CN108559054B

CN108559054B - Shape memory polymer and preparation method and application thereof

Info

Publication number: CN108559054B
Application number: CN201810409030.6A
Authority: CN
Inventors: 王晓猛; 赵军; 张忠; 张晖; 刘雅芸; 赵玲玉
Original assignee: National Center for Nanosccience and Technology China
Current assignee: National Center for Nanosccience and Technology China
Priority date: 2018-05-02
Filing date: 2018-05-02
Publication date: 2021-02-02
Anticipated expiration: 2038-05-02
Also published as: CN108559054A

Abstract

The invention provides a method for preparing a shape memory polymer by a one-step method, which comprises the following steps: the preparation method comprises the steps of preparing solutions of diisocyanate, a crosslinking degree regulator and a catalyst respectively, adding the solutions into polydiol in sequence, stirring to mix the solutions uniformly to obtain a pre-reaction solution, and curing the pre-reaction solution at 80-100 ℃ to obtain the shape memory polymer.

Description

Shape memory polymer and preparation method and application thereof

Technical Field

The invention relates to the field of synthesis of high molecular materials, in particular to a shape memory polymer and a preparation method and application thereof.

Background

The shape memory polymer is an intelligent polymer which can fix a temporary shape and can return to an initial shape under the action of external stimulation (such as stimulation of heat, light, electricity, magnetism and the like), and particularly the shape memory polymer taking polyurethane as a main component has excellent performances such as large deformation amount, low density, adjustable return temperature and the like, so the polyurethane type shape memory polymer has good application prospects in the fields of biomedicine, intelligent wearing, aerospace and the like.

Shape memory materials, particularly shape memory polymers capable of biological applications, are generally required to have the following properties: (1) the appropriate transition temperature is 40-45 ℃ considering that the shape memory effect does not occur or does not occur significantly in the organism environment, but occurs at a temperature slightly higher than the body temperature and ensures that the highest recovery temperature does not damage organism tissues; (2) good biocompatibility, the shape memory material needs to be nontoxic and free of catalyst and solvent residue, does not cause adverse reaction in organisms, and can be absorbed or discharged out of the bodies through degradation according to needs; (3) has good shape memory effect, including good shape fixation rate and shape recovery rate, larger recoverable deformation, fast recovery rate and the like, so as to ensure the stability and safety in the use process.

So far, the main method for preparing polyurethane-type shape memory polymer is mainly to mix polyol, diisocyanate and catalyst in advance, carry out chain extension reaction at lower temperature and in the presence of chain extender, and then carry out cross-linking curing reaction at high temperature and in the presence of cross-linking agent to obtain the required shape memory polymer, the two-step method has the problems of long time consumption, uneven cross-linking of products, recoverable deformation, low recovery rate and the like, for example, CN101475677A discloses a linear multi-block copolymer with shape memory capacity, and discloses a method for preparing the copolymer by using a prepolymer-chain extension two-step method, the method comprises the steps of preparing isocyanate-terminated copolymer macromolecular prepolymer under the action of organic tin catalyst, adding copolymer macromolecular diol to carry out chain extension for a certain time, the method has the problems of complex process, residual catalyst in the product, poor shape memory effect and thermal mechanical property of the product and the like; CN104710576A discloses a similar method for preparing thermotropic crosslinking type shape memory polyurethane, wherein the method comprises the steps of preparing thermoplastic polyurethane by a prepolymer-chain extension two-step method, and then carrying out thermal crosslinking on the obtained thermoplastic polyurethane and a bifunctional crosslinking agent through melt mixing or solution mixing to prepare the shape memory polyurethane.

In view of the foregoing, there is a need in the art for an improved method for preparing polyurethane-type shape memory polymers in a two-step process, as is commonly used in the art, to provide a new one-step method for preparing shape memory polymers, which method is characterized by the following features: (1) the synthesis process is simple, energy-saving and environment-friendly, and is beneficial to industrial production; (2) the catalyst is non-toxic or has low residue, and the preparation can be used in the field of biological medicine; (3) to further satisfy specific needs, such as blending with functional nanoparticles, etc., the method requires that the added material be distributed uniformly in the shape memory polymer to prepare a shape memory material having multiple functions and multiple stimulus responses.

Disclosure of Invention

In view of the disadvantages of the prior art, it is an object of the present invention to provide a method for preparing a shape memory polymer in one step, the method comprising the steps of:

respectively preparing diisocyanate, a crosslinking degree regulator and a catalyst into solutions, sequentially adding the solutions into polydiol, stirring to uniformly mix the solutions to obtain a pre-reaction solution, and curing the pre-reaction solution at 80-100 ℃ (for example, 82 ℃, 84 ℃, 86 ℃, 88 ℃, 90 ℃, 92 ℃, 94 ℃, 96 ℃ or 98 ℃ and the like) to obtain the shape memory polymer.

The polyurethane shape memory polymer prepared by the invention is composed of a flexible crosslinking network and a polymer crystalline region contained in the flexible crosslinking network, the formation of the shape memory polymer is greatly influenced by the crosslinking degree, the crosslinking degree is mainly controlled by parameters such as reaction temperature, reaction time and the like in the preparation process, when the crosslinking degree is too high, the material loses shape plasticity and shows poor shape fixing rate, and when the crosslinking degree is too low, the material shows poor shape recovery rate.

In the preparation method, the one-step reaction is carried out at the temperature of 80-100 ℃, so that the crosslinking degree of the product is appropriate and the reaction is controllable, and the traditional low-temperature prepolymerization-high-temperature chain extension two-step process with complicated operation can be replaced, and the efficient preparation of the shape memory polymer is realized.

The preparation method can effectively avoid side reactions such as excessive crosslinking, cyclization and the like at higher reaction temperature, further improve the recoverability of the product, and change the reaction flow or select the polyhydric alcohol above the polyhydric alcohol, so that the product with higher shape recovery rate and recovery deformation is difficult to obtain.

In the preparation method of the invention, the recoverability of the product can be further improved by selecting a proper reactant proportion.

Preferably, the molar ratio of the diisocyanate to the crosslinking degree modifier is 1:0.2 to 1.2, for example 1:0.3, 1:0.5, 1:0.7, 1:0.9 or 1: 1.1.

Preferably, the molar ratio of the diisocyanate to the polyglycol is 1:0.2 to 1.4, for example 1:0.3, 1:0.5, 1:0.7, 1:0.9, 1:1.1 or 1: 1.3.

Preferably, the catalyst is an organobismuth catalyst.

Preferably, the catalyst is added in an amount of 0.1 to 0.5%, for example, 0.15%, 0.25%, 0.35%, or 0.45% by weight based on the total weight of the diisocyanate, the crosslinking degree modifier, and the polyglycol.

Preferably, the mixed solution is further added with functional nanoparticles, and the introduction of the functional nanoparticles does not affect the shape memory capacity of the product, but can enable the prepared shape memory polymer product to have corresponding performance of multiple stimuli, such as electric, optical or magnetic stimulus response capacity, so that the application field of the product is wider.

Preferably, the functional nanoparticles are added in an amount of 0.01 to 10% by weight, for example, 0.05%, 0.1%, 0.5%, 1.0%, 1.5%, 2.5%, 3.5%, 4.5%, 5.5%, 6.5%, 7.5%, 8.5%, or 9.5% by weight, based on the total weight of the diisocyanate, the crosslinking degree modifier, and the polyglycol.

Preferably, the functional nanoparticles are any one of carbon nanotubes, nano graphene oxide, nano carbon black or nano ferroferric oxide.

Preferably, the diisocyanate is any one of isophorone diisocyanate, diphenylmethane diisocyanate or toluene diisocyanate or a mixture of at least two of the isophorone diisocyanate, the diphenylmethane diisocyanate or the toluene diisocyanate.

Preferably, the polyglycol is any one or a mixture of at least two of polycaprolactone diol, polylactic acid diol or polyether diol.

Preferably, the number average molecular weight of the polyglycol is 1000-3000 Da, such as 1100Da, 1300Da, 1500Da, 1700Da, 1900Da, 2100Da, 2300Da, 2500Da, 2700Da, or 2900Da, and the like, and the polyglycol with the number average molecular weight is selected to enable the segment chain average molecular weight of the flexible chain in the product to be uniform, so that the recovery performance of the product is further improved.

Preferably, the crosslinking degree regulator is any one or a mixture of at least two of alkane compounds containing at least three hydroxyl groups, and the effect of regulating the crosslinking degree can be better realized by selecting trihydroxy or polyhydroxy alkane compounds as the crosslinking degree regulator.

Preferably, the crosslinking degree modifier is glycerol and/or trimethylolpropane.

Preferably, the solvent of the mixed solution is N, N-dimethylformamide and/or acetone.

Preferably, the solvent of the mixed solution is an anhydrous solvent.

Preferably, the stirring time is 3-15 min, such as 4min, 5min, 6min, 7min, 8min, 10min, 12min or 14min, preferably 5-10 min.

Preferably, the rotation speed of the stirring is 50-200 r/min, such as 55 r/min, 65 r/min, 85 r/min, 105 r/min, 125 r/min, 145 r/min, 165 r/min, 185 r/min or 195 r/min.

Preferably, the polyglycol is also dried under vacuum before being added to the mixed solution.

Preferably, the vacuum drying time is 3-10 h, such as 4h, 5h, 6h, 7h, 8h or 9 h.

Preferably, the temperature for curing the pre-reaction solution is 90-100 ℃, and further preferably 92-98 ℃.

Preferably, the time for curing the pre-reaction solution is 2 to 20 hours, for example, 3 hours, 5 hours, 7 hours, 9 hours, 11 hours, 13 hours, 15 hours, 17 hours or 19 hours, and the like, and more preferably 3 to 10 hours.

Preferably, in order to further control the crosslinking degree of the product and obtain a product with better recovery performance, the pre-reaction solution is cured at 82-88 ℃ for at least 3 hours and then cured at 92-98 ℃ for at least 10 hours.

Preferably, the pre-reaction solution is subjected to a vacuum treatment to remove the solvent and residual gases in the solution before solidification.

Preferably, the time of the vacuum treatment is 2 to 10min, for example, 3min, 4min, 5min, 6min, 7min, 8min or 9min, and more preferably 3 to 8 min.

The second purpose of the invention is to provide the shape memory polymer prepared by the method, wherein the shape fixing rate of the shape memory polymer is more than or equal to 98%, the shape recovery rate is more than or equal to 95%, the recoverable deformation is more than or equal to 900%, and the recovery time within 40-45 ℃ is less than or equal to 8 s.

The invention also aims to provide application of the shape memory polymer, and the shape memory polymer has shape plasticity and shape recoverability, so that the shape memory polymer can be used for preparing an in vivo implanted material, a flexible device, a control device or a sensing device.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the invention, by selecting proper reaction conditions, the polyurethane shape memory material with the shape fixing rate of more than or equal to 98%, the shape recovery rate of more than or equal to 95%, the recoverable deformation of 900% and the recovery time of less than or equal to 8s at 40-45 ℃ can be obtained.

(2) Compared with the traditional method for preparing the polyurethane shape memory material by two steps of low-temperature prepolymerization, high-temperature crosslinking or chain extension, curing and the like, the invention creatively provides the method for preparing the polyurethane shape memory material by the one-step method, the method is suitable for most of isocyanate and polyglycol systems, and has the advantages of simplicity, convenience, energy conservation, environmental protection, no toxicity, high efficiency, suitability for industrial production and the like.

(3) The method provided by the invention can be used for preparing the shape memory polymer suitable for the field of biomedicine, and can also be suitable for preparing the shape memory polymer loaded with functional nanoparticles, so that the preparation of the shape memory polymer which is corresponding to multiple stimuli and can be biologically applied is realized.

Drawings

FIG. 1 shows the initial shape (left) of the shape memory polymer 1 obtained in example 1 prepared in a (NCNST) -like mold, optionally stretched above the transition temperature, the resulting pattern fixed at room temperature (middle) and the shape after incubation at 43 ℃ for 8s (right).

FIG. 2 is a heat flow-temperature curve of the shape memory polymer 1 obtained in example 1, measured by a thermal transition temperature test.

FIG. 3 is a graph showing the temperature, stress and strain of the shape memory polymer 1 obtained in example 1 in the shape fixation ratio and shape recovery ratio tests over time.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

Shape memory polymer 1 was prepared by the following method:

4.5g (20mmol) of isophorone diisocyanate and 1.3g (9.7mmol) of trimethylolmethane were dissolved in 50mL of a solution

Preparing a mixed solution from acetone anhydrous solvent treated by a molecular sieve, and catalyzing 12g of polycaprolactone diol with the number average molecular weight of 1000Da (equivalent to 12mmol) and 88mg of organic bismuthAdding the agent into the mixed solution, stirring at the rotating speed of 200 revolutions per minute for 15 minutes to uniformly mix the agent and the mixed solution to obtain a pre-reaction solution, placing the pre-reaction solution into a drying oven, curing at 85 +/-2 ℃ for 3 hours, then curing at 95 +/-3 ℃ for 10 hours, gradually volatilizing an acetone solvent in the curing process, and obtaining the shape memory polymer 1 after the curing reaction is finished.

Example 2

Shape memory polymer 2 was prepared by the following method:

the only difference from example 1 was that 2.2g (23.8mmol) of glycerin was added to the reaction system in place of trimethylolmethane.

Example 2 shape memory polymer 2 was obtained.

Example 3

Shape memory polymer 3 was prepared by the following method:

the only difference from example 1 is that the amount of trimethylolmethane added is 0.54g (4 mmol).

Example 3A shape memory polymer 3 was obtained.

Example 4

Shape memory polymer 4 was prepared by the following method:

the only difference from example 1 is that 5g (20mmol) of diphenylmethane diisocyanate were used instead of isophorone diisocyanate and 12g (corresponding to 4mmol) of polylactic acid diol having a number average molecular weight of 3000 were used instead of polycaprolactone diol.

Example 4 shape memory polymer 4 was obtained.

Example 5

Shape memory polymer 5 was prepared by the following method:

the only difference from example 1 was that the amount of polycaprolactone diol added was 28g (equivalent to 28mmol) and the amount of organobismuth catalyst added was 34 mg.

Example 5A shape memory polymer 5 was obtained.

Example 6

Shape memory polymer 6 was prepared by the following method:

the only difference from example 1 is that 20mg of nano graphene oxide with an average particle size of 45nm is further added to the mixed solution, the stirring time is 3min, and the stirring speed is 200 rpm.

Example 6A shape memory polymer 6 was obtained.

Example 7

Shape memory polymer 7 was prepared by the following method:

the only difference from example 1 is that 1.7g of nano-sized ferroferric oxide particles with an average particle size of 120nm are further added to the mixed solution, and the pre-reaction solution is subjected to vacuum drying treatment at room temperature for 3min before solidification to remove acetone remaining in the system.

Example 7A shape memory polymer 7 was obtained.

Example 8

Shape memory polymer 8 was prepared by the following method:

the only difference from example 1 was that N, N-dimethylformamide was used instead of acetone as a solvent for the mixed solution, and the pre-reaction solution was subjected to vacuum drying treatment at 80 ℃ for 8min before curing to remove N, N-dimethylformamide remaining in the system.

Example 8A shape memory polymer 8 was obtained.

Example 9

Shape memory polymer 9 was prepared by the following method:

the only difference from example 1 is that the polycaprolactone diol needs to be vacuum dried for 3h before being added into the mixed solution to remove the water, and the curing process of the pre-reaction solution is to be directly cured at the constant temperature of 82 ℃ for 20 h.

Example 9A shape memory polymer 9 was obtained.

Example 10

Shape memory polymer 10 is prepared by the following method:

the only difference from example 1 is that the polycaprolactone diol needs to be vacuum dried for 10h before being added into the mixed solution to remove the water, and the curing process of the pre-reaction solution is to be directly cured at constant temperature of 98 ℃ for 3 h.

Example 10A shape memory polymer 10 was obtained.

Example 11

The shape memory polymer 11 is prepared by the following method:

the only difference from example 1 is that the amount of trimethylolmethane added is 0.5g (3.7 mmol).

Example 11A shape memory polymer 11 was obtained.

Example 12

Shape memory polymer 12 is prepared by the following method:

the only difference from example 1 is that the amount of trimethylolmethane added is 3.5g (26 mmol).

Example 12A shape memory polymer 12 was obtained.

Example 13

The shape memory polymer 13 is prepared by the following method:

the only difference from example 1 is that the molecular weight of polycaprolactone diol is 4000Da and the amount of polycaprolactone diol added is 8g (2 mmol).

Example 13A shape memory polymer 13 was obtained.

Example 14

Shape memory polymer 14 is prepared by the following method:

the only difference from example 1 is that the molecular weight of polycaprolactone diol is 500Da and the amount of polycaprolactone diol added is 15g (30 mmol).

Example 14 a shape memory polymer 14 was obtained.

Comparative example 1

Shape memory polymer 15 is prepared by the following method:

the only difference from example 1 is that the curing process of the pre-reaction solution was a constant temperature curing directly at 105 ℃ for 2 h.

Comparative example 1 gave a shape memory polymer 15.

Comparative example 2

Shape memory polymer 16 was prepared by the following method:

the only difference from example 1 is that the curing process of the pre-reaction solution was a constant temperature curing at 75 ℃ for 22 h.

A shape memory polymer 16 was obtained in comparative example 1.

Comparative example 3

Shape memory polymer 17 was prepared by the following method:

4.5g (20mmol) of isophorone diisocyanate and 12g of polycaprolactone diol having a number average molecular weight of 1000Da (corresponding to 12mmol) are dissolved in 50mL

Preparing a mixed solution in an acetone anhydrous solvent treated by a molecular sieve, adding 1.3g (9.7mmol) of trimethylolmethane and 88mg of an organic bismuth catalyst into the mixed solution, stirring at a rotating speed of 200 rpm for 15min, uniformly mixing to obtain a pre-reaction solution, placing the pre-reaction solution in a drying oven, curing at 85 +/-2 ℃ for 3h, then curing at 95 +/-3 ℃ for 10h, gradually volatilizing the acetone solvent in the curing process, and obtaining the shape memory polymer 17 after the curing reaction is finished.

Comparative example 4

Shape memory polymer 18 is prepared by the following method:

Preparing a mixed solution in an acetone anhydrous solvent treated by a molecular sieve, carrying out chain extension reaction on the mixed solution at 55 ℃ for 8 hours, adding 1.3g (9.7mmol) of trimethylolmethane and 88mg of an organic bismuth catalyst, stirring at the rotating speed of 100 revolutions per minute for 20 minutes to uniformly mix the solution to obtain a pre-reaction solution, placing the pre-reaction solution in a drying oven, carrying out constant-temperature curing at 120 ℃ for 10 hours, and obtaining the shape memory polymer 18 after the curing reaction is finished.

The shape memory polymers 1 to 18 obtained in the above examples and comparative examples were subjected to characterization tests by the following test methods, and the test results are shown in Table 1:

(1) thermal transition temperature test

Respectively placing 5mg of the obtained shape memory polymer 1-18 in a Q2000 type Differential Scanning Calorimeter (DSC) produced by American TA company, circularly scanning at 0-120 ℃ for once to eliminate heat history, then uniformly heating to 100 ℃ from 0 ℃ at a heating rate of 5 ℃/min to obtain a heat flow-temperature curve, wherein the temperature corresponding to the peak top of the curve is the thermal transition temperature of the shape memory polymer material.

(2) Shape fixation and shape recovery test

The obtained shape memory polymers 1-18 are respectively made into sample strips with the width of 5mm and the length of 15mm, the sample strips are fixed in a Q2000 type dynamic thermal mechanical analysis (DMA) instrument manufactured by the American TA company, when the temperature of the DMA instrument is raised to the thermal transition temperature of a sample, applying 0.05MPa of stress to the sample strip, measuring the strain of the sample to be initial deformation after the strain of the sample is stable, then cooling the sample to 0 ℃, removing the stress, observing the deformation of the sample after the stress is removed, dividing the absolute value of the deformation after the initial deformation is subtracted by the shape fixing rate of the sample by the initial deformation, then heating the sample from 0 ℃ to the temperature above the thermal transition temperature of the sample, measuring the deformation after the sample is recovered after the deformation is stable, and dividing the absolute value of the deformation after the stress is removed and the recovered deformation by the deformation after the stress is removed to obtain a numerical value as the shape recovery rate of the sample.

(3) Maximum recoverable deformation test

Respectively manufacturing the obtained shape memory polymers 1-18 into sample strips with the width of 5mm and the length of 15mm, adopting the same test method in shape fixation rate and shape recovery rate tests, wherein the difference is that the stress applied to the sample strips can take any value, and when the stress is selected to enable the shape recovery rate of the measured sample to be less than 90%, the initial deformation of the sample is taken as the maximum value of recoverable deformation.

(4) Return time test

The obtained shape memory polymers 1-18 are respectively made into sample strips with the width of 5mm and the length of 15mm, the same test methods as those in the shape fixing rate and shape recovery rate tests are adopted, the difference is only that the time after the stress of the sample is removed is T0, the temperature of the sample is kept constant to be the thermal transition temperature of the sample, the shape recovery rate is observed, when the shape recovery rate is kept unchanged, the time is recorded as T1, and the difference between T1 and T0 is taken as the recovery time of the sample.

TABLE 1 comparison of the Properties of shape memory polymers 1-18

Wherein "-" indicates that the sample does not have shape memory so that the value cannot be obtained.

Taking the shape memory polymer 1 obtained in example 1 as an example, and fig. 1 shows the initial shape (left) obtained by preparing the shape memory polymer in a (NCNST) -like mold, randomly stretching the shape memory polymer above the transition temperature, fixing the obtained shape memory polymer at room temperature (middle) and the shape memory polymer after keeping the temperature at 43 ℃ for 8s (right), it can be seen that the shape memory polymer prepared by the invention has shape memory capability, and the shape memory capability is excellent, and can be quickly recovered to obtain a more complex pattern.

FIG. 2 is a heat flow-temperature curve obtained by a thermal transition temperature test of the shape memory polymer 1 obtained in example 1, wherein the thermal transition temperature can be obviously obtained to be about 43 ℃.

FIG. 3 is a graph showing the temperature, stress and strain changes with time in the shape memory rate and shape recovery rate test of the shape memory polymer 1 obtained in example 1, in which the shape memory-recovery process can be visually observed and the shape memory rate and shape recovery rate can be obtained.

As can be seen from Table 1, by selecting proper reaction conditions, the polyurethane shape memory material with the shape fixing rate of more than or equal to 98 percent, the shape recovery rate of more than or equal to 95 percent, the recoverable deformation of 900 percent and the recovery time of less than or equal to 8s at 40-45 ℃ can be obtained, and the performance of the obtained polymer material is obviously reduced or the polymer material has no shape memory capacity by changing the reaction conditions, such as changing the reaction temperature or the feeding sequence of reactants.

In summary, compared with the traditional two-step method of low-temperature prepolymerization, high-temperature crosslinking or chain extension, curing and the like for preparing the polyurethane shape memory material, the method for preparing the polyurethane shape memory material by the one-step method is creatively provided, is suitable for most of isocyanate and polyglycol systems, and has the advantages of simplicity, convenience, energy conservation, environmental protection, low toxicity, high efficiency, suitability for industrial production and the like.

The applicant states that the present invention is illustrated by the above examples of the process of the present invention, but the present invention is not limited to the above process steps, i.e. it is not meant that the present invention must rely on the above process steps to be carried out. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.

Claims

1. A one-step process for preparing a shape memory polymer, comprising the steps of:

respectively preparing diisocyanate, a crosslinking degree regulator and a catalyst into solutions, sequentially adding the solutions into polydiol, stirring to uniformly mix the solutions to obtain a pre-reaction solution, and curing the pre-reaction solution at 80-100 ℃ to obtain the shape memory polymer;

the molar ratio of the diisocyanate to the crosslinking degree regulator is 1: 0.2-1.2, and the catalyst is an organic bismuth catalyst.

2. The method according to claim 1, wherein the molar ratio of the diisocyanate to the polyglycol is 1:0.2 to 1.4.

3. The method according to claim 1 or 2, wherein the catalyst is added in an amount of 0.1 to 0.5% by weight based on the total weight of the diisocyanate, the crosslinking degree modifier and the polyglycol.

4. The method according to claim 1, wherein functional nanoparticles are further added to the mixed solution.

5. The method of claim 4, wherein the functional nanoparticles are added in an amount of 0.01 to 10 wt% based on the total weight of the diisocyanate, the crosslinking degree modifier, and the polyglycol.

6. The preparation method according to claim 4, wherein the functional nanoparticles are any one of carbon nanotubes, nano-graphene oxide, nano-carbon black or nano-ferroferric oxide.

7. The method according to claim 1, wherein the diisocyanate is any one or a mixture of at least two of isophorone diisocyanate, diphenylmethane diisocyanate, or toluene diisocyanate.

8. The method according to claim 1, wherein the polyglycol is any one or a mixture of at least two of polycaprolactone diol, polylactic acid diol, or polyether diol.

9. The method according to claim 1, wherein the number average molecular weight of the polyglycol is 1000 to 3000 Da.

10. The method according to claim 1, wherein the crosslinking degree modifier is any one of or a mixture of at least two of alkane compounds having at least three hydroxyl groups.

11. The method according to claim 10, wherein the crosslinking degree modifier is glycerin and/or trimethylolpropane.

12. The method according to claim 1, wherein the solvent of the mixed solution is N, N-dimethylformamide and/or acetone.

13. The method according to claim 1, wherein the solvent of the mixed solution is an anhydrous solvent.

14. The method according to claim 1, wherein the stirring time is 3 to 15 min.

15. The method according to claim 14, wherein the stirring time is 5 to 10 min.

16. The method according to claim 1, wherein the stirring is performed at a rotation speed of 50 to 200 rpm.

17. The method of claim 1, wherein the polyglycol is further subjected to vacuum drying prior to mixing with the other components.

18. The preparation method according to claim 17, wherein the vacuum drying time is 3 to 10 hours.

19. The method according to claim 1, wherein the temperature at which the pre-reaction solution is solidified is 90 to 100 ℃.

20. The method according to claim 19, wherein the temperature at which the pre-reaction solution is solidified is 92 to 98 ℃.

21. The preparation method according to claim 1, wherein the pre-reaction solution is solidified for 2 to 20 hours.

22. The method according to claim 21, wherein the pre-reaction solution is solidified for 3 to 10 hours.

23. The method of claim 1, wherein the pre-reaction solution is cured at 82-88 ℃ for at least 3 hours and then at 92-98 ℃ for at least 10 hours.

24. The method of claim 1, wherein the pre-reaction solution is further subjected to a vacuum treatment to remove residual gases in the solution and solvent before solidification.

25. The method according to claim 24, wherein the vacuum treatment is carried out for 2 to 10 min.

26. The method according to claim 25, wherein the vacuum treatment is performed for 3 to 8 min.

27. A shape memory polymer prepared by the method of any one of claims 1 to 26, wherein the shape memory polymer has a shape fixation rate of 98% or more, a shape recovery rate of 95% or more, a recoverable deformation rate of 900% or more, and a recovery time of 8s or less at 40 to 45 ℃.

28. Use of a shape memory polymer according to claim 27 for the preparation of an intracorporeal implant material, a flexible device, a control device or a sensing device.