A dynamically covalent adaptive polyurethane network composite material, and a preparation method and application thereof

Abstract

The present application relates to a kind of dynamic covalent adaptation polyurethane network composite material and its preparation method and application, the present application will have endogenous catalysis four-arm dynamic unit into polyurethane network, to give material superior mechanical properties and room temperature self-healing performance, isocyanate is selected as hard segment, small molecule dihydric alcohol is selected as hard segment, improve the stability of material, soft segment adopts macromolecular dihydric alcohol, ionic liquid has good compatibility, so that material has high transparency, tensile property and elasticity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polyurethane materials, and particularly relates to a dynamic covalent adaptive polyurethane network composite material and a preparation method and application thereof. BACKGROUND

[0002] In the current century, driven by the principle of circular economy, the sustainability of the polymer industry has become an important challenge. To solve this problem, cross-linked polymers with dynamic covalent bonds, namely covalent adaptive networks (CANs), have become a new type of sustainable polymer, combining the advantages of thermosets and thermoplastics. Self-healing CANs provide longer service life, more recyclable characteristics and enhanced reliability.

[0003] However, most CANs require external stimuli such as light, heat or pressure to initiate the self-repairing process. This inconvenient process limits their applications. Therefore, there is an urgent need to develop CANs that can spontaneously self-heal at room temperature. In order to achieve fast dynamic bond exchange reactions in CANs and allow self-healing at low temperatures, various mechanisms are usually employed to lower the bond energy, including steric hindrance, coordination and other electronic effects, as well as external catalysts such as acids, transition metals or nucleophilic catalysts. But the aging of catalysts significantly shortens the life of these materials. On the other hand, the presence of covalent cross-linking units enhances the rigidity and stability of CANs, but also hinders the flowability and rearrangement ability of the network. In order to enhance the self-healing ability, the cross-linking density is often reduced. This often comes at the expense of the mechanical properties of the material. Therefore, there is an urgent need for new methods to simultaneously improve the self-healing ability and mechanical properties of CANs.

[0004] The application of fibers has evolved and expanded throughout the trajectory of human society, leading to the diversification and complexity of fiber processes. Fibers can be made into fabrics or textiles, which have the flexibility of design. As a result, fibers play a key role in both traditional textiles and emerging electronic textiles. Common fibers are primarily composed of thermoplastic materials, such as co-polyesters, polyesters, polypropylenes, polyethylenes, and polyamides. Thermoplastic polymers are the primary material for melt spinning, however, thermoplastic fibers generally have inferior elasticity, strength, and solvent resistance compared to thermoset fibers. However, thermoset polymers lack the inherent ability to be processed into one-dimensional materials, often requiring post-processing for curing and crosslinking, and as a result, thermoset fibers are less common. Covalent adaptive networks (CANs) contain dynamic bonds that exhibit the high mechanical performance and solvent stability characteristics of thermoset materials, as well as the processability and recyclability associated with thermoplastic materials. Furthermore, the dynamic bonds of CANs can impart the ability for thermoset polymers to be melt spun, which has led to increased interest in this area. Since the seminal report by Wudl in 2001 on thermoreversible Diels-Alder adduct networks, many other reversible reactions and polymerization methods have been developed for the synthesis of CANs. The development of CANs has progressed rapidly, but current CANs still face challenges at an industrial scale, primarily due to their incompatibility with commercial processing techniques. Most current research on CANs is limited to the preparation and reshaping of two- and three-dimensional materials, and the processing of CANs into fibers is a challenge. The fundamental issue lies in the reversibility of the dynamic bonds and the flowability of the network at processing temperatures.

[0005] Current efforts to improve the reversibility of dynamic bonds often involve various strategies to lower the bond energy, including coordination mechanisms, steric hindrance, and the use of external catalysts, including transition metals and acids. However, the lifetime of these materials is often compromised by catalyst aging. Furthermore, the inclusion of covalent crosslinking units can improve the strength and stability of CANs, but hinder the flowability and rearrangement ability of the network during processing. Increasing crosslinking density is a common method to enhance mechanical performance; however, this often comes at the expense of processability. Therefore, innovative methods to simultaneously improve the mechanical performance and processability of CANs are crucial. SUMMARY

[0006] In view of the defects of the prior art, the technical problem to be solved by the present application is to provide a dynamic covalent adaptive polyurethane network composite material and a preparation method and application thereof, in particular to an endogenous catalysis significantly promotes the exchange of dynamic bonds to construct a high-strength self-repairing dynamic covalent adaptive polyurethane network composite material and a preparation method and application thereof, so as to overcome the defects that the CANs in the prior art cannot simultaneously have good mechanical properties and room temperature self-repairing performance. In addition, it is particularly related to an endogenous catalysis significantly promotes the exchange of dynamic bonds to construct a high-strength easy-to-process dynamic covalent adaptive polyurethane network composite material and a preparation method and application thereof, so as to overcome the defects that the CANs in the prior art cannot simultaneously have good mechanical properties and processing performance.

[0007] The present application provides a kind of polyurethane, and the structural formula of the polyurethane is:

[0008]

[0009] At least one of the following is included:

[0010] Wherein R1 is the remaining group after the diisocyanate group is removed from the diisocyanate containing benzene ring or asymmetric alicyclic structure; R2 is the remaining chain segment after the hydroxyl group is removed from the macromolecular diol; R3 is the remaining molecular chain after the hydroxyl group is removed from the small molecular diol;

[0011] The x=100-1000; y=100-1000; z=100-1000.

[0012] Preferably, the diisocyanate includes the remaining group after the diisocyanate group is removed from isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate or toluene diisocyanate; the macromolecular diol includes the remaining chain segment after the hydroxyl group is removed from polyethylene glycol adipate diol, polybutylene glycol adipate diol, polyhexylene glycol adipate diol, polycarbonate diol, polytetrahydrofuran diol, polycaprolactone diol, polypropylene glycol or perfluoropolyether diol; the small molecular diol includes the remaining molecular chain after the hydroxyl group is removed from 1,4-butanediol, ethylene glycol, propylene glycol, fluorinated tetraethanol, fluorinated ethylene glycol, fluorinated propylene glycol or fluorinated butanediol.

[0013] The present application provides a kind of dynamic covalent adaptive polyurethane network composite material, and the components of the composite material include any of the polyurethane, ionic liquid.

[0014] Preferably, the ionic liquid accounts for 10-90wt% in the dynamic covalent adaptive polyurethane network composite material;

[0015] Preferably, the ionic liquid comprises one or more of the following: 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylpyridine hexafluorophosphate, and 1-ethyl-3-methylimidazolium dicyandiamide salt.

[0016] This invention provides a method for preparing the aforementioned dynamic covalently adaptive polyurethane network composite material, comprising:

[0017] A diisocyanate containing a benzene ring or asymmetric alicyclic structure, a four-arm crosslinking agent, a macromolecular diol and / or a small molecule diol, a catalyst, an ionic liquid, and a solvent are mixed and subjected to a nucleophilic addition reaction to obtain a prepolymer. Then, a crosslinking reaction is carried out to obtain a dynamically covalently adapted polyurethane network composite material.

[0018] Alternatively, a diisocyanate containing a benzene ring or asymmetric alicyclic structure, a four-arm crosslinking agent, a macromolecular diol and / or a small molecule diol, a catalyst, and a solvent can be mixed and subjected to a nucleophilic addition reaction to obtain a prepolymer. Then, an ionic liquid is added, and a crosslinking reaction is carried out to obtain a dynamically covalently adapted polyurethane network composite material.

[0019] The diisocyanate includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate;

[0020] Preferably, the four-arm crosslinking agent comprises diaminoacetaldehyde oxime;

[0021] Preferably, the ionic liquid comprises one or more of the following: 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylpyridine hexafluorophosphate, and 1-ethyl-3-methylimidazolium dicyanamide salt.

[0022] Preferably, the catalyst comprises one or more of dibutyltin dilaurate, stannous octoate, and triethylamine; the solvent comprises one or more of THF, Acetone, DMAC, DMSO, and DMF.

[0023] Preferably, the macromolecular diol has a molecular weight of 600-5000; the small molecule diol has a molecular weight of 100-500.

[0024] The macromolecular diol is a polyester diol.

[0025] Preferably, the macromolecular diol includes polyethylene adipate diol, polybutylene adipate diol, polyhexane adipate diol, polycarbonate diol, polytetrahydrofuran diol, polycaprolactone diol, polypropylene glycol, or perfluoropolyether diol; the small molecule diol includes 1,4-butanediol, ethylene glycol, propylene glycol, fluorinated tetraethanol, fluorinated ethylene glycol, fluorinated propylene glycol, or fluorinated butylene glycol.

[0026] Preferably, the molar ratio of the diisocyanate containing a benzene ring or asymmetric alicyclic structure to the diol is 10:4 to 10:6; the molar ratio of the diisocyanate containing a benzene ring or asymmetric alicyclic structure to the four-arm crosslinking agent is 10:1 to 10:4; the ratio of the diisocyanate containing a benzene ring or asymmetric alicyclic structure to the solvent is (15-40) mmol:(3-10) mL; the molar ratio of the macromolecular diol to the small molecule diol is 1:3 to 5:1; and the molar ratio of the macromolecular diol to the four-arm crosslinking agent is (1-8):(1-5).

[0027] The polyurethane prepolymer or a mixture of prepolymer and ionic liquid is poured into a mold and further crosslinked at high temperature, then dried.

[0028] Preferably, the nucleophilic addition reaction is carried out at a temperature of 60-100°C for a time of 15-24 hours.

[0029] Preferably, the crosslinking temperature is 60-100℃ and the time is 24-48h.

[0030] The present invention provides a material, which is a fiber, a membrane, or a woven fabric; wherein the fiber comprises the fiber of the dynamically covalently adapted polyurethane network composite material; the membrane comprises the membrane of the dynamically covalently adapted polyurethane network composite material; and the woven fabric comprises a woven fabric of the fibers of the dynamically covalently adapted polyurethane network composite material.

[0031] A method for preparing fibers containing a dynamically covalently adapted polyurethane network composite material includes: preparing the composite material using a 3D printing system; loading the dynamically covalently adapted polyurethane network composite material into an extrusion cylinder equipped with a temperature controller; heating it at 100-150°C; and then extruding it at a rate of 2-400 m / min. -1 The winding speed collects the fibers.

[0032] Because the crosslinking agent contains endogenous catalysts, it exhibits high dynamism and a correspondingly increased response rate to temperature. This results in nascent fibers possessing high melt strength within a very short cooling time, enabling them to withstand the drawing forces of high-speed winding and achieve high-speed spinning to meet the requirements of industrial spinning.

[0033] This invention provides an application of the aforementioned dynamic covalently adaptive polyurethane network composite material in the field of flexible electronics, such as electronic bracelets and flexible bulk electroluminescent devices.

[0034] Furthermore, the application of the dynamically covalently adaptive polyurethane network composite material as a conductive layer or conductor in the field of flexible electronics.

[0035] This invention, through a small molecule model, reveals that adjacent urea bonds significantly enhance the reversible reaction rate of oxime ester bonds. Utilizing highly dynamic four-arm crosslinking units containing endogenously catalyzed oxime ester groups, the material exhibits superior mechanical properties and room-temperature self-healing capabilities. Asymmetric alicyclic isocyanates are selected as the hard segments to further promote oxime ester bond exchange. Fluorinated small-molecule diols are chosen as the hard segments to improve the material's environmental stability. The soft segments, made of diols, exhibit good compatibility with ionic liquids, resulting in high transparency, tensile strength, and elasticity.

[0036] Beneficial effects

[0037] This invention designs four-armed dynamic units with endogenous catalytic activity as crosslinking points for CANs, combining the synergistic effects of electronic, spatial, and topological factors, and ensuring high crosslinking density while maintaining high network fluidity, thereby achieving excellent mechanical properties and self-healing ability at room temperature. Asymmetric alicyclic isocyanates are selected as hard segments with large-volume asymmetric structures to prevent polymer crystallization and increase polymer chain mobility, thereby further promoting the exchange of oxime ester bonds. Fluorinated small-molecule diols are selected as hard segments to improve the environmental stability of the material. The soft segments are made of polyester polyols, whose ester bonds have good compatibility with ionic liquids, giving the material high transparency, tensile strength, and elasticity. Attached Figure Description

[0038] Figure 1 This invention provides a model study of the adjacent urea bond promoting oxime ester bond exchange. (A) Exchange reaction between model compound DBD or DC and A at 25°C produces ABD or AC and D; (B) Real-time reaction of a mixture of DC and A. 1 1H NMR spectrum; (C) Real-time NMR spectrum of the mixture of DBD and A 1 (D) Conversion of molecular models with or without internal catalysts; (E) Scheme 1: The endogenous catalytic mechanism of the oxime ester group of the present invention, the key step in the reaction, also known as the rate-determining step (RDS), is carried out by generating a local negative charge on the oxime ester group.

[0039] Figure 2The i-Canogel multi-linked structure design of this invention possesses excellent mechanical properties and self-healing properties. (A) Molecular structure of i-Canogel; where x = 100-1000; y = 100-1000; z = 100-1000. (B) Schematic diagram of i-Canogel structure.

[0040] Figure 3 The mechanical properties of the i-Canogel of this invention are shown below. (A) Tensile stress-strain curve of the original i-Canogel. (B) Cyclic tensile test of the prepared i-Canogel 2:2 with gradually increasing strain. (C) Repeated cyclic tensile curve of i-Canogel 2:2 at 300% strain. The sample was then allowed to stand at 25°C for 2 hours to relax before the second cyclic tensile test. (D) The relaxation time of the i-Canogel conforms to the Arrhenius equation.

[0041] Figure 4 This invention demonstrates the self-healing properties of the i-Canogel. (A) Stress-strain curves of the original i-Canogel and the healed sample after 24 hours at room temperature. (B) Self-healing properties of i-Canogel 2:2 after 48 hours at room temperature. (C) Statistical analysis of the mechanical properties of the prepared i-Canogel 2:2. (D) Scatter plots of “toughness,” “stress,” and “self-healing time” for i-Canogel 2:2 and other room-temperature self-healing ionogels reported in the literature.

[0042] Figure 5 Electrical properties of the i-Canogel prepared for this invention. (A) Electrochemical impedance spectroscopy of i-Canogel. (B) Ionic conductivity results of i-Canogel. (C) Temperature dependence of i-Canogel ionic conductivity in the temperature range of 25-60℃. (D) Resistance of i-Canogel 2:2 as a function of temperature. (E) Resistance-strain curve of i-Canogel 2:2 strain sensor. (F) Weight retention of i-Canogel over time under ambient conditions without specific packaging.

[0043] Figure 6 (A) Scheme 2: The synthetic route of DBD of the present invention; (B) The synthesis route of N-hydroxyacetamidine, phenethyl isocyanate and DBD of the present invention. 1 HNMR spectrum.

[0044] Figure 7 For the DBD of this invention 13 C10 NMR spectrum.

[0045] Figure 8(A) Scheme 3: The synthetic route of DC in this invention; (B) The synthesis route of acetone oxime, phenethyl isocyanate, and DC in this invention. 1 HNMR spectrum.

[0046] Figure 9 For the DC of this invention 13 C10 NMR spectrum.

[0047] Figure 10 (A) Scheme 4: The synthetic route of AC in this invention; (B) The synthesis of acetone oxime, propyl isocyanate, and AC in this invention. 1 HNMR spectrum.

[0048] Figure 11 For the DC of this invention 13 C10 NMR spectrum.

[0049] Figure 12 (A) Scheme 5: Synthetic route of i-Canogel n:m of the present invention; (B) ATR-FTIR spectrum of i-Canogel n:m (n:m = 2.5:1.5, 2:2 and 1.5:2.5) of the present invention.

[0050] Figure 13 This is a swelling test for the present invention. (A) Original image of i-Canogel 2:2; (B) Image of i-Canogel 2:2 after swelling for 24 hours.

[0051] Figure 14 The ATR-FTIR spectra of [EMI][TFSI], CAN 2:2 and i-Canogel 2:2 are those of the present invention.

[0052] Figure 15 This is an enlarged ATR-FTIR spectrum of the [EMI][TFSI], CAN 2:2 and i-Canogel 2:2 of this invention.

[0053] Figure 16 This is a SEM image and energy-dispersive spectrum of the i-Canogel 2:2 of this invention. Scale bar: 500 μm.

[0054] Figure 17 Cyclic tensile curves of i-Canogel 1.5:2.5 prepared for this invention. (50 mm min) -1 )

[0055] Figure 18 Cyclic stretching curves of i-Canogel 2:2 prepared for this invention. (50 mm min) -1 )

[0056] Figure 19Cyclic tensile curves of i-Canogel 2.5:1.5 prepared for this invention. (50 mm min) -1 )

[0057] Figure 20 The tensile curve of i-Canogel 2:2 prepared for this invention after 100 cycles. (50 mm min) -1 )

[0058] Figure 21 Stress relaxation curves of i-Canogel 1.5:2.5 prepared for this invention.

[0059] Figure 22 Stress relaxation curves of i-Canogel 2:2 prepared for this invention.

[0060] Figure 23 Stress relaxation curves of i-Canogel 2.5:1.5 prepared for this invention.

[0061] Figure 24 TGA curve of i-Canogel prepared for this invention.

[0062] Figure 25 Infrared curves of i-Canogel 2:2 prepared for this invention during temperature rise.

[0063] Figure 26 Rheological curves of i-Canogel 1.5:2.5 prepared for this invention.

[0064] Figure 27 Rheological curves of i-Canogel 2:2 prepared for this invention.

[0065] Figure 28 Rheological curves of i-Canogel 2.5:1.5 prepared for this invention.

[0066] Figure 29 DSC curve of i-Canogel prepared for this invention.

[0067] Figure 30 DMA curve of i-Canogel 1.5:2.5 prepared for this invention.

[0068] Figure 31 DMA curve of i-Canogel 2:2 prepared for this invention.

[0069] Figure 32 DMA curve of i-Canogel 2.5:1.5 prepared for this invention.

[0070] Figure 33Statistical analysis of the mechanical properties of i-Canogel 1.5:2.5 prepared in this invention.

[0071] Figure 34 Statistical analysis of the mechanical properties of i-Canogel 2.5:1.5 prepared in this invention.

[0072] Figure 35 The stress-strain curves of the original i-Canogel 1.5:2.5 and the repaired sample of this invention are shown after 48 hours at room temperature.

[0073] Figure 36 This is the synthesis path of a1b3a1 in this invention.

[0074] Figure 37 This is the synthesis path of a1b1 in this invention.

[0075] Figure 38 This is the synthesis path of a1b2 in this invention.

[0076] Figure 39 This is the synthesis route for IG-kmn in this invention.

[0077] Figure 40 The 1H NMR spectra of N-hydroxyacetamide, phenylethyl isocyanate, and a1b3a1 are those of the present invention.

[0078] Figure 41 The carbon NMR spectrum of a1b3a1 in this invention.

[0079] Figure 42 The 1H NMR spectra of acetone oxime, phenylethyl isocyanate, and a1b1 are for this invention.

[0080] Figure 43 The NMR carbon spectrum of a1b1 in this invention.

[0081] Figure 44 The 1H NMR spectra of butanone oxime, phenylethyl isocyanate, and a1b2 are those of the present invention.

[0082] Figure 45 The carbon NMR spectrum of a1b2 in this invention.

[0083] Figure 46 The present invention is characterized by (A) the exchange reaction of a1b1 with b2 to produce a1b2 and b1 (top) and a1b3 the exchange reaction of a1 with b2 to produce a1b3 (bottom); and (B) and (C) the evolution of oxime ester bonds without adjacent urea bond catalysis over time at room temperature (0–14°C) with adjacent urea bond catalysis. 1 Evolution of HNMR signals; Oxime ester bonds without adjacent urea bond catalysis (D) and (E) exhibiting characteristics of oxime ester bonds with adjacent urea bond catalysis as they evolve over time at 100 °C. 1Evolution of HNMR signal; (F) Conversion rate of molecular model; (G) Reaction rate of molecular model at 100 °C for 5 minutes.

[0084] Figure 47 The diagram shows the chemical structure of the reaction pathway calculated by internal catalysis in (A) and the calculated Gibbs free energy diagram of the internal catalytic mechanism involving the ortho-urea bond in this invention.

[0085] Figure 48 The present invention includes (A) the chemical structure of IGs; (B) a schematic diagram of the structure of IGs; infrared spectra of ILs, CPUs, and IGs; and (C) 3050–3225 cm⁻¹. -1 (D) 1000–4000cm -1 (E) 1000–1400cm -1 .

[0086] Figure 49 The results are TGA test results for the CPU and IGs of this invention.

[0087] Figure 50 The results are DSC test results for the CPU and IGs of this invention.

[0088] Figure 51 The transparency of IG-4-3-50 in this invention.

[0089] Figure 52 (A) Electrochemical impedance spectroscopy of IGs; (B) Ionic conductivity of IGs.

[0090] Figure 53 The stress-strain curves of the CPU and IGs of this invention are shown.

[0091] Figure 54 The original and self-healing curves of IG-4-3-50 of the present invention are (A) and (B) the self-healing efficiency of tensile strength, elongation at break and toughness of IG-4-3-50.

[0092] Figure 55 (A) Schematic diagram of melt spinning of IG fiber according to the present invention; (B) Actual image of melt spinning of IG fiber.

[0093] Figure 56 The G′ and G″ of (A) IG-2-4-50, (B) IG-4-3-50, (C) IG-6-2-50 and (D) IG-4-3-30 of the present invention are located between 30-180°C.

[0094] Figure 57The stress relaxation curves of (A) IG-4-3-30, (B) IG-4-3-50, and (C) the relaxation times of IG-4-3-30 and IG-4-3-50 fitted to the Arrhenius equation are shown in the figures.

[0095] Figure 58 The present invention includes (A) frequency scan curves of CPU and IGs; and (B) viscosity and shear stress-corresponding shear rate curves of IG-4-3-50.

[0096] Figure 59 This refers to the spinning temperature of the IGs of this invention.

[0097] Figure 60 (A) Photograph of IG-4-3-50 fiber of the present invention. Scale bar: 0.5mm; (B) SEM image of IG-4-3-50 fiber.

[0098] Figure 61 This image shows a SEM image and elemental distribution diagram of the cross-section of the IG-4-3-50 fiber of this invention. Scale bar: 50 μm.

[0099] Figure 62 (A) A winding image of IG-4-3-50 fiber of the present invention; (B) The diameter of IG-4-3-30 fiber at different winding rates.

[0100] Figure 63 The images show (A) the stress-strain curve of IG fiber and (B) a photograph of the tensile test of IG-4-3-30 fiber. Scale bar: 2cm.

[0101] Figure 64 For the present invention, (A) swelling test of IG-4-3-30 fiber; (B) the relationship between the weight retention results of IG-4-3-30 fiber and time under environmental conditions without specific encapsulation.

[0102] Figure 65 The present invention includes (A) the cyclic curve of IG-4-3-30 fiber; (B) the cyclic increment curve of IG-4-3-30; and (C) the hysteresis region corresponding to each loading-unloading cycle.

[0103] Figure 66 The following images represent the stress-strain curves of IG-4-3-30 fibers after 30 seconds of near-infrared photothermal healing according to this invention: (A) original and near-infrared photothermal healing process of IG-4-3-30 fibers; (B) photographs of the near-infrared photothermal healing process of IG-4-3-30 fibers; (C) temperature of IG-4-3-30 fibers irradiated with near-infrared light; and (D) photomicrographs of IG-4-3-30 fibers before and after near-infrared light irradiation. Scale bar: 0.5 cm.

[0104] Figure 67This is a photothermal healing process of IG-4-3-30 fibers in the circuit of this invention and a tensile photograph after healing.

[0105] Figure 68 The present invention provides (A) transparent fibers from recycled IG-4-3-30 fibers to reprocessed fibers; and (B) stress-strain curves of IG-4-3-30 fibers after recycling.

[0106] Figure 69 (A) A stretched and magnified photograph of the fabric woven from IG-4-3-30 fibers according to the present invention. Scale bar: 1 mm; (B) A photograph of an electronic bracelet made of IG-4-3-30 fibers blended with yarn; (C) A stretched photograph of the electronic bracelet; (D) A cyclic stretch curve of the electronic bracelet; (E) A curve showing the change in resistance of the electronic bracelet under different strains (10–50%).

[0107] Figure 70 (A) A schematic diagram of the bulk electroluminescent device of the present invention; (B) A photograph of the bulk electroluminescent device.

[0108] Figure 71 (A) Schematic diagram of IG-4-3-30 and luminescent fiber of the present invention; (B) Schematic diagram of fibrous electroluminescent device; (C) Photograph of IG-4-3-30 fiber moving along luminescent fiber. Scale bar: 1cm; (D) Stable luminescence of IG-4-3-30 fiber when tilted, in contact with, and twisted with luminescent fiber (from left to right). Scale bar: 1cm; (E) Brightness variation of IG-4-3-30 fiber at different contact points with luminescent fiber under different applied voltages.

[0109] Figure 72 This is a schematic diagram illustrating the unity of high strength and room temperature self-healing in materials achieved through endogenous catalysis in this invention.

[0110] Figure 73 This is a schematic diagram illustrating the high strength, rapid processing, and recyclability of the material achieved through endogenous catalysis in this invention. Detailed Implementation

[0111] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0112] Materials involved in the embodiments:

[0113] DMSO-d6 and phenylethyl isocyanate are from The following materials were purchased from beta: Propyl isocyanate from 9dingchem; Acetone oxime and Butyl oxime from Bailingwei; Tetrahydrofuran, Isophorone diisocyanate, and Dibutyltin dilaurate from Sigma-Aldrich; N-hydroxyacetamido and Diaminoacetaldehyde oxime from Bidepharmatech; Fluorinated tetraethylene glycol from fliorochem; Polybutylene glycol adipate (PBGAD, Mw~1000 and 2000) from Jining Baichuan Chemical Co., Ltd. (Jining, China); 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt [EMI][TFSI] (≥99%) from Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences; Dimethylpropanediol (DMBA) from Maclean. Polytetrahydrofuran glycol (PTMEG, Mn = 1000) was supplied by Aladdin and vacuum dried at 110°C for 120 minutes before use. Electroluminescent phosphor (ZnS:Cu) was provided by Shanghai Scientific Phosphorescence Technology Co., Ltd. Triethylamine (TEA, 99%) was purchased from Sinopharm Chemical Reagent Co., Ltd. Sylgard 184 was provided by Tianjin Tianxia Trading Co., Ltd. Unless otherwise specified, all chemicals were used without further purification.

[0114] Unless otherwise specified, all reagents should be used as is without further purification.

[0115] Example 1

[0116] Synthesis of i-Canogel n:m:

[0117] Polybutylene adipate (PBGAD, Mw: 2000) (n mmol) was placed in a glass reactor and dried under vacuum at 110 °C for 2 hours. Then, it was cooled to 70 °C, and IPDI (isophorone diisocyanate) (10 mmol), DBTDL (bisbutyltin dilaurate) (0.2 wt%), FTEG (tetraethylene fluoride) (m mmol), and AMG (j mmol) were dissolved in THF (4 mL). The reaction was carried out under a nitrogen atmosphere while the mixture was magnetically stirred during the reaction. Then, ionic liquids [EMI][TFSI] were added at 0-90 wt% of the total material, and the mixture was stirred for another hour. The reaction mixture was poured into a polytetrafluoroethylene mold and reacted at 60 °C for 24 hours, followed by vacuum curing at 60 °C for another 24 hours to obtain an ionovalently adapted network (i-Canogel n:m).

[0118] The reaction equation is as follows.

[0119]

[0120] Characterization and testing:

[0121] All nuclear magnetic resonance (NMR) spectra were recorded on a Bruker AVANCE 600 NMR spectrometer using deuterated dimethyl sulfoxide (DMSO-d6) as the solvent. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) and heated infrared (TIR) ​​spectra were recorded using a Thermo Scientific Nicolet 8700 spectrometer. The morphology and elemental distribution of the samples were characterized using field emission scanning electron microscopy (FE-SEM, HITACHI SU-8010, Japan) and energy dispersive spectroscopy (Oxford Inca X-Max, UK). Stress relaxation and temperature scanning tests were performed using an Anton Paar MCR702 and a 25 mm solid-state rotor with a sample thickness of 1 mm and a 5% strain applied at 1 Hz. Mechanical properties were investigated using an MTS E42 tensile tester and a 100 N load cell. Unless otherwise specified, the tensile speed for uniaxial and cyclic tensile tests was 50 mm / min. Impedance spectroscopy was performed using a CHI670E electrochemical analyzer. Electrical conductivity was determined using the formula σ = L / AR, where L represents the sample length, A represents the sample cross-sectional area, and R represents the volume impedance. Thermogravimetric analysis (TGA) was performed on a TG 8209F1 thermogravimetric analyzer (NETZSCH, Germany) under a nitrogen atmosphere at a heating rate of 10 °C / min from 40 to 600 °C. Differential scanning calorimetry (DSC) was performed on a DSC-822 differential scanning calorimeter (Mettler Toledo, Switzerland) under a nitrogen atmosphere at a heating rate of 10 °C / min. Furthermore, dynamic mechanical analysis (DMA) was performed on a DMA1 dynamic mechanical analyzer (Mettler Toledo, Switzerland) under an air atmosphere at a heating rate of 5 °C / min and a frequency of 1 Hz. The sample resistance was monitored using a Keithley DMM7510 multimeter.

[0122] Results and discussion:

[0123] Option 1 ( Figure 1 E) represents the endogenous catalytic mechanism of the oxime ester group. A small molecule model of adjacent urea bonds promoting oxime-oxime ester bond exchange was investigated. To synthesize the model molecule, N-hydroxyacetamide reacted with phenethyl isocyanate to obtain the adjacent bond model compound DBD (…). Figure 1 A, Figure 6 A: Option 2). Nuclear magnetic resonance spectroscopy ( 1 H NMR, 13 C NMR was used to confirm the structure of DBD. Figure 6 and 7 Acetone oxime reacts with phenylethyl isocyanate or propyl isocyanate to yield DC or AC.Figure 1 A, Figure 8 A: Option 3 and Figure 10 A: Scheme 4), they lack adjacent urea bonds. The structures of DC and AC are through... 1 HNMR and 13 The 1C NMR was confirmed ( Figures 8-9 At room temperature, use 1 HNMR real-time monitoring of the process by which DBD or DC and A generate ABD or AC and D ( Figure 1 (B and 1C). In 1 In the 1H NMR spectra, the 1.915 or 1.929 ppm signals for DC, 1.918 or 1.933 ppm signals for AC, and 1.737 ppm signals for DBD correspond to the protons of the oxime methyl group. In the control group, the intensity of the 1.915 or 1.929 ppm proton peaks remained constant over time, while the 1.918 or 1.933 ppm proton peaks were almost absent, indicating that almost no AC compound was produced. Figure 1 B). In the [DBD]+[A] experimental group, a significant change in the signal over time was observed. Figure 1 C shows the appearance and gradual enhancement of a proton peak at 1.750 ppm, and a decrease in the peak at 1.737 ppm, indicating the formation of the ABD compound. To quantitatively assess the reaction equilibrium rate, the peak areas of the methyl groups in AC and ABD were integrated. The conversions of AC and ABD can be determined using the equations [AC] / ([DC]+[AC]) and [ABD] / ([ABD]+[DBD]), respectively, where [DC], [AC], [DBD], and [ABD] represent the concentrations of DC, AC, DBD, and ABD at a given time point. After 96 hours at 25 °C, the conversion of AC was almost negligible, while the conversion with the internal catalyst was approximately 35.38%. Figure 1 The results show that the exchange reaction rate was significantly higher in the presence of an internal catalyst than in the absence of one. These results indicate that the exchange reaction rate was faster in the experimental group compared to the control group [DC]+[A], thus demonstrating that adjacent urea bonds play a promoting role in the dynamic exchange reaction of oxime ester groups. This provides clear evidence for the proximity bond participation effect.

[0124] Based on small molecule model studies, an ion-covalently adaptive network with excellent self-healing properties was designed. After observing the enhanced dynamic exchange reaction of oxime ester bonds in the model studies, the next step is to introduce a tetrafunctional AMG topological molecular structure into the polymer network as a crosslinking unit to achieve self-healing. Figure 2A) i-Canogel n:m was synthesized via a one-step polycondensation reaction using commercially available materials: polybutylene adipate diol (PBGAD), fluorinated tetraethanolamine (FTEG), IPDI, AMG, and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([EMI][TFSI]). The reaction was catalyzed by dibutyltin dilaurate. PBGAD was chosen as the soft segment due to its high compatibility with [EMI][TFSI]. FTEG was chosen as the hard and hydrophobic component because it primarily consists of carbon-fluorine (CF) bonds, which are not readily able to provide and accept hydrogen bonds, resulting in strong dipole-dipole interactions between FTEG segments. IPDI was selected as the hard segment due to its unique structure, which not only prevents crystallization but also facilitates the exchange of dynamic structures through its steric hindrance effect. [EMI][TFSI] were selected as functional components not only to enhance chain mobility through physical lubrication but also to impart ionic conductivity to the material, forming an ionic gel. The design and chemical structure of i-Canogel n:m are expressed proportionally as the molar ratio of PGAD and FTEG. Figure 2 B and Figure 12 A schematic diagram is shown in Scheme A, 5. Experiments were conducted using fixed molar ratios of 2.5:1.5 (2.5 mmol, 1.5 mmol), 2:2 (2 mmol, 2 mmol), and 1.5:2.5 (1.5 mmol, 2.5 mmol) PBGAD:FTEG during the synthesis process.

[0125] The structure of i-Canogel was analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Figure 12 B). The observed peak is located at 3375 cm. -1 and 1725cm -1 The values ​​correspond to stretching vibrations of NH and C=O, respectively, indicating the formation of an oxime ester group. It is noteworthy that at 2264 cm⁻¹... -1 No peak corresponding to the N=C=O skeleton stretching vibration was observed, indicating that the IPDI monomer reaction was complete. The fact that i-Canogel 2:2 remained undissolved after immersion in tetrahydrofuran for 24 hours demonstrates the formation of the cross-linked structure. Figure 13 Therefore, the self-healing ability is not caused by residual monomers and non-covalent bonds. Compared with CAN 2:2 without added [EMI][TFSI], the NH peak of i-Canogel 2:2 is lower than that at 3375 cm⁻¹. -1 Towards 3352cm -1 The movement demonstrates that the ionic liquid forms hydrogen bonds with NH in the polymer chain, partially replacing the hydrogen bonds formed by NH and C=O in the network. Figure 14Furthermore, in i-Canogel 2:2, the symmetric stretching vibrations corresponding to the [TFSI] anion and the four vibrational bands of O=S=O, as well as the asymmetric stretching vibrations of CF3 and O=S=O, are located at 1049 cm⁻¹. -1 1132cm -1 1176cm -1 and 1346cm -1 This indicates a high wavenumber shift ( Figure 15 Therefore, the ionic liquid acts as a lubricant, promoting chain mobility and reducing the energy required to form a five-membered ring through the neighboring group participation effect. Furthermore, due to the presence of FTEG segments, [EMI][TFSI] can interact with the polymer chains through ion-dipole interactions. This means that the ionic liquid can be uniformly dispersed in the CAN and will not leak from the network. Elemental mapping of the i-Canogel 2:2 cross-section shows a uniform distribution of C, O, N, F, and S elements, indicating that [EMI][TFSI] is uniformly distributed in the CAN without significant phase separation. Figure 16 The good compatibility between the ionic liquid and the polymer gives i-Canogel excellent transparency.

[0126] The properties of various i-Canogel formulations were evaluated by varying the monomer ratios. PGAD / FTEG molar ratios of 2.5:1.5, 2:2, and 1.5:2.5 were used. Due to the lower molecular weight of FTEG, the hard segment content had the greatest impact on material properties. This explains the wide range of observed properties. To compare the effect of the PGAD / FTEG molar ratio on material properties, the molar ratio of IPDI and AMG was kept constant at 10:3, and the ionic liquid content of each formulation was set to 50 wt%. Uniaxial tensile tests were performed to investigate the mechanical properties of the i-Canogel. Mechanical properties improved with increasing hard segment content in the i-Canogel. In the uniaxial tensile test (… Figure 3 In A), i-Canogel n:m(2.5:1.5,2:2,1.5:2.5) at 50 mm min -1 The fracture strength at tensile rate increased from 3.49±0.3 MPa to 6.48±0.14 MPa, and the toughness also increased from 11.2±1.58 MJ / m. -3 Increased to 20.88±1.8 MJm -3Correspondingly, the Young's modulus of the material also increased significantly from 0.45±0.03 MPa to 0.96±0.44 MPa. Furthermore, due to the hard segments hindering molecular chain movement, the elongation at break decreased from 908.91±35.47% to 714.87±37.14%. The desired properties of i-Canogel are achieved through the combination of non-covalent interactions and reversible four-arm crosslinking units, which respectively lead to high toughness and good elasticity. Cyclic tensile tests were conducted to demonstrate these properties. First, cyclic tensile tests of i-Canogel at different strain ratios showed good tensile resilience (…). Figures 17-19 After 100 cycles of tensile testing at 200% strain, i-Canogel 2:2 still maintained good stability. Figure 20 Secondly, cyclic tensile tests with gradually increasing strain were conducted without a waiting time between two consecutive loading cycles. Figure 3 B) demonstrates the excellent elasticity of i-Canogel 2:2. After stretching i-Canogel 2:2 to 100% strain in the first cycle, the dynamic covalent network and the entropy of unbroken non-covalent interactions (including hydrogen and dipole-dipole interactions) drive the stretched network to almost return to its initial state. This demonstrates that i-Canogel 2:2 is a good elastic conductor in the strain range up to 100%. In subsequent cycles increasing the strain (>100%), the residual strain and hysteresis loop area-strain curves of the resulting stress gradually increase, indicating that a large number of non-covalent bonds break as a sacrifice during continuous stretching, dissipating energy. Furthermore, to demonstrate the elastic properties, repeated cyclic tensile tests at 300% strain were performed on i-Canogel 2:2, with no waiting time between consecutive cycles, for a total of ten cycles. Figure 3 C). The large hysteresis curve in the first cycle indicates significant energy dissipation due to the breaking of non-covalent bonds. Since the non-covalent bonds do not have sufficient time to recover to their original state, the energy dissipation during the second cycle of the cyclic tensile test is significantly lower than in the first cycle. In subsequent tests, the hysteresis decreases slightly with increasing cycle number, indicating continuous sacrificial bond recombination. After relaxation for 2 hours at 25°C, i-Canogel 2:2 shows good elastic recovery in the second cycle test, exhibiting a load-unload curve similar to that of the first cycle.

[0127] To gain a deeper understanding of the dynamic behavior of i-Canogel, stress relaxation tests were performed on all samples at different temperatures to accurately determine the network relaxation time. These tests involved applying a 5% torsional strain and recording the change in relaxation modulus over time. The stress relaxation tests showed that i-Canogel exhibited significant relaxation between 25 and 55 °C, indicating the dynamic dissociation of the oxime ester bonds. Figures 21-23Furthermore, the Maxwell model of viscoelastic fluids was used to determine the relaxation time (τ*), which was found to be 37% of the normalized relaxation modulus (G / G0 = 1 / e = 37%). Additionally, the temperature-dependent behavior of the relaxation time can be expressed by the Arrhenius equation τ(T) = τ0exp(E). a The term is used to describe this using / RT), where τ represents the characteristic relaxation time, τ0 represents the pre-exponential factor, and E a Represents the activation energy for stress relaxation. Ei with i-Canogel 2:2 and i-Canogel 2.5:1.5 a Compared to the value of i-Canogel 1.5:2.5, the E value is... a It was significantly higher, at 77.92 ± 3.99 kJ / mol. -1 The E values ​​of i-Canogel 2:2 and i-Canogel 2.5:1.5 are... a They were 55.56 ± 2.51 kJ mol. -1 and 50.57±1.99kJ mol -1 This indicates that materials with a lower molar ratio of PGAD to FTEG have a stronger network structure and higher thermal stability. Figure 3 These results indicate that the molar ratio of PBGAD to FTEG has a significant impact on the thermal stability and network relaxation of i-Canogel. Thermogravimetric analysis (TGA) was performed to assess the thermal stability of i-Canogel, as the characterization and processing of i-Canogel involve multiple heating steps at high temperatures. Figure 24 The results of TGA showed that all formulations experienced a 5% weight loss (T) under a nitrogen atmosphere. deg At 5%, the temperature is similar, around 260℃. Heating infrared spectroscopy is used to determine the type of oxime ester bond ( Figure 25 At room temperature, the characteristic peak of N=C=O is negligible, but it becomes increasingly prominent with increasing temperature. This indicates that the oxime ester bond dissociates from the N=C=O group, making it a dissociated dynamic bond. When the temperature reaches a certain level, the dissociation of the isocyanate bond far exceeds its recombination, allowing thermosetting materials to exhibit melting points similar to thermoplastic materials. Rheological experiments demonstrate that the melting point of i-Canogel gradually increases with decreasing molar ratio of PGAD to FTEG. Figures 26-28 The melting points of i-Canogel n:m (1.5:2.5, 2:2, 2.5:1.5) are 138.9, 135.9 and 129.5 °C, respectively.

[0128] Furthermore, the room-temperature self-healing properties of i-Canogel were evaluated. The results of stress relaxation experiments showed that the activation energy of the polymer network varies significantly depending on the content of hard and soft segments. This may lead to changes in the dynamic properties of the polymer network and affect its ability to recover from mechanical stress; higher activation energies indicate slower network rearrangement and decreased self-healing ability. Conversely, lower activation energies correspond to easier network rearrangement and improved self-repair capabilities. Theoretically, the lower E1 in i-Canogel 2:2 and i-Canogel 2.5:1.5... a This leads to easier network rearrangement, thereby enhancing the self-healing properties of these i-Canogel formulations. The migration rate of the chain segments in the prepared i-Canogels was evaluated using differential scanning calorimetry (DSC). Figure 29 DSC testing results showed no glass transition point (Tg) in the temperature range of -70 to 200 °C. However, the melting point was consistent with the results obtained from the rheometer. Dynamic mechanical analysis (DMA) was performed to determine the Tg of i-Canogel. Figures 30-32 Data show that the Tg of i-Canogel decreases with increasing PGAD to FTEG molar ratio. The Tg values ​​for i-Canogel n:m (1.5:2.5, 2:2, 2.5:1.5) are -59.6, -63.9, and -67.8 °C, respectively. Tg characterizes the flowability of the polymer chain at room temperature. At room temperature, i-Canogel exhibits excellent elasticity and self-healing properties, thanks to its unique structure involving adjacent bonds. A series of comprehensive tests were conducted to evaluate the self-healing properties of i-Canogel. The self-healing ability of i-Canogel was evaluated using uniaxial tensile tests. Figure 4 A). Before the experiment, an i-Canogel was cut into two pieces and then rejoined under ambient conditions. Self-healing ability was assessed after 24 hours, and the results showed that the tensile strength, elongation, toughness, and Young's modulus of the i-Canogel 1.5:2.5 recovered to 1.58±0.2 MPa, 228.89±52.26%, and 2.52±0.77 MJ / m², respectively. -3 The tensile strength, elongation, toughness, and Young's modulus of i-Canogel 2:2 recovered to 1.09±0.15MPa, 328.89±60.05%, and 2.29±0.67 MJ / m², respectively. -3 and 0.53±0.05MPa ( Figure 4 A and 4C, Figure 33The self-healing efficiencies of i-Canogel 1.5:2.5 and i-Canogel 2:2 were found to be below 50% in all tests, except for Young's modulus, which was found to be greater than 90%. However, i-Canogel 2.5:1.5 exhibited excellent self-healing ability. Its self-healing efficiency was significant, with tensile strength of 98.9%, elongation of 97.4%, toughness of 94.1%, and Young's modulus of 96.6%. Figure 4 A, Figure 34 This indicates that i-Canogel 2.5:1.5 possesses a high ability to recover its mechanical properties after damage. This is likely due to the good compatibility of [EMI][TFSI] with the polymer and the special molecular topological cross-linking structure with neighboring group effect, which gives the material excellent self-healing properties. The mechanical properties of i-Canogel 2:2 exhibit excellent self-healing performance even with a healing time extended to 48 hours. The self-healing efficiencies for tensile strength, elongation, toughness, and Young's modulus are 92.1%, 89.5%, 85.7%, and 98.8%, respectively. Figure 4 B and 4C). The self-healing efficiency of i-Canogel 1.5:2.5 was only slightly higher after 48 hours, which can be attributed to its high content of hard segments (B and 4C). Figure 33 and 35 This conclusion is supported by stress relaxation experimental results and is consistent with activation energy data. The mechanical self-healing properties of ionogels prepared using the neighboring group participation effect have surpassed those of most of the strongest room-temperature self-healing ionogels. Figure 4 D).

[0129] Finally, the electrical properties of i-Canogel were evaluated in detail. [EMI][TFSI] act as a physical lubricant in i-Canogel, improving the mobility and ionic conductivity of the polymer chains. [EMI][TFSI] are very stable and do not evaporate over time because the anions are rich in CF bonds, and their vapor pressure is negligible. Electrochemical impedance spectroscopy showed that the resistance decreased with increasing hard segment content in the system. Figure 5 A) The ionic conductivity of i-Canogel 1.5:2.5, i-Canogel 2:2, and i-Canogel 2.5:1.5 at 25 °C is 4.9 × 10⁻⁶. -2 5.1×10 -2 and 5.7×10 -2 S·m -1 ( Figure 5B). The increased content of hard segments leads to a decrease in segment flexibility, which in turn hinders ion migration within the network. This decrease in ion mobility directly results in a decrease in conductivity. The four-arm crosslinked units and ionic liquids in i-Canogel give it exceptional elasticity, enabling its use as a strain sensor. The ionic conductivity of i-Canogel is affected by temperature. As temperature increases, the ionic conductivity of the material also increases. This can be attributed to the enhanced mobility and easier transport of ions at higher temperatures. Figure 5 C). To evaluate the temperature sensing capability of i-Canogel, i-Canogel 2:2 was selected for evaluation ( Figure 5 D). The temperature sensing performance of i-Canogel 2:2 exhibits a linear variation over the range of 25–60 °C. Furthermore, the sensitivity of i-Canogel 2:2 is determined by the strain coefficient (GF), calculated as GF = (ΔR / R0) / ε, where ΔR is the change in resistance relative to the nominal resistance R0. At zero strain, ε represents the tensile strain applied to the sensor. The resistance of ion-conductive i-Canogel 2:2 is linearly related to the applied strain. Fitting the linear equation to data from practical applications of i-Canogel 2:2 reveals a proportional relationship between the relative change in resistance (ΔR / R0) and the applied small strain, with a strain coefficient of 2.91 over the strain range of 0–75%. For larger strains, the strain coefficient increases to 4.57 over the strain range of 100–300%. Figure 5 E). Due to the non-volatility and hydrophobicity of [EMI][TFSI] and the hydrophobicity of the hard segments in the polymer chain, the weight of i-Canogel remains stable (33-82%) and temperature (-1-30°C) even after 43 days of storage under varying relative humidity conditions. Figure 5 This observation indicates that i-Canogel exhibits environmental insensitivity, making it suitable for use in both open-air and humid environments.

[0130] Example 2

[0131] 1. Preparation of compounds based on oxime ester groups

[0132] 1.1 Preparation of compound a1b3a1

[0133] N-hydroxyacetamide (compound b3, 1 mmol) and phenethyl isocyanate (compound a1, 2 mmol) were dissolved in DMSO-d6 and reacted with stirring at 60 °C under a nitrogen atmosphere for 24 hours. Subsequently, a vacuum treatment was performed at 25 °C for 24 hours. The final product a1b3a1 was obtained. The reaction equation is as follows: Figure 36 As shown.

[0134] 1.2 Preparation of compound a1b1

[0135] Acetone oxime (compound b1, 1 mmol) and phenethyl isocyanate (compound a1, 1 mmol) were dissolved in DMSO-d6 and reacted with stirring at 60 °C under a nitrogen atmosphere for 24 hours. Subsequently, a vacuum treatment was performed at 25 °C for 24 hours. The final product a1b1 was obtained. The reaction equation is as follows: Figure 37 As shown.

[0136] 1.3 Preparation of compound a1b2

[0137] Butanone oxime (compound b2, 1 mmol) and phenethyl isocyanate (compound a1, 1 mmol) were dissolved in DMSO-d6 and reacted with stirring at 60 °C under a nitrogen atmosphere for 24 hours. Subsequently, a vacuum treatment was performed at 25 °C for 24 hours. The final product a1b2 was obtained. The reaction equation is as follows: Figure 38 As shown.

[0138] Preparation of 2IGs

[0139] PGAD (Mw: 1000) underwent vacuum dehydration at 110 °C for 2 hours. PGAD (kmmol) and AMG (m mmol) were first dissolved in 7 mL of THF at 60 °C in a glass container with a magnetic stirrer, where k:m = 6:2, 4:3, and 2:4. Then, IPDI (10 mmol) and DBTDL (0.2 wt%) were added, and the mixture was allowed to react for 15 hours under a nitrogen atmosphere. Next, n wt% (n = 30 or 50) of the total mass of the materials was added of the ionic liquid [EMI][TFSI]. The resulting mixture was then transferred to a PTFE mold and reacted in a 60 °C oven for 24 hours. The solvent was then removed by vacuum for 24 hours, finally yielding the ionic gel IG-kmn. The formulation without the ionic liquid and with k:m = 4:3 was pure polymer CPU. The synthetic route is as follows. Figure 39 As shown.

[0140] In this embodiment, the ratio of PGAD, AMG, and IPDI is maintained at k:m:10.

[0141] Preparation of 3IGs fibers

[0142] IGs fibers were prepared using a 3D printing system. First, the IGs were loaded into an extrusion cylinder equipped with a temperature controller. After heating at 110°C for 15 minutes, they were then extruded using a flat-tipped needle with a diameter of 800 μm at a rate of 20 m / min. -1 The winding speed collects transparent IGs fibers.

[0143] 4. Preparation of waterborne polyurethane (WPU)

[0144] PTMEG was subjected to vacuum dehydration at 110°C for 2 hours. PTMEG, IPDI, and DBTDL were dissolved with THF in a glass container equipped with a magnetic stirrer at 80°C for 2 hours. A mixture of DMBA and THF was then added at 60°C, and stirring continued for 22 hours. TEA was subsequently added, and stirring continued for 30 minutes. The mixture was then cooled to room temperature, water was added to the glass container containing the mixture, and stirring was performed at 2000 rpm for 120 minutes to obtain a clear polyurethane solution. Residual THF was then removed from the mixture by rotary evaporation to obtain a WPU mixture with a solids content of approximately 31.2%.

[0145] 5. Preparation of the light-emitting layer and light-emitting fibers

[0146] To prepare the mixture, ZnS:Cu phosphor and Sylgard 184 were mixed at a weight ratio of 3:1 and stirred on a magnetic stirrer for 30 minutes. The mixture was poured into a film and cured at 100°C for 2 hours to obtain a luminescent layer with a thickness of 300 μm. ZnS:Cu phosphor and WPU were then uniformly mixed at a weight ratio of 3:1 and stirred on a magnetic stirrer for 30 minutes to obtain a homogeneous mixture. Next, IG-4-3-30 fibers were immersed in the mixture at room temperature for 5 minutes. Subsequently, the treated fibers were removed from the mixture and vacuum dried at room temperature. This step was repeated three times to obtain luminescent fibers.

[0147] 6. Testing and Characterization

[0148] 6.1 Nuclear Magnetic Resonance Spectroscopy Test

[0149] Butanone oxime was dissolved in deuterated dimethyl sulfoxide (DMSO-d6) with small molecule model compounds a1b3a1 and a1b1, respectively. 1 1H NMR was used to monitor the reversible reaction process at different temperatures.

[0150] 6.2 Fourier Transform Infrared Spectroscopy (FTIR) Test:

[0151] The sample was tested using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, with 32 scans conducted in the range of 500-4000 cm⁻¹. -1 .

[0152] 6.3 Thermogravimetric Analysis (TGA)

[0153] The thermal stability of the samples was tested using a thermogravimetric analyzer. Test conditions: 1–5 mg sample, N2 atmosphere, heating rate of 10 °C / min. 6.4 Differential Scanning Calorimetry (DSC)

[0154] The sample was tested using a differential scanning calorimeter under an N2 atmosphere, with a gas flow rate of 50 mL / min and a temperature change rate of 10 °C / min.

[0155] 6.5 Morphological structure and elemental distribution characterization

[0156] The cross-sections of IGs were observed using scanning electron microscopy (SEM), and the elemental distribution of the cross-sections was characterized using energy dispersive spectroscopy (EDS).

[0157] 6.6 Transparency Test

[0158] A sample of known thickness was placed in an ultraviolet spectrophotometer to test its transmittance in the range of 400-800 nm.

[0159] 6.7 Mechanical Testing

[0160] Mechanical property testing of IGs includes tensile fracture.

[0161] The IGs were cut into rectangular strips of 20×5×1mm (length×width×height) using a blade. Single tensile tests were conducted using an electronic universal testing machine (100N sensor) at a tensile rate of 50mm / min to obtain their fracture strength, elongation at break, and toughness.

[0162] Mechanical property testing of IGs fibers includes tensile fracture, cyclic tensile strength and cyclic incremental test.

[0163] The IGs fibers were cut into 5mm long short fibers with a blade and subjected to single tensile tests at a tensile rate of 50mm / min using an electronic universal testing machine (100N sensor) to obtain their breaking strength, elongation at break and toughness.

[0164] The fiber was subjected to cyclic tensile tests under strain conditions of 100% and 200%, with a tensile and recovery rate of 50 mm / min and 10 cycles.

[0165] The fiber was subjected to a cyclic incremental strain test, with both the tensile and recovery rates at 50 mm / min, increasing the strain by 100% each time, until the strain reached 800%.

[0166] 6.8 Self-healing performance test

[0167] The rectangular IGs specimen was cut in half lengthwise with a blade, and the cut surface was placed face down. After healing at 70°C for 12 hours, a uniaxial tensile test was performed. The self-healing performance was evaluated by analyzing the mechanical properties (fracture strength, elongation at break, and toughness) of the healed specimen. The self-healing efficiency was defined as the ratio of the tensile strength of the healed specimen to the tensile strength of the original specimen.

[0168] The IG fiber was cut in half with a blade, and the cut surface was exposed. After irradiation with a near-infrared point light source for 30 seconds, a uniaxial tensile test was performed. The self-healing performance was evaluated by analyzing the mechanical properties (breaking strength, elongation at break, and toughness) of the fiber after healing. The self-healing efficiency was defined as the ratio of the tensile strength of the healed fiber to the tensile strength of the original sample.

[0169] 6.9 Impedance Testing and Conductivity Calculation

[0170] Three rectangular IGs samples were placed between two stainless steel electrodes, and their impedance was measured using an electrochemical workstation at a voltage of 10 mV and a frequency of 0.1–100000 Hz. The conductivity (σ) of the ion gel was calculated using the following formula:

[0171] σ=L / (R×A)

[0172] Where L, A, and R represent the thickness, cross-sectional area, and resistance of IGs, respectively.

[0173] 6.10 Strain Sensing Performance

[0174] Different tensile strains were applied to the electronic braided bracelet using a tensile testing machine, and its resistance changes were monitored using a digital multimeter. The sensitivity GF (gauge factor) of the strain sensor was calculated using the following formula:

[0175] GF=(ΔR / R0) / ε

[0176] Where ΔR, R0, and ε are the resistance change, initial resistance, and corresponding deformation of the sensor, respectively.

[0177] 6.11 Rheological Testing

[0178] Stress relaxation tests were performed on IGs samples at different temperatures using a rotational rheometer. A sample with a diameter of 25 mm and a thickness of 1 mm was placed in an aluminum rotor with a diameter of 25 mm. A constant rotor gap was controlled, a frequency of 1 Hz was used, and a strain of 5% was applied.

[0179] Temperature scanning tests were performed on the IGs samples using a rotational rheometer. The sample, with a diameter of 25 mm and a thickness of 1 mm, was placed in an aluminum rotor with a diameter of 25 mm. The rotor was kept at a constant gap, the frequency was 1 Hz, the strain was 0.5%, and the heating rate was 5 °C / min.

[0180] Frequency scanning tests were performed on IGs samples at different temperatures using a rotational rheometer. A sample with a diameter of 25 mm and a thickness of 1 mm was placed in an aluminum rotor with a diameter of 25 mm. By controlling the rotor gap to be constant, the frequency range was 0.1-100 Hz, and a strain of 5% was applied.

[0181] 6.12 Luminous intensity test

[0182] The electroluminescence function of the samples was evaluated using a Konica Minolta CS-200 screen luminance meter. Unless otherwise specified, the experimental conditions for the electroluminescent region located between the luminescent fiber or the PDMS@ZnS:Cu electroluminescent layer and the IG-4-3-3-30 fiber were 4V / μm. -1 and 5kHz.

[0183] 7.1 Structural characterization of compounds based on oxime ester groups

[0184] The structures of the small molecule product a1b3a1 and its synthetic monomer starting materials were confirmed using nuclear magnetic resonance (NMR). The hydrogen protons and carbon atoms of all monomers were assigned in the proton and carbon spectra, respectively. Figure 40 and 41 N-hydroxyacetamide: 1 ¹H NMR (600MHz, DMSO-d6) δ 1.62 (s, 3H). Phenylethyl isocyanate: 1 HNMR (600MHz, DMSO-d6) δ7.33 (t, J = 7.4 Hz, 2H), 7.29–7.23 (m, 3H), 3.58 (t, J = 6.7 Hz, 2H), 2.87 (t, J = 6.7 Hz, 2H). a1b3a1: 1 HNMR (600MHz, DMSO-d6) δ7.33–7.27 (m, 4H), 7.21 (t, J = 7.4Hz, 6H), 3.34–3.27 (m, 2H), 3.23(q,J=7.0Hz, 2H), 2.81–2.74(m, 2H), 2.67(t,J=7.3Hz, 2H), 1.74(s, 3H).

[0185] The structures of the small molecule product a1b1 and its synthetic monomer starting materials were confirmed using nuclear magnetic resonance (NMR). The hydrogen protons and carbon atoms of all monomers were assigned in the proton and carbon spectra, respectively. Figure 42 and 43 Acetone oxime: 1 ¹H NMR (600 MHz, DMSO-d⁶) δ 1.76 (s, 3H), 1.73 (s, 3H). Phenylethyl isocyanate: 1 H NMR (600MHz, DMSO-d6) δ7.33 (t, J=7.4Hz, 2H), 7.29–7.23 (m, 3H), 3.58 (t, J=6.7Hz, 2H), 2.87 (t, J=6.7Hz, 2H). a1b1: 1H NMR (600MHz, DMSO-d6) δ7.29 (t, J = 7.5Hz, 2H), 7.20 (d, J = 7.4Hz, 3H), 3.33–3.26 (m, 2H), 2.78–2.74 (m, 2H), 1.92 (s, 3H), 1.91 (s, 3H).

[0186] The structures of the small molecule product a1b2 and its synthetic monomer starting materials were confirmed using nuclear magnetic resonance (NMR). The hydrogen protons and carbon atoms of all monomers were assigned in the proton and carbon spectra, respectively. Figure 44 and 45 Butanone oxime: 1 ¹H NMR (600 MHz, DMSO-d⁶) δ 2.22 (q, J = 7.7 Hz, 1H), 2.11 (t, J = 7.5 Hz, 1H), 1.72 (d, J = 19.3 Hz, 3H), 1.02–0.93 (m, 3H). Phenylethyl isocyanate: 1 H NMR (600MHz, DMSO-d6) δ7.33 (t, J=7.4Hz, 2H), 7.29–7.23 (m, 3H), 3.58 (t, J=6.7Hz, 2H), 2.87 (t, J=6.7Hz, 2H). a1b2: 1 ¹H NMR (600 MHz, DMSO-d⁶) δ 7.29 (d, J = 7.1 Hz, 2H), 7.22–7.19 (m, 3H), 3.31 (q, J = 7.4, 7.0 Hz, 2H), 2.77 (t, J = 7.5 Hz, 2H), 2.34 (q, J = 7.7 Hz, 1H), 2.30–2.23 (m, 1H), 1.90 (d, J = 12.7 Hz, 3H), 1.03 (dt, J = 17.8, 7.6 Hz, 3H). 7.2 Internal catalytic model near urea bonds.

[0187] Although extensive research has been conducted on the role of neighboring bonds as intrinsic catalysts in promoting covalent bond exchange, their significant potential—namely, lowering reaction energy barriers, enhancing dynamic bond exchange rates, and potentially enabling the conversion of high-temperature dynamic bonds to room-temperature dynamic bonds—remains largely unexplored. We investigated the exchange kinetics of oxime ester bonds using model compounds with and without neighboring urea bonds. The reaction of N-hydroxyacetamide with phenethyl isocyanate yielded the neighboring bond model compound a1b3a1. 1 H and 13 The structure of a1b3a1 was confirmed by C1NMR analysis. A1b1 and a1b2 were obtained by reacting acetone oxime and diacetyl dioxime with phenethyl isocyanate, respectively; both compounds lack adjacent urea bonds. 1 H and 13C1NMR confirmed the structures of a1b1 and a1b2. The validation model of neighboring group catalysis included two types: (1) the experimental group involved the reaction between a1b3a1 and b2; and (2) the control group involved the reaction between a1b1 and b2. Figure 46 A). At room temperature (0–14℃), use 1 H NMR was used to monitor the real-time evolution of compounds a1b1 and b2 into a1b2 and b1. Figure 46 B). b2 and a1b2 1 The HNMR signals at 1.718 ppm and 1.898 ppm correspond to protons in diacetyl oxime methyl. However, the control group spectrum did not show a proton peak at 1.898 ppm, indicating that compound a1b2 was not produced. At room temperature (0–14 °C), the [a1b3a1]+[b2] concentration in the experimental group changed significantly over time. Figure 46 C shows the appearance and gradual enhancement of a proton peak at 1.898 ppm, indicating the formation of compound a1b2. Furthermore, to verify whether NPG can accelerate the exchange rate of dynamic bonds at high temperatures, we repeated the above experiment at 100 °C. Figure 46 D and E show the appearance and gradual enhancement of the peak at 1.898 ppm, while the peak intensity at 1.718 ppm decreases, indicating the formation of compound a1b2. To quantitatively assess the reaction equilibrium rate, the methyl group in a1b2 was integrated. The conversion of a1b2 was calculated using the equation [a1b2] / ([b2]+[a1b2]), where [b2] and [a1b2] represent the concentrations of b2 and a1b2 at a specific time point, respectively. After a reaction of 330 minutes, the conversion of a1b2 in the experimental group was consistently higher than that in the control group, and its exchange rate was also higher than that of the control group shortly after heating. Figure 46 F). Furthermore, the effect of internal catalysis on the rate of the oxime ester exchange reaction was quantified. It is known that the oxime ester exchange reaction is essentially a transcarbamylation reaction, which is a first-order reaction. The calculation of the chemical reaction rate is applicable to the first-order rate equation k. -1 =-ln([b2]) T / [b2]0) / T, where T represents the reaction time, [b2] T [b2]0 represents the concentration of compound b2 at reaction time T, and [b2]0 represents the initial concentration of compound b2. Using this equation, it was determined that when the reaction was carried out at 100°C for 5 minutes, the reaction rate of the experimental group was 3.8 times that of the control group. Figure 46 Furthermore, experimental results obtained at high temperatures (100°C) and low temperatures (0–14°C) indicate that adjacent urea bonds not only enhance the exchange rate of oxime-urea esters at high temperatures, but also convert oxime ester bonds at high temperatures into dynamic bonds at room temperature, thus providing clear evidence for the NPG effect.

[0188] 7.3 Density Functional Theory (DFT) Calculation Study of the Endogenous Catalytic Mechanism of Neighboring Urea Bonds

[0189] Notably, compared to previously reported dynamic covalent polyurethane-polyurea networks, polyurethane-polyurea networks containing endogenous catalysts exhibit significantly different characteristics: adjacent urea bonds can act as catalysts to significantly promote transaminoformylation. Inspired by this unique property, we used the reaction products of phenethyl isocyanate and N-hydroxyacetamide as model substrates for DFT calculations. We employed geometric optimization and frequency calculations at the M06-2X / 6-31+G(d,p) theoretical level, and single-point calculations at the M06-2X / def2-TZVP theoretical level, to investigate the exchange reaction mechanism catalyzed by adjacent urea bonds. First, we obtained all possible adjacent urea bond catalytic shearing pathways ( Figure 47 A). For example Figure 47 As shown in B, the nitrogen atom in the urea bond nucleophilically attacks the carbonyl carbon in the oxime amide bond, forming a five-membered ring transition state; this reaction involves an intramolecular proton transfer from the nitrogen atom of the urea bond to the carbonyl group of the urea bond, generating -C=OH. + This forms the intermediate dipole int2b via the transition state TS1b. During the formation of the normal molecule int2a via the transition state TS1a, the proton of the urea bond N is transferred to the carbonyl group of the oxime ester bond, forming -C-OH. The activation energy of int2b is 30.6 kcal / mol higher than that of int2a. -1 This increases the likelihood of Step 1a. After the formation of intermediate int2a, the electron cloud distribution of the CO bond in the oxime amide bond becomes uneven due to the electron attraction of C=N in the oxime-urea bond, increasing the possibility of bond breaking. We designed two possible steps for this process: Step 2a and Step 2b. Step 2a generates int3a via intramolecular proton transfer through the transition state TS2a. Step 2b generates the charged dipole intermediate int3b via the transition state TS2b, where the CO bond breaks to form the O- anion without intramolecular proton transfer. However, our calculations show that int3b either does not exist or is extremely unstable, as the structural optimization of int3b spontaneously converges to int2a. Furthermore, Step 2a requires a smaller energy barrier, while int3a is structurally stable. Finally, we designed three steps to dissociate isocyanate. The activation energy barriers for the conversion of int3a to TS3 in Step 3a and the conversion of int3c to int3d in Step 3c are 21.9 kcal / mol. -1 and 55.5 kcal mol -1 In Step 3b, the conversion from int3a to int3d requires only 14.6 kcal / mol.-1 Ultimately, isocyanate completes the cleavage of the oxime amide bond via intramolecular proton transfer coordination through the transition state TS4. The final pathway of the transcarbamylation reaction catalyzed by adjacent urea bonds is determined to be RC—int1—TS1a—int2a—TS2a—int3a—int3d—TS4—int6+int5—int4+int5, where the key step involves the nucleophilic attack of the nitrogen atom of the urea bond on the carbonyl carbon atom to form a five-membered ring, followed by intramolecular proton transfer.

[0190] 7.4 Synthesis and Performance Characterization of IGs

[0191] Given the significant dynamic exchange reactions observed in the oxime ester bonds during model studies, the reversible topological molecular structure of AMG was introduced into CANs as a crosslinking unit. Figure 48 A). The synthesis of IGs was achieved through a one-step condensation reaction using commonly used materials, including poly(butanediol-adipic acid) glycol (PBGAD), isophorone diisocyanate (IPDI), diaminoacetaldehyde oxime (AMG), and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([EMI][TFSI])(ILs). PGAD was chosen as the soft segment due to its excellent compatibility with [EMI][TFSI]. IPDI was chosen as the hard segment due to its unique structure, which not only hinders crystallization but also promotes the exchange of dynamic structures through steric hindrance. [EMI][TFSI] was chosen as the functional component primarily because it enhances chain fluidity through physical lubrication and imparts ionic conductivity to the material, ultimately forming an ionic gel. The design and chemical structure of the IG-kmn are represented by the molar ratio (km) of PGAD to AMG and the mass ratio (n) of the ILs in the gel. The resulting four-arm crosslinked network structure is shown below. Figure 48 As shown in Figure B, the molecular interactions between [EMI][TFSI] and the polymer were investigated using attenuated total reflectance Fourier transform infrared spectroscopy. Compared to the peaks of pure [EMI][TFSI], the CH stretching vibration peaks of [EMI]imidazolium in IG shifted downwards to 3159.5 and 3123.8 cm⁻¹. -1 ( Figure 48 C), and due to the addition of IL, the stretching vibration peaks of NH, CH, and C=O shifted upwards to 3366.9, 2952.1, and 1727.6 cm⁻¹, respectively. -1 ,like Figure 48 As shown in Figure D, this confirms the formation of hydrogen bonds between [EMI][TFSI] and the polymer chain. Furthermore, the 2264 cm⁻¹ vibration corresponding to the N=C=O skeletal stretching vibration was not observed. -1The characteristic peaks indicate that the IPDI monomer has completely reacted. Furthermore, four vibrational bands corresponding to the symmetrical SNS and O=S=O stretching vibrations of the [TFSI] anion and the asymmetric CF3 and O=S=O stretching vibrations are observed at 1051.6, 1133.4, 1179.7, and 1347.1 cm⁻¹, respectively. -1 At this point, a downward shift appeared in the IG spectrum ( Figure 48 E). This indicates that ionic liquids, acting as lubricants, promote chain fluidity.

[0192] Considering the multiple heating steps involved in characterizing and processing IGs, thermogravimetric analysis (TGA) was performed to assess the thermal stability of IGs. Figure 49 The thermal decomposition temperature of pure polymeric CPUs without ionic liquids is 269℃. The introduction of ILs increases the thermal decomposition temperature of IGs, thus making them more stable.

[0193] Differential scanning calorimetry (DSC) confirmed the plasticizing effect of ILs. Due to the addition of ILs, the glass transition temperatures of IGs were all lower than those of CPUs. Keeping the hard-soft segment ratio of the CPU constant (k:m = 4:3), when the IL content was 30 wt%, the glass transition temperature of the CPU decreased from -43.7℃ to -61.3℃. Figure 50 It is worth noting that when the ILs content increases to 50 wt%, the glass transition temperature is below -65 °C.

[0194] Due to the high compatibility between the polymer and the IL, IGs exhibit high transparency. For example, a 1 mm thick IG-4-3-50 film has an average transmittance of over 91% in the visible light wavelength range of 400–800 nm. Figure 51 ).

[0195] Furthermore, the introduction of IL imparts ionic conductivity to CPUs. The ionic conductivity of IG-6-2-50, IG-4-3-50, IG-2-4-50, and IG-4-3-30 at 25 °C is 2.73 × 10⁻⁶. -2 1.95×10 -2 1.78×10 -2 and 0.25×10 -2 S m -1 ( Figure 52 ).

[0196] The mechanical properties of CPUs and IGs were investigated using uniaxial tensile testing. The mechanical properties of IGs increased with increasing AMG content. The tensile rate was 50 mm / min. -1Under the specified conditions, the fracture strengths of IGs with an ionic liquid content of 50 wt% were 2.40 ± 0.16 MPa, 8.67 ± 0.36 MPa, and 19.06 ± 1.63 MPa, respectively, while the elongations at break were 879.87 ± 12.57%, 959.47 ± 72.99%, and 642.30 ± 57.95%, respectively. Figure 53 With a PGAD:AMG (km) molar ratio of 4:3, as the ILs content in IGs increased from 0 wt% to 30 wt% and 50 wt%, the mechanical strength of the material gradually decreased due to the plasticizing effect of ILs. The fracture stress and elongation at break of CPU, IG 4-3-30, and IG 4-3-50 were 30.90±6.82 MPa, 784.90±123.32%; 14.06±0.89 MPa, 1010.03±87.72%; and 8.67±0.36 MPa, 959.47±72.99%, respectively.

[0197] Considering the four-armed dynamic unit with endogenous catalysis as the crosslinking point of CANs, a self-healing test was performed on IG-4-3-50. After cutting the IG-4-3-50 sample with a blade and placing it in an oven at 70°C for 12 hours, its mechanical properties were almost completely restored. Figure 54 A). The self-healing efficiencies of IG-4-3-50 in terms of tensile strength, elongation at break, and toughness were 98.1%, 98%, and 91.2%, respectively. Figure 54 B).

[0198] Spinnability Study of 7.5IGs

[0199] At the crosslinking points, the oxime ester bonds catalyzed by adjacent urea bonds exhibit high dynamics at high temperatures, thereby enhancing the material's topological recombination ability at high temperatures. This enables rapid spinning of IGs. Figure 55 A and B show schematic diagrams of IG spinning and actual images of the spinning process.

[0200] The processing performance of IGs was verified by rheological testing. Temperature scanning experiments showed that both the storage modulus (G') and loss modulus (G”) of IGs decreased with increasing temperature, indicating that the cross-linked structure of IGs gradually dissociated at high temperatures. Furthermore, with increasing AMG content, the melting point of IG gradually increased to 110.48℃, 126.71℃, and 152.01℃. Figure 56 AD). For example Figure 56 As shown in B and D, the IL content of 30 wt% and 50 wt% has little effect on the melting point of IGs.

[0201] To gain a deeper understanding of the dynamic behavior of IG-4-3-n, stress relaxation tests were conducted on samples at different temperatures to accurately determine the network relaxation time. A 5% torsional strain was applied to the IGs, and the relaxation modulus as a function of time was recorded. The plasticity of IG at high temperatures was investigated through variable-temperature stress relaxation analysis. Figure 57 (A and B). All samples exhibited complete stress relaxation, indicating significant ductility of IG at high temperatures. Furthermore, IG-4-3-n showed significant relaxation between 75-90 °C, indicating dynamic dissociation of the oxime ester bond. The relaxation time (τ*) was determined using a Maxwell model of viscoelastic fluids, and was found to be 37% of the normalized relaxation modulus (G / G0 = 1 / e = 37%). Moreover, the temperature-dependent behavior of the relaxation time can be expressed by the Arrhenius equation τ(T) = τ0exp(E). a The term is used to describe this using / RT), where τ represents the characteristic relaxation time, τ0 represents the pre-exponential factor, and E a This represents the activation energy for stress relaxation. The stress relaxation energy E for IG-4-3-30 and IG-4-3-50. a The values ​​were 110.66±12.71 and 103.30±1.66 kJ / mol, respectively. – 1 ( Figure 57 C) indicates that when the ratio of soft to hard segments is known, the IL content has minimal impact on the dynamic behavior of the material network.

[0202] In the swept-frequency rheological test, the storage modulus of the material consistently exceeded the loss modulus, indicating excellent elasticity at room temperature. Figure 58 A). With increasing AMG proportion, the modulus increases, indicating an increase in the degree of crosslinking and hydrogen bond density of the material. Furthermore, significant shear thinning was observed in the frequency sweep test of IG-4-3-50 at 120°C, indicating improved spinnability of the material. Figure 58 B).

[0203] Based on the previous tests, we conducted melt spinning tests on CPU and IG at different temperatures to determine the spinning temperature for each formulation. Figure 59 The display indicates that IG-2-4-50 cannot be spun between 110°C and 140°C. The spinning temperature range for IG-4-3-50 and IG-4-3-30 is 110-125°C, while the spinning temperature range for IG-6-2-50 is 110-120°C.

[0204] We spun IG-4-3-30 at different spinning rates, collected the fibers, and photographed them. The results revealed the changes in fiber diameter at different spinning rates. Figure 60A). The obtained IG-4-3-30 fibers exhibit a smooth, cylindrical shape with high transparency. Scanning electron microscopy (SEM) images show that the cross-section of the fibers is smooth and circular. Figure 60 B).

[0205] The cross-sectional elemental distribution diagram of IG-4-3-30 fibers shows a uniform distribution of C, O, N, F, and S. This uniform distribution indicates that [EMI][TFSI] are uniformly dispersed in the fibers, and there is no obvious phase separation. Figure 61 ).

[0206] The significant compatibility of [EMI][TFSI] with polymers contributes to the high transparency of IG-4-3-30 fibers. Due to their excellent spinnability and formability, IG-4-3-30 fibers can be continuously produced and are easy to collect. Figure 62 A). As the winding rate increases from 2 to 20 m / min -1 The fiber diameter decreased from 8.76±1.54 mm to 3.45±0.43 mm. Figure 62 B).

[0207] 7.6IGs fibers' self-healing and remodeling properties

[0208] Based on previous spinnability studies, we manufactured fibers using three different formulations: IG-4-3-30, IG-4-3-50, and IG-6-2-50. Uniaxial tensile testing was performed to evaluate the mechanical properties of the IG fibers. Figure 63 A). The mechanical strength of all IGs significantly increased after melt spinning into IG fibers, which can be attributed to the shear forces during extrusion causing the polymer network to orient along the spinning direction. Furthermore, the stretching induced by rapid spinning further enhanced the orientation. These orientation effects endow the fibers with superior properties compared to the original material. Among the three formulations, IG-4-3-30 fibers exhibited the highest mechanical strength, reaching 23.20 MPa. Even during large-scale stretching, the fibers maintained excellent transparency (…). Figure 63 B).

[0209] Due to its chemically cross-linked structure, IG-4-3-30 fibers exhibit significant solvent resistance. Figure 64 A). IG-4-3-30 exhibits excellent stability under environmental conditions (relative humidity = 55%, temperature = 15℃), and due to the large number of CF bonds in [EMI][TFSI], IG-4-3-30 fibers possess good hydrophobicity. Figure 64 B).

[0210] Furthermore, the cyclic tensile curves indicate that IG-4-3-30 fibers possess excellent elasticity. Figure 65A). The reinforcing and toughening properties of IG-4-3-30 fiber were elucidated through cyclic tensile tests, in which strain increase was not delayed ( Figure 65 B). The hysteresis region of each load-unload cycle is plotted relative to the strain on... Figure 65 In C, the hysteresis region is minimal when the strain is below 100%, indicating primarily elastic deformation with negligible hydrogen bond breakage. Above 100% strain, the rapid increase in the hysteresis region indicates effective energy dissipation, enhancing the toughness of the IG-4-3-30 fiber.

[0211] Furthermore, the four-armed dynamic units with endogenous catalysis serve as crosslinking points, enabling IG-4-3-30 fibers to undergo rapid and precise healing under near-infrared light. Under near-infrared light, the healing process takes only 30 seconds, and the material strength recovers to 83.3% of its original value. Figure 66 A). Next, we observed the rapid near-infrared repair rate of IG-4-3-30 fibers from both macroscopic and microscopic perspectives. First, after being cut and aligned, the IG-4-3-30 fibers were stretched to four times their original length within seconds of near-infrared light irradiation. Figure 66 B). Infrared thermal imaging showed that after a few seconds of exposure, the temperature of the irradiated area reached 92.7°C, providing sufficient energy for NGs to promote the exchange of dynamic bonds. Figure 66 C). Secondly, the healing process of the incision site was observed using a microscope. Figure 66 D indicates that as near-infrared light irradiation led to an increase in temperature, the internal polymer network of the fibers migrated, thereby enabling rapid incision alignment. The incision became less noticeable after 6 seconds of exposure and completely healed after 9 seconds.

[0212] Compared to the corresponding IG-4-3-30 thin film, IG-4-3-30 fibers also exhibit excellent ionic conductivity. When used as an ionic conductor in a closed circuit, IG-4-3-30 fibers successfully maintain the brightness of a light-emitting diode (LED). Figure 67 However, when the IG-4-3-30 fiber is stretched, the brightness of the emitted light gradually decreases due to the increase in resistance. This indicates that IG-4-3-30 fiber has potential applications in strain sensors.

[0213] In addition to being repairable, IG-4-3-30 fibers can also be reprocessed and recycled. To test the reprocessability of IG-4-3-30 fibers, the fibers were collected and respun through melt extrusion. Figure 68 A). The mechanical properties of the recycled IG-4-3-30 fibers are almost identical to those before recycling, indicating their excellent recyclability. Figure 68 B).

[0214] 4.3.7 Application of IG Fibers in Flexible Electronics

[0215] IG-4-3-30 fiber possesses electrical conductivity, flexibility, high tensile strength, and transparency, exhibiting mechanical properties consistent with human soft tissue and adapting to deformation during various movements, thus meeting the needs of wearable electronics. Furthermore, the developed fiber offers a variety of processing methods, allowing for the manufacture of diverse devices using different processing techniques. Figure 69 A shows a stretchable IG fabric with a clearly woven structure as observed under a microscope. By utilizing its weaving properties, IG-4-3-30 fibers are blended with yarn to create an electronic bracelet (E-bracelet). Figure 69 B). Although the yarn lacks stretch and conductivity, IG-4-3-30 fiber compensates for these deficiencies, giving the electronic bracelet excellent tensile elasticity. Figure 69 C). The cyclic stretching curves demonstrate the commendable elasticity of the electronic wristband, with minimal hysteresis observed at 10–50% strain, indicating minimal energy loss during stretching. Figure 69 D). Strain sensors typically require conductors with excellent elastic and resistive response; electronic wristbands have been found to meet these requirements. Figure 69 E illustrates the change in resistance of the electronic wristband during cyclic tensile testing at different strains (10-50%). The highly repeatable resistance change of the electronic wristband sensor during repeated tensile-release cycles demonstrates its highly sensitive and reliable sensor performance over a wide strain range of 10% to 50%.

[0216] Beyond sensors, flexible displays are crucial for advancing flexible electronics, as smart electronic textiles with integrated displays are revolutionizing human-computer interaction—a highly sought-after feature in wearable technology. We directly printed fibers bearing the letters "DHU" and combined them with a PDMS@ZnS:Cu electroluminescent layer and an IG thin film to fabricate a flexible, bulk electroluminescent device. Figure 70 A). This structure resembles a sandwich, with a dielectric luminescent layer situated between two IG layers. When an alternating voltage is applied to the IG film and the "DHU" IG fiber, the two IG layers generate opposite polarities, causing the intermediate luminescent layer at the contact area between the "DHU" IG fiber and the PDMS@ZnS:Cu film to emit light, thus displaying the luminescent letters "DHU". Figure 70 B). The highly transparent IG-4-3-30 fiber allows light of various colors from the luminescent layer to pass through.

[0217] To highlight the advantages of the fiber, we manufactured a core-shell structured luminescent fiber by post-processing IG-4-3-30 fiber by immersing it in a waterborne polyurethane (WPU) mixed with ZnS:Cu. Figure 71A). When the IG-4-3-30 fiber comes into contact with the light-emitting fiber, a sandwich structure similar to that of a bulk light-emitting device is formed in the contact area. This structure consists of the IG-4-3-30 fiber, the shell layer WPU@ZnS:Cu of the light-emitting fiber, and the core layer of the IG-4-3-30 fiber. When an alternating voltage is applied to the IG-4-3-30 fiber and the light-emitting fiber, light emission is triggered at the contact point, following the same principle as a bulk light-emitting device. Figure 71 B). Figure 71 As shown in Figure C, the brightness remained relatively constant when the IG-4-3-30 fibers contacted the luminescent fibers at different locations, indicating that the luminescent fiber shell was uniformly prepared. Due to the diverse contact patterns between fibers during the weaving process, stable luminescence was observed when the IG-4-3-30 fibers were tilted, in contact with, and twisted towards the luminescent fibers. Figure 71 D). Finally, the electroluminescence properties of the fiber were quantitatively characterized. Figure 71 E). As the applied voltage increases from 0.7V / μm -1 Increased to 4Vμm -1 The brightness of the luminescent layer increased from 0.2±0.1 to 209.1±16.7 cd / m². -2 Overall, the electronic wristbands and flexible bulk electroluminescent devices based on IG-4-3-30 fibers demonstrated excellent performance and the potential for large-scale continuous manufacturing of flexible smart textiles.

[0218] In summary, this invention is the first to introduce endogenous catalysis into crosslinking units to construct polymers. The presence of neighboring groups significantly enhances the reversibility of dynamic bonds, thereby greatly improving the dynamic behavior of the network. Combined with a topological design of multiple crosslinking points at a single site, the resulting i-Canogel exhibits excellent mechanical strength and self-healing properties at room temperature. Figure 72 The resulting IGs achieve a balance between high mechanical strength and machinability. Figure 73 The introduction of adjacent urea bonds provides a novel approach to modulating dynamic oxime ester groups. Given the wide application of polyurethanes, this crosslinking agent holds significant importance. The four-armed crosslinking unit, combining electronic effects, steric effects, and topological characteristics in a synergistic manner, offers a new chemical pathway for controlling material properties.

Claims

1. A polyurethane, characterized in that, The polyurethane structural formula is: ； Wherein R1 is the remaining group after removing the diisocyanate group from a diisocyanate containing a benzene ring or an asymmetric alicyclic structure; R2 is the remaining chain segment after removing the hydroxyl group from a macromolecular diol; and R3 is the remaining molecular chain after removing the hydroxyl group from a small molecule diol. The values ​​are x = 100-1000; y = 100-1000; z = 100-1000.

2. The polyurethane according to claim 1, characterized in that, The diisocyanate includes isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, or toluene diisocyanate; the macromolecular diol includes polyethylene adipate diol, polybutylene adipate diol, polyhexylene adipate diol, polycarbonate diol, polytetrahydrofuran diol, polycaprolactone diol, polypropylene glycol, or perfluoropolyether diol; the small molecule diol includes 1,4-butanediol, ethylene glycol, propylene glycol, fluorinated tetraethanol, fluorinated ethylene glycol, fluorinated propylene glycol, or fluorinated butylene glycol.

3. A dynamic covalently adaptive polyurethane network composite material, characterized in that, The composite material components include the polyurethane and ionic liquid described in any one of claims 1-2.

4. The dynamic covalently adaptive polyurethane network composite material according to claim 3, characterized in that, The ionic liquid in the dynamically covalently adapted polyurethane network composite material accounts for 10-90 wt%; The ionic liquid comprises one or more of the following: 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylpyridine hexafluorophosphate, and 1-ethyl-3-methylimidazolium dicyandiamide salt.

5. A method for preparing the dynamic covalently adaptive polyurethane network composite material according to claim 3, comprising: A diisocyanate containing a benzene ring or asymmetric alicyclic structure, a four-arm crosslinking agent, a macromolecular diol and / or a small molecule diol, a catalyst, an ionic liquid, and a solvent are mixed and subjected to a nucleophilic addition reaction to obtain a prepolymer. Then, a crosslinking reaction is carried out to obtain a dynamically covalently adapted polyurethane network composite material. Alternatively, a diisocyanate containing a benzene ring or asymmetric alicyclic structure, a four-arm crosslinking agent, a macromolecular diol and / or a small molecule diol, a catalyst, and a solvent can be mixed and subjected to a nucleophilic addition reaction to obtain a prepolymer. Then, an ionic liquid is added, and a crosslinking reaction is carried out to obtain a dynamically covalently adapted polyurethane network composite material.

6. The preparation method according to claim 5, characterized in that, The diisocyanate includes one or more of isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and toluene diisocyanate; The four-arm crosslinking agent is diaminoglyoxime; The ionic liquid comprises one or more of the following: 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide, 1-hexyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide salt, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-hexyl-3-methylpyridine hexafluorophosphate, and 1-ethyl-3-methylimidazolium dicyanamide salt. The catalyst includes one or more of dibutyltin dilaurate, stannous octoate, and triethylamine; the solvent includes one or more of THF, Acetone, DMAC, DMSO, and DMF. The macromolecular diol has a molecular weight of 600-5000; the small molecule diol has a molecular weight of 100-500.

7. The preparation method according to claim 6, characterized in that, The macromolecular diols include polyethylene adipate diol, polybutylene adipate diol, polyhexane adipate diol, polycarbonate diol, polytetrahydrofuran diol, polycaprolactone diol, polypropylene glycol, or perfluoropolyether diols; the small molecule diols include 1,4-butanediol, ethylene glycol, propylene glycol, tetrafluorinated ethanol, fluorinated ethylene glycol, fluorinated propylene glycol, or fluorinated butylene glycol.

8. The preparation method according to claim 5, characterized in that, The molar ratio of the diisocyanate containing a benzene ring or asymmetric alicyclic structure to the diol is 10:4 to 10:6; the molar ratio of the diisocyanate containing a benzene ring or asymmetric alicyclic structure to the four-arm crosslinking agent is 10:1 to 10:4; the ratio of the diisocyanate containing a benzene ring or asymmetric alicyclic structure to the solvent is (15-40) mmol: (3-10) mL; the molar ratio of the macromolecular diol to the four-arm crosslinking agent is (1-8): (1-5); and the molar ratio of the macromolecular diol to the small molecule diol is 1:3 to 5:

1.

9. The preparation method according to claim 5, characterized in that, The nucleophilic addition reaction is carried out at a temperature of 60-100℃ for 15-24 hours; the crosslinking reaction is carried out at a temperature of 60-100℃ for 24-48 hours.

10. A material, characterized in that, The material is fiber, membrane, or woven fabric; wherein the fiber comprises the fiber of the dynamically covalently adapted polyurethane network composite material of claim 3; the membrane comprises the membrane of the dynamically covalently adapted polyurethane network composite material of claim 3; and the woven fabric comprises a woven fabric of the fibers of the dynamically covalently adapted polyurethane network composite material.

11. The application of the dynamic covalently adaptive polyurethane network composite material of claim 3 in the field of flexible electronics.

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