An amphiphilic antifouling coating and its preparation method

Abstract

This invention relates to the field of organosilicon antifouling coatings, specifically to an amphiphilic antifouling coating and its preparation method; comprising the following components by weight: trimethoxy-terminated polydimethylsiloxane, organosilicon, prepolymer, polyvinylpyrrolidone, 3-aminopropyltriethoxysilane, vinyltrimethoxysilane, fumed silica, acetylenecyclohexanol, and dibutyltin dilaurate; this invention utilizes a redox initiation system to prepare silane-terminated hydrophilic polyvinylpyrrolidone (PVP) molecules at room temperature, and combines PVP with an organosilicon matrix through chemical bonds formed by silane condensation; compared with the prior art for preparing hydroxyl-terminated polyvinylpyrrolidone, the steps are simple and the reaction conditions are mild.

Description

Technical Field

[0001] This invention relates to the field of silicone antifouling coatings, specifically to an amphiphilic antifouling coating and its preparation method. Background Technology

[0002] Organosilicon antifouling coatings are used in marine antifouling, sunlight exposure, and mechanical corrosion protection. They are mainly composed of organosilicon polymers, weather-resistant curing agents, and additives, possessing excellent physical and chemical properties. They can replace traditional kerosene and solvent-based anti-corrosion coatings, making them an environmentally friendly and highly efficient coating material. The hydrophobic surface of organosilicon coatings has low surface energy, making it difficult for fouling organisms to bind to them through hydrogen bonds. Many large organisms that secrete catechol adhesives (such as mussels and barnacles) cannot adhere firmly. However, the adhesion mechanisms of fouling organisms on coatings differ. For example, diatoms tend to adhere more strongly to hydrophobic surfaces through hydrophobic interactions, making them difficult to separate even under high hydrodynamic shear forces at high speeds. Furthermore, hydrophobic coatings cannot resist the accumulation and growth of marine slime layers, which are mainly composed of bacteria, diatoms, and secreted extracellular polymer matrices. To improve the antifouling properties of the coating, hydrophilic segments are introduced into the hydrophobic matrix. Poly(N-vinylpyrrolidone) (PVP) and polyethylene glycol (PEG) are both hydrophilic polymers containing hydroxyl groups. When introduced into hydrophobic coatings, they can tightly bind water molecules to form a hydrated layer on the coating surface, resisting protein adsorption and cell adhesion.

[0003] To enhance the compatibility of hydrophilic and hydrophobic phases in silicone-based amphiphilic coatings and improve their adhesion to substrates, polymers containing polar groups (epoxy groups, urethanes, urea, etc.) and hydrophilic polymers are end-capped with reactive groups before being introduced into the silicone network. This significantly improves the overall performance of the coating. Polar groups improve the mechanical properties and adhesion to the substrate, while hydrophilic segments improve the coating's antifouling properties. End-capped reactive groups can be used to crosslink other materials or form chemical bonds with the substrate, thereby increasing the coating's adhesion. Zhang et al. combined bissilane-terminated polyurea (SPU) with stereosiloxane nanoclusters and reactive amphiphilic polymers (RAP) to prepare a polysiloxane coating with antifouling capabilities and strong substrate adhesion. Bissilane-terminated polyurea containing silane groups can form reactive silanol groups, which can be used to connect other materials, while urea groups can form strong hydrogen bonds with other polymer chains or substrates, providing strong substrate adhesion to the bottom of the coating (Lin XB, Xie QY, Ma CF, Zhang GZ. Self-healing, highly elastic and amphiphilic silicone-based polyurethane for antifouling coatings[J]. JOURNAL OF MATERIALS CHEMISTRY B, 2021, 9(5): 1384-94.). Tong et al. synthesized hydroxyl-terminated polyvinylpyrrolidone by reacting β-mercaptoethanol, vinylpyrrolidone and a macromolecular free radical initiator at 85℃ for 24h, and mixed it with an organosilicon polymer with terminal alkoxy groups embedded in urethane bonds to prepare an amphiphilic coating (https: / / doi.org / 10.1016 / j.colsurfb.2022.112392). The amphiphilic organosilicon antifouling coatings disclosed in patent literature are mainly modified with polyethylene glycol and polyurethane. Examples include CN115074008A (An organosilicon antifouling coating and its preparation method), CN113773436B (An amphiphilic organosilicon coating and its preparation method and application), CN115595063A (A surface amphoteric ionization organosilicon antifouling coating and its preparation method), CN113717626A (A marine antifouling coating and its preparation method and application), and CN111848962B (An amphiphilic benzoxazine and polyethylene glycol modified organosilicon resin and its preparation method and application). Existing technologies involve harsh reaction conditions, requiring prolonged heating reactions and numerous synthesis steps, which are not conducive to industrial production. Summary of the Invention

[0004] Organosilicon antifouling coatings are among the most widely used non-toxic and environmentally friendly antifouling coatings. However, traditional organosilicon coatings have hydrophobic surfaces, making it easier for marine biofouling organisms to accumulate on the coating surface due to hydrophobic interactions, thus affecting the antifouling effect. Amphiphilic coatings improve the antifouling properties of polymer-based biofouling prevention coatings, but due to the incompatibility of the hydrophilic and hydrophobic phases, the hydrophilic segments are prone to disintegration due to water absorption and swelling, reducing the mechanical properties and service life of the coating. To address the shortcomings of existing technologies, this invention provides an amphiphilic antifouling coating and its preparation method.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An amphiphilic antifouling coating comprises the following components in parts by weight: 40-60 parts of trimethoxy-terminated polydimethylsiloxane, 40-60 parts of organosilicon, 8-15 parts of prepolymer, 8-15 parts of polyvinylpyrrolidone, 0.8-0.9 parts of 3-aminopropyltriethoxysilane, 9-10 parts of vinyltrimethoxysilane, 2-3 parts of fumed silica, 0.3-0.4 parts of acetylenecyclohexanol, and 0.3-0.4 parts of dibutyltin dilaurate.

[0007] The amphiphilic antifouling coating comprises the following components in parts by weight: 40-60 parts of trimethoxy-terminated polydimethylsiloxane, 40 parts of organosilicon, 8 parts of prepolymer, 8 parts of polyvinylpyrrolidone, 0.8 parts of 3-aminopropyltriethoxysilane, 9 parts of vinyltrimethoxysilane, 2 parts of fumed silica, 0.3 parts of acetylenecyclohexanol, and 0.3 parts of dibutyltin dilaurate.

[0008] The amphiphilic antifouling coating comprises the following components in parts by weight: 50 parts of trimethoxy-terminated polydimethylsiloxane, 50 parts of organosilicon, 10 parts of prepolymer, 10 parts of polyvinylpyrrolidone, 0.8 parts of 3-aminopropyltriethoxysilane, 10 parts of vinyltrimethoxysilane, 3 parts of fumed silica, 0.4 parts of acetylenecyclohexanol, and 0.3 parts of dibutyltin dilaurate.

[0009] The amphiphilic antifouling coating comprises the following components in parts by weight: 60 parts of trimethoxy-terminated polydimethylsiloxane, 60 parts of organosilicon, 15 parts of prepolymer, 15 parts of polyvinylpyrrolidone, 0.9 parts of 3-aminopropyltriethoxysilane, 10 parts of vinyltrimethoxysilane, 3 parts of fumed silica, 0.4 parts of acetylenecyclohexanol, and 0.4 parts of dibutyltin dilaurate.

[0010] The preparation method of the amphiphilic antifouling coating includes the following steps:

[0011] 1) Add 60-80 ml of tetrahydrofuran and 30-40 g of N-vinylpyrrolidone to a 250 ml three-necked flask, purge with nitrogen and stir for 10-20 min. Dissolve 0.1-0.3 g of ammonium persulfate and 0.06-0.12 g of calcium chloride in 2 g of water to form aqueous solution A. Add aqueous solution A dropwise to the three-necked flask, then add 1.5-2 g of TBPDD dropwise to the three-necked flask, react again for 30-40 min, and remove tetrahydrofuran by rotary evaporation. Finally, the desired polyvinylpyrrolidone is prepared.

[0012]

[0013] 2) Add PEG200 dropwise to a three-necked flask containing IPDI (PEG200 to IPDI molar ratio of 1:2), and add about 2-3‰ dibutyltin dilaurate as a catalyst. Purge with nitrogen and stir. Control the reaction temperature at 25-35℃. After about 70-80 minutes, add γ-aminopropyltriethoxysilane in the same molar ratio as IPDI, and react for another 40-60 minutes to obtain the desired prepolymer.

[0014] 3) Mix trimethoxy-terminated polydimethylsiloxane, prepolymer, and polyvinylpyrrolidone evenly. Then add 50-60 parts (by weight) of organosilicon to the mixed solution. Then add accelerator, crosslinking agent, reinforcing agent, coupling agent, inhibitor, and catalyst, and ensure that the product is mixed evenly after each addition. Finally, an amphiphilic antifouling coating is obtained.

[0015] In step 3), the amount of trimethoxy-terminated polydimethylsiloxane is 50-60 parts; the amount of polyvinylpyrrolidone prepared in the first step is 10-15 parts of the matrix; and the amount of prepolymer prepared in the second step is 10-15 parts.

[0016] In step 3), 3-aminopropyltriethoxysilane is used as an accelerator, with 0.8-0.9 parts; vinyltrimethoxysilane is used as a coupling agent, with 9-10 parts; acetylenol is used as an inhibitor, with 0.3-0.4 parts; dibutyltin dilaurate is used as a catalyst, with 0.3-0.4 parts; and fumed silica is used as a reinforcing agent, with 2-3 parts.

[0017] Compared with the prior art, the beneficial effects of the invention are: the invention utilizes a redox initiation system to prepare silane-terminated hydrophilic polyvinylpyrrolidone (PVP) molecules at room temperature, and combines PVP with the organosilicon matrix through chemical bonds formed by silane condensation;

[0018] 1. Organosilicon compounds containing silicon-nitrogen bonds and ammonium persulfate are used as redox initiators to initiate the polymerization of N-vinylpyrrolidone. The monomer is in the solvent phase and the initiator is in the aqueous phase. Alkali metal or alkaline earth metal ions can stabilize the free radicals generated in the aqueous phase, thereby increasing the initiation rate. The reaction can be carried out at room temperature and is easy to control.

[0019] 2. The generated Si-PVP has silaneoxy groups at the end, which allows it to be linked with the organosilicon matrix through silaneoxy condensation, thereby improving the compatibility between the hydrophilic and hydrophobic phases.

[0020] 3. The end groups of the generated Si-PPU are silaneoxy groups, which enable it to be linked with the organosilicon matrix through silaneoxy condensation. The urethane bond plays a good role in improving the adhesion between the coating and the substrate. Attached Figure Description

[0021] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0022] Figure 1 Nuclear magnetic resonance spectrum of polyvinylpyrrolidone (Si-PVP)

[0023] Figure 2 Gel chromatography curve of polyvinylpyrrolidone (Si-PVP)

[0024] Figure 3 Flowchart for the preparation of biofouling-resistant silicone coatings;

[0025] Figure 4 SEM image of the coating;

[0026] Figure 5 Adhesion between coating and cement substrate

[0027] Figure 6 Image of coating applied to cement slab

[0028] in Figure 1 The left image is the proton spectrum, and the right image is the carbon spectrum. Detailed Implementation

[0029] The present invention will be further described in detail below through embodiments. These embodiments are only used to illustrate the present invention and do not limit the scope of the present invention.

[0030] Example 1: An amphiphilic antifouling coating comprising the following components in parts by weight: 40-60 parts of trimethoxy-terminated polydimethylsiloxane, 40 parts of organosilicon, 8 parts of prepolymer, 8 parts of polyvinylpyrrolidone, 0.8 parts of 3-aminopropyltriethoxysilane, 9 parts of vinyltrimethoxysilane, 2 parts of fumed silica, 0.3 parts of acetylenecyclohexanol, and 0.3 parts of dibutyltin dilaurate.

[0031] Example 2: An amphiphilic antifouling coating comprising the following components in parts by weight: 50 parts of trimethoxy-terminated polydimethylsiloxane, 50 parts of organosilicon, 10 parts of prepolymer, 10 parts of polyvinylpyrrolidone, 0.8 parts of 3-aminopropyltriethoxysilane, 10 parts of vinyltrimethoxysilane, 3 parts of fumed silica, 0.4 parts of acetylenecyclohexanol, and 0.3 parts of dibutyltin dilaurate.

[0032] Example 3: An amphiphilic antifouling coating comprising the following components in parts by weight: 60 parts of trimethoxy-terminated polydimethylsiloxane, 60 parts of organosilicon, 15 parts of prepolymer, 15 parts of polyvinylpyrrolidone, 0.9 parts of 3-aminopropyltriethoxysilane, 10 parts of vinyltrimethoxysilane, 3 parts of fumed silica, 0.4 parts of acetylenecyclohexanol, and 0.4 parts of dibutyltin dilaurate.

[0033] The preparation method of amphiphilic antifouling coating includes the following steps:

[0034] 1) Add 60-80 ml of tetrahydrofuran and 30-40 g of N-vinylpyrrolidone to a 250 ml three-necked flask, purge with nitrogen and stir for 10-20 min. Dissolve 0.1-0.3 g of ammonium persulfate and 0.06-0.12 g of calcium chloride in 2 g of water to form aqueous solution A. Add aqueous solution A dropwise to the three-necked flask, then add 1.5-2 g of TBPDD dropwise to the three-necked flask, react again for 30-40 min, and remove tetrahydrofuran by rotary evaporation. Finally, the desired polyvinylpyrrolidone (Si-PVP) is prepared.

[0035]

[0036] 2) Add PEG200 dropwise to a three-necked flask containing IPDI (PEG200 to IPDI molar ratio of 1:2), and add about 2-3‰ dibutyltin dilaurate as a catalyst. Purge with nitrogen and stir, and control the reaction temperature at 25-35℃, preferably around 30℃. After about 70-80 minutes, add γ-aminopropyltriethoxysilane dropwise in the same molar ratio as the IPDI, and react for another 40-60 minutes to obtain the desired prepolymer (Si-PPU).

[0037] 3) Mix trimethoxy-terminated polydimethylsiloxane, the prepolymer, and polyvinylpyrrolidone evenly, then add 50-60 parts (by weight).

[0038] Organosilicon is added to a mixed solution, followed by accelerators, crosslinking agents, reinforcing agents, coupling agents, inhibitors, and catalysts. Each addition ensures that the product is thoroughly mixed with stirring, ultimately yielding an amphiphilic antifouling coating.

[0039] In step 3), the amount of trimethoxy-terminated polydimethylsiloxane (trimethoxy-terminated 107 silicone rubber) is 50-60 parts (by weight); the amount of polyvinylpyrrolidone (Si-PVP) prepared in the first step is 10-15 parts (by weight) of matrix; and the amount of prepolymer (Si-PPU) prepared in the second step is 10-15 parts (by weight).

[0040] The 3-aminopropyltriethoxysilane is used as an accelerator, with 0.8-0.9 parts (by weight); vinyltrimethoxysilane is used as a coupling agent, with 9-10 parts (by weight); acetylenecyclohexanol is used as an inhibitor, with 0.3-0.4 parts (by weight); dibutyltin dilaurate is used as a catalyst, with 0.3-0.4 parts (by weight); and fumed silica is used as a reinforcing agent, with 2-3 parts (by weight).

[0041] In use, the amphiphilic antifouling coating is applied to the substrate and allowed to crosslink and cure in air at room temperature for contact angle testing and subsequent practical applications. Dumbbell-shaped samples are prepared by pouring the coating into a PTFE mold and allowed to cure before mechanical property testing.

[0042] Table 1. Contact angle and surface free energy of amphiphilic antifouling coatings

[0043]

[0044] This invention uses a silicon-nitrogen bond-containing organosilicon compound and ammonium persulfate as initiators to initiate the polymerization of N-vinylpyrrolidone. A one-step reaction simultaneously generates polyvinylpyrrolidone and introduces silanoxy groups at the molecular chain ends. Compared to existing techniques for preparing hydroxyl-terminated polyvinylpyrrolidone, this method is simpler and the reaction conditions are milder. The resulting Si-PPU has silanoxy end groups, enabling it to condense with the organosilicon matrix. The urethane bonds effectively enhance the adhesion between the coating and the substrate. This invention offers a simple preparation process with high energy consumption and a short reaction time, improving the mechanical properties and adhesion of amphiphilic coatings by introducing silane-terminated hydrophilic or amphiphilic polymers containing polar groups (epoxy groups, urethanes, urea, etc.) into the organosilicon network.

Claims

1. An amphiphilic antifouling coating, characterized in that, It contains the following components in parts by weight: 40-60 parts of trimethoxy-terminated polydimethylsiloxane, 40-60 parts of organosilicon, 8-15 parts of prepolymer, 8-15 parts of polyvinylpyrrolidone, 0.8-0.9 parts of 3-aminopropyltriethoxysilane, 9-10 parts of vinyltrimethoxysilane, 2-3 parts of fumed silica, 0.3-0.4 parts of acetylenecyclohexanol, and 0.3-0.4 parts of dibutyltin dilaurate; In this process, 60–80 ml of tetrahydrofuran and 30–40 g of N-vinylpyrrolidone are added to a 250 ml three-necked flask. Nitrogen gas is introduced and the mixture is stirred for 10–20 min. 0.1–0.3 g of ammonium persulfate and 0.06–0.12 g of calcium chloride are dissolved in 2 g of water to form aqueous solution A. This aqueous solution A is added dropwise to the three-necked flask, followed by the addition of 1.5–2 g of TBPDD. The reaction is repeated for 30–40 min, and the tetrahydrofuran is removed by rotary evaporation. Finally, the desired polyvinylpyrrolidone is prepared. PEG200 was added dropwise to a three-necked flask containing IPDI at a molar ratio of 1:

2. Approximately 2-3‰ of dibutyltin dilaurate was added as a catalyst. Nitrogen gas was introduced and the mixture was stirred. The reaction temperature was controlled at 25-35°C. After approximately 70-80 minutes, γ-aminopropyltriethoxysilane was added dropwise in an equimolar ratio to the IPDI. The reaction was then continued for another 40-60 minutes to obtain the desired prepolymer.

2. The amphiphilic antifouling coating according to claim 1, characterized in that, It contains the following components in parts by weight: 40-60 parts of trimethoxy-terminated polydimethylsiloxane, 40 parts of organosilicon, 8 parts of prepolymer, 8 parts of polyvinylpyrrolidone, 0.8 parts of 3-aminopropyltriethoxysilane, 9 parts of vinyltrimethoxysilane, 2 parts of fumed silica, 0.3 parts of acetylenecyclohexanol, and 0.3 parts of dibutyltin dilaurate.

3. The amphiphilic antifouling coating according to claim 1, characterized in that, The product contains the following components in parts by weight: 50 parts of trimethoxy-terminated polydimethylsiloxane, 50 parts of organosilicon, 10 parts of prepolymer, 10 parts of polyvinylpyrrolidone, 0.8 parts of 3-aminopropyltriethoxysilane, 10 parts of vinyltrimethoxysilane, 3 parts of fumed silica, 0.4 parts of acetylenecyclohexanol, and 0.3 parts of dibutyltin dilaurate.

4. The amphiphilic antifouling coating according to claim 1, characterized in that, The product contains the following components in parts by weight: 60 parts of trimethoxy-terminated polydimethylsiloxane, 60 parts of organosilicon, 15 parts of prepolymer, 15 parts of polyvinylpyrrolidone, 0.9 parts of 3-aminopropyltriethoxysilane, 10 parts of vinyltrimethoxysilane, 3 parts of fumed silica, 0.4 parts of acetylenecyclohexanol, and 0.4 parts of dibutyltin dilaurate.

5. A method for preparing an amphiphilic antifouling coating according to claim 1, characterized in that, Includes the following steps: 1) Add 60-80 ml of tetrahydrofuran and 30-40 g of N-vinylpyrrolidone to a 250 ml three-necked flask, purge with nitrogen and stir for 10-20 min. Dissolve 0.1-0.3 g of ammonium persulfate and 0.06-0.12 g of calcium chloride in 2 g of water to form aqueous solution A. Add aqueous solution A dropwise to the three-necked flask, then add 1.5-2 g of TBPDD dropwise to the three-necked flask. React again for 30-40 min, and remove tetrahydrofuran by rotary evaporation. Finally, the desired polyvinylpyrrolidone is prepared. 2) PEG200 is added dropwise to a three-necked flask containing IPDI, with a molar ratio of PEG200 to IPDI of 1:

2. About 2-3‰ of dibutyltin dilaurate is added as a catalyst. Nitrogen gas is introduced and the mixture is stirred. The reaction temperature is controlled at 25-35℃. After about 70-80 minutes, γ-aminopropyltriethoxysilane is added dropwise in a molar ratio equal to that of IPDI. The reaction is then carried out for another 40-60 minutes to obtain the desired prepolymer. 3) Mix trimethoxy-terminated polydimethylsiloxane, prepolymer, and polyvinylpyrrolidone evenly. Then add 50-60 parts of organosilicon to the mixed solution, followed by accelerator, crosslinking agent, reinforcing agent, coupling agent, inhibitor, and catalyst. Ensure that the product is mixed evenly after each addition to obtain an amphiphilic antifouling coating. In step 3), the trimethoxy-terminated polydimethylsiloxane is 50-60 parts; the polyvinylpyrrolidone prepared in the first step is 10-15 parts of the matrix, and the prepolymer prepared in the second step is 10-15 parts. In step 3), 3-aminopropyltriethoxysilane is used as a promoter, with 0.8-0.9 parts; vinyltrimethoxysilane is used as a coupling agent, with 9-10 parts; acetylenol is used as an inhibitor, with 0.3-0.4 parts; dibutyltin dilaurate is used as a catalyst, with 0.3-0.4 parts; and fumed silica is used as a reinforcing agent, with 2-3 parts.

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