KR-20260067526-A - Hydrogel with water resistance and manufacturing method thereof

Abstract

The present invention relates to a hydrogel, specifically to a hydrogel having both an ion-conducting portion based on an acrylic polymer and an electrically conductive portion of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). Additionally, the present invention relates to a hydrogel to which PEG or PEGME is added to increase the water resistance (or durability) of the hydrogel.

Inventors

• 김재찬
• 이선종
• 김동민
• 주예원

Assignees

• 주식회사 바이오프로테크

Dates

Publication Date

20260513

Application Date

20241106

Claims (10)

1. Acrylic polymer; PEDOT:PSS; and A hydrogel comprising one or more additives selected from PEG and PEGME.
2. In claim 1, based on 100 parts by weight of an acrylic polymer in the hydrogel, A hydrogel comprising 1 to 100 parts by weight of PEDOT:PSS and 1 to 30 parts by weight of additives.
3. In claim 1, the hydrogel, wherein the molecular weight of the additive is 500 to 20,000.
4. In claim 1, the above acrylic polymer is a hydrogel that is a homopolymer of a first monomer having an acrylic group, or a copolymer of a first monomer having an acrylic group and a second monomer having a different functional group.
5. In Paragraph 4, The first monomer having the above acrylic group is acrylic acid, and A hydrogel in which the second monomer is 2-acrylamido-2-methylpropane sulfonic acid.
6. Preparation step (1) of a first solution comprising a monomer comprising a first monomer comprising an acrylic group, a crosslinking agent, a photoinitiator, an electrolyte, and deionized water Preparation step (2) of a second solution of PEDOT:PSS and an alcohol solvent; Step (3) for preparing a mixed solution of the first solution and the second solution; An additive mixing step (4) of mixing one or more of PEG and PEGME as additives into the above mixed solution; and A method for manufacturing a hydrogel comprising the step (5) of crosslinking by irradiating a mixed solution containing the above additives with ultraviolet light.
7. A method for preparing a hydrogel according to claim 6, wherein the mixed solution is mixed with 1 to 100 parts by weight of PEDOT:PSS and 1 to 30 parts by weight of the additive, based on 100 parts by weight of the monomer.
8. A method for preparing a hydrogel according to claim 6, wherein the molecular weight of the additive is 500 to 20,000.
9. A method for preparing a hydrogel according to claim 6, wherein the monomer is a mixed monomer of a first monomer having an acrylic group and a second monomer having a functional group other than an acrylic group.
10. In paragraph 9, the first monomer having the acrylic group is acrylic acid, and A method for preparing a hydrogel in which the second monomer is 2-acrylamido-2-methylpropane sulfonic acid.

Description

Conductive hydrogel with water resistance and manufacturing method thereof The present invention relates to a hydrogel. In particular, the present invention relates to a hydrogel having both an ion-conducting portion based on an acrylic polymer and an electrically conductive portion of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), and in particular, to a hydrogel having excellent water resistance (or durability). Polymer conductive hydrogels are materials generally used for various applications, such as medical electrodes, diapers, contact lenses, and cell cultures. Hydrogels are hydrophilic polymers crosslinked by cohesive forces such as covalent bonds, hydrogen bonds, van der Waals bonds, or physical bonds, and have a network structure capable of swelling by containing a large amount of water in an aqueous solution. The present invention relates to a hydrogel used in medical electrodes. Conventional hydrogel adhesive patches for ECG (electrocardiogram) and EMG (electromyography) sensors have ion conductivity characteristics based on acrylic adhesives. As shown in Fig. 1, volume expansion or reduction of the hydrogel occurs due to penetration or dissolution by moisture, resulting in unstable ion conductivity, which leads to reduced sensing capability and noise generation. Furthermore, conventional hydrogel patches have problems such as detachment during use due to weakened water resistance and durability as usage time increases, making long-term measurement impossible and causing discomfort to the user . Figure 1 is a diagram illustrating the swelling/de-swelling phenomenon caused by moisture in a hydrogel containing a conventional ion-conducting acrylic polymer. Figure 2 is a diagram explaining the difference between a conventional hydrogel and the hydrogel of the present invention. Figure 3 is a photograph of the mixed solution of Comparative Example and Examples 1 to 8. Figure 4 is a photograph of the samples of Comparative Example and Examples 1 to 8 after curing. Figure 5 is a photograph of the water resistance test results of the samples of Comparative Example and Examples 1 to 8 after curing. In the following explanation, "polymer" is used in a comprehensive sense including "copolymer" and is used interchangeably with "polymer." Figure 2 is a diagram illustrating the difference between a conventional hydrogel and the hydrogel of the present invention. The present invention is characterized by adding PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), which has excellent electrical conductivity, in addition to the acrylic polymer, to an ion-conducting-based acrylic polymer hydrogel to improve electrical conductivity properties. In PEDOT:PSS, the ":" signifies hydrogen bonding. As a mixture of PEDOT and PSS that is not a copolymer, PSS and PEDOT compensate for each other's charges, and PEDOT oligomers are strongly bonded to the PSS polymer chains. Depending on the mixing ratio of PEDOT and PSS, the PEDOT:PSS solution can selectively exhibit hydrophilicity or hydrophobicity. In the present invention, PEDOT:PSS, which has excellent electrical conductivity, is used as a component to impart electrical conductivity to the hydrogel. In addition, the present invention is characterized by using an "alcohol" solvent when preparing a mixed solution of PEDOT:PSS. When the solvent of PEDOT:PSS is water-based, the miscibility with an acrylic monomer solution is very unsuitable for hydrogels; however, to improve this, the present invention is characterized by using an alcohol-based PEDOT:PSS to improve the miscibility with an acrylic monomer solution. In addition, the present invention includes PEG (poly(ethylene glycol)) or PEGME (poly(ethylene glycol) methyl ether) as an essential component for improving water resistance or durability. While it is understood that PEG or PEGME improves the water resistance and durability of the entire hydrogel through chemical bonding with PEDOT:PSS, further research is needed regarding the theoretical basis. In the present invention, for every 100 parts by weight of the acrylic polymer, PEDOT:PSS may be used in an amount of 1 to 100 parts by weight and additives in an amount of 1 to 30 parts by weight. In particular, the molecular weight of the above additive may be 500 to 20,000. The above acrylic polymer may be a homopolymer of a first monomer having an acrylic group, or a copolymer of a first monomer having an acrylic group and a second monomer having a different functional group. In particular, the first monomer having an acrylic group may be acrylic acid, and the second monomer may be 2-acrylamido-2-methylpropanesulfonic acid. In addition, the present invention provides a method for manufacturing a hydrogel comprising: a step of preparing a first solution (1) comprising a monomer having an acrylic group as a functional group, a crosslinking agent, a photoinitiator, an electrolyte, and deionized water; a step of preparing a second solutio