Preparation method of high-filling double-physical network composite gel with adjustable mechanical property

Abstract

The invention discloses a preparation method of high-filling double-physical network composite gel with adjustable mechanical property, which comprises the following steps: by taking ethylene glycol as a solvent, sequentially adding hydroxyethyl methylacrylate, vinylformamide and polyvinylpyrrolidone into the solvent, fully mixing the solution, adding azodiisobutyronitrile as an initiator, and after the azodiisobutyronitrile is completely dissolved, adding the initiator into the solvent to obtain the high-filling double-physical network composite gel with adjustable mechanical property. And adding solid particles, uniformly stirring, casting in a mold, and carrying out thermal-initiated free radical polymerization, so as to prepare the double-physical network composite gel. According to the method, agglomeration and sedimentation of solid particles in a mixed solution are prevented on the basis of interaction between polymer chains and the solid particles, the composite gel material is endowed with high mechanical performance and high elongation rate on the basis of intertwining and crosslinking of the polymer chains, and the high-filling composite gel material is developed. The preparation process is simple, the viscosity of a solid-liquid mixed system is adjustable, no strict requirement on the morphology of solid particles exists, various technological processes are adapted, and the obtained composite gel material has extremely high structural stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer material preparation, and relates to a method for preparing a composite gel material, in particular to a method for preparing a highly filled double physical network poly(hydroxyethyl methacrylate) / polyvinyl formamide / polyvinyl pyrrolidone) composite gel with widely adjustable mechanical properties. Background Art

[0002] Gels are functional polymer materials with three-dimensional network structures formed by crosslinking polymer chains through interactions such as covalent bonds, hydrogen bonds, van der Waals forces, and physical entanglement. Due to their excellent mechanical properties, biocompatibility, and environmental stability, they have broad application prospects in polymer materials science. Since the concept of composite gels was proposed, numerous researchers have added various inorganic fillers to the gel matrix to prepare composite gels with diverse functions. These composite gel materials exhibit remarkable mechanical, optical, and swelling properties while overcoming the limitations of traditional gel materials and have been successfully applied in various fields such as electronics, optics, sensors, and biomedicine. As flexible organic-inorganic two-phase composite materials, composite gels fully utilize the physicochemical properties of the gel and inorganic particles, as well as the synergistic effect between the two. However, to achieve good mechanical properties and excellent functionality, certain interactions between the gel matrix and the inorganic particles and a high inorganic particle loading are often required.

[0003] As the filling amount continues to increase, the van der Waals forces between particles increase, which easily forms irreversible aggregates and destroys uniformity; the compatibility of particles with the polymer network decreases, resulting in local enrichment or precipitation; the viscosity increases significantly, resulting in poor fluidity during injection molding and 3D printing; the particles hinder the slippage of polymer chains, and the material becomes brittle. The above problems will eventually cause fluctuations in mechanical properties and failure of functional sites. Due to the multifunctionality of composite gel materials, a single gel system is often difficult to possess. Therefore, in order to solve the above problems, in recent years, researchers have explored a variety of methods and approaches to prepare various multifunctional composite gel materials, including the use of cross-linking to prepare conductive sensing composite gels, the use of encapsulation to prepare magnetic responsive driver composite gels, and the use of the "breathing method" to prepare drug-controlled release composite gels.

[0004] Researchers have fabricated composite gels reinforced with graphene oxide (GO) and hexagonal boron nitride (hBN) as mixed fillers via compression molding. This composite gel mimics the layered structure of nacre and achieves high filler content without agglomeration (Composites Communications 2025, 56, 102389). A 10 wt% PVA solution was mixed with an hBN / IPA dispersion and stirred at 83°C (the boiling point of IPA) to completely evaporate the IPA. After the mixture cooled to room temperature, a GO solution was added and stirred for 1 hour to achieve a uniform dispersion. Finally, the ternary mixture was cast in a Teflon mold and dried under ambient conditions. GO enhances the mechanical properties of the composite gel, while a relatively small amount of hBN prevents GO agglomeration. Compared to pure PVA, the composite gel exhibits 787% and 106% increases in modulus and strength, respectively. However, this method has significant drawbacks. When the filler content reaches 80%, the mechanical properties of the composite gel are poor, with an elongation of only 1%, significantly limiting its application scenarios. Furthermore, this method involves liquid-phase exfoliation of the filler, making the process complex and the preparation costly. Furthermore, researchers have proposed a method for preparing anisotropic composite gel materials (Chemical Engineering Journal 2025, 514, 163202). N-isopropylacrylamide (NIPAM) is dissolved in 0.01 M phosphate-buffered saline (PBS). Specified amounts of N,N′-methylenebisacrylamide (MBAA), potassium persulfate (KPS), polydopamine nanoparticles (PDA NPs), and microgels are then added to the solution. After all components have dissolved, the mixture is purged with nitrogen for 5 minutes and reacted at room temperature for 24 hours to prepare the composite gel material. This composite gel integrates thermosensitive poly (N-isopropylacrylamide) (PNIPAM) to achieve heat-induced centripetal contraction, and also adds polydopamine nanoparticles (PDA NPs) and poly (styrenesulfonic acid methacrylate) -poly (acrylic acid) microgel (ZA microgel), which has strong adhesion and photothermal properties. However, the mechanical properties of the composite gel material prepared by this method are still poor, and it is easy to break when faced with large mechanical stress. In addition, the entire preparation process is relatively complicated and has high requirements for experimental conditions and equipment. The composite gel materials prepared by the above-reported methods are difficult to simultaneously take into account high filling content and high mechanical properties, and the elongation is low, which greatly limits the application scenarios. Summary of the Invention

[0005] In view of the problem that current composite gels are difficult to simultaneously accommodate high filling content and high mechanical properties, and that particles tend to agglomerate as the filling content increases, the present invention provides a method for preparing a high-filling dual-physical network composite gel with adjustable mechanical properties. This method is based on the way in which polymer chains and solid particles interact to prevent solid particles from agglomerating and settling in a mixed solution, and is based on the entanglement and cross-linking of polymer chains to impart high mechanical properties and high elongation to the composite gel material, thereby developing a high-filling composite gel material. The present invention uses hydroxyethyl methacrylate and vinylformamide as the first physical network and polyvinyl pyrrolidone as the second physical network to jointly construct a gel base, and ultimately prepares a high-filling composite gel material with high mechanical properties, wide adjustable range, uniform particle distribution, and high elongation. The preparation process of the present invention is simple, the viscosity of the solid-liquid mixing system is adjustable, there are no strict requirements on the morphology of the solid particles, it is adaptable to various process flows, and the obtained composite gel material has extremely high structural stability.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties comprises the following steps:

[0008] Step 1: Add hydroxyethyl methacrylate and vinyl formamide to a solvent and ultrasonically vibrate to fully dissolve them to obtain a hydroxyethyl methacrylate-vinyl formamide solution, wherein: the solvent is ethylene glycol, the mass concentration of hydroxyethyl methacrylate in the gel matrix is ​​6 to 15%, the mass concentration of vinyl formamide in the gel matrix is ​​3 to 20%, and the ultrasonic vibration time is 0.5 to 1.5 hours;

[0009] Step 2: Add polyvinyl pyrrolidone (PVP) to the solvent and ultrasonically vibrate to fully dissolve it to obtain a polyvinyl pyrrolidone solution, wherein: the solvent is ethylene glycol, the mass concentration of polyvinyl pyrrolidone in the gel matrix is ​​1-5%, and the ultrasonic vibration time is 0.5-1.5h;

[0010] Step 3: Adding polyvinyl pyrrolidone solution and initiator to the hydroxyethyl methacrylate-vinyl formamide solution obtained in step 1 in sequence, stirring thoroughly to mix evenly, wherein the initiator is an azo initiator, and the amount added is 2-4% of the total mass of hydroxyethyl methacrylate and vinyl formamide;

[0011] Step 4: adding solid particles in batches multiple times to the multi-component mixed solution obtained in step 3 to obtain a solid-liquid mixed system, wherein: the solid particles are one of zinc oxide, aluminum powder, ferroferric oxide, magnesium oxide, etc., and the solid filling amount is 70-85% of the total mass of the solid-liquid mixed system;

[0012] Step 5: Cast the solid-liquid mixed system obtained in step 4 into a mold, and place the mold in a drying oven for thermally initiated free radical polymerization to obtain a highly filled dual physical network poly(hydroxyethyl methacrylate) / polyvinyl formamide / polyvinyl pyrrolidone) composite gel with widely adjustable mechanical properties, wherein: the drying oven temperature is 60~80°C, and the thermally initiated free radical polymerization reaction time is 8~10h.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The composite gel material constructed by the present invention has a maximum solid particle filling amount of up to 85%, and the solid particles are evenly dispersed inside the gel (maintaining both macroscopic and microscopic uniformity) and have a certain stability.

[0015] 2. There is a certain hydrogen bond interaction between the hydroxyethyl methacrylate and vinylformamide used in the present invention and the solid particles, which not only prevents the solid particles from agglomerating, but also avoids the solid particles from settling in the mixed solution.

[0016] 3. During the preparation process of the composite gel material constructed in the present invention, the viscosity of the solid-liquid mixture system can be adjusted by adjusting the mass concentration of polyvinyl pyrrolidone to affect the interaction between hydroxyethyl methacrylate, vinyl formamide and solid particles, so as to adapt to various process flows.

[0017] 4. The composite gel material constructed by the present invention combines high filling content with high mechanical properties (high elongation, high toughness and certain strength), and the mechanical properties can be adjusted within a wide range, making it suitable for a variety of application scenarios.

[0018] 5. The mechanical properties of the composite gel material constructed by the present invention remain substantially unchanged after long-term storage, and the composite gel material has extremely high structural stability.

[0019] 6. The preparation process of the present invention is simple, has no stringent requirements on the solid particles to be filled, has a high yield, can be prepared on a large scale, and has commercial prospects.

[0020] 7. The present invention is expected to develop composite gel materials with high practical value in many fields, including but not limited to high solid content propellants, high conductivity strain sensors, fast magnetic response robots, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 These are actual pictures of the composite gel when the solid particle filling amount is 80% and the mass fraction of hydroxyethyl methacrylate is 6%, 9%, 12%, and 15%, actual pictures of the composite gel when the mass fraction of vinyl formamide is 6%, 9%, 12%, and 20%, as well as the corresponding elastic modulus and storage modulus curves.

[0022] Figure 2 This is the Fourier infrared spectrum of the double physical network gel without solid particles.

[0023] Figure 3 It shows the state and shear viscosity curve of the composite gel prepolymer solution when the solid particle filling amount is 70%, 80%, 83% and 85%.

[0024] Figure 4 This is the shear viscosity curve of the composite gel prepolymer solution when the solid particle filling amount is 80% and the mass fraction of polyvinyl pyrrolidone is 0%, 1%, 3%, and 5%.

[0025] Figure 5 It is a contact angle diagram between a multi-component mixed solution without solid particles and solid particles, as well as a diagram showing the change in contact angle with the mass fraction of polyvinyl pyrrolidone.

[0026] Figure 6 It is the actual picture of the composite gel prepolymer and the polymerized product when the solid particle filling amount is 80%, as well as the corresponding thermogravimetric curve.

[0027] Figure 7 These are the SEM images of the gel material without solid particles and the SEM images of the composite gel when the solid particle filling amount is 70%, 80%, and 83%.

[0028] Figure 8 This is the element distribution diagram (C, N, O, Zn) of the composite gel when the solid particle filling amount is 80%.

[0029] Figure 9 This is the uniaxial stress-strain curve of the composite gel when the solid particle filling amount is 80%, the mass fractions of hydroxyethyl methacrylate and vinyl formamide are 6%+0%, 9%+3%, 12+3%, and 15+12%, respectively, and the mass fraction of polyvinyl pyrrolidone is 3%.

[0030] Figure 10 This is a graph showing the stress-strain curve of the composite gel changing with time when the solid particle filling amount is 80%. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below with reference to the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0032] The present invention provides a method for preparing a high-filling dual physical network composite gel with adjustable mechanical properties. The method uses ethylene glycol as a solvent, and sequentially adds hydroxyethyl methacrylate, vinyl formamide, polyvinyl pyrrolidone (M w= 40000), after the solution is thoroughly mixed, an initiator is added. Once completely dissolved, solid particles are added, stirred evenly, and cast into a polytetrafluoroethylene mold. Free radical polymerization is initiated by heat at 60-80°C, thereby preparing a dual physical network composite gel with widely adjustable mechanical properties, a high solid particle loading, and uniform dispersion. The specific preparation steps are as follows:

[0033] Step 1: Add hydroxyethyl methacrylate and vinyl formamide to ethylene glycol solvent, and use an ultrasonic cleaning machine to ultrasonically vibrate for 0.5 to 1.5 hours to fully dissolve them to obtain a hydroxyethyl methacrylate-vinyl formamide-ethylene glycol (HEMA-NVF-EG) solution, wherein the mass concentration of hydroxyethyl methacrylate in the gel matrix is ​​6 to 15%, and the mass concentration of vinyl formamide in the gel matrix is ​​3 to 20%.

[0034] Step 2: Add polyvinyl pyrrolidone (PVP) to ethylene glycol solvent and use an ultrasonic cleaning machine to ultrasonically vibrate for 0.5 to 1.5 hours to fully dissolve it to obtain a polyvinyl pyrrolidone-ethylene glycol (PVP-EG) solution, wherein the mass concentration of polyvinyl pyrrolidone in the gel matrix is ​​1 to 5%.

[0035] Step 3: PVP-EG solution and initiator are added to the HEMA-NVF-EG solution obtained in step 1 in sequence, and stirred thoroughly to mix them evenly. At this time, the concentration of polymer chains in the mixed solution reaches the critical overlap concentration, wherein: the initiator is an azo initiator such as azobisisobutyronitrile, azobisisobutyramidine hydrochloride, and the addition amount is 2~4% of the total mass of hydroxyethyl methacrylate and vinylformamide.

[0036] Step 4: Add a certain amount of solid particles in batches multiple times (each addition amount is one-fourth of the total filling amount) to the multi-component mixed solution obtained in step 3, and after sufficient mechanical stirring, the solid particles are evenly distributed in the mixed solution to obtain a solid-liquid mixed system, wherein: the solid particles are one of zinc oxide, aluminum powder, ferroferric oxide, magnesium oxide, etc., and the solid filling amount is 70~85% of the total mass of the solid-liquid mixed system.

[0037] Step 5: Cast the solid-liquid mixture obtained in Step 4 into a polytetrafluoroethylene mold and place the mold in an electric-heated blast drying oven for thermally initiated free radical polymerization, resulting in a highly filled dual-physical network poly(hydroxyethyl methacrylate) / poly(vinyl formamide) / poly(vinyl pyrrolidone) composite gel with widely adjustable mechanical properties. The electric-heated blast drying oven temperature is 60-80°C, and the thermally initiated free radical polymerization reaction time is 8-10 hours. In this step, thermally initiated free radical polymerization converts hydroxyethyl methacrylate and vinyl formamide into long polymer chains. These chains become entangled, endowing the composite gel with excellent mechanical properties and high elongation. Furthermore, the interaction between the long polymer chains and the solid particles imparts good structural stability to the composite gel.

[0038] Example 1:

[0039] At room temperature and pressure, 128.76 mg + 0 mg, 193.14 mg + 64.38 mg, 257.52 mg + 64.38 mg, and 321.9 mg + 257.52 mg of hydroxyethyl methacrylate and vinyl formamide were added to 1.953 ml, 1.824 ml, 1.760 ml, and 1.502 ml of ethylene glycol solvent, respectively, and ultrasonic vibration was used to mix them evenly; 64.38 mg of polyvinyl pyrrolidone was added to the above four solutions, and ultrasonic vibration was continued to fully dissolve it; then 3.9 mg, 7.7 mg, 9.7 mg, and 17.4 mg of azobisisobutyronitrile were added to the above four mixed solutions, respectively, and mechanically stirred until the azobisisobutyronitrile was completely dissolved; 8.584 g of zinc oxide solid particles were added to the mixed solution in four times, with 2.146 After uniform mixing, the solid-liquid mixture was cast into a polytetrafluoroethylene mold. The mold was then placed in a 60°C electric forced-air drying oven for 9 hours to initiate thermal polymerization. The prepared composite gel was removed from the mold to obtain composite gel materials with a solids filling of 80% and varying mechanical properties.

[0040] Example 2:

[0041] At room temperature and pressure, 128.76 mg + 128.76 mg of hydroxyethyl methacrylate and vinyl formamide were added to 1.888 ml, 1.876 ml, 1.824 ml and 1.781 ml of ethylene glycol solvent, respectively, and ultrasonic vibration was used to mix them evenly; then 0 mg, 21.46 mg, 64.38 mg and 107.3 mg of polyvinyl pyrrolidone were added to the above four solutions, respectively, and ultrasonic vibration was used to fully dissolve them; after complete dissolution, 8.584 g of zinc oxide solid particles were added to the four mixed solutions, and the mixture was fully stirred to disperse them evenly, thereby obtaining a prepolymer solution with a solid filling amount of 80% and a polyvinyl pyrrolidone mass concentration of 0%, 1%, 3% and 5%.

[0042] Example 3:

[0043] At room temperature and pressure, 128.76 mg of hydroxyethyl methacrylate, 128.76 mg of vinylformamide and 64.38 mg of polyvinylpyrrolidone were added to 1.643 ml of ethylene glycol solvent and ultrasonically shaken to mix them evenly; then 5.008 g, 8.584 g, 10.477 g and 12.160 g of zinc oxide solid particles were added to the mixed solution, and stirred thoroughly to make them evenly dispersed, to obtain prepolymer solutions with solid filling amounts of 70%, 80%, 83% and 85%.

[0044] Example 4:

[0045] At room temperature and pressure, 128.76 mg, 193.14 mg, 257.52 mg and 321.9 mg of hydroxyethyl methacrylate were added to 1.817 ml, 1.759 ml, 1.701 ml and 1.643 ml of ethylene glycol solvent respectively; 128.76 mg, 193.14 mg, 257.52 mg and 429.2 mg of vinylformamide were added to 1.817 ml, 1.759 ml, 1.701 ml and 1.547 ml of ethylene glycol solvent respectively, and ultrasonic vibration was used to mix them evenly; then 3.9 mg, 5.8 mg, 7.7 mg and 9.6 mg of azobisisobutyronitrile were added to the hydroxyethyl methacrylate solution, and 3.9 mg, 5.8 mg, 7.7 mg and 12.9 mg of azobisisobutyronitrile were added to the hydroxyethyl methacrylate solution, and 3.9 mg, 5.8 mg, 7.7 mg and 12.9 mg of azobisisobutyronitrile were added to the hydroxyethyl methacrylate solution. mg of azobisisobutyronitrile was added to a vinylformamide solution and mechanically stirred until the azobisisobutyronitrile was completely dissolved. Then, 8.584 g of zinc oxide solid particles were added to the eight mixed solutions in four 2.146 g portions. After stirring, the solid-liquid mixture was cast into a polytetrafluoroethylene mold and thermally polymerized in a 60°C electric forced air drying oven for 9 hours. Composite gels with hydroxyethyl methacrylate mass fractions of 6%, 9%, 12%, and 15%, and vinylformamide mass fractions of 6%, 9%, 12%, and 20%, were prepared, with a solid loading of 80%.

[0046] Example 5:

[0047] The difference between this embodiment and embodiments 1-4 is that the solid particles are aluminum powder, ferrosoferric oxide or magnesium oxide.

[0048] Depend on Figure 1 As can be seen, the first row shows composite gel materials prepared with an 80% zinc oxide filling and varying concentrations of hydroxyethyl methacrylate. The gel shape is stable, and the elasticity of the composite gel material gradually increases with increasing hydroxyethyl methacrylate concentration. The second row shows composite gel materials prepared with an 80% zinc oxide filling and varying concentrations of vinyl formamide. The gel shape is difficult to stabilize. This indicates that the interaction between hydroxyethyl methacrylate and the zinc oxide solid particles is stronger, while the interaction between vinyl formamide and the zinc oxide solid particles is weaker.

[0049] Figure 2 This is the Fourier infrared spectrum of the double physical network gel without solid particles. For PVP, the stretching vibration peak of C=O (carbonyl) in the pyrrolidone ring appears at 1655 cm -1 For HEMA / EG gel, the stretching vibration peak of C=O (carbonyl) appears at 1724 cm -1 In HEMA / PVP / EG gel, the carbonyl stretching vibration peak of HEMA shifted from 1724 cm-1 Shifted to 1729 cm -1 The carbonyl stretching vibration peak of PVP is from 1655 cm -1 Shifted to 1660 cm -1 For HEMA / NVF / EG gel, the NH bond stretching vibration absorption peak appears at 3284 cm -1 The carbonyl stretching vibration peak of HEMA is from 1724 cm -1 Shifted to 1731 cm -1 , while the stretching vibration absorption peak of NH bond in HEMA / NVF / PVP / EG gel shifted from 3284 cm -1 Shift to 3280 cm -1 The above results demonstrate that there are obvious hydrogen bond interactions between the two physical networks, which entangle and cross-link with each other.

[0050] Depend on Figure 3 It can be seen that the state of the prepolymer solution becomes more viscous as the solid filling amount increases. At low shear rates, the molecular chains in the prepolymer solution are stretched by the shear flow, and the molecular structure is transformed into an ordered state, resulting in increased fluidity and shear-thinning behavior. As the shear rate increases, the probability of contact and collision between molecular chains increases, resulting in stronger intermolecular forces, which increases the viscosity of the fluid and exhibits shear-thickening behavior.

[0051] Depend on Figure 4 It can be seen that the viscosity of the solid-liquid mixture changes with the concentration of polyvinylpyrrolidone. As the concentration of polyvinylpyrrolidone increases, the viscosity of the solid-liquid mixture first decreases and then increases. When the concentration of polyvinylpyrrolidone increases, the interaction between hydroxyethyl methacrylate and vinylformamide and the solid particles is disrupted, resulting in a decrease in the viscosity of the system. As the concentration of polyvinylpyrrolidone continues to increase, the concentration of polymer chains in the solid-liquid mixture increases, leading to an increase in the overall viscosity of the system. These results indicate that the viscosity of the solid-liquid mixture can be adjusted by varying the concentration of polyvinylpyrrolidone.

[0052] Depend on Figure 5 It can be seen that the contact angle between the multi-component mixed solution and the solid particles is less than 40°, indicating that the affinity between the mixed solution and the solid particles is strong; with the increase of the concentration of polyvinyl pyrrolidone in the mixed solution, the contact angle gradually increases, indicating that the addition of polyvinyl pyrrolidone destroys the interaction between hydroxyethyl methacrylate and vinyl formamide and the solid particles.

[0053] Depend on Figure 6It can be seen that the solid particles do not settle or aggregate after being left in the prepolymer solution for a long time, and the solid particles in the solid-liquid mixed system do not settle or aggregate during the polymerization process. From a macroscopic perspective, this proves the uniform distribution of the solid particles in the composite gel material.

[0054] Figure 7 The following are SEM images of the gel material without solid particles and of the composite gel with zinc oxide solid particle loadings of 70%, 80%, and 83%. All samples were first frozen solid in liquid nitrogen and then freeze-dried in a freeze dryer. The SEM images of the gel material without solid particles show that the gel network is entangled and cross-linked, with a dense pore structure that is well suited for supporting solid particles. The SEM images of the gel material with solid particles show that the solid particles are densely and evenly arranged due to the interaction between the solid particles and the polymer network.

[0055] Figure 8 This is the element distribution diagram of the composite gel when the zinc oxide solid particle filling content is 80%. The figure shows that the four elements C, N, O, and Zn are evenly distributed, indicating that both the polymer network and the filled zinc oxide solid particles are evenly distributed in the composite gel.

[0056] Figure 9 The stress-strain diagram of the composite gel prepared by adding different concentrations of hydroxyethyl methacrylate and vinyl formamide when the zinc oxide solid particle filling amount is 80%. It can be seen from the figure that the maximum elongation of the composite gel can reach 650%, and the mechanical properties of the composite gel will change with the change of the concentration of hydroxyethyl methacrylate and vinyl formamide. The toughness of the composite gel can be between 0.03 and 2.04 MJ / m 3 The mechanical properties of the prepared composite gel material can be adjusted within a wide range, and the strength can be adjusted within a range of 61~665kPa.

[0057] Figure 10 The stress-strain curve of the composite gel with an 80% zinc oxide solid particle loading is plotted over time. The figure shows that the stress-strain curve of the composite gel material remains almost unchanged after one month of storage, demonstrating its excellent structural stability.

Claims

1. A method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties, characterized in that The method comprises the following steps: Step 1: Add hydroxyethyl methacrylate and vinyl formamide to a solvent and ultrasonically dissolve them to obtain a hydroxyethyl methacrylate-vinyl formamide solution, wherein the mass concentration of hydroxyethyl methacrylate in the gel matrix is ​​6 to 15%, and the mass concentration of vinyl formamide in the gel matrix is ​​3 to 20%. Step 2: adding polyvinyl pyrrolidone to a solvent and subjecting it to ultrasonic vibration to fully dissolve it to obtain a polyvinyl pyrrolidone solution, wherein the mass concentration of polyvinyl pyrrolidone in the gel matrix is ​​1-5%; Step 3: Adding polyvinyl pyrrolidone solution and initiator to the hydroxyethyl methacrylate-vinyl formamide solution obtained in step 1 in sequence, stirring thoroughly to mix evenly, wherein the amount of initiator added is 2-4% of the total mass of hydroxyethyl methacrylate and vinyl formamide; Step 4: adding solid particles in batches multiple times to the multi-component mixed solution obtained in step 3 to obtain a solid-liquid mixed system, wherein: the solid filling amount is 70-85% of the total mass of the solid-liquid mixed system; Step 5: Cast the solid-liquid mixed system obtained in step 4 into a mold, and place the mold in a drying oven to perform a thermally initiated free radical polymerization reaction to obtain a highly filled dual physical network poly(hydroxyethyl methacrylate) / polyvinyl formamide / polyvinyl pyrrolidone) composite gel.

2. The method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties according to claim 1, characterized in that In the step 1, the solvent is ethylene glycol, and the ultrasonic oscillation time is 0.5 to 1.5 hours.

3. The method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties according to claim 1, characterized in that In the step 2, the solvent is ethylene glycol, and the ultrasonic oscillation time is 0.5 to 1.5 hours.

4. The method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties according to claim 1, characterized in that In the step 3, the initiator is an azo initiator.

5. The method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties according to claim 1, characterized in that The azo initiator is azobisisobutyronitrile or azobisisobutyramidine hydrochloride.

6. The method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties according to claim 1, characterized in that In the step 4, the solid particles are one of zinc oxide, aluminum powder, ferroferric oxide, and magnesium oxide.

7. The method for preparing a highly filled dual physical network composite gel with adjustable mechanical properties according to claim 1, characterized in that In the step 4, the drying oven temperature is 60-80° C., and the thermally initiated free radical polymerization reaction time is 8-10 hours.

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