Supramolecular polymer material based on pseudorotaxane structure as well as preparation method and application of supramolecular polymer material

Abstract

The invention discloses a supramolecular polymer material based on a pseudorotaxane structure as well as a preparation method and application of the supramolecular polymer material, a matrix of the supramolecular polymer material is polydisulfide, a macrocyclic main body is complexed on a side chain of the polydisulfide, and the macrocyclic main body is a macrocyclic containing an electron-rich cavity structure. A quasi rotaxane structure is constructed by complexing a column [5] arene cavity and a lipoic acid alkyl chain, and the polymer material is endowed with excellent shear hardening performance by utilizing time dependence of dynamic dissociation of quasi rotaxane. Under relatively low-speed impact, pillararene slowly slips off from a side chain, and under high-speed impact, dissociation behaviors cannot be completed in time, so that a subject-object topological structure becomes a rigid site, impact force is dispersed to a nearby area in a spatial scale to prevent stress concentration, instantaneous impact force is dispersed in a time scale due to hysteresis of subject-object dissociation, and thus, the stability of the subject-object dissociation is improved. And the stress peak value is effectively reduced, so that the purpose of impact resistance protection is achieved.

Description

Technical Field

[0001] This invention belongs to the field of supramolecular polymer materials, specifically relating to a supramolecular polymer material based on a quasi-rotaxane structure, its preparation method, and its application. Background Technology

[0002] Shear-hardening materials are smart viscoelastic polymers that exhibit excellent flexibility at low shear rates, but their storage modulus and stiffness increase exponentially when the shear rate exceeds a critical value. This superior rate responsiveness perfectly meets the lightweight, flexible, and impact-resistant requirements of wearable devices and protective armor, showing broad application prospects. Materials such as Kevlar fiber, polyurethane, lignin, and polyboron dimethylsiloxane have been extensively studied for preparing shear-hardening composites; however, the complex structural design of these materials, their failure after impact, and their inability to degrade and recycle limit their applications.

[0003] Hardened shear materials based on supramolecular forces offer a new approach to solving the aforementioned problems. These materials not only maintain excellent flexibility and impact resistance but also possess self-healing and recyclable properties. This characteristic allows protective equipment to quickly recover its performance after being subjected to impact, significantly improving the sustained combat capability of individual soldiers and reducing production costs and energy consumption. However, current supramolecular impact resistance strategies mainly rely on sacrificial bonds (i.e., non-covalent bonds such as ionic bonds, hydrogen bonds, and electrostatic interactions) to dissipate energy. While these sacrificial bonds provide a pathway for energy dissipation, their breakage often disrupts the network structure, easily leading to a significant decline in mechanical properties during continuous cyclic loading.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a supramolecular polymer material based on a quasi-rotaxane structure, its preparation method, and its application. The shear hardening property is achieved through the dynamic dissociation behavior of the quasi-rotaxane structure to achieve impact resistance. This supramolecular polymer based on the quasi-rotaxane structure exhibits high modulus and stiffness under high-speed impact, while possessing good flexibility under low-speed impact, thus providing good protection without hindering human activities.

[0006] To achieve the above objectives, the present invention provides a supramolecular polymer material based on a quasi-rotaxane structure. The matrix of the supramolecular polymer material is a polydisulfide, and a macrocyclic host is complexed on the side chain of the polydisulfide. The macrocyclic host is a macrocycle containing an electron-rich cavity structure, and the molar ratio of the disulfide to the macrocyclic host is 1:0.001~0.01.

[0007] Preferably, the supramolecular polymer material uses thioctic acid, which has a dynamic disulfide bond capable of ring opening, as a guest, and constructs a quasi-rotaxane structure by complexing the alkyl chain of the disulfide with the cavity of the macrocyclic host.

[0008] The structural formula of the polydisulfide is shown in Formula II: Preferably, the macrocyclic body is selected from columnar aromatic hydrocarbons [5].

[0009] More preferably, the column[5] aromatic hydrocarbon is selected from brominated column[5] aromatic hydrocarbons.

[0010] More preferably, the structure of the brominated columnar aromatic hydrocarbon [5] is shown in Formula I: Preferably, the molar ratio of thioctic acid to the macrocyclic host is 1:0.008.

[0011] A second objective of this invention is to provide a method for preparing the supramolecular polymer material based on the quasi-rotaxane structure, the method comprising: The disulfide was reacted with the macrocyclic host by heating at 140 °C. After the reaction was completed, the mixture was cooled to room temperature to obtain a supramolecular polymer based on a quasi-rotaxane structure.

[0012] Preferably, the molar ratio of the disulfide to the macrocyclic body is 1:0.001~0.01.

[0013] Preferably, the heating reaction time is 10 min.

[0014] Preferably, the room temperature is 25~30℃.

[0015] A third objective of this invention is to provide the application of the supramolecular polymer material based on the quasi-rotaxane structure in impact-resistant materials.

[0016] The supramolecular polymer materials based on quasi-rotaxane structures, their preparation methods, and applications of the present invention have the following advantages: (1) This invention uses a macrocycle with an electron-rich cavity structure and thioctic acid with a dynamic disulfide bond that can open the ring as a guest. The polyquasi-rotaxane structure is constructed by complexing the columnar aromatic cavity with the alkyl side chain of polythioctic acid. The time dependence of quasi-rotaxane complexation and dissociation gives the polymer material excellent shear hardening properties. Under relatively low-speed impact, the columnar aromatics slowly slide off the side chain. Under high-speed impact, the dissociation behavior cannot be completed in time, making the host-guest topology a rigid site and dispersing the impact force to the nearby area on a spatial scale to prevent stress concentration. The hysteresis of host-guest dissociation disperses the instantaneous impact force on a time scale, effectively reducing the stress peak, thereby achieving the purpose of impact protection.

[0017] (2) The supramolecular polymer based on the quasi-rotaxane structure of this invention has time-responsiveness, excellent shear hardening properties, adhesive properties, self-healing, antibacterial properties, and is simple and inexpensive. It has a five-membered ring-opening polymer product containing dynamic disulfide bonds as the main chain, and non-covalent crosslinking with side chain carboxylic acids to ensure the self-healing and adhesive properties of the material. The unique slip ring structure formed by columnar aromatics and polythiooctanoic acid alkyl side chains creates a clever energy dissipation mechanism. By bypassing the loss mechanism that sacrifices existing covalent and non-covalent bonds, the integrity of the polymer network under load is protected, thereby ensuring the stability and reliability of mechanical properties. Under the above strategy, the strain and stress of the polymer can be recovered to more than 90% of the initial value within 30 min after complete cutting, and the Young's modulus increases to 1640% of the original value when the impact speed increases from 0.2 mm / min to 100 mm / min, and the energy absorption increases to 864% of the original value.

[0018] (3) The supramolecular polymer based on the quasi-rotaxane structure of the present invention can adjust the polymer modulus and stiffness in real time by controlling the impact rate, and can recover in a short time after being subjected to impact failure, and can be used as an impact protection material; (4) The method of the present invention uses a one-pot preparation method, which is simple, the raw materials are readily available, the cost is low, and it is green, environmentally friendly and non-toxic. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the principle of shear hardening of supramolecular polymer materials based on quasi-rotaxane structures according to the present invention.

[0020] Figure 2 The NMR spectrum of the supramolecular polymer prepared in Example 1 of this invention is shown.

[0021] Figure 3 The image shows the infrared spectrum of the supramolecular polymer prepared in Example 1 of this invention.

[0022] Figure 4This is a cold flow property diagram of the supramolecular polymer prepared in Example 1 of the present invention.

[0023] Figure 5 The tensile stress-strain diagram (A), Young's modulus, and toughness results (B) of the supramolecular polymers prepared in Examples 1-5 of this invention are shown.

[0024] Figure 6 The image shows the dynamic frequency shear scan curve of the supramolecular polymer prepared in Example 1 of this invention.

[0025] Figure 7 The diagram shows the compression stress-strain curves (A) of the supramolecular polymer prepared in Example 1 of this invention at different compression rates and the effect of different compression rates on Young's modulus (B).

[0026] Figure 8 The image shows the impact force absorption curves of the supramolecular polymer prepared in Example 1 of this invention for steel balls of different masses.

[0027] Figure 9 The diagram shows the self-healing properties of the supramolecular polymer prepared in Example 1 of this invention; (A) a self-healing photograph; (B) stress-strain curves at different repair times; and (C) stress-strain recovery rates at different repair times.

[0028] Figure 10 The adhesion properties of the supramolecular polymer prepared in Example 1 of this invention are shown.

[0029] Figure 11 The antibacterial effects of the supramolecular polymer prepared in Example 1 of this invention against Staphylococcus aureus (A), Escherichia coli (B), and methicillin-resistant Staphylococcus aureus (C) at 24, 48, and 72 h are shown. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted that: Unless otherwise specified in the examples, standard conditions or conditions recommended by the manufacturer should be followed. Instruments whose manufacturers are not specified are all commercially available products. Raw materials and reagents whose manufacturers are not specified are all commercially available goods or can be prepared using known methods.

[0032] In this invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are used only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0033] The features mentioned in this invention can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification, provided that there is no contradiction in the combination of these features. Each feature disclosed in the specification can be replaced by any alternative feature that provides the same, equivalent, or similar purpose. Therefore, unless otherwise specified, the disclosed features are merely general examples of equivalent or similar features.

[0034] This invention provides a supramolecular polymer material based on a quasi-rotaxane structure, its preparation method, and its application. The shear hardening properties are achieved through the complexation and dissociation behavior of the quasi-rotaxane structure to achieve impact resistance. The preparation method of this supramolecular polymer material includes: The disulfide monomer and the macrocyclic host were reacted by heating at 140 °C. After the reaction was completed, the mixture was cooled to room temperature to obtain a supramolecular polymer based on a quasi-rotaxane structure.

[0035] According to a preferred embodiment of the present invention, the disulfide is selected from lipoic acid.

[0036] This invention, based on a host-guest complex slip ring structure, allows for energy dissipation through the relative sliding of the macroring body and the complexing chain segments. This provides an additional mechanism for stress dissipation beyond chain unfolding and stretching, preventing the degradation of mechanical properties during loading caused by the breaking of sacrificial bonds. See also... Figure 1 This invention utilizes natural small-molecule thioctic acid with carboxyl groups and a macrocyclic host with an electron-rich cavity structure. By designing a quasi-rotaxane structure, a disulfide-bonded polymer-based supramolecular polymer with shear-hardening properties is obtained. The dynamic disulfide bonds endow the material with excellent self-healing and antibacterial properties, while the quasi-rotaxane structure formed by the complexation of the macrocyclic host and alkyl side chains endows the material with excellent shear-hardening properties, effective energy dissipation, and stress dispersion mechanisms.

[0037] In a further preferred embodiment, the macrocyclic host is selected from brominated columnar aromatic hydrocarbons [5], with the chemical structural formula shown in Formula I.

[0038] In a further preferred embodiment, the molar ratio of the disulfide to the brominated columnar [5] aromatic hydrocarbon is 1:0.001~0.01.

[0039] In a further preferred embodiment, the room temperature is 25~30℃.

[0040] The following examples illustrate in detail the supramolecular polymer material based on the quasi-rotaxane structure, its preparation method, and its applications provided by the present invention.

[0041] Example 1 Lipoic acid (500.0 mg, 2.4 mmol) and brominated aromatic hydrocarbons [5] (32.6 mg, 0.02 mmol) were weighed separately, placed in a glass bottle, and stirred at 140 °C for 10 min until they were evenly mixed. The mixture was poured into a mold and cooled to room temperature to obtain a supramolecular polymer.

[0042] Examples 2-5 The method is basically the same as that in Example 1, except that the molar ratio of bromo-coated[5] aromatic hydrocarbon to thioctic acid in Examples 2, 3, 4 and 5 is 0.001:1, 0.003:1, 0.005:1 and 0.01:1, respectively.

[0043] Experimental Example 1: Structural Characterization The supramolecular polymer prepared in Example 1 of this invention was subjected to NMR spectroscopy, and the results are as follows: Figure 2 As shown, the supramolecular polymer was dissolved in deuterated DMSO. By analyzing the 1H NMR spectrum, it was found that the polymer still existed as a linear polythiooctanoic acid structure in the deuterated DMSO. Compared with the columnar aromatic structure, the chemical shifts of hydrogens 2, 3, and 4 on the columnar aromatic structure of the polymer were shifted. This indicates that even in the strongly polar solvent DMSO, there is still a host-guest interaction between the columnar aromatic cavity and the alkyl side chain of polythiooctanoic acid.

[0044] Infrared spectroscopy analysis was performed on the supramolecular polymer prepared in Example 1 of this invention, and the results are as follows: Figure 3 As shown, the carbonyl characteristic peak in the supramolecular polymer did not undergo a significant shift, ruling out the possibility of shear hardening caused by non-covalent interactions of the carboxyl groups. Combined with 1H NMR spectroscopy, it was confirmed that the cavity structure of the pillar aromatic hydrocarbon and the alkyl side chain of the polythiooctanoic acid formed a host-guest interaction.

[0045] Experiment Example 2 Performance Testing 1. Cold flow property test The supramolecular polymer prepared in Example 1 of this invention was subjected to cold flow property testing, and the results are as follows: Figure 4 As shown, supramolecular polymers exhibit a significant cold flow phenomenon at room temperature (30 °C).

[0046] 2. Tensile test Tensile tests were performed on the supramolecular polymers prepared in Examples 1-5 of this invention, and the results are as follows: Figure 5As shown, considering Young's modulus, yield stress, elongation at break and fracture stress, the polymer has the best mechanical properties when the molar ratio of thioctic acid to aromatic hydrocarbon [5] is 1:0.008. Therefore, 1:0.008 is determined to be the optimal ratio, and subsequent tests are conducted based on this ratio.

[0047] 3. Rheological dynamic frequency shear scan test The supramolecular polymer prepared in Example 1 of this invention was subjected to rheological dynamic frequency shear scanning tests, and the results are as follows: Figure 6 As shown, at room temperature (25 °C), the polymer transitions from a dissipative state at low frequencies to a glassy state at high frequencies, indicating that the polymer exhibits shear hardening properties.

[0048] 4. Compression test The supramolecular polymer prepared in Example 1 of this invention was subjected to compression tests at different rates, and the results are as follows: Figure 7 As shown in Figure A, the compressive stress increases with increasing compression rate. Figure 7 As shown in Figure B, the mechanical properties of the material change significantly as the strain rate increases from 0.2 mm / min to 100 mm / min. Young's modulus increases significantly from 0.1 MPa to 1.7 MPa, an increase of 1600%. At compression rates below 10 mm / min, the change in Young's modulus is relatively gradual, exhibiting low-modulus yield characteristics. However, after compression at a rate of 100 mm / min, the modulus increases significantly to 1.7 MPa, demonstrating a significant hardening response. Furthermore, the energy dissipation capacity increases from 0.17 MJ / m at 0.2 mm / min. 3 Increased to 1.48 MJ / m at 100 mm / min 3 This demonstrates that the supramolecular polymer exhibits excellent energy absorption characteristics under rapid compression.

[0049] 5. Impact protection test Impact protection tests were conducted on the supramolecular polymer prepared in Example 1 of this invention. The results are shown in Figure 8, which prove that the supramolecular polymer has impact resistance properties. The test on the 1 mm thick supramolecular polymer at a drop height of 0.8 m shows that when subjected to impacts of 16 g, 32 g and 50 g steel balls, respectively, the material exhibits an impact force attenuation rate of 40%, 25% and 11% compared with the blank group without polymer material. This indicates that the supramolecular polymer can quickly suppress the generated shock wave.

[0050] 6. Self-repair test The supramolecular polymer prepared in Example 1 of this invention was subjected to a self-healing test, and the results are as follows: Figure 9 As shown, this indicates that supramolecular polymers possess self-healing properties, such as... Figure 9As shown in Figure A, the surface scratches of the polymer essentially disappeared after healing for 30 minutes at room temperature, and no breakage occurred at the notch during stretching; as Figure 9 As shown in Figure B, the stress-strain curves are obtained at a tensile rate of 100 mm / min under different healing times; Figure 9 As shown in Figure C, at room temperature, the polymer can achieve a strain recovery rate of 77% and a strength recovery rate of 70% within 10 minutes. When the healing time is extended to 30 minutes, the recovery rate is further increased to 94%, demonstrating a rapid and efficient repair capability.

[0051] 7. Adhesion test The supramolecular polymer prepared in Example 1 of this invention was subjected to an adhesion test, and the results are as follows: Figure 10 As shown, the supramolecular polymer exhibits adhesive properties. The results show that the polymer demonstrates significant selective adhesion to hydrophilic substrates. At a tensile rate of 50 mm / min, the adhesion strength to iron sheets and quartz glass is 3.19 MPa and 2.8 MPa, respectively, while the adhesion strength to the hydrophobic surface PMMA is only 0.55 MPa.

[0052] 8. Long-term antibacterial test Long-term antibacterial experiments were conducted on the supramolecular polymer prepared in Example 1 of this invention. 20 mg of the supramolecular polymer and 18.72 mg of polythiooctanoic acid were dissolved in 1 mL of a 10% concentration solution. 6 The samples were incubated in CFU / mL bacterial suspension, with pure bacterial suspension without the added material serving as a blank control. All samples were incubated at 37 ℃ for 24 h, 48 h, and 72 h, respectively, and the absorbance at 600 nm was measured using a microplate reader. The antibacterial efficiency of the material at different incubation time points was quantitatively analyzed by comparing the absorbance changes between the experimental and control groups.

[0053] The results are as follows Figure 11 As shown, polythioctic acid and supramolecular polymers all exhibited sustained antibacterial effects against three types of bacteria, with antibacterial rates exceeding 90% within 72 hours, indicating that supramolecular polymers possess long-lasting antibacterial properties.

[0054] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A supramolecular polymer material based on a quasi-rotaxane structure, characterized in that, The matrix of this supramolecular polymer material is polydisulfide, with a macrocyclic host complexed on the side chain of the polydisulfide. The macrocyclic host is a macrocycle containing an electron-rich cavity structure, and the molar ratio of the disulfide to the macrocyclic host is 1:0.001~0.

01.

2. The supramolecular polymer material based on a quasi-rotaxane structure according to claim 1, characterized in that, This supramolecular polymer material uses thioctic acid, which has a dynamic disulfide bond capable of ring opening, as a guest. It constructs a quasi-rotaxane structure by complexing the macrocyclic host with the alkyl chain of thioctic acid.

3. The supramolecular polymer material based on a quasi-rotaxane structure according to claim 2, characterized in that, The macrocyclic body is selected from columnar aromatic hydrocarbons [5].

4. The supramolecular polymer material based on a quasi-rotaxane structure according to claim 3, characterized in that, The column[5] aromatic hydrocarbons are selected from brominated column[5] aromatic hydrocarbons.

5. The supramolecular polymer material based on a quasi-rotaxane structure according to claim 4, characterized in that, The structural formula of the brominated columnar [5] aromatic hydrocarbon is shown in Formula I: 。 6. The supramolecular polymer material based on a quasi-rotaxane structure according to claim 1, characterized in that, The molar ratio of the disulfide to the macrocyclic body is 1:0.

008.

7. The method for preparing supramolecular polymer materials based on quasi-rotaxane structures as described in any one of claims 1 to 6, characterized in that, The method includes: The disulfide was reacted with the macrocyclic host by heating at 140 °C. After the reaction was completed, the mixture was cooled to room temperature to obtain a supramolecular polymer based on the quasi-rotaxane structure. The molar ratio of the disulfide to the macrocyclic body is 1:0.001~0.

01.

8. The preparation method according to claim 7, characterized in that, The heating reaction time is 10 min.

9. The preparation method according to claim 7, characterized in that, The room temperature is 25~30℃.

10. The application of supramolecular polymer materials based on quasi-rotaxane structures as described in any one of claims 1 to 6 in impact-resistant materials.

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