Mechanically interlocked polymer networks with photoresponsiveness and preparation methods and applications thereof

Abstract

The present invention discloses a photoresponsive mechanically interlocked polymer network, a preparation method thereof, and its application in photosensitive materials. The photoresponsive mechanically interlocked polymer network is obtained by reacting raw materials including an azo monomer, polytetrahydrofuran, isophorone diisocyanate, and a pseudorotaxane monomer. The structure of the azo monomer is shown below: The specific structure of the pseudorotaxane monomer is shown below:

Description

Technical Field

[0001] The present invention relates to the field of intelligent responsive optical materials, and in particular to a mechanically interlocked polymer network with light responsiveness, a preparation method thereof, and applications thereof. Background Art

[0002] Mechanically interlocked polymer networks (MIPs) are a fusion of polymer science and mechanically interlocked structures, representing one of the latest research directions in polymer materials. MIPs combine the dynamic properties of supramolecular polymers with the stability of covalent polymers. Furthermore, the molecular-scale microscopic motions of MIPs, such as the sliding and rotation of rotaxanes, can accumulate and amplify within the polymer, endowing the polymer with unique macroscopic properties. While MIPs have been extensively studied, reports on photoresponsive MIPs are limited, and existing synthesis methods are relatively complex.

[0003] Patent specification with publication number CN115403797A discloses a sliding-ring supramolecular gel film with fast light response performance and its preparation method. The preparation method uses acrylamide functionalized with azobenzene and benzyl isocyanate and acrylamide functionalized with β-cyclodextrin as reactive monomers, forms a sliding host-guest cross-linked structure through pre-inclusion of azobenzene and cyclodextrin, and uses potassium persulfate to initiate free radical polymerization to form a supramolecular polymer. Finally, the resulting polymer is precipitated with acetone, washed, and fully swollen, spread, and dried in water to obtain a gel film. The gel film has fast light response performance. Under 365nm light, it can quickly bend up to 40° in the direction of the light source within 0.5s, and can achieve film flipping and other movements under ultraviolet light. It also has a high tensile strength of 15MPa, an elongation at break of 150%, and a Young's modulus of 0.34MPa. The patent specification with publication number CN118063716A discloses a fatigue-resistant mechanically interlocked photoresponsive supramolecular hydrogel and its preparation method. The preparation method uses (E')-N-(4-(4-(4-hydroxyazobenzene)butoxy)benzyl)acrylamide-functionalized cyclodextrin as a reactive monomer, forms a mechanically interlocked cross-linked structure by pre-encapsulation of azobenzene and cyclodextrin, and then uses potassium persulfate to initiate free radical polymerization, which is copolymerized with acrylamide to form a mechanically interlocked supramolecular hydrogel. The hydrogel has rapid photoresponsiveness and can bend rapidly by 15° toward the light source within 2 seconds under irradiation of 365nm; it also has a tensile strength of 722kPa and an elongation at break of 544%; under a tensile strain of 400%, its cyclic tensile stress remains stable after 30 cycles of stretching.

[0004] While these studies have explored the effects of azobenzene incorporation on the mechanical properties of mechanically interlocked polymers, they have not delved into the impact of the cis- and trans-isomerization of azobenzene on the mechanical properties of the mechanically interlocked polymer network. Due to the highly reversible nature of the cis / trans photoswitch, azobenzene-based photoresponsive materials have applications in toughening agents, energy storage systems, switchable catalysis, controlled release, and photopharmacology.

[0005] The applicant previously disclosed a photoresponsive polymer network based on an azo motif and a mechanically interlocked structure, as well as its preparation method and application (see patent specification with publication number CN119161553A). The photoresponsive polymer network is obtained by reacting raw materials including an azo motif, polytetrahydrofuran, hexamethylene diisocyanate, and a mechanically interlocked unit. This patented technology combines an azo motif with a slip ring system, which can be sterically altered by light. The cis-trans isomerization of the azo motif modulates the sliding ability of the macrocyclic ring in the mechanically interlocked unit. That is, the trans conformation slip ring is passable, while the cis conformation slip ring is not, thereby achieving the effect of using light stimulation to control the mechanical properties of the material (such as tensile properties, etc.). Summary of the Invention

[0006] The present invention provides a photoresponsive mechanically interlocked polymer network, its preparation method, and its application in photosensitive materials. This method introduces azo moieties that undergo cis-trans isomerization upon illumination into the mechanically interlocked polymer network to prepare a photoresponsive polymer network. The effects of illumination on the network's mechanical properties are studied. The network has potential applications in energy storage systems, switchable catalysis, controlled release and photopharmacology, and toughening agents.

[0007] [1] A photoresponsive mechanically interlocked polymer network obtained by reacting raw materials including an azo monomer, polytetrahydrofuran, isophorone diisocyanate, and a pseudorotaxane monomer;

[0008] The structure of the azo monomer is shown below:

[0009]

[0010] The pseudorotaxane monomer is formed by the host-guest interaction between benzo-21-crown-7 containing an olefin group at the end and a secondary ammonium salt with hydroxyl groups at both ends. The specific structure is shown below:

[0011]

[0012] The present invention provides a method for preparing the azo monomer, comprising the steps of:

[0013] (1) mixing 4,4'-dihydroxyazobenzene, monomer I, potassium carbonate and a first solvent for reaction, removing the first solvent after the reaction, extracting and purifying, and separating by column chromatography to obtain an azo monomer precursor;

[0014] The structure of the monomer I is shown below:

[0015]

[0016] (2) Under nitrogen protection, an azo monomer precursor, azobisisobutyronitrile, 1,3-propanedithiol and a second solvent are mixed for reaction. After the reaction is completed, the second solvent is removed, the mixture is extracted and purified, and the azo monomer is separated by column chromatography to obtain the azo monomer.

[0017] In step (1), optionally, the usage ratio of 4,4'-dihydroxyazobenzene, monomer I, potassium carbonate and the first solvent is 1 mmol:2.4-3.0 mmol:2-4 mmol:4-8 mL.

[0018] In step (1), optionally, the first solvent includes at least one of N,N-dimethylformamide and N,N-dimethylacetamide.

[0019] In step (1), optionally, the temperature of the mixing reaction is room temperature.

[0020] In step (1), optionally, the mixing reaction time is 12 to 24 hours.

[0021] In step (1), optionally, the extraction solvent used for the extraction purification includes dichloromethane.

[0022] In step (1), optionally, the eluent used in the column chromatography separation is dichloromethane and petroleum ether. Further optionally, in the eluent, the volume ratio of the dichloromethane to the petroleum ether is 3:1.

[0023] In step (2), optionally, the amount ratio of the azo monomer precursor, azobisisobutyronitrile, 1,3-propanedithiol and the second solvent is 1 mmol: 3-4 mmol: 15-20 mmol: 10-20 mL.

[0024] In step (2), optionally, the second solvent includes at least one of dichloromethane and N,N-dimethylacetamide.

[0025] In step (2), optionally, the temperature of the mixing reaction is 50 to 80°C.

[0026] In step (2), optionally, the mixing reaction time is 12 to 24 hours.

[0027] In step (2), optionally, the extraction solvent used for the extraction purification includes dichloromethane.

[0028] In step (2), optionally, the eluent used in the column chromatography separation is dichloromethane and petroleum ether. Further optionally, in the eluent, the volume ratio of the dichloromethane to the petroleum ether is 5:1.

[0029] Optionally, the number average molecular weight of the polytetrahydrofuran is 1000 to 2000 g / mol;

[0030] Optionally, in the raw materials, the total molar number of hydroxyl groups of polytetrahydrofuran and pseudorotaxane monomers is equal to the total molar number of NCO groups of isophorone diisocyanate.

[0031] Optionally, in the raw materials, the total molar number of thiol groups in the azo monomer is equal to the total molar number of olefin groups in the pseudorotaxane monomer.

[0032] The present invention provides a method for preparing the pseudorotaxane monomer, comprising:

[0033] At 40-50° C., reactant 3 and reactant 4 are mixed in dichloromethane for reaction, and the dichloromethane is removed after the reaction to obtain the pseudorotaxane monomer;

[0034] The reactant 3 has the following structure:

[0035]

[0036] The reactant 4 has the following structure:

[0037]

[0038] [2] The method for preparing a photoresponsive mechanically interlocked polymer network according to [1], comprising:

[0039] Under an inert atmosphere, polytetrahydrofuran, isophorone diisocyanate and pseudorotaxane monomers, a reaction solvent and an optional catalyst are mixed and reacted, and then an azo monomer is added. After it is completely dissolved, a photoinitiator is added and mixed evenly. The resulting mixed solution is irradiated with ultraviolet light to cause an olefin-thiol click reaction to obtain a molded sample; the molded sample is further cured and excess reaction solvent is removed to obtain the photoresponsive mechanical interlocking polymer network.

[0040] Optionally, the inert atmosphere is a nitrogen atmosphere.

[0041] Optionally, the reaction solvent is an organic solvent. Further optionally, the organic solvent includes at least one of dichloromethane, tetrahydrofuran, acetonitrile, and acetone.

[0042] Optionally, the catalyst comprises dibutyltin dilaurate.

[0043] Optionally, the photoinitiator includes benzoin dimethyl ether.

[0044] Optionally, the wavelength of the ultraviolet light is 360-370 nm, for example, 365 nm.

[0045] Optionally, the UV light intensity is 15 to 25 mW / cm 2 , for example 20mW / cm 2 wait.

[0046] Optionally, the temperature of the olefin-thiol click reaction is 30-50°C.

[0047] Optionally, the alkene-thiol click reaction takes 1 to 1.5 hours.

[0048] The method for preparing the photoresponsive mechanically interlocked polymer network can place the molded sample in a vacuum oven for further curing and removal of excess reaction solvent.

[0049] Optionally, the curing temperature is 55-65°C, such as 60°C.

[0050] Optionally, the curing time is 24 to 30 hours.

[0051] [3] Application of the photoresponsive mechanically interlocked polymer network according to [1] in photosensitive materials. The photoresponsive mechanically interlocked polymer network utilizes the cis-trans isomerization of azo to regulate the mechanical properties of the polymer, and is expected to be applied in the fields of toughening agents, energy storage systems, switchable catalysis, controlled release, and photopharmacology.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. The mechanically interlocked polymer network of the present invention has outstanding properties such as energy dissipation capacity and toughness. The azobenzene units are creatively added to the mechanically interlocked polymer network, making the network photoresponsive, and clarifying the changes in the mechanical properties of the network before and after illumination.

[0054] 2. The photoresponsive mechanically interlocked polymer network provided by the present invention has the potential to exert new functions and broaden application scenarios due to the addition of azo units, which changes its mechanical properties under light.

[0055] 3. The method for preparing the photoresponsive mechanical interlocking polymer network provided by the present invention is simple to operate, has a reliable route and is low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is the NMR comparison result of compound 3, compound 4 and pseudorotaxane monomer 2.

[0057] Figure 2 Schematic diagram of the synthesis of a photoresponsive mechanically interlocked polymer network of the present invention.

[0058] Figure 3 This is the infrared comparison result of azo monomer 1 (monomer 1), pseudorotaxane monomer 2 (monomer 2) and photoresponsive mechanically interlocked polymer network AC.

[0059] Figure 4 This is a diagram showing the swelling results of the polymer network AC of the present invention in Example 4.

[0060] Figure 5 Graph showing the thermogravimetric analysis results of the polymer networks AC of the present invention in Examples 1-3.

[0061] Figure 6 This is a diagram of the light response color change of the polymer network C of the present invention in Example 3, (A) left: polymer network C without illumination, (A) right: the color of the polymer network C after illumination for 1 hour, (B) left: polymer network C without illumination, (B) right: the color of the polymer network C after illumination for 1 hour and standing for 1 hour, (C) left: polymer network C without illumination, (C) right: the color of the polymer network C after illumination for 1 hour and standing for 3 hours.

[0062] Figure 7 Graph showing stress-strain test results of the polymer network AC (AC) of the present invention before and after irradiation at a stretching rate of 100 mm / min in Examples 1-3.

[0063] Figure 8 This is a graph showing the toughness results of the polymer network of Examples 1-3 before and after AC irradiation.

[0064] Figure 9 Graphs showing the cyclic stress-strain test results for the polymer network C of Example 3 before (A) and after (B) irradiation over a wide range of maximum applied strains from 100% to 500%.

[0065] Figure 10 Comparison of the energy dissipation value (A) and damping energy (B) of polymer network C in Example 3 before and after illumination. DETAILED DESCRIPTION

[0066] The present invention will be further described below with reference to the accompanying drawings and specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0067] In the present invention, the stress-strain curves are all measured at room temperature at a constant tensile rate of 100 mm / min. Young's modulus is determined by the initial slope of the stress-strain curve. Toughness is a parameter that characterizes the work required for fracture of each unit sample and is calculated based on the area below the stress-strain curve (until fracture). Energy dissipation is calculated by integrating the area contained in the cyclic tensile curve. Damping capacity is defined as the ratio of dissipated energy (the area enclosed by the loading and unloading curves) to the loaded energy (the area enclosed by the loading curve).

[0068] The number average molecular weight of the polytetrahydrofuran used in the following examples is 1000 g / mol.

[0069] Example 1:

[0070] Synthesis of azo monomer 1:

[0071]

[0072] (1) 4,4'-Dihydroxyazobenzene (23.4 mmol, 5 g) was added to a 500 mL round-bottom flask, and 100 mL of N,N-dimethylformamide (DMF) was added to dissolve the mixture. Then, an aqueous solution of potassium carbonate (72.3 mmol, 10.0 g) was added, and finally, 10-bromo-1-decene (56.8 mmol, 12.43 g) was added. The mixture was reacted at room temperature for 24 h. Thin layer chromatography (TLC) was performed. If the reaction was complete, the solvent was removed by distillation under reduced pressure, and dichloromethane (60 mL × 3) was added to the system for extraction. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure. The mixture was separated by column chromatography using dichloromethane / petroleum ether (volume ratio 3 / 1) as the eluent to obtain the azo unit precursor (4.92 g, 43%).

[0073] (2) Azo unit precursor

[0074]

[0075] Under nitrogen, the azo unit precursor (1.0 mmol, 492.0 mg) and azobisisobutyronitrile (AIBN) (3.0 mmol, 492.0 mg) were dissolved in 15 mL of dichloromethane. Subsequently, 1,3-propanedithiol (20 mmol, 2.160 g) was added to the reaction mixture via syringe and allowed to react at 80°C for 24 h. Thin-layer chromatography (TLC) was used to detect completion. If the reaction was complete, the solvent was removed by distillation under reduced pressure. Dichloromethane (60 mL x 3) was then added to the system for extraction. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and then distilled under reduced pressure. Separation by column chromatography using dichloromethane / petroleum ether (5 / 1 by volume) as the eluent yielded the azo unit 1 (4.24 g, 60%).

[0076] The H NMR results of the azo unit 1 of this example are as follows:

[0077] 1 H NMR (600MHz, CDCl3) δ (ppm): 7.86 (d, J = 8.7Hz, 4H), 6.98 (d, J = 8.7Hz, 4H), 4.03 (t, J = 6.5Hz, 4H), 2.70 -2.57(m,8H),2.50(t,J=7.4Hz,4H),1.93-1.84(m,4H),1.84-1.78(m,4H),1.60-1.54(m,8H),1.47(d,J=7.8Hz,4H),1.41-1.32(m,16H).

[0078] Synthesis of pseudorotaxane monomer 2:

[0079]

[0080] Reactant 3 (1.0 mmol, 455.0 mg) and reactant 4 (1.0 mmol, 582.0 mg) were added to a 25 mL round-bottom flask, dissolved in 10 mL of dichloromethane (DCM), and refluxed at 45°C for 6 h. The reaction was stopped and the solvent was dried to obtain pseudorotaxane monomer 2.

[0081] The NMR comparison results of pseudorotaxane monomer 2, reactants 3 and 4 are as follows: Figure 1 shown.

[0082] Synthesis of photoresponsive mechanically interlocked polymer network A (PPN-A):

[0083] Under nitrogen, polytetrahydrofuran (0.20 mmol), pseudorotaxane monomer 2 (0.20 mmol) of Example 1, isophorone diisocyanate (0.40 mmol) and reaction solvent DCM (2 mL) were added to the reaction bottle, and a drop of dibutyltin dilaurate was used as a catalyst. The system was stirred for 1 day. Then, azo monomer 1 (0.10 mmol) of Example 1 was added. After it was completely dissolved, photoinitiator benzoin dimethyl ether was added. The stirred mixed solution was poured into a mold and irradiated with an ultraviolet lamp (365 nm, 20 mW / cm 2 ) for one hour to initiate an olefin-thiol click reaction. The resulting sample was then placed in a 60°C vacuum oven for 24 hours to further cure the sample and remove excess solvent. The sample was then removed and cooled to room temperature to yield a photoresponsive mechanically interlocked polymer network A (PPN-A). The resulting mechanically interlocked polymer network A (PPN-A) was then tested for mechanical properties before and after irradiation with a 365nm light source for one hour.

[0084] Example 2

[0085] Synthesis of photoresponsive mechanically interlocked polymer network B (PPN-B):

[0086] Under nitrogen, polytetrahydrofuran (0.10 mmol), pseudorotaxane monomer 2 (0.20 mmol) of Example 1, isophorone diisocyanate (0.30 mmol) and reaction solvent DCM (2 mL) were added to the reaction bottle, and a drop of dibutyltin dilaurate was used as a catalyst. The system was stirred for 1 day. Then, azo monomer 1 (0.10 mmol) of Example 1 was added. After it was completely dissolved, photoinitiator benzoin dimethyl ether was added. The stirred mixed solution was poured into a mold and irradiated with an ultraviolet lamp (365 nm, 20 mW / cm 2 ) for one hour to initiate an olefin-thiol click reaction. The resulting sample was then placed in a 60°C vacuum oven for 24 hours to further cure the sample and remove excess solvent. The sample was then removed and cooled to room temperature to yield a photoresponsive mechanically interlocked polymer network B (PPN-B). The resulting mechanically interlocked polymer network B (PPN-B) was then tested for mechanical properties before and after 1 hour of 365nm irradiation.

[0087] Example 3

[0088] Synthesis of photoresponsive mechanically interlocked polymer networks C (PPN-C):

[0089] Under nitrogen, polytetrahydrofuran (0.10 mmol), pseudorotaxane monomer 2 (0.30 mmol) of Example 1, isophorone diisocyanate (0.40 mmol) and reaction solvent DCM (2 mL) were added to the reaction bottle, and a drop of dibutyltin dilaurate was used as a catalyst. The system was stirred for 1 day. Then, azo monomer 1 (0.15 mmol) of Example 1 was added. After complete dissolution, photoinitiator benzoin dimethyl ether was added. The stirred mixed solution was poured into a mold and irradiated with an ultraviolet lamp (365 nm, 20 mW / cm 2 ) for one hour to initiate an olefin-thiol click reaction. The resulting sample was then placed in a 60°C vacuum oven for 24 hours to further cure the sample and remove excess solvent. The sample was then removed and cooled to room temperature to yield a photoresponsive mechanically interlocked polymer network C (PPN-C). The resulting mechanically interlocked polymer network C (PPN-C) was then tested for mechanical properties before and after irradiation with a 365nm light source for one hour.

[0090] Figure 2This is a schematic diagram of the synthesis of a photoresponsive mechanically interlocked polymer network of the present invention. First, the hydroxyl groups in the pseudorotaxane monomer, the hydroxyl groups in polytetrahydrofuran, and isophorone diisocyanate are reacted to obtain a linear polymer. Then, the double bonds in the pseudorotaxane monomer and the thiol groups on the azo monomer react to generate a cross-linked photoresponsive mechanically interlocked polymer network.

[0091] Sample analysis:

[0092] The polymer networks prepared in Examples 1-3 were subjected to performance tests. Figure 3 The infrared spectra of the photoresponsive mechanical interlocked polymer network obtained in Examples 1-3, the azo monomer 1, and the pseudorotaxane monomer 2 show that the double bond in the pseudorotaxane monomer 2 is basically completely reacted. Figure 4 Swelling experiments showed that the polymer network only swelled but did not dissolve. These results further demonstrate that the double bond in pseudorotaxane monomer 2 and the thiol group in azo monomer 1 reacted completely, successfully preparing a photoresponsive mechanically interlocked polymer network. Figure 5 The thermogravimetric diagrams of the polymer networks prepared in Examples 1-3 show that the polymers have good thermal stability, with the temperatures at which 5% mass loss occurs being above 200°C. Figure 6 This is the photoresponsiveness diagram of the polymer network. It can be seen from the figure that the azo units in the polymer network can recover the trans conformation after being irradiated for 1 hour and then left to stand for 3 hours. Figure 7 The stress-strain curves of different polymer networks AC show that the maximum strain and maximum stress of the polymer network after illumination increase compared with those before illumination. Figure 8 The figure shows the toughness change of different polymer networks before and after illumination. It can be seen from the figure that the toughness of the polymer network increases after illumination; Figure 9 AB are the cyclic tensile curves of polymer network C before and after illumination, respectively, with increasing strain. It can be seen from the figure that the hysteresis loop of the polymer network increases with increasing strain, regardless of whether it is before or after illumination. This indicates that under high strain conditions, the sliding of the slip ring plays a dissipative role, thereby enhancing the toughness of the polymer network. Figure 10 AB are the energy dissipation value and damping energy of the polymer network C before and after illumination, respectively. It can be seen from the figure that the energy dissipation value and damping energy after illumination are greater than those before illumination.

[0093] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A mechanically interlocked polymer network with photoresponsiveness, characterized in that It is obtained by reacting raw materials including azo monomer, polytetrahydrofuran, isophorone diisocyanate and pseudorotaxane monomer; The structure of the azo monomer is shown below: The specific structure of the pseudorotaxane monomer is shown below:

2. The photoresponsive mechanically interlocked polymer network according to claim 1, wherein: The preparation method of the azo monomer comprises the steps of: (1) mixing 4,4'-dihydroxyazobenzene, monomer I, potassium carbonate and a first solvent for reaction, removing the first solvent after the reaction, extracting and purifying, and separating by column chromatography to obtain an azo monomer precursor; The structure of the monomer I is shown below: (2) Under nitrogen protection, an azo monomer precursor, azobisisobutyronitrile, 1,3-propanedithiol and a second solvent are mixed for reaction. After the reaction is completed, the second solvent is removed, the mixture is extracted and purified, and the azo monomer is separated by column chromatography to obtain the azo monomer.

3. The photoresponsive mechanically interlocked polymer network according to claim 2, wherein: In step (1): The ratio of 4,4'-dihydroxyazobenzene, monomer I, potassium carbonate and the first solvent is 1 mmol: 2.4-3.0 mmol: 2-4 mmol: 4-8 mL; The first solvent includes at least one of N,N-dimethylformamide and N,N-dimethylacetamide; The temperature of the mixed reaction is room temperature; The mixing reaction time is 12 to 24 hours; The extraction solvent used in the extraction purification includes dichloromethane; The eluents used in the column chromatography separation are dichloromethane and petroleum ether; in the eluent, the volume ratio of the dichloromethane to the petroleum ether is 3:

1.

4. The photoresponsive mechanically interlocked polymer network according to claim 2, wherein: In step (2): The ratio of the azo monomer precursor, azobisisobutyronitrile, 1,3-propanedithiol and the second solvent is 1 mmol: 3-4 mmol: 15-20 mmol: 10-20 mL; The second solvent includes at least one of dichloromethane and N,N-dimethylacetamide; The temperature of the mixed reaction is 50 to 80° C. The mixing reaction time is 12 to 24 hours; The extraction solvent used in the extraction purification includes dichloromethane; The eluents used in the column chromatography separation are dichloromethane and petroleum ether; in the eluent, the volume ratio of the dichloromethane to the petroleum ether is 5:

1.

5. The photoresponsive mechanically interlocked polymer network according to claim 1, wherein: The number average molecular weight of the polytetrahydrofuran is 1000 to 2000 g / mol; In the raw materials, the total molar number of hydroxyl groups of polytetrahydrofuran and pseudorotaxane monomers is equal to the total molar number of NCO groups of isophorone diisocyanate; In the raw materials, the total molar number of the mercapto groups in the azo monomer is equal to the total molar number of the olefin groups in the pseudorotaxane monomer.

6. The photoresponsive mechanically interlocked polymer network according to claim 1, wherein: The preparation method of the pseudorotaxane monomer comprises: At 40-50° C., reactant 3 and reactant 4 are mixed in dichloromethane for reaction, and the dichloromethane is removed after the reaction to obtain the pseudorotaxane monomer; The reactant 3 has the following structure: The reactant 4 has the following structure:

7. The method for preparing a photoresponsive mechanically interlocked polymer network according to any one of claims 1 to 6, wherein: include: Under an inert atmosphere, polytetrahydrofuran, isophorone diisocyanate and pseudorotaxane monomers, a reaction solvent and an optional catalyst are mixed and reacted, and then an azo monomer is added. After it is completely dissolved, a photoinitiator is added and mixed evenly. The resulting mixed solution is irradiated with ultraviolet light to cause an olefin-thiol click reaction to obtain a molded sample; the molded sample is further cured and excess reaction solvent is removed to obtain the photoresponsive mechanical interlocking polymer network.

8. The method for preparing a photoresponsive mechanically interlocked polymer network according to claim 7, wherein: The inert atmosphere is a nitrogen atmosphere; The reaction solvent is an organic solvent; the organic solvent includes at least one of dichloromethane, tetrahydrofuran, acetonitrile, and acetone; The catalyst includes dibutyltin dilaurate; The photoinitiator includes benzoin dimethyl ether; The wavelength of the ultraviolet light is 360-370 nm; The illumination intensity of the ultraviolet light is 15-25 mW / cm 2 ; The temperature of the olefin-thiol click reaction is 30 to 50° C.; The time of the alkene-thiol click reaction is 1 to 1.5 hours; The molded samples were placed in a vacuum oven for further curing and removal of excess reaction solvent; The curing temperature is 55-65°C; The curing time is 24 to 30 hours.

9. Use of the photoresponsive mechanically interlocked polymer network according to any one of claims 1 to 6 in photosensitive materials.

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