TEP / TEP-PEG bidirectional responsive shape memory composite film and preparation method thereof

Abstract

The present application relates to a kind of TEP / TEP-PEG bidirectional response shape memory composite film and its preparation method.The present application is with two-component TEP, PEG, accelerator as raw material, by the melting-dispersion technology of PEG, the polymerization-hardening forming technology of TEP and pre-stretching-laminating technology development TEP / TEP-PEG bidirectional response shape memory composite film.The composite film is with TEP as composite film passive layer, with high storage modulus and high T g , with TEP / PEG as composite film active layer, with low storage modulus and low T g . Through the coupling of double-layer structure, TEP / TEP-PEG composite film can produce shape change by responding temperature stimulus, realizes the bidirectional controllable intelligent response of temperature stimulus in single heating process.The composite film also has the function of repairable, recyclable-rework, and shows application potential in the field of flexible actuator and intelligent unit structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of shape memory materials, and relates to a repairable, recyclable and reworkable TEP / TEP-PEG bidirectional response shape memory composite film with thermoplastic epoxy resin (TEP) as a passive layer and TEP / polyethylene glycol (PEG) as an active layer and a preparation method thereof. BACKGROUND

[0002] Epoxy resin is a high-performance polymer material containing epoxy groups, which is generally a low-viscosity liquid before hardening and can be hardened and shaped through ring-opening reaction of epoxy groups. Common epoxy resins are mostly thermosetting materials with cross-linked structures, which have high mechanical strength, high durability, good high-temperature resistance and chemical corrosion resistance, and can be widely applied to structural parts, coatings and adhesives, etc. The low-viscosity state of epoxy resin before hardening makes it easy to process and shape, and can meet the requirements of various complex shapes and sizes, and is often used as a matrix of composite systems in the field of composite materials.

[0003] Although epoxy resin itself has many advantages, its thermosetting property makes it prone to loss under high temperature conditions, and it also has the disadvantages of low recycling rate, poor reworkability and environmental pollution, which greatly limits its application. Compared with thermosetting resin materials, thermoplastic resin has the advantages of recyclability, superior processing performance, strong plasticity and solubility, etc., making it more competitive in some more environmentally friendly application fields. As an emerging functional polymer material, TEP has the advantages of plasticity and multiple processing, which makes it have advantages in meeting the individualized needs of products. However, most of the reported epoxy resins are thermosetting, and there are few reports on TEP, and its performance research and application development need to be carried out.

[0004] Epoxy resin before hardening is usually in a low molecular state, which is beneficial to its modification by melt dispersion and solvent dispersion. In recent years, dispersing organic and inorganic modifiers in the liquid matrix of epoxy resin before hardening has become an effective way to modify epoxy resin. As an important plasticizer, PEG is often used to improve the thermal and mechanical properties of polymers. The compatibility of PEG with polymers is an important factor affecting the uniformity of the composite system. It is worth noting that PEG has good compatibility with many polymers and is relatively low in cost. It has been reported that by adding PEG in epoxy resin before cross-linking and then using the curing of epoxy resin, a stable epoxy resin-plasticizer composite system can be formed, which can achieve the effect of plasticizing thermosetting epoxy resin.

[0005] As a kind of smart materials, shape memory materials can dynamically switch between original shape and temporary shape through external stimuli such as temperature, light, electricity and humidity, and can perform specific functions during shape switching, playing a role in medical devices, intelligent structures, electronic devices and other fields. Among them, shape memory epoxy resin has become a material of great attention in the fields of medical devices, intelligent structure manufacturing, aerospace and self-repairing due to its excellent mechanical properties, adhesion, heat resistance and chemical resistance. It is reported that by controlling and adjusting the shape memory effect of epoxy resin, highly controllable shape change function can be achieved, and shape memory effect occurs within a specific temperature range. Because shape memory epoxy resin is mostly thermosetting, its three-dimensional network molecular chain structure has low deformation ability, which has the disadvantage of irreversibility, which to some extent limits its application range. Unlike thermosetting shape memory polymers, thermoplastic shape memory polymers have higher deformation rate and faster recovery speed due to their linear molecular chain structure, which makes thermoplastic shape memory polymers have wide application potential in many fields. Therefore, research on shape memory TEP needs to be carried out, especially in more environmentally friendly fields.

[0006] Although shape memory polymers show great application potential, the development of high-performance bidirectional response shape polymers and their multifunctionalization are still research difficulties. Traditional unidirectional shape polymers cannot recover their temporary shape after completely recovering their original shape. Compared with traditional unidirectional shape polymers, bidirectional shape polymers not only can recover from temporary shape to original shape, but also can deform from original shape to temporary shape under non-mechanical stimuli such as temperature, light and humidity. In recent years, due to the intelligent switching between original shape and temporary shape, bidirectional shape polymers have shown considerable application prospects in artificial intelligence, bionics and medical fields. Compared with traditional unidirectional shape polymers, bidirectional shape memory polymers require more stringent stimulation conditions. In terms of temperature stimulation of bidirectional shape memory polymers, the original shape and temporary shape of bidirectional shape polymers are generally regulated by heating and cooling, but the research on shape switching of bidirectional shape polymers during continuous heating process is rarely reported. SUMMARY

[0007] The purpose of the present application is to prepare a TEP / TEP-PEG bidirectional response shape memory composite film, which has a TEP / TEP-PEG bidirectional response shape memory function of repairable, recyclable-reworkable and temperature-stimulable, and the bidirectional response of TEP / TEP-PEG is realized in a single heating process.

[0008] The present application starts from three aspects of the melt dispersion of PEG, the polymerization reaction of TEP and the lamination of double-layer film, explores the correlation rules between the controllable preparation, structure design and shape memory effect of the TEP / TEP-PEG bidirectional response shape memory composite film. Through the melt-dispersion technology of PEG, the polymerization-hardening forming technology of TEP and the pre-stretching-lamination technology, the TEP / TEP-PEG bidirectional response shape memory composite film is finally developed.

[0009] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0010] The TEP / TEP-PEG bidirectional response shape memory composite film is composed of a TEP film and a TEP-PEG film, and the mass ratio of TEP to PEG in the TEP-PEG film is 10:(2.5-4); wherein the thermoplastic epoxy resin (TEP) film is the passive layer of the TEP / TEP-PEG bidirectional response shape memory composite film, and the PEG modified thermoplastic epoxy resin (TEP-PEG) film is the active layer of the TEP / TEP-PEG bidirectional response shape memory composite film.

[0011] The present application also provides a preparation method of the TEP / TEP-PEG bidirectional response shape memory composite film, which comprises the following steps:

[0012] (1) adding a promoter into the TEP melt, then performing hot pressing in a hot press at a certain temperature, increasing the pressure once every certain time, obtaining the TEP film after hot pressing for a certain time, and then transferring to room temperature for cooling to obtain the hardened and formed TEP film;

[0013] (2) adding PEG into the TEP melt, heating and stirring until the mixed melt is transparent, then adding a promoter, stirring uniformly to obtain a TEP-PEG prepolymer mixture, transferring to a hot press at a certain temperature for hot pressing, increasing the pressure once every certain time, obtaining the TEP-PEG film after hot pressing for a certain time, and then transferring to room temperature for cooling to obtain the hardened and formed TEP-PEG film;

[0014] (3) cutting the hardened and formed TEP-PEG film obtained in step (2) according to a certain size, preheating and stretching in a glass transition temperature (T g ) environment, and then quickly placing it below T g for cold setting; the obtained cold set TEP-PEG film is uniformly coated with tetrahydrofuran (THF), and then quickly combined with the TEP film obtained in step (1) to obtain a TEP-PEG and TEP combined double-layer film, and the obtained double-layer film is pressed with a metal plate for a certain time to obtain the TEP / TEP-PEG bidirectional response shape memory composite film.

[0015] Further, the preparation method of the TEP melt is as follows: the TEP is placed in a heating instrument, heated and stirred at 110℃ and a stirring speed of 300r / min for 5min to obtain a transparent TEP melt before polymerization.

[0016] Further, the operation of the hot pressing in step (1) is as follows: the temperature of the hot press is set to 150℃, the initial pressure is set to 1MPa, and timing is 5min; then the pressure is set to 5MPa, and timing is 10min; then the pressure is set to 20MPa, and finally timing is 20min.

[0017] Further, the accelerator in step (1) is an amine accelerator, and the addition amount of the accelerator is 3% of the mass of the TEP melt.

[0018] Further, the mass ratio of the TEP to the PEG in step (2) is 10:(2.5-4), preferably 10:3; the temperature of the heating and stirring is 85℃, the stirring speed is 300r / min, the accelerator is an amine accelerator, and the mass ratio of the TEP to the accelerator is 100:3.

[0019] Further, the operation of the hot pressing in step (2) is as follows: the temperature of the hot press is set to 150℃, the initial pressure is set to 1MPa, and timing is 5min; then the pressure is set to 2MPa, and timing is 10min; then the pressure is set to 4MPa, and finally timing is 20min.

[0020] Further, the stretching rate of the preheating stretching in step (3) is 25%, and the pressing time of the double-layer film with the metal plate is 10min.

[0021] The TEP / TEP-PEG bidirectional shape memory composite film provided by the application has the advantages of bidirectional response, temperature stimulation, repairability, recyclability and reworkability, etc.

[0022] Compared with the existing shape memory polymer materials and the preparation methods thereof, the application has the following beneficial effects:

[0023] (1) The materials used in the present application are all high molecular materials, and the prepared TEP / TEP-PEG bidirectional shape memory composite film has the advantages of light weight and low cost.

[0024] (2) The present application realizes the repairable function of the active layer (TEP-PEG) of the TEP / TEP-PEG bidirectional shape memory composite film by using the active molecular thermal motion of PEG in the heating process.

[0025] (3) The present application realizes the melting recycling-reprocessing function and the environmental protection advantage of the TEP / TEP-PEG bidirectional shape memory composite film by using the thermoplasticity of the selected TEP and the regulation effect of PEG on the thermal performance of the composite system.

[0026] (4) The present application realizes the bidirectional response shape memory function of the TEP / TEP-PEG composite film by using the preheating stretching of the active layer (TEP-PEG) and the lamination with the passive layer (TEP).

[0027] (5) The present application realizes the bidirectional response shape memory function of the TEP / TEP-PEG composite film in a single heating process by using the thermal recovery of the preheating stretched active layer (TEP-PEG) and the regulation effect of PEG on its viscoelasticity. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 TEP-PEG film preparation process.

[0029] Figure 2 TEP-PEG30 film one-way shape memory process.

[0030] Figure 3 TEP-PEG film stretching mode one-way shape memory mechanism.

[0031] Figure 4 TEP-PEG30 film stretching mode one-way shape memory curve.

[0032] Figure 5 TEP-PEG film and TEP film composite process.

[0033] Figure 6 TEP / TEP-PEG film bidirectional shape memory mechanism.

[0034] Figure 7 Active layer (TEP-PEG30) storage modulus, loss modulus and Tan delta curve.

[0035] Figure 8 Passive layer (TEP) storage modulus, loss modulus and Tan delta curve.

[0036] Figure 9Shape memory results for TEP / TEP-PEG30 films.

[0037] Figure 10 Shape memory results for TEP / TEP-PEG films.

[0038] Figure 11 Repairable, recyclable-reworkable process for TEP / TEP-PEG films.

[0039] Figure 12 TEM photos of TEP / TEP-PEG films after repair. DETAILED DESCRIPTION

[0040] The application will be further described below in connection with specific examples. It should be understood that the following examples are intended to illustrate the application and are not intended to limit the scope of the application. Those skilled in the art can make some non-essential improvements and adjustments to the application according to the above content.

[0041] Example 1

[0042] The preparation method of the TEP / TEP-PEG bidirectional shape memory composite film in this example is as follows:

[0043] 1) 10 g of TEP (Nagase Chemical Industry Co. Ltd.) before polymerization was weighed in a beaker and placed in a heating instrument, the temperature was set to 110°C, the rotation speed was set to 300 r / min, and the TEP melt before polymerization in a transparent state was obtained after stirring for about 5 min; 0.3 g of accelerator was added to the TEP melt, and then the obtained melt was transferred to a hot press for hot pressing; the initial temperature of the hot press was set to 150°C, the initial pressure was set to 1 MPa, and the time was counted for 5 min; then the pressure was set to 5 MPa, and the time was counted for 10 min; then the pressure was set to 20 MPa, and finally the time was counted for 20 min; the obtained TEP film was transferred to room temperature for cooling, and a hardened TEP film was obtained;

[0044] 2) Weigh 10 g of TEP (Nagase Chemical Industry Co. Ltd.) before polymerization in a beaker, and place it in a heating instrument, set the temperature to 110°C, and the rotation speed to 300 r / min, stir for about 5 min, to obtain a transparent TEP melt before polymerization; add 2.5 g of PEG to the obtained melt, continue heating and stirring until the mixed melt is transparent; add 0.3 g of amine type accelerator (aromatic phosphate) to the obtained mixed melt, stir until uniform, to obtain a TEP-PEG prepolymer mixture; transfer the obtained TEP-PEG prepolymer mixture to a hot press for hot pressing; set the initial temperature of the hot press to 150°C, and the initial pressure to 1 MPa, and time for 5 min; then set the pressure to 2 MPa, and time for 10 min; then set the pressure to 4 MPa, and finally time for 20 min; transfer the obtained TEP-PEG film to room temperature for cooling, to obtain a hardened shaped TEP-PEG film;

[0045] 3) Cut the hardened shaped TEP-PEG film obtained in step (2) to a certain size; preheat stretch the cut TEP-PEG film at its glass transition temperature (40°C) environment, with a stretching rate of 25%, and then quickly place it in a T g emperature below for cold setting; uniformly coat the obtained cold set TEP-PEG film with THF, and then quickly laminate it with a TEP film of the same size; press the obtained TEP / TEP-PEG 25 bidirectional shape memory composite film with a 2.4 kg metal plate for 10 min.

[0046] Example 2

[0047] The preparation method of the TEP / TEP-PEG bidirectional shape memory composite film of this example is as follows:

[0048] 1) Same as Example 1.

[0049] 2) Take 10 g of TEP (Nagase Chemical Industry Co. Ltd.) before polymerization with a beaker, place it in a heating instrument, set the temperature to 110°C, set the rotation speed to 300 r / min, stir for about 5 min, and obtain a transparent TEP melt before polymerization; add 3.0 g of PEG to the obtained melt, continue to heat and stir until the mixed melt is transparent; add 0.3 g of amine type accelerator (aromatic phosphate) to the obtained mixed melt, stir uniformly to obtain a TEP-PEG prepolymer mixture; transfer the obtained TEP-PEG prepolymer mixture to a hot press for hot pressing; set the initial temperature of the hot press to 150°C, set the initial pressure to 1 MPa, and time for 5 min; then set the pressure to 2 MPa, time for 10 min; then set the pressure to 4 MPa, and finally time for 20 min; transfer the obtained TEP-PEG film to room temperature for cooling, and obtain a hardened and shaped TEP-PEG film;

[0050] 3) Cut the obtained hardened and shaped TEP-PEG film according to a certain size; preheat and stretch the obtained cut TEP-PEG film at its glass transition temperature (35°C) environment, the stretching rate is 25%, and then quickly place it in a T g temperature below for cold setting; uniformly coat the obtained cold set TEP-PEG film with THF, and then quickly stack it with a TEP film of the same size; press the obtained TEP / TEP-PEG30 bimorph shape memory composite film with a 2.4 kg metal plate for 10 min to obtain a TEP / TEP-PEG30 bimorph shape memory composite film.

[0051] Example 3

[0052] The preparation method of the TEP / TEP-PEG bimorph shape memory composite film in this example is as follows:

[0053] 1) Take 10 g of TEP (Nagase Chemical Industry Co. Ltd.) before polymerization with a beaker, place it in a heating instrument, set the temperature to 110°C, set the rotation speed to 300 r / min, stir for about 5 min, and obtain a transparent TEP melt before polymerization; transfer the obtained melt to a hot press at 90°C for hot pressing, increase the pressure once every certain time, and obtain a TEP film after hot pressing for a certain time; transfer the obtained TEP film to room temperature for cooling, and obtain a hardened and shaped TEP film;

[0054] 2) 10 g of TEP (Nagase Chemical Industry Co. Ltd.) before polymerization is weighed in a beaker and placed in a heating instrument, the temperature is set to 110°C, the rotation speed is set to 300 r / min, and the mixture is stirred for about 5 min to obtain a transparent TEP melt before polymerization; 4.0 g of PEG is added to the melt obtained in step 1), and the mixture is continuously heated and stirred until the mixed melt is transparent; 0.3 g of amine accelerant (aromatic phosphate) is added to the obtained mixed melt, and the mixture is uniformly stirred to obtain a TEP-PEG prepolymer mixture; the obtained TEP-PEG prepolymer mixture is transferred to a hot press for hot pressing; the initial temperature of the hot press is set to 150°C, the initial pressure is set to 1 MPa, and the time is set to 5 min; then the pressure is set to 2 MPa, and the time is set to 10 min; then the pressure is set to 4 MPa, and the time is set to 20 min; the obtained film is transferred to room temperature for cooling to obtain a hardened TEP-PEG film;

[0055] 3) The hardened TEP-PEG film obtained in step 7) is cut into a certain size; the obtained cut TEP-PEG film is preheated and stretched in a glass transition temperature (30°C) environment, and then quickly placed in a T g e below for cold setting; the obtained cold-set TEP-PEG film is uniformly coated with THF, and then quickly combined with a TEP film of the same size; the obtained TEP-PEG / TEP double-layer film is pressed with a 2.4 kg metal plate for 10 min to obtain a TEP / TEP-PEG40 bidirectional shape memory composite film.

[0056] The preparation process of the TEP-PEG film of the present application is shown in Figure 1 In the initial state of the TEP-PEG film, the shape of the TEP-PEG film is changed by heating and folding, and then the TEP-PEG film is quickly cooled to fix the temporary shape. The one-way shape memory function of the TEP-PEG film in the temporary shape is investigated by increasing the temperature. When the temperature is increased to the T g g of the TEP-PEG film, the TEP-PEG film macroscopically exhibits shape recovery, i.e., returns to the initial state, due to the induction of the internal stress generated in the previous thermal deformation and the internal molecular thermal motion of the TEP-PEG film. Figure 2 The one-way shape memory process of the TEP-PEG30 film is shown. In addition, the present application also shows the one-way shape memory mechanism of the TEP-PEG30 film in the stretching mode Figure 3 ) and the one-way shape memory test curve Figure 4 ).

[0057] Based on the shape memory research of monolayer TEP-PEG films, this invention combines a preheated, stretched, and shaped TEP-PEG film with a TEP film using a lamination technique to obtain a TEP / TEP-PEG bilayer composite film. Figure 5 The specific process is as follows: First, the TEP-PEG membrane is cut into strips of uniform size, and then... g Preheating and stretching were performed in a temperature atmosphere of approximately 25%; after pre-stretching, the material was quickly placed in a T... g The shape is fixed below the temperature. After being fixed into a temporary shape, THF is applied to the surface of a TEP membrane of the same size by dot coating. Then, the temporary TEP-PEG membrane and the TEP membrane are laminated together. Finally, a 2.4 kg metal plate is pressed for a certain period of time to obtain a T / TP double-layer composite membrane.

[0058] The bidirectional shape memory function of the TEP / TEP-PEG composite film was investigated during a continuous heating process within the range of 25℃-45℃. As the temperature gradually increased to the T0 of the active layer (TEP-PEG), the bidirectional shape memory function was further investigated. g During the initial heating and stretching process, the active layer tends to shrink in the opposite direction of the initial heating and stretching due to internal molecular thermal motion and the internal stress generated during the previous heating and stretching. This causes the TEP / TEP-PEG bilayer composite film to bend towards the active layer under the combined effect of the active layer's shrinkage and the passive layer's (TEP) restraint. As the temperature continues to rise, the storage modulus of the active layer decreases significantly due to the increasingly intense internal molecular thermal motion. This causes the passive layer, with its significantly higher storage modulus, to change from passive bending to active recovery. Ultimately, the TEP / TEP-PEG composite film exhibits shape recovery on a macroscopic scale, meaning it returns to its initial shape. At this point, rapid cooling is used to fix the shape of the TEP / TEP-PEG composite film. To initiate the next cycle of bidirectional shape memory response, simply repeat the above steps. Figure 6 The developed T / TP composite membrane exhibited excellent bidirectional shape memory function during a single heating process. Temperature-storage modulus curves and temperature-T values ​​for the active and passive layers are shown. g Curves and temperature-loss modulus curves, such as Figure 7 and Figure 8 As shown. Figure 9 The TEP / TEP-PEG30 membrane exhibits a bidirectional responsive shape memory process. As the temperature rises, when it reaches approximately 30°C, the TEP / TEP-PEG composite membrane gradually becomes flexed, and there is no significant change during the temperature rise from 30°C to 35°C. With continued heating, when the temperature reaches approximately 40°C, the TEP / TEP-PEG composite membrane gradually recovers from its flexed state, returning to its initial shape during the temperature rise from 40°C to 45°C.

[0059] The bending angle and recovery angle of the material in the experiment process are measured and counted, the bending angle and time, the recovery angle and time of the TEP / TEP-PEG composite film in the temperature increasing process in the range of 25-45 DEG C are as follows Figure 10 and shown in Table 1.

[0060] Table 1: Statistics of bending angle and recovery angle of TEP / TEP-PEG composite film

[0061]

[0062] The materials selected by the present application are all thermoplastic, having the advantages of melt recovery and reprocessing. Figure 11 The investigation process of the TEP / TEP-PEG composite film active layer (TEP-PEG) repair and recovery-reprocessing is shown, the TEP-PEG film shows the repairable function in the temperature atmosphere of 45 DEG C, and shows the melt recovery and reprocessing function in the temperature atmosphere of 90 DEG C. Figure 12 The electron microscope photos of the wound part of the TEP-PEG film after repair are shown, wherein the wound part of the TEP-PEG film shows larger healing effect after repair under the temperature condition of 45 DEG C.

[0063] The present application utilizes the thermoplasticity of TEP and the regulating effect of PEG on the thermal performance of TEP, and develops the TEP / TEP-PEG bidirectional response shape memory composite film which is repairable, recyclable-reprocessable and temperature-stimulable through three technologies of PEG melt dispersion technology, in-situ polymerization technology and lamination technology. Through the structure design, the TEP / TEP-PEG composite film can show the bidirectional shape memory response function in the temperature increasing process, and shows the considerable application prospect due to its light weight, low cost, repairability and recyclable-reprocessability, especially in the fields of flexible actuators, intelligent unit structures and intelligent structural parts.

[0064] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A TEP / TEP-PEG bidirectional responsive shape memory composite film, characterized in that: The thermoplastic epoxy resin (TEP) film and the PEG modified thermoplastic epoxy resin (TEP-PEG) film are compounded, and the mass ratio of TEP to PEG in the TEP-PEG film is 10: (2.5-4); The preparation method of the TEP / TEP-PEG bidirectional response shape memory composite film comprises the following steps: (1) adding a promoter to the TEP melt, then hot pressing in a hot press at a certain temperature, increasing the pressure every certain time, obtaining the TEP film after hot pressing for a certain time, and then transferring to room temperature for cooling to obtain the hardened TEP film; (2) adding PEG to the TEP melt, heating and stirring until the mixed melt is transparent, then adding a promoter, stirring uniformly to obtain a TEP-PEG prepolymer mixture, transferring to a hot press at a certain temperature for hot pressing, increasing the pressure every certain time, obtaining the TEP-PEG film after hot pressing for a certain time, and then transferring to room temperature for cooling to obtain the hardened TEP-PEG film; (3) cutting the hardened TEP-PEG film obtained in step (2) to a certain size, preheating and stretching in a glass transition temperature (Tg) environment, then quickly placing it below the Tg temperature for cold setting; the obtained cold set TEP-PEG film is uniformly coated with tetrahydrofuran (THF), and then quickly stacked with the TEP film obtained in step (1) to obtain a TEP-PEG / TEP stacked double-layer film, and the obtained double-layer film is pressed with a metal plate for a certain time to obtain the TEP / TEP-PEG bidirectional response shape memory composite film.

2. The method for preparing the TEP / TEP-PEG bidirectional responsive shape memory composite film according to claim 1, characterized in that... The preparation method of the TEP / TEP-PEG bidirectional response shape memory composite film comprises the following steps: (1) adding a promoter to the TEP melt, then hot pressing in a hot press at a certain temperature, increasing the pressure every certain time, obtaining the TEP film after hot pressing for a certain time, and then transferring to room temperature for cooling to obtain the hardened TEP film; (2) adding PEG to the TEP melt, heating and stirring until the mixed melt is transparent, then adding a promoter, stirring uniformly to obtain a TEP-PEG prepolymer mixture, transferring to a hot press at a certain temperature for hot pressing, increasing the pressure every certain time, obtaining the TEP-PEG film after hot pressing for a certain time, and then transferring to room temperature for cooling to obtain the hardened TEP-PEG film; (3) cutting the hardened TEP-PEG film obtained in step (2) to a certain size, preheating and stretching in a glass transition temperature (Tg) environment, then quickly placing it below the Tg temperature for cold setting; the obtained cold set TEP-PEG film is uniformly coated with tetrahydrofuran (THF), and then quickly stacked with the TEP film obtained in step (1) to obtain a TEP-PEG / TEP stacked double-layer film, and the obtained double-layer film is pressed with a metal plate for a certain time to obtain the TEP / TEP-PEG bidirectional response shape memory composite film.

3. The method for preparing the TEP / TEP-PEG bidirectional responsive shape memory composite film according to claim 2, characterized in that, The preparation method of the TEP melt is that the TEP is placed in a heating instrument, heated and stirred at 110℃ and a stirring speed of 300r / min for 5min to obtain a transparent TEP melt before polymerization.

4. The method of claim 2, wherein the TEP / TEP-PEG bi-directional responsive shape memory composite film is prepared by the steps of: The operation of the hot pressing in step (1) is as follows: the temperature of the hot press is set to 150℃, the initial pressure is set to 1MPa, and timing is 5min; then the pressure is set to 5MPa, and timing is 10min; then the pressure is set to 20MPa, and finally timing is 20min.

5. The method for preparing the TEP / TEP-PEG bidirectional responsive shape memory composite film according to claim 2, characterized in that, The accelerator used in step (1) is an amine accelerator, and the addition amount of the accelerator is 3% of the mass of the TEP melt.

6. The method for preparing the TEP / TEP-PEG bidirectional responsive shape memory composite film according to claim 2, characterized in that, In step (2), the mass ratio of TEP to PEG is 10:(2.5-4), the temperature of heating and stirring is 85℃, the stirring speed is 300r / min, the accelerator is an amine accelerator, and the mass ratio of TEP to accelerator is 100:

3.

7. The method for preparing the TEP / TEP-PEG bidirectional responsive shape memory composite film according to claim 2, characterized in that, The operation of the hot pressing in step (2) is as follows: the temperature of the hot press is set to 150℃, the initial pressure is set to 1MPa, and timing is 5min; then the pressure is set to 2MPa, and timing is 10min; then the pressure is set to 4MPa, and finally timing is 20min.

8. The method for preparing the TEP / TEP-PEG bidirectional responsive shape memory composite film according to claim 2, characterized in that, In step (3), the stretching rate of the preheating stretching is 25%, and the pressing time of the double-layer film with a metal plate is 10min.

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