A high-toughness ionic gel and a preparation method thereof

Abstract

The present application relates to a kind of high tough ionic gel and its preparation method.The method includes the following steps: first, glycol is mixed with polyvinyl alcohol, and polyvinyl alcohol organic gel is formed by freezing technology.Subsequently, the formed organic gel is immersed in ionic liquid for salting-out treatment, and polyvinyl alcohol ionic gel is obtained.The ionic gel exhibits excellent mechanical properties, flexibility and energy absorption characteristics.Compared with traditional polyvinyl alcohol organic gel, its toughness and strength are significantly improved, and it shows excellent impact resistance, suitable for the development of bulletproof materials.

Description

Technical Field

[0001] This invention belongs to the technical field of high-strength and tough polymer materials, specifically relating to a high-strength and tough ionogel and its preparation method. The ionogel is a high-strength and tough organic ionogel with impact resistance, puncture resistance, and bullet resistance. Background Technology

[0002] In recent years, with the continuous advancement of science and technology and the increasing demand for high-performance materials, high-strength and high-toughness polymer materials have gradually attracted widespread attention. These materials not only have important applications in structural materials but also demonstrate great potential in flexible electronics, medical devices, and protective materials. Among them, ionogels, as a novel functional material, have become a research hotspot due to their excellent mechanical properties, flexibility, and good electrical conductivity. However, traditional gels still have many shortcomings in terms of strength and toughness, limiting their use in demanding applications.

[0003] Traditional hydrogels are widely used in medical dressings and tissue engineering due to their excellent biocompatibility and simple preparation process. However, hydrogels have poor mechanical properties and structural stability. In the prior art, Chinese patent CN114350080A discloses a hydrogel sensor and its preparation method, which improves the sensitivity to weak pressure by constructing microstructures on the surface of the hydrogel, but still has shortcomings in mechanical properties and impact resistance.

[0004] Based on currently available patents, research on high-strength and tough ionogel materials that simultaneously possess excellent mechanical properties and structural stability is still relatively limited. Developing high-strength and tough ionogel materials will not only further promote their application in bulletproof materials and flexible electronic devices, but also meet the urgent needs of more fields for high-performance materials. Summary of the Invention

[0005] This invention proposes an innovative gel strengthening strategy. By introducing ethylene glycol into a polyvinyl alcohol matrix and employing low-temperature freeze-crystallization and ionic liquid salting-out treatment, the strength and toughness of the gel are significantly improved. Through systematic research on the preparation process and properties, this invention provides new ideas and technical support for the development and application of high-performance ionogel materials.

[0006] Specifically, the present invention is achieved through the following technical solution:

[0007] A high-strength and tough ionogel is a product obtained by polymerizing ethylene glycol and polyvinyl alcohol at 70-160 degrees Celsius, freezing and crystallizing at -80 to -20 degrees Celsius, and finally fixing-salting out / direct-salting out at 0-100 degrees Celsius.

[0008] Furthermore, the high-strength and tough ionogel is a product obtained by polymerizing ethylene glycol and polyvinyl alcohol at 70-160 degrees Celsius (e.g., 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155 or 160 degrees Celsius), and then freezing and crystallizing it at -80 to -20 degrees Celsius (e.g., -80, -75, -70, -60, -50, -40, -30 or -20 degrees Celsius).

[0009] A method for preparing any of the high-strength and tough ionogels described above, the method comprising the following steps:

[0010] a) Mix polyvinyl alcohol and ethylene glycol at 70-160 degrees Celsius for 1-6 hours to obtain a homogeneous solution;

[0011] b) Pour the mixed solution obtained in step a) into a mold and freeze it at -80 to -20 degrees Celsius for 1 to 72 hours to obtain an organic ionic gel;

[0012] c) Place the organic ionic gel from step b) into 1-400 mL of ionic liquid for fixation-salting-out or direct-salting-out to obtain a high-strength and tough ionic gel.

[0013] Further, in step a), the mass ratio of ethylene glycol to polyvinyl alcohol is 1 to 50:1. For example, the mass ratio of ethylene glycol to polyvinyl alcohol is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 30:1, 40:1, or 50:1.

[0014] Further, in step c), the ionic liquid is an amino acid salt ionic liquid, an imidazole salt ionic liquid, a pyridine salt ionic liquid, or a phospholipid salt ionic liquid; preferably, the ionic liquid is an imidazole salt ionic liquid; preferably, the ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate.

[0015] Furthermore, in step c), the fixation-salting-out of the high-strength and tough ionic gel is carried out by stretching the gel by 0% to 500%, fixing it to an acrylic plate with clips, and then immersing it in an ionic liquid.

[0016] Furthermore, in step c), the direct salting-out of the high-strength and tough ionic gel is performed by directly immersing the gel in an ionic liquid.

[0017] Further, in step c), the volume ratio of the ionic liquid to the organic gel is 1 to 40:1; preferably, the volume ratio of the ionic liquid to the organic gel is 10:1; preferably, the volume ratio of the ionic liquid to the organic gel is 20:1; even more preferably, the volume ratio of the ionic liquid to the organic gel is 30:1; more preferably, the volume ratio of the ionic liquid to the organic gel is 40:1.

[0018] In one embodiment of the present invention, the high-strength and tough ionogel has excellent mechanical properties, with a strength of 27.74 MPa, which is 15.4 times that before salting out, and a toughness of 133.96 MPa / m³, which is 24.3 times that before salting out.

[0019] In one embodiment of the present invention, the high-strength and tough ionogel has a maximum static puncture force of 110.31 N / m and a maximum puncture energy of 1.40 J / m.

[0020] In one embodiment of the present invention, the high-strength and tough ionogel has a maximum dynamic puncture force of 259.31 N / m and a maximum puncture energy of 2.93 J / m.

[0021] In one embodiment of the present invention, the high-strength and tough ionogel is a product obtained by polymerizing ethylene glycol and polyvinyl alcohol at 70~160 degrees Celsius, then freezing and crystallizing at -20~-80 degrees Celsius, and finally fixing-salting out / direct-salting out at 0~100 degrees Celsius.

[0022] In one embodiment of the present invention, the fixation-salting-out of the high-strength and tough ionic gel is carried out by stretching the gel by 0% to 500%, fixing it to an acrylic plate with clips, and then immersing it in an ionic liquid.

[0023] In one embodiment of the present invention, the direct salting-out of the high-strength and tough ionic gel is performed by directly immersing the gel in an ionic liquid.

[0024] In one embodiment of the present invention, a high-strength and tough ionogel specifically refers to a high-strength and tough organic ionogel with impact resistance, puncture resistance, and bullet resistance, and its preparation method includes the following steps:

[0025] (1) Mix polyvinyl alcohol and ethylene glycol at 70-160 degrees Celsius for 1-6 hours to obtain a mixed solution;

[0026] (2) Pour the mixture obtained in step 1) into a mold and freeze it at -80 to -20 degrees Celsius for 1 to 72 hours to obtain an organic ionic gel;

[0027] (3) The organic ionic gel from step 2) is placed in 1-400 ml of ionic liquid for fixation-salting-out or direct-salting-out to obtain a high-strength and tough ionic gel.

[0028] In one embodiment of the present invention, the high-strength and tough ionogel has an ethylene glycol to polyvinyl alcohol mass ratio of 1 to 50:1; preferably, the ethylene glycol to polyvinyl alcohol mass ratio is 20:1; more preferably, the ethylene glycol to polyvinyl alcohol mass ratio is 10:1; even more preferably, the ethylene glycol to polyvinyl alcohol mass ratio is 20:3; more preferably, the ethylene glycol to polyvinyl alcohol mass ratio is 5:1; even more preferably, the ethylene glycol to polyvinyl alcohol mass ratio is 4:1.

[0029] In one embodiment of the present invention, the high-strength and tough ionic gel has a volume ratio of ionic liquid to organic gel of 1 to 40:1; preferably, the volume ratio of ionic liquid to organic gel is 10:1; more preferably, the volume ratio of ionic liquid to organic gel is 20:1; even more preferably, the volume ratio of ionic liquid to organic gel is 30:1; and more preferably, the volume ratio of ionic liquid to organic gel is 40:1.

[0030] Beneficial effects:

[0031] This invention discloses a high-strength and tough ionogel and its preparation method. The prepared high-strength and tough ionogel has excellent mechanical properties, including a strength of 27.74 MPa and a toughness of 133.96 MPa / m³, which are 15.4 times and 24.3 times that before salting out, respectively; the maximum static puncture force is 110.31 N / m and the maximum puncture energy is 1.40 J / m; the maximum dynamic puncture force is 259.31 N / m and the maximum puncture energy is 2.93 J / m. Attached Figure Description

[0032] Figure 1 The tensile stress-strain curves of the high-strength and tough ionogel before and after salting out;

[0033] Figure 2 Tensile stress-strain curves of salting-out of high-strength and tough ionogels under different pre-stretching conditions;

[0034] Figure 3 Tensile stress-strain curves of salting-out of high-strength and tough ionogels in different salt solutions;

[0035] Figure 4The static puncture resistance curve of the high-strength and tough ionogel;

[0036] Figure 5 This is a dynamic puncture resistance curve of a high-strength and tough ionogel. Detailed Implementation

[0037] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0038] A. The specific method for measuring the tensile properties of iontophores is as follows:

[0039] Tensile tests were performed on the MTS (MTS Standard 43). For the tensile test, the ionogel dimensions were 60 × 10 × 0.5 mm. During the test, the tensile rate was set to one-thousandth of the effective length of the sample (e.g., ...). Figure 1 , Figure 2 , Figure 3 ).

[0040] B. The specific method for measuring the static puncture resistance of iontophoresis gels is as follows:

[0041] A quasi-static puncture test was performed on the MTS device (MTS Standard 43). A rod-shaped loading head (diameter: 4 mm) with a hemispherical end approached the center of the sample at a constant velocity of 10 µm / s until penetration (e.g., ...). Figure 4 ).

[0042] C. The specific method for measuring the dynamic puncture resistance of iontophoresis gels is as follows:

[0043] A drop impact test was conducted on a drop hammer apparatus (ZCJ1302-a, MTS, USA). A rod-shaped impactor with a hemispherical end (diameter: 5 mm, 0.796 kg) was dropped freely from a height of 30 cm toward the center of the sample. The impact force-displacement curve was calculated based on the acceleration signal. The thickness of the polyvinyl alcohol ionomer gel was measured using a digital micrometer (Sanliang Company, 0-25 mm). Figure 5 ).

[0044] In this embodiment and its comparative examples, polyvinyl alcohol was used as the matrix. This polyvinyl alcohol was produced by Aladdin and had a molecular weight of 205,000.

[0045] Example 1:

[0046] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0047] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel.

[0048] Example 2:

[0049] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0050] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0051] (3) The organic gel from step (2) was placed in 400 mL of 1-butyl-3-methylimidazolium tetrafluoroborate for direct salting out to obtain a high-strength and tough ion gel.

[0052] Example 3:

[0053] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0054] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0055] (3) The organic gel in step (2) was pre-stretched by 0%, fixed on an acrylic plate with a clip, and placed in 400 ml of 1-butyl-3-methylimidazolium tetrafluoroborate for fixation-salting-out to obtain a high-strength and tough ion gel.

[0056] Example 4:

[0057] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0058] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0059] (3) The organic gel in step (2) is pre-stretched by 25%, fixed on an acrylic plate with a clip, and placed in 400 ml of 1-butyl-3-methylimidazolium tetrafluoroborate for fixation-salting-out to obtain a high-strength and tough ion gel.

[0060] Example 5:

[0061] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0062] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0063] (3) The organic gel in step (2) is pre-stretched by 50%, fixed on an acrylic plate with a clip, and placed in 400 ml of 1-butyl-3-methylimidazolium tetrafluoroborate for fixation-salting out to obtain a high-strength and tough ion gel.

[0064] Example 6:

[0065] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0066] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0067] (3) The organic gel in step (2) was pre-stretched by 75%, fixed on an acrylic plate with a clip, and placed in 400 ml of 1-butyl-3-methylimidazolium tetrafluoroborate for fixation-salting out to obtain a high-strength and tough ion gel.

[0068] Example 7:

[0069] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0070] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0071] (3) The organic gel in step (2) is pre-stretched by 0%, fixed on an acrylic plate with a clip, and placed in 400 ml of saturated sodium chloride for fixation-salting out to obtain a high-strength and tough ion gel.

[0072] Example 8:

[0073] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0074] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0075] (3) The organic gel in step (2) is pre-stretched by 0%, fixed on an acrylic plate with a clip, and placed in 400 ml of saturated sodium citrate for fixation-salting out to obtain a high-strength and tough ion gel.

[0076] Example 9:

[0077] (1) Mix 25 g of polyvinyl alcohol and 100 ml of ethylene glycol at 130 degrees Celsius for 3 hours to obtain a mixed solution;

[0078] (2) Pour the mixture obtained in step (1) into a mold and freeze it at -25 degrees Celsius for 12 hours to obtain an organic gel;

[0079] (3) The organic gel in step (2) is pre-stretched by 0%, fixed on an acrylic plate with a clip, and placed in 400 ml of saturated ammonium sulfate for fixation-salting out to obtain a high-strength and tough ion gel.

[0080] Figure 1 Tensile stress-strain curves of the organic gels and ionogels prepared in Examples 1-3 are shown. The ionogel of Example 3 exhibits the best mechanical properties, showing a high tensile strength of 27.74 MPa and a toughness of 133.96 MJ / m³.

[0081] Figure 2 The tensile stress-strain curves of ionomers prepared with different pre-stretching salting-out conditions in Examples 3-6 are shown. With increasing pre-stretching degree, the Young's modulus and strength of the ionomers continuously increase, while the fracture strain decreases accordingly.

[0082] Figure 3 Tensile stress-strain curves of ionomers prepared with different salt solutions in Examples 3 and 7-9 are shown. The results show that the ionomer prepared with 1-butyl-3-methylimidazolium tetrafluoroborate exhibits the strongest mechanical properties. This indicates that the choice of salt solution has a significant impact on the final mechanical properties of the ionomer, and that salting out with 1-butyl-3-methylimidazolium tetrafluoroborate is an effective choice for improving the performance of ionomers.

[0083] Figure 4 The figure shows a static puncture image comparing the high-strength and tough ionomer gels prepared in Examples 2 and 3 with Kevlar. The image indicates that the ionomer gel of Example 3 performs better in terms of static puncture resistance and energy dissipation, exceeding the performance of Kevlar.

[0084] Figure 5 The images show dynamic puncture resistance diagrams comparing the high-strength and tough ionogels prepared in Examples 2 and 3 with Kevlar fibers. The diagrams demonstrate that the ionogel in Example 3 exhibits higher dynamic puncture resistance and energy dissipation. The fixed-salting-out ionogel demonstrates superior puncture resistance, far exceeding that of Kevlar fibers of the same thickness. This superior puncture strength is primarily attributed to the highly entangled structure formed by the polyvinyl alcohol chains during the salting-out process.

[0085] In summary, this invention provides new ideas and technical support for the development and application of high-performance ionogel materials. This novel high-strength and high-toughness ionogel material will demonstrate great potential in bulletproof materials, flexible electronic devices, and other demanding applications.

[0086] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength and tough ionogel, characterized in that: The high-strength and tough ionogel is a product obtained by polymerizing ethylene glycol and polyvinyl alcohol at 70~160 degrees Celsius, freezing and crystallizing at -80~-20 degrees Celsius, and finally fixing and salting out at 0~100 degrees Celsius. The mass ratio of ethylene glycol to polyvinyl alcohol in the high-strength and tough ionogel is 1~50:1; The high-strength and tough ionogel is a product obtained by polymerizing ethylene glycol and polyvinyl alcohol at 130 degrees Celsius, then freezing and crystallizing at -25 degrees Celsius, and finally fixing and salting out at 40 degrees Celsius. The fixation-salting-out of the high-strength and tough ionic gel is carried out by pre-stretching the gel by 0% to 500%, fixing it to an acrylic plate with clips, and then immersing it in an ionic liquid. The ionic liquid is an amino acid salt ionic liquid, an imidazole salt ionic liquid, a pyridine salt ionic liquid, or a phospholipid salt ionic liquid.

2. A method for preparing the ionogel as described in claim 1, characterized in that, The method includes the following steps: a) Mix polyvinyl alcohol and ethylene glycol at 70-160 degrees Celsius for 1-6 hours to obtain a homogeneous solution; b) Pour the mixed solution obtained in step a) into a mold and freeze it at -80 to -20 degrees Celsius for 1 to 72 hours to obtain an organic ionic gel; c) The organic ionic gel from step b) is placed in 1-400 ml of ionic liquid for fixation-salting-out to obtain a high-strength and tough ionic gel, wherein the volume ratio of the ionic liquid to the organic gel is 1-40:1.

Images