Preparation method of high-dissipation anti-fatigue elastomer with low-frequency damping characteristic

Abstract

The invention discloses a preparation method of a high-dissipation anti-fatigue elastomer with a low-frequency damping characteristic. The high-dissipation anti-fatigue elastomer with the low-frequency damping characteristic, which has better mechanical property and can effectively filter low-frequency noise, is obtained by introducing polyvinylpyrrolidone, silicon dioxide nanoparticles and two monomers of acrylic acid and acrylic acid-2-methoxyethyl ester and uniformly mixing to carry out simple free radical copolymerization reaction. The elastomer can collect high-quality signals for a long time, and no mechanical fatigue risk exists. In an anti-fatigue test, the tearing capacity of the elastomer can reach 45008.93 J / m < 2 >, and the elastomer is not easy to damage. Under a low-frequency (25, 50 Hz) signal, the material thickness is the same, and the elastomer shows a remarkable audio filtering effect compared with metal, polyurethane, PMMA and sponge. The elastomer can prevent the influence caused by external stimulation (impact, friction and bending) in the use process, and target products with different shapes can be prepared according to different required scenes. The method is suitable for flexible electronic wearing and other fields.

Description

Technical Field

[0001] The invention relates to the field of functional elastomers, in particular to an elastomer with high dissipation, fatigue resistance and low-frequency damping characteristics. Background Art

[0002] Despite its advantages over electronic and information technology solutions, damper noise reduction in microsensors remains a challenge. Complex preparation techniques leading to high production costs and instability of mechanical properties during long-term use due to environmental influences are obstacles to this new technology route.

[0003] Most elastomers have excellent mechanical properties, but they often cannot avoid the rapid expansion of cracks caused by the breakage of covalent bonds in the cross-linked network when stress is concentrated, resulting in the inability to be used multiple times and the inability to effectively dissipate energy, which seriously affects the service life and safety. In addition, the realization of these strategies generally requires a complex synthesis process, and some elastomers are accompanied by the use of chemical cross-linking, which has great limitations in some fields that require simple processing, environmental friendliness, low cost and high efficiency.

[0004] A large number of studies have found that particle filling is a very simple and mature improvement method. Polymer systems reinforced with rigid particles show many properties, such as high strength, high modulus, fatigue resistance and dissipation. However, the phenomenon of loss frequency shifting to low frequency caused by particle aggregation has been ignored. The loss frequency of the polymer system can be transferred to low frequency through particle clustering, and the low-frequency loss helps to absorb the mechanical vibration of the corresponding frequency, thereby achieving signal filtering and noise reduction.

[0005] In the field of smart electronic wearables, elastomers not only need to have excellent damping properties, but also need to be able to respond to external stimuli. During use, it is difficult to avoid collisions, falls, friction, bending and other conditions. Elastomers are required to have excellent mechanical properties and anti-fatigue properties to ensure the stability and durability of the equipment during long-term use, while ensuring the safety of wearing. Taking the above into consideration, the present invention designs an elastomer with a simple preparation process, good mechanical properties, high dissipation and anti-fatigue, and low-frequency damping characteristics. Summary of the invention

[0006] The present invention provides a method for preparing an elastomer with high dissipation, fatigue resistance and low-frequency damping characteristics with a simple process. In view of the problem of insufficient durability of existing dampers, polyvinyl pyrrolidone and silicon dioxide nanoparticles are introduced to improve the rigidity of the elastomer and the interaction within the system, thereby greatly improving the dissipation and fatigue resistance of the elastomer. The elastomer prepared by free radical copolymerization of a uniformly mixed precursor solution has high-strength mechanical properties, transparency, hydrophobicity, impact resistance and low-frequency damping, can absorb mechanical vibrations of corresponding frequencies, and achieve filtering and noise reduction of bioelectronic signals.

[0007] 1. In order to achieve the above object, the present invention provides a method for preparing a high dissipation, anti-fatigue and low-frequency damping elastomer, the preparation method comprising the following steps:

[0008] Step S1: mixing acrylic acid, 2-methoxyethyl acrylate, polyvinyl pyrrolidone, monodisperse silica nanoparticles and a photoinitiator by ultrasonic stirring at room temperature for later use; the polyvinyl pyrrolidone is a wide molecular weight powder solid;

[0009] Step S2: pouring the uniformly mixed solution into a mold, and using ultraviolet light to initiate a free radical polymerization reaction at room temperature to obtain a target product, a high dissipation, fatigue-resistant, and low-frequency damping elastomer;

[0010] Step S3: The obtained gel is placed in deionized water and allowed to stand, and then placed in a 45° C. vacuum oven for drying and set aside.

[0011] It is further defined that the photoinitiator in step S1 includes 1173 initiator, the molar ratio of acrylic acid to 2-methoxyethyl acrylate in step S1 is 3:7, acrylic acid, 2-methoxyethyl acrylate, polyvinyl pyrrolidone, monodisperse silica nanoparticles

[0012] The volume ratio of particles and photoinitiator is 1:4:1.5-1.6:360:0.07-0.08.

[0013] It is further defined that in step S1, the ultrasonic time is at least 10 minutes and the stirring time is at least 3 hours.

[0014] It is further defined that the ultraviolet light initiation time in step S2 is at least 20 minutes, and the polymerization system is completely under nitrogen protection. Use of elastomer: Elastomer can effectively filter low-frequency noise to a certain extent, has excellent anti-fatigue properties, is not easy to damage, and small impacts and bends during use have no significant effect on the elastomer. High-quality signals can be collected for a long time without mechanical fatigue risk.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The high dissipation anti-fatigue and low-frequency damping elastomer prepared by the present invention has strong mechanical properties. The presence of polyvinyl pyrrolidone and silicon dioxide in the system greatly improves the anti-fatigue ability of the gel, thereby further improving the stability and durability of the elastomer.

[0017] 2. The preparation process of the present invention is simple. Only three monomers and inorganic nanoparticles are used for ultraviolet light-induced free radical polymerization, and no solvent or cross-linking agent is required during the polymerization process. The obtained elastomer is easy to transport and store.

[0018] 3. The elastomer prepared by the present invention has low-frequency damping performance, can absorb the corresponding low-frequency mechanical vibration stably for a long time, and realize the filtering and noise reduction of bioelectronic signals without fatigue risk.

[0019] 4. The elastomer prepared by the present invention has excellent durability and stability. During use, if it encounters external impacts such as collision, falling or slight scratches, it will not have a significant impact on its performance, and it can be reused many times. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a Fourier infrared spectrum diagram of Example A1 of the present invention;

[0021] Figure 2 is the C1s spectrum of the high-resolution X-ray photoelectron spectroscopy of Example A1 of the present invention;

[0022] Figure 3 This is a scanning electron microscope image and an energy spectrum diagram of Example A1 of the present invention;

[0023] Figure 4 is a small-angle X-ray scattering diagram of Example A1 of the present invention;

[0024] Figure 5 is the dissipated energy of Example A1 of the present invention when compressed to 10%, 20%, 30%, and 40% of its thickness respectively;

[0025] Figure 6 is the tearing energy of Example A1 of the present invention;

[0026] Figure 7 is an amplitude-time waveform diagram of Example A1 of the present invention compared with polyurethane, sponge, aluminum sheet and PMMA under 25 Hz mechanical vibration;

[0027] Figure 8 It is an amplitude-time waveform diagram of Example A1 of the present invention compared with polyurethane, sponge, aluminum sheet and PMMA under the application of 50 Hz mechanical vibration. DETAILED DESCRIPTION

[0028] The following examples further illustrate the content of the present invention, but should not be construed as limiting the scope of protection of the present invention. Technologies based on non-essential adjustments of the present invention all fall within the scope of the present invention.

[0029] Example 1

[0030] Step S1: 475 μl of acrylic acid, 2 ml of 2-methoxyethyl acrylate, 754 mg of polyvinyl pyrrolidone, 376 mg of silica, and 36 μl of 1173 initiator were ultrasonicated for 10 min, stirred for 3 h, and mixed for later use;

[0031] Step S2: pouring the uniformly mixed solution into a mold of 10 mm×5 mm×1 mm, and using ultraviolet light to initiate the mixture for 20 minutes to obtain the target product, the high dissipation, fatigue-resistant and low-frequency damping elastomer A1;

[0032] Step S3: The prepared elastomer A1 is placed in deionized water and allowed to stand for 24 hours, then placed in a 45° C. vacuum oven for drying, and stored in a dry place.

[0033] Performance Testing:

[0034] Use an infrared spectrometer to scan the target product A1 with a thickness of 1 mm. Figure 1 As shown, A1 was measured at 1651~1659cm -1 The carbonyl peak at the position shifts, forming hydrogen bonds to enhance mechanical properties. The target product A1 with a thickness of 1 mm was scanned using an X-ray photoelectron spectrometer. Figure 2 The peak positions of each group were measured as shown. The target product A1 with a thickness of 1 mm was frozen in liquid nitrogen and then quenched. The cross section was photographed using a scanning electron microscope, and the silicon particle distribution map was obtained using an energy dispersive spectrometer. Figure 3 As shown, it is observed that the silicon particles are uniformly dispersed in the target product A1. A 2D small-angle X-ray scattering diagram of the target product A1 is obtained by a small-angle X-ray scattering instrument. Figure 4 As shown in the figure, a circular scattering ring appears, indicating that there are nanostructures in the target product A1. The target product A1 with a height of 6 mm and a diameter of 15 mm is placed between the upper and lower compression devices, ensuring that there is no gap between the device and the target product, and a single cycle compression test is performed using a universal testing machine. The target product is compressed to 10%, 20%, 30% and 40% of the original height respectively, and the compression rate is 3 mm / min. Figure 5 As shown in Figure 2, the energy dissipated when A1 is compressed to 10%, 20%, 30% and 40% of itself is 19.98 kJ / m 3 、103.62kJ / m 3 、319.15kJ / m 3 、754.71kJ / m 3 On the target product A1 sample of 20mm×15mm×1mm, a notch with a length of 10mm was cut parallel to the long side. The notched A1 sample and the unnotched A1 sample were subjected to tensile tests using a universal testing machine at a tensile rate of 100mm / min. Figure 6 As shown, the tearing energy of A1 is measured to be 45008.93 J / m 2 . Place 1mm thick elastomer A1, polyurethane sheet, sponge sheet, aluminum sheet, and methyl methacrylate sheet between the signal receiving end and the mechanical vibration output end in sequence, and output 25Hz and 50Hz signal vibrations respectively. Then perform a signal capture test and output an amplitude-time graph. Figure 7 , 8 As shown, the elastomer A1 has a significant effect in absorbing low-frequency mechanical vibrations, and basically achieves signal filtering and noise reduction.

Claims

1. A method for preparing a high dissipation, fatigue-resistant and low-frequency damping elastomer, characterized in that: The specific preparation method is as follows: Step S1: mixing acrylic acid, 2-methoxyethyl acrylate, polyvinyl pyrrolidone, monodisperse silica nanoparticles and a photoinitiator by ultrasonic stirring at room temperature for later use; the polyvinyl pyrrolidone is a wide molecular weight powder solid; Step S2: pouring the uniformly mixed solution into a mold, and using ultraviolet light to initiate a free radical polymerization reaction at room temperature to obtain a target product, a high dissipation, fatigue-resistant, and low-frequency damping elastomer; Step S3: The obtained elastomer is placed in deionized water and allowed to stand, and then placed in a 45° C. vacuum oven for drying and set aside.

2. The method for preparing a high dissipation anti-fatigue elastic body with low-frequency damping characteristics according to claim 1, characterized in that: The photoinitiator in step S1 is 1173 initiator, the molar ratio of acrylic acid and 2-methoxyethyl acrylate in step S1 is 3:7, and the volume ratio of acrylic acid, 2-methoxyethyl acrylate, polyvinyl pyrrolidone, monodisperse silica nanoparticles and photoinitiator is 1:4:1.5-1.6:360:0.07-0.

08.

3. The method for preparing a high dissipation, anti-fatigue and low-frequency damping elastic body according to claim 1, characterized in that: The diameter of the monodispersed silica nanoparticles in step S1 is 1 micron.

4. The method for preparing a high dissipation, anti-fatigue and low-frequency damping elastic body according to claim 1, characterized in that: In step S1, the ultrasonication time is at least 10 min, and the stirring time is at least 3 h.

5. The method for preparing a high dissipation, anti-fatigue and low-frequency damping elastic body according to claim 1, characterized in that: In step S2, the ultraviolet light initiation time is at least 20 minutes, and the polymerization system is completely under nitrogen protection.

6. Application of a high dissipation, anti-fatigue and low-frequency damping elastic body according to any one of claims 1 to 5, characterized in that: Elastomers can effectively filter low-frequency noise to a certain extent, have excellent anti-fatigue properties, and are not easy to damage. Small impacts and bending during use have no significant effect on the elastomers. High-quality signals can be collected for a long time without the risk of mechanical fatigue.

7. The use of a high dissipation, anti-fatigue and low-frequency damping elastic body according to claim 6, characterized in that: The thickness of the elastomer is 1 mm.

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