High-strength and high-toughness polyelectrolyte glass, and preparation method and application thereof

Abstract

The application relates to the technical field of high-molecular conductive materials, in particular to a high-strength and high-toughness polyelectrolyte glass as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing polyelectrolyte elastomer monomers, rigid high-molecular monomers, an initiator, a solvent and a molecular weight regulator, carrying out ultrasonic degassing treatment, injecting a precursor solution obtained through the treatment into a mold, carrying out thermal initiation reaction or photo-initiation reaction, carrying out solvent volatilization treatment on a polyelectrolyte elastomer precursor obtained after the mold stripping, and obtaining the polyelectrolyte glass. The polyelectrolyte elastomer monomers and the rigid high-molecular monomers, which are two components with completely different properties, are phase-separated on the micro or submicro scale, but each component is highly continuous in three-dimensional space, so that an extremely stable and interlocked double-continuous phase microstructure is formed, a double-continuous network skeleton is successfully constructed, and the polyelectrolyte glass is ensured to exhibit extremely high optical transparency on the macro level through the inhibition of light scattering effect.

Description

Technical Field

[0001] This invention relates to the field of polymer conductive materials technology, and in particular to a high-strength and high-toughness polyelectrolyte glass, its preparation method and application. Background Technology

[0002] In cutting-edge fields such as optoelectronic devices, smart windows, and electromagnetic shielding, conductive materials are facing increasingly stringent comprehensive performance requirements. These applications not only demand excellent optical transparency to meet the needs of visual sensing and optical signal transmission, but also require materials to possess superior mechanical properties (such as high strength and high toughness) and long-term structural stability to ensure reliable operation of devices under complex conditions. Simultaneously, to achieve antistatic, electromagnetic compatibility, or active sensing functions, materials must also possess stable and controllable conductivity. Therefore, developing advanced conductive materials with excellent comprehensive performance has become a major research hotspot in materials science.

[0003] Currently, mainstream transparent conductive materials still have significant limitations. In contrast, ionogels, as a new type of flexible ion-conductive material, exhibit unique advantages in optical transparency, deformation adaptability, and processability due to their ion transport mechanism, providing a new approach to breaking through the performance bottlenecks of traditional electronic conductors.

[0004] However, even though ionogels have great application potential, existing transparent conductive gels still have significant technical bottlenecks in actual service, especially when facing harsh and complex mechanical environments. These include: difficulty in balancing mechanical properties and optical transparency; an inherent contradiction between high strength and high toughness, making it difficult to meet extreme load-bearing requirements; and an irreconcilable contradiction between mechanical strength and conductivity.

[0005] Although recent studies have attempted to improve the mechanical properties of gels by constructing structures such as dual networks, these systems are prone to disordered macroscopic phase separation during polymerization if the compatibility between different mechanical and conductive components is not properly controlled, resulting in the gel turning white, becoming cloudy, and completely losing its transparency.

[0006] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a high-strength and high-toughness polyelectrolyte glass, its preparation method and application, in order to solve the problem that existing gel materials are difficult to achieve simultaneously with high strength, high toughness, high transparency and excellent conductivity.

[0008] The technical solution of the present invention is as follows: A method for preparing a high-strength and high-toughness polyelectrolyte glass includes the following steps: A precursor solution is obtained by mixing polyelectrolyte elastomer monomers, rigid polymer monomers, initiators, solvents and molecular weight regulators and then degassing the mixture using ultrasound. The precursor solution is injected into a mold, and after thermal or photo-initiated reaction, a polyelectrolyte elastomer precursor is obtained. The polyelectrolyte elastomer precursor is demolded and then subjected to solvent evaporation treatment to obtain polyelectrolyte glass.

[0009] The method for preparing the high-strength and high-toughness polyelectrolyte glass, wherein the polyelectrolyte elastomer monomer comprises at least one or more of 1-vinyl-3-butylimidazolium dicyanamide, acryloyloxyethyltrimethyldicyanamide, 1-butyl-3-methylimidazolium-3-sulfopropyl acrylate, 1-benzyl-3-vinylimidazolium, 1-(6-(acryloyloxy)-hexyl)-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide, and 2-acrylamido-2-methylpropanesulfonic acid.

[0010] The method for preparing the high-strength and high-toughness polyelectrolyte glass, wherein the rigid polymer monomer includes one or more of styrene, α-methylstyrene, acrylonitrile, N-vinylcarbazole, vinyltoluene, isobornyl methacrylate, and cyclohexyl methacrylate.

[0011] The method for preparing high-strength and high-toughness polyelectrolyte glass, wherein the initiator is a thermal initiator or a photoinitiator; Preferably, the thermal initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, potassium persulfate, azobisisobutyronitrile, N,N-dimethylaniline, and benzoyl peroxide; Preferably, the photoinitiator includes one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and benzophenone.

[0012] The method for preparing high-strength and high-toughness polyelectrolyte glass, wherein the solvent includes one or more of acetonitrile, polyethylene glycol, glycerol, glacial acetic acid, and ethanol; And / or, the molecular weight regulator includes one or more of dodecyl mercaptothiol, isooctyl mercaptoacetate, isooctyl 3-mercaptopropionate, and mercaptoacetic acid.

[0013] The method for preparing high-strength and high-toughness polyelectrolyte glass, wherein the molar ratio of the polyelectrolyte elastomer monomer to the rigid polymer monomer is (1:0.01)-(1:10).

[0014] The method for preparing high-strength and high-toughness polyelectrolyte glass, wherein in the precursor solution, the content of the solvent is 10wt%-50wt%, the content of the initiator is 0.1wt%-3wt%, and the content of the molecular weight regulator is 0-3wt%.

[0015] The method for preparing high-strength and high-toughness polyelectrolyte glass, wherein the temperature of the thermal initiation reaction is 50℃-80℃ and the time of the thermal initiation reaction is 8h-72h; And / or, the photoinitiation reaction is initiated by ultraviolet light with a wavelength of 365nm-405nm, and the photoinitiation reaction takes 3h-24h.

[0016] A high-strength and high-toughness polyelectrolyte glass is prepared using the aforementioned method.

[0017] Application of a high-strength and high-toughness polyelectrolyte glass in electronic packaging, transparent electromagnetic shielding, or optoelectronic devices.

[0018] Beneficial Effects: This invention provides a high-strength and high-toughness polyelectrolyte glass, its preparation method, and its application. The preparation method of the high-strength and high-toughness polyelectrolyte glass includes the following steps: mixing polyelectrolyte elastomer monomers, rigid polymer monomers, initiators, solvents, and molecular weight regulators, followed by ultrasonic degassing to obtain a precursor solution; injecting the precursor solution into a mold, followed by thermal or photoinitiation to obtain a polyelectrolyte elastomer precursor; and then subjecting the polyelectrolyte elastomer precursor to solvent evaporation treatment after demolding to obtain the polyelectrolyte glass. This invention utilizes the phase separation of two distinctly different component phases—polyelectrolyte elastomer monomers and rigid polymer monomers—at the microscopic or submicroscopic scale, while maintaining high continuity in three-dimensional space. This results in an extremely stable and interlocked bicontinuous phase microstructure. The formation mechanism of this unique structure mainly relies on the synergistic regulation of thermodynamic compatibility and polymerization kinetics. During the gel network formation process, the rigid polymer monomers with rigid polymer chains and the polyelectrolyte elastomer monomers with flexible polymer chains undergo microscopic phase separation. By precisely matching the crosslinking density and the phase separation rate, the phase region size is strictly limited to a level much smaller than the wavelength of visible light. This phase separation at this scale not only successfully constructs a bicontinuous network framework but also ensures that the polyelectrolyte glass exhibits extremely high optical transparency on a macroscopic scale by suppressing light scattering effects. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the process flow for a method of preparing high-strength and high-toughness polyelectrolyte glass according to the present invention. Figure 2 A photograph of the transparent polyelectrolyte glass block sample prepared in Example 1; Figure 3 Stress-strain curves of polyelectrolyte glasses with different molar ratios of mechanical and conductive phases at 80% humidity; Figure 4 Figure 1: Fracture tensile strength and fracture tensile strain data for polyelectrolyte glasses with different molar ratios of mechanical and conductive phases. Figure 5 A graph showing the yield strength data of polyelectrolyte glasses with different molar ratios of mechanical and conductive phases; Figure 6 A graph showing the fracture work data for polyelectrolyte glasses with different molar ratios of mechanical and conductive phases; Figure 7 Modulus characterization diagrams of polyelectrolyte glasses with different molar ratios of mechanical and conductive phases at different humidity levels; Figure 8 Transparency characterization diagrams of polyelectrolyte glass with a molar ratio of mechanical phase to conductive phase of 2:1 at different humidity levels; Figure 9 This is a diagram showing the transparency of polyelectrolyte glass when the molar ratio of the mechanical phase to the conductive phase is 2:1. Figure 10 A graph showing the conductivity data of polyelectrolyte elastomers with different ratios of mechanical and conductive phases under different humidity levels. Figure 11 A physical image demonstrating the conductivity of polyelectrolyte glass; Figure 12 This is an ETEM microstructure diagram of a polyelectrolyte glass with a molar ratio of 1:1 between the mechanical and conductive phases. Detailed Implementation

[0020] This invention provides a high-strength, high-toughness polyelectrolyte glass, its preparation method, and its applications. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0022] Traditional electronic conductors, represented by indium tin oxide (ITO), possess both high light transmittance and high conductivity, but are inherently brittle and extremely inflexible. They are prone to cracking and failure under bending, stretching, or vibration. Furthermore, indium resources are scarce and expensive, making it difficult to meet the needs of large-scale applications in flexible devices. To compensate for these shortcomings, nanoscale carbon-based and metal-based conductive materials such as silver nanowires, graphene, and carbon nanotubes are widely used to construct novel transparent conductive systems. These materials have improved conductivity and theoretical flexibility, but still have significant drawbacks: silver nanowires are prone to oxidation and electromigration, resulting in high interfacial contact resistance and poor long-term stability; graphene and carbon nanotubes suffer from poor dispersibility, easy aggregation, complex and costly fabrication processes, and difficulty in controlling the uniformity of large-area film formation. They also have weak bonding with the substrate interface, making them prone to detachment and cracking under complex mechanical loads, leading to a sharp decline in photoelectric performance.

[0023] While existing ionogels possess promising application potential, current transparent conductive gels still face significant technical bottlenecks in actual service, especially when exposed to harsh and complex mechanical environments. First, it is difficult to balance mechanical properties and optical transparency. Traditional conductive gels typically employ physical doping to introduce rigid nanofillers (such as carbon nanotubes, graphene, metal nanowires, or inorganic nanoparticles) to improve both mechanical strength and conductivity. While this strategy enhances the material's mechanical strength to some extent, the refractive index difference between the nanofiller and the gel matrix, as well as the agglomeration effect of the filler, inevitably leads to severe Rayleigh or Mie scattering. This results in a significant decrease in the gel's optical transparency, making it unsuitable for applications with stringent transmittance requirements, such as transparent touchscreens and invisible wearable devices.

[0024] Second, there is an inherent contradiction between high strength and high toughness, making it difficult to meet extreme load-bearing requirements. In various extreme service scenarios, gel materials often need to withstand high-amplitude compressive stress as well as complex tensile, tearing, and other multiaxial mechanical forces simultaneously. Traditional homogeneous network gels or single-network conductive gels generally face the limitation of being "strong but not tough" or "tough but not strong." When subjected to severe external mechanical impact or long-term cyclic deformation, due to the lack of an effective energy dissipation mechanism, such gels are prone to irreversible damage to their internal microstructure, leading to macroscopic fracture failure.

[0025] Third, there is an irreconcilable contradiction between mechanical strength and electrical conductivity. In traditional gel systems, to obtain high-strength mechanical support, it is usually necessary to significantly increase the crosslinking density of the polymer matrix or introduce a dense, rigid network. However, this highly dense and confined polymer network structure severely hinders the free migration of the internal conductive medium, leading to a significant decrease in the material's conductivity. Conversely, to pursue excellent electrical conductivity, it is often necessary to maintain a high proportion of flexible components, increase the water content, or maintain a relatively loose network structure to promote the flow of the conductive medium. However, this inevitably leads to the gel becoming soft and fragile, greatly weakening its load-bearing capacity and compressive strength. Therefore, gels with conventional network structures often struggle to balance mechanical strength and electrical conductivity.

[0026] How to break the mutual constraints between mechanical strength, optical transparency and conductivity by starting from the design of micro-network structure, and develop a new transparent conductive material with excellent comprehensive performance is a key technical problem that urgently needs to be solved in this field.

[0027] Based on this, such as Figure 1 As shown, this invention provides a method for preparing a high-strength and high-toughness polyelectrolyte glass, comprising the following steps: Step S10: Mix the polyelectrolyte elastomer monomer, rigid polymer monomer, initiator, solvent and molecular weight regulator, and then degas the mixture using ultrasound to obtain a precursor solution; Step S20: The precursor solution is injected into a mold, and after thermal initiation or photoinitiation, a polyelectrolyte elastomer precursor is obtained; Step S30: After demolding, the polyelectrolyte elastomer precursor is subjected to solvent evaporation treatment to obtain polyelectrolyte glass.

[0028] In this embodiment, two component phases with drastically different properties, polyelectrolyte elastomer monomer and rigid polymer monomer, undergo phase separation at the microscopic or submicroscopic scale, while maintaining high continuity in three-dimensional space. This results in an extremely stable and interlocked bicontinuous phase microstructure. The formation mechanism of this unique structure mainly relies on the synergistic regulation of thermodynamic compatibility and polymerization kinetics. During the gel network formation process, the rigid polymer monomer with rigid polymer chains and the polyelectrolyte elastomer monomer with flexible polymer chains undergo microscopic phase separation. By precisely matching the crosslinking density and the phase separation rate, the phase region size is strictly limited to a level much smaller than the wavelength of visible light. This phase separation at this scale not only successfully constructs a bicontinuous network framework but also ensures that the polyelectrolyte glass exhibits extremely high optical transparency on a macroscopic scale by suppressing light scattering effects.

[0029] Specifically, the preparation method provided by this invention uses rigid polymer monomers as the mechanical phase (i.e., hard phase) and polyelectrolyte elastomer monomers as the conductive phase (i.e., soft phase). The resulting high-strength and high-toughness polyelectrolyte glass has a dual continuous phase separation structure. By constructing an interlocking dual continuous phase network at the micro / submicro scale, it breaks the mutual exclusion limitation between macroscopic properties. Furthermore, the preparation method is process-controllable and easy to achieve large-scale preparation.

[0030] In some embodiments, the polyelectrolyte elastomer monomer comprises at least one or more of 1-vinyl-3-butylimidazolium dicyandiamide ([NVIM][DCN]), acryloyloxyethyltrimethyldicyandiamide (AC), 1-butyl-3-methylimidazolium-3-sulfopropyl acrylate (BS), 1-benzyl-3-vinylimidazolium ([BnVIm]Cl), 1-(6-(acryloyloxy)-hexyl)-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide ([EIC6A][TFSI]), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS). These polyelectrolyte elastomer monomers readily dissociate in solvents to release ionic groups that provide ionic conductivity, while also exhibiting a low local glass transition temperature and maintaining high chain flexibility.

[0031] In some embodiments, the rigid polymer monomer includes one or more of styrene (SM), α-methylstyrene (α-MS), acrylonitrile (AN), N-vinylcarbazole (NVC), vinyltoluene, isobornyl methacrylate (IBOMA), and cyclohexyl methacrylate (CHMA). The aforementioned rigid polymer monomers provide a robust rigid framework for the entire polyelectrolyte glass system and can form a bicontinuous phase-separated structure with the polyelectrolyte elastomer monomers, which are conductive components. Furthermore, the rigid polymer monomers and the polyelectrolyte elastomer monomer network exhibit appropriate thermodynamic incompatibility. Simultaneously, the rigid polymer monomers possess sufficiently large Flory-Huggins parameters to drive the formation of the phase-separated structure. Additionally, the refractive index of the rigid polymer monomers closely matches the refractive index of the conductive phase to maintain good transparency.

[0032] In some embodiments, the initiator is a thermal initiator or a photoinitiator; by selecting different initiators, different reactions can be used to prepare the polyelectrolyte elastic precursor, including thermal initiation reactions and photoinitiation reactions.

[0033] In some embodiments, the thermal initiator includes one or more of azobisisobutyronitrile (ABVN), benzoyl peroxide (BPO), potassium persulfate (KPS), azobisisobutyronitrile (AIBN), N,N-dimethylaniline (DMA), and benzoyl peroxide (BPO). The selection of these thermal initiators allows them to decompose and generate free radicals under heating conditions, effectively initiating free radical polymerization of monomers, significantly reducing the activation energy of the polymerization reaction, accelerating the polymerization rate, shortening the induction period, and enabling the polymerization process to proceed smoothly under relatively mild thermal conditions. These thermal initiators can be adapted to low-temperature, medium-temperature, and even high-temperature polymerization systems according to different decomposition temperatures, precisely controlling the onset temperature and reaction progress of the polymerization reaction. They also help control the molecular weight and distribution of the polymer, improving polymerization conversion and product uniformity. Some compound combinations can also form redox initiation systems, further broadening the applicable temperature range and enhancing initiation efficiency and reaction stability.

[0034] In some embodiments, the photoinitiator includes one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), 1-hydroxycyclohexylphenyl ketone (184), and benzophenone (BP). The aforementioned photoinitiator, when irradiated with ultraviolet or visible light, can rapidly absorb light energy and undergo a photochemical reaction, generating active species such as active free radicals, thereby efficiently initiating free radical polymerization and cross-linking curing reactions of unsaturated monomers and prepolymers. The aforementioned photoinitiator can rapidly initiate the photocuring process at room temperature or even low temperatures, significantly improving the curing rate, shortening the reaction time, achieving efficient and energy-saving instantaneous curing, while effectively controlling the curing depth and surface curing effect.

[0035] In some embodiments, the solvent includes one or more of acetonitrile (ACN), polyethylene glycol (PEG), glycerol (Gly), glacial acetic acid (AcOH), and ethanol (EtOH); the above solvents can provide a better reaction environment for thermally initiated or photoinitiated reactions, and after obtaining the polyelectrolyte elastomer precursor, solvent evaporation treatment is performed to obtain polyelectrolyte glass.

[0036] In some embodiments, the molecular weight regulator includes one or more of n-dodecyl mercaptan (NDM), isooctyl mercaptoacetate (IOTG), isooctyl 3-mercaptopropionate (IOMP), and mercaptoacetic acid (TGA). These molecular weight regulators can interact with growing chain radicals through efficient chain transfer reactions, promptly terminating the continuous growth of polymer molecular chains, thereby effectively controlling the polymer's molecular weight and avoiding problems such as excessively high viscosity and poor processability caused by excessively high molecular weight and wide distribution. Furthermore, these molecular weight regulators can significantly improve the polymer's molecular weight distribution, making it more uniform and controllable. Simultaneously, without significantly affecting the polymerization conversion rate and reaction rate, they can adjust the polymer's flowability, flexibility, film-forming properties, and mechanical properties, adapting to the viscosity, hardness, and crosslinking requirements of different application scenarios.

[0037] In some embodiments, the molar ratio of the polyelectrolyte elastomer monomer to the rigid polymer monomer is (1:0.01)-(1:10). Controlling the molar ratio of the polyelectrolyte elastomer monomer to the rigid polymer monomer within this range allows for the formation of an extremely stable and interlocked bicontinuous phase microstructure. The formation mechanism of this unique structure mainly relies on the synergistic regulation of thermodynamic compatibility and polymerization kinetics. During the gel network formation process, the rigid polymer monomer with rigid polymer chains and the polyelectrolyte elastomer monomer with flexible polymer chains undergo microscopic phase separation. By precisely matching the crosslinking density and the phase separation rate, the phase region size is strictly limited to a level much smaller than the wavelength of visible light. This phase separation at this scale not only successfully constructs the bicontinuous network framework but also ensures that the polyelectrolyte glass exhibits extremely high optical transparency on a macroscopic scale by suppressing light scattering effects.

[0038] In a preferred embodiment, the molar ratio of the polyelectrolyte elastomer monomer to the rigid polymer monomer can be, but is not limited to, 2:1, 1:1, 1:2, etc.

[0039] In some embodiments, the solvent content in the precursor solution is 10wt%-50wt%, the initiator content is 0.1wt%-3wt%, and the molecular weight regulator content is 0-3wt%. Controlling the contents of the solvent, initiator, and molecular weight regulator within these ranges allows for a synergistic balance between reaction rate, system viscosity, and polymer structure.

[0040] Specifically, an appropriate amount of solvent can effectively reduce the viscosity of the reaction system, improve material mixing and heat and mass transfer efficiency, avoid local overheating or gelation, and provide a suitable reaction environment for the polymerization reaction, ensuring stable reaction. An initiator addition of 0.1wt%-3wt% can ensure the smooth initiation of photo-initiation or thermal initiation processes, providing sufficient active free radicals to maintain a suitable polymerization rate and conversion rate, while avoiding problems such as excessive residue, low polymer molecular weight, or decreased thermal stability due to excessive initiator. The content of molecular weight regulators in the range of 0-3wt% can flexibly control the polymer chain length and molecular weight distribution, improving the material's flexibility, adhesion, and processing fluidity as needed. Too low a content will have little effect, while too high a content may excessively inhibit chain growth and reduce the degree of polymerization and crosslinking density.

[0041] In some embodiments, the temperature of the thermal initiation reaction is 50°C-80°C, and the time of the thermal initiation reaction is 8h-72h; at the above thermal initiation temperature and time, the precursor solution undergoes a free radical polymerization reaction in an oxygen-free environment to obtain a polyelectrolyte elastic precursor.

[0042] In a preferred embodiment, the temperature of the thermal initiation reaction is 60°C, and the duration of the thermal initiation reaction is 16 hours.

[0043] In some embodiments, the photoinitiation reaction is initiated by ultraviolet light irradiation with a wavelength of 365 nm to 405 nm, and the photoinitiation reaction time is 3 h to 24 h. Under the above-mentioned photoinitiation wavelength and time, the precursor solution undergoes a free radical polymerization reaction in an oxygen-free environment to obtain a polyelectrolyte elastic precursor.

[0044] In a preferred embodiment, the photoinitiation reaction is initiated by ultraviolet light with a wavelength of 380 nm, and the photoinitiation reaction takes 15 hours.

[0045] Specifically, the precursor solution is injected into a glass mold and reacted at 50℃-80℃ for 8h-72h or irradiated with ultraviolet light with a wavelength of 365nm-405nm for 3h-24h to induce the formation of a polymer skeleton, thereby initially forming a polyelectrolyte elastomer precursor with a tendency for micro-phase separation. Then, the polyelectrolyte elastomer precursor is fixed in a bicontinuous phase, and the above-mentioned polyelectrolyte elastomer precursor is demolded and subjected to solvent evaporation treatment to further improve the environmental reliability of the material. In this stage, the densification of the rigid skeleton and the continuous interlocking of the polyelectrolyte network are further induced and locked, and the initial network is finally transformed into a high-strength and high-toughness polyelectrolyte glass with complete solid or quasi-solid properties and ionic conductivity.

[0046] In addition, the present invention also provides a high-strength and high-toughness polyelectrolyte glass, which is prepared by the method for preparing the high-strength and high-toughness polyelectrolyte glass.

[0047] In this embodiment, the polyelectrolyte glass uses rigid polymer monomers as the mechanical phase (i.e., hard phase) and polyelectrolyte elastomer monomers as the conductive phase (i.e., soft phase). The high-strength and high-toughness polyelectrolyte glass provided has a dual continuous phase separation structure. By constructing an interlocking dual continuous phase network at the micro / submicro scale, it breaks the mutual exclusion restriction between macroscopic properties and successfully constructs a dual continuous network skeleton. Furthermore, by suppressing the light scattering effect, it ensures that the polyelectrolyte glass exhibits extremely high optical transparency on a macroscopic scale.

[0048] In addition, the present invention also provides the application of high-strength and high-toughness polyelectrolyte glass in electronic packaging, transparent electromagnetic shielding or optoelectronic devices.

[0049] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention.

[0050] Example 1 This embodiment provides a high-strength and high-toughness polyelectrolyte glass, the specific preparation of which includes the following: Cyclohexyl methacrylate (CHMA), the mechanical phase monomer, and 1-butyl-3-methylimidazolium-3-sulfopropyl acrylate (BS), the conductive phase monomer, were mixed in different molar ratios (1:0, 2:1, 1:1, 1:2 mol / mol). Based on the total mass of the final precursor solution, 0.5 wt% thermal initiator azobisisobutyronitrile (ABVN), 1 wt% molecular weight regulator n-dodecyl mercaptan (NDM), and 10 wt% solvent acetonitrile (ACN) were added and uniformly mixed. The mixture was then subjected to ultrasonic degassing to obtain a homogeneous and transparent precursor solution. The precursor solution was injected into a 10cm*10cm*2mm glass mold and reacted at 60°C for 16 hours in an oxygen-free environment to induce the formation of the polymer backbone, thus initially forming a polyelectrolyte elastomer precursor with a tendency for microphase separation. After demolding the polyelectrolyte elastomer precursor, the solvent was evaporated, ultimately yielding a high-strength and high-toughness polyelectrolyte glass with different molar ratios of the mechanical and conductive phases and varying ionic conductivity.

[0051] The polyelectrolyte glasses with different molar ratios of mechanical and conductive phases prepared in this embodiment were characterized as follows: 1) Macroscopic morphological characteristics of blocky samples A photograph of the transparent polyelectrolyte glass block sample prepared in this embodiment is shown below. Figure 2As shown in the photographs, the polyelectrolyte glass has a smooth and dense surface, with no internal bubbles and no visible macroscopic phase separation (turbidity or whitening). This indicates that during the preparation process, the size of the bicontinuous phase separation between the hard phase framework and the soft polyelectrolyte phase was successfully and stably confined to a scale much smaller than the wavelength of visible light, thus macroscopically endowing the bulk sample with excellent structural uniformity and high optical transparency.

[0052] 2) Mechanical property testing Polyelectrolyte glasses with different molar ratios of the four mechanical and conductive phases were cut into dumbbell shapes using a punching machine according to JIS-K6251-7 standard. Their tensile properties were tested using a universal tensile tester under 80% humidity conditions, and their stress-strain curves were obtained. Figure 3 As shown.

[0053] from Figure 3 Key mechanical parameters, including fracture tensile strength and fracture tensile strain, yield strength, and fracture work, are calculated and extracted from the stress-strain curves, as follows: The tensile strength and tensile strain at fracture of polyelectrolyte glasses with different molar ratios of mechanical and conductive phases are shown in the figure below. Figure 4 As shown in the figure, the yield strength data of polyelectrolyte glasses with different molar ratios of mechanical and conductive phases are as follows: Figure 5 As shown in the figure, the fracture work data of polyelectrolyte glasses with different molar ratios of mechanical and conductive phases are as follows: Figure 6 As shown. By Figure 4 It can be seen that as the proportion of the conductive phase (soft phase) increases, the tensile strength at break of the polyelectrolyte glass gradually decreases, while the tensile strain at break increases significantly, indicating that the material gradually transforms from a high-strength rigid state to a high-ductility flexible state. Combined with... Figure 5 It can be seen that the yield strength of the material also decreases with increasing conductive phase content, which is related to the flexibility provided by the soft phase network. Figure 6 The fracture work data shows that the purely mechanical phase has a high fracture work, while the fracture work first decreases and then increases significantly after introducing an appropriate amount of conductive phase; the fracture work reaches its highest value (approximately 8.2 MJ / m³) when the molar ratio of mechanical phase to conductive phase is 1:2. This fully demonstrates that in the microscopic bicontinuous phase network, a high content of flexible conductive phase can effectively dissipate the mechanical energy during fracture, thereby endowing polyelectrolyte glass with extremely excellent toughness.

[0054] Under different humidity conditions, the tensile properties of the above four polyelectrolyte elastomers were measured using a universal tensile tester. The tensile modulus was obtained by fitting the strain curves of the samples within the first 0-1% strain range. The results are as follows: Figure 7 As shown. By Figure 7It is known that the tensile modulus of purely mechanical phase materials is not sensitive to humidity changes, remaining at an extremely high level (approximately 1500 MPa) within a humidity range of 20%-95%. As the proportion of the conductive phase (soft phase) increases, the overall modulus of the material decreases, and its sensitivity to high humidity environments gradually increases. When the molar ratio of the mechanical phase to the conductive phase is 2:1, the material maintains excellent modulus stability below 80% relative humidity; however, when the conductive phase is dominant (e.g., 1:2), the modulus of the material shows a significant and sharp decrease after the humidity exceeds 60%. This is because water molecules enter the soft phase network under high humidity, producing a significant plasticizing effect. This indicates that by rationally designing the ratio of rigid to flexible phases (e.g., 2:1), excellent moisture resistance and mechanical load-bearing capacity can be achieved while ensuring a certain level of conductivity.

[0055] 3) Transparency test Transmittance tests were performed on a sample with a mechanical phase:conductive phase ratio of 2:1 under different humidity conditions using a UV-Vis spectrophotometer (METASH UV-8000). The transparency results are shown in the figure below. Figure 8 As shown. The thickness of all five test samples was 0.5 mm. Figure 9 As shown, the polyelectrolyte glass sample exhibits extremely high transparency with no obvious internal scattering. Figure 8 It is evident that within a relative humidity range of 20% to 80%, this polyelectrolyte glass exhibits excellent optical transmittance in the visible light band (400-800 nm), with transmittance consistently above 85%. This optically confirms that although phase separation occurs between the mechanical and conductive phases, the phase region size is strictly limited to a submicroscopic scale much smaller than the visible light wavelength, thus effectively suppressing light scattering at the interface. Figure 9 As can be seen from the actual product images, the material is as clear and transparent as glass on a macroscopic scale, which can fully meet the stringent requirements of optoelectronic devices and transparent packaging materials for high light transmittance.

[0056] 4) Conductivity test Polyelectrolyte glasses with different ratios of mechanical to conductive phases (2:1, 1:1, 1:2, 1:4) were surface-plated with gold. The resistance of the samples under different humidity levels was measured and fitted using a KEYSIGHT E4990A impedance analyzer. The formula was then used... Calculate the conductivity of the elastomer, where Indicates conductivity, L Indicates the length of the sample. A This represents the cross-sectional area of ​​the sample. R This indicates the resistance of the sample being measured.

[0057] The conductivity data of polyelectrolyte elastomers with different ratios of mechanical and conductive phases at different humidity levels are shown in the figure below. Figure 10 As shown. By Figure 10 It is evident that the conductivity of polyelectrolyte glass exhibits a significant positive correlation with both the conductive phase content and ambient humidity. Under any given humidity conditions, samples with a higher proportion of conductive phase demonstrate superior conductivity; for example, samples with a mechanical phase to conductive phase ratio of 1:2 exhibit the highest conductivity at all humidity levels. Furthermore, with increasing ambient humidity, the conductivity of samples at all ratios shows a leap across orders of magnitude. This is because, in the bicontinuous phase structure, the continuous soft-phase polyelectrolyte network absorbs water molecules from the environment. These water molecules not only promote the full dissociation of ionic groups but also further broaden ion transport channels, significantly enhancing ion mobility. This result demonstrates that the microscopic bicontinuous network constructed in this system not only does not hinder ion movement but also provides an efficient and unimpeded ion conduction pathway.

[0058] An external power supply (not directly shown) is connected to the polyelectrolyte glass body via two copper foil contacts on the right. The polyelectrolyte glass acts as a conductive medium connecting the external contacts and the embedded LED. A physical demonstration of the polyelectrolyte glass's conductivity is shown in the image below. Figure 11 As shown, current enters the polyelectrolyte glass from a copper foil contact, is transmitted through the continuous polyelectrolyte soft-phase network inside the polyelectrolyte glass, flows into one pin of the LED, drives the LED to emit light, and then returns from the other pin through the polyelectrolyte glass to another copper foil contact. The LED was successfully lit and emitted a clear green light, which visually confirms that the polyelectrolyte glass sample has excellent conductivity.

[0059] 5) Microstructure characterization Environmental transmission electron microscopy (ETEM) was performed on a polyelectrolyte glass with a mechanical phase to conductive phase ratio of 1:1. The ETEM microstructure images are shown below. Figure 12 As shown.

[0060] Prior to testing, the sample underwent ultrathin sectioning under vacuum. During the testing process, the sample remained in a vacuum environment, and no morphological changes due to liquid precipitation or evaporation were observed. The results showed the presence of microphase interfaces within the elastomer's internal structure, confirming the formation of a phase-separated structure.

[0061] In summary, this invention provides a high-strength and high-toughness polyelectrolyte glass, its preparation method, and its application. The preparation method of the high-strength and high-toughness polyelectrolyte glass includes the following steps: mixing polyelectrolyte elastomer monomers, rigid polymer monomers, initiators, solvents, and molecular weight regulators, followed by ultrasonic degassing to obtain a precursor solution; injecting the precursor solution into a mold, followed by thermal or photoinitiation to obtain a polyelectrolyte elastomer precursor; and then subjecting the polyelectrolyte elastomer precursor to solvent evaporation treatment after demolding to obtain the polyelectrolyte glass. This invention utilizes the phase separation of two distinctly different component phases—polyelectrolyte elastomer monomers and rigid polymer monomers—at the microscopic or submicroscopic scale, while maintaining high continuity in three-dimensional space. This results in an extremely stable and interlocked bicontinuous phase microstructure. The formation mechanism of this unique structure mainly relies on the synergistic regulation of thermodynamic compatibility and polymerization kinetics. During the gel network formation process, the rigid polymer monomers with rigid polymer chains and the polyelectrolyte elastomer monomers with flexible polymer chains undergo microscopic phase separation. By precisely matching the crosslinking density and the phase separation rate, the phase region size is strictly limited to a level much smaller than the wavelength of visible light. This phase separation at this scale not only successfully constructs a bicontinuous network framework but also ensures that the polyelectrolyte glass exhibits extremely high optical transparency on a macroscopic scale by suppressing light scattering effects.

[0062] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a high-strength and high-toughness polyelectrolyte glass, characterized in that, Including the following steps: A precursor solution is obtained by mixing polyelectrolyte elastomer monomers, rigid polymer monomers, initiators, solvents, and molecular weight regulators and then degassing the mixture using ultrasound. The precursor solution is injected into a mold, and after thermal or photo-initiated reaction, a polyelectrolyte elastomer precursor is obtained. The polyelectrolyte elastomer precursor is demolded and then subjected to solvent evaporation treatment to obtain polyelectrolyte glass.

2. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, The polyelectrolyte elastomer monomer includes at least one or more of the following: 1-vinyl-3-butylimidazolium dicyanamide, acryloyloxyethyltrimethyldicyanamide, 1-butyl-3-methylimidazolium-3-sulfopropyl acrylate, 1-benzyl-3-vinylimidazolium, 1-(6-(acryloyloxy)-hexyl)-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide, and 2-acrylamido-2-methylpropanesulfonic acid.

3. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, The rigid polymer monomers include one or more of styrene, α-methylstyrene, acrylonitrile, N-vinylcarbazole, vinyltoluene, isobornyl methacrylate, and cyclohexyl methacrylate.

4. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, The initiator is a thermal initiator or a photoinitiator; Preferably, the thermal initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, potassium persulfate, azobisisobutyronitrile, N,N-dimethylaniline, and benzoyl peroxide; Preferably, the photoinitiator includes one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxycyclohexylphenyl ketone, and benzophenone.

5. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, The solvent includes one or more of acetonitrile, polyethylene glycol, glycerin, glacial acetic acid, and ethanol; And / or, the molecular weight regulator includes one or more of dodecyl mercaptothiol, isooctyl mercaptoacetate, isooctyl 3-mercaptopropionate, and mercaptoacetic acid.

6. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, The molar ratio of the polyelectrolyte elastomer monomer to the rigid polymer monomer is (1:0.01)-(1:10).

7. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, In the precursor solution, the solvent content is 10wt%-50wt%, the initiator content is 0.1wt%-3wt%, and the molecular weight regulator content is 0-3wt%.

8. The method for preparing high-strength and high-toughness polyelectrolyte glass according to claim 1, characterized in that, The temperature of the thermal initiation reaction is 50℃-80℃, and the time of the thermal initiation reaction is 8h-72h; And / or, the photoinitiation reaction is initiated by ultraviolet light with a wavelength of 365nm-405nm, and the photoinitiation reaction takes 3h-24h.

9. A high-strength and high-toughness polyelectrolyte glass, characterized in that, It is prepared using the method for preparing high-strength and high-toughness polyelectrolyte glass as described in any one of claims 1-8.

10. The application of the high-strength and high-toughness polyelectrolyte glass as described in claim 9 in electronic packaging, transparent electromagnetic shielding, or optoelectronic devices.

Images