Functionalized pillar aromatic polyrotaxane and preparation method and application thereof

Abstract

The present invention discloses a functionalized pillar aromatic polyrotaxane and a preparation method and application thereof. The preparation method comprises the following steps: mixing polycaprolactone diol with modified ethoxy pillar [5] aromatic at low temperature, stirring for a period of time to form a pseudo-polyrotaxane, and then slowly adding a capping agent to react at low temperature to obtain a polyrotaxane. The polyrotaxane can be polymerized with butyl acrylate by free radicals to form a polyrotaxane-butyl acrylate covalent sliding ring polymer. Due to the sliding ring effect, the obtained sliding ring polymer has extremely strong ductility and resilience, laying a solid foundation for dynamic topological polymer materials.

Description

Technical Field

[0001] The invention relates to the field of polyrotaxane dynamic supramolecular materials, and in particular to a functionalized dynamic non-covalent bond pillar aromatic polyrotaxane and a preparation method and application thereof. Background Art

[0002] The mechanical motion of molecular machines is widely present in many life processes such as intracellular material transport and muscle contraction. Rotaxanes and pseudorotaxanes, one of the earliest models of molecular machines, have unique structures and fascinating stimulus-responsive properties. Since their discovery, they have been an important direction of supramolecular chemistry research. For polyrotaxanes, studies have found that there are mainly association and dissociation, as well as free shuttling motion of the cyclic part on the linear unit without blocking groups. The connection of mechanical bonds allows this type of molecule to maintain the overall structural stability while giving it dynamic properties, so it is often used to construct functional molecular materials. Moreover, rotaxanes are easier to functionalize and can be flexibly derived in the process of creating new materials. At the same time, the axial sliding range of rotaxanes is larger, and it is easier to regulate its motion behavior. Therefore, rotaxanes, polyrotaxanes and their derivatives with mechanical interlocking structures are important components for constructing new functional polymer material systems.

[0003] So far, rotaxane-type functional polymer material systems have attracted widespread attention. Professor Ito's research group at the University of Tokyo in Japan used water-soluble α-cyclodextrin and polyethylene glycol to form polyrotaxanes, and then connected two cyclodextrins through cyanuric chloride as sliding crosslinking points, and successfully prepared a low-viscosity, super-strong water-absorbing sliding ring hydrogel for the first time. Hydrogels have become the focus of attention for new polymer materials due to their unique advantages such as environmental protection, no pollution, no secondary pollution, easy recycling, and no need for complex equipment operation. Recently, Professor Ito's team used the rotaxane topological structure to propose a strain-induced crystallization hydrogel damage-free enhancement strategy. Compared with the covalently cross-linked polyethylene glycol hydrogel, the polyethylene glycol chains in the polymer network of the sliding ring material are exposed to each other and highly oriented under large stretching conditions. With stretching, crystals gradually form, and the crystals melt under contraction, thereby obtaining better toughness and recovery ability. However, the current construction of sliding ring polymers is based on the formation of interpenetrating structures based on hydrophilic and hydrophobic interactions. This core construction process must be carried out in the water phase, which greatly limits the use of traditional water-insoluble polymers to construct rotaxane materials. Therefore, the research in the field of sliding ring polymers is currently mainly focused on cyclodextrin and polyethylene glycol systems. Therefore, developing and introducing new forces to construct rotaxane interpenetrating structures, breaking through the limitation that the existing rotaxane system must be constructed in water phase, and enriching the polyrotaxane material system are the current problems to be solved in the field of rotaxane polymer research.

[0004] Pillarene is a classic structure of macrocyclic aromatic hydrocarbons. Since it was first reported by Professor Ogoshi of Kyoto University in Japan in 2008, it is not only simple to synthesize, but also has a unique cavity structure and easy functionalization, which gives it rich host-guest chemical properties, thus injecting new blood into supramolecular chemistry, especially the field of host-guest chemistry. The research group of Professor Huang Feihe of Zhejiang University first reported the host-guest interaction of pillar[5]arene / alkyl chain, and designed and constructed a series of new supramolecular polymers based on this. The research groups of Li Yongsheng and Lin Shaoliang of East China University of Science and Technology successfully prepared various new types of pseudo-polyrotaxanes with pillar[5]arene as the wheel in organic phase by using the host-guest interaction between pillar[5]arene and linear polymers containing alkyl chains (polyethylene, polycaprolactone, etc.). However, the simple pillararene polyrotaxane structure is difficult to modify in polymers because it has no active sites, so it cannot play the advantages of the rotaxane structure. Therefore, the preparation of polyrotaxane derivatives containing active sites is very important for the construction of functional polymers. After investigation, it was found that double-bond modified and monosubstituted pillar aromatic polyrotaxane derivatives have not been reported.

[0005] In summary, the present invention provides a method for preparing a functionalized pillar aromatic polyrotaxane, which provides ideas for obtaining new slide-ring materials with diverse structures and highly adjustable properties. Summary of the invention

[0006] In a first aspect, the present invention provides a method for preparing a functionalized pillar aromatic polyrotaxane, comprising the steps of:

[0007] (1) Add boron tribromide dropwise to a chloroform solution of ethoxylated column [5] aromatic hydrocarbon EtP5 under nitrogen protection at -6 to -15°C and allow the reaction to complete. After quenching the reaction, separate and extract the organic phase, dry it, separate and purify it to obtain the mono-eliminated ethoxylated column [5] aromatic hydrocarbon EtP5-OH. Low temperature reaction can effectively reduce the generation of by-products. If the temperature is too high, a large amount of column aromatic hydrocarbons with multiple alkyl chain elimination will be generated.

[0008] (2) preparing a dichloromethane or chloroform solution of mono-eliminated ethoxylated column [5] aromatic hydrocarbon EtP5-OH and triethylamine, adding a dichloromethane solution of methacryloyl chloride dropwise thereto in an ice bath, reacting at room temperature, and after the reaction, separating the solid and liquid to obtain the filtrate, washing with a saturated sodium bicarbonate solution, separating the layers, and drying and separating and purifying the organic phase to obtain the mono-olefin substituted ethoxylated column [5] aromatic hydrocarbon EtP5-MP; the mono-olefin substituted ethoxylated column [5] aromatic hydrocarbon EtP5-MP can be used for polymerization reaction, providing a perfect reaction site;

[0009] (3) preparing a chloroform solution of monoolefin-substituted ethoxylated pillar[5]arene EtP5-MP and polycaprolactone diol, stirring at room temperature for a period of time under nitrogen protection, and then continuing to stir at -30 to -40°C for a period of time to form a stable pseudo-polyrotaxane, then adding a chloroform solution of a capping agent 3,5-bis(trifluoromethyl)phenylisocyanate at -30 to -40°C and continuing the reaction at this temperature, and after the reaction is completed, dropping the mixture into ice methanol for precipitation and drying to obtain poly(modified ethoxylated pillar[5]arene-polycaprolactone)rotaxane PCL-MP, i.e., the functionalized pillar aromatic polyrotaxane.

[0010] In one embodiment, the preparation method of ethoxylated pillar[5]arene EtP5 comprises: adding paraformaldehyde and boron trifluoride etherate to a chloroform solution of p-diethoxybenzene, adding a saturated sodium bicarbonate solution to quench after complete reaction, separating the layers, washing the organic phase with a saturated sodium bicarbonate solution and purifying to obtain ethoxylated pillar[5]arene EtP5. In the preparation method of ethoxylated pillar[5]arene EtP5, boron trifluoride etherate provides an acidic environment, and chloroform has a template effect to help form the pillararene macrocycle.

[0011] In the preparation method of the ethoxylated column [5] aromatic hydrocarbon EtP5, the molar ratio of p-diethoxybenzene, paraformaldehyde and boron trifluoride etherate can be 1: (3.5-4.5): (0.8-1.2).

[0012] In one embodiment, in the method for preparing the ethoxylated column [5] aromatic hydrocarbon EtP5, the purification is performed by using silica gel column chromatography, and the eluent of the silica gel column chromatography is a mixture of petroleum ether and dichloromethane in a volume ratio of 1:1.

[0013] In a preferred embodiment, in step (1), the concentration of ethoxylated [5] aromatic hydrocarbon EtP5 in the chloroform solution of ethoxylated [5] aromatic hydrocarbon EtP5 is 0.1 g / mL. A high concentration of ethoxylated [5] aromatic hydrocarbon EtP5 can effectively increase the yield of single elimination of ethoxylated [5] aromatic hydrocarbon EtP5-OH.

[0014] In step (1), the molar ratio of ethoxylated column [5] aromatic hydrocarbon EtP5 to boron tribromide may be 1: (0.4-0.6).

[0015] In one embodiment, in step (1), the separation and purification is performed by using silica gel column chromatography, and the eluent of the silica gel column chromatography is a mixture of petroleum ether and ethyl acetate in a volume ratio of 20:1.

[0016] In step (2), the molar ratio of the single elimination ethoxylated column [5] aromatic hydrocarbon EtP5-OH, methacryloyl chloride and triethylamine can be 1: (1.0-1.4): (1.2-1.5).

[0017] In one embodiment, in step (2), the separation and purification is performed by using silica gel column chromatography, and the eluent of the silica gel column chromatography is a mixture of petroleum ether and ethyl acetate in a volume ratio of 45:1.

[0018] In step (3), the molar ratio of polycaprolactone diol to monoolefin-substituted ethoxylated column [5] aromatic hydrocarbon EtP5-MP can be 1: (20-24).

[0019] In step (3), the molar ratio of polycaprolactone diol to 3,5-bis(trifluoromethyl)phenyl isocyanate may be 1:(10-12).

[0020] In a second aspect, the present invention provides poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP prepared by the preparation method described in the first aspect.

[0021] In a third aspect, the present invention provides the use of the poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP described in the second aspect in the synthesis of functional polymer materials (such as elastomers, etc.).

[0022] In a fourth aspect, the present invention provides a method for preparing a polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR, comprising: preparing a tetrahydrofuran solution of the poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP described in the second aspect, azobisisobutyronitrile and butyl acrylate, and reacting the solution at 55 to 65° C. after deoxygenation to obtain the polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR.

[0023] The molar ratio of butyl acrylate to poly(modified ethoxylated pillar[5]arene-polycaprolactone) rotaxane PCL-MP can be 10000:(1-2) or 100:(5-10).

[0024] The molar ratio of butyl acrylate to azobisisobutyronitrile may be 100:(1-3).

[0025] In a fifth aspect, the present invention provides a polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR prepared by the preparation method described in the fourth aspect.

[0026] The polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR was prepared by free radical polymerization of poly(modified ethoxylated pillar[5]arene-polycaprolactone)rotaxane PCL-MP and butyl acrylate.

[0027] The polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR uses butyl acrylate as the polymer base and introduces poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP, so that the resulting polymer system has a sliding ring topology structure.

[0028] The invention utilizes the sliding ring characteristics of poly(modified ethoxy-column[5]arene-polycaprolactone) rotaxane PCL-MP to make the polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR have a complex topological structure.

[0029] Polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR has a complex sliding ring topological structure. It is a combination of supramolecules and polymers and is a very important type of elastomeric material.

[0030] Due to the sliding ring effect, the obtained sliding ring polymer has extremely strong ductility and resilience, laying a solid foundation for dynamic topological polymer materials.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1) The present invention provides a method for synthesizing poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP, wherein the synthesis method comprises mixing polycaprolactone diol with modified ethoxylated pillar [5] aromatic hydrocarbon at low temperature, stirring for a period of time to form a pseudo-polyrotaxane, and then slowly adding a capping agent and reacting at low temperature to obtain a polyrotaxane.

[0033] 2) The present invention provides an application of PCL-MP in the synthesis of a polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR. Butyl acrylate is used as a polymer substrate and polyrotaxane PCL-MP is introduced, so that the resulting polymer system has a sliding ring topological structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the synthesis route of polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR.

[0035] Figure 2 Chemical shift changes after modified ethoxylated [5]arene EtP5-MP (a) and polycaprolactone (c) formed poly(modified ethoxylated [5]arene-polycaprolactone) rotaxane PCL-MP (b).

[0036] Figure 3 This is the GPC result diagram of polycaprolactone before and after forming poly(modified ethoxy column [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP.

[0037] Figure 4 Schematic diagram of the crystal structure of PCL-MP forming an interpenetrating structure.

[0038] Figure 5 This is the infrared spectrum of the sliding ring polymer (MP-PR) formed by PCL-MP and butyl acrylate.

[0039] Figure 6This is a real stretching photograph of the sliding ring polymer MP-PR elastomer formed by PCL-MP and butyl acrylate (the molar content of PCL-MP is 0.2%, based on the molar amount of butyl acrylate is 100%). DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0041] Figure 1 The synthesis route of the polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR is presented, specifically:

[0042] 1. Synthesis of ethoxylated pillar[5]arene EtP5 having a structure as shown in Formula I below.

[0043]

[0044] p-Diethoxybenzene (6.00 g, 36 mmol) was added to 300 mL of chloroform, and paraformaldehyde (2.16 g, 144 mmol) and boron trifluoride ether (4.00 mL, 35 mmol) were added. The mixture was stirred at room temperature for 15 minutes. After the raw material completely disappeared, a saturated sodium bicarbonate solution was added to stop the reaction. The mixture was allowed to stand for separation to obtain an organic phase. The organic phase was washed twice with a saturated sodium bicarbonate solution and concentrated under reduced pressure to obtain a crude product. The crude product was purified by flash column chromatography (volume ratio of eluent petroleum ether / dichloromethane = 1:1) to obtain compound ethoxy [5] aromatics (3.28 g, yield 51.0%) as a white powder. The white powder was placed in a vacuum oven at 140°C and dried overnight, which was recorded as compound EtP5.

[0045] The structure of the synthesized ethoxylated column [5] aromatic hydrocarbon EtP5 was characterized. An appropriate amount of the final product was weighed into a nuclear magnetic resonance tube, dissolved in deuterated chloroform, and tested using a nuclear magnetic resonance spectrometer at 25°C. From the nuclear magnetic resonance spectrum of ethoxylated column [5] aromatic hydrocarbon EtP5, it can be seen that the chemical shift, integral and coupled splitting of each hydrogen are consistent with the target molecule, indicating that the target product was obtained, and the spectrum has no impurity peaks, proving that the product has reached a high purity.

[0046] EtP5 characterization data are as follows:

[0047] Compound EtP5. 1 H NMR (400MHz, CDCl3, 298K) δppm6.72 (s, 10H), 3.80-3,85 (q, J = 20.88Hz, 20H), 3.76 (s, 10H), 1.24-1.27 (t, J = 14.04Hz, 30H).

[0048] 2. Synthesis of the monoethoxylated column [5] aromatic hydrocarbon EtP5-OH having the structure shown in Formula II

[0049]

[0050] Ethoxy column [5] aromatic hydrocarbon EtP5 (3.00 g, 3.37 mmol) was added to 50 mL of chloroform, stirred at -6.9°C for 30 min, and slowly added with nitrogen protection and boron tribromide solution (0.78 g, 1.55 mmol), and continued to stir at -6 to -15°C for 10 min. After the raw material reaction was complete, 20 mL of ice water was slowly added to the reaction solution to quench the reaction. The layers were separated, and the organic phase was dried, filtered, and spin-dried to obtain a red crude product. The crude product was separated by column chromatography (eluent: petroleum ether / ethyl acetate = 20:1, v / v) to obtain 0.400 g of white solid powder EtP5-OH with a yield of 13.78%.

[0051] The structure of the synthesized single-eliminated ethoxyl column [5] aromatic hydrocarbon EtP5-OH was characterized. An appropriate amount of the final product was weighed into a nuclear magnetic resonance tube, dissolved in deuterated chloroform, and tested using a nuclear magnetic resonance instrument at 25°C. From the nuclear magnetic resonance spectrum of the single-eliminated ethoxyl column [5] aromatic hydrocarbon EtP5-OH, it can be seen that the chemical shift, integral and coupled splitting of each hydrogen are consistent with the target molecule, indicating that the target product has been obtained, and the spectrum has no impurity peaks, proving that the product has reached a high purity.

[0052] EtP5-OH characterization data are as follows:

[0053] Compound EtP5-OH. 1H NMR (600MHz, CDCl3, 298K) δppm 6.90(s,1H),6.76(s,1H),6.68-6.70(d,J=10.62Hz,2H),6.63-6.65(d,J=9.06Hz,3H),6.54-6.55(d,J=5.64Hz,3H), 6.49(s,1H),4.01-4.04(q,J=20.82Hz,2H),3.89-3.92(q,J=21.00Hz,2H),3.83-3.87(q,J=20.7Hz,2H),3.71-3.80(m ,J=56.22Hz,20H),3.62-3.66(q,J=20.82Hz,2H),1.35-1.41(m,J=38.88Hz,9H),1.21-1.23(t,J=13.92Hz,3H),1.16- 1.19(q,J=19.20Hz,6H), 1.12-1.14(t,J=13.92Hz,3H), 1.07-1.10(t,J=13.92Hz,3H), 1.02-1.05(t,J=13.98Hz,3H).

[0054] 3. Synthesis of ethoxylated pillar [5] aromatic hydrocarbon-monosubstituted olefin EtP5-MP having the structure shown in Formula III

[0055]

[0056] The mono-ethoxylated column [5] aromatic hydrocarbon EtP5-OH (1.20 g, 1.39 mmol) and triethylamine (196 mg, 1.94 mmol) were added to 20 mL of anhydrous dichloromethane, and the anhydrous dichloromethane dilution of methacryloyl chloride (188 μL, 1.94 mmol) was slowly added dropwise under an ice bath. After the temperature rose to room temperature, the reaction was continued for 12 h. Stirring was stopped, the insoluble matter in the reaction solution was filtered off, the filtrate was washed with a saturated sodium bicarbonate solution, the layers were separated, the organic phase was dried, filtered, and the white solid was obtained by spin drying. The crude product was separated by column chromatography (eluent: petroleum ether / ethyl acetate = 45:1, v / v) to obtain 1.05 g of white solid EtP5-MP, with a yield of 81.0%.

[0057] The structure of the synthesized ethoxylated column [5] aromatic hydrocarbon-monosubstituted olefin EtP5-MP was characterized. An appropriate amount of the final product was weighed into a nuclear magnetic resonance tube, dissolved in deuterated chloroform, and tested using a nuclear magnetic resonance spectrometer at 25°C. From the nuclear magnetic resonance spectrum of the ethoxylated column [5] aromatic hydrocarbon-monosubstituted olefin EtP5-MP, it can be seen that the chemical shift, integral and coupled splitting of each hydrogen are consistent with the target molecule, indicating that the target product was obtained, and the spectrum has no impurity peaks, proving that the product has reached a high purity.

[0058] EtP5-MP characterization data are as follows:

[0059] Compound EtP5-MP. 1 H NMR (600MHz, CDCl3, 298K) δppm 6.92(s,1H),6.71-6.73(M,J=13.92Hz,5H),6.69(s,1H),6.66-6.67(d,J= 4.92Hz,2H),6.52(s,1H),6.31(s,1H),5.72(s,1H),3.82-3,85(q,J=20.8 2Hz,8H),3.75-3.80(m,J=33.60Hz,18H),3.64(s,2H),1.23-1.28(m,J=29 .04Hz, 18H), 1.19-1.22 (m, J = 17.58Hz, 8H), 1.16-1.18 (t, J = 14.10Hz, 4H).

[0060] 4. Synthesis of poly(modified ethoxylated pillar[5]arene-polycaprolactone) rotaxane PCL-MP having the structure shown in Formula IV

[0061]

[0062] Ethoxy [5] aromatic hydrocarbon-monosubstituted olefin EtP5-MP (0.91 g, 0.98 mmol) and polycaprolactone diol PCL-OH (0.2 g, Mn: 4000, 0.05 mmol) were added to 10 mL of anhydrous chloroform, and stirred at room temperature for 6 h under nitrogen protection, then stirred at -35 ° C for 6 h, and then slowly added 3,5-bis (trifluoromethyl) phenyl isocyanate (0.10 mL, 0.58 mmol) in anhydrous chloroform dilution under low temperature environment, and continued to react at -35 ° C for 72 h. Stop stirring, slowly drop the reaction solution into ice methanol, let it stand for half an hour, and then filter it. The filter residue was washed with ice methanol, and the filter residue was dissolved with chloroform again. The resulting liquid was dropped into ice methanol, filtered, and dried to obtain 0.30 g of white powder solid PCL-MP, with a yield of 68.2%.

[0063] The structure of the synthesized poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP was characterized. An appropriate amount of the final product was weighed into a nuclear magnetic resonance tube, dissolved in deuterated chloroform, and tested using a nuclear magnetic resonance spectrometer at 25°C. From the nuclear magnetic resonance spectrum of poly(modified ethoxylated pillar [5] aromatic hydrocarbon-polycaprolactone) rotaxane PCL-MP, it can be seen that the chemical shift, integral and coupling splitting of each hydrogen are consistent with the target molecule, indicating that the target product was obtained, and the spectrum has no impurity peaks, proving that the product has reached a high purity.

[0064] The PCL-MP characterization data are as follows:

[0065] Compound PCL-MP. 1 H NMR (600MHz, CDCl3, 298K) δppm 8.01-8.07(t,3H),7.51-7.57(t,3H),7.05(m,17H),6.93(m,60H),6.50-6.56(t,8H),6.69(m,8 H),5.80(s,7H),3.78-4.06(m,252H),2.17(s,32H),1.50(s,190H),1.42(m,28H),1.26(s,9H).

[0066] From the NMR, each pair of end groups (7.51-7.57) corresponds to 7-8 aromatic hydrogens (6.50-6.56) of ethoxylated [5] aromatic hydrocarbons-monosubstituted olefins EtP5-MP. This indicates that each chain of poly (modified ethoxylated [5] aromatic hydrocarbons-polycaprolactone) rotaxane PCL-MP has 7-8 ethoxylated [5] aromatic hydrocarbons-monosubstituted olefins EtP5-MP.

[0067] like Figure 2 As shown, when ethoxylated [5] aromatic hydrocarbon-monosubstituted olefin EtP5-MP and polycaprolactone diol PCL form a host-guest complex, the hydrogen atoms of ethoxylated [5] aromatic hydrocarbon-monosubstituted olefin EtP5-MP move to the low field, while the hydrogen atoms of polycaprolactone diol PCL move to the high field, which also proves the formation of polyrotaxane.

[0068] Polycaprolactone PCL and PCL-MP were dissolved in tetrahydrofuran, filtered, and then the molecular weight was tested by gel exclusion chromatography. The results were as follows: Figure 3 As shown in the figure, the median molecular weight of PCL-MP is 4565 more than that of PCL, and the difference between the two corresponds to the molecular weight of 5 EtP5-MPs. This indicates that each chain of poly(modified ethoxylated pillar[5]arene-polycaprolactone) rotaxane PCL-MP is covered with 5 ethoxylated pillar[5]arene-monosubstituted olefin EtP5-MPs.

[0069] Figure 4 Schematic diagram of the crystal structure of PCL-MP forming an interpenetrating structure, indicating that the PCL chain can penetrate into the cavity of ethoxylated pillar[5]arene.

[0070] 5. Synthesis of polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR

[0071] Dissolve polyrotaxane PCL-MP (200 mg, 0.02 mmol), azobisisobutyronitrile (0.0027 g, 0.001 mmol) and butyl acrylate (2.56 g, 10.0 mmol) in 5 mL of anhydrous tetrahydrofuran to obtain a precursor solution, then place the precursor solution in liquid nitrogen, ventilate for 30 minutes to remove the air in the solution, and then react the treated solution at 60°C for 6 hours. Stop heating, carefully pour the obtained organogel into the mold, evaporate at room temperature for a period of time, place it in a vacuum drying oven and heat it at 80°C overnight, and dry the obtained gel sheet and press it into a polymer film using a hot press. Infrared spectroscopy characterization of polyrotaxane-butyl acrylate covalent polymer MP-PR is shown in Figure 5 , illustrating the formation of the sliding ring polymer. Figure 6 The actual tensile and rebound properties of polyrotaxane-butyl acrylate covalent polymer MP-PR are demonstrated, indicating that it is an elastomer with excellent performance.

[0072] In summary, the present invention can prepare polyrotaxane-butyl acrylate covalent sliding ring polymer MP-PR, and the obtained sliding ring polymer has extremely strong ductility and resilience ( Figure 6 ), laying a solid foundation for dynamic topological polymer materials.

[0073] 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 method for preparing a functionalized pillar aromatic polyrotaxane, characterized in that: Includes steps: (1) Add boron tribromide dropwise to a chloroform solution of ethoxylated column [5] aromatic hydrocarbon EtP5 under nitrogen protection at -6 to -15°C and allow the reaction to complete. After quenching the reaction, separate and extract the organic phase, dry it, separate and purify it to obtain the mono-eliminated ethoxylated column [5] aromatic hydrocarbon EtP5-OH; (2) preparing a dichloromethane or chloroform solution of mono-eliminated ethoxylated column [5] aromatic hydrocarbon EtP5-OH and triethylamine, adding a dichloromethane solution of methacryloyl chloride dropwise thereto in an ice bath, reacting at room temperature, and after the reaction, separating the solid and liquid to obtain the filtrate, washing with a saturated sodium bicarbonate solution, separating the layers, and drying the organic phase, separating and purifying to obtain the mono-olefin substituted ethoxylated column [5] aromatic hydrocarbon EtP5-MP; (3) preparing a chloroform solution of monoolefin-substituted ethoxylated pillar[5]arene EtP5-MP and polycaprolactone diol, stirring at room temperature for a period of time under nitrogen protection, and then continuing to stir at -30 to -40°C for a period of time to form a stable pseudo-polyrotaxane, then adding a chloroform solution of a capping agent 3,5-bis(trifluoromethyl)phenylisocyanate at -30 to -40°C and continuing the reaction at this temperature, and after the reaction is completed, dropping the mixture into ice methanol for precipitation and drying to obtain poly(modified ethoxylated pillar[5]arene-polycaprolactone)rotaxane PCL-MP, i.e., the functionalized pillar aromatic polyrotaxane.

2. The preparation method according to claim 1, characterized in that: The preparation method of ethoxylated column [5] aromatic hydrocarbon EtP5 comprises: adding paraformaldehyde and boron trifluoride etherate to a chloroform solution of p-diethoxybenzene, adding a saturated sodium bicarbonate solution to quench after complete reaction, separating the layers, washing the organic phase with a saturated sodium bicarbonate solution and purifying to obtain ethoxylated column [5] aromatic hydrocarbon EtP5; In the preparation method of the ethoxylated column [5] aromatic hydrocarbon EtP5: The molar ratio of p-diethoxybenzene, paraformaldehyde and boron trifluoride etherate is 1:(3.5-4.5):(0.8-1.2); The purification is performed by using silica gel column chromatography, and the eluent of the silica gel column chromatography is a mixture of petroleum ether and dichloromethane in a volume ratio of 1:

1.

3. The preparation method according to claim 1, characterized in that: In step (1): The molar ratio of ethoxylated column [5] aromatic hydrocarbon EtP5 to boron tribromide is 1:(0.4-0.6); The separation and purification is carried out by using silica gel column chromatography, and the eluent of the silica gel column chromatography is a mixture of petroleum ether and ethyl acetate in a volume ratio of 20:

1.

4. The preparation method according to claim 1, characterized in that: In step (2): Single elimination of ethoxyl column [5] The molar ratio of aromatic hydrocarbon EtP5-OH, methacryloyl chloride and triethylamine is 1:(1.0-1.4):(1.2-1.5); The separation and purification is carried out by using silica gel column chromatography, and the eluent of the silica gel column chromatography is a mixture of petroleum ether and ethyl acetate in a volume ratio of 45:

1.

5. The preparation method according to claim 1, characterized in that: In step (3): The molar ratio of polycaprolactone diol to monoolefin-substituted ethoxylated pillar[5]arene EtP5-MP is 1:(20-24); The molar ratio of polycaprolactone diol to 3,5-bis(trifluoromethyl)phenyl isocyanate is 1:(10-12). 6 . The poly(modified ethoxy pillar[5]arene-polycaprolactone) rotaxane PCL-MP prepared by the preparation method according to claim 1 .

7. Use of the poly(modified ethoxylated pillar[5]arene-polycaprolactone)rotaxane PCL-MP according to claim 6 in the synthesis of functional polymer materials.

8. The use according to claim 7, characterized in that: The functional polymer material is an elastomer.

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