Preparation method of flexible impact-resistant material
By modifying ultra-high molecular weight polyethylene fibers and multi-walled carbon nanotubes, flexible impact-resistant materials are prepared, which solves the problems of weak interface bonding and low energy absorption efficiency, achieves improved flexibility and impact resistance, and is suitable for a variety of application scenarios.
Patent Information
- Application Number
- CN202510880260.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-27
- Publication Date
- 2025-09-16
AI Technical Summary
Existing impact-resistant materials have problems such as weak interface bonding, low energy absorption efficiency, and insufficient flexibility under extreme dynamic impact, especially the poor bonding between ultra-high molecular weight polyethylene fibers and the matrix, and the synergistic mechanism of carbon nanotubes in shear thickening fluids has not been effectively solved.
By modifying the surface of ultra-high molecular weight polyethylene fibers and multi-walled carbon nanotubes, combined with multi-stage modification and functional coupling technology, modified shear thickening fluid and fiber composite materials are prepared to form a three-dimensional energy dissipation network, thereby enhancing the interface bonding strength and stress transfer efficiency.
The flexibility and impact resistance of the material are significantly improved, forming a gradient property combining soft and hard. It can quickly solidify and consume energy at high strain rates, maintain good flexibility and durability, and is suitable for a variety of application scenarios.
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Figure CN120649301A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of intelligent protective materials, and in particular to a method for preparing a flexible impact-resistant material. Background Art
[0002] Flexible impact-resistant materials play a vital role in many fields, including modern industry, transportation, sports protection, and aerospace. Their performance is directly related to the safety and reliability of equipment and the health and safety of personnel. However, traditional impact-resistant materials (such as single shear thickening fluids, fiber composites, or polymer foams) often face the following performance bottlenecks under extreme dynamic impact: the fluidity of shear thickening fluids leads to poor long-term stability; single fiber materials have weak interfacial bonding and low energy absorption efficiency; and rigid materials, while impact-resistant, lack flexibility, limiting their application scenarios.
[0003] In recent years, nano-enhancement and multi-scale structural design have become research hotspots. However, in existing technologies, although ultra-high molecular weight polyethylene (UHMWPE) fibers have high strength, their surface inertness leads to poor bonding with the matrix; although carbon nanotubes can enhance the interface, their uniform loading and synergistic mechanism with shear thickening fluids have not been effectively solved.
[0004] Therefore, there is an urgent need to develop a new type of composite material that is soft, highly impact-resistant and stable through multi-stage modification and functional coupling technology. Summary of the Invention
[0005] The purpose of the present invention is to provide a method for preparing a flexible impact-resistant material to solve the problems in the background technology.
[0006] To achieve the above object, the present invention provides a method for preparing a flexible impact-resistant material, comprising the following steps:
[0007] S1. Preparing a modified shear thickening fluid: adding silica nanoparticles to polyethylene glycol 200-600 under stirring, and mixing well to obtain a shear thickening fluid;
[0008] S2, soaking the ultra-high molecular weight polyethylene fiber fabric in ethanol, performing ultrasonic washing and drying, and then modifying the surface of the dried product to obtain modified U-CA-S fiber;
[0009] S3, soaking the U-CA-S fiber in an aqueous solution of multi-walled carbon nanotubes for 20 to 24 hours, and drying to obtain a modified U-CA-S-MWCNT fiber with multi-walled carbon nanotubes grown on the surface;
[0010] S4. Immerse the modified U-CA-S-MWCNT fiber in the shear thickening liquid obtained in S1, perform ultrasonic oscillation, and place the fiber in a drying oven for drying after the oscillation is completed to obtain a flexible impact-resistant material.
[0011] Preferably, in S1, the mass of the silicon dioxide nanoparticles accounts for 10-14% of the total mass of polyethylene glycol 200-600 and the silicon dioxide nanoparticles.
[0012] Preferably, in S1, the mass of the silicon dioxide nanoparticles accounts for 12% of the total mass of polyethylene glycol 200-600 and the silicon dioxide nanoparticles.
[0013] Preferably, in S1, the particle size of the silicon dioxide particles is 10 to 14 nm.
[0014] Preferably, in S2, the ultrasonic washing time is 50 to 70 minutes, and the modification treatment is carried out by sequentially using catechol and silane coupling agent KH550;
[0015] The process of using catechol for modification is as follows: Tris and catechol are added to distilled water, the pH is adjusted to 8.5 to obtain a mixed solution, dried ultra-high molecular weight polyethylene fiber fabric is placed in the mixed solution, shaken at room temperature, washed and dried to obtain U-CA fiber;
[0016] The modification process using silane coupling agent KH550 is as follows: prepare a KH550 aqueous solution, ultrasonically treat the solution, place the U-CA fiber in the KH550 aqueous solution, stir and react for a certain period of time, then take it out, wash it with distilled water and dry it, ultrasonically clean it again, and dry it to obtain U-CA-S fiber.
[0017] Preferably, the concentrations of catechol and silane coupling agent KH550 are 6.67 g / L and 2 wt %, respectively.
[0018] Preferably, in S3, the mass fraction of the multi-walled carbon nanotubes in the aqueous solution of the multi-walled carbon nanotubes is 0.01 to 0.1%.
[0019] Preferably, in S3, the mass fraction of the multi-walled carbon nanotubes in the aqueous solution of the multi-walled carbon nanotubes is 0.05%.
[0020] Preferably, in S4, the ultrasonic oscillation time is 30 to 45 minutes, the oscillation frequency is 80 to 120 Hz, the drying temperature is 40 to 80° C., and the drying time is 50 to 80 minutes.
[0021] Therefore, the present invention provides a method for preparing a flexible impact-resistant material. Through fiber surface modification and multi-walled carbon nanotube (MWCNT) loading, the interfacial bonding force between UHMWPE fiber and shear thickening fluid is significantly improved, forming a three-dimensional energy dissipation network and enhancing the stress transfer efficiency under dynamic impact. Secondly, the modified shear thickening fluid rapidly solidifies and consumes energy at high strain rates, while the fiber-MWCNT composite structure provides continuous support. The two work together to achieve a gradient impact resistance property of "soft and hard combination".
[0022] The flexible impact-resistant material prepared by the present invention combines the energy absorption characteristics of the shear thickening liquid with the advantages of the high strength and good interfacial compatibility of the modified fiber. During the preparation process, multi-walled carbon nanotubes are loaded so that their growth on the fiber surface can form a three-dimensional network structure, which not only enhances the strength and stiffness of the fiber itself, but also further improves the subsequent compatibility of the fiber with the shear thickening liquid. Ultrasonic oscillation is then used to allow the shear thickening liquid to fully penetrate into the pores and surface structure of the fiber, forming a uniform composite system. After drying, the shear thickening liquid is firmly attached to the fiber surface, forming a protective layer with good impact resistance. This allows the material to effectively absorb and disperse impact energy through the synergistic effect of the shear thickening liquid and the fiber network when it is impacted, while maintaining good flexibility and durability. It has the advantages of a simple preparation process, low cost, and excellent impact resistance, and is suitable for a variety of fields that require flexible impact-resistant materials.
[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Schematic diagram of contact angles of Example 1 of the present invention, wherein (a) is original UHMWPE fiber (UN fiber), (b) is U-CA fiber, (c) is U-CA-S fiber, and (d) is U-CA-S-MWCNT fiber;
[0025] Figure 2 The load-displacement curves and energy-time comparison diagrams of Examples 1-3 of the present invention and Comparative Example 1 under different impact energies are shown, wherein (a) is the load-displacement curve under 8.82 J impact energy, (b) is the energy-time curve under 8.82 J impact energy, (c) is the load-displacement curve under 13.23 J impact energy, (d) is the energy-time curve under 13.23 J impact energy, (e) is the load-displacement curve under 18 J impact energy, and (f) is the energy-time curve under 18 J impact energy. DETAILED DESCRIPTION
[0026] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.
[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.
[0028] Example 1
[0029] This embodiment prepares a flexible impact-resistant material, and the specific steps are as follows:
[0030] S1. Prepare a shear thickening fluid: wherein the mass of the silica nanoparticles accounts for 12% of the total mass of polyethylene glycol 200-600 and the silica nanoparticles, specifically:
[0031] 10 g of polyethylene glycol 200 was added dropwise to a three-necked flask, followed by mechanical stirring at low speed for 30 minutes, and then 1.36 g of silicon dioxide was added in small portions and mechanical stirring was continued for about 10 hours to prepare a shear thickening liquid;
[0032] S2. Soak the ultra-high molecular weight polyethylene fiber fabric (UHMWPE fiber) in ethanol, perform ultrasonic washing, and dry it; then weigh 0.1815 g of Tris and 1 g of catechol and put them into 150 mL of distilled water, adjust the pH to 8.5 with 0.1 mol / L HCl standard solution, place the fiber in the above solution, shake it at room temperature for 38 hours, take it out, rinse it with distilled water several times, and place it in a 60°C oven to dry to obtain catechol-modified UHMWPE fiber (i.e., U-CA fiber).
[0033] Then, a KH550 aqueous solution with a mass fraction of 2% was prepared and ultrasonicated for 30 minutes. Then, the U-CA fiber was placed in the solution, stirred and reacted for a certain period of time, taken out, washed with distilled water, and placed in a 110°C oven for 1 hour. After that, it was taken out and ultrasonically washed again with distilled water for 30 minutes, and placed in a 60°C oven to obtain silane-secondarily modified UHMWPE fiber and U-CA-S fiber.
[0034] S3. Prepare a 0.01% by mass aqueous solution of multi-walled carbon nanotubes, soak the U-CA-S fibers in the solution for 24 hours, and then dry the fibers to obtain U-CA-S-MWCNT fibers with multi-walled carbon nanotubes grown on the surface.
[0035] S4. Immerse the U-CA-S-MWCNT fiber in the shear thickening liquid obtained in S1, ultrasonically oscillate at a frequency of 100 Hz for 30 minutes, and then take it out and place it in a drying oven at 50°C for 1 hour to obtain a flexible impact-resistant material.
[0036] The contact angle test was performed on the products of each step in Example 1. The results are as follows: Figure 1 As shown in the figure, by comparison, it can be seen that the modification with catechol and KH550 reduces the hydrophobicity of the surface of UHMWPE fiber. After the multi-walled carbon nanotubes grow on the surface, the multi-walled carbon nanotube thin layer on the surface has more oxygen-containing functional groups, which can make the shear thickening liquid infiltrate the surface of UHMWPE fiber well.
[0037] Example 2
[0038] The steps of this embodiment are the same as those of embodiment 1, except that the mass fraction of the multi-walled carbon nanotubes is 0.05%.
[0039] Example 3
[0040] The steps of this embodiment are the same as those of embodiment 1, except that the mass fraction of the multi-walled carbon nanotubes is 0.1%.
[0041] Comparative Example 1
[0042] An ultra-high molecular weight polyethylene fiber fabric was used as a comparative example.
[0043] The blunt impact resistance test of the UN fabrics of Examples 1-3 and Comparative Example 1 was conducted. Figure 2 As shown in the figure, the peak load increases with the increase of MWCNT content at a lower impact energy of 8.82 J. When the impact energy is 13.23 J, the peak load of all fabrics is significantly improved compared with the impact energy of 8.82 J.
[0044] Comparing the load-displacement curves of different fabrics, when none of the fabrics were penetrated, the peak load no longer increased monotonically with the MWCNT content, but instead showed a trend of first increasing and then decreasing with increasing MWCNT content. Furthermore, the peak load of the U-CA1-S-MWCNT 0.1% fabric was lower than that of the UN fabric. When the impact energy was further increased to 18 J, the maximum loads of the U-CA1-S-MWCNT 0.01% (Example 1) and U-CA1-S-MWCNT 0.05% (Example 2) fabrics increased further, reaching 2409 N and 2244.5 N, respectively, with a small energy rebound. However, the fabrics of Comparative Example 1 and U-CA1-S-MWCNT 0.1% (Example 3) were penetrated by the impactor, absorbing only 12.9 J and 8.1 J of energy, respectively.
[0045] Therefore, the present invention provides a method for preparing a flexible impact-resistant material. Through reasonable fabric surface treatment, the shear thickening liquid is fully compounded with the fabric, thereby improving the durability and flexibility of the impact-resistant material; the ultra-high molecular weight polyethylene fiber is surface-modified to form a coating, making the surface rough, thereby improving the surface activity and the physical and chemical bonding and adsorption capacity of the high-performance fiber and the shear thickening liquid, thereby achieving the purpose of preparing a high-performance impact-resistant material that is soft, durable and suitable for various environments such as daily protective clothing for military and police, armored weapons, civilian and industrial protection.
[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing a flexible impact-resistant material, characterized in that: The following steps are involved: S1. Preparing a modified shear thickening fluid: adding silica nanoparticles to polyethylene glycol 200-600 under stirring, and mixing well to obtain a shear thickening fluid; S2, soaking the ultra-high molecular weight polyethylene fiber fabric in ethanol, performing ultrasonic washing and drying, and then modifying the surface of the dried product to obtain modified U-CA-S fiber; S3, soaking the U-CA-S fiber in an aqueous solution of multi-walled carbon nanotubes for 20 to 24 hours, and drying to obtain a modified U-CA-S-MWCNT fiber with multi-walled carbon nanotubes grown on the surface; S4. Immerse the modified U-CA-S-MWCNT fiber in the shear thickening liquid obtained in S1, perform ultrasonic oscillation, and place the fiber in a drying oven for drying after the oscillation is completed to obtain a flexible impact-resistant material.
2. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the above-mentioned S1, the mass of the silicon dioxide nanoparticles accounts for 10-14% of the total mass of the polyethylene glycol 200-600 and the silicon dioxide nanoparticles.
3. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the above-mentioned S1, the mass of the silicon dioxide nanoparticles accounts for 12% of the total mass of the polyethylene glycol 200-600 and the silicon dioxide nanoparticles.
4. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the above-mentioned S1, the particle size of the silicon dioxide particles is 10 to 14 nm.
5. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the above-mentioned S2, the ultrasonic washing time is 50 to 70 minutes, and the modification treatment is carried out by sequentially using catechol and silane coupling agent KH550.
6. The method for preparing a flexible impact-resistant material according to claim 5, wherein: The concentrations of catechol and silane coupling agent KH550 are 6.67 g / L and 2 wt %, respectively.
7. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the above S3, the mass fraction of the multi-walled carbon nanotubes in the aqueous solution of the multi-walled carbon nanotubes is 0.01-0.1%.
8. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the above S3, the mass fraction of the multi-walled carbon nanotubes in the aqueous solution of the multi-walled carbon nanotubes is 0.05%.
9. The method for preparing a flexible impact-resistant material according to claim 1, wherein: In the step S4, the ultrasonic oscillation time is 30 to 45 minutes, the oscillation frequency is 80 to 120 Hz, the drying temperature is 40 to 80° C., and the drying time is 50 to 80 minutes.