Itaconyl hydrazide-induced Janus structure polymer epidermal patch electrode and preparation method thereof

Abstract

The present invention discloses an itaconyl hydrazide-induced Janus structure polymer, which is a polymer prepared by gradient polymerization under ultraviolet light using itaconyl hydrazide and vinyl monomer as main raw materials. The present invention also discloses an itaconyl hydrazide-induced Janus structure polymer epidermal patch electrode, which is an epidermal patch electrode obtained by connecting the polymer to the electrode and integrating it into a signal processing module. The itaconyl hydrazide-induced Janus structure of the present invention and the hydrogen bond network formed thereby give the polymer excellent stretchability, flexibility, and homogeneous conformal properties, which can ensure the high signal-to-noise ratio, high stability and reliability of the polymer epidermal patch electrode for electrocardiogram signal monitoring. The polymer epidermal patch electrode of the present invention can be used for electrocardiogram signal monitoring in different environments, different motion states, and when worn for a long time, and is particularly applicable to the application of epidermal patch electrodes in wearable health monitoring.

Description

Technical Field

[0001] The present invention relates to an itaconyl hydrazide-induced, integrally molded Janus-structured polymer, a preparation method thereof, and an epidermal patch electrode based on the Janus-structured polymer. The epidermal patch electrode, which forms a Janus structure through gradient polymerization induced by the solubility differences of itaconyl hydrazide in vinyl monomers, combines the advantages of high stretchability, high homogeneity and conformality, high signal-to-noise ratio, and signal stability. It can be applied to monitor electrocardiogram signals in different environments and different motion states, and particularly relates to the application of epidermal patch electrodes in wearable health monitoring. Background Art

[0002] Epidermal patch electrodes are wearable technology devices with significant application potential, playing a vital role in areas such as human-computer interaction interfaces, wearable medicine, and physiological monitoring. Because they come into direct contact with human skin and can be conveniently integrated with electronic transmission, storage, and processing components on multifunctional devices, they accurately identify and transmit a variety of physiological data. However, complex external conditions place stringent demands on the portability, stability, and response accuracy of epidermal patch electrodes. Accurately and dynamically monitoring the human body's physiological state in different external environments and under varying motion conditions remains a significant challenge.

[0003] In recent years, polymer epidermal patch electrodes have shown broad application prospects in the field of epidermal patch electrodes due to their advantages of strong adhesion to the skin and the lack of problems such as hydrogel water loss and solvent leakage. However, the polymer epidermal patch electrodes currently on the market still have certain performance barriers, such as the elastic strain within the physiological motion range being lower than the biological tissue deformation range (50%), poor homogeneity and conformality, etc., which make it impossible for polymer epidermal patch electrodes to monitor for a long time, and the signal-to-noise ratio of the collected signals in interference environments (such as motion state, wet interface, etc.) is low, which seriously limits their practical application. Janus-structured conductive polymers are an ion-conducting polymer network formed by the polymerization of two different functional vinyl monomers with various conductive salts. By tailoring the structural and functional differences on both sides, the interfacial conformality and mechanical properties of the polymer can be significantly improved. Therefore, constructing high-performance Janus-structured conductive polymers during the polymerization process is an effective solution for preparing simple, high-performance epidermal patch electrodes. Summary of the Invention

[0004] The present invention aims to address the common shortcomings of current polymer epidermal patch electrodes, such as low elastic strain, poor conformality, low response signal-to-noise ratio, and poor stability. By providing a low-cost itaconyl hydrazide-induced, one-piece Janus-structured polymer prepared by UV photopolymerization, and constructing an epidermal electrode patch based on this Janus-structured polymer, the present invention addresses the common shortcomings of current polymer epidermal patch electrodes, such as low elastic strain, poor conformality, low response signal-to-noise ratio, and poor stability. This Janus-structured polymer epidermal electrode patch exhibits advantages such as high stretchability, flexibility, high conformality, and a high signal-to-noise ratio, effectively expanding the practical application performance of polymer epidermal patch electrodes.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] The invention discloses an itaconyl hydrazide-induced Janus structure polymer, which is prepared by ultraviolet light polymerization using itaconyl hydrazide and vinyl monomer as main raw materials.

[0007] The itaconyl hydrazide-induced Janus structure polymer is prepared by the following method: dissolving itaconic acid and an activator in an organic solvent under stirring, heating to 30-50° C., then dropwise adding hydrazine hydrate, heating to 60-80° C. and reacting for 6-8 hours to obtain itaconyl hydrazide; mixing itaconyl hydrazide with two vinyl monomers under stirring, and stirring at room temperature until a red transparent homogeneous solution is formed; dissolving a lithium salt and an initiator in the homogeneous solution, and ultrasonically dispersing the solution to obtain a precursor solution; blowing nitrogen into the precursor solution to remove oxygen, pouring the precursor solution into a polytetrafluoroethylene mold, and allowing it to stand; irradiating the mold with ultraviolet light, and allowing it to stand at room temperature to obtain a polymer.

[0008] Another object of the present invention is to provide a method for preparing an itaconyl hydrazide-induced Janus structure polymer, comprising the following steps:

[0009] Step (1), dissolving itaconic acid and an activator in an organic solvent under stirring, heating to 30-50° C., adding hydrazine hydrate dropwise, heating to 60-80° C., and reacting for 6-8 hours to obtain itaconic acid hydrazide;

[0010] Step (2), mixing itaconyl hydrazide with two vinyl monomers under stirring, and stirring at room temperature until a red transparent homogeneous solution is formed;

[0011] Step (3), dissolving the lithium salt and the initiator in a homogeneous solution, and ultrasonically dispersing to obtain a precursor solution;

[0012] Step (4), nitrogen is bubbled into the precursor solution to remove oxygen, and the precursor solution is poured into a polytetrafluoroethylene mold and allowed to stand;

[0013] Step (5): irradiating the mold with ultraviolet light and allowing it to stand at room temperature to obtain a Janus structure polymer.

[0014] In step (1), the organic solvent is one of dichloromethane, dimethyl sulfoxide, and N,N-dimethylformamide; the activator is one of dicyclohexylcarbodiimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide; the mass ratio of itaconic acid to the activator is 1:2 to 1:3; and the mass ratio of itaconic acid to hydrazine hydrate is 1:2 to 1:3.

[0015] The stirring speed is 300-800 rpm.

[0016] In step (2), the mass ratio of itaconyl hydrazide to vinyl monomer is 1:10 to 1:40; the two vinyl monomers are respectively two of acrylate monomers or crotonate monomers substituted with a hydroxyl group and a trimethylammonium group; the acrylate monomers substituted with a hydroxyl group and a trimethylammonium group are methyl acrylate, ethyl acrylate, isopropyl acrylate, and butyl acrylate; the crotonate monomers substituted with a hydroxyl group and a trimethylammonium group are methyl crotonate, ethyl crotonate, isopropyl crotonate, and butyl crotonate; the mass ratio of the two vinyl monomers is 3:1 to 1:3.

[0017] The stirring speed is 300-800 rpm.

[0018] In step (3), the mass ratio of the lithium salt to the vinyl monomer is 1:50 to 1:100; the mass ratio of the lithium salt to the vinyl monomer is preferably 1:60 to 1:100; the mass ratio of the lithium salt to the vinyl monomer is most preferably 1:80 to 1:100;

[0019] The molar ratio of the initiator to the vinyl monomer is 1:50 to 1:450;

[0020] The lithium salt is one of lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium chloride, lithium bromide and lithium iodide.

[0021] The initiator is one of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone and 2,4,6 (trimethylbenzoyl) diphenylphosphine oxide.

[0022] The power of the ultrasound is 100W, and it works for 3 seconds with an interval of 1 second.

[0023] The ultrasonic dispersion time is 30 minutes.

[0024] In step (4), the method for removing oxygen from the precursor solution is: nitrogen is blown into the precursor solution for 10 minutes to remove oxygen from the precursor solution, and the standing time is 1 to 5 minutes.

[0025] In step (5), the wavelength of the ultraviolet light is 365nm to 405nm; the power of the ultraviolet light is 40W to 80W; the irradiation time is 10 seconds to 1 minute, and the standing time is 0.5 to 2 hours.

[0026] Another object of the present invention is to provide an epidermal electrode patch based on a Janus structure polymer induced by itaconyl hydrazide, which is an epidermal patch electrode obtained by connecting the Janus structure polymer described in the present invention to an electrode and integrating it into a signal processing module.

[0027] The epidermal patch electrode of the present invention is low-cost, has a simple preparation process, and exhibits advantages such as high stretchability, flexibility, high conformality, and a high signal-to-noise ratio. Therefore, the epidermal patch electrode of the present invention can be used to monitor ECG signals in various environments, during various exercise states, and during prolonged wear.

[0028] Beneficial effects of the present invention:

[0029] The present invention addresses the common shortcomings of current polymer epidermal patch electrodes, such as low elastic strain, poor conformality, low response signal-to-noise ratio, and poor stability, and prepares a polymer with a Janus structure through ultraviolet light-induced free radical polymerization. The difference in solubility of itaconyl hydrazide in different vinyl monomers induces gradient polymerization of monomers to form a Janus structure, which gives the polymer different adhesion properties on both sides. The nitrogen cations accumulated at one end have tenacious adhesion to the epidermis, while the weak hydroxyl group at the other end is shielded by itself and the hydrazide group, showing weaker adhesion properties. In addition, the hydrogen bond network formed by itaconyl hydrazide in the polymer has dynamic and flexible non-covalent cross-linking, which significantly improves the mechanical properties and conformality of the polymer. In addition, the dynamic hydrogen bond network can provide a monitoring environment for signal acquisition that is not easily affected by external factors, ensuring that it can collect stable physiological signals with a high signal-to-noise ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The stress-strain curves of polymers prepared with different itaconyl hydrazide dosages.

[0031] Figure 2 This is the stretching-recovery cycle curve of the polymer prepared in Example 1.

[0032] Figure 3 Adhesion performance test of the polymer prepared in Example 1.

[0033] Figure 4 Adhesion cycle test of the polymer prepared in Example 1.

[0034] Figure 5 Adhesion performance test of each part of the polymer prepared in Example 1.

[0035] Figure 6 This is the sensitivity factor of the polymer epidermal patch electrode prepared in Example 1 to stretching.

[0036] Figure 7 This is the skin surface impedance of the polymer epidermal patch electrode prepared in Example 1.

[0037] Figure 8 Monitoring of electrocardiographic signals using the polymer epidermal patch electrode prepared in Example 1.

[0038] Figure 9 The polymer epidermal patch electrode prepared in Example 1 monitors the electrocardiogram signal in a swinging state.

[0039] Figure 10 The polymer epidermal patch electrode prepared in Example 1 monitors electrocardiographic signals in a wet state.

[0040] Figure 11 Long-term monitoring of electrocardiographic signals using the polymer epidermal patch electrode prepared in Example 1. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be further described below in conjunction with specific implementation methods.

[0042] Example 1

[0043] Step (1), dissolving 3 g of itaconic acid and 9 g of dicyclohexylcarbodiimide in dichloromethane under stirring, heating to 50° C., adding 6 g of hydrazine hydrate dropwise, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0044] Step (2): Slowly mix 0.25 g of itaconyl hydrazide with 5 g of 2-hydroxyethyl acrylate and 5 g of acryloyloxyethyl trimethylammonium chloride under stirring at 300 rpm, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 2.5% of the mass of the vinyl monomer.

[0045] Step (3): 0.1 g of lithium bis(trifluoromethanesulfonyl)imide and 0.1 mL of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone were dissolved in the homogeneous solution and ultrasonically dispersed for 30 minutes at an ultrasonic power of 100 W, with a 3-second interval and a 1-second interval, to obtain a precursor solution. The mass of lithium bis(trifluoromethanesulfonyl)imide was 1% of the mass of the vinyl monomer, and the molar mass of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone was 0.02% of the molar mass of the vinyl monomer.

[0046] Step (4), nitrogen was bubbled into the precursor solution for 10 minutes to remove oxygen from the precursor solution, and the precursor solution was poured into a polytetrafluoroethylene mold and allowed to stand for 1 minute;

[0047] Step (5): irradiate the mold with 40W, 365nm ultraviolet light for 1 minute, and then let it stand at room temperature for 30 minutes to obtain a polymer.

[0048] Figure 1 : The stress-strain curves of polymers prepared with different itaconyl hydrazide dosages, wherein the stress-strain curve of the polymer prepared in this example corresponds to 2.5% (ie, the mass of itaconyl hydrazide is 2.5% of the mass of the vinyl monomer).

[0049] Figure 2 This is the polymer's 50% stress-tension-release cycle curve. This indicates that the polymer can maintain stable mechanical properties over 1,000 load-release cycles, demonstrating good stability and durability.

[0050] Figure 3 The polymer was shown to have high adhesion strength compared to other commercial tapes (plastic tape, paper tape, 3M silicone tape, and 3M paper tape).

[0051] Figure 4 The adhesion strength of the polymer is measured when repeated adhesion is performed 10 times under three adhesion tests (lap shear test, peel test, and tensile test), showing stable adhesion performance.

[0052] Figure 5 The adhesion strength of each part of the polymer to the commercial electrode shows strong adhesion performance and self-differential adhesion compared to commercial electrodes.

[0053] Figure 6 The sensitivity factor of the polymer epidermal patch electrode is approximately 0.15, with a linear relationship between the resistance change rate and the stretch rate within a 1000% stretch range. This excellent sensitivity stability ensures interference resistance during ECG signal monitoring.

[0054] Figure 7 The skin surface impedance of the polymer epidermal patch electrode and the commercial skin patch electrode. The smaller skin surface impedance enables the polymer epidermal patch electrode to monitor more reliable and stronger ECG signals.

[0055] Figure 8 a and Figure 8 b shows the monitoring of ECG signals by polymer epidermal patch electrodes and commercial epidermal patch electrodes, respectively. The ECG signals monitored by the polymer epidermal patch electrodes show a higher signal-to-noise ratio.

[0056] Figure 9 a and Figure 9b shows the monitoring of ECG signals by the polymer epidermal patch electrode in the wrist bending state and the resting state, respectively. The similar signal-to-noise ratio indicates that the polymer epidermal patch electrode has good monitoring stability in the deformed state.

[0057] Figure 10 a and Figure 10 b shows the monitoring of ECG signals by the polymer epidermal patch electrode in wet and dry states, respectively. The similar signal-to-noise ratios indicate that the polymer epidermal patch electrode has good monitoring stability in the simulated sweating state.

[0058] Figure 11 The long-term monitoring of ECG signals by polymer epidermal patch electrodes and commercial patch electrodes shows that in ECG signal monitoring, polymer epidermal patch electrodes have stronger and more stable monitoring performance than commercial patch electrodes.

[0059] Example 2

[0060] Step (1), dissolving 3 g of itaconic acid and 9 g of dicyclohexylcarbodiimide in dichloromethane under stirring, heating to 50° C., adding 6 g of hydrazine hydrate dropwise, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0061] Step (2): Control the rotation speed to 300 rpm and slowly mix 0.5 g of itaconyl hydrazide with 5 g of 2-hydroxyethyl acrylate and 5 g of acryloyloxyethyl trimethylammonium chloride under stirring, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 5% of the mass of the vinyl monomer.

[0062] The polymer was prepared according to steps (3) to (5) of Example 1.

[0063] The stress-strain curve of the polymer prepared in this example is shown in Figure 1 .

[0064] Example 3

[0065] Step (1), dissolving 3 g of itaconic acid and 9 g of dicyclohexylcarbodiimide in dichloromethane under stirring, heating to 50° C., adding 6 g of hydrazine hydrate dropwise, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0066] Step (2): Slowly mix 0.75 g of itaconyl hydrazide with 5 g of 2-hydroxyethyl acrylate and 5 g of acryloyloxyethyl trimethylammonium chloride under stirring at 300 rpm, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 7.5% of the mass of the vinyl monomer.

[0067] The polymer was prepared according to steps (3) to (5) of Example 1.

[0068] The stress-strain curve of the polymer prepared in this example is shown in Figure 1 .

[0069] Example 4

[0070] Step (1), dissolving 3 g of itaconic acid and 9 g of dicyclohexylcarbodiimide in dichloromethane under stirring, heating to 50° C., adding 6 g of hydrazine hydrate dropwise, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0071] Step (2): Slowly mix 1 g of itaconyl hydrazide with 5 g of 2-hydroxyethyl acrylate and 5 g of acryloyloxyethyl trimethylammonium chloride under stirring at 300 rpm, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 10% of the mass of the vinyl monomer.

[0072] The polymer was prepared according to steps (3) to (5) of Example 1.

[0073] The stress-strain curve of the polymer prepared in this example is shown in Figure 1 .

[0074] Example 5

[0075] Step (1), dissolving 3 g of itaconic acid and 9 g of dicyclohexylcarbodiimide in dichloromethane under stirring, heating to 50° C., adding 6 g of hydrazine hydrate dropwise, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0076] Step (2): Control the rotation speed to 300 rpm and slowly mix 5 g of 2-hydroxyethyl acrylate and 5 g of acryloyloxyethyl trimethylammonium chloride under stirring, and stir at room temperature until a red transparent homogeneous solution is formed, wherein the mass of itaconyl hydrazide is 0% of the mass of the vinyl monomer.

[0077] The polymer was prepared according to steps (3) to (5) of Example 1.

[0078] The stress-strain curve of the polymer prepared in this example is shown in Figure 1 .

[0079] Depend on Figure 1 It can be seen that different contents of itaconyl hydrazide have a huge impact on the mechanical properties of the polymer. When the mass ratio of itaconyl hydrazide to vinyl monomer is 0:10 to 1:10, the elongation of the polymer increases and the tensile strength decreases, showing excellent elongation and tensile strength as well as adjustable mechanical properties; especially when the mass of itaconyl hydrazide is 5% of the mass of vinyl monomer, the balance of elongation and toughness of the polymer reaches the optimal level.

[0080] Example 6

[0081] Step (1), dissolving 3 g of itaconic acid and 6 g of dicyclohexylcarbodiimide in dichloromethane under stirring, heating to 50° C., adding dropwise 6 g of hydrazine hydrate, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0082] Step (2): Slowly mix 0.25 g of itaconyl hydrazide with 5 g of 2-hydroxypropyl acrylate and 5 g of acryloyloxypropyltrimethylammonium chloride under stirring at 300 rpm, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 2.5% of the mass of the vinyl monomer.

[0083] Step (3): 0.1 g of lithium bis(trifluoromethanesulfonyl)imide and 0.1 mL of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone were dissolved in the homogeneous solution and ultrasonically dispersed for 30 minutes at an ultrasonic power of 100 W, with a 3-second interval and a 1-second interval, to obtain a precursor solution. The mass of lithium bis(trifluoromethanesulfonyl)imide was 1% of the mass of the vinyl monomer, and the molar mass of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone was 0.02% of the molar mass of the vinyl monomer.

[0084] Step (4), nitrogen was bubbled into the precursor solution for 10 minutes to remove oxygen from the precursor solution, and the precursor solution was poured into a polytetrafluoroethylene mold and allowed to stand for 1 minute;

[0085] Step (5): irradiate the mold with 40W, 365nm ultraviolet light for 1 minute and let it stand at room temperature for 30 minutes to obtain a polymer.

[0086] The inventors examined the performance of the polymer and polymer epidermal patch electrode prepared in this embodiment with reference to Example 1, and both achieved the same performance as in Example 1.

[0087] Example 7

[0088] Step (1), dissolving 3 g of itaconic acid and 6 g of dicyclohexylcarbodiimide in dimethyl sulfoxide under stirring, heating to 50° C., adding dropwise 9 g of hydrazine hydrate, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0089] Step (2): Control the rotation speed to 300 rpm and slowly mix 0.25 g of itaconyl hydrazide with 5 g of 2-hydroxybutyl acrylate and 5 g of crotonyloxybutyltrimethylammonium chloride under stirring, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 2.5% of the mass of the vinyl monomer.

[0090] Step (3): 0.1 g of lithium hexafluorophosphate and 0.1 mL of 2-hydroxy-2-methyl-1-phenyl-1-propanone were dissolved in the homogeneous solution and ultrasonically dispersed for 30 minutes at an ultrasonic power of 100 W, with a 3-second interval and a 1-second interval, to obtain a precursor solution, wherein the mass of lithium hexafluorophosphate is 1% of the mass of the vinyl monomer, and the molar mass of 2-hydroxy-2-methyl-1-phenyl-1-propanone is 0.02% of the molar mass of the vinyl monomer.

[0091] Step (4), nitrogen was bubbled into the precursor solution for 10 minutes to remove oxygen from the precursor solution, and the precursor solution was poured into a polytetrafluoroethylene mold and allowed to stand for 1 minute;

[0092] Step (5): irradiate the mold with 40W, 365nm ultraviolet light for 1 minute and let it stand at room temperature for 1.5 hours to obtain a polymer.

[0093] The inventors examined the performance of the polymer and polymer epidermal patch electrode prepared in this embodiment with reference to Example 1, and both achieved the same performance as in Example 1.

[0094] Example 8

[0095] Step (1), dissolving 3 g of itaconic acid and 9 g of dicyclohexylcarbodiimide in N,N-dimethylformamide under stirring, heating to 50° C., adding 6 g of hydrazine hydrate dropwise, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0096] Step (2): Slowly mix 0.25 g of itaconyl hydrazide with 5 g of 2-hydroxypropyl crotonic acid and 5 g of acryloyloxybutyltrimethylammonium chloride under stirring at 300 rpm, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 2.5% of the mass of the vinyl monomer.

[0097] Step (3): 0.1 g of lithium tetrafluoroborate and 0.1 mL of 2,4,6-trimethylbenzoyldiphenylphosphine oxide were dissolved in a homogeneous solution and ultrasonically dispersed for 30 minutes at an ultrasonic power of 100 W, with a 1-second interval between each 3-second operation, to obtain a precursor solution. The mass of lithium tetrafluoroborate was 1% of the mass of the vinyl monomer, and the molar mass of 2,4,6-trimethylbenzoyldiphenylphosphine oxide was 0.02% of the molar mass of the vinyl monomer.

[0098] Step (4), nitrogen was bubbled into the precursor solution for 10 minutes to remove oxygen from the precursor solution, and the precursor solution was poured into a polytetrafluoroethylene mold and allowed to stand for 3 minutes;

[0099] Step (5): irradiate the mold with 40W, 365nm ultraviolet light for 1 minute and let it stand at room temperature for 1 hour to obtain a polymer.

[0100] The inventors examined the performance of the polymer and polymer epidermal patch electrode prepared in this embodiment with reference to Example 1, and both achieved the same performance as in Example 1.

[0101] Example 9

[0102] Step (1), dissolving 3 g of itaconic acid and 9 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide in dichloromethane under stirring, heating to 50° C., adding dropwise 6 g of hydrazine hydrate, and heating to 80° C. for 8 hours to obtain itaconic acid hydrazide;

[0103] Step (2): Slowly mix 0.25 g of itaconyl hydrazide with 5 g of 2-hydroxyethyl crotonate and 5 g of crotonyloxyethyl trimethylammonium chloride under stirring at 300 rpm, and stir at room temperature until a red, transparent, homogeneous solution is formed. The mass of itaconyl hydrazide is 2.5% of the mass of the vinyl monomer.

[0104] Step (3): 0.1 g of lithium bis(trifluoromethanesulfonyl)imide and 0.1 mL of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone were dissolved in the homogeneous solution and ultrasonically dispersed for 30 minutes at an ultrasonic power of 100 W, with a 3-second interval and a 1-second interval, to obtain a precursor solution. The mass of lithium bis(trifluoromethanesulfonyl)imide was 1% of the mass of the vinyl monomer, and the molar mass of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone was 0.02% of the molar mass of the vinyl monomer.

[0105] Step (4), nitrogen was bubbled into the precursor solution for 10 minutes to remove oxygen from the precursor solution, and the precursor solution was poured into a polytetrafluoroethylene mold and allowed to stand for 5 minutes;

[0106] Step (5): irradiate the mold with 40W, 365nm ultraviolet light for 1 minute, and then let it stand at room temperature for 2 hours to obtain a polymer.

Claims

1. An itaconyl hydrazide-induced Janus structure polymer, characterized in that: It is prepared by the following method: Under stirring, itaconic acid and an activator are dissolved in an organic solvent, heated to 30-50°C, and then hydrazine hydrate is added dropwise, and heated to 60-80°C for reaction for 6-8 hours to obtain itaconic hydrazide; the activator is one of dicyclohexylcarbodiimide and 1-ethyl-(3-dimethylaminopropyl)carbodiimide, and the mass ratio of itaconic acid to the activator is 1:2-1:3; the mass ratio of itaconic acid to hydrazine hydrate is 1:2-1:3; under stirring, itaconic hydrazide is mixed with two vinyl monomers, and stirred at room temperature until a red transparent homogeneous solution is formed; the two vinyl monomers are added to form a mixture of the activator and the hydrazine hydrate. The vinyl monomers are selected from one of a hydroxyl-substituted acrylate monomer or a hydroxyl-substituted crotonate monomer and one of a trimethylammonium-substituted acrylate monomer or a trimethylammonium-substituted crotonate monomer; the mass ratio of itaconyl hydrazide to the vinyl monomer is 1:10 to 1:40, and the mass ratio of the two vinyl monomers is 3:1 to 1:3; a lithium salt and an initiator are then dissolved in a homogeneous solution and ultrasonically dispersed to obtain a precursor solution; nitrogen gas is bubbled into the precursor solution to remove oxygen, and the precursor solution is poured into a polytetrafluoroethylene mold and allowed to stand. The mold was irradiated with ultraviolet light and allowed to stand at room temperature to obtain a polymer.

2. The itaconyl hydrazide-induced Janus structure polymer according to claim 1, characterized in that: The acrylic acid ester monomers are methyl acrylate, ethyl acrylate, isopropyl acrylate and butyl acrylate; the crotonic acid ester monomers are methyl crotonic acid, ethyl crotonic acid, isopropyl crotonic acid and butyl crotonic acid.

3. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 1, characterized in that: The following steps are involved: Step (1), dissolving itaconic acid and an activator in an organic solvent under stirring, heating to 30-50°C, adding hydrazine hydrate dropwise, heating to 60-80°C, and reacting for 6-8 hours to obtain itaconic hydrazide; Step (2), mixing itaconyl hydrazide with two vinyl monomers under stirring, and stirring at room temperature until a red transparent homogeneous solution is formed; Step (3), dissolving the lithium salt and the initiator in a homogeneous solution, and ultrasonically dispersing to obtain a precursor solution; Step (4), nitrogen is bubbled into the precursor solution to remove oxygen, and the precursor solution is poured into a polytetrafluoroethylene mold and allowed to stand; Step (5): irradiate the mold with ultraviolet light and let it stand at room temperature to obtain a Janus structure polymer.

4. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 3, characterized in that: In step (1), the organic solvent is one of dichloromethane, dimethyl sulfoxide, and N,N-dimethylformamide.

5. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 3, characterized in that: In step (3), the mass ratio of the lithium salt to the vinyl monomer is 1:50 to 1:100; the molar ratio of the initiator to the vinyl monomer is 1:50 to 1:450; the lithium salt is one of lithium bis(trifluoromethanesulfonyl)imide, lithium hexafluorophosphate, lithium tetrafluoroborate, lithium chloride, lithium bromide, and lithium iodide; the initiator is one of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 2,4,6(trimethylbenzoyl)diphenylphosphine oxide; The ultrasonic power is 100 W, and the operation lasts for 3 seconds with an interval of 1 second.

6. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 5, characterized in that: In step (3), the mass ratio of the lithium salt to the vinyl monomer is 1:50 to 1:

80.

7. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 6, characterized in that: In step (3), the mass ratio of the lithium salt to the vinyl monomer is 1:50 to 1:

60.

8. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 3, characterized in that: In step (4), the method for removing oxygen from the precursor solution is: blowing nitrogen into the precursor solution to remove oxygen from the precursor solution; the standing time is 1 to 5 minutes.

9. The method for preparing an itaconyl hydrazide-induced Janus structure polymer according to claim 3, characterized in that: In step (5), the wavelength of the ultraviolet light is 365 nm to 405 nm; the power of the ultraviolet light is 40 W to 80 W; the irradiation time is 10 seconds to 1 minute; and the standing time is 0.5 to 2 hours.

10. An epidermal patch electrode of an itaconyl hydrazide-induced Janus structure polymer, characterized in that: It is an epidermal patch electrode obtained by connecting the polymer described in claim 1 to an electrode and integrating it into a signal processing module.

11. The epidermal patch electrode of the itaconyl hydrazide-induced Janus structure polymer according to claim 10 is used for monitoring electrocardiogram signals in different environments, different exercise states, and when worn for a long time.

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