divided into several categories, including stereolithography (SLA), selective laser sintering (SLS), and fused deposition modeling (FDM).

[0003] Stereopolymerization (SLA) is a 3D printing process that utilizes the principle of photosensitive resin curing under ultraviolet light. The specific process involves injecting photosensitive resin into a mold chamber. The path of ultraviolet light undergoes a photocuring reaction, forming a solid layer between the scraper and the resin. The scraper is then raised layer by layer while repeated ultraviolet light scanning, ultimately achieving a three-dimensional shape on the scraper.

[0004] Currently, 3D printing consumables used in SLA technology are typically photosensitive resin-based polymers. The resulting 3D model after photopolymerization is a rigid material. Due to the lack of flexibility in current 3D printing consumables after printing, they cannot be used in the field of flexible functional devices, such as flexible wearable pressure sensors and flexible electronic tattoos.

[0005] In the field of flexible device fabrication, polyacrylamide (PAM) is a commonly used material. Currently, in this field, the pursuit of flexible materials (hereinafter referred to as "printed parts") in flexible devices is usually to ensure flexibility and self-healing properties. The higher these two properties are, the less strong the printed parts are, which will lead to the printed parts being prone to breakage and damage.

[0006] Therefore, how to provide a photosensitive 3D printing consumable that can be used for SLA technology and can print parts with good flexibility, self-healing and strength is a technical problem that needs to be solved in this field. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a photosensitive 3D printing consumable and its preparation method. The printing consumable can be used in stereolithography (SLA) technology, and the printed and cured device not only has flexibility and self-healing properties, but also has good strength and can be used as a flexible tensile sensor.

[0008] To achieve the objectives of this invention, the following technical solutions are provided.

[0009] A photosensitive 3D printing consumable is composed of solution A and solution B in a volume ratio of (0.5-3):1;

[0010] Solution A consists of an aqueous solution of acrylamide monomer (AM) with a concentration of 0.4 g / mL to 2 g / mL and a photoinitiator, wherein the mass of the photoinitiator is 0.02% to 1% of the mass of AM in the AM aqueous solution;

[0011] Solution B is composed of an aqueous solution of a polymer with a concentration of 0.1 g / mL to 1 g / mL and an inorganic filler material, wherein the mass of the inorganic filler material is 0.1% to 60% of the mass of the polymer in the aqueous solution.

[0012] The polymer is polyvinyl alcohol (PVA) or polyacrylic acid (PAA); the average molecular weight (Mw) of the PVA is 10,000 to 300,000; the average molecular weight (Mw) of the PAA is 3,000 to 3,000,000.

[0013] The photoinitiator is 2-hydroxy-2-methylphenylacetone, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone, or isooctyl p-dimethylaminobenzoate;

[0014] The inorganic filler material includes silicon dioxide.

[0015] Preferably, the volume ratio of solution A to solution B is (0.7 to 2):1.

[0016] More preferably, the volume ratio of solution A to solution B is (0.7 to 1.2):1;

[0017] The concentration of AM in the acrylamide monomer (AM) aqueous solution is 0.8 g / mL to 1 g / mL, and the mass of the photoinitiator is 0.1% to 0.3% of the mass of AM in the AM aqueous solution;

[0018] The concentration of the polymer in the aqueous solution is 0.3 g / mL to 0.8 g / mL, and the mass of the inorganic filler is 3% to 60% of the mass of the polymer in the aqueous solution.

[0019] Preferably, the inorganic filler material further includes one or more of nickel powder, gold nanoparticles, and silver nanowires.

[0020] More preferably, the inorganic filler material is composed of silicon dioxide and nickel powder, wherein the mass of silicon dioxide is 1% to 10% of the mass of the polymer in the polymer aqueous solution, and the mass of nickel powder is 5% to 40% of the mass of the polymer in the polymer aqueous solution.

[0021] Preferably, the photoinitiator is 2-hydroxy-2-methylphenylacetone or 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone.

[0022] Preferably, the median particle size (D) of the nickel powder is... 50 The wavelength range is 10 nm to 2 μm.

[0023] Preferably, the median particle size (D) of the gold nanoparticles is... 50 The wavelength range is 10nm to 500nm.

[0024] Preferably, the silver nanowires have a diameter of 20 nm to 300 nm and a length of 10 μm to 200 μm.

[0025] Preferably, the median particle size (D) of the silica is... 50 The wavelength range is 10nm to 300nm.

[0026] A method for preparing the photosensitive 3D printing consumable according to the present invention, the steps of the method are as follows:

[0027] (1) Prepare the acrylamide monomer (AM) aqueous solution, add the photoinitiator to the AM aqueous solution, mix well to obtain solution A;

[0028] (2) Prepare the aqueous solution of the polymer, add the inorganic filler to the aqueous solution of the polymer, and mix evenly at 25℃~50℃ to obtain solution B;

[0029] (3) After mixing the solutions A and B evenly, degassing is performed to obtain the photosensitive 3D printing consumables.

[0030] Preferably, in step (2), the mixture is stirred evenly at a speed of 200 rpm to 2000 rpm.

[0031] Beneficial effects

[0032] (1) This invention provides a photosensitive 3D printing consumable. By controlling the volume ratio of solution A to solution B, the content of each component in the 3D printing consumable is controlled, so that the obtained printing consumable is not only suitable for SLA 3D printing, but also ensures that the printed device has good comprehensive performance such as flexibility, self-healing and strength.

[0033] Regarding flexibility, the acrylamide monomer in the 3D printing consumable forms polyacrylamide (PAM) after photocuring, which interweaves with PVA or PAA polymer molecules of a specific molecular weight to form an elastic structure. Therefore, the printed device is an elastic solid material with a high energy storage modulus. Thus, the 3D printing consumable can be used to print flexible devices with stretchability and elasticity.

[0034] Regarding self-healing properties, PVA and PAA polymers have a large number of hydrogen-bonded functional groups such as hydroxyl and carboxyl groups in their side chains. These functional groups have strong hydrogen bond interactions with the side chain amino groups of PAM obtained by AM photocuring reaction. Therefore, the materials obtained after photocuring and printing have strong self-healing ability (i.e., self-repair ability).

[0035] Regarding strength, the amount of polymer used in the 3D printing filament not only affects the self-healing properties of the printed device but also improves its strength, preventing tearing during application. Furthermore, the amount of polymer makes the filament suitable for SLA 3D printing.

[0036] The molecular weight of the polymer in the 3D printing consumable, especially the molecular weight of PVA, affects the viscosity of the 3D printing consumable. If the viscosity is too low, the printing will not be successful. Therefore, the molecular weight of the polymer in this invention ensures both the self-healing performance of the printed device and the ability of the 3D printing consumable to be used for SLA 3D printing to print a device with a complete structure.

[0037] The inorganic filler material includes silica, because the addition of silica gives the printed material a strong moisture retention capacity. In addition, the inorganic filler material can also be supplemented with corresponding functional additives according to application requirements.

[0038] (2) This invention provides a photosensitive 3D printing consumable. When the inorganic filler material also includes gold nanoparticles and silver nanowires, the printed material becomes conductive. When the inorganic filler material also includes nickel powder, the addition of nickel metal powder makes the printed material magnetic. At the same time, nickel powder, as a metal powder, is conductive, thus enabling the integration of a self-healing flexible sensor and actuator. In this way, the device can undergo different degrees of deformation in a magnetic field. The deformation leads to a change in resistance, and the change in resistance can generate a corresponding electrical signal. The degree of device deformation can be determined by the sensor after detecting the change in the electrical signal, thereby achieving the effect of monitoring the degree of device deformation.

[0039] (3) This invention provides a photosensitive 3D printing consumable, wherein the inorganic filler material is composed of silicon dioxide and nickel powder, thereby enabling the obtained device to better integrate a self-healing flexible sensor and actuator. Based on this, an intelligent actuator with motion self-sensing function can be developed, providing a new approach for developing self-healing actuators and sensors with arbitrary shapes.

[0040] (4) The present invention provides a photosensitive 3D printing consumable, further limiting the size of the inorganic filler material. The obtained 3D printing consumable is conducive to passing through the pinhole of the SLA 3D printer, without clogging the SLA 3D printer, thus ensuring the smooth progress of SLA 3D printing.

[0041] (5) The present invention provides a method for preparing photosensitive 3D printing consumables. The method is simple, which can be obtained by mixing solution A and solution B. Attached Figure Description

[0042] Figure 1 The results show the rheological properties of the 3D printing consumables prepared in Example 1.

[0043] Figure 2 (a) is a photograph of the "heart-shaped" elastic material printed by the 3D printing consumable prepared in Example 1 after it breaks; (b) is a photograph of the "heart-shaped" elastic material after it heals; (c) is an electron microscope image of the crack before healing after splicing the broken "heart-shaped" elastic material; and (d) is an electron microscope image of the crack disappearing after splicing and healing the broken "heart-shaped" elastic material.

[0044] Figure 3 This is a schematic diagram of the tensile response of a solid material printed using the 3D printing consumables prepared in Example 2.

[0045] Figure 4 (a) is a photograph of the cuboid elastic solid material obtained in Example 3 being attracted by a magnet; (b) is a photograph of the cuboid elastic solid material being released after the magnet is removed. Detailed Implementation

[0046] The present invention will be further described below with reference to specific embodiments. Unless otherwise specified, the methods described are conventional methods, and the raw materials described are available from publicly available commercial sources or prepared according to literature.

[0047] In the following embodiments:

[0048] The rheological properties were measured using a TA Instruments AR2000 rheometer.

[0049] The tensile force sensing test was performed using a CTM2000 electronic universal testing machine.

[0050] In the following embodiments, the average molecular weight of the PVA is 75,000; the median particle size (D) of the silica is... 50 The median particle size of the nickel powder is 30 nm; the silver nanowires have a diameter of 30 nm and a length of 20 μm; the median particle size of the nickel powder is 30 nm. 50The wavelength is 500nm.

[0051] Example 1

[0052] (1) Prepare an aqueous solution of acrylamide monomer (AM) with a concentration of 1 g / mL, add 2-hydroxy-2-methylphenylacetone to the AM aqueous solution, wherein the mass of 2-hydroxy-2-methylphenylacetone is 0.3% of the mass of AM, mix well to obtain solution A;

[0053] (2) Prepare a PVA aqueous solution with a concentration of 0.3 g / mL, add silica to the PVA aqueous solution, the mass of the silica being 3% of the mass of PVA in the PVA aqueous solution, mix evenly at 40°C by mechanical stirring at a stirring speed of 1000 rpm, and obtain solution B;

[0054] (3) After mixing the solutions A and B at a volume ratio of 0.7:1, centrifuge and degas the solution to obtain a photosensitive 3D printing consumable.

[0055] The 3D printing consumables prepared in this embodiment were tested as follows:

[0056] (1) The rheological properties of the 3D printing consumables prepared in this embodiment were tested, and the test results are shown in the figure. Figure 1 Therefore, it can be seen that the material has a high energy storage modulus platform, and the energy storage modulus is higher than the loss modulus, indicating that the 3D printing consumables prepared in this embodiment are 3D printed materials that are elastic solid materials.

[0057] (2) The 3D printing consumables prepared in this embodiment were used to print "heart-shaped" elastic material (also called "heart-shaped" gel) using a stereolithography (SLA) 3D printer. The printing speed was 2 mm / h, with each layer lasting 10 seconds. The ultraviolet wavelength was 405 nm, and the ultraviolet light intensity was 20 mW·cm. -2 Cut the printed heart-shaped elastic material, see... Figure 2 (a) is then reassembled, and the broken "heart-shaped" elastic material can self-heal within 2 minutes. Figure 2 (b) in the middle. Figure 2 As can be seen from (c) and (d) in the figure, the "heart-shaped" elastic material recovers its own tensile strength after healing, indicating that the "heart-shaped" elastic material has good self-healing ability. The principle is that there are strong intermolecular hydrogen bonds between the amino groups in the PAM molecules formed by AM photocuring and the hydroxyl groups in the PVA molecules. Therefore, when the fracture surfaces come into contact, chemical bonds are spontaneously formed to achieve the purpose of self-healing.

[0058] (3) The 3D printing consumables prepared in this embodiment were used to print dumbbell-shaped elastic material (also known as dumbbell-shaped gel) using an SLA 3D printer. The printing speed was 2 mm / h, and each layer was printed in 10 s. The ultraviolet wavelength was 405 nm, and the ultraviolet light intensity was 20 mW·cm. -2 Using a CTM2000 electronic universal testing machine at a tensile speed of 100 mm / min, the strength of the dumbbell-shaped elastic material was measured to be 11.3 MPa. This indicates that the printed elastic material not only has good flexibility and self-healing properties, but also good strength.

[0059] Example 2

[0060] (1) Prepare an aqueous solution of acrylamide monomer (AM) with a concentration of 0.8 g / mL, add 2-hydroxy-2-methylphenylacetone to the AM aqueous solution, wherein the mass of 2-hydroxy-2-methylphenylacetone is 0.2% of the mass of AM, mix well to obtain solution A;

[0061] (2) Prepare a PVA aqueous solution with a concentration of 0.6 g / mL. Add silica and silver nanowires to the PVA aqueous solution. The mass of silica is 20% of the mass of PVA in the PVA aqueous solution, and the mass of silver nanowires is 40% of the mass of PVA in the PVA aqueous solution. Mix evenly at 50°C by mechanical stirring at a stirring rate of 1200 rpm to obtain solution B.

[0062] (3) After mixing the solutions A and B in a volume ratio of 1:1, centrifuge and degas the solution to obtain a photosensitive 3D printing consumable.

[0063] The 3D printing consumables prepared in this embodiment were tested as follows:

[0064] (1) The rheological properties of the 3D printing consumables prepared in this embodiment were tested. According to the test results, the material has a high storage modulus plateau, and the storage modulus is higher than the loss modulus, indicating that the material obtained after 3D printing is an elastic solid material. Furthermore, due to the strong intermolecular hydrogen bonds between the amino groups in the PAM molecules formed by AM photocuring and the hydroxyl groups in the PVA molecules, chemical bonds are spontaneously formed at the contact surfaces to achieve a self-healing effect.

[0065] (2) The 3D printing filament prepared in this embodiment was used to print dumbbell-shaped elastic solid material using an SLA 3D printer. The printing speed was 1 mm / h, and each layer was printed in 10 s. The ultraviolet light wavelength was 405 nm, and the ultraviolet light intensity was 20 mW·cm. -2 Tensile force sensing tests were performed on the printed solid material, and the test results are shown below. Figure 3Therefore, it can be seen that the resistance value of the solid material changes with the stretching length, that is, the resistance value of the solid material increases with the increase of the stretching length, indicating that the solid material has conductivity and tensile properties, and has a good tensile sensing effect. This further demonstrates that the 3D printing consumables prepared in this embodiment have the function of directly printing tensile sensors.

[0066] (3) The 3D printing filament prepared in this embodiment was used to print dumbbell-shaped elastic material using an SLA 3D printer. The printing speed was 2 mm / h, and each layer was printed in 10 s. The ultraviolet light wavelength was 405 nm, and the ultraviolet light intensity was 20 mW·cm. -2 Using a CTM2000 electronic universal testing machine at a tensile speed of 100 mm / min, the strength of the dumbbell-shaped elastic material was measured to be 10.6 MPa. This indicates that the printed elastic material not only has good flexibility and self-healing properties, but also good strength.

[0067] Example 3

[0068] (1) Prepare an aqueous solution of acrylamide monomer (AM) with a concentration of 1 g / mL, add 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone to the AM aqueous solution, wherein the mass of 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone is 0.1% of the mass of AM, mix well to obtain solution A;

[0069] (2) Prepare a PVA aqueous solution with a concentration of 0.8 g / mL. Add silicon dioxide and nickel powder to the PVA aqueous solution. The mass of silicon dioxide is 10% of the mass of PVA in the PVA aqueous solution, and the mass of nickel powder is 40% of the mass of PVA in the PVA aqueous solution. Mix evenly at 50°C by mechanical stirring at a stirring speed of 1500 rpm to obtain solution B.

[0070] (3) After mixing the solutions A and B at a volume ratio of 1.2:1, centrifuge and degas the solution to obtain a photosensitive 3D printing consumable.

[0071] The 3D printing consumables prepared in this embodiment were tested as follows:

[0072] (1) The rheological properties of the 3D printing consumables prepared in this embodiment were tested. According to the test results, the material has a high storage modulus plateau, and the storage modulus is higher than the loss modulus, indicating that the material obtained after 3D printing is an elastic solid material. Furthermore, due to the strong intermolecular hydrogen bonds between the amino groups in the PAM molecules formed by AM photocuring and the hydroxyl groups in the PVA molecules, chemical bonds are spontaneously formed at the contact surfaces to achieve a self-healing effect.

[0073] (2) The 3D printing filament prepared in this embodiment was used to print a rectangular elastic solid material using an SLA 3D printer. The printing speed was 3 mm / h, and the layer length was 8 s. The ultraviolet wavelength was 405 nm, and the ultraviolet light intensity was 20 mW·cm. -2 The magnetic response of the printed solid material was tested, and the results are shown in [the table below]. Figure 4 , Figure 4 (a) shows how a rectangular elastic solid material is attracted to the inner bottom surface of a bottle by a magnet when a magnetic field is brought near. Figure 4 (b) shows that after the magnet is removed, the cuboid elastic solid material is released and falls to the bottle opening, demonstrating that the 3D printing consumable prepared in this embodiment has magnetic responsiveness and can achieve a driving effect under the action of a magnetic field. This further illustrates that the 3D printing consumable of this embodiment can directly print magnetically responsive materials, enabling the integration of self-healing flexible sensors and actuators.

[0074] (3) The 3D printing filament prepared in this embodiment was used to print dumbbell-shaped elastic material using an SLA 3D printer. The printing speed was 2 mm / h, and each layer was printed in 10 s. The ultraviolet light wavelength was 405 nm, and the ultraviolet light intensity was 20 mW·cm. -2 Using a CTM2000 electronic universal testing machine at a tensile speed of 100 mm / min, the strength of the dumbbell-shaped elastic material was measured to be 9.7 MPa. This indicates that the printed elastic material not only has good flexibility and self-healing properties, but also good strength.

[0075] This invention includes, but is not limited to, the above embodiments. Any equivalent substitutions or partial improvements made under the spirit and principles of this invention shall be considered within the scope of protection of this invention.

Claims

1. A photosensitive 3D printing consumable, characterized in that: The printing consumables are composed of solution A and solution B in a volume ratio of (0.7-1.2):1; Solution A consists of an AM aqueous solution with a concentration of 0.8 g / mL to 1 g / mL and a photoinitiator, wherein the mass of the photoinitiator is 0.1% to 0.3% of the mass of AM in the AM aqueous solution; Solution B is composed of an aqueous solution of a polymer with a concentration of 0.3 g / mL to 0.8 g / mL and an inorganic filler material, wherein the mass of the inorganic filler material is 3% to 60% of the mass of the polymer in the aqueous solution. The polymer is PVA or PAA; the average molecular weight of PVA is 10,000 to 300,000; the average molecular weight of PAA is 3,000 to 3,000,000. The photoinitiator is 2-hydroxy-2-methylphenylacetone, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone, or isooctyl p-dimethylaminobenzoate; The inorganic filler material includes silicon dioxide.

2. The photosensitive 3D printing consumable according to claim 1, characterized in that: The inorganic filler material also includes one or more of nickel powder, gold nanoparticles, and silver nanowires.

3. The photosensitive 3D printing consumable according to claim 2, characterized in that: The inorganic filler material is composed of silicon dioxide and nickel powder, wherein the mass of silicon dioxide is 1% to 10% of the mass of the polymer in the polymer aqueous solution, and the mass of nickel powder is 5% to 40% of the mass of the polymer in the polymer aqueous solution.

4. The photosensitive 3D printing consumable according to claim 3, characterized in that: The photoinitiator is 2-hydroxy-2-methylphenylacetone or 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylphenylacetone.

5. A photosensitive 3D printing consumable according to claim 4, characterized in that: The median particle size of the nickel powder is 10 nm to 2 μm; the median particle size of the gold nanoparticles is 10 nm to 500 nm; the diameter of the silver nanowires is 20 nm to 300 nm and the length is 10 μm to 200 μm; the median particle size of the silicon dioxide is 10 nm to 300 nm.

6. A method for preparing a photosensitive 3D printing consumable as described in any one of claims 1 to 5, characterized in that: The steps of the method are as follows: (1) Prepare the AM aqueous solution, add the photoinitiator to the AM aqueous solution, mix well to obtain solution A; (2) Prepare the aqueous solution of the polymer, add the inorganic filler to the aqueous solution of the polymer, and mix evenly at 25℃~50℃ to obtain solution B; (3) After mixing the solutions A and B evenly, degassing is performed to obtain the photosensitive 3D printing consumables.

7. The method for preparing a photosensitive 3D printing consumable according to claim 6, characterized in that: In step (2), the mixture is stirred evenly at a speed of 200 rpm to 2000 rpm.

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