An underwater self-healing light-curing 3D printing elastomer and its preparation method and application

Abstract

The present invention belongs to the technical field of 3D printing materials, and discloses a self-healing underwater light-cured 3D printing elastomer and its preparation method and application. The raw material components of the light-cured 3D printing elastomer include a hydrophobic acrylate monomer, a fluorinated acrylate monomer, a photoinitiator, and an auxiliary agent; the hydrophobic acrylate monomer is selected from at least one of benzyl acrylate and isobornyl acrylate; the fluorinated acrylate monomer is selected from at least one of 2,2,2-trifluoroethyl acrylate and 1H,1H,2H,2H-perfluorooctanol acrylate. Based on the specific hydrophobic acrylate monomer and the polymer network formed by the fluorinated acrylate monomer, there is a dipole-dipole interaction, so that the light-cured 3D printing elastomer can have self-healing ability under room temperature water, and the self-healing ability can be achieved without the stimulation of special conditions (such as heating or laser irradiation).

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing materials, and in particular relates to an underwater self-healing light-cured 3D printing elastomer and a preparation method and application thereof. Background Art

[0002] The key difference between soft robots and rigid robots is that they are primarily made of soft materials, and their movement relies on the deformation of the soft robot itself. Compared to traditional robots, which often suffer from poor environmental adaptability and bulk, soft robots are increasingly valued for their inherent flexibility, excellent compliance, excellent adaptability, and naturally safe interactivity, demonstrating enormous potential for development in fields such as healthcare, education, services, rescue, exploration, detection, and wearable devices.

[0003] Currently, the production of soft robots primarily relies on methods such as machining and casting. These processes are cumbersome and time-consuming, and the sealed connection structures require a considerable amount of space and mass. This also presents challenges in the miniaturization and integrated design of soft robots. Compared to traditional manufacturing methods, 3D printing technology based on Digital Light Processing (DLP) offers higher molding precision and can rapidly construct complex three-dimensional structures, facilitating the manufacture of soft robots.

[0004] Due to the unique mechanical properties of soft materials, soft robots are able to adapt to various unstructured environments. However, in practical applications, soft robots often face complex environments such as underwater operations. Soft materials are very easy to damage during use, making them unusable. The emergence of self-healing materials has made it possible for soft robots to continue to be used after damage. Compared with traditional materials, self-healing materials show the ability to self-repair when broken or damaged by fatigue. However, most current 3D-printed soft robots still rely on commercial elastomers, which lack the ability to self-heal underwater. Even small defects or puncture wounds can cause devastating damage to soft robots.

[0005] Therefore, providing elastomers that can self-heal underwater at room temperature and can be photocured 3D printed is of great significance to the development of soft robots. Summary of the Invention

[0006] The present invention aims to address at least one of the technical problems existing in the aforementioned prior art. To this end, the present invention provides a self-healing underwater photocurable 3D-printed elastomer, as well as its preparation method and application. The photocurable 3D-printed elastomer described in the present invention can be formed by photocuring and can self-heal underwater without requiring special conditions (such as light exposure), achieving a repair efficiency exceeding 95%.

[0007] The inventive concept of the present invention: The present invention selects specific hydrophobic acrylate monomers and fluorinated acrylate monomers, and combines them with photoinitiators and additives, so that the light-cured 3D printed elastomer of the present invention can not only perform efficient light-curing printing, but also based on the polymer network formed by the specific hydrophobic acrylate monomers and fluorinated acrylate monomers, there is a dipole-dipole interaction, so that the light-cured 3D printed elastomer can have self-healing ability under room temperature water, and this self-healing ability can be achieved without the stimulation of special conditions (such as heating, laser irradiation). It can also maintain a stable room temperature self-healing effect in an aqueous environment. It greatly expands the application of light-cured 3D elastomers. The elongation at break of the light-cured 3D printed elastomer of the present invention is greater than 260%. After the material is broken, the material can be repaired in a room temperature environment and a room temperature water environment without the need for external stimulation, and the repair efficiency is above 95%.

[0008] In addition, the photocuring efficiency of a single fluorinated acrylate monomer is relatively slow and cannot meet the requirements of 3D printing. The hydrophobic acrylic monomer selected for use in the present invention also helps to improve the photocuring efficiency of the photosensitive resin system.

[0009] A first aspect of the present invention provides an underwater self-healing light-cured 3D printed elastomer.

[0010] Specifically, an underwater self-healing light-curing 3D printing elastomer, the raw material components include a hydrophobic acrylate monomer, a fluorine-containing acrylate monomer, a photoinitiator, and an auxiliary agent;

[0011] The hydrophobic acrylate monomer is selected from at least one of benzyl acrylate and isobornyl acrylate;

[0012] The fluorine-containing acrylate monomer is selected from at least one of 2,2,2-trifluoroethyl acrylate and 1H,1H,2H,2H-perfluorooctanol acrylate.

[0013] Preferably, the auxiliary agent includes a cross-linking agent and / or a light absorber.

[0014] Preferably, the cross-linking agent is selected from at least one of polyethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, and pentaerythritol tetraacrylate.

[0015] Preferably, the photoinitiator is selected from at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1-hydroxycyclohexylphenyl ketone.

[0016] Preferably, the light absorber is selected from at least one of Sudan Orange G, Sudan I, quercetin and Marseille Yellow.

[0017] Preferably, the raw material components of the light-curing 3D printing elastomer include 8 to 38 parts of hydrophobic acrylate monomer, 60 to 95 parts of fluorine-containing acrylate monomer, 0.5 to 2.5 parts of photoinitiator, and 0.1 to 1 part of auxiliary agent, by weight; further preferably, the raw material components of the light-curing 3D printing elastomer include 10 to 30 parts of hydrophobic acrylate monomer, 70 to 90 parts of fluorine-containing acrylate monomer, 0.5 to 2 parts of photoinitiator, and 0.12 to 0.6 parts of auxiliary agent, by weight.

[0018] Preferably, the raw material components of the light-curable 3D printing elastomer include, by weight, 10-30 parts of a hydrophobic acrylate monomer, 70-90 parts of a fluorinated acrylate monomer, 0.1-0.5 parts of a crosslinker, 0.5-2 parts of a photoinitiator, and 0.02-0.1 parts of a light absorber. A suitable ratio of these components helps to obtain a light-curable 3D printing elastomer with better performance.

[0019] A second aspect of the present invention provides a method for preparing an underwater self-healing light-cured 3D printed elastomer.

[0020] Specifically, a method for preparing an underwater self-healing light-cured 3D printed elastomer includes the following steps:

[0021] The raw material components are mixed and light-cured to obtain the light-cured 3D printed elastomer.

[0022] Preferably, the preparation method comprises the following steps:

[0023] The fluorine-containing acrylate monomer and the hydrophobic acrylate monomer are stirred and mixed, and then a cross-linking agent is added and stirred, and then a photoinitiator and a light absorber are added, stirred and dissolved, and light-cured to obtain the light-cured 3D printing elastomer.

[0024] A third aspect of the present invention provides an application of an underwater self-healing light-cured 3D printed elastomer.

[0025] A soft robot is prepared from the above-mentioned light-cured 3D printed elastomer.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention selects specific hydrophobic acrylate monomers and fluorinated acrylate monomers, and combines them with photoinitiators and additives, so that the light-cured 3D printed elastomer of the present invention can not only be efficiently photocured, but also based on the polymer network formed by the specific hydrophobic acrylate monomers and fluorinated acrylate monomers, there is a dipole-dipole interaction, so that the light-cured 3D printed elastomer can have self-healing ability under room temperature water, and this self-healing ability can be achieved without the stimulation of special conditions (such as heating, laser irradiation). It can also maintain a stable room temperature self-healing effect in an aqueous environment. It greatly expands the application of light-cured 3D elastomers. The elongation at break of the light-cured 3D printed elastomer of the present invention is greater than 260%. After the material is broken, it can be repaired in a room temperature environment and a room temperature water environment without the need for external stimulation, and the repair efficiency is above 95%.

[0028] (2) The light-cured 3D printed elastomer of the present invention has good stability in an underwater environment and does not require external stimulation. The elastomer can also self-heal in an underwater environment, and its mechanical properties can basically be restored to their initial state.

[0029] (3) The light-cured 3D printed elastomer described in the present invention has good stretchability (>260%) and can meet the deformation requirements of soft robots.

[0030] (4) The light-curing 3D printing elastomer of the present invention has a low viscosity raw material photosensitive resin system and can be quickly cured under 405nm or 385nm light. It is suitable for common light-curing 3D printing equipment on the market and has high printing structure accuracy.

[0031] (5) The light-curing 3D-printed elastomer described in the present invention is highly compatible with DLP 3D printing and can rapidly construct complex, high-precision three-dimensional structures. Pneumatic soft actuators 3D-printed with light-curing elastomers can operate stably underwater. After being damaged, the actuator structure can self-heal underwater and continue to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The photorheological curves of the light-cured 3D printed elastomers of Example 1 and Comparative Example 1 of the present invention are shown;

[0033] Figure 2 This is a self-healing optical image of the light-cured 3D printed elastomer in Example 1 of the present invention;

[0034] Figure 3 The self-healing mechanical properties characterization results of the light-cured 3D printed elastomer in Example 1 of the present invention;

[0035] Figure 4The self-healing mechanical properties of the light-cured 3D-printed elastomer under water are characterized in Example 1 of the present invention.

[0036] Figure 5 This is a picture of the underwater self-healing of the 3D printed structure of the light-cured 3D printed elastomer in Example 1 of the present invention;

[0037] Figure 6 This is a self-healing picture of the soft actuator of the light-cured 3D-printed elastomer 3D printed in an aqueous environment in Example 1 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.

[0039] Unless otherwise specified, the raw materials, reagents, or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0040] Example 1: Preparation of light-cured 3D printed elastomer

[0041] The invention discloses an underwater self-healing light-curing 3D printing elastomer. The raw material components, calculated by weight, are 20 parts of isobornyl acrylate, 78.4 parts of 1H,1H,2H,2H-perfluorooctanol acrylate, 0.5 parts of allyl isocyanurate, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 0.1 parts of Sudan I, a light absorber.

[0042] A method for preparing an underwater self-healing light-cured 3D printed elastomer comprises the following steps:

[0043] 1H,1H,2H,2H-perfluorooctanol acrylate and isobornyl acrylate are stirred and mixed evenly, and then allyl isocyanurate is added and stirred and mixed evenly to obtain a mixed solution; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and light absorber Sudan I are further added and stirred until completely dissolved to obtain a photosensitive resin liquid; the photosensitive resin liquid is poured into a resin tank of a 3D printing device with a 385nm light source for model printing. After printing is completed, the sample is placed in a UV box and cured for 10 minutes to obtain a light-cured 3D printed elastomer.

[0044] The elongation at break of the light-cured 3D-printed elastomer obtained in this embodiment is 270%, and the glass transition temperature is -15°C.

[0045] Comparative Example 1

[0046] This comparative example 1 provides a photocurable resin that does not contain a hydrophobic acrylic monomer, and the preparation method thereof is as follows: 98.4 parts of 1H,1H,2H,2H-perfluorooctanol acrylate are added, 0.5 parts of a crosslinking agent allyl isocyanurate are added, and the mixture is stirred evenly to obtain a mixed solution; 1 part of a photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 0.1 parts of a light absorber Sudan I are added, and the mixture is stirred until completely dissolved to obtain a photocurable resin.

[0047] The photocurable 3D printing elastomer prepared in Example 1 and the photocurable resin without hydrophobic acrylic monomer prepared in Comparative Example 1 were subjected to photorheological characterization. The changes in the storage modulus and loss modulus of the samples were used to reflect the entire photocuring process. The intersection of the storage modulus and loss modulus was defined as the gel point, which can be used to quantify the speed of the photocuring process. Figure 1 (“Modulus” represents modulus, and “Time” represents time) as shown in the figure, the light-cured 3D printed elastomer in Example 1 reaches the gel point earlier, and the light-curing speed is significantly improved.

[0048] The self-healing ability of the light-cured 3D printed elastomer prepared in Example 1 was tested.

[0049] Figure 2 This is a self-healing optical image of the light-cured 3D printed elastomer in Example 1 of the present invention; Figure 2 Before and after healing of light-cured 3D printed elastomers ( Figure 2 The optical microscope picture ("a" represents before healing and "b" represents after healing) shows that after 24 hours of healing, the internal incision of the light-cured 3D printed elastomer has completely disappeared, confirming the good self-healing properties of the light-cured 3D printed elastomer.

[0050] Figure 3 The self-healing mechanical properties characterization results of the light-cured 3D printed elastomer in Example 1 of the present invention; Figure 3 It was measured under the conditions that the length of the light-curing 3D printed elastomer spline was 10 mm, the width was 5 mm, the thickness was 1 mm, and the tensile speed was 10 mm / min.

[0051] Depend on Figure 3 (The horizontal axis "Strain" represents the elongation at break, the vertical axis "Stress" represents the fracture strength, and "Original" represents the initial state of the light-cured 3D printed elastomer, that is, the state without cracks.) It can be seen that with the extension of the healing time (from 30 minutes to 24 hours), the elongation at break and the fracture strength of the light-cured 3D printed elastomer gradually recovered. After 24 hours of healing, the toughness and elongation at break of the light-cured 3D printed elastomer can basically be restored to the initial state.

[0052] Figure 4The self-healing mechanical properties of the light-cured 3D printed elastomer under water are characterized by Example 1 of the present invention; Figure 4 (“Strain” indicates elongation at break, “Stress” indicates strength at break, “Original” indicates the initial state of the photocurable 3D printed elastomer, i.e., the state without cracks, and “in water” indicates being in water) It can be seen that after 24 hours of healing in an underwater environment, the strength and elongation at break of the photocurable 3D printed elastomer can basically be restored to their original state.

[0053] Figure 5 This is an underwater self-healing picture of the 3D printed structure of the light-cured 3D printed elastomer in Example 1 of the present invention; Figure 5 ("a" is a structure 3D printed using the light-curing 3D printed elastomer of Example 1, "b" is two printed structures spliced ​​together in water, "c" is the state of two printed structures being placed underwater for 24 hours after being spliced ​​together, and "d" and "e" are printed structures that can be assembled into a new structure through self-healing splicing after being spliced ​​together, and the interface between the structures will not be destroyed during the stretching process) It can be seen that the light-curing 3D printed elastomer has good 3D printability, and the 3D printed structures can also be assembled into a new structure through self-healing splicing.

[0054] Figure 6 This is a self-healing picture of the soft actuator of the 3D-printed elastomer of the first embodiment of the present invention in a water environment; Figure 6 ("a" and "b" are soft drives 3D-printed using the light-curing 3D-printed elastomer of Example 1, "c" and "d" are 3D-printed soft drives that can be driven underwater, "e" is a 3D-printed soft drive that cannot be driven after being damaged, and "f" is a 3D-printed soft drive that can continue to drive after being healed; "Original" represents the initial state of the light-curing 3D-printed elastomer, that is, a state without cracks, "Bending" represents a bent soft drive, "Damaged" represents a damaged soft drive, and "Healed" represents a soft drive after self-healing) It can be seen that after the 3D-printed soft drive is damaged, it can self-heal in an aqueous environment and continue to drive.

[0055] Example 2: Preparation of light-cured 3D printed elastomer

[0056] The invention discloses an underwater self-healing light-curing 3D printing elastomer. The raw material components thereof are, by weight, 30 parts of benzyl acrylate, 68.8 parts of 1H,1H,2H,2H-perfluorooctanol acrylate, 0.1 part of polyethylene glycol diacrylate, 1 part of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 0.1 part of Sudan orange as a light absorber.

[0057] A method for preparing an underwater self-healing light-cured 3D printed elastomer comprises the following steps:

[0058] 1H,1H,2H,2H-perfluorooctanol acrylate and benzyl acrylate are stirred and mixed evenly, and then polyethylene glycol diacrylate is added and stirred and mixed evenly to obtain a mixed solution; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and a light absorber, Sudan Orange, are then added and stirred until completely dissolved to obtain a photosensitive resin liquid; the photosensitive resin liquid is poured into a resin tank of a 3D printing device with a 385nm light source for model printing. After printing is completed, the sample is placed in a UV box and cured for 10 minutes to obtain a light-cured 3D printed elastomer.

[0059] Example 3: Preparation of light-cured 3D printed elastomer

[0060] The invention discloses an underwater self-healing light-curing 3D printing elastomer. The raw material components are, by weight, 15 parts of isobornyl acrylate, 72.6 parts of 2,2,2-trifluoroethyl acrylate, 0.3 parts of ethoxylated trimethylolpropane triacrylate, 2 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 0.1 parts of Sudan orange as a light absorber.

[0061] A method for preparing an underwater self-healing light-cured 3D printed elastomer comprises the following steps:

[0062] 2,2,2-Trifluoroethyl acrylate and isobornyl acrylate are stirred and mixed evenly, and then ethoxylated trimethylolpropane triacrylate is added and stirred and mixed evenly to obtain a mixed solution; 2-hydroxy-2-methyl-1-phenyl-1-propanone and a light absorber, Sudan Orange, are then added and stirred until completely dissolved to obtain a photosensitive resin liquid; the photosensitive resin liquid is poured into a resin tank of a 3D printing device with a 385nm light source for model printing. After printing is completed, the sample is placed in a UV box and cured for 10 minutes to obtain a light-cured 3D printed elastomer.

Claims

1. A light-cured 3D printed elastomer, characterized in that: The raw material components of the light-curable 3D printing elastomer are as follows: 8-38 parts of hydrophobic acrylate monomer, 60-95 parts of fluorine-containing acrylate monomer, 0.5-2.5 parts of photoinitiator, 0.1-0.5 parts of cross-linking agent, 0.02-0.1 parts of light absorber; The hydrophobic acrylate monomer is selected from at least one of benzyl acrylate and isobornyl acrylate; The fluorine-containing acrylate monomer is selected from at least one of 2,2,2-trifluoroethyl acrylate and 1H,1H,2H,2H-perfluorooctanol acrylate; The cross-linking agent is selected from at least one of polyethylene glycol diacrylate, 1,6-hexanediol dimethacrylate, triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, and pentaerythritol tetraacrylate; The photoinitiator is selected from at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 1-hydroxycyclohexyl phenyl ketone; The light absorber is selected from at least one of Sudan Orange G, Sudan I, quercetin and Marseille Yellow.

2. The light-cured 3D printing elastomer according to claim 1, characterized in that: The light-curable 3D printing elastomer comprises, by weight, 10 to 30 parts of a hydrophobic acrylate monomer, 70 to 90 parts of a fluorine-containing acrylate monomer, 0.1 to 0.5 parts of a cross-linking agent, 0.5 to 2 parts of a photoinitiator, and 0.02 to 0.1 parts of a light absorber.

3. The method for preparing a light-cured 3D printing elastomer according to claim 1 or 2, characterized in that: The following steps are involved: The raw material components are mixed and light-cured to obtain the light-cured 3D printed elastomer.

4. The preparation method according to claim 3, characterized in that The following steps are involved: The fluorine-containing acrylate monomer and the hydrophobic acrylate monomer are stirred and mixed, and then a cross-linking agent is added and stirred, and then a photoinitiator and a light absorber are added, stirred and dissolved, and light-cured to obtain the light-cured 3D printing elastomer.

5. A soft robot, characterized in that: Prepared from the light-cured 3D printing elastomer according to claim 1 or 2.

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