Vinyl group-introduced GHG-type insertion-type rotaxane and polymer containing vinyl group-introduced GHG-type insertion-type rotaxane in side chain or main chain

Abstract

To provide a polymer containing an insertion-type rotaxane having more excellent compression resistance and a self-repairing property.SOLUTION: A polymer containing a GHG-type insertion type rotaxane obtained by introducing a vinyl group into a secondary ammonium salt in a side chain, and a polymer containing a GHG-type insertion type rotaxane obtained by introducing a vinyl group into a secondary ammonium salt in a main chain.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a GHG-type interdigitating rotaxane having a vinyl group introduced therein, and a polymer containing a GHG-type interdigitating rotaxane having a vinyl group introduced therein in a side chain or main chain. [Background technology]

[0002] A rotaxane is a molecular complex (supramolecular compound) in which an axial molecule (axial molecule) penetrates the interior of a cyclic molecule (ring molecule), with both ends of the axial molecule further attached with compounds (stoppers) larger than the inner diameter of the cyclic molecule. In this state, the cyclic molecule is confined on the axial molecule by the two stoppers, allowing the axial molecule and cyclic molecule to exist in a stable state in which they cannot dissociate. When a large number of cyclic molecules are incorporated, they are called polyrotaxanes. These cyclic molecules are bonded to each other by intermolecular bonding, resulting in a flexible and tough network polymer material in which the cyclic molecules move along the axial molecule. Such materials can distribute external stress uniformly throughout the material, resulting in higher deformation strength and durability compared to conventional chemically crosslinked network polymers, and some have already been commercialized.

[0003] Furthermore, one unique type of rotaxane is the intercalated rotaxane ([c2]daisy-chain rotaxane). Intercalated rotaxanes are host-guest integrated compounds (HG compounds) in which a cyclic molecule (hereinafter also referred to as the "host") and an axial molecule (hereinafter also referred to as the "guest") are fused into a single molecule. The two molecules intercalate by intermolecular interactions, resulting in the guest moiety being inserted into the host moiety of the other molecule. By introducing stoppers to the ends of each axial end, intercalated rotaxanes form stable inclusion structures, becoming topological molecules in which the distance between the two cyclic molecules is continuously variable. Because intercalated rotaxanes reversibly dissociate upon application of external stimuli such as heat or light, research is currently underway aimed at their application to new materials. Patent Document 1 discloses the polymerization (Huisgen cycloaddition) of intercalated rotaxane monomers using a copper catalyst as a metal catalyst.

[0004] Rotaxane polymers obtained by sequentially linking rotaxanes are classified into interlocked types (interlock compounds) and interdigitated types. Polymeric materials that enable contractile movement are being developed using interdigitated rotaxane polymers. By applying a stimulus to the polymerized interdigitated rotaxane, it is possible to cause the entire molecule to contract like muscle fibers, and applications such as artificial muscles are expected. Patent Document 2 discloses a crosslinked polymer composition obtained by crosslinking a polyrotaxane in which cyclic molecules have hydrosilyl groups with a polymer having double bonds using a platinum catalyst.

[0005] Non-Patent Documents 1 and 2 disclose the synthesis of an interdigitating rotaxane polymer using a 24-membered crown ether as a cyclic molecule and a copper catalyst, but do not describe properties such as compression resistance of the resulting rotaxane polymer. Non-Patent Document 3 discloses the synthesis of an interdigitating rotaxane monomer using a 24-membered crown ether as a cyclic molecule and a copper catalyst, which is synthesized using a ruthenium catalyst, but the resulting rotaxane polymer is not a film, and there is no description of properties such as compression resistance.

[0006] The present inventors synthesized linear or network polymers by reacting a stopper-free intercalating rotaxane ([c2]daisy-chain rotaxane) with a crosslinker having a terminal thiol group. The resulting polymers were able to form stable inclusion structures in which the inclusion units did not collapse without the need for the introduction of bulky stoppers, enabling the one-step synthesis of functional polymers using HG compounds. Additionally, the inventors discovered that introducing a rotaxane structure into a polymer material can impart excellent compression resistance with stress relaxation, and filed a patent application (Japanese Patent Application No. 2022-188248). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-121933 [Patent Document 2] Patent Publication No. 2021-127362 [Non-patent literature]

[0008] [Non-Patent Document 1] Bistable [c2]Daisy Chain Rotaxanes as Reversible Muscle-like Actuators in Mechanically Active Gels, J. AM. Chem. Soc., 139, 14825-14828 (2017) [Non-patent document 2] Muscle-like Supramolecular Polymer: Integrated motion from Thousands of Molecular Machines, Angew. Chem. Int. Ed., 51, 12504-12508 (2012) [Non-patent document 3] Switching and Extension of a [c2]daisy-chain Dimer Polymer, J. AM. Chem. Soc., 131, 13631-13633 (2009) Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, linear and network polymers have been synthesized as interdigitated rotaxane ([c2]daisy-chain rotaxane) polymers, making it possible to impart excellent compression resistance to stress relaxation. However, when a strong force exceeding the stress relaxation capacity of the rotaxane units is applied to these network polymer materials containing interdigitated rotaxane ([c2]daisy-chain rotaxane), the network structure itself is destroyed and cannot be restored to its original state. Therefore, it has been a challenge to provide polymers containing interdigitated rotaxanes that have better compression resistance and self-healing properties.

[0010] The present inventors discovered that GHG compounds in which axial molecules (guests) are introduced on both sides of a cyclic molecule (host) form GHG-type interdigitating rotaxanes. Based on this discovery, the inventors also discovered that a GHG-type interdigitating rotaxane in which a vinyl group is introduced into a secondary ammonium salt not involved in the inclusion complex functions as both a cross-linking agent and an electrophile, leading to the present invention.

[0011] Specifically, the present invention relates to a GHG-type interdigitating rotaxane in which a vinyl group has been introduced into a secondary ammonium salt, which is specified by the following items; a polymer containing a GHG-type interdigitating rotaxane in which a vinyl group has been introduced into a secondary ammonium salt in its side chain and a method for producing the same; and a polymer containing a GHG-type interdigitating rotaxane in which a vinyl group has been introduced into a secondary ammonium salt in its main chain and a method for producing the same. [1] In the GHG-type intercalating rotaxane represented by chemical formula (1), a vinyl group is introduced into the secondary ammonium salt that is not involved in the inclusion. [ka] [2] A polymer containing a GHG-type intercalating rotaxane in the side chain, in which a vinyl group has been introduced into the secondary ammonium salt described in [1]. [3] A method for producing the polymer described in [2] by using a GHG-type intercalating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt described in [1] as a crosslinking agent and carrying out a radical polymerization reaction with a vinyl group-containing monomer. [4] A polymer containing a GHG-type intercalating rotaxane in the main chain, in which a vinyl group has been introduced into the secondary ammonium salt described in [1]. [5] The polymer according to [4], wherein the polymer is self-healing. [6] The polymer according to [4], wherein the polymer is a linear polymer. [7] The polymer according to [4], wherein the polymer is a network polymer. [8] A method for producing the polymer described in [4] by using a GHG-type intercalating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt described in [1] as an electrophile and subjecting it to a Michael addition reaction with a thiol compound. [Effects of the Invention]

[0012] According to the present invention, a GHG-type interdigitating rotaxane in which a vinyl group has been introduced into a secondary ammonium salt that is not involved in inclusion is used as a crosslinking agent to provide a polymer containing a GHG-type interdigitating rotaxane in its side chain with improved compression resistance, and further, when used as an electrophile, a polymer containing a GHG-type interdigitating rotaxane in its main chain with linear or mesh-like self-repairing properties is provided. [Brief explanation of the drawings]

[0013] [Figure 1] shows the chemical structure of the compound DFB24C8 and its 1H NMR spectrum. [Figure 2] shows the chemical structure of compound BIB24C8 and its 1H NMR spectrum. [Figure 3] shows the chemical structure of compound BAB24C8 and its 1H NMR spectrum. [Figure 4] shows the chemical structure of the compound GHG_2PF6 and its 1H NMR spectrum. [Figure 5] Figure 1 shows the chemical structure of a GHG compound in which a vinyl group has been introduced into a secondary ammonium salt not involved in the inclusion complex, obtained by reacting a GHG-type intercalated rotaxane with MOI-EG, and the chemical structure of the GHG-type intercalated rotaxane, as well as the 1H NMR spectra in CD3CN and DMSO-d6. [Figure 6] Figure 1 shows the chemical structure of a GHG compound in which a vinyl group has been introduced into a secondary ammonium salt that is not involved in the inclusion complex, obtained by reacting a GHG-type intercalated rotaxane with AOI, and the chemical structure of the GHG-type intercalated rotaxane, as well as the 1H NMR spectra in CD3CN and DMSO-d6. [Figure 7] The figure shows a comparison of the compression resistance test results between a polymer containing a GHG-type intercalated rotaxane in the side chain, in which a vinyl group has been introduced into a secondary ammonium salt, and a DGMEM homopolymer. [Figure 8] This paper shows the change in the inclusion structure due to the swelling behavior of a polymer containing a GHG-type intercalated rotaxane in the side chain, in which a vinyl group has been introduced into a secondary ammonium salt, in acetonitrile and dimethylformamide (DMF). [Figure 9] shows the 1H NMR spectrum of (i) a GHG-type intercalated rotaxane in which a vinyl group was introduced into a secondary ammonium salt not involved in the inclusion complex, (ii) the 1H NMR spectrum of DODT, and (iii) the 1H NMR spectrum of the resulting DODT polymer in CD3CN. [Figure 10]shows the glass transition temperatures of linear polymers ([c2]daisy-chain rotaxane-co-DODT polymers) and network polymers ([c2]daisy-chain rotaxane-co-PTMA polymers) containing GHG-type intercalated rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts. [Figure 11] The figure shows the dissolution state of polymers containing GHG-type intercalated rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts ([c2]daisy-chain rotaxane-co-DODT polymer and [c2]daisy-chain rotaxane-co-PTMA polymer) in acetonitrile (CH3CN) and dimethylformamide (DMF). [Figure 12] The figure shows the 1H NMR spectra of a (network) polymer of PTMA and a GHG-type intercalated rotaxane ([c2]daisy-chain rotaxane-co-PTMA polymer) in CD3CN and DMSO-d6. [Figure 13] shows the inclusion and dissociation states of a linear polymer containing a GHG-type intercalated rotaxane in the main chain, in which a vinyl group has been introduced into a secondary ammonium salt. [Figure 14] The figure shows the maintenance and collapse of the inclusion structure of [c2]daisy-chain rotaxane-co-PTMA polymer in CD3CN and DMSO-d6, as well as the 1H NMR spectrum. [Figure 15] This shows the results of a test of the self-healing ability based on the appearance of a polymer of PTMA and a GHG-type intercalated rotaxane in which a vinyl group has been introduced into a secondary ammonium salt ([c2]daisy-chain rotaxane-co-PTMA polymer). [Figure 16] The figure shows the results of compression tests (1st to 3rd measurements) on a network polymer ([c2]daisy-chain rotaxane-co-PTMA polymer) containing a GHG-type intercalated rotaxane in the main chain, in which a vinyl group has been introduced into a secondary ammonium salt. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention relates to the production of polymers with useful properties by using a GHG-type intercalating rotaxane ([c2]daisy-chain rotaxane) in which a vinyl group has been introduced into a secondary ammonium salt that is not involved in the inclusion reaction as a crosslinking agent or electrophile.

[0015] [GHG-type intercalated rotaxanes with vinyl groups attached to secondary ammonium salts not involved in the inclusion complex] The design outlines of the GHG compound (compound (1)), which is a crown ether derivative having two ammonium salts, the GHG-type interdigitated rotaxane containing a crown ether derivative having two ammonium salts ([c2]daisy-chain rotaxane, compound (2)), and the GHG-type interdigitated rotaxane compound 3, in which a vinyl group has been introduced into a secondary ammonium salt not involved in the inclusion complex, which are the basic frameworks of the present invention, are shown below. [ka] According to the design outline, a host-guest integrated compound (GHG compound) incorporating a cyclic molecule and an axial molecule capable of forming a complementary inclusion complex in a molar ratio of 1:2 was synthesized using (dibenzo)crown ether and a secondary ammonium salt. The resulting GHG compound was then dissolved in an organic solvent, where it spontaneously formed an inclusion compound (intercalated rotaxane; [c2]daisy-chain rotaxane) between the two molecules. Two free secondary ammonium salts, not involved in the inclusion complex, exist per intercalated rotaxane, and the guest unit, the secondary ammonium salt, was used as a reaction origin to synthesize a GHG-type intercalated rotaxane with a vinyl group introduced.

[0016] The crown ether used as the cyclic molecule (host) in the present invention is a crown ether with 24 ring members, but the number of ring members of the crown ether is not limited to 24; crown ethers with 21 to 31 ring members can be used. Crown ethers with 21, 24, or 30 ring members are preferred, and crown ethers with 24 ring members are more preferred. Furthermore, hexylamine is used as the alkylamine, which is the axial molecule (guest), but is not limited to hexylamine. The length of the carbon chain of the alkylamine is not limited; it can be a carbon chain with 5 to 30 carbon atoms. The carbon chain may also contain a group containing atoms other than carbon atoms, such as ether, ester, amide, or thioether. Examples of organic solvents that dissolve GHG compounds include acetonitrile, dioxane, benzene, toluene, chloroform, chlorobenzene, dichloromethane, 1,2-dichloroethane, acetone, nitromethane, sulfolane, and 3-methylsulfolane. The compound having a vinyl group used for introducing the vinyl group is not particularly limited, and compounds that are commonly used for introducing a vinyl group, such as acrylates and methacrylates, can be used.

[0017] [Polymers containing GHG-type intercalated rotaxanes in the side chains, in which vinyl groups have been introduced into secondary ammonium salts] and [A method for producing polymers by radical polymerization of vinyl-containing monomers using GHG-type intercalating rotaxanes, in which vinyl groups have been introduced into secondary ammonium salts, as crosslinkers] The polymer of the present invention, which contains a GHG-type interdigitating rotaxane in the side chain, in which a vinyl group has been introduced into a secondary ammonium salt, can be produced by radical polymerization of a vinyl-containing monomer using the GHG-type interdigitating rotaxane in which a vinyl group has been introduced into a secondary ammonium salt as a crosslinker. Examples of the vinyl-containing monomer that can be used include, but are not limited to, methyl methacrylate (MMA), 2-methoxyethyl methacrylate (MEM), and diethylene glycol monomethyl ether methacrylate (DGMEM). The polymerization conditions for the radical polymerization reaction are also not particularly limited, and the polymerization conditions used for typical radical polymerization reactions, including the polymerization initiator and UV irradiation, can be used. The schematic diagram of the synthesis of a polymer containing a GHG-type intercalated rotaxane in the side chain, in which a vinyl group has been introduced into a secondary ammonium salt, and the dissociation and inclusion of the produced polymer, are shown below. [ka]

[0018] As shown in the conceptual diagram above, the polymer of the present invention, which contains a GHG-type intercalating rotaxane in its side chain, in which a vinyl group has been introduced into a secondary ammonium salt, contains a GHG-type intercalating rotaxane in its side chain as a crosslinker. This allows for repeated dissociation and inclusion in response to changes in the external environment (external stimuli), resulting in a material with excellent compression resistance. Furthermore, the polymer of the present invention exhibits unique swelling behavior based on dissociation and inclusion in specific organic solvents, allowing for reversible and wide-ranging control of the crosslink density in the gel state. Furthermore, the polymer of the present invention allows for arbitrary control of the monomer composition ratio in the radical copolymerization with a general-purpose vinyl monomer, allowing for a wider range of control of the crosslink density and resulting in high swelling properties.

[0019] Examples of solvents used for dissociation or inclusion due to a change in the external environment (external stimulus) include N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and dimethylacetamide (DMAC) for dissociation, and acetonitrile, dioxane, benzene, toluene, chloroform, chlorobenzene, dichloromethane, 1,2-dichloroethane, acetone, nitromethane, sulfolane, and 3-methylsulfolane for inclusion.

[0020] [Polymers containing GHG-type intercalated rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts] and [A method for producing polymers by Michael addition reaction of a GHG-type intercalated rotaxane, in which a vinyl group is introduced into a secondary ammonium salt, with a thiol compound as an electrophile] Polymers containing GHG-type interdigitating rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts, can be produced as self-healing polymers by Michael addition reaction of the GHG-type interdigitating rotaxanes in which vinyl groups have been introduced into secondary ammonium salts with a multi-branched thiol compound (nucleophile) using the GHG-type interdigitating rotaxanes in which vinyl groups have been introduced into secondary ammonium salts as electrophiles. Linear polymers can be produced by using dithiol compounds with bibranched structures as the multi-branched thiol compound, while network polymers can be produced by using trithiol compounds with tri-branched structures, tetrathiol compounds with tetra-branched structures, hexathiol compounds with hexa-branched structures, or octathiol compounds with octa-branched structures as the multi-branched thiol compound. In the Michael addition reaction, a base is used as a deprotonation reagent, but the base is not particularly limited, and amine compounds such as triethylamine can be used. Schematic diagrams of the production of linear polymers using dithiol compounds and the production of network polymers using tetrathiol compounds are shown in [Chemical Formula 4] and [Chemical Formula 5], respectively. [ka] [ka]

[0021] Polymers containing GHG-type interdigitating rotaxanes in their main chains, in which vinyl groups have been introduced into secondary ammonium salts, are constructed by numerous pseudo-bonds formed by the GHG-type interdigitating rotaxanes. However, because this structure utilizes unstable physical bonds, changes in the external environment (external stimuli) such as pH, temperature, solvent, and stress can cause the GHG-type interdigitating rotaxanes to dissociate and destroy the polymer structure. However, by normalizing the external environment, inclusion occurs again, and the polymer self-repairs and recovers as a polymer containing GHG-type interdigitating rotaxanes in its main chain. In other words, the polymers of the present invention containing GHG-type interdigitating rotaxanes in their main chains, in which vinyl groups have been introduced into secondary ammonium salts, possess a self-repair mechanism based on reversible dissociation and inclusion behavior. The mechanism of self-repair in linear polymers of the present invention is shown in the following schematic diagram. [ka]

[0022] The polymers of the present invention, which contain GHG-type intercalating rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts, can control destruction (dissociation) and self-repair (inclusion), and therefore can be applied in various forms to a wide range of materials, including metal negative electrode secondary batteries, adhesives and coating materials, and recycled materials.

[0023] Examples of solvents used for dissociation or inclusion due to a change in the external environment (external stimulus) include N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and dimethylacetamide (DMAC) for dissociation, and acetonitrile, dioxane, benzene, toluene, chloroform, chlorobenzene, dichloromethane, 1,2-dichloroethane, acetone, nitromethane, sulfolane, and 3-methylsulfolane for inclusion. [Example]

[0024] EXAMPLES Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to these examples.

[0025] [Synthesis of crown ether derivatives bearing two ammonium salts] The crown ether derivative having two ammonium salts of the present invention was synthesized by the following method. The reaction steps are explained below in order. [ka]

[0026] Dibenzo-24-crown-8 (2.53 g, 5.64 mmol), trifluoroacetic acid (50 mL), and hexamethylenetetramine (4.69 g, 33.5 mmol) were placed in a 500 mL recovery flask and refluxed at 60°C for 20 hours. The mixture was then added to water (30 mL) and stirred for 1.5 hours. The reaction mixture was extracted with dichloromethane (CHCl) and washed three times with water. The organic layer was dried over anhydrous magnesium sulfate (MgSO), and the filtrate was concentrated. After concentration, the mixture was purified by filtration to obtain the desired compound DFB24C8 as a brown solid (yield: 2.63 g, 92.4%). The synthesis of compound DFB24C8 was confirmed as follows. 1 H NMR (CDCl3) δ (ppm from TMS): 9.82-9.80 (s, 2H, Ph-OC H ), 7.43-7.40 (d, 2H, Ph ), 7.38-7.36 (s, 2H, Ph), 6.93-6.90 (d, 2H, Ph), 4.23-3.84 (m, 24H, -C H 2C H 2 - O-). The chemical structure of compound DFB24C8 and its 1 The H NMR spectrum is shown in Figure 1.

[0027] DFB24C8 (2.63 g, 5.21 mmol) and hexylamine (1.33 g, 13.1 mmol) were dissolved in methanol (220 mL) and heated at 60 °C for 4 hours to obtain the desired compound BIB24C8 as a brown solid (yield 3.22 g, 92.0%). The synthesis of compound BIB24C8 was confirmed as follows. 1 H NMR (CDCl3) δ (ppm from TMS): 8.11-8.09 (s, 2H, Ph-C H =N), 7.36-7.32 (s, 2H, Ph),7.12-7.08 (s, 2H, Ph), 6.84-6.80 (d, 2H, Ph), 4.28-3.71 (m, 24H, -C H 2C H 2 - O-), 3.59-3.50 (m, 4H, CH=NC H 2-), 1.70-1.17 (m, 20H, CH3-(C H 2)4-), 0.93-0.81 (t, 6H, C H 3-(CH2)4-). The chemical structure of compound BIB24C8 and its 1 The H NMR spectrum is shown in Figure 2.

[0028] BIB24C8 (3.22 g, 4.80 mmol) and sodium borohydride (NaBH4 (0.380 g, 10.0 mmol)) were dissolved in methanol (70 mL) and stirred in an ice bath. The mixture was then heated in an oil bath at 60°C for 4 hours, extracted with dichloromethane (CHCl), washed with water, and filtered. The target compound BAB24C8 was obtained as a brown viscous liquid (yield 2.98 g, 92.0%). The synthesis of compound BAB24C8 was confirmed as follows. 1H NMR (CDCl3) δ (ppm from TMS): 6.87-6.77 (m, 6H, Ph), 4.20-4.76 (m, 24H, -C H 2C H 2 - O-), 3.71-3.66 (s, 4H, Ph-C H 2-NH-), 2.62-2.55 (t, 4H, -NH-C H 2-), 1.54-1.21 (m, 20H, CH3-(C H 2)4-), 0.94-0.82 (t, 6H, C H 3-(CH2)4-). The chemical structure of compound BAB24C8 and its 1 The H NMR spectrum is shown in Figure 3.

[0029] BAB24C8 (2.89 g, 4.28 mmol) was dissolved in methanol (80 mL), and 1N hydrochloric acid (HCl) was added until the pH became ≦2, followed by stirring at room temperature for 1 hour. Next, potassium hexafluorophosphate (KPF 6- (1.99 g, 10.7 mmol)) was added and stirred at room temperature for 1 hour. The mixture was extracted with dichloromethane (CHCl), washed with water, and filtered. The mixture was then purified by recrystallization from acetonitrile (CHCN) and a larger amount of diethyl ether, yielding the desired GHG_2PF6 as a brown solid (yield 3.30 g, 79.7%). The synthesis of compound GHG_2PF6 was confirmed as follows. 1 H NMR (DMSO-d6) δ (ppm from TMS): 7.12-6.96 (m, 6H, Ph), 4.16-3.60 (m, 24H, -C H 2C H 2 - O-), 4.08-4.03 (s, 4H, -Ph-C H 2-NH2 + -), 2.91-2.84 (t, -Ph-CH2-NH2 + -C H2-), 1.63-1.53 ​​(t, 4H, CH3-(CH2)3-C H 2-), 1.35-1.22 (m, 12H, CH3-(C H 2)3-), 0.94-0.86 (t, 6H, C H 3-). The chemical structure of the compound GHG_2PF6 and its 1 The H NMR spectrum is shown in Figure 4.

[0030] [Synthesis of GHG-type interdigitated rotaxanes containing crown ether derivatives bearing two ammonium salts] The resulting compound GHG_2PF6 was dissolved in acetonitrile as a GHG compound (compound 1), to obtain a GHG-type intercalated rotaxane (compound 2, [c2]daisy chain rotaxane) as shown in the following reaction scheme. [ka]

[0031] [GHG-type intercalated rotaxanes with vinyl groups attached to secondary ammonium salts not involved in the inclusion complex] By reacting the resulting GHG-type interdigitating rotaxane containing a crown ether derivative with two ammonium salts with a compound containing a vinyl group, we synthesized a GHG-type interdigitating rotaxane in which a vinyl group was introduced into the secondary ammonium salt that was not involved in the inclusion complex.

[0032] The reaction formula using MOI-EG (2-(2-methacryloyloxyethyloxy)ethyl isocyanate) as the compound having a vinyl group is shown below. [ka]

[0033] The GHG-type interdigitated rotaxane (0.300 g, 0.155 mmol), MOI-EG (0.324 g, 1.63 mmol), and a catalytic amount of Di-n-butyltin (IV) Dilaurate were dissolved in acetonitrile (CH3CN (3.1 mL)) and stirred at room temperature for 48 hours. The solution was then recrystallized from acetonitrile (CH3CN) and a larger amount of diethyl ether, and filtered with methanol to obtain the desired GHG-type interdigitated rotaxane as a brown solid (yield 0.316 g, 100%). The GHG-type interdigitated rotaxane with a vinyl group introduced to the secondary ammonium salt not involved in the inclusion complex was confirmed by (i) the solubility of the GHG-type interdigitated rotaxane with a vinyl group introduced to the secondary ammonium salt not involved in the inclusion complex in CD3CN. 1 H NMR spectrum, and (ii) the GHG compound in DMSO-d6 with a vinyl group introduced into a secondary ammonium salt not involved in the inclusion complex. 1 The 1 H NMR spectrum confirmed this. 1 The 1 H NMR spectrum is shown in Figure 5.

[0034] The reaction formula using AOI (2-isocyanatoethyl acrylate) as the compound having a vinyl group is shown below. [ka]

[0035] The GHG-type interdigitated rotaxane (0.700 g, 0.362 mmol), 2-isocyanatoethyl acrylate (AOI) (1.27 g, 9.05 mmol), and a catalytic amount of Di-n-butyltin (IV) Dilaurate were dissolved in acetonitrile and stirred at room temperature for 24 hours. The resulting solution was then reprecipitated with acetonitrile and a larger amount of diethyl ether, and purified by washing with ethyl acetate (EtOAc) to obtain a brown solid. The GHG-type interdigitated rotaxane with a vinyl group introduced into the secondary ammonium salt was confirmed to have been obtained by (i) the inclusion of the GHG-type interdigitated rotaxane with a vinyl group introduced into the secondary ammonium salt not involved in the inclusion complex in CD3CN. 1 H NMR spectrum, and (ii) the GHG compound in DMSO-d6 in which a vinyl group was introduced into a secondary ammonium salt not involved in the inclusion complex. 1 The 1 H NMR spectrum confirmed this. 1 The 1 H NMR spectrum is shown in Figure 6.

[0036] [Polymers containing GHG-type intercalated rotaxanes in the side chains, in which vinyl groups have been introduced into secondary ammonium salts] We used a GHG-type interdigitating rotaxane in which a vinyl group was introduced into a secondary ammonium salt as a crosslinker and radically polymerized this vinyl group with a vinyl monomer to produce a polymer with a GHG-type interdigitating rotaxane in which a vinyl group was introduced into a secondary ammonium salt as a side chain. A conceptual diagram of the polymer production of the present invention is shown below. The GHG-type interdigitating rotaxane in which a vinyl group was introduced into a secondary ammonium salt was synthesized using MOI-EG, and methyl methacrylate (MMA), 2-methoxyethyl methacrylate (MEM), and diethylene glycol monomethyl ether methacrylate (DGMEM) were used as vinyl monomers. [ka]

[0037] The GHG-type interdigitated rotaxane was dissolved in acetonitrile (CHCN) with benzophenone as vinyl monomers at a predetermined equivalent weight, and the solution was poured into a silicon mold and irradiated with UV (LED, wavelength 360 nm) for 1 hour. After washing with acetonitrile, a polymer containing the GHG-type interdigitated rotaxane in its side chain was obtained as a reddish-brown gel-like solid.

[0038] [Compression resistance measurement] The shape memory properties of the synthesized cylindrical solids were evaluated using a benchtop compression tester (MCT-1150) with the following specifications. Maximum test force capacity: 500N, Compression speed: 10 mm / min, Pressure plate (JM-X004-500N): Tip diameter 15mm, height 16mm Figure 7 shows the results of compressing the polymer containing the GHG-type interdigitated rotaxane of the present invention in its side chain, which was produced by radical copolymerization of DGMEM (vinyl monomer) with a GHG-type interdigitated rotaxane (crosslinker) in which a vinyl group was introduced into a secondary ammonium salt, at reaction feed ratios of 10:1 and 20:1, and the DGMEM homopolymer (thickness 3.5 mm, φ10 mm) at 500 N. 7, the DGMEM homopolymer showed a sudden increase in load at a compression ratio of around 40 to 50%, suggesting damage to its shape, and finally, destruction of the polymer was observed after a load of 500 N. On the other hand, the polymer (gel) obtained using the GHG-type interdigitating rotaxane of the present invention, in which a vinyl group has been introduced into a secondary ammonium salt, as a crosslinker, restored its original shape from the compressed state after a load of 500 N, regardless of the composition ratio with the vinyl monomer. This indicates that the polymer gel containing the GHG-type interdigitating rotaxane of the present invention, in which a vinyl group has been introduced into a secondary ammonium salt, in its side chains, has excellent compression properties.

[0039] [Swelling behavior] Table 1 shows the swelling degree (solvent absorption amount) of the polymer of the present invention, which was produced by radical copolymerization of DGMEM (vinyl monomer) and a GHG-type intercalating rotaxane (crosslinking agent) in which a vinyl group was introduced into a secondary ammonium salt at a reaction charge ratio of 10:1, in acetonitrile (CH3CN) and dimethylformamide (DMF). [Table 1] As shown in Table 1, the polymer produced by radical copolymerization of DGMEM and a GHG-type intercalated rotaxane in which a vinyl group was introduced into a secondary ammonium salt at a molar ratio of 10:1 exhibited swelling behavior (solvent absorption) approximately 1.5 times higher in DMF than in acetonitrile. Although acetonitrile and DMF are both aprotic polar solvents with approximately the same dielectric constant, the state of the inclusion structure of the polymer of the present invention in acetonitrile and DMF differs. Generally, the inclusion structure of the rotaxane is maintained in acetonitrile, so the crosslink density of the network itself does not decrease. However, in DMF, DMF coordinates to the ammonium salt in the inclusion structure of the rotaxane, dissociating the inclusion structure and decreasing the crosslink density, which is thought to improve the swelling. Figure 8 shows a schematic representation of the swelling behavior of the polymer of the present invention in acetonitrile and DMF.

[0040] Table 2 shows the swelling degree in DMF of the polymers of the present invention produced by radical copolymerization of DGMEM (vinyl monomer) with a GHG-type intercalating rotaxane (crosslinking agent) in which a vinyl group has been introduced into a secondary ammonium salt at reaction charge ratios of 10:1 and 5:1. [Table 2] Table 2 shows the swelling behavior (solvent absorption) in DMF of the polymers of the present invention produced by copolymerization of DGMEM with a GHG-type interdigitating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt at reaction feed ratios of 10:1 and 5:1. The polymer produced at a reaction feed ratio of 5:1, which has a higher crosslink density, exhibited a higher degree of swelling than the polymer produced at a reaction feed ratio of 10:1. Generally, when polymerized using the same combination of monomer and crosslinker, a lower proportion of crosslinker exhibits a higher degree of swelling. However, when polymers were produced using the present GHG-type interdigitating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt as a crosslinker, polymers with a higher crosslink density exhibited a higher degree of swelling. This is thought to be due to the dissociation of the inclusion structure in DMF, as shown in Figure 8, resulting in a more significant change (decrease) in crosslink density at the 5:1 molar ratio, which contains a higher proportion of the rotaxane inclusion structure. In this way, the crosslinking density (swelling degree) of the polymer of the present invention can be reversibly controlled by changing the type of solvent or the molar ratio of the solvent used in the gel state, and it is possible to impart not only high compression resistance but also high swelling properties.

[0041] [Linear polymers containing GHG-type intercalated rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts] We used a GHG-type interdigitating rotaxane with a vinyl group introduced into a secondary ammonium salt as an electrophile, and by subjecting the vinyl group to a Michael addition reaction with a dithiol, we produced a linear polymer containing a GHG-type interdigitating rotaxane with a vinyl group introduced into a secondary ammonium salt in the main chain. The conceptual diagram of the production is shown below. 3,6-dioxa-1,8-octanedithiol (DODT) is used as an example of a dithiol. [ka]

[0042] A GHG-type interdigitated rotaxane (electrophile, 0.446 g, 0.225 mmol) with vinyl groups introduced into the secondary ammonium salt was dissolved in acetonitrile (CH3CN (2 mL)) and triethylamine (0.01 g, 0.0988 mmol) and 3,6-dioxa-1,8-octanedithiol (DODT, 0.0125 g, 0.0256 mmol) were added and reacted at 70 °C. Figure 9 shows the formation of a linear polymer ([c2]daisy-chain rotaxane-co-DODT polymer) containing a GHG-type interdigitated rotaxane with vinyl groups introduced into the secondary ammonium salt in the main chain. (i) The formation of a GHG-type interdigitated rotaxane with vinyl groups introduced into the secondary ammonium salt not involved in the inclusion complex in CD3CN. 1 H NMR spectrum, (ii) DODT 1 H NMR spectrum, and (iii) the obtained DODT polymer ([c2]daisy-chain rotaxane-co-DODT polymer). 1 This was confirmed by H NMR spectroscopy. Comparing the spectra (i) and (iii) in Figure 9 reveals that the peak attributable to the terminal double bond of the rotaxane decreases around 6 ppm, indicating the progress of polymerization. Comparing the spectra (ii) and (iii) reveals that the peak splits around 2–3 ppm due to the addition of thiol to the double bond. This confirms the production of a linear polymer ([c2]daisy-chain rotaxane-co-DODT polymer) containing a GHG-type intercalated rotaxane in the main chain, in which a vinyl group has been introduced into the secondary ammonium salt.

[0043] [Network polymers containing GHG-type interdigitating rotaxanes in the main chain, in which vinyl groups have been introduced into secondary ammonium salts] Using a GHG-type interdigitating rotaxane with a vinyl group introduced into a secondary ammonium salt as an electrophile, we synthesized a network polymer containing a GHG-type interdigitating rotaxane with a vinyl group introduced into a secondary ammonium salt in the main chain by subjecting this vinyl group to a Michael addition reaction with a tetrathiol. The conceptual diagram of the synthesis is shown below. Pentaerythritol tetrakis(PTMA) is used as an example of the tetrathiol. [ka]

[0044] A GHG-type interdigitated rotaxane (0.249 g, 0.126 mmol) in which a vinyl group had been introduced into a secondary ammonium salt was dissolved in acetonitrile (2 mL) in a sample tube. Triethylamine (catalyst) and PTMA (pentaerythritol tetrakis(III), 0.0340 g, 0.0690 mmol) were added as a tetrathiol and reacted at 70 °C for several hours, followed by drying in a fume hood. A schematic diagram of the resulting network polymer ([c2]daisy-chain rotaxane-co-PTMA polymer) containing a GHG-type interdigitated rotaxane in which a vinyl group had been introduced into a secondary ammonium salt in the main chain is shown below. [ka]

[0045] The glass transition temperatures of the linear polymer ([c2]daisy-chain rotaxane-co-DODT polymer) and network polymer ([c2]daisy-chain rotaxane-co-PTMA polymer) containing the GHG-type intercalated rotaxane in the main chain, in which a vinyl group was introduced into the secondary ammonium salt obtained as described above, were measured by DSC. The measurement results are shown in Figure 10. Figure 10 shows that the linear polymer of the present invention ([c2]daisy-chain rotaxane-co-DODT polymer) and the network polymer of the present invention ([c2]daisy-chain rotaxane-co-PTMA polymer) both had clear glass transition temperatures of 72.2°C and 70.1°C, respectively, confirming that the obtained compounds were polymers.

[0046] [Dissolution and swelling behavior] The dissolution and swelling behavior of a linear polymer of DODT and a GHG-type interdigitated rotaxane ([c2]daisy-chain rotaxane-co-DODT polymer) and a network polymer of PTMA and a GHG-type interdigitated rotaxane ([c2]daisy-chain rotaxane-co-PTMA polymer) in organic solvents was investigated as follows. As shown in Figure 11, both the [c2]daisy-chain rotaxane-co-DODT polymer and the [c2]daisy-chain rotaxane-co-PTMA polymer were soluble in acetonitrile (CH3CN) and dimethylformamide (DMF) at a concentration of approximately 0.5 M (GHG_2PF6 equivalent) and formed sol or gel forms. Also, [c2]daisy-chain rotaxane-co-DODT polymer (iii) in CD3CN 1 H NMR measurement results and (IV) in DMSO-d6 1The results of H NMR are shown in Figure 12. Comparing the spectrum of (iii) with that of (IV), the proton peak derived from the crown ether in (IV) becomes sharper, and the peak near 7 ppm becomes sharper overall. This suggests that the [c2]daisy-chain rotaxane-co-DODT polymer is in a dissociated state in DMSO-d6. A schematic diagram of the inclusion and dissociation states of the [c2]daisy-chain rotaxane-co-DODT polymer of the present invention is shown in Figure 13. In DMSO-d6, the [c2]daisy-chain rotaxane-co-DODT polymer of the present invention is thought to be in the dissociated state shown at the bottom of Figure 13. Furthermore, [c2]daisy-chain rotaxane-co-PTMA in CD3CN and DMSO-d6 1 The results of H NMR are shown in Figure 14. In CD3CN, broadening of the overall peak due to polymerization and multiple fragmentation behavior at 3-4 ppm, which is unique to the crown ether unit of the rotaxane structure of the present invention, were observed. These observations suggest that the polymer of the present invention maintains a network structure due to the inclusion structure in CD3CN, resulting in gelation. In deuterated DMSO-d6, the broad peak near 7 ppm becomes sharper, and the proton peaks near the ammonium salt and at 3-4.5 ppm, which are derived from the crown ether, become sharper. Furthermore, the polymer appears to be in a solution (sol) state, suggesting that the network structure of the polymer of the present invention has collapsed and dissociated.

[0047] [Self-repairability] [c2] The self-healing properties of Daisy-chain rotaxane-co-PTMA polymer were evaluated by utilizing its reversible inclusion behavior. As shown in Figure 15, when a dry sample of the [c2] Daisy-chain rotaxane-co-PTMA polymer obtained as described above was cut with a metal spatula, the cut surface was wetted with CH3CN, and the polymer was bonded at room temperature (25°C). The cut surface disappeared within 10 minutes, confirming the polymer's self-repairing ability.

[0048] [Compression test] A 0.68 g gel (polymer content 62 wt%, acetonitrile 38 wt%) prepared from a network polymer ([c2]daisy-chain rotaxane-co-PTMA polymer) containing a GHG-type interdigitating rotaxane in the main chain, in which a vinyl group was introduced into a secondary ammonium salt, was placed in a silicone mold (1.0 cm diameter x 0.7 mm thickness) and molded into a test specimen. Compression tests were performed using the following equipment and measurement conditions to measure the stress (load) and strain (displacement) at which the gel broke. The broken gel was then placed in a silicone mold at room temperature, remolded with acetonitrile, and subjected to the compression test again. Furthermore, measurements were performed three times by repeating the remolding process. Equipment: Tension / compression testing machine FORCE TESTER MCT-1150 (manufactured by A&D Co., Ltd.) Measurement conditions: Load speed 10mm / min, upper load limit 500N, measurement temperature 25℃ The results of the compression test are shown in Figure 16. Similar stress-strain curves were obtained from the first to third measurements. This suggests that when a gel prepared from a network polymer containing a GHG-type interdigitated rotaxane in the main chain, in which a vinyl group was introduced into a secondary ammonium salt ([c2]daisy-chain rotaxane-co-PTMA polymer) was broken, no bond decomposition occurred other than the dissociation of the interdigitated rotaxane structure, and the interdigitated rotaxane structure was reconstructed (inclusion), returning the gel to its original state. [Industrial Applicability]

[0049] By using GHG-type interdigitating rotaxanes, in which vinyl groups have been introduced into secondary ammonium salts, as crosslinkers and examining combinations with various vinyl monomers, it is possible to synthesize network polymers that not only have high compression resistance but also have a wide range of adjustable physical properties, and these are also easy to synthesize. Furthermore, for the self-healing network polymers obtained by using GHG-type interdigitating rotaxanes, in which vinyl groups have been introduced into secondary ammonium salts, as electrophiles, the simultaneous use of various thiols or versatile electrophiles can change the tolerance to external stimuli and enable the control of various physical parameters, leading to a wide range of future applications.

Claims

1. A GHG-type interdigitating rotaxane represented by chemical formula (1) in which a vinyl group is introduced into a secondary ammonium salt that is not involved in the inclusion. 【Chemistry 1】

2. A polymer containing, in its side chain, a GHG-type intercalating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt according to claim 1.

3. A method for producing the polymer according to claim 2, wherein the GHG-type intercalating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt according to claim 1 is used as a crosslinking agent, and the method comprises radical polymerization reaction with a vinyl group-containing monomer.

4. A polymer containing, in its main chain, a GHG-type intercalating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt according to claim 1.

5. The polymer of claim 4 , wherein the polymer is self-healing.

6. The polymer of claim 4 , wherein the polymer is a linear polymer.

7. The polymer of claim 4 , wherein the polymer is a network polymer.

8. A method for producing the polymer according to claim 4, wherein the GHG-type intercalating rotaxane in which a vinyl group has been introduced into the secondary ammonium salt according to claim 1 is used as an electrophilic agent, and the rotaxane is subjected to a Michael addition reaction with a thiol compound.

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