Preparation method of high-dissipation fatigue-resistant elastic body with low-frequency damping characteristics

Abstract

The application discloses a preparation method of a high-dissipation fatigue-resistant elastic body with low-frequency damping characteristics. By introducing polyvinylpyrrolidone and silica nanoparticles, and uniformly mixing two monomers of acrylic acid and 2-methoxyethyl acrylate, a simple free radical copolymerization reaction is carried out to obtain a high-dissipation fatigue-resistant elastic body with good mechanical properties and effective filtering of low-frequency noise. The elastic body can collect high-quality signals for a long time without mechanical fatigue risk. In the fatigue resistance test, the tear energy of the elastic body can reach 45008.93 J / m 2 , and it is not easy to be damaged itself. Under low-frequency (25, 50 Hz) signals, the elastic body shows a significant audio filtering effect compared with metal, polyurethane, PMMA and sponge with the same material thickness. The elastic body can prevent the influence of external stimuli (impact, friction and bending) during use, and different target products with different shapes can be prepared according to different required scenes. It is suitable for flexible electronic wearable fields.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of functional elastomers, in particular, to a high-dissipation anti-fatigue elastomer with low-frequency damping characteristics. BACKGROUND

[0002] Despite the advantages compared to electronic and information technology solutions, the damper noise reduction solution in microsensors is still a challenge. The complex preparation techniques lead to high production costs, the instability of mechanical properties over time due to environmental influences, which are obstacles to this new technological approach.

[0003] Most elastomers have excellent mechanical properties, but often cannot avoid the rapid crack propagation caused by the rupture of covalent bonds in the crosslinked network when stress concentration occurs, resulting in problems such as inability to be used multiple times and inability to effectively dissipate energy, which seriously affect the service life and safety. Moreover, the implementation of these strategies generally involves complex synthesis processes, and some elastomers are accompanied by the use of chemical crosslinking, 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 exhibit many characteristics, such as high strength, high modulus, fatigue resistance, and dissipation. However, the phenomenon of loss frequency shift to low frequency caused by particle aggregation has been overlooked. The loss frequency of the polymer system can be shifted to low frequency by particle clustering, and low-frequency loss helps to absorb mechanical vibrations of the corresponding frequency, thereby achieving signal filtering and noise reduction.

[0005] In the field of intelligent electronic wearables, elastomers not only need to have excellent damping characteristics, but also need to be able to respond to external stimuli. In the use process, it is difficult to avoid some collisions, falls, rubs, bends, and other conditions, and the elastomer needs to have excellent mechanical properties and fatigue resistance to ensure the stability and durability of the device during long-term use, while ensuring the safety of wearing. In view of the above, the present application designs an elastomer with simple preparation process, good mechanical properties, high dissipation, anti-fatigue, and low-frequency damping characteristics. SUMMARY

[0006] The present application provides a preparation method of a high-dissipation anti-fatigue elastomer with low-frequency damping characteristics, which has a simple process. In view of the problem of insufficient durability of existing dampers, the rigidity of the elastomer and the interaction within the system are improved by introducing polyvinylpyrrolidone and silicon dioxide nanoparticles, thereby greatly improving the dissipation and fatigue resistance of the elastomer. The elastomer prepared by free radical copolymerization of the uniformly mixed precursor solution has high mechanical properties, transparency, hydrophobicity, impact resistance, and low-frequency damping properties, can absorb mechanical vibrations of the corresponding frequency, and achieve biological electronic signal filtering and noise reduction.

[0007] 1. In order to achieve the above object, the present application provides a preparation method of a high-dissipation anti-fatigue elastic body with low-frequency damping characteristics, comprising the following steps:

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

[0009] Step S2: pouring the uniformly mixed solution into a mold and performing free radical polymerization reaction under the initiation of ultraviolet light at room temperature to obtain a target product of a high-dissipation anti-fatigue elastic body with low-frequency damping characteristics;

[0010] Step S3: placing the obtained gel into deionized water for standing, and then transferring it into a vacuum oven at 45°C for drying, for standby.

[0011] Further limitation, the photoinitiator in step S1 includes 1173 initiator, the molar ratio of acrylic acid and 2-methoxyethyl acrylate in step S1 is 3:7, the volume ratio of acrylic acid, 2-methoxyethyl acrylate, polyvinylpyrrolidone, monodisperse silica nanoparticles and photoinitiator in step S1 is 1:4:1.5-1.6:360:0.07-0.08.

[0012] Further limitation, the ultrasonic time in step S1 is at least 10 min, and the stirring time is at least 3 h.

[0013] Further limitation, the ultrasonic time in step S1 is at least 10 min, and the stirring time is at least 3 h.

[0014] Further limitation, the ultraviolet light initiation time in step S2 is at least 20 min, and the polymerization system is completely protected by nitrogen. The elastic body can effectively filter low-frequency noise to a certain extent, has excellent anti-fatigue characteristics, is not easy to damage, has no significant effect on the elastic body during the use process of small amplitude impact and bending, can collect high-quality signals for a long time, and has no mechanical fatigue risk.

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

[0016] 1. The high-dissipation anti-fatigue elastic body with low-frequency damping characteristics prepared by the present application has strong mechanical properties, and the presence of polyvinylpyrrolidone and silica in the system greatly improves the anti-fatigue ability of the gel, thereby further improving the stability and durability of the elastic body.

[0017] 2. The preparation process of the present application is simple. Only three kinds of monomers and inorganic nanoparticles are used for ultraviolet light-induced free radical polymerization, and no solvent or crosslinking agent is needed during the polymerization process. The obtained elastic body is easy to transport and store.

[0018] 3. The elastomer prepared by the present application has low-frequency damping performance, can stably absorb mechanical vibration of corresponding low frequency for a long time, realizes filtering and noise reduction of bioelectronic signals, and has no fatigue risk.

[0019] 4. The elastomer prepared by the present application has excellent durability and stability. In the use process, if external impact such as collision, falling or slight scratch is encountered, the performance will not be significantly affected, and repeated use can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the Fourier infrared spectrum of the embodiment A1 of the present application;

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

[0022] Figure 3 is the scanning electron microscope image and energy spectrum of the embodiment A1 of the present application;

[0023] Figure 4 is the small-angle X-ray scattering diagram of the embodiment A1 of the present application;

[0024] Figure 5 is the dissipation energy of the embodiment A1 of the present application when compressed to 10%, 20%, 30%, and 40% of its own thickness, respectively;

[0025] Figure 6 is the tearing energy of the embodiment A1 of the present application;

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

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

[0028] The following examples further illustrate the content of the present application, but should not be understood as limiting the scope of protection of the present application. The technology based on non-essential adjustment of the present application belongs to the scope of the present application.

[0029] Example 1

[0030] Step S1: ultrasonic 10min, 3h stirring, 475ul acrylic acid, 2ml acrylic acid-2-methoxyethyl ester, 754mg polyvinylpyrrolidone, 376mg silicon dioxide, 36ul 1173 initiator, mixing and ready for use;

[0031] Step S2: Pour the well-mixed solution into a 10mm×5mm×1mm mold, and after initiating with ultraviolet light for 20 minutes, the target product, high dissipation, fatigue-resistant elastomer A1 with low-frequency damping characteristics, can be obtained.

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

[0033] Performance testing:

[0034] The target product A1, with a thickness of 1 mm, was scanned using an infrared spectrometer. For example... Figure 1 As shown, A1 was measured to be between 1651 and 1659 cm. -1 The carbonyl peak shifts, forming hydrogen bonds that enhance mechanical properties. X-ray photoelectron spectroscopy was used to scan the target product A1, which is 1 mm thick. Figure 2 As shown, the peak positions of each functional group were measured. The target product A1, with a thickness of 1 mm, was quenched after being frozen in liquid nitrogen. The cross-section was photographed using a scanning electron microscope, and the silicon particle distribution was obtained using energy dispersive spectroscopy. Figure 3 As shown, silicon particles were observed to be uniformly dispersed within the target product A1. A 2D small-angle X-ray scattering pattern was obtained from the target product A1 using a small-angle X-ray scattering instrument. Figure 4 As shown in the figure, a circular scattering ring appears, indicating the presence of nanostructures in the target product A1. The target product A1, with a height of 6 mm and a diameter of 15 mm, was placed between the upper and lower compression devices, ensuring no gap between the devices and the target product. A single-cycle compression test was performed using a universal testing machine. The target product was compressed to 10%, 20%, 30%, and 40% of its original height, respectively, at a compression rate of 3 mm / min. Figure 5 As shown, the energy dissipated when A1 is compressed to 10%, 20%, 30%, and 40% of its own weight is 19.98 kJ / m³. 3 103.62 kJ / m 3 319.15 kJ / m 3 754.71 kJ / m 3 A 10mm notch was cut parallel to the long side of the 20mm × 15mm × 1mm target product A1 specimen. Tensile tests were performed on the notched A1 specimen and the unnotched A1 specimen using a universal testing machine at a tensile rate of 100mm / min. Figure 6 As shown, the tear energy of A1 was measured to be 45008.93 J / m. 2 A 1mm thick elastomer A1, a polyurethane sheet, a sponge sheet, an aluminum sheet, and a methyl methacrylate sheet were sequentially placed between the signal receiving end and the mechanical vibration output end. Signal vibrations of 25Hz and 50Hz were output respectively, followed by signal capture testing, and the amplitude-time graph was output. (See attached image.)Figure 7 , 8 As shown in FIG. 9, the elastomer A1 has a significant effect on absorbing low-frequency mechanical vibration, and basically realizes signal filtering and noise reduction.

Claims

1. A method of making a high-dissipating fatigue-resistant, low-frequency-damping elastomer, characterized by: The specific preparation method is as follows: Step S1: ultrasonic 10 min for 475 μl of acrylic acid, 2 ml of 2-methoxyethyl acrylate, 754 mg of polyvinylpyrrolidone, 376 mg of silica, 36 μl of 1173 initiator, and stir for 3 h to mix evenly for standby; Step S2: the mixed solution is poured into a mold, and a free radical polymerization reaction is carried out at room temperature using ultraviolet light initiation to obtain the target product high-dissipation anti-fatigue low-frequency damping characteristic elastomer; Step S3: the obtained elastomer is placed in deionized water and then transferred into a 45℃ vacuum oven for drying, ready for use.

2. The method of claim 1, wherein the method further comprises: The monodisperse silica nanoparticles in step S1 have a diameter of 1 micron. ​ 3. The method of claim 1, wherein the method further comprises: The ultrasonic time in step S1 is at least 10 min, and the stirring time is at least 3 h. ​ 4. The method of claim 1, wherein the method further comprises: The ultraviolet light initiation time in step S2 is at least 20 min, and the polymerization system is completely protected by nitrogen.

5. The preparation method of a high-dissipation anti-fatigue low-frequency damping characteristic elastomer according to claim 1, wherein the thickness of the elastomer prepared by the method is 1 mm.

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