Vegetable oil-based self-repairing photo-thermal response shape memory polymer as well as preparation method and application thereof

Abstract

The invention relates to a vegetable oil-based self-repairing photo-thermal response shape memory polymer and a preparation method and application thereof, the preparation method comprises the following steps: 1, reacting oleic acid, formic acid and hydrogen peroxide, and taking p-toluenesulfonic acid as a catalyst to obtain an intermediate product A; 2, reacting the prepared intermediate product A with hexamethylene diisocyanate and p-benzoquinone dioxime to obtain an intermediate product B; and 3, adding epoxy resin and an epoxy resin accelerator, and heating and curing to obtain the vegetable oil-based self-repairing photo-thermal response shape memory polymer. Oxime-carbamate dynamic bonds and ester exchange dynamic bonds in the vegetable oil-based self-repairing photo-thermal response shape memory polymer prepared by the invention can endow the prepared polymer with excellent self-repairing capability and shape memory performance, the polymer is prepared from a bio-based material, the process is simple and convenient, the mechanical property is controllable, and the shape memory effect is good. The self-repairing and shape memory functions can be achieved under the ultraviolet excitation heating condition, and the shape memory performance and mechanical performance loss is small after repeated use.

Description

Technical Field

[0001] The present invention belongs to the field of bio-based smart polymer materials, and specifically relates to a plant oil-based self-repairable photothermal responsive shape memory polymer and a preparation method and application thereof. Background Art

[0002] Shape memory materials, as a type of smart material that can restore its original shape in response to specific external stimuli (such as heat, light, electricity, etc.), have attracted much attention since their advent. In particular, shape memory polymers and their composites have been developing rapidly since they were discovered in the 1980s. When these materials encounter external conditions such as heat, electricity, magnetic fields, moisture, chemical stimulation, microwaves or light, they can temporarily change their shape and restore after the stimulation is eliminated. Thermal activation is the most common method. Compared with shape memory alloys, shape memory polymers have excellent processability, morphological plasticity, repairability, biodegradability and adjustable glass transition temperature (Tg), and they occupy a pivotal position in the research of smart materials. It is particularly worth mentioning that light-responsive shape memory polymers and their composites have become the preferred objects in the field of materials science due to their unique properties. As a stimulus source, light is not only energy-rich and easy to control, but can also be transmitted remotely without a medium, accurately positioned, and is safe and harmless to human tissue. It can be flexibly distributed through optical fibers. These characteristics have greatly broadened the application scope of shape memory polymers, especially in biomedicine, microdevices, space exploration, and large-scale engineering.

[0003] However, the main raw materials of shape memory polymers are mostly derived from petrochemical resources, which are not only expensive and non-biodegradable, but also produce a lot of greenhouse gases and consume huge amounts of energy during the production process. Therefore, using biomass resources to replace traditional petrochemical resources has become an inevitable trend of the times. As an important part of biomass resources, vegetable oils and fats are rich in unsaturated fatty acids, rich in resources, low in price, and environmentally friendly, and have great potential as energy and chemical raw materials. Among them, oleic acid has become a research hotspot for chemical modification because of its widespread existence and low cost.

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

[0005] 1,4-Benzoquinone dioxime (BQDO) is a novel and photoresponsive compound. Its dark conjugated structure gives it good photothermal response performance. At the same time, BQDO can react with isocyanate to generate dynamic oxime-carbamate bonds, which brings excellent reprocessability and shape memory effect to the polymer. In addition, BQDO has two hydroxyl groups and a rigid six-membered ring structure, which enables it to effectively adjust the cross-linking density of the polymer and the rigid-flexible balance of the network structure.

[0006] The introduction of oxime-carbamate groups into polymers can not only give the materials photostrictive or bending properties, but also maintain their excellent thermal stability and film-forming properties, opening up new ways to design smart materials that can precisely respond to external stimuli. The versatility and controllability of oxime-carbamate groups make them key components for building advanced photoresponsive polymers. The introduction of dynamic covalent bonds gives the material the ability to reversibly crosslink and exchange, thereby achieving the dual characteristics of self-healing and shape memory. These unique properties not only extend the service life of the material and reduce maintenance costs, but also expand its application areas, which is of great significance for promoting efficient resource utilization and sustainable development. Through sophisticated structural design, the photoresponsive groups are integrated into the material, which can give it the characteristics of dual photothermal response, providing innovative ideas and methods for the functional application of bio-based resources, indicating that it will show broad application prospects in the fields of intelligent control systems, medical equipment and electronic materials. Summary of the invention

[0007] Technical problem to be solved: The present invention provides a plant oil-based self-repairable photothermal responsive shape memory polymer and its preparation method and application. A shape memory polymer integrating dynamic oxime-carbamate bonds and dynamic ester exchange is prepared using oleic acid as raw material.

[0008] Technical solution: A method for preparing a vegetable oil-based self-healing photothermal responsive shape memory polymer. In the first step, oleic acid and formic acid are added to a reaction vessel in a molar ratio of 1:(1.25-1.6), p-toluenesulfonic acid is added in an amount of 0.8%-1.2% of the total mass of the system, and hydrogen peroxide is added dropwise at 65°C. The molar ratio of hydrogen peroxide to oleic acid is 5:1. The reaction is performed for 5 hours, cooled to room temperature, and washed thoroughly with ethyl acetate to obtain an intermediate product A. In the second step, the intermediate product A and hexamethylene diisocyanate are added in a molar ratio of 1:(1.1-1.4 ) and p-benzoquinone dioxime are added to the reaction vessel, the amount of p-benzoquinone dioxime added accounts for 5% to 20% of the total reaction system mass, 0.5% to 0.8% of the total mass of the system is added with an organic tin catalyst, and the reaction is carried out at 35°C for 1 hour to obtain an intermediate product B; the third step is to mix the intermediate product B with an epoxy resin and an epoxy resin accelerator accounting for 0.5% to 0.8% of the total mass of the system, the molar ratio of the intermediate product B to the epoxy resin is 1: (1 to 1.5), and the mixture is cured at 125°C for 2 hours to obtain a self-healing photothermal responsive shape memory polymer.

[0009] Preferably, the organotin 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, in the third step, the molar ratio of the intermediate product B to the epoxy resin is 1:1.

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

[0013] The vegetable oil-based self-repairing photothermal responsive shape memory polymer prepared by the above preparation method.

[0014] Application of the above polymer in the preparation of plant oil-based self-healing photothermal responsive shape memory products.

[0015] Beneficial effects: (1) The reversible dynamic oxime-carbamate bond and dynamic ester bond introduced in the present invention can not only improve the photothermal response shape memory ability of the polymer material, but also make the material have certain self-healing properties. (2) The preparation process of the present invention is simple, the raw materials are easy to obtain, the product has stable performance and has certain application value. (3) The rigid-flexible properties can be adjusted by adjusting the hexamethylene diisocyanate to be added in the second step and the ratio of quinone dioxime to epoxy resin in the third step of curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The initial state of the polymer spline and the bending morphology under UV light irradiation.

[0017] Figure 2 The specimens were restored to their original shape at 60°C.

[0018] Figure 3 Illustration of material fragments and restoration effects.

[0019] Figure 4 The polymer solidifies into a curved M-shaped initial state in the mold, cools to an intermediate shape at room temperature, and recovers to the initial shape within 60°C.

[0020] Figure 5 The infrared spectra of oleic acid, intermediate products A and B in Examples 1-5 are shown.

[0021] In the infrared spectrum, we can see that at 2854cm -1 and 2922cm -1 Strong absorption peaks appeared near 3330cm -1 The obvious absorption peak at 1726cm corresponds to the OH vibration bond of the hydroxyl group in the compound, and the characteristic peak of intermediate B is more obvious. This indicates the successful synthesis of intermediate A. -1 The characteristic peak of the free carbon group C=O is at 1536cm, indicating that -NCO reacts with -OH to generate a new -NHCOO-. -1 The characteristic peak at , which is the carbonyl peak formed after the reaction of benzoquinone dioxime and isocyanate. The appearance of the above characteristic peaks indicates the successful synthesis of intermediate B. DETAILED DESCRIPTION

[0022] The parts not mentioned in the text are the same as the prior art or can be implemented by the prior art. The following are the preferred embodiments of the present invention, but the present invention is not limited to the following embodiments only, and slight improvements on the embodiments will also be regarded as the protection scope of the present invention.

[0023] Example 1

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

[0025] Example 2

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

[0027] Example 3

[0028] The first step: according to the following molar ratio, oleic acid and formic acid are added to the reaction container at a molar ratio of 1:1.5, 0.5% of the total mass of the system is added to p-toluenesulfonic acid, and a hydrogen peroxide solution (the molar amount is 500% of the oleic acid) is added dropwise at 65°C, and the reaction is continued for 5 hours, cooled to room temperature, and thoroughly washed with ethyl acetate to obtain an intermediate product A; the second step: according to the following molar ratio, the intermediate product A and hexamethylene diisocyanate are added to the reaction container at a molar ratio of 1:1.4, and 0.5% of the total mass of the system is added. % of dibutyltin dilaurate, react at 35°C for 1h to obtain intermediate product B; the third step: mix the intermediate product B with p-benzoquinone dioxime (the molar amount is 10% of the molar amount of intermediate product B), E44 epoxy resin (the molar amount is 100% of the molar amount of intermediate product B) and epoxy accelerator 2,4,6-tris(dimethylaminomethyl)phenol (the mass is 0.5% of the total mass of the system), and cure it under heating conditions at 125°C for 2 hours to obtain a vegetable oil-based self-healing photothermal responsive shape memory polymer.

[0029] Example 4

[0030] The first step: according to the following molar ratio, oleic acid and formic acid are added to the reaction container at a molar ratio of 1:1.5, p-toluenesulfonic acid is added at a total mass of 0.5%, hydrogen peroxide solution (molar amount is 500% of oleic acid) is added dropwise at 65°C, the reaction is continued for 5 hours, 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 to the reaction container at a molar ratio of 1:1.25, and 0. 5% dibutyltin dilaurate is reacted at 35°C for 1h to obtain an intermediate product B; the third step: the intermediate product B is mixed with p-benzoquinone dioxime (the molar amount is 5% of the molar amount of the intermediate product B), E44 epoxy resin (the molar amount is 100% of the molar amount of the intermediate product B) and epoxy accelerator 2,4,6-tris(dimethylaminomethyl)phenol (the mass is 0.5% of the total mass of the system), and cured at 125°C for 2 hours to obtain a vegetable oil-based self-healing photothermal responsive shape memory polymer.

[0031] Example 5

[0032] The first step: according to the following molar ratio, oleic acid and formic acid are added to the reaction container at a molar ratio of 1:1.5, p-toluenesulfonic acid is added at a total mass of 0.5%, hydrogen peroxide solution (molar amount is 500% of oleic acid) is added dropwise at 65°C, the reaction is continued for 5 hours, 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 to the reaction container at a molar ratio of 1:1.25, and 0. 5% dibutyltin dilaurate, react at 35°C for 1h to obtain intermediate product B; step three: mix intermediate product B with p-benzoquinone dioxime (the molar amount is 20% of the molar amount of intermediate product B), E44 epoxy resin (the molar amount is 100% of the molar amount of intermediate product B) and epoxy accelerator 2,4,6-tris(dimethylaminomethyl)phenol (the mixed mass is 0.5% of the total mass of the system), and cure at 125°C for 2 hours to obtain a vegetable oil-based self-healing photothermal responsive shape memory polymer.

[0033] Table 1 Performance comparison of each embodiment group

[0034] project 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 was subjected to a photothermal response shape memory performance test: the initial polymer strip (such as Figure 1 ), the specimen was bent and deformed under ultraviolet light; the specimen was reheated at 60℃ and quickly recovered to its original shape within 5s. Figure 2 .

[0036] The polymer material of Example 2 was tested for self-healing performance: the initial fragment material (such as Figure 3 ), after hot pressing at 160℃ for 10min, the dynamic bonds in the fragmented materials were reconnected to achieve complete restoration.

[0037] The polymer material of Example 2 was tested for shape memory performance: the initial material was solidified into an M-shaped curved pattern in a mold as an initial state, such as Figure 4 , reshaped at 60°C to unfold the bent M-shape, and cooled to room temperature to fix it into an intermediate shape. It was then heated at 60°C again to restore its original shape within 10 seconds.

Claims

1. A method for preparing a vegetable oil-based self-repairing photothermal responsive shape memory polymer, characterized in that: In the first step, oleic acid and formic acid are added to a reaction vessel at a molar ratio of 1: (1.25-1.6), p-toluenesulfonic acid is added at a total mass of 0.8%-1.2%, hydrogen peroxide is added dropwise at 65°C, the molar ratio of hydrogen peroxide to oleic acid is 5:1, the reaction is performed for 5 hours, the mixture is cooled to room temperature and thoroughly washed with ethyl acetate to obtain an intermediate product A; in the second step, the intermediate product A and hexamethylene diisocyanate are added to the reaction vessel at a molar ratio of 1: (1.1-1.4) and p-benzoquinone dioxime. , the amount of benzoquinone dioxime added accounts for 5% to 20% of the total reaction system mass, 0.5% to 0.8% of the total mass of the system is added with an organic tin catalyst, and the reaction is carried out at 35°C for 1 hour to obtain an intermediate product B; the third step is to mix the intermediate product B with an epoxy resin and an epoxy resin accelerator accounting for 0.5% to 0.8% of the total mass of the system, the molar ratio of the intermediate product B to the epoxy resin is 1: (1 to 1.5), and the mixture is cured at 125°C for 2 hours to obtain a self-healing photothermal responsive shape memory polymer.

2. The method for preparing the vegetable oil-based self-repairing photothermal responsive shape memory polymer according to claim 1, characterized in that: The organotin catalyst in the second step is dibutyltin dilaurate or dibutyltin diacetate.

3. The method for preparing the vegetable 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 method for preparing the vegetable oil-based self-repairing photothermal responsive shape memory polymer according to claim 1, characterized in that: In the third step, the molar ratio of the intermediate product B to the epoxy resin is 1:

1.

5. The method for preparing the vegetable 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 vegetable oil-based self-repairing photothermal responsive shape memory polymer prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the polymer according to claim 6 in the preparation of a vegetable oil-based self-repairing photothermal responsive shape memory product.

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