A gel precursor composition based on photocuring crosslinking and its applications

Abstract

The present invention discloses a gel precursor composition based on photocuring cross-linking and its application, the gel precursor composition comprises, by weight, 15 to 35 parts of isooctyl acrylate, 25 to 40 parts of 4-acryloylmorpholine, 0.5 to 1 part of photoinitiator, and 30 to 50 parts of cross-linking agent. The present invention also provides a gel prepared by the above-mentioned gel precursor composition, and the preparation method comprises the following steps: mixing and stirring the components to obtain a gel precursor solution; cross-linking and curing the gel precursor solution under ultraviolet light to obtain a gel. The gel in the present invention has multiple characteristics of simple preparation, body temperature triggering, high-strength mechanics and biocompatibility, and has potential application value in biomedical materials.

Description

Technical Field

[0001] The present invention relates to the technical field of biomaterials, and particularly relates to a gel precursor composition based on photocuring crosslinking and its application. Background Art

[0002] Shape memory is the ability of a material to recover its original shape from other deformed shapes when a specific stimulus is applied. A polymer with a shape memory effect is a shape memory polymer (SMP).

[0003] In patent applications related to shape memory polymer materials, polyurethane, epoxy resin, and polyolefin account for a relatively large proportion, and among them, the research on polyurethane materials is the most in-depth. CN201911364976.6 prepared a body temperature-responsive polyurethane material based on poly(ε-caprolactone) diol using a chemical crosslinking method, but the preparation process is relatively complex, and the reaction time usually takes several hours, resulting in low preparation efficiency. The shape memory polyurethane material proposed in CN201210062393X can only deform under the stimulation of an external magnetic field or electric field, and its in vivo application function is insufficient. In addition to polyurethane materials, polyester materials can also obtain shape memory functions through peroxide crosslinking or radiation crosslinking. However, its disadvantages are also obvious. It usually cannot resist hot water, making it difficult to be used as a biomaterial in vivo.

[0004] Currently, the mechanical properties of most shape memory gels are usually in the order of kilopascals. The team of Liu Wenguang from Tianjin University prepared a thermoresponsive polyacrylonitrile (PAN)-polyacrylamide (PAAm)-polyethylene glycol (PEG3kDMA) shape memory hydrogel based on dipole-dipole enhanced phase inversion method. Its mechanical properties can also be enhanced by dipole pairing and hydrogen bonding, obtaining a mechanical modulus at the megapascal level and can be triggered at body temperature. However, its relatively complex solution polymerization-based synthesis process can usually only produce relatively simple sample structures, which are not suitable for complex models and cannot meet large-scale industrial production. In order to fabricate more complex shape memory models, the team of Ge Qi from Southern University of Science and Technology used aliphatic polyurethane acrylate (AUD) to prepare a high-strength, digital light processing (DLP)-based 4D printed shape memory polymer. However, it is reported that its triggering temperature is about 80 °C, much higher than body temperature. Summary of the Invention

[0005] In view of the problems of the existing preparation process of shape memory polymers, which is complex and difficult to be applied to complex structures and large-scale production, has too high deformation stimulation temperature, and poor mechanical properties, the present invention provides a gel precursor composition based on photocuring crosslinking and its application. Compared with the hydrogels with high water content in the prior art, this gel overcomes the problem of material brittleness, increases the mechanical modulus from the kilopascal level to the megapascal level, and reduces the fracture risk of the cured material. In addition, this organic gel also has rapid photocurability, and its photocuring crosslinking reaction based on bulk polymerization can be completed within a few seconds, and the shape recovery process only takes dozens of seconds. In addition, the preparation process of this hydrogel is simple and easy to implement, and can meet the requirements of complex structures and large-scale production. At the same time, its body temperature triggering property enables it to be applied in the body, and it also exhibits sufficient chemical stability and biocompatibility.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] On the one hand, the present invention provides a gel precursor composition based on photocuring crosslinking, which includes, by weight: 15-35 parts of isooctyl acrylate (2-EHA), 25-40 parts of 4-acryloylmorpholine (ACMO), 0.5-1 part of photoinitiator, and 30-50 parts of crosslinking agent.

[0008] In some specific embodiments, the mass fraction of the isooctyl acrylate (2-EHA) is 15 parts, 20 parts, 25 parts, 30 parts, 35 parts or any fraction therebetween.

[0009] In some specific embodiments, the mass fraction of the 4-acryloylmorpholine (ACMO) is 25 parts, 30 parts, 35 parts, 40 parts or any fraction therebetween.

[0010] In some specific embodiments, the mass fraction of the photoinitiator is 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts or any fraction therebetween.

[0011] In some specific embodiments, the mass fraction of the crosslinking agent is 30 parts, 35 parts, 40 parts, 45 parts, 50 parts or any fraction therebetween.

[0012] As a preferred embodiment, the photoinitiator is dihydro-4,4-dimethyl-2,3-furandione (DDFD).

[0013] As a preferred embodiment, the crosslinking agent is polyurethane acrylate (TAPUA).

[0014] As a preferred embodiment, it further includes a solvent; the solvent is preferably water; the mass fraction of the solvent in the gel precursor composition is ≤20%.

[0015] In another aspect, the present invention provides a gel prepared from the above gel composition, wherein the preparation comprises the following steps:

[0016] The components are mixed and stirred thoroughly to obtain a gel precursor solution;

[0017] The gel is obtained by cross-linking and curing the gel precursor solution under ultraviolet light.

[0018] As a preferred embodiment, the wavelength of the ultraviolet light is 365-405 nm;

[0019] Preferably, the cross-linking and curing time is 2 to 5 seconds.

[0020] In another aspect, the present invention provides use of the above gel in preparing shape memory materials, preferably, use of the gel in preparing biomedical materials.

[0021] In the technical solution of the present invention, the gel is in a permanent state of relaxed blocks at room temperature of about 20°C, showing plasticity. The gel can be pre-programmed into different shapes, at which time the gel is in a temporary state, the blocks are stretched, and show elasticity. Under external thermal stimulation (38°C), the gel can recover from the pre-programmed shape to its permanent shape.

[0022] The above technical solution has the following advantages or beneficial effects:

[0023] The gel composition provided by the present invention comprises three components: a photoinitiator, a crosslinking agent and a monomer; wherein isooctyl acrylate and 4-acryloylmorpholine are used as monomers to form a gel skeleton through a polymerization reaction, and the crosslinking agent can be diluted at the same time so that the gel precursor solution meets the viscosity requirement of subsequent sample preparation; the photoinitiator is used to initiate the polymerization reaction; the present invention can adopt a food-grade photoinitiator DDFD, so the biomedical material prepared by the bioinitiator has good biocompatibility and will not cause side effects such as cytotoxic reactions in the human body.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The gel of the present invention has multiple characteristics including simple preparation, body temperature triggering, high mechanical strength and biocompatibility:

[0026] 1) The gel in the present invention is prepared based on bulk polymerization of photocuring, and the composition and preparation method are simple; the precursor composition can be mixed evenly within a few seconds, and the photocuring cross-linking can be completed within a few seconds of light exposure, and the complex structure can be customized according to needs. The deformation recovery of the gel can be triggered at a temperature of 38°C, and it can be used on the human body, and the deformation recovery can be completed within ten seconds, with a fast recovery speed.

[0027] 2) The present invention uses a food-grade photoinitiator DDFD, and the gel prepared therefrom has good biocompatibility and will not cause side effects such as cytotoxic reactions in the human body.

[0028] 3) The shape memory organic gel in the present invention has no metal artifacts under CT imaging. Description of the Drawings

[0029] Figure 1 is the flowchart of gel preparation in Example 1.

[0030] Figure 2 is the schematic diagram of the shape memory process in Example 1.

[0031] Figure 3 is the physical diagram of the shape memory process in Example 1. Detailed Description of the Invention

[0032] The following embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Therefore, the detailed descriptions of the embodiments of the present invention provided below are not intended to limit the scope of the claimed invention, but merely represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0033] In the present invention, unless otherwise specified, all devices, raw materials, etc. can be purchased from the market or are commonly used in the industry. The methods in the following embodiments are conventional methods in the art unless otherwise specified.

[0034] Example 1:

[0035] The present invention provides a shape memory gel, and the preparation process is as Figure 1 shown, including the following steps:

[0036] (1) Weigh 1 g of dihydro-4,4-dimethyl-2,3-furandione (DDFD), 50 g of polyurethane acrylate (TAPUA), 24 g of isooctyl acrylate (2-EHA), and 25 g of 4-acryloylmorpholine (ACMO);

[0037] (2) Mix the components in step (1), and magnetically stir for several minutes to obtain a precursor solution;

[0038] (3) Irradiate the precursor solution with a UV lamp with a wavelength of 405 nm and a power of 50 W at a distance of 2 cm, and crosslink and cure after 5 s.

[0039] During the preparation process of this embodiment, under ultraviolet light irradiation, the -C- bonds in the monomer are bonded to the -C- bonds in the crosslinking agent to form a polymer chain organic gel network through a photoinitiator. The shape memory process of this gel is as follows Figure 2 shown: Taking the permanent state in the shape of a cuboid as an example, under the action of an external force, it is compressed into a temporary state; this temporary state can be restored to the permanent state at the thermally triggered temperature (38 °C).

[0040] The physical diagram of the shape memory process of the gel prepared in this embodiment can be seen in Figure 3 : The gel sample prepared in this embodiment is formed into a curly sheet (0 s) under the action of an external force, and this shape remains unchanged without external stimulation. The sample is placed in a liquid environment at 38 °C (water in this embodiment), and it returns to its original unfolded state from the curly state after 5 s.

[0041] The tensile modulus of the gel sample prepared in this embodiment is 500 MPa, and it has good mechanical properties.

[0042] The above are only the preferred embodiments of the present invention. It should be pointed out that: for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A gel precursor composition based on photocuring crosslinking, characterized in that, The invention is composed of the following components in parts by weight: 15-35 parts of isooctyl acrylate, 25-40 parts of 4-acryloylmorpholine, 0.5-1 part of a photoinitiator, 30-50 parts of a crosslinking agent and a solvent; the crosslinking agent is polyurethane acrylate; the solvent is water; the mass fraction of the solvent in the gel precursor composition is ≤20%.

2. The gel precursor composition according to claim 1, wherein The photoinitiator is dihydro-4,4-dimethyl-2,3-furandione.

3. The gel prepared from the gel precursor composition according to any one of claims 1-2, characterized in that, The preparation of the gel includes the following steps: The components are mixed and stirred thoroughly to obtain a gel precursor solution; The gel is obtained by cross-linking and curing the gel precursor solution under ultraviolet light.

4. The gel according to claim 3, wherein The wavelength of the ultraviolet light is 365-405 nm.

5. The gel according to claim 3, characterized in that, The cross-linking curing time is 2 to 5 s.

6. Use of the gel according to claim 3 in preparing shape memory materials.

7. The application according to claim 6, characterized in that, Application in the preparation of biomedical materials.

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