Multi-stimulus-response shape memory polymer material and preparation method thereof
Through a photopolymerization system of flexible monomers, hard monomers, β-dione ligand monomers, free ligands, photoinitiators and metal salts, a shape memory polymer material with multiple stimulation response is constructed, and the shape memory under multiple stimulation is achieved using coordination bonds, which solves the problem of single stimulation response in the prior art and achieves efficient multi-stimulation shape memory effect.
Patent Information
- Application Number
- CN202510481911.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-17
- Publication Date
- 2025-07-18
AI Technical Summary
The existing shape memory polymer materials mainly deform to a single stimulus, lack response to multiple stimulus factors, making it difficult to achieve the shape memory effect under multiple stimuli.
A photopolymerization system with flexible monomers, hard monomers, β-dione ligand monomers, free ligands, photoinitiators and metal salts is used to form a shape memory polymer material with multiple stimulation response through ultraviolet light. A dynamic coordination crosslinking network is constructed using coordination bonds formed by metal ions and ligands on the polymer chain and free ligands to achieve shape memory under multiple stimulation.
The shape memory function is realized under temperature, pH and humidity stimulation, and the shape fixation rate and retention rate reach more than 95%. The preparation process is simple and the cost is low, and it is suitable for industrial production.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the field of novel functional materials, and particularly relates to a multi-stimulus responsive shape memory polymer material and a preparation method thereof. Background Art
[0002] Shape memory polymer materials are a type of novel functional materials that can return to their original shape under external stimuli, such as thermal stimuli. Since the discovery of shape memory polymer materials in the 1980s, related research has developed vigorously. A variety of different shape memory polymer materials have been developed and applied in fields such as food processing and biomedicine.
[0003] The most common shape memory polymers adopt a two-phase design strategy (Prog. Polym. Sci. 2015, 49 - 50: 79). Among them, the cross-linked structure is used for morphological fixation, and the glass transition temperature or the crystalline melting transition temperature is used to generate the deformed morphology. When the temperature rises above the transition temperature, the shape memory polymer material becomes an elastic material. At this time, it can be deformed by stretching or other deformation methods to generate the required deformation and obtain the deformed morphology. Then it is cooled below the transition temperature to fix the deformed morphology. When the temperature rises above the transition temperature again, the material can return to its original morphology.
[0004] In recent years, dynamic bonds have become an important means for constructing shape memory polymers, and the key lies in constructing appropriate dynamic exchange bonds in the polymer network. Currently, the most common method is to construct shape memory polymer materials through dynamic covalent exchange reactions. These dynamic exchange reactions include transesterification reactions, urethane bond exchange reactions, DA reactions, disulfide bond exchange reactions, diselenide bond exchange reactions, reversible TAD reactions, etc. (ACS Appl. Mater. Interfaces 2020, 12, 8, 9833; Polym. Chem., 2020, 11, 1410). The dynamic bonds that can produce dynamic exchange reactions are mainly used to construct thermally adaptable shape memory polymer materials. In addition to thermal stimuli, magnetic fields, electricity, light, humidity, pH, etc. can also be used to produce the shape memory effect. However, current shape memory polymer materials mainly deform in response to a single stimulus and lack responsiveness to multiple stimulus factors. Therefore, seeking a new construction strategy for multi-stimulus responsive shape memory polymer materials is an urgent problem to be solved. Summary of the Invention
[0005] Aiming at the deficiencies of the above-mentioned prior art, the present invention provides a multi-stimulus responsive shape memory polymer material and a preparation method thereof.
[0006] The present invention provides a multi-stimulus responsive shape memory polymer material, which is composed of a photopolymerization system including 30-70 parts by mass of a flexible monomer, 20-40 parts by mass of a rigid monomer, 3-20 parts by mass of a monomer containing a β-diketone ligand, 6-20 parts by mass of a free ligand, 0.1-2 parts by mass of a photoinitiator, and 5-15 parts by mass of a metal salt, and is obtained by ultraviolet light-induced polymerization.
[0007] Preferably, the flexible monomer is selected from one or more of ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-(2-methoxyethoxy)ethyl methacrylate, ethyl 2-[[(butylamino)carbonyl]oxy]acrylate, and isooctyl acrylate.
[0008] Preferably, the rigid monomer is selected from one or more of acrylic acid, methacrylic acid, methyl methacrylate, 4-acryloylmorphine, and N,N-dimethylacrylamide.
[0009] Preferably, the monomer containing a β-diketone ligand is selected from one of ethylene glycol methylacetoacetate methacrylate, 3-[(4-vinylphenyl)methyl]-2,4-pentanedione, and 2-allyl-1,3-diphenyl-1,3-propanedione.
[0010] Preferably, the free ligand is selected from one of imidazole, pyridine, o-phenanthroline, 2-phenylimidazole, 4,5-dicyanoimidazole, 4-methylpyridine, 2,6-dimethylpyridine, 5-methyl-1,10-phenanthroline, and 5,6-dimethyl-1,10-phenanthroline.
[0011] Preferably, the photoinitiator is selected from one of ethyl 2,4,6-trimethylbenzoylphosphinate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-isopropylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, benzoin dimethyl ether, and methyl o-benzoylbenzoate.
[0012] Preferably, the metal salt is one or more of copper nitrate, nickel nitrate, europium nitrate, dysprosium nitrate, iron nitrate, gallium nitrate, samarium nitrate, zinc perchlorate, europium perchlorate, and copper perchlorate.
[0013] The present invention also provides a preparation method of a multi-stimulus responsive shape memory polymer material, including the following steps:
[0014] S1: Mix the flexible monomer, rigid monomer, monomer containing β-diketone ligand, free ligand, and photoinitiator evenly by stirring, then add the metal salt and stir. After centrifugal degassing, pour the mixture into a mold and react under ultraviolet light irradiation at room temperature for 5 - 20 min to form a sheet with a thickness of 1 - 2 mm.
[0015] S2: Cut the sheet obtained in step S1 into rectangular splines, heat it to a transition temperature of 50 - 100 °C or above, or increase the relative humidity to 80% or above, or lower the pH to below 3. Apply stress along the longitudinal direction to make the strain reach 100% - 500%. Then cool it to room temperature, or reduce the relative humidity to below 50%, or increase the pH to above 7.5. Remove the external force to obtain the material.
[0016] Preferably, the temperature, pH, and humidity can all trigger the shape memory material to return to its original shape.
[0017] The working principle of the multiple stimulus-responsive shape memory involved in the present invention is as follows:
[0018] The multiple stimulus-responsive shape memory polymer material forms a dynamic coordination crosslinking network through the coordination bonds formed by metal ions binding to the ligands on the polymer chain and free ligands. The coordination bonds can be weakened when the temperature rises, the humidity increases, and the pH decreases. Therefore, when the temperature rises, the humidity increases, and the pH decreases, the shape memory polymer material transforms into a material with stronger elasticity. In this state, deform the shape memory polymer material to the required degree. Cool the deformed shape memory polymer material to room temperature, or reduce the relative humidity to below 50%, or increase the pH to above 7.5. At this time, the coordination bond complexation strength increases, the polymer network becomes stronger, and the shape is thus fixed. When the temperature and humidity are increased again and the pH is decreased, it can return to the original shape.
[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0020] (1) The shape memory polymer material prepared by the present invention can achieve the shape memory function under the stimulation of temperature, pH, and humidity. The shape fixation rate and shape retention rate under the three different stimulation factors can both reach over 95%.
[0021] (2) The transition temperature, transition relative humidity, and transition pH value of the shape memory polymer material prepared by the present invention can be adjusted within a wide range. On the basis of facilitating the molding and manufacturing of the polymer material, it meets the requirements of various application scenarios.
[0022] (3) The preparation process adopted by the present invention is simple, with low cost, easy to control, and low energy consumption, and is suitable for large-scale industrial production. Detailed implementation mode
[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0024] Example 1
[0025] S1: Mix 60 parts by mass of 2-(2-methoxyethoxy)ethyl methacrylate, 20 parts by mass of methyl methacrylate, 5 parts by mass of ethylene glycol bis(acetoacetate) methacrylate, 5 parts by mass of o-phenanthroline, and 0.5 part by mass of ethyl 2,4,6-trimethylbenzoylphosphinate evenly, then add 8 parts by mass of gallium nitrate. After centrifugal degassing, pour it into a mold and react under 365 nm ultraviolet light irradiation at room temperature for 15 min to form a 2-mm-thick sheet.
[0026] S2: Cut the sheet obtained in step S1 into rectangular splines, heat it to a temperature above the transition temperature (90 °C), or increase the relative humidity to above 80%, or lower the pH to below 3. Apply stress along the longitudinal direction to make the strain reach 500%. Then cool it to room temperature, or reduce the relative humidity to below 50%, or increase the pH to above 7.5. Remove the external force to obtain the material.
[0027] Example 2
[0028] S1: Mix 70 parts by mass of 2-(2-methoxyethoxy)ethyl methacrylate, 30 parts by mass of 4-acryloylmorphine, 6 parts by mass of 3-[(4-vinylphenyl)methyl]-2,4-pentanedione, 5 parts by mass of pyridine, and 0.6 part by mass of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide evenly, then add 9 parts by mass of nickel nitrate. After centrifugal degassing, pour it into a mold and react under 365 nm ultraviolet light irradiation at room temperature for 16 min to form a 2-mm-thick sheet.
[0029] S2: Cut the sheet obtained in step S1 into rectangular splines, heat it to a temperature above the transition temperature (85 °C), or increase the relative humidity to above 80%, or lower the pH to below 2.5. Apply stress along the longitudinal direction to make the strain reach 500%. Then cool it to room temperature, or reduce the relative humidity to below 50%, or increase the pH to above 7.5. Remove the external force to obtain the material.
[0030] Example 3
[0031] S1: Mix 70 parts by mass of ethyl 2-[[(butylamino)carbonyl]oxy]acrylate, 35 parts by mass of acrylic acid, 7 parts by mass of 2-allyl-1,3-diphenyl-1,3-propanedione, 5 parts by mass of 2,6-dimethylpyridine, and 0.6 parts by mass of 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one uniformly, add 9 parts by mass of samarium nitrate after mixing and stirring, degas by centrifugation, then pour into a mold and react under 365 nm ultraviolet light irradiation at room temperature for 15 min to form a 2-mm thick sheet.
[0032] S2: Cut the sheet obtained in step S1 into rectangular splines, heat to above the transition temperature (95 °C), or increase the relative humidity to above 75%, or lower the pH to below 3, apply stress along the longitudinal direction to make the strain reach 500%, cool to room temperature, or lower the relative humidity to below 50%, or raise the pH to above 7.5, then remove the external force to obtain the material.
[0033] Comparative Example 1
[0034] S1: Mix 60 parts by mass of 2-(2-methoxyethoxy)ethyl methacrylate, 30 parts by mass of methyl methacrylate, 1.5 parts by mass of ethylene glycol dimethacrylate, and 0.5 parts by mass of ethyl 2,4,6-trimethylbenzoylphosphinate uniformly, degas by centrifugation, then pour into a mold and react under 365 nm ultraviolet light irradiation at room temperature for 12 min to form a 2-mm thick sheet.
[0035] S2: Cut the sheet obtained in step S1 into rectangular splines, heat to above the transition temperature (80 °C), apply stress along the longitudinal direction to make the strain reach 500%, cool to room temperature, then remove the external force to obtain the material.
[0036] Comparative Example 2
[0037] S1: Mix 60 parts by mass of 2-(2-methoxyethoxy)ethyl methacrylate, 30 parts by mass of 4-acrylylmorphine, 1.5 parts by mass of ethylene glycol dimethacrylate, and 0.6 parts by mass of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide uniformly, degas by centrifugation, then pour into a mold and react under 365 nm ultraviolet light irradiation at room temperature for 12 min to form a 2-mm thick sheet.
[0038] S2: Cut the sheet obtained in step S1 into rectangular splines, heat to above the transition temperature (90 °C), apply stress along the longitudinal direction to make the strain reach 500%, cool to room temperature, then remove the external force to obtain the material.
[0039] Comparative Example 3
[0040] S1: Mix 60 parts by mass of ethyl 2-[[(butylamino)carbonyl]oxy]acrylate, 35 parts by mass of acrylic acid, 1.5 parts by mass of ethylene glycol dimethacrylate, and 0.6 part by mass of 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one uniformly by stirring. After centrifugal degassing, pour the mixture into a mold and react it under ultraviolet light irradiation at 365 nm at room temperature for 13 min to form a 2-mm thick sheet.
[0041] S2: Cut the sheet obtained in step S1 into rectangular splines, heat it to a temperature above the transition temperature (95 °C), apply a stress along the longitudinal direction to make the strain reach 500%, cool it to room temperature, and remove the external force to obtain the material.
[0042] Table 1 Performance comparison between shape memory polymer materials without coordination bonds and the shape memory polymer materials prepared in the present invention
[0043]
[0044]
[0045] It can be seen from the data comparison in Table 1 that the temperature-stimulated shape fixation rate, temperature-stimulated shape retention rate %, humidity-stimulated shape fixation rate %, humidity-stimulated shape retention rate %, pH-stimulated shape fixation rate %, and pH-stimulated shape retention rate % of each example and comparative example indicate that the materials of the present invention have obvious advantages in shape memory induced by multiple stimuli. The comparative example without coordination crosslinking only has shape memory performance under temperature stimulation. In addition to the shape memory function with multiple stimulus responses, the materials of the present invention also exhibit excellent shape fixation rate and shape retention rate, which are generally slightly higher than those of the comparative example without coordination bonds.
[0046] In the description of the specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0047] The above content is only an example and illustration of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.
Claims
1. A multi-stimulus responsive shape memory polymer material, characterized in that, It is composed of a photopolymerization system including 30 - 70 parts by mass of a flexible monomer, 20 - 40 parts by mass of a hard monomer, 3 - 20 parts by mass of a monomer containing a β-diketone ligand, 6 - 20 parts by mass of a free ligand, 0.1 - 2 parts by mass of a photoinitiator, and 5 - 15 parts by mass of a metal salt, and is obtained by ultraviolet light-initiated polymerization.
2. The shape memory polymer material with multiple stimulus responses according to claim 1, characterized in that, The flexible monomer is selected from one or more of ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-(2-methoxyethoxy)ethyl methacrylate, ethyl 2-[[(butylamino)carbonyl]oxy]acrylate, and isooctyl acrylate.
3. The shape memory polymer material with multiple stimulus responses according to claim 1, characterized in that, The hard monomer is selected from one or more of acrylic acid, methacrylic acid, methyl methacrylate, 4-acryloylmorphine, and N,N-dimethylacrylamide.
4. The shape memory polymer material with multiple stimulus responses according to claim 1, wherein The monomer containing a β-diketone ligand is selected from one of ethylene glycol bis(acetoacetate) methacrylate, 3-[(4-vinylphenyl)methyl]-2,4-pentanedione, and 2-allyl-1,3-diphenyl-1,3-propanedione.
5. The shape memory polymer material with multiple stimulus responses according to claim 1, wherein The free ligand is selected from one of imidazole, pyridine, o-phenanthroline, 2-phenylimidazole, 4,5-dicyanoimidazole, 4-methylpyridine, 2,6-dimethylpyridine, 5-methyl-1,10-phenanthroline, and 5,6-dimethyl-1,10-phenanthroline.
6. The shape memory polymer material with multiple stimulus responses according to claim 1, characterized in that, The photoinitiator is selected from one of ethyl 2,4,6-trimethylbenzoylphosphinate, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-isopropylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, benzoin dimethyl ether, and methyl o-benzoylbenzoate.
7. The shape memory polymer material with multiple stimulus responses according to claim 1, characterized in that, The metal salt is one or more of copper nitrate, nickel nitrate, europium nitrate, dysprosium nitrate, iron nitrate, gallium nitrate, samarium nitrate, zinc perchlorate, europium perchlorate, and copper perchlorate.
8. A method for preparing a multi-stimulus responsive shape memory polymer material according to any one of claims 1-7, characterized in that, It includes the following steps: S1: Mix the flexible monomer, hard monomer, monomer containing a β-diketone ligand, free ligand, and photoinitiator and stir evenly, then add the metal salt and stir. After centrifugal degassing, pour it into a mold and react under ultraviolet light irradiation at room temperature for 5 - 20 min to form a sheet with a thickness of 1 - 2 mm. S2: Cut the sheet obtained in step S1 into rectangular splines, heat it to a transition temperature of 50 - 100 °C or higher, or increase the relative humidity to 80% or higher, or lower the pH to 3 or lower. Apply stress along the longitudinal direction to make the strain reach 100% - 500%, cool to room temperature, or reduce the relative humidity to 50% or lower, or raise the pH to 7.5 or higher, and then remove the external force to obtain the material.
9. A multi-stimulus responsive shape memory polymer material according to claim 8, wherein, The temperature, pH, and humidity can all trigger the shape memory material to return to its original shape.