Hydrogel with long-term adhesion performance in seawater as well as preparation method and application of hydrogel

Abstract

The invention relates to hydrogel with long-term adhesion performance in seawater as well as a preparation method and application of the hydrogel. The preparation method of the hydrogel comprises the steps of preparing a monomer mixture, preparing a hydrogel precursor solution, preparing the hydrogel and the like. The hydrogel with long-term adhesion performance in seawater has very long-term underwater adhesion capability, and has excellent marine antifouling capability. The hydrogel is simple in preparation process and low in raw material cost, and has large-scale production and application prospects.

Description

[Technical field]

[0001] The present invention belongs to the technical field of polymer hydrogels. More specifically, the present invention relates to a hydrogel having long-term adhesion performance in seawater, a preparation method of the hydrogel, and a use of the hydrogel. [Background technology]

[0002] Hydrogel is a polymer material with a three-dimensional network structure and water as the dispersion medium. There are a large number of hydrophilic groups on its molecular chain, which has excellent water absorption and water retention capabilities. It is soft and elastic. In addition, hydrogel has good antifouling ability due to its hydration layer and low elastic modulus. Therefore, hydrogel has been widely used in various fields in recent years, such as wound dressings, environmental testing, and antifouling of marine equipment.

[0003] The hydration layer of hydrogels can easily lose its adhesion ability because it is in an aqueous environment. In addition, excessive water molecules fill the gaps between polymer chains, which will weaken the interaction between polymer chains, causing the mechanical properties to weaken and even causing the cross-linked structure to collapse. The hydrogel cannot maintain its shape and thus cannot adhere to the surface of the substrate for a long time. At present, research on improving the adhesion performance of hydrogels mainly focuses on the adhesion strength of hydrogels, but the underwater adhesion strength is not the same as the underwater adhesion time. If the hydrogel cannot achieve long-term underwater adhesion, its practical application will be severely limited, and it cannot be guaranteed that the performance of the hydrogel can be exerted for a long time.

[0004] The inventor has finally completed the present invention based on summarizing the prior art through a large amount of experimental research and analysis and summary. [Summary of the invention]

[0005] [Technical issues to be solved]

[0006] The object of the present invention is to provide a hydrogel having long-term adhesion properties in seawater.

[0007] Another object of the present invention is to provide a method for preparing the hydrogel.

[0008] Another object of the present invention is to provide use of the hydrogel in preventing marine fouling.

[0009] [Technical solution]

[0010] The present invention is achieved through the following technical solutions.

[0011] The invention also relates to a method for preparing a hydrogel with long-term adhesion performance in seawater.

[0012] The preparation steps of the preparation method are as follows:

[0013] A. Preparation of Monomer Mixture

[0014] The hydrophobic acrylic monomer, the hydrophilic acrylic monomer and the crosslinking monomer are mixed uniformly in a molar ratio of 30-80:10-60:1-10, and then 0-50% of a mixed organic solvent and 2.0-6.0% of an initiator are added based on the total mass of the monomers, and mixed uniformly to obtain the monomer mixture;

[0015] B. Preparation of hydrogel precursor solution

[0016] In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 100-300% of a mixed organic solvent based on the total mass of the monomer mixture obtained in step A and 5-15% of the monomer mixture are added under nitrogen protection, mixed evenly, then heated to a temperature of 65-95° C., and kept at this temperature for 15-50 minutes, and then the remaining monomer mixture is evenly divided into 4-12 portions, and one portion is added every 15-35 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.15-0.6% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 1-4 hours to obtain the hydrogel precursor solution;

[0017] C. Preparation of hydrogel

[0018] The hydrogel precursor solution prepared in step B is placed in the air, dried at room temperature, and then placed in seawater to obtain the hydrogel having long-term adhesion properties in seawater.

[0019] According to a preferred embodiment of the present invention, in step A, the hydrophobic acrylic monomer is one or more hydrophobic acrylic monomers selected from methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, dodecyl methacrylate, myristyl acrylate, myristyl methacrylate, hexadecyl acrylate, octadecyl acrylate or octadecyl methacrylate.

[0020] According to another preferred embodiment of the present invention, in step A, the hydrophilic acrylic monomer is one or more hydrophilic acrylic monomers selected from acrylic acid, methacrylic acid, itaconic acid, acrylamide, N-hydroxymethyl acrylamide, N-hydroxyethyl acrylamide, N,N-methylenebisacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate or 3-(dimethylamino)propyl acrylate, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methyl 2-(hydroxymethyl)acrylate or ethyl 2-(hydroxymethyl)acrylate.

[0021] According to another preferred embodiment of the present invention, in step A, the crosslinking monomer is one or more crosslinking monomers selected from 3,5,6-tris(N-hydroxymethylacrylamide)-4-(2-aminoethyl)-1,2-benzenediol hydrochloride, N,N',N"-((2,4,6-trihydroxybenzene-1,3,5-triyl)tris(methylene))triacrylamide, N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tris(methylene))triacrylamide or N,N',N"-((6-chloro-3,5-dihydroxybenzene-1,2,4-triyl)tris(methylene))triacrylamide.

[0022] According to another preferred embodiment of the present invention, in step A, the initiator is one or more initiators selected from azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, di(2-ethylhexyl) peroxydicarbonate, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl perbenzoate, potassium persulfate or ammonium persulfate.

[0023] According to another preferred embodiment of the present invention, in step A, the organic solvent is one or more organic solvents selected from xylene, methyl isobutyl ketone, butyl acetate, n-butanol, ethanol or cyclohexanone.

[0024] The invention also relates to a hydrogel prepared by the preparation method and having long-term adhesion performance in seawater.

[0025] According to a preferred embodiment of the present invention, the adhesion property of the hydrogel in seawater is that it will not fall off from the surface of the substrate after being immersed in seawater.

[0026] According to a preferred embodiment of the present invention, the adhesion performance of the hydrogel in seawater is maintained for more than 310 days.

[0027] The invention also relates to the use of the hydrogel in preventing marine pollution.

[0028] The present invention will be described in more detail below.

[0029] The invention relates to a method for preparing a hydrogel capable of achieving long-term underwater adhesion.

[0030] Hydrogel is a polymer material with a three-dimensional network structure using water as a dispersion medium. It has a good antifouling effect due to its hydration layer and low elastic modulus. However, the underwater adhesion of hydrogel has always been a challenge, and it is difficult to maintain the underwater adhesion for a long time. The inventors propose to introduce a cross-linking monomer with three double bonds and a polyphenol structure to promote the long-term stability of the cross-linking structure of the hydrogel on the basis of introducing a hydrophobic structure and a variety of viscosity-enhancing structures such as phenolic hydroxyl groups to improve the adhesion of the hydrogel, so that the network structure of the hydrogel that is underwater for a long time will not collapse, thereby increasing the long-term adhesion time of the hydrogel under seawater.

[0031] The preparation steps of the preparation method are as follows:

[0032] A. Preparation of Monomer Mixture

[0033] The hydrophobic acrylic monomer, the hydrophilic acrylic monomer and the crosslinking monomer are mixed uniformly in a molar ratio of 30-80:10-60:1-10, and then 0-50% of a mixed organic solvent and 2.0-6.0% of an initiator are added based on the total mass of the monomers, and mixed uniformly to obtain the monomer mixture;

[0034] In the present invention, the hydrophobic acrylic monomer should be understood as an acrylic monomer without a hydrophilic group. Its main function in the hydrogel of the present invention is to provide the hydrogel with a large number of viscosity-increasing structures with hydrophobic association to improve the adhesion ability of the hydrogel.

[0035] The hydrophobic acrylic monomer used in the present invention is one or more hydrophobic acrylic acid ester monomers selected from methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, dodecyl methacrylate, tetradecyl acrylate, tetradecyl methacrylate, hexadecyl acrylate, octadecyl acrylate or octadecyl methacrylate, all of which are products currently sold on the market, such as butyl acrylate sold by Tianjin Tianjiao Chemical Co., Ltd. under the trade name of butyl acrylate.

[0036] In the present invention, the hydrophilic acrylic monomer should be understood as an acrylic monomer containing a hydrophilic group, and its main function in the hydrogel of the present invention is that it provides a large number of hydrophilic groups that can combine with water molecules, so that the hydrogel absorbs water to form a hydration layer.

[0037] The hydrophilic acrylic monomer used in the present invention is one or more hydrophilic acrylic monomers selected from acrylic acid, methacrylic acid, itaconic acid, acrylamide, N-hydroxymethyl acrylamide, N-hydroxyethyl acrylamide, N,N-methylenebisacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate or 3-(dimethylamino)propyl acrylate, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methyl 2-(hydroxymethyl)acrylate or ethyl 2-(hydroxymethyl)acrylate, all of which are products currently sold on the market, such as acrylamide sold under the trade name acrylamide by Jiangxi Jiuchang Agricultural Science and Chemical Co., Ltd., and dimethylaminoethyl methacrylate sold under the trade name dimethylaminoethyl methacrylate by Aladdin Reagent Co., Ltd.

[0038] In the present invention, the main role of the cross-linking monomer in preparing the hydrogel of the present invention is to provide a cross-linking structure so that the hydrogel can form a three-dimensional network structure, and also to provide a phenolic hydroxyl viscosity-enhancing structure to promote the adhesion of the hydrogel.

[0039] The crosslinking monomer used in the present invention is one or more crosslinking monomers selected from 3,5,6-tris(N-hydroxymethylacrylamide)-4-(2-aminoethyl)-1,2-benzenediol hydrochloride, N,N',N"-((2,4,6-trihydroxybenzene-1,3,5-triyl)tris(methylene))triacrylamide, N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tris(methylene))triacrylamide or N,N',N"-((6-chloro-3,5-dihydroxybenzene-1,2,4-triyl)tris(methylene))triacrylamide.

[0040] In the present invention, the cross-linking monomer is prepared from the following raw materials:

[0041] 3,5,6-Tris(N-hydroxymethylacrylamide)-4-(2-aminoethyl)-1,2-benzenediol hydrochloride is prepared from 0.36 mol N-hydroxymethylacrylamide and 0.1 mol dopamine hydrochloride:

[0042] N,N',N"-((2,4,6-trihydroxybenzene-1,3,5-triyl)tri(methylene))triacrylamide was prepared from 0.36 mol of N-hydroxymethylacrylamide and 0.1 mol of phloroglucinol;

[0043] N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tri(methylene))triacrylamide was prepared from 0.36 mol of N-hydroxymethylacrylamide and 0.1 mol of o-methylhydroquinone;

[0044] N,N',N"-((6-chloro-3,5-dihydroxybenzene-1,2,4-triyl)tris(methylene))triacrylamide was prepared from 0.36 mol of N-hydroxymethylacrylamide and 0.1 mol of 4-chlororesorcinol.

[0045] Specifically, the preparation method of the cross-linking monomer is as follows:

[0046] Two kinds of raw materials are placed in a 500mL three-necked flask, 120mL of anhydrous ethanol is added, mixed uniformly, 10mL of concentrated sulfuric acid catalyst with a concentration of 98% by mass is added dropwise to the three-necked flask using a constant pressure funnel, 30 minutes after the addition is completed, the three-necked flask is heated to 35°C with an oil bath, reacted at such a temperature for three days, and then separated using a suction filtration device, the filter cake obtained is washed with deionized water until the washing solution is neutral, and the washed solid is dried to obtain the crosslinked monomer. The raw materials N-hydroxymethyl acrylamide, dopamine hydrochloride, phloroglucinol, o-methylhydroquinone and 4-chlororesorcinol used in the present invention are all products currently sold on the market, such as the N-hydroxymethyl acrylamide sold by Linzi Yizhong Forest Chemical Co., Ltd., Zibo City, under the trade name N-hydroxymethyl acrylamide.

[0047] In this step, when the amount of the hydrophilic acrylic monomer and the cross-linking monomer is within the range, if the amount of the hydrophobic acrylic monomer is less than 30, the hydrophobic structure content of the hydrogel will be too small, and the adhesion performance of the hydrogel will be difficult to maintain; if the amount of the hydrophobic acrylic monomer is higher than 80, the hydrophilic structure content of the hydrogel will be too small, which is not conducive to water absorption to form a hydrogel. Therefore, it is reasonable to use 30 to 80 of the hydrophobic acrylic monomer, preferably 35 to 70, and more preferably 40 to 60.

[0048] When the amount of the hydrophobic acrylic monomer and the cross-linking monomer is within the above range, if the amount of the hydrophilic acrylic monomer is less than 10, the hydrophilic structure content of the hydrogel will be too small, and the hydrogel will not have sufficient water absorption capacity; if the amount of the hydrophilic acrylic monomer is higher than 60, the hydrogel will absorb too much water, and the excess water molecules will fill the gaps between the polymer chains, weakening the interaction between the polymer chains, making it difficult for the hydrogel to maintain its shape and easy to fall off from the surface of the substrate. Therefore, the amount of the hydrophilic acrylic monomer is appropriately 10 to 60, preferably 20 to 50, and more preferably 25 to 45.

[0049] When the amount of the hydrophobic acrylic monomer and the hydrophilic acrylic monomer is within the range, if the amount of the cross-linking monomer is less than 1, the number of cross-linked structures in the hydrogel will be insufficient, the hydrogel will be easily destroyed after absorbing water, and the mechanical properties will be too poor, the shape of the hydrogel will be difficult to maintain, and long-term underwater adhesion will not be achieved; if the amount of the cross-linking monomer is higher than 10, gel will appear during the polymerization process, which is not conducive to the smooth progress of the polymerization reaction, and an effective hydrogel cannot be obtained. Therefore, the amount of the cross-linking monomer is suitable to be 1 to 10, preferably 1.5 to 8.0, and more preferably 2.0 to 7.0.

[0050] Preferably, the molar ratio of the hydrophobic acrylic monomer, the hydrophilic acrylic monomer and the crosslinking monomer is 35-70:20-50:1.5-8.0, and more preferably 40-60:25-45:2.0-7.0.

[0051] According to the present invention, the main function of the initiator in the preparation of the hydrogel of the present invention is that the initiator will decompose into free radicals, thereby initiating the polymerization reaction of the monomers to generate polymers.

[0052] The initiator used in the present invention is an initiator selected from azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, di(2-ethylhexyl) peroxydicarbonate, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl perbenzoate, potassium persulfate or ammonium persulfate, all of which are products currently sold on the market, such as the azobisisobutyronitrile sold by Tianjin Damao Chemical Reagent Factory under the trade name azobisisobutyronitrile.

[0053] The same initiator needs to be used in the subsequent steps of preparing the hydrogel of the present invention, so it will not be described in detail below.

[0054] In this step, if the amount of the initiator is higher than 6.0%, the molecular weight of the hydrogel of the present invention will be too low, which is not conducive to improving its mechanical properties, and the molecular weight dispersion coefficient will be too large, which is not conducive to process stability; if the amount of the initiator is lower than 2.0%, the polymerization reaction will be unstable or not initiated, and the molecular weight of the prepolymer will be too large, so the polymerization reaction cannot proceed smoothly. Therefore, it is reasonable to use an initiator of 2.0-6.0%, preferably 2.5-5.0%.

[0055] The organic solvent used in this step is one or more organic solvents selected from xylene, methyl isobutyl ketone, butyl acetate, n-butanol, ethanol or cyclohexanone, all of which are products currently sold on the market, such as the xylene sold by Qingdao Datang Chemical Co., Ltd. under the trade name xylene.

[0056] The mixed organic solvent used in this step should be understood as a solvent formed by mixing two or more organic solvents in any proportion.

[0057] The same mixed organic solvent is also required to be used in the subsequent steps of preparing the hydrogel of the present invention, so it will not be described in detail below.

[0058] In this step, when the amounts of the hydrophobic acrylic monomer, the hydrophilic acrylic monomer and the cross-linking monomer are within the range, the mixed organic solvent may not be used if the cross-linking monomer can be uniformly dispersed in the hydrophobic acrylic monomer and the hydrophilic acrylic monomer, that is, the mixed organic solvent may be 0; if the amount of the mixed organic solvent is higher than 50%, the organic solvent content may be excessive, resulting in a waste of resources; therefore, the amount of the mixed organic solvent is appropriately 0 to 50%, preferably 8 to 40%, and more preferably 12 to 35%.

[0059] B. Preparation of hydrogel precursor solution

[0060] In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 100-300% of a mixed organic solvent based on the total mass of the monomer mixture obtained in step A and 5-15% of the monomer mixture are added under nitrogen protection, mixed evenly, and then heated to a temperature of 65-95° C., and kept at this temperature for 15-50 minutes, and then the remaining monomer mixture is evenly divided into 4-12 parts, and one part is added every 15-35 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.15-0.6% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 1-4 hours to obtain the hydrogel precursor solution.

[0061] In this step, 100-300% of the mixed organic solvent and 5-15% of the monomer mixture are maintained at a temperature of 65° C. to 95° C. for 15-50 minutes.

[0062] When the amount of the monomer mixture is within the range, if the amount of the mixed organic solvent is less than 100%, the viscosity of the prepolymer in the later stage of the reaction will be large, the reaction will be uneven, and it will be unfavorable for later use; if the amount of the mixed organic solvent is higher than 300%, a large amount of volatile organic matter will be volatilized during the later use, polluting the environment and causing waste of resources. Therefore, it is appropriate to use 100 to 300% of the mixed organic solvent, preferably 150 to 250%. When the amount of the mixed organic solvent is within the range, if the amount of the monomer mixture is lower than 5%, the polymerization reaction in the early stage will be insufficient, which is unfavorable for the stable reaction in the later stage; if the amount of the monomer mixture is higher than 15%, the reaction will be violent in the initial stage, and the temperature of the reaction system will be difficult to control, which will bring safety hazards. Therefore, it is appropriate to use 5 to 15% of the monomer mixture, preferably 8 to 12%.

[0063] In this step, when the reaction time is within the range, if the reaction temperature is lower than 65°C, it is not conducive to the decomposition of the initiator and the smooth progress of the polymerization reaction; if the reaction temperature is higher than 95°C, the polymerization reaction will be too violent, there will be potential safety hazards, and the distribution coefficient of the polymer molecular weight will be too large, and the process will be unstable. Therefore, it is appropriate for the reaction temperature to be 65 to 95°C, preferably 70 to 90°C. When the reaction temperature is within the range, if the reaction time (holding time) is shorter than 15 minutes, the initiation reaction is insufficient, which is not conducive to the stable progress of the later reaction; if the reaction time is longer than 50 minutes, it is easy to cause dead-end polymerization and is not conducive to the improvement of process efficiency. Therefore, it is appropriate for the reaction time to be 15 to 50 minutes, preferably 20 to 45 minutes.

[0064] In this step, the remaining monomer mixture is divided into 4 to 12 portions, and one portion is added every 15 to 35 minutes. The main purpose is to avoid adding too much monomer mixture at a single time, which cannot be dispersed into the reaction system in time. It can also avoid too violent reaction, causing the reaction temperature to be too high, causing safety problems and unstable reaction.

[0065] In this step, the purpose of adding initiator after keeping warm for 1 hour is to make the unreacted monomers in the system participate in the reaction and polymerization. The reaction is continued for 1 to 4 hours after adding initiator, and its basic function is to ensure that the unreacted monomers are fully reacted and polymerized.

[0066] The reaction container, electric stirring device, oil bath pot, drying device, etc. used in the present invention are all chemical equipment or devices commonly used in the field of chemical technology.

[0067] The conventional infrared spectroscopy analysis method was used to analyze the hydrogel with long-term adhesion performance in seawater prepared by the present invention. The analysis results are listed in the attached Figure 1 middle.

[0068] The invention relates to a hydrogel prepared by the preparation method and having long-term adhesion performance in seawater.

[0069] According to the present invention, the adhesion property of the hydrogel in seawater should be understood as that it will not fall off from the surface of the substrate after being immersed in seawater.

[0070] According to "Determination of Salt Water Resistance of Marine Coatings - Salt Water and Hot Salt Water Immersion Method" (GB / T10834-2008), the inventors conducted a static bubble board experiment and investigated that the adhesion performance of the hydrogel in seawater was maintained for more than 310 days.

[0071] The present invention also relates to the use of the hydrogel of the present invention in preventing marine fouling. The antifouling performance of the hydrogel in the actual ocean is investigated through a real sea hanging board experiment, and the specific test results are shown in the specific examples.

[0072] [Beneficial Effects]

[0073] The beneficial technical effects of the present invention are:

[0074] The preparation method of the hydrogel with long-term adhesion performance in seawater of the present invention is simple, the raw materials are cheap and easily available, and large-scale production is possible; the hydrogel has excellent marine antifouling ability and very long underwater adhesion ability, and the time is significantly better than the underwater adhesion time of existing hydrogels.

Brief Description of the Drawings

[0075] Attached Figure 1 is an infrared spectrum of the hydrogel with long-term adhesion performance in seawater prepared in Example 1-5;

[0076] Attached Figure 2 is a graph showing the adhesion performance test results of the hydrogels prepared in Examples 1-5 with long-term adhesion performance in seawater;

[0077] Attached Figure 3 This is a picture of the actual sea hanging board result of the hydrogel with long-term adhesion performance in seawater prepared in Examples 1-5; [Specific implementation method]

[0078] The present invention is described in detail below with reference to the embodiments.

[0079] Example 1: Preparation of the hydrogel having long-term adhesion in seawater of the present invention

[0080] The implementation steps of this embodiment are as follows:

[0081] A. Preparation of Monomer Mixture

[0082] The butyl methacrylate hydrophobic acrylic monomer, the acrylic acid and dimethylaminoethyl acrylate hydrophilic acrylic monomer and the N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tri(methylene))triacrylamide crosslinking monomer are mixed uniformly in a molar ratio of 80:(5+5):1, and then 0% of a mixed organic solvent and 2.0% of an azobisisobutyronitrile initiator are added based on the total weight of the monomers, and the mixture is mixed uniformly to obtain the monomer mixture;

[0083] B. Preparation of hydrogels that can achieve long-term underwater adhesion

[0084] In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 100% of a mixed organic solvent of xylene and n-butanol (mass ratio 3:2) based on the total mass of the monomer mixture obtained in step A and 15% of the monomer mixture are added under nitrogen protection, and then the reaction system is heated to a temperature of 65°C; at the same time, this temperature is maintained for 50 minutes, and then the remaining monomer mixture is evenly divided into 4 parts, and one part is added every 35 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.15% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 1 hour to obtain the hydrogel precursor solution;

[0085] C. Preparation of hydrogel

[0086] The hydrogel precursor solution prepared in step B is placed in the air, dried at room temperature, and then placed in seawater to obtain the hydrogel having long-term adhesion properties in seawater.

[0087] The product prepared in this example was analyzed using conventional infrared spectroscopy analysis. The analysis results are shown in the attached Figure 1 From the analysis results, it can be determined that the product is the hydrogel A1 having long-term adhesion properties in seawater.

[0088] Example 2: Preparation of the hydrogel having long-term adhesion in seawater of the present invention

[0089] The implementation steps of this embodiment are as follows:

[0090] A. Preparation of Monomer Mixture

[0091] The butyl acrylate hydrophobic acrylic monomer, the acrylamide and hydroxypropyl acrylate hydrophilic acrylic monomers and the N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tri(methylene))triacrylamide crosslinking monomer are mixed uniformly in a molar ratio of 30:(10+50):5, and then 30% of a mixed organic solvent of xylene, n-butanol and ethanol (mass ratio 3.5:1:0.5) and 4.0% of azobisisoheptonitrile initiator are added based on the total mass of the monomers, and mixed uniformly to obtain the monomer mixture;

[0092] B. Preparation of hydrogel precursor solution

[0093] In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 200% of a mixed organic solvent of xylene, n-butanol and ethanol (mass ratio 3.5:1:0.5) based on the total mass of the monomer mixture obtained in step A and 10% of the monomer mixture are added under nitrogen protection, mixed evenly, and then heated to a temperature of 85°C; at the same time, the temperature is maintained for 40 minutes, and then the remaining monomer mixture is evenly divided into 5 parts, and one part is added every 30 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.5% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 2 hours to obtain the hydrogel precursor solution;

[0094] C. Preparation of hydrogel

[0095] The hydrogel precursor solution prepared in step B is placed in the air, dried at room temperature, and then placed in seawater to obtain the hydrogel having long-term adhesion properties in seawater.

[0096] The product prepared in this example was analyzed using conventional infrared spectroscopy analysis. The analysis results are shown in the attached Figure 1 From the analysis results, it can be determined that the product is the hydrogel A2 with long-term adhesion properties in seawater.

[0097] Example 3: Preparation of the hydrogel with long-term adhesion in seawater of the present invention

[0098] The implementation steps of this embodiment are as follows:

[0099] A. Preparation of Monomer Mixture

[0100] Butyl acrylate and dodecyl acrylate hydrophobic acrylic monomers, acrylic acid and dimethylaminoethyl acrylate hydrophilic acrylic monomers and N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tri(methylene))triacrylamide crosslinking monomer are mixed uniformly in a molar ratio of (30+30):(10+20):10, and then 50% of xylene, a mixed organic solvent of n-butanol and ethanol (mass ratio 3.5:1:0.5) and 6.0% of azobisisobutyronitrile initiator are added based on the total mass of the monomers, and mixed uniformly to obtain the monomer mixture;

[0101] B. Preparation of hydrogel precursor solution

[0102] In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 300% of a mixed organic solvent of xylene, n-butanol and ethanol (mass ratio 3.5:1:0.5) based on the total mass of the monomer mixture obtained in step A and 5% of the monomer mixture are added under nitrogen protection, mixed evenly, and then heated to a temperature of 95°C; at the same time, the temperature is maintained for 25 minutes, and then the remaining monomer mixture is evenly divided into 12 parts, and one part is added every 20 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.6% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 4 hours to obtain the hydrogel precursor solution;

[0103] C. Preparation of hydrogel

[0104] The hydrogel precursor solution prepared in step B is placed in the air, dried at room temperature, and then placed in seawater to obtain the hydrogel having long-term adhesion properties in seawater.

[0105] The product prepared in this example was analyzed using conventional infrared spectroscopy analysis. The analysis results are shown in the attached Figure 1 From the analysis results, it can be determined that the product is the hydrogel A3 with long-term adhesion properties in seawater.

[0106] Example 4: Preparation of the hydrogel having long-term adhesion in seawater of the present invention

[0107] The implementation steps of this embodiment are as follows:

[0108] A. Preparation of Monomer Mixture

[0109] Ethyl acrylate and octadecyl acrylate hydrophobic acrylic monomers, acrylamide and hydroxyethyl acrylate hydrophilic acrylic monomers and N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tri(methylene))triacrylamide crosslinking monomer are mixed uniformly in a molar ratio of (30+20):(14+32):4, and then 25% of xylene, a mixed organic solvent of n-butanol and ethanol (mass ratio 3:1.5:0.5) and 4.0% of azobisisobutyronitrile initiator are added based on the total mass of the monomers, and mixed uniformly to obtain the monomer mixture;

[0110] B. Preparation of hydrogel precursor solution

[0111] In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 180% of a mixed organic solvent of xylene, n-butanol and ethanol (mass ratio 3:1.5:0.5) based on the total mass of the monomer mixture obtained in step A and 10% of the monomer mixture are added under nitrogen protection, mixed evenly, and then heated to a temperature of 90°C; at the same time, the temperature is maintained for 15 minutes, and then the remaining monomer mixture is evenly divided into 7 parts, and one part is added every 15 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.4% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 2.5 hours to obtain the hydrogel precursor solution;

[0112] C. Preparation of hydrogel

[0113] The hydrogel precursor solution prepared in step B is placed in the air, dried at room temperature, and then placed in seawater to obtain the hydrogel having long-term adhesion properties in seawater.

[0114] The product prepared in this example was analyzed using conventional infrared spectroscopy analysis. The analysis results are shown in the attached Figure 1 From the analysis results, it can be determined that the product is the hydrogel A4 having long-term adhesion properties in seawater.

[0115] Application Example 1: Adhesion performance test of the hydrogel with long-term adhesion performance in seawater of the present invention

[0116] The implementation method of this application example is as follows:

[0117] Test samples: hydrogels A1, A2, A3 and A4 prepared in Examples 1-4;

[0118] Comparative samples: hydrogels A0 and A01 prepared according to the method described in the literature “Hydrogel Antifouling Coating with Highly Adhesive Ability via Lipophilic Monomer”, Macromolecular Materials and Engineering, Vol. 307, 2022, p. 2100812;

[0119] Test substrate: acrylonitrile / butadiene / styrene copolymer (ABS) board, ABS board size is 100×80×1mm 3 ;

[0120] Pretreatment of test substrate: The ABS board was evenly polished with 80-grit sandpaper, then cleaned with ethanol and purified water, and dried at room temperature to constant weight.

[0121] Coating method: Coating by conventional coating method

[0122] Adhesion performance test basis: "Determination of salt water resistance of ship coatings-salt water and hot salt water immersion method" (GB / T10834-2008);

[0123] Specifically, the hydrogel coated on the surface of the substrate was placed in static seawater and immersed, and the adhesion performance of the hydrogel having long-term adhesion performance in seawater was tested by the static seawater bubble plate method. The test results are listed in the attached Figure 2 middle.

[0124] By the attached Figure 2 It can be seen that the hydrogels with long-term adhesion properties in seawater prepared in Examples 1-4 did not fall off for more than 310 days in the static bubble plate experiment, while the comparative sample hydrogels A0 and A01 began to fall off on the 150th day in the static bubble plate experiment. These results clearly show that the adhesion properties of the hydrogels of the present invention are significantly better than those of the comparative sample hydrogels A0 and A01.

[0125] Application Example 2: Real sea hanging board performance test of the hydrogel with long-term adhesion performance in seawater of the present invention

[0126] The implementation method of this application example is as follows:

[0127] Test samples: hydrogels A1, A2, A3 and A4 with long-term adhesion in seawater prepared in Examples 1-4;

[0128] Blank represents the control PVC substrate without any coating on the surface;

[0129] Test substrate: PVC, size 900×300×3mm 3 ;

[0130] Pretreatment of test substrate: The PVC board was evenly polished with 80-grit sandpaper, then cleaned with ethanol and purified water, and dried at room temperature to constant weight;

[0131] Coating method: conventional coating method;

[0132] Antifouling performance test basis: National standard "Antifouling paint sample shallow sea immersion test method" (GB / T 5370-2007);

[0133] Testing time: October 2023;

[0134] Antifouling performance test results:

[0135] The test results are shown in the attached Figure 3, wherein the blank represents the results of the biofouling test of the control plate without any coating, and A1, A2, A3 and A4 respectively represent the results of the biofouling adhesion test of the hydrogels with long-term adhesion performance in seawater for 30 days prepared in Examples 1-4.

[0136] By the attached Figure 3 It can be seen that only a small amount of biological adhesion and algae adhesion are attached to the surface of the hydrogels A1, A2, A3 and A4 with long-term adhesion in seawater of the present invention; thick biological mucosa and some algae are attached to the surface of the blank plate at the 30th day. These results fully prove that the hydrogel with long-term adhesion in seawater prepared by the present invention has good antifouling ability in the actual ocean.

Claims

1. A method for preparing a hydrogel having long-term adhesion properties in seawater, characterized in that The preparation steps of the preparation method are as follows: A. Preparation of Monomer Mixture The hydrophobic acrylic monomer, the hydrophilic acrylic monomer and the crosslinking monomer are mixed uniformly in a molar ratio of 30-80:10-60:1-10, and then 0-50% of a mixed organic solvent and 2.0-6.0% of an initiator are added based on the total mass of the monomers, and mixed uniformly to obtain the monomer mixture; B. Preparation of hydrogel precursor solution In a four-necked flask equipped with a stirrer, a condenser and a thermometer, 100-300% of a mixed organic solvent based on the total mass of the monomer mixture obtained in step A and 5-15% of the monomer mixture are added under nitrogen protection, mixed evenly, then heated to a temperature of 65-95° C., and kept at this temperature for 15-50 minutes, and then the remaining monomer mixture is evenly divided into 4-12 portions, and one portion is added every 15-35 minutes; after the monomer mixture is added, the temperature is kept for 1 hour, and then 0.15-0.6% of the above-mentioned initiator based on the total mass of the monomer mixture is added, and the reaction is continued for 1-4 hours to obtain the hydrogel precursor solution; C. Preparation of hydrogel The hydrogel precursor solution prepared in step B is placed in the air, dried at room temperature, and then placed in seawater to obtain the hydrogel having long-term adhesion properties in seawater.

2. The preparation method according to claim 1, characterized in that In step A, the hydrophobic acrylic monomer is one or more hydrophobic acrylic monomers selected from methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, dodecyl acrylate, dodecyl methacrylate, myristyl acrylate, myristyl methacrylate, hexadecyl acrylate, octadecyl acrylate or octadecyl methacrylate.

3. The preparation method according to claim 1, characterized in that In step A, the hydrophilic acrylic monomer is one or more hydrophilic acrylic monomers selected from acrylic acid, methacrylic acid, itaconic acid, acrylamide, N-hydroxymethyl acrylamide, N-hydroxyethyl acrylamide, N,N-methylenebisacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate or 3-(dimethylamino)propyl acrylate, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, methyl 2-(hydroxymethyl)acrylate or ethyl 2-(hydroxymethyl)acrylate.

4. The preparation method according to claim 1, characterized in that In step A, the crosslinking monomer is one or more crosslinking monomers selected from 3,5,6-tris(N-hydroxymethylacrylamide)-4-(2-aminoethyl)-1,2-benzenediol hydrochloride, N,N',N"-((2,4,6-trihydroxybenzene-1,3,5-triyl)tris(methylene))triacrylamide, N,N',N"-((3,6-dihydroxy-5-methylbenzene-1,2,4-triyl)tris(methylene))triacrylamide or N,N',N"-((6-chloro-3,5-dihydroxybenzene-1,2,4-triyl)tris(methylene))triacrylamide.

5. The preparation method according to claim 1, characterized in that In step A, the initiator is one or more initiators selected from azobisisobutyronitrile, azobisisoheptanenitrile, dibenzoyl peroxide, di(2-ethylhexyl) peroxydicarbonate, di-tert-butyl peroxide, dodecyl peroxide, tert-butyl perbenzoate, potassium persulfate or ammonium persulfate.

6. The preparation method according to claim 1, characterized in that In step A, the organic solvent is one or more organic solvents selected from xylene, methyl isobutyl ketone, butyl acetate, n-butanol, ethanol or cyclohexanone.

7. A hydrogel having long-term adhesion in seawater prepared according to the preparation method according to any one of claims 1 to 6.

8. The hydrogel according to claim 7, characterized in that The adhesion property of the hydrogel in seawater is that it will not fall off from the surface of the substrate after being immersed in seawater.

9. The hydrogel according to claim 7, characterized in that The adhesion performance of the hydrogel in seawater is maintained for more than 310 days.

10. Use of the hydrogel according to any one of claims 7 to 9 in preventing marine fouling.

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