Plant oil-based self-repairing photothermal response shape memory polymer, preparation method and application thereof

Abstract

The application discloses a vegetable oil-based self-repairing photo-thermal response shape memory polymer, a preparation method and application thereof, and relates to the technical field of shape memory polymers. In a first step, oleic acid, formic acid and hydrogen peroxide are reacted to obtain an intermediate product A by using p-toluenesulfonic acid as a catalyst; in a second step, the obtained intermediate product A is reacted with hexamethylene diisocyanate and p-benzoquinone dioxime to obtain an intermediate product B; and in a third step, epoxy resin and an epoxy resin accelerator are added and heated to be cured to obtain the vegetable oil-based self-repairing photo-thermal response shape memory polymer. The oxime-urethane dynamic bond and the ester exchange dynamic bond in the vegetable oil-based self-repairing photo-thermal response shape memory polymer prepared by the application can endow the prepared polymer with excellent self-repairing ability and shape memory performance. The polymer is prepared by using a bio-based material, the process is simple, the mechanical performance is controllable, the self-repairing and shape memory functions can be realized under the condition of ultraviolet light excitation and heating, and the shape memory performance and mechanical performance loss after repeated use is small.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of bio-based intelligent polymer materials, and particularly relates to a vegetable oil-based self-repairable photo-thermal response shape memory polymer as well as a preparation method and application thereof. BACKGROUND

[0002] Shape memory materials, as a kind of intelligent materials capable of restoring their original shape in response to specific external stimuli (such as heat, light, electricity, etc.), have been attracting attention since their inception. In particular, shape memory polymers and their composites have been rapidly developed since the 1980s. When exposed to external conditions such as heat, electricity, magnetic field, moisture, chemical stimulus, microwave or light, these materials can temporarily change their shape and recover after the stimulus is removed. Among them, the heat-activated method is the most common. Compared with shape memory alloys, shape memory polymers have excellent processability, shape plasticity, repairability, biodegradability, and adjustable glass transition temperature (Tg), and play a crucial role in the research of intelligent materials. Especially worth mentioning is that photo-responsive shape memory polymers and their composites have become the preferred object in the field of materials science due to their unique properties. Light as a stimulus source is not only abundant in energy and easy to control, but also can be transmitted remotely and precisely located without medium, and is safe for human tissues. It can be flexibly distributed through optical fibers, which greatly broadens the application scope of shape memory polymers, especially in the fields of biomedical, micro devices, space exploration and large-scale engineering.

[0003] However, the main raw materials of current shape memory polymers are mostly derived from petrochemical resources, which not only has high cost, but also is not biodegradable, and produces a large amount of greenhouse gases and consumes huge amounts of energy in the production process. Therefore, using biomass resources to replace traditional petrochemical resources has become an inevitable trend of the times. Vegetable oils, as an important part of biomass resources, are rich in unsaturated fatty acids, and have great potential as energy and chemical raw materials due to their abundant resources, low price and environmental friendliness. Among them, oleic acid has become a research hotspot due to its wide existence and low cost.

[0004] Self-repairable polymers, as another type of frontier material, have attracted widespread attention in the scientific and industrial communities in recent years due to their ability to self-repair damage, improve material durability and safety, and thus reduce resource consumption and environmental burden. This self-healing ability relies on the repair agent repairing the broken bonds within the polymer through intermolecular coupling or supramolecular forces. The fluidity and elasticity of the damaged site are key elements in triggering the healing mechanism.

[0005] 1,4-benzoquinone dioxime (BQDO) is a novel and photoresponsive compound, its dark conjugated structure endows it with good photothermal response performance; at the same time, BQDO can react with isocyanate to generate dynamic oxime-carbamate bond, which brings excellent reworkability and shape memory effect to the polymer. In addition, the two hydroxyl groups and the rigid six-membered ring structure of BQDO enable it to effectively adjust the crosslinking density and the rigid-flexible balance of the network structure of the polymer.

[0006] The introduction of oxime-carbamate groups into polymers not only endows the materials with photo-induced stretching or bending properties, but also maintains their excellent thermal stability and film-forming properties, opening up new ways for designing intelligent materials that can accurately respond to external stimuli. The multifunctionality and controllability of oxime-carbamate groups make them key components for constructing advanced photoresponsive polymers. The introduction of dynamic covalent bonds endows the materials with reversible crosslinking and exchange capabilities, thereby realizing the dual properties of self-repairing and shape memory. These unique properties not only extend the service life of the materials and reduce maintenance costs, but also expand their application fields, which is of great significance for promoting resource-efficient use and sustainable development. By ingenious structural design, the photoresponsive groups are integrated into the materials, which can endow them with photothermal dual response properties, providing innovative ideas and methods for the functionalization of bio-based resources. It is predicted that the materials will show broad application prospects in the fields of intelligent control systems, medical devices and electronic materials. SUMMARY

[0007] The technical problem solved by the present application is to provide a plant oil-based self-repairable photo-thermal response shape memory polymer, a preparation method and application thereof. The shape memory polymer fuses dynamic oxime-carbamate bonds and dynamic ester exchange and is prepared from oleic acid as a raw material.

[0008] Technical solution: The preparation method of the plant oil-based self-repairing photo-thermal response shape memory polymer, in the first step, add oleic acid and formic acid into the reaction container according to the molar ratio of 1:(1.25-1.6), add 0.8%-1.2% of p-toluenesulfonic acid to the total mass of the system, add hydrogen peroxide drop by drop at 65 DEG C, the molar ratio of hydrogen peroxide to oleic acid is 5:1, react for 5h, cool to room temperature and wash thoroughly with ethyl acetate to obtain intermediate product A; in the second step, add intermediate product A and hexamethylene diisocyanate into the reaction container according to the molar ratio of 1:(1.1-1.4) and p-benzoquinone dioxime, the amount of p-benzoquinone dioxime added accounts for 5%-20% of the total mass of the reaction system, add 0.5%-0.8% of organic tin catalyst to the total mass of the system, react for 1h at 35 DEG C to obtain intermediate product B; in the third step, mix intermediate product B with epoxy resin and 0.5%-0.8% of epoxy resin accelerator accounting for the total mass of the system, the molar ratio of intermediate product B to epoxy resin is 1:(1-1.5), and the self-repairing photo-thermal response shape memory polymer is prepared by heating at 125 DEG C for 2h.

[0009] Preferably, the organic tin catalyst in the second step is dibutyltin dilaurate or dibutyltin diacetate.

[0010] Preferably, the epoxy resin in the third step is E44 or E51.

[0011] Preferably, the molar ratio of intermediate product B to epoxy resin in the third step is 1:1.

[0012] Preferably, the epoxy resin accelerator in the third step is 2,4,6-tris(dimethylaminomethyl)phenol or triethanolamine.

[0013] The plant oil-based self-repairing photo-thermal response shape memory polymer prepared by the above preparation method.

[0014] The application of the above polymer in the preparation of plant oil-based self-repairing photo-thermal response shape memory products.

[0015] Beneficial effects: (1) The reversible dynamic oxime-carbamate bond and dynamic ester bond are introduced in the application, which not only improves the photo-thermal response shape memory ability of the polymer material, but also enables the material to have certain self-repairing performance. (2) The preparation process route of the application is simple, the raw materials are simple and easy to obtain, the prepared product has stable performance and has certain application value. (3) The rigidity and flexibility characteristics can be adjusted by adjusting the proportion of hexamethylene diisocyanate added in the second step and p-benzoquinone dioxime and epoxy resin in the curing process in the third step. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The initial state of the polymer sample and the bending shape under ultraviolet irradiation.

[0017] Figure 2 To restore the initial shape of the spline at 60°C.

[0018] Figure 3 To restore the initial shape of the spline at 60°C.

[0019] Figure 4 To restore the initial shape of the spline at 60°C.

[0020] Figure 5 To restore the initial shape of the spline at 60°C.

[0021] In the infrared spectrum, it can be seen that there are strong absorption peaks near 2854 cm -1 and 2922 cm -1 , indicating that the molecule contains a large number of methyl and methylene structures. In addition, for intermediate products A and B, there are obvious absorption peaks at 3330 cm -1 , corresponding to the O-H vibration bond of the hydroxyl group in the compound, and the characteristic peak of intermediate product B is more obvious. This indicates the successful synthesis of intermediate product A. 1726 cm -1 is the characteristic peak of the free carbon group C=O, indicating that -NCO and -OH react to form new -NHCOO-. In addition, there is a characteristic peak at 1536 cm -1 , which is the carbon group peak formed after the reaction of hydroquinone dioxime and isocyanate. The appearance of the above characteristic peaks indicates the successful synthesis of intermediate product B. DETAILED DESCRIPTION

[0022] The parts not involved in the text are the same as the prior art or can be realized by using the prior art. The following is a preferred embodiment of the present application, but the present application is not limited to only the following embodiments, and slight improvements on the embodiments will also be considered as the protection scope of the present application.

[0023] Example 1

[0024] The first step: according to the following molar ratio, oleic acid and formic acid are added into the reaction container according to the molar ratio 1:1.5, 0.5% of p-toluenesulfonic acid of the total mass of the system is added, hydrogen peroxide solution (molar amount is 500% of the molar amount of oleic acid) is added dropwise at 65°C, and the reaction is continued for 5h, cooled to room temperature, and washed thoroughly with ethyl acetate to obtain intermediate product A; the second step: according to the following molar ratio, intermediate product A and hexamethylene diisocyanate are added into the reaction container according to the molar ratio 1:1.1, 0.5% of dibutyltin dilaurate of the total mass of the system is added, and the reaction is carried out at 35°C for 1h to obtain intermediate product B; the third step: intermediate product B is mixed with p-benzoquinone dioxime (molar amount is 10% of the molar amount of intermediate product B), E44 epoxy resin (molar amount is 100% of the molar amount of intermediate product B) and epoxy promoter 2,4,6-tris(dimethylaminomethyl)phenol (mass is 0.5% of the total mass of the system), and cured at 125°C for 2h to obtain a vegetable oil-based self-repairing photo-thermal response shape memory polymer.

[0025] Example 2

[0026] The first step: according to the following molar ratio, oleic acid and formic acid are added into the reaction container according to the molar ratio 1:1.5, 0.5% of p-toluenesulfonic acid of the total mass of the system is added, hydrogen peroxide solution (molar amount is 500% of the molar amount of oleic acid) is added dropwise at 65°C, and the reaction is continued for 5h, cooled to room temperature, and washed thoroughly with ethyl acetate to obtain intermediate product A; the second step: according to the following molar ratio, intermediate product A and hexamethylene diisocyanate are added into the reaction container according to the molar ratio 1:1.25, 0.5% of dibutyltin dilaurate of the total mass of the system is added, and the reaction is carried out at 35°C for 1h to obtain intermediate product B; the third step: intermediate product B is mixed with p-benzoquinone dioxime (molar amount is 10% of the molar amount of intermediate product B), E44 epoxy resin (molar amount is 100% of the molar amount of intermediate product B) and epoxy promoter 2,4,6-tris(dimethylaminomethyl)phenol (mass is 0.5% of the total mass of the system), and cured at 125°C for 2h to obtain a vegetable oil-based self-repairing photo-thermal response shape memory polymer.

[0027] Example 3

[0028] The first step: according to the following molar ratio, oleic acid and formic acid are added into the reaction container according to the molar ratio 1:1.5, 0.5% of p-toluene sulfonic acid of the total mass of the system is added, hydrogen peroxide solution (molar amount is 500% of the molar amount of oleic acid) is added dropwise at 65°C, and the reaction is continued for 5h, cooled to room temperature, and washed thoroughly with ethyl acetate to obtain intermediate product A; the second step: according to the following molar ratio, intermediate product A and hexamethylene diisocyanate are added into the reaction container according to the molar ratio 1:1.4, 0.5% of dibutyltin dilaurate of the total mass of the system is added, and the reaction is carried out at 35°C for 1h to obtain intermediate product B; the third step: intermediate product B is mixed with p-benzoquinone dioxime (molar amount is 10% of the molar amount of intermediate product B), E44 epoxy resin (molar amount is 100% of the molar amount of intermediate product B) and epoxy promoter 2,4,6-tris(dimethylaminomethyl)phenol (mass is 0.5% of the total mass of the system), and cured at 125°C for 2h to obtain a vegetable oil-based self-repairing photo-thermal response shape memory polymer.

[0029] Example 4

[0030] The first step: according to the following molar ratio, oleic acid and formic acid are added into the reaction container according to the molar ratio 1:1.5, 0.5% of p-toluene sulfonic acid of the total mass of the system is added, hydrogen peroxide solution (molar amount is 500% of the molar amount of oleic acid) is added dropwise at 65°C, and the reaction is continued for 5h, cooled to room temperature, and washed thoroughly with ethyl acetate to obtain intermediate product A; the second step: according to the following molar ratio, intermediate product A and hexamethylene diisocyanate are added into the reaction container according to the molar ratio 1:1.25, 0.5% of dibutyltin dilaurate of the total mass of the system is added, and the reaction is carried out at 35°C for 1h to obtain intermediate product B; the third step: intermediate product B is mixed with p-benzoquinone dioxime (molar amount is 5% of the molar amount of intermediate product B), E44 epoxy resin (molar amount is 100% of the molar amount of intermediate product B) and epoxy promoter 2,4,6-tris(dimethylaminomethyl)phenol (mass is 0.5% of the total mass of the system), and cured at 125°C for 2h to obtain a vegetable oil-based self-repairing photo-thermal response shape memory polymer.

[0031] Example 5

[0032] The first step: according to the following molar ratio, oleic acid and formic acid are added into the reaction container according to the molar ratio 1:1.5, 0.5% of p-toluenesulfonic acid is added to the total mass of the system, hydrogen peroxide solution (molar mass is 500% of oleic acid) is added dropwise at 65°C, and the reaction is continued for 5h, cooled to room temperature, and washed thoroughly with ethyl acetate to obtain intermediate product A; the second step: according to the following molar ratio, intermediate product A and hexamethylene diisocyanate are added into the reaction container according to the molar ratio 1:1.25, 0.5% of dibutyltin dilaurate is added to the total mass of the system, and the reaction is carried out at 35°C for 1h to obtain intermediate product B; the third step: intermediate product B is mixed with p-benzoquinone dioxime (molar mass is 20% of the molar mass of intermediate product B), E44 epoxy resin (molar mass is 100% of the molar mass of intermediate product B) and epoxy promoter 2,4,6-tris(dimethylaminomethyl)phenol (mixed mass is 0.5% of the total mass of the system), and cured at 125°C for 2h to obtain a plant oil-based self-repairing photo-thermal response shape memory polymer.

[0033] Performance comparison of each example group in Table 1

[0034] Item Tensile strength (MPa) Elongation at break (%) Example 1 27.16±5.2 17.9±2.12 Example 2 15.64±5.15 118.85±3.5 Example 3 15.13±2.7 96.4±13.5 Example 4 3.6±2.8 151±24 Example 5 41.52±8.27 12.27±1.94

[0035] The polymer material of Example 2 is tested for photo-thermal response shape memory performance: the initial polymer sample (such as Figure 1 ) is irradiated by a UV lamp, and the sample is bent and deformed; the sample is reheated at 60°C, and the initial shape is restored within 5s, such as Figure 2 .

[0036] The polymer material of Example 2 is tested for self-repairing performance: the initial fragmented material (such as Figure 3 ) is hot-pressed at 160°C for 10min, and the dynamic bonds in the fragmented material are reconnected to achieve complete restoration.

[0037] The polymer material of Example 2 is tested for shape memory performance: the initial material is cured in a mold into an M-shaped bending pattern as the initial state, such as Figure 4 , the M-shaped bending is unfolded at 60°C, and the intermediate state shape is fixed by cooling to room temperature, and the initial shape is restored within 10s by reheating at 60°C.

Claims

1. A method for preparing a plant oil-based self-repairing photothermal response shape memory polymer, characterized in that, The first step is to add oleic acid and formic acid into the reaction container according to the molar ratio of 1:(1.25-1.6), and add 0.8%-1.2% of p-toluene sulfonic acid to the total mass of the system, then add hydrogen peroxide drop by drop at 65°C, the molar ratio of hydrogen peroxide to oleic acid is 5:1, the reaction is carried out for 5h, then the reaction is cooled to room temperature and washed with ethyl acetate, and the intermediate product A is obtained; the second step is to add the intermediate product A and hexamethylene diisocyanate into the reaction container according to the molar ratio of 1:(1.1-1.4) and p-benzoquinone dioxime, the amount of p-benzoquinone dioxime added is 5%-20% of the total mass of the reaction system, and 0.5%-0.8% of the total mass of the system is added to the organic tin catalyst, and the reaction is carried out at 35°C for 1h, and the intermediate product B is obtained; the third step is to mix the intermediate product B with epoxy resin and 0.5%-0.8% of the total mass of the system of epoxy resin accelerator, the molar ratio of the intermediate product B to epoxy resin is 1:(1-1.5), and the curing is carried out at 125°C for 2h, and the self-repairing photothermal response shape memory polymer is prepared.

2. The preparation method of the plant oil-based self-healing photothermal responsive shape memory polymer according to claim 1, characterized in that, The organic tin catalyst in the second step is dibutyltin dilaurate or dibutyltin diacetate.

3. The preparation method of the plant oil-based self-healing photothermal responsive shape memory polymer according to claim 1, characterized in that, The epoxy resin in the third step is E44 or E51.

4. The preparation method of the plant oil-based self-healing photothermal responsive shape memory polymer according to claim 1, characterized in that, The molar ratio of the intermediate product B to epoxy resin in the third step is 1:

1.

5. The preparation method of the plant oil-based self-healing photothermal responsive shape memory polymer according to claim 1, characterized in that, The epoxy resin accelerator in the third step is 2, 4, 6-tris(dimethylaminomethyl) phenol or triethanolamine.

6. The plant oil-based self-repairing photothermal response shape memory polymer prepared by the preparation method of any one of claims 1-5.

7. The use of the polymer of claim 6 in the preparation of plant oil-based self-repairing photothermal response shape memory products.

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