Reconfigurable eucommia rubber bidirectional shape memory material, preparation method and application thereof

Abstract

The application provides a reconfigurable eucommia rubber bidirectional shape memory material and a preparation method and application thereof, and comprises hydroxylated eucommia rubber and a boronic acid derivative crosslinking agent, wherein the amount of the boronic acid derivative crosslinking agent is 0.1%-10% of the mass of the hydroxylated eucommia rubber. The application introduces hydroxyl groups on the molecular chain of eucommia rubber through double bond oxidation and ring-opening reaction, and then crosslinks with a boronic acid derivative to obtain a reconfigurable eucommia rubber bidirectional shape memory material. The eucommia rubber shape memory material prepared by the application not only has excellent unidirectional shape memory function, but also has bidirectional shape memory function under external force. Meanwhile, the material also has self-repairing performance and permanent shape reconfiguration performance. The reconfigurable eucommia rubber bidirectional shape memory material has important application prospects in the fields of biological medicine and intelligent sensing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent material preparation, and particularly relates to a reconfigurable Eucommia ulmoides Oliver bidirectional shape memory material and a preparation method and application thereof. BACKGROUND

[0002] Shape memory material is a kind of responsive intelligent material capable of fixing a temporary shape and restoring an original permanent shape under external stimulation (such as heat, light, electricity, magnetism, water pressure, etc.). The structure of the shape memory material comprises a fixed phase and a recovery phase: the fixed phase (chemical cross-linking or physical cross-linking) is used to determine the permanent shape; and the recovery phase (including crystallization-melting, glass transition, hydrogen bond, ion bond, coordination bond or dynamic covalent bond dissociation-association, etc.) is used to realize the fixation and recovery of the temporary shape. The thermal responsive shape memory material is the most common and easiest to control shape memory material. Taking a semi-crystalline shape memory polymer as an example, the permanent shape of the material can be determined by chemical cross-linking. When the temperature is raised to above the melting point, the material changes into a soft amorphous state, and the shape of the material can be changed by applying stress; then when the temperature is lowered to the crystallization temperature, the material changes into a semi-crystalline state, and the crystallization can be used as a physical cross-linking point to fix the temporary shape. When the temperature is raised to the melting temperature again, the crystals melt, the physical cross-linking points disappear, and the material returns to the permanent shape under the driving of entropy elasticity.

[0003] Eucommia ulmoides Oliver is a kind of bio-based polymer material unique in China. The structure of Eucommia ulmoides Oliver is trans-polyisoprene, which is an isomer of natural rubber. Because of the high regularity of the molecular chain, Eucommia ulmoides Oliver is easy to crystallize at room temperature and is a typical semi-crystalline polymer, mainly existing in two crystal forms (α and β, with melting points of about 48 DEG C and about 52 DEG C, respectively). Therefore, Eucommia ulmoides Oliver can be used to prepare shape memory materials. Traditional Eucommia ulmoides Oliver shape memory materials usually need to use sulfur or DCP (dicumyl peroxide) for cross-linking, and the covalent bond cross-linking network formed is difficult to reconfigure topologically, resulting in that the permanent shape of the prepared shape memory material cannot be reconfigured. At the same time, the traditional Eucommia ulmoides Oliver shape memory material only has a single shape memory function, and once the temporary shape is recovered, the temporary shape needs to be edited again. These defects limit the wide application of Eucommia ulmoides Oliver shape memory materials. Therefore, it is of great significance to develop a bidirectional (reversible) shape memory material with a reconfigurable permanent shape. SUMMARY

[0004] The present application aims to provide a reconfigurable Eucommia ulmoides Oliver bidirectional shape memory material and a preparation method and application thereof, so as to solve the limitations of the prior art that the shape memory material cannot be reconfigured and only has a single shape memory.

[0005] To achieve the above object, the application provides a reconfigurable Eucommia ulmoides Oliver bidirectional shape memory material, which comprises hydroxylated Eucommia ulmoides Oliver and a boronic acid derivative crosslinking agent, wherein the amount of the boronic acid derivative crosslinking agent is 0.1%-10% of the mass of the hydroxylated Eucommia ulmoides Oliver. The three-dimensional network structure with dynamic borate ester bond crosslinking is prepared by introducing hydroxyl groups into the molecular chain of Eucommia ulmoides Oliver and reacting with the boronic acid derivative crosslinking agent. The material prepared by the application has bidirectional (reversible) shape memory function by virtue of the crystallization-melting of Eucommia ulmoides Oliver and the crystallization-induced elongation and melting-induced contraction of the molecular chain of Eucommia ulmoides Oliver under stress. The dynamic borate ester bond crosslinking network structure endows the material with reconfigurable characteristics and self-repairing performance.

[0006] Further, the hydroxylated Eucommia ulmoides Oliver is obtained by double bond oxidation and hydroxylation of Eucommia ulmoides Oliver, and the molar content of the hydroxyl groups in the hydroxylated Eucommia ulmoides Oliver is 0.1%-20%, preferably 1%-15%, and more preferably 2%-10% (the molar content of the hydroxyl groups represents the content of the oxidized double bonds in the original double bonds). By double bond oxidation and hydroxylation modification, on the one hand, the regularity can be adjusted, and thus the crystallization-melting state can be adjusted; on the other hand, the crosslinking between the molecular chains can be realized, and the material with mechanical strength can be obtained. According to the performance requirements of the target material, the amount of the crosslinking agent is adjusted, so as to control the crosslinking degree.

[0007] The double bond oxidation is carried out under the catalysis of peroxide and organic acid to realize the double bond epoxidation modification; and the hydroxylation is carried out under the action of metal halide catalyst and deionized water to form hydroxyl groups by ring opening of the epoxy groups.

[0008] A preparation method of a reconfigurable Eucommia ulmoides Oliver bidirectional shape memory material, comprising the following steps:

[0009] S1. Oxidizing the carbon-carbon double bonds in the molecular chain of Eucommia ulmoides Oliver by an oxidizing agent to obtain an oxidation intermediate;

[0010] S2. Converting the oxidation intermediate into hydroxylated Eucommia ulmoides Oliver under the action of metal halide and deionized water;

[0011] S3. Crosslinking and molding the hydroxylated Eucommia ulmoides Oliver under the action of a boronic acid derivative crosslinking agent to obtain the reconfigurable Eucommia ulmoides Oliver bidirectional shape memory material.

[0012] The reconfigurable Eucommia ulmoides Oliver shape memory material obtained by the method not only has excellent unidirectional shape memory function, but also has bidirectional (reversible) shape memory function under external force. Meanwhile, the material also has self-repairing performance and permanent shape reconfiguration performance.

[0013] Further, in step S1, the organic acid catalyst includes one or more of formic acid, acetic acid, propionic acid, butyric acid, benzoic acid; the molar ratio of the organic acid catalyst to the carbon-carbon double bond of the eucommia ulmoides gum is (0.01-0.20):1, and preferably the molar ratio is (0.01-0.10):1.

[0014] Further, in step S1, the oxidizing agent is a peroxide, including one or more of peroxobenzoic acid, hydrogen peroxide, peroxyacetic acid; the molar ratio of the oxidizing agent to the carbon-carbon double bond of the eucommia ulmoides gum is (0.01-0.20):1, and preferably the molar ratio is (0.01-0.10):1.

[0015] Further, in step S1, the solvent for the oxidation reaction is one or more of toluene, xylene, chlorobenzene, tetrahydrofuran, chloroform, n-hexane, petroleum ether; the reaction temperature is 0-80°C, and preferably 25-40°C; the reaction time is 1-24 hours, and preferably 1-8 hours; the mass concentration of the eucommia ulmoides gum in the solvent is 1%-10%, and preferably the concentration is 2-6%.

[0016] Further, in step S2, the metal halide includes one or more of ferric chloride, cupric chloride, ferrous chloride, cuprous chloride, silver chloride, palladium chloride, rhodium chloride, zirconium chloride, aluminum chloride, zinc chloride, copper bromide, ferric bromide, and cuprous bromide; the amount of the metal halide is 1%-10% of the mass of the oxidation intermediate product, and preferably the amount is 1-5%; the amount of the deionized water is 10%-200% of the mass of the eucommia ulmoides gum, and preferably the amount is 50%-100%.

[0017] The reaction temperature in step S2 is 0-80°C, and preferably 25-40°C; the reaction time is 1-24 hours, and preferably 1-12 hours. The post-treatment of the reaction liquid obtained in step S2 includes precipitation, washing, and drying of the reaction liquid obtained in step S2 to obtain the hydroxylated eucommia ulmoides gum.

[0018] Further, in step S3, the boronic acid derivative crosslinking agent includes one or more of o-aminobenzoic acid, 2-hydroxymethylbenzoic acid, 1,3-benzenediboronic acid, 2-(methoxycarbonyl)benzoic acid, 4-ethoxycarbonylbenzoic acid, 4-carboxybenzoic acid, 3-aminobenzoic acid, 4-acetyloxybenzoic acid, 4-carboxy-3-fluorobenzoic acid, 3-carboxybenzoic acid, and 1,4-benzenediboronic acid; the amount of the boronic acid derivative crosslinking agent is 0.1%-10% of the mass of the hydroxylated eucommia ulmoides gum, and preferably the amount is 0.5%-5%.

[0019] Further, in step S3, the cross-linking forming includes hot-pressing after mechanical blending or solidification forming after solution blending; the hot-pressing has a pressure of 10-15 MPa, a temperature of 100-150 DEG C and a time of 10-60 minutes; the solidification forming uses one or more of toluene, xylene, chlorobenzene, tetrahydrofuran, chloroform, n-hexane and petroleum ether as a solvent, and generally has a normal temperature and is formed after the solvent is completely volatilized.

[0020] As one of the specific embodiments of the present application, the preparation method of the reconfigurable Eucommia ulmoides Oliv. bidirectional shape memory material includes: dissolving Eucommia ulmoides Oliv. in an organic solvent to prepare a solution, adding an organic acid and a peroxide, and reacting at 25-40 DEG C for 1-8 hours to obtain an intermediate product C. Subsequently, a metal halide and deionized water are added, and the reaction is carried out at 25-40 DEG C for 1-12 hours, and then the hydroxylated Eucommia ulmoides Oliv. with hydroxyl groups is obtained through precipitation, washing and drying. The hydroxylated Eucommia ulmoides Oliv. and a boric acid derivative are mixed on an open mill, and vulcanization is carried out on a vulcanization instrument at a pressure of 10-15 MPa and a temperature of 100-150 DEG C for 10-60 minutes to obtain the reconfigurable Eucommia ulmoides Oliv. bidirectional shape memory material; or the reconfigurable Eucommia ulmoides Oliv. bidirectional shape memory material is obtained after the organic solvent is completely volatilized at normal temperature.

[0021] The reconfigurable Eucommia ulmoides Oliv. bidirectional shape memory material is applied to the fields of biological medicine and intelligent sensing.

[0022] The present application has the following beneficial effects:

[0023] 1. The reconfigurable Eucommia ulmoides Oliv. bidirectional shape memory material provided by the present application has a three-dimensional network structure with dynamic borate ester bond cross-linking by introducing hydroxyl groups into the molecular chain of Eucommia ulmoides Oliv. and reacting with a boric acid derivative cross-linking agent. The material prepared by the present application has excellent single-direction shape memory function relying on the crystallization-melting of Eucommia ulmoides Oliv. More importantly, the material prepared by the present application also has bidirectional (reversible) shape memory function relying on the crystallization-induced elongation and melting-induced contraction of the molecular chain of Eucommia ulmoides Oliv. under stress. Unlike traditional covalent bond cross-linking (such as sulfur or DCP) Eucommia ulmoides Oliv. shape memory materials, the present application relies on the cross-linking reaction of dynamic borate ester bond to endow the material with reconfigurable characteristics and self-repairing performance. The reconfigurable Eucommia ulmoides Oliv. bidirectional shape memory material prepared by the present application has important application prospects in the fields of biological medicine and intelligent sensing.

[0024] 2. The present application introduces hydroxyl groups into the molecular chain of Eucommia ulmoides Oliv. through double bond oxidation and ring-opening reaction, and then cross-links with a boric acid derivative to obtain a Eucommia ulmoides Oliv. material with reconfigurability, self-repairing performance and bidirectional shape memory function. The whole preparation method is simple and easy to operate, has high controllability, and has important significance for the preparation of multifunctional Eucommia ulmoides Oliv. intelligent materials. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present application or the prior art, the drawings required to be used in the following embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0026] Figure 1 The Fourier infrared spectrum of the hydroxylated eucommia ulmoides rubber and the reconfigurable eucommia ulmoides rubber bidirectional shape memory material prepared in Example 1;

[0027] Figure 2 The shape memory curve of the reconfigurable eucommia ulmoides rubber bidirectional shape memory material prepared in Example 2;

[0028] Figure 3 The shape memory process and permanent shape reconfiguration process photos of the reconfigurable eucommia ulmoides rubber bidirectional shape memory material prepared in Example 2;

[0029] Figure 4 The bidirectional shape memory process photo of the reconfigurable eucommia ulmoides rubber bidirectional shape memory material prepared in Example 2;

[0030] Figure 5 The self-repairing process photo of the reconfigurable eucommia ulmoides rubber bidirectional shape memory material prepared in Example 3. DETAILED DESCRIPTION

[0031] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in combination with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0032] Example 1

[0033] The present embodiment provides a preparation method of a reconfigurable eucommia ulmoides rubber bidirectional shape memory material, comprising:

[0034] (1) 10 g of eucommia ulmoides rubber is dissolved in organic solvent toluene to prepare a 5% solution, 8 mmol of butyric acid and 8 mmol of hydrogen peroxide are added, and the reaction is carried out at 40℃ for 4 h to obtain an intermediate product C;

[0035] (2) 0.5 g of palladium chloride and 10 g of deionized water are added, and the reaction is carried out at 30℃ for 5 h; after precipitation, washing and drying with organic solvent ethanol, the hydroxylated eucommia ulmoides rubber is obtained, and the molar content of hydroxyl is about 2%.

[0036] (3) Mixing the hydroxylated guttapercha and 1,3-benzene diboronic acid (1,3-benzene diboronic acid dosage is 2% of the mass of the hydroxylated guttapercha) on an open mill, and vulcanizing on a vulcanizing instrument at a pressure of 15 MPa and a temperature of 150°C for 10 minutes to obtain the reconfigurable guttapercha bidirectional shape memory material.

[0037] The Fourier infrared spectrum (FTIR) of the hydroxylated guttapercha and the reconfigurable guttapercha bidirectional shape memory material is shown in Figure 1 The peak at 3437 cm -1 is a hydroxyl stretching vibration peak, and after the formation of the borate ester bond by 1,3-benzene diboronic acid crosslinking, the peak intensity is reduced.

[0038] Example 2

[0039] The present embodiment provides a preparation method of a reconfigurable guttapercha bidirectional shape memory material, comprising:

[0040] (1) Dissolving 20 g of guttapercha in chlorobenzene to obtain a 4% solution, adding 12 mmol of acetic acid and 12 mmol of peracetic acid, and reacting at 30°C for 5 h to obtain an intermediate product C;

[0041] (2) Adding 0.6 g of aluminum chloride and 15 g of deionized water, and reacting at 40°C for 3 h; precipitating, washing, and drying by using an organic solvent ethanol to obtain the hydroxylated guttapercha, and the hydroxyl molar content is about 3.1%.

[0042] (3) Mixing the hydroxylated guttapercha and 3-aminobenzene boronic acid (3-aminobenzene boronic acid dosage is 1.7% of the mass of the hydroxylated guttapercha) on an open mill, and vulcanizing on a vulcanizing instrument at a pressure of 15 MPa and a temperature of 140°C for 15 minutes to obtain the reconfigurable guttapercha bidirectional shape memory material.

[0043] The shape memory curve of the reconfigurable guttapercha bidirectional shape memory material prepared in the present embodiment is shown in Figure 2 , and the shape memory fixing rate and the recovery rate are both greater than 95%, which shows excellent unidirectional shape memory performance.

[0044] The photos of the shape memory process and the permanent shape reconfiguration process of the reconfigurable guttapercha bidirectional shape memory material prepared in the present embodiment are shown in Figure 3 . By applying stress after heating to 60°C, the permanent shape A can be edited into a temporary shape B; then by cooling to -20°C, the temporary shape B can be fixed; when heated to 60°C again, the material can automatically recover to the permanent shape A.

[0045] Permanent shape A can be reconfigured into permanent shape C by heating to 140℃ and applying stress for 20 minutes. Permanent shape C can still be edited into temporary shape D by heating to 60℃ and then applying stress and subsequently cooling to -20℃, and automatically revert to permanent shape C under temperature stimulus to achieve shape memory function.

[0046] The bidirectional shape memory process of the reconfigurable eucommia rubber bidirectional shape memory material prepared in this embodiment is shown in Figure 4 The sample can be elongated to 3.3 cm by heating to 60℃ and hanging a 200g weight below it, and can be elongated to 4.6 cm by cooling to -20℃. With the temperature alternating between 60℃ and -20℃, the elongation of the sample can also reversibly change between 3.3 cm and 4.6 cm. Thus, the reconfigurable eucommia rubber bidirectional shape memory material prepared in the present application indeed exhibits good bidirectional shape memory function.

[0047] Example 3

[0048] This embodiment provides a preparation method of a reconfigurable eucommia rubber bidirectional shape memory material, comprising:

[0049] (1) 10g of eucommia rubber is dissolved in organic solvent tetrahydrofuran to prepare a 5% solution, 6mmol of propionic acid and 6mmol of peroxobenzoic acid are added, and the reaction is carried out at 40℃ for 3h to obtain intermediate product C;

[0050] (2) 0.2g of zirconium chloride and 9g of deionized water are added, and the reaction is carried out at 25℃ for 4h; after precipitation, washing and drying with organic solvent ethanol, hydroxylated eucommia rubber is obtained, and the molar content of hydroxyl is about 1.4%.

[0051] (3) The hydroxylated eucommia rubber and 2-(methoxycarbonyl) phenylboronic acid are dissolved in tetrahydrofuran (the amount of 2-(methoxycarbonyl) phenylboronic acid is 1.8% of the mass of the hydroxylated eucommia rubber), poured into a tetrafluoroethylene mold, and placed at room temperature for 48h to obtain the reconfigurable eucommia rubber bidirectional shape memory material.

[0052] The self-repairing process photos of the reconfigurable eucommia rubber bidirectional shape memory material prepared in this embodiment are shown in Figure 5 Two sample bars are cut from the middle and spliced together, and the repaired sample bar can bear a weight of 1kg after self-repairing at 80℃ for 12h.

[0053] Example 4

[0054] This embodiment provides a preparation method of a reconfigurable eucommia rubber bidirectional shape memory material, comprising:

[0055] (1) 15 g of eucommia ulmoides gum was dissolved in organic solvent n-hexane to form a 3% solution, 7 mmol of butyric acid and 6 mmol of hydrogen peroxide were added, and the mixture was reacted at 30°C for 4 h to obtain intermediate product C;

[0056] (2) 0.3 g of aluminum chloride and 10 g of deionized water were added, and the mixture was reacted at 35°C for 2 h; the product was precipitated, washed and dried by using organic solvent ethanol to obtain hydroxylated eucommia ulmoides gum, and the molar content of hydroxyl group was about 3.3%.

[0057] (3) The hydroxylated eucommia ulmoides gum and 1,4-benzenediol were dissolved in chloroform (the amount of 1,4-benzenediol was 2% of the mass of the hydroxylated eucommia ulmoides gum), and the mixture was poured into a teflon mold and placed at room temperature for 36 h to obtain the reconfigurable eucommia ulmoides gum bidirectional shape memory material.

[0058] Example 5

[0059] The embodiment provides a preparation method of a reconfigurable eucommia ulmoides gum bidirectional shape memory material, which comprises the following steps:

[0060] (1) 5 g of eucommia ulmoides gum was dissolved in organic solvent petroleum ether to form a 5% solution, 4 mmol of formic acid and 4 mmol of peroxyacetic acid were added, and the mixture was reacted at 25°C for 6 h to obtain intermediate product C;

[0061] (2) 0.2 g of iron chloride and 5 g of deionized water were added, and the mixture was reacted at 25°C for 9 h; the product was precipitated, washed and dried by using organic solvent ethanol to obtain hydroxylated eucommia ulmoides gum, and the molar content of hydroxyl group was about 1.1%.

[0062] (3) The hydroxylated eucommia ulmoides gum and 4-ethoxycarbonylphenylboronic acid were mixed on an open mill (the amount of 4-ethoxycarbonylphenylboronic acid was 1.5% of the mass of the hydroxylated eucommia ulmoides gum), and the mixture was vulcanized on a vulcanizer at a pressure of 15 MPa and a temperature of 100°C for 10 minutes to obtain the reconfigurable eucommia ulmoides gum bidirectional shape memory material.

[0063] Example 6

[0064] The embodiment provides a preparation method of a reconfigurable eucommia ulmoides gum bidirectional shape memory material, which comprises the following steps:

[0065] (1) 15 g of eucommia ulmoides gum was dissolved in organic solvent chloroform to form a 2% solution, 6 mmol of formic acid and 4 mmol of hydrogen peroxide were added, and the mixture was reacted at 30°C for 7 h to obtain intermediate product C;

[0066] (2) 0.5 g of iron bromide and 15 g of deionized water were added, and the mixture was reacted at 25°C for 12 h; the product was precipitated, washed and dried by using organic solvent ethanol to obtain hydroxylated eucommia ulmoides gum, and the molar content of hydroxyl group was about 4%.

[0067] (3) mixing the hydroxylated eucommia ulmoides gum and 2-(methoxycarbonyl) phenylboronic acid (2-(methoxycarbonyl) phenylboronic acid is 2% of the mass of the hydroxylated eucommia ulmoides gum) on an open mill, and vulcanizing on a vulcanizing instrument at a pressure of 12 MPa and a temperature of 130 DEG C for 30 minutes to obtain the reconfigurable eucommia ulmoides gum bidirectional shape memory material.

[0068] Example 7

[0069] The embodiment provides a preparation method of a reconfigurable eucommia ulmoides gum bidirectional shape memory material, comprising the following steps:

[0070] (1) dissolving 12 g of eucommia ulmoides gum in an organic solvent dimethylbenzene to prepare a 4% solution, adding 6 mmol of butyric acid and 6 mmol of hydrogen peroxide, and reacting at 40 DEG C for 3 h to obtain an intermediate product C;

[0071] (2) adding 0.6 g of zirconium chloride and 10 g of deionized water, and reacting at 25 DEG C for 8 h; precipitating, washing and drying by using an organic solvent ethanol to obtain the hydroxylated eucommia ulmoides gum, and the molar content of the hydroxyl group is about 6%.

[0072] (3) dissolving the hydroxylated eucommia ulmoides gum and 4-carboxyl-3-fluorophenylboronic acid (4-carboxyl-3-fluorophenylboronic acid is 3% of the mass of the hydroxylated eucommia ulmoides gum) in n-hexane, pouring into a tetrafluoroethylene mold, and placing at room temperature for 48 h to obtain the reconfigurable eucommia ulmoides gum bidirectional shape memory material.

[0073] In summary, the reconfigurable eucommia ulmoides gum bidirectional shape memory material, the preparation method and the application thereof provided by the embodiment are prepared by introducing the hydroxyl group into the molecular chain of the eucommia ulmoides gum and reacting with the boronic acid derivative crosslinking agent, and a three-dimensional network structure with a dynamic borate ester bond crosslinking is prepared. The material prepared by the embodiment has excellent single shape memory function relying on the crystallization-melting of the eucommia ulmoides gum. The material prepared by the embodiment also has bidirectional (reversible) shape memory function relying on the crystallization-induced elongation and melting-induced contraction of the molecular chain of the eucommia ulmoides gum under stress. The permanent shape of the material prepared by the embodiment can be reconfigured, and the material has self-repairing performance relying on the bond exchange reaction of the dynamic borate ester bond.

[0074] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A reconfigurable Eucommia gum bidirectional shape memory material, characterized by: A three-dimensional network structure is formed by cross-linking hydroxylated eucommia gum and a boric acid derivative cross-linking agent through dynamic borate ester bonds, wherein the amount of the boric acid derivative cross-linking agent is 0.1%-10% of the mass of the hydroxylated eucommia gum; The hydroxylated eucommia gum is obtained by oxidizing and hydroxylating double bonds of eucommia gum, and the molar content of hydroxyl groups in the hydroxylated eucommia gum is 0.1%-20%; The shape memory material relies on the crystallization-melting of eucommia gum and the crystallization-induced elongation and melting-induced contraction of eucommia gum molecular chains under stress, and the shape memory material has a two-way shape memory function.

2. The reconfigurable Eucommia gum bidirectional shape memory material according to claim 1, characterized in that: The molar content of hydroxyl groups in the hydroxylated eucommia gum is 1%-15%.

3. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 1 or 2, characterized in that: The following steps are involved: S1. oxidizing the carbon-carbon double bond in the Eucommia ulmoides gum molecular chain by an oxidant to obtain an oxidized intermediate; S2. Under the action of metal halide and deionized water, the oxidation intermediate is converted into hydroxylated eucommia gum; S3. cross-linking the hydroxylated eucommia gum with a boric acid derivative cross-linking agent to obtain the reconfigurable eucommia gum bidirectional shape memory material.

4. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 3, characterized in that: In step S1, the oxidation reaction further includes an organic acid catalyst; the organic acid catalyst includes one or more of formic acid, acetic acid, propionic acid, butyric acid, and benzoic acid; the molar ratio of the organic acid catalyst to the carbon-carbon double bond of the eucommia gum is (0.01~0.20):

1.

5. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 4, characterized in that: The molar ratio of the organic acid catalyst to the carbon-carbon double bond of the eucommia gum is (0.01-0.10):

1.

6. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 3, characterized in that: In step S1, the oxidant is a peroxide, including one or more of perbenzoic acid, hydrogen peroxide, and peracetic acid; the molar ratio of the oxidant to the carbon-carbon double bond of the eucommia gum is (0.01-0.20):

1.

7. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 6, characterized in that: The molar ratio of the oxidant to the carbon-carbon double bond of the eucommia gum is (0.01-0.10):

1.

8. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 3, characterized in that: In step S1, the solvent of the oxidation reaction is one or more of toluene, xylene, chlorobenzene, tetrahydrofuran, chloroform, n-hexane, and petroleum ether; the reaction temperature is 0-80° C.; the reaction time is 1-24 hours; and the mass concentration of the eucommia gum in the solvent is 1-10%.

9. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 8, characterized in that: In step S1, the oxidation reaction temperature is 25-40° C. and the reaction time is 1-8 hours.

10. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 3, characterized in that: In step S2, the metal halide includes one or more of ferric chloride, cupric chloride, ferrous chloride, cuprous chloride, silver chloride, palladium chloride, rhodium chloride, zirconium chloride, aluminum chloride, zinc chloride, copper bromide, and ferric bromide; the amount of the metal halide is 1%-10% of the mass of the oxidation intermediate product; the amount of the deionized water is 10%-200% of the mass of the eucommia gum.

11. The method for preparing a reconfigurable Eucommia gum bidirectional shape memory material according to any one of claims 3 to 10, characterized in that: In step S3, the boronic acid derivative cross-linking agent includes one or more of o-aminophenylboronic acid, 2-hydroxymethylphenylboronic acid, 1,3-phenylenediboronic acid, 2-(methoxycarbonyl)phenylboronic acid, 4-ethoxycarbonylphenylboronic acid, 4-carboxylphenylboronic acid, 3-aminophenylboronic acid, 4-acetoxyphenylboronic acid, 4-carboxyl-3-fluorophenylboric acid, 3-carboxylphenylboric acid, and 1,4-phenylenediboric acid; the amount of the boronic acid derivative cross-linking agent used is 0.1-10% of the mass of the hydroxylated eucommia gum.

12. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 11, characterized in that: In step S3, the amount of the boric acid derivative cross-linking agent is 0.5-5% of the mass of the hydroxylated eucommia gum.

13. The method for preparing the reconfigurable Eucommia gum bidirectional shape memory material according to claim 3, characterized in that: In step S3, the cross-linking molding includes hot pressing molding after mechanical blending or curing molding after solution blending; the pressure of the hot pressing molding is 10-15 MPa, the temperature is 100-150° C., and the time is 10-60 minutes; the solvent for the curing molding is one or more of toluene, xylene, chlorobenzene, tetrahydrofuran, chloroform, n-hexane, and petroleum ether.

14. A use of the reconfigurable Eucommia gum bidirectional shape memory material according to claim 1 or 2, or the reconfigurable Eucommia gum bidirectional shape memory material obtained by the preparation method of any one of claims 3 to 13, characterized in that: Used in the fields of biomedicine and intelligent sensing for non-disease diagnosis and treatment purposes.

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