CN113651992B

CN113651992B - Shape memory aerogel and preparation method thereof

Info

Publication number: CN113651992B
Application number: CN202110949222.8A
Authority: CN
Inventors: 程旭东; 何盼; 潘月磊
Original assignee: University of Science and Technology of China USTC
Current assignee: University of Science and Technology of China USTC
Priority date: 2021-08-18
Filing date: 2021-08-18
Publication date: 2022-12-30
Anticipated expiration: 2041-08-18
Also published as: CN113651992A

Abstract

The invention provides a preparation method of a shape memory aerogel, which comprises the following steps: step a), carrying out a first reaction of a sulfhydryl reagent and an olefin reagent under the action of a benzoyl polymerization catalyst in a non-alcohol organic solvent under the conditions of no oxygen and stirring; carrying out a second reaction on the reaction mixture obtained in the step b) and the step a) under the action of aromatic tertiary amine under the conditions of no oxygen and stirring; c) carrying out a third reaction on the reaction mixture obtained in the step b) under the action of water and a phase transfer catalyst, and aging and replacing the obtained reaction mixture with a solvent to obtain gel; step d) carrying out carbon dioxide supercritical drying on the gel obtained in the step c). The method provided by the invention has the characteristics of simple flow, high controllable degree, high accuracy and simple and convenient operation, and the obtained shape memory aerogel has the characteristics of high porosity, low density, high shape recovery rate, glass transition temperature range of-60-180 ℃ and the like.

Description

Shape memory aerogel and preparation method thereof

Technical Field

The invention belongs to the technical field of materials, and particularly relates to a shape memory aerogel and a preparation method thereof.

Background

The aerogel is a novel light porous amorphous nano material with the smallest density in the world, the porosity is more than 98 percent, and the current lightest silicon aerogel is only 0.16mg/cm ³ . The aerogel can be divided into organic aerogel, inorganic aerogel, mixed aerogel, compound aerogel four kinds, can remove the internal solvent through the drying, can keep the shape of itself unchangeable again to the gel that reaches the effect of high porosity, low density generally all can be called the aerogel, because its have characteristics such as high porosity, low density, high specific surface area, low coefficient of thermal conductivity, the aerogel is by wide application in fields such as thermal-insulated heat preservation, absorption, energy-conservation, energy storage device and aerospace.

Along with the development and progress of science and technology, the performance of each aspect of materials is also required to be higher and higher, the research and development of intelligent materials arouses the high attention of related personnel at home and abroad, the shape memory material is a novel intelligent material with good development prospect, and can adjust mechanical parameters under the conditions of controllable external stimuli such as heat, light, water, electricity, magnetism, chemical induction and the like so as to return to the initial shape or state of the shape memory material. Currently, research on shape memory materials has focused on shape memory polymers, and shape memory polymers such as shape memory polyurethane, shape memory epoxy resin, shape memory cyanate resin, shape memory polyimide, etc. have been developed, but research on shape memory aerogels has been very rare.

The shape memory aerogel has the characteristics of high porosity and low density of the aerogel, is endowed with a shape memory function, and can change mechanical parameters (such as strain, shape, position and the like) under the external stimulation condition to generate a shape rebound effect. The shape memory aerogel is short in development time, a thesis about the shape memory aerogel appears for the first time in 2013, belongs to a frontier functional material, and is expected to be applied to the fields of aerospace, precision equipment, weaponry, textiles, medical appliances, building materials, daily necessities and the like. The prior published patents related to shape memory aerogel are few, chinese patent CN108212032A discloses a shape memory aerogel material and a preparation method thereof, but the method requires ice bath conditions for the process, the operation process is complex, the experimental repeatability and the industrial production possibility are lower, anhydrous ethanol supercritical drying is used for the patent, the drying pressure is high, the drying requirement is high, and in addition, the glass transition temperature range of the aerogel material prepared by the patent is 40-120 ℃, and the adjustable range is smaller.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a shape memory aerogel and a preparation method thereof, the preparation method of the shape memory aerogel provided by the present invention is simple, and the obtained shape memory aerogel has good high temperature resistance and thermal insulation performance, adjustable glass transition temperature, and excellent compression resilience.

The invention provides a preparation method of a shape memory aerogel, which comprises the following steps:

step a), carrying out a first reaction of a sulfydryl reagent and a double-bond-containing reagent in a non-alcohol organic solvent under the action of a polymerization catalyst under the conditions of no oxygen and stirring;

carrying out a second reaction on the reaction mixture obtained in the step b) under the action of an amine compound under the conditions of no oxygen and stirring;

c) carrying out a third reaction on the reaction mixture obtained in the step b) under the action of water and a phase transfer catalyst, and aging and replacing the obtained reaction mixture with a solvent to obtain gel;

and d), performing carbon dioxide supercritical drying on the gel obtained in the step c) to obtain the shape memory aerogel.

The method takes a sulfydryl reagent and a double bond-containing reagent as raw materials, and firstly carries out a first reaction under the conditions of non-alcohol organic solvent, benzoyl polymerization catalyst, no oxygen and stirring. In one embodiment, the mercapto agent is selected from one or more of 1, 6-hexanedithiol, isooctyl thioglycolate, mercaptopropylmethyldimethoxysilane, ethyl thioglycolate, (3-mercaptopropyl) trimethoxysilane, pentaerythritol tetrakis (3-mercaptopropionate), 3-mercapto-4-methyl-4H-1, 2, 4-triazole; in one embodiment, the mercapto agent is selected from (3-mercaptopropyl) trimethoxysilane.

In one embodiment, the double bond containing reagent is selected from one or more of triallylisocyanurate, vinyltrimethylethoxysilane or HDI trimer; in one embodiment, the double bond containing agent is selected from triallylisocyanurate or HDI trimer.

In one embodiment, the non-alcoholic organic solvent is selected from acetone or acetonitrile; in one embodiment, the non-alcoholic solvent is selected from acetone.

In one embodiment, the polymerization catalyst is selected from one or more of hydrogen peroxide, benzoyl peroxide, potassium persulfate, t-butyl peroxide, azobisisobutyronitrile and azobisisoheptonitrile; in one embodiment, the benzoyl polymerization catalyst is selected from azobisisobutyronitrile.

In one embodiment, the molar ratio of thiol in the thiol reagent to vinyl in the double bond-containing reagent is 1:1.

in one embodiment, the molar ratio of non-alcoholic organic solvent to the total of thiol reagent and double bond containing reagent is 1: (5-200); in one embodiment, the molar ratio of non-alcoholic organic solvent to the total of thiol reagent and double bond containing reagent is 1: (5 to 100).

In one embodiment, the molar ratio of polymerization catalyst to mercapto is 1: (1-100); in one embodiment, the molar ratio of polymerization catalyst to mercapto is 1: (5-80).

In one embodiment, the first reaction is carried out under the protection of argon, the reaction temperature is room temperature, and the reaction time is 10min to 80min.

In the invention, after the first reaction is finished, the obtained reaction mixture is subjected to a second reaction under the action of an amine compound and under the conditions of no oxygen and stirring. In one embodiment, the amine compound is selected from N-methylbutylamine, succinimide, butylamine, butyramide, N-methylaniline, p-ethoxyaniline, N-dimethylbutylamine or N, N-dimethylaniline. In one embodiment, the amine compound is selected from p-ethoxyaniline, N-dimethylbutylamine or N, N-dimethylaniline.

In one embodiment, in the step b), the volume ratio of the amine compound to the non-alcohol organic solvent is 1; in one embodiment, the volume ratio of the amine compound to the non-alcoholic organic solvent is 1.

In one embodiment, the second reaction is carried out under the protection of argon, the reaction temperature is room temperature, and the reaction time is 60-800 min.

In the invention, after the second reaction is finished, the obtained reaction mixture is subjected to a third reaction under the action of water and a phase transfer catalyst. In one embodiment, the phase transfer catalyst is selected from one of butyramide, tetramethylammonium hydroxide solution, N-methylaniline, aqueous NaOH solution, and aqueous ammonia solution, wherein the aqueous NaOH solution is a low concentration solution. In one embodiment, the phase transfer catalyst is selected from a NaOH solution with a mass concentration of 0.1-2% or an ammonia solution with a mass concentration of 20-30%; in one embodiment, the phase transfer catalyst is selected from a 0.5% by mass NaOH solution or a 25% by mass ammonia solution.

In one embodiment, in the step c), the volume ratio of the water to the amine compound is: 1, 0.1-10; in one embodiment, the volume ratio of the water to the amine compound is: 1, 0.5-8.

In one embodiment, the volume ratio of the phase transfer catalyst to the amine compound is 1 to 10; in one embodiment, the volume ratio of the phase transfer catalyst to the amine compound is 1.

In one embodiment, the temperature of the third reaction is room temperature, and the reaction time is 10min to 200min.

After the third reaction, the obtained reaction mixture is poured into a mold, sealed and aged. In one embodiment, the aging is carried out in an oven at a temperature of 20 to 120 ℃ for a period of 1 to 10 days. In one embodiment, the aging temperature is 30 to 100 ℃ and the aging time is 2 to 8 days.

And after the aging is finished, carrying out solvent replacement on the obtained aged gel, wherein a replacement solvent adopted by the solvent replacement is an alcohol solvent or a ketone solvent, the replacement times are 1-3 times, and the replacement time is 1-5 days.

And finally, carrying out carbon dioxide supercritical drying on the replaced gel to obtain the reticular aerogel with the shape memory characteristic. In one embodiment, the pressure of the carbon dioxide supercritical drying is 18-22 MPa, and the time is 3-5 days.

The invention also provides the shape memory aerogel prepared by the method in the technical scheme.

In one embodiment, the pore size of the shape memory aerogel is 200 to 10 ⁶ nm, porosity of 80-99%, shape recovery of 95-100%, and glass transition temperature of-60-180 deg.C.

The reticular shape memory aerogel material prepared by the invention has the performances of light weight, heat insulation, high thermal decomposition temperature, high shape memory and the like, can be used for heat insulation between an engine compartment or other easily-ignited parts and an bomb compartment, can effectively prevent heat from spreading to the bomb compartment when the engine compartment is overheated, and plays a good role in protection.

The method takes a sulfhydryl reagent and a double-bond-containing reagent as raw materials, sequentially carries out three-step reaction under the action of a benzoyl polymerization catalyst, an amine compound, water and a phase transfer catalyst under the conditions of non-alcohol organic solvent and anaerobic stirring, and leads sulfhydryl and vinyl groups to be continuously collided and polymerized through treatments of sol gelation, aging, solvent replacement, supercritical carbon dioxide drying and the like, thus forming the reticular framework aerogel with shape memory. The method provided by the invention has the advantages of simpler process, high controllable degree, high accuracy and simple and convenient operation, the obtained shape memory aerogel has the characteristics of high porosity, low density, high shape recovery rate, glass transition temperature range of-60-180 ℃ and the like, and the drying process can select the nano porous shape memory aerogel in a carbon dioxide supercritical drying mode, so that the application range of the shape memory aerogel is expanded, and the shape memory aerogel can be produced in a large scale.

In addition, the shape memory aerogel obtained by the preparation method provided by the invention has obvious macroporous structure characteristics, and the pore diameter is 10 ⁴ ～10 ⁶ The size between nm is 60%, 10% ² ～10 ⁴ The size of nm is 36%, 1-10 ² The size between nm is 4% and is 10 ⁴ ～10 ⁶ The pore diameter between nm is mainly distributed at 10 ⁴ The porosity of the material measured by mercury porosimetry is over 85 percent near nm, and the bulk density is 0.0027g/cm ³ The composite material has the advantages of good pore structure, high porosity, low density and light weight. Meanwhile, the shape memory aerogel provided by the invention has good high temperature resistance and heat insulation performance, and the glass transition temperature is adjustable. The shape memory aerogel provided by the invention has the advantages of high shape recovery rate and high recovery rate.

Compared with the traditional preparation method, the invention has the following effects:

1. compared with the existing shape memory aerogel, the preparation method disclosed by the invention has the advantages that the sulfydryl and the vinyl are selected for synthesizing the shape memory aerogel, the prepared material is non-toxic and environment-friendly, the gel structure unit prepared by the selected monomers through chemical polymerization has a good symmetrical structure, and a huge reticular molecular structure is formed in the preparation process of the shape memory material, so that the strength of the material is increased, the shape recovery rate of the material is improved, the shape memory function is better realized, the excellent cycle performance of the material compared with the existing shape memory aerogel is reflected in practical application, and the preparation method has good improvement significance on the service cycle, stability, application universality and application scene applicability of the material.

2. Different from the existing complex preparation method for further preparing the shape memory aerogel material by using the shape memory polymer or singly preparing the shape memory aerogel on the basis of the epoxy resin material, the invention can directly select different monomers to synthesize the shape memory aerogel by using a simple preparation process, has wide monomer selection range, can directly regulate and control the microscopic and macroscopic structures of the aerogel from a gel reaction monomer by changing the proportion of different sulfhydryl reagents, realizes the regulation of the glass transition temperature of the material between minus 60 ℃ and 180 ℃, can meet different requirements of different application scenes on the triggering condition of the shape memory function, and has wide application prospect.

3. Compared with the existing shape memory aerogel, the shape memory aerogel has the advantages of small volume density, light weight, unique macroporous structure and high porosity, more than 80% of the prepared aerogel is air, the prepared aerogel has the characteristic of excellent heat conductivity, the heat conductivity coefficient is as low as 0.0027W/(m.K), and the shape memory aerogel has the characteristics of obvious light weight, low load and good heat insulation effect when being used as an airborne heat insulation material, and has good performance advantages.

4. Compared with the existing shape memory aerogel, the drying process of carbon dioxide supercritical drying provided by the invention has the advantages of simpler operation process and better drying effect compared with the drying process taking absolute ethyl alcohol as a medium, and the compression resilience of the material is improved.

Drawings

Fig. 1 is a schematic view of a preparation process of a shape memory aerogel provided in an embodiment of the present invention;

FIG. 2 is a scanning electron microscope image of shape memory aerogels SMPs prepared in example 1 of the present invention at a scale of 1 μm;

FIG. 3 is a scanning electron microscope image of shape memory aerogels SMPs prepared in example 1 of the present invention at a scale of 200 nm;

FIG. 4 is a plot of the pore size distribution (mercury intrusion test) of the shape memory aerogel SMPs prepared in example 1 of the present invention;

FIG. 5 is a thermal transfer infrared thermal imager image of the shape memory aerogel prepared in example 2;

FIG. 6 is a graph of the heat transfer rate at the center point of samples of shape memory aerogels prepared in examples at different solids contents;

FIG. 7 is a thermogravimetric analysis curve of the shape memory aerogel prepared in example 2;

FIG. 8 is a thermal exploded view of shape memory aerogels prepared in examples 1 and 3 of the present invention;

FIG. 9 shows the glass transition temperature of the shape memory aerogel prepared in example 1 of the present invention;

FIG. 10 shows the glass transition temperature of the shape memory aerogel prepared in example 3 of the present invention;

fig. 11 shows the compression rebound test results of the shape memory aerogel prepared in example 3 of the present invention.

Detailed Description

The shape memory aerogel and the preparation method thereof provided by the present invention are further described with reference to the following examples.

Example 1

Referring to fig. 1, fig. 1 is a schematic view of a preparation process of a shape memory aerogel according to an embodiment of the present invention, which is to prepare a sol by using a specific raw material and method, convert the sol into a gel, and perform aging, solvent replacement, supercritical drying, and/or freeze drying to obtain a nanoporous shape memory aerogel. The specific process is as follows:

mixing 6.28g of HDI trimer and 5.889g of (3-mercaptopropyl) trimethoxysilane, adding 400ml of acetone solution into the mixed solution, rapidly adding 2.00g of azobisisoheptonitrile, filling the mixed solution into a Schlenk bottle for reaction, stirring the solution for 30min, adding 6ml of p-ethoxyaniline, stirring the solution for 4h, adding 1.62ml of water and 1ml of 25% ammonia water solution, stirring for 10min, pouring the uniform solution into a mold, sealing, and aging at 60 ℃ in a dry environment for 3 days. And after aging is finished, taking out the formed gel, performing solvent replacement by using an acetone solution for 3 days, performing carbon dioxide supercritical drying, and drying at the drying pressure of 20MP for 4 days to obtain the shape memory aerogel SMPs.

The performance of the aerogel is characterized, and the results are shown in fig. 2, fig. 3 and fig. 4, fig. 2 is a scanning electron microscope image of the shape memory aerogel SMPs prepared in example 1 of the present invention under a scale of 1 μm, fig. 3 is a scanning electron microscope image of the shape memory aerogel SMPs prepared in example 1 of the present invention under a scale of 200nm, and fig. 4 is a pore size distribution curve (mercury intrusion test) of the shape memory aerogel SMPs prepared in example 1 of the present invention, wherein fig. 4 (a) is a cumulative pore size distribution curve, and fig. 4 (b) is a pore size distribution curve (mercury intrusion test). As can be seen from FIGS. 2, 3 and 4, the macroporous structure of the shape memory aerogel SMPs prepared in example 1 is very obvious, and the pore diameter is 10 ⁴ ～10 ⁶ The size between nm is 60%, 10% ² ～10 ⁴ The size of nm is 36%, 1-10 ² The size between nm is 4% and is 10 ⁴ ～10 ⁶ The pore diameter between nm is mainly distributed at 10 ⁴ The porosity of the material measured by mercury porosimetry is over 85 percent near nm, and the bulk density is 0.0027g/cm ³ The material has good pore structure, high porosity, low density and light weight, so the material has great advantages in aviation application.

Referring to fig. 8, fig. 8 is a thermal decomposition diagram of the shape memory aerogels prepared in examples 1 and 3 of the present invention, wherein curve 1 is a graph of the sample prepared in example 1, and curve 3 is a graph of the sample prepared in example 3. As can be seen from FIG. 8, the shape memory gels prepared in examples 1 and 3 have different degrees of thermal decomposition, but the decomposition temperatures are all around 350 ℃, the different degrees of thermal decomposition are mainly due to the fact that the solvents and the polymer molecular chains selected as raw materials for preparation have different silicon contents, and the molecular weight of the polymer required for separating the acetone solvent to form stable gel is higher, so that the acetone solvent is decomposed more fully during thermal decomposition, the residual solvent is less, and the degree of thermal decomposition with higher silicon content is higher.

Referring to fig. 9, fig. 9 shows the glass transition temperature of the shape memory aerogel prepared in example 1 of the present invention, which is 73.5 ℃.

The sample prepared in example 1 was subjected to a compression rebound test, and the prepared sample was a cylinder 3cm long and 1cm in diameter. The sample is placed in a heating box and heated to 110 ℃, then the sample is compressed to 1.5cm by a clamp, the sample and the clamp are taken out together and placed at room temperature, the compressed shape can be fixed after the temperature is reduced to the room temperature, then the temperature is increased to 110 ℃, the sample returns to 2.98cm within 4 minutes and 31 seconds, and the recovery rate is as high as 99.3 percent, which shows that the material of the embodiment has rapid shape recovery rate, high recovery rate and good shape memory performance.

Example 2

Mixing 9.97g of triallyl isocyanurate and 23.56g of (3-mercaptopropyl) trimethoxysilane, adding 400ml of acetone solution into the mixed solution, quickly adding 1.28g of azobisisobutyronitrile into a Schlenk bottle for reaction, stirring the solution for 30min, adding about 6ml of N, N dimethylbutylamine, stirring the solution for 4h, adding 6.48ml of water and 1ml of 0.5% sodium hydroxide solution, stirring for 10min, pouring the uniform solution into a mold, sealing, and aging at 60 ℃ in a dry environment for 3 days. And after aging is finished, taking out the formed gel, performing solvent replacement by using an acetone solution for 3 days, performing carbon dioxide supercritical drying, and drying at the drying pressure of 20MP for 4 days to obtain the shape memory aerogel.

The aerogel was heated on a hot plate at 200 ℃ and the temperature distribution was analyzed by an infrared thermal imager, as shown in fig. 5, 6 and 7, fig. 5 being a thermal transfer infrared imager image of the shape memory aerogel prepared in example 2, wherein fig. 5 (a) is an image at 0s,27.724 ℃, fig. 5 (b) is an image at 120s,70.83 ℃, fig. 5 (c) is an image at 240s,53.481 ℃, fig. 5 (d) is an image at 360s,62.437 ℃, fig. 5 (e) is an image at 480s,65.282 ℃, fig. 6 is a graph of the heat transfer rate of the center point of the sample prepared in example, wherein curve b is a graph of the sample prepared in example 2, curve a is a graph of the heat transfer rate of the aerogel prepared in example 2, wherein curve a is a graph of the amount of triallyl isocyanurate and (3-mercaptopropyl) trimethoxysilane reduced by half on the basis of example 2, and a graph of the solid content of the aerogel prepared in example 2 is a graph of the trimethoxysilane prepared in example 2, and the solid content of the aerogel prepared in example 2 is doubled on the basis of example 2, and the thermogravimetric analysis is a graph of the solid content of the example 2. As can be seen from FIG. 5, the material has a central temperature of only about 65 ℃ and a lower surface temperature after 8 min; as can be seen from FIG. 6, the heat transfer rate is as low as 0.07 ℃/min, the temperature is almost kept stable at about 65 ℃ after the material is heated for 6min, the central temperature is only 70 ℃ after the material is heated for 4min, the temperature rise rate of the material is small, and the material has good high temperature resistance and heat insulation performance compared with most aerogel materials; as can be seen from FIG. 7, the thermal decomposition temperature of the material is 243 ℃, first and second pyrolysis peaks appear at 371 ℃ and 451.87 ℃ respectively, which indicates that the material has large thermal decomposition, and the material of the invention has better high temperature resistance and heat insulation performance in the organic aerogel.

The sample prepared in example 2 was subjected to a compression spring back test, the prepared sample was a 2.5cm long cylinder with a diameter of 1cm, the sample was placed in a heating box and heated to 105 ℃ and then compressed to 1.25cm with a clamp, the sample and the clamp were taken out together and placed at room temperature, the compressed shape could be fixed after the temperature was reduced to room temperature, and after the temperature was increased to 105 ℃, the sample recovered to 2.48cm within 3 minutes and 49 seconds, with a recovery rate as high as 99.2%, indicating that the material of this example had a fast shape recovery rate, a high recovery rate, and good shape memory performance.

Example 3

Mixing 9.97g of triallyl isocyanurate with 23.56g of (3-mercaptopropyl) trimethoxysilane, adding 300ml of acetone solution into the mixed solution, quickly adding 1.28g of azobisisobutyronitrile into a Schlenk bottle for reaction, stirring the solution for 40min, adding about 5ml of N, N-dimethylaniline into the solution, stirring the solution for 4h, adding 6.48ml of water and 2ml of 0.5% sodium hydroxide solution, stirring the solution for 10min, pouring the uniform solution into a mold for sealing, and aging the uniform solution at the dry environment of 60 ℃ for 3 days. And after aging is finished, taking out the formed gel, performing solvent replacement by using an acetone solution for 3 days, performing carbon dioxide supercritical drying, and drying at the drying pressure of 20MP for 4 days to obtain the shape memory aerogel.

Referring to fig. 8, fig. 8 is a thermal decomposition diagram of the shape memory aerogels prepared in examples 1 and 3 of the present invention, wherein curve 1 is a graph of the sample prepared in example 1, and curve 3 is a graph of the sample prepared in example 3. It can be seen from fig. 8 that the shape memory gels prepared in examples 1 and 3 have different degrees of thermal decomposition, but the decomposition temperatures are all around 350 ℃, the difference in the degree of thermal decomposition is mainly due to the fact that the solvents and polymer molecular chains selected as raw materials for preparation have different silicon contents, and the molecular weight of the polymer required for separating the acetone solvent to form a stable gel is higher, so that the decomposition is more complete during thermal decomposition, the remaining solvents are less, and the degree of thermal decomposition with higher silicon content is higher. Referring to fig. 10, fig. 10 shows the glass transition temperature of the shape memory aerogel prepared in example 3 of the present invention, which is 185 ℃.

The compression rebound test is performed on the sample prepared in example 3, and the result is shown in fig. 11, and fig. 11 is a compression rebound test result of the shape memory aerogel prepared in example 3 of the present invention, the prepared sample is a cylinder with a length of 2.5cm and a diameter of 1cm, the sample is placed in a heating box, heated to 195 ℃, compressed to 1.25cm by a clamp, the sample and the clamp are taken out together, the compressed shape can be fixed at room temperature after the temperature is reduced to room temperature, and then the sample returns to 2.48cm within 7 minutes and 43 seconds after the temperature is increased to 195 ℃, and the recovery rate is as high as 99.2%.

The analysis can be integrated to obtain that the material has the characteristics of high porosity, low density, high temperature resistance, good heat insulation performance, adjustable glass transition temperature and excellent compression resilience, so that the shape memory aerogel prepared by the invention can be well used as an advanced heat insulation material between an aircraft engine cabin and a bomb cabin, and can also be applied to other aspects according to requirements.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. A preparation method of shape memory aerogel comprises the following steps:

mixing 6.28g of HDI tripolymer and 5.889g of (3-mercaptopropyl) trimethoxysilane, adding 400ml of acetone solution into the mixed solution, adding 2.00g of azobisisoheptonitrile, putting into a Schlenk bottle for reaction, stirring the solution for 30min, adding 6ml of p-ethoxyaniline, stirring the solution for 4h, adding 1.62ml of water and 1ml of 25% ammonia water solution, stirring for 10min, pouring the uniform solution into a mold, sealing, aging at 60 ℃ in a drying environment for 3 days, taking out the formed gel after aging, performing solvent replacement by using acetone solution, performing replacement for 3 days, performing carbon dioxide supercritical drying, and drying at the drying pressure of 20MPa for 4 days to obtain shape memory aerogel SMPs;

or comprises the following steps:

mixing 9.97g of triallyl isocyanurate and 23.56g of (3-mercaptopropyl) trimethoxysilane, adding 400ml of acetone solution into the mixed solution, adding 1.28g of azobisisobutyronitrile into a Schlenk bottle for reaction, stirring the solution for 30min, adding 6ml of N, N-dimethylbutylamine, stirring the solution for 4h, adding 6.48ml of water and 1ml of 0.5% sodium hydroxide solution, stirring for 10min, pouring the uniform solution into a mold, sealing, aging at 60 ℃ in a drying environment for 3 days, taking out the formed gel after aging, performing solvent replacement by using acetone solution for 3 days, performing carbon dioxide supercritical drying, and drying at 20MPa for 4 days to obtain the shape memory aerogel;

or comprises the following steps:

mixing 9.97g of triallyl isocyanurate and 23.56g of (3-mercaptopropyl) trimethoxysilane, adding 300ml of acetone solution into the mixed solution, adding 1.28g of azobisisobutyronitrile into a Schlenk bottle for reaction, stirring the solution for 40min, adding 5ml of N, N-dimethylaniline into the solution, stirring the solution for 4h, adding 6.48ml of water and 2ml of 0.5% sodium hydroxide solution, stirring the solution for 10min, pouring the uniform solution into a mold for sealing, aging the uniform solution at 60 ℃ for 3 days, taking out the formed gel after aging, performing solvent replacement by using acetone solution for 3 days, performing carbon dioxide supercritical drying, and performing drying at the drying pressure of 20MPa for 4 days to obtain the shape memory aerogel.