Grafted long-chain hyperbranched organosilicon polymer antifouling coating of quaternary ammonium salt and method for preparing the same

Abstract

The application belongs to the field of marine antifouling, and particularly relates to a grafted long-chain hyperbranched organosilicon polymer antifouling coating and a preparation method thereof. The antifouling coating is obtained by grafting a long-chain hyperbranched organosilicon polymer, a crosslinking agent bisphenol A diglycidyl ether and a catalyst; the mass ratio of the grafted long-chain hyperbranched organosilicon polymer, the bisphenol A diglycidyl ether and the catalyst is 10-100:1:0.01-0.1. The grafted long-chain hyperbranched organosilicon polymer antifouling coating has a synergistic antifouling material surface with amphiphilicity, low surface energy and bactericidal property, and the prepared antifouling coating has excellent mechanical properties and static antifouling performance. The antifouling coating does not cause any pollution to the ecological environment, and has a wide application prospect in the field of marine antifouling.

Description

Technical Field

[0001] This invention belongs to the field of marine antifouling, and specifically relates to an antifouling coating of a long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt and its preparation method. Background Technology

[0002] Marine biofouling refers to the biological scale formed by the adhesion and growth of microorganisms, plants, and animals on the surface of marine facilities, which has a profound and adverse impact on the development of marine resources. With increasingly stringent marine environmental protection requirements, antifouling coating technologies that release toxic biocides will gradually be restricted. Fouling-removing silicone-based antifouling coatings, due to their low surface energy, low modulus, and smooth surface, make it difficult for fouling organisms to adhere to the surface or to adhere firmly, making them a green approach to solving the fouling problem. However, this technology also has drawbacks: ① The coating cannot remove the slime layer secreted by algae and bacteria in low-velocity seawater environments, resulting in poor antifouling performance on static underwater facilities; ② The coating is generally a silicone elastomer with low mechanical strength, making it susceptible to damage and reducing its lifespan; ③ The adhesion between the coating and the substrate is poor, requiring a specially designed intermediate coating layer in practical applications to prevent peeling.

[0003] Hyperbranched polymers, as a typical class of three-dimensional topological polymers, differ from linear polymers in that they possess highly branched main chains and extremely high terminal functional group densities, allowing for the derivation of various functional polymer materials through end-group modification. Positively charged quaternary ammonium salts can penetrate and disrupt cell walls and membrane structures, inhibiting enzyme or protein activity and affecting cellular metabolic processes, ultimately leading to cell death. Asri et al. prepared an antibacterial coating by grafting quaternary ammonium salt compounds onto hyperbranched polyurea. The hyperbranched polyurea exhibited a much higher density of quaternary ammonium molecules than linear polymers, resulting in a stronger contact-killing effect against Staphylococcus aureus, reaching 1600 CFU / cm³. 2 The kill rate is as high as 99.99%. However, hyperbranched polymers, due to their short branched chains and lack of inter-chain cross-entanglement, exhibit brittle and amorphous properties, making them difficult to use independently as structural materials. They usually need to be cross-linked and cured with linear polymers to compensate for their insufficient mechanical properties. In addition, the synthesis and control of hyperbranched polymers are relatively complex, requiring precise control of reaction conditions and monomer addition methods. Poor control of reaction conditions or operations can easily lead to uneven polymer distribution, difficulty in controlling molecular weight, or unstable physical properties. Summary of the Invention

[0004] To address the problem of poor static antifouling ability and durability of current silicone-based antifouling coatings, this invention provides a long-chain hyperbranched silicone polymer antifouling coating grafted with quaternary ammonium salt and its preparation method.

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

[0006] A long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt is obtained by curing the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt, the crosslinking agent bisphenol A diglycidyl ether, and the catalyst; the mass ratio of the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt, the bisphenol A diglycidyl ether, and the catalyst is 10-100:1:0.01-0.1.

[0007] The catalyst is one or more of 2,4,6-tris(dimethylaminomethyl)phenol, triethanolamine, dimethylethanolamine, boron trifluoride ether, boron trifluoride ether complex, triphenylphosphine, and potassium persulfate.

[0008] The grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer is prepared by grafting quaternary ammonium salt onto the long-chain hyperbranched organosilicon polymer, and the mass ratio of quaternary ammonium salt to long-chain hyperbranched organosilicon polymer is 1 to 5:1.

[0009] The quaternary ammonium salt is one or more of the following: 2,3-epoxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride solution, (2-aminoethyl)trimethylammonium chloride hydrochloride, 2,3-dihydroxypropyl-trimethylammonium chloride, (chloromethylene)dimethylammonium chloride, 3-bromopropyltrimethylammonium bromide, 2-bromoethyltrimethylammonium bromide, 2-(4-acetamidophenyl)-N,N,N-trimethylethylammonium bromide, (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide, allyltriethylammonium bromide, 4-methoxy-phenylammonium bromide, and dimethyldiallylammonium chloride.

[0010] The long-chain hyperbranched polymer is synthesized by a one-step polycondensation method (B3) of a hydrophilic dihydroxyl-terminated long-chain polymer (A2) and a silane coupling agent in an organic solvent, dimethyl sulfoxide, and under high temperature conditions. The mass ratio of the hydroxyl-terminated long-chain polymer to the silane coupling agent is 1.5 to 15:1.

[0011] The A2+B3 one-step polycondensation method involves polycondensing A2 type monomers (hydroxyl-terminated long-chain polymers containing two functional hydroxyl groups) with B3 type monomers (silane coupling agents containing three functional ethoxy or methoxy groups).

[0012] The hydrophilic hydroxyl-terminated long-chain polymer is one or more of polyethylene glycol, polypropylene glycol, polytetrahydrofuran, polycaprolactone diol, and dihydroxyl-terminated polysiloxane, with a molecular weight between 200 and 2000.

[0013] The silane coupling agent is 3-aminopropyltriethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, hydroxymethyltriethoxysilane, 3-chloropropyltriethoxysilane, 3-bromopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 4-chlorophenyltriethoxysilane, 4-(triethoxysilyl)aniline, 4-aminobutyltriethoxysilane, propyltriethoxysilane isocyanate, 5,6-epoxyhexyltriethoxysilane. oxysilanes, 3-thiocyanopropyltriethoxysilane, 3-glycidyl ether oxypropyltriethoxysilane, vinyltrimethoxysilane, chloromethyltrimethoxysilane, allyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 5-bromopentyltrimethoxysilane, p-chlorophenyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-bromopropyltrimethoxysilane, 3-iodopropyltrimethoxysilane, 4-bromobutyltrimethoxysilane Alkane, 6-bromohexyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, m-aminophenyltrimethoxysilane, 11-chloroundecyltrimethoxysilane, acryloyloxypropyltrimethoxysilane, acrylamidepropyltrimethoxysilane, 3-isocyanate-propyltrimethoxysilane, N-aminoethyl-γ-aminopropyltrimethoxysilane, methacryloyloxymethyltrimethoxysilane, 3-(isobutyloxy)propyltrimethoxysilane, One or more of the following: 11-allyloxyundecyltrimethoxysilane, 3-(3-aminophenoxy)propyltrimethoxysilane, 3-(N-allylamino)propyltrimethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, [8-(epoxypropyloxy)-n-octyl]trimethoxysilane, and [3-(6-aminohexylamino)propyl]trimethoxysilane.

[0014] This invention provides a method for preparing a long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt, specifically:

[0015] Step 1: First, a certain amount of dihydroxyl-terminated long-chain polymer and silane coupling agent were added to a three-necked flask containing dimethyl sulfoxide for dissolution and stirring until homogeneous. Nitrogen gas was introduced and the reaction was carried out at 100°C for 1 hour. Subsequently, the temperature was gradually increased to 150°C and the reaction was continued for 24 hours before being stopped. The crude product was then rotary evaporated at 80°C to remove unreacted monomers and solvents, yielding a long-chain hyperbranched organosilicon polymer.

[0016] Step 2: Dissolve an excess of quaternary ammonium salt in deionized water, control the pH of the solution between 9 and 10, then add the long-chain hyperbranched organosilicon polymer and react at 80°C for 12 hours before stopping. Wash the crude product, rotary evaporate and vacuum dry to obtain the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt.

[0017] Step 3: Dissolve the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt, bisphenol A diglycidyl ether and catalyst in tetrahydrofuran and mix evenly. Then, apply the solution to different substrates and crosslink and cure at 70°C to obtain an antifouling coating of the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt.

[0018] An application of the grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating, specifically its application in the marine antifouling field.

[0019] Beneficial effects of the present invention

[0020] The present invention provides a long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salts, which constructs a synergistic antifouling material surface with amphiphilicity, low surface energy, and bactericidal properties. The prepared antifouling coating exhibits excellent mechanical and static antifouling properties. The antifouling coating of the present invention does not cause any pollution to the ecological environment, and the raw materials are readily available, the preparation method is simple and easy to implement, and it is highly practical. Specifically:

[0021] (1) The grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating of the present invention uses a hydrophilic long-chain hyperbranched organosilicon topological structure polymer as the antifouling matrix resin. Unlike the linear polymers currently studied more extensively, the long-chain hyperbranched organosilicon polymer combines the advantages of both hyperbranched and linear polymers, featuring strong entanglement of branched chains, uniform crystal arrangement, and a large number of terminal functional groups. After crosslinking and curing, the highly entangled molecular chains and high crosslinking density can significantly improve the mechanical properties and adhesion of the coating, effectively enhancing the long-term durability of the antifouling coating in complex and even extreme marine environments. In addition, the long-chain hyperbranched polymer also has low viscosity and good solubility in both water and organic solvents, which makes it easier for them to flow during processing, while maintaining high viscosity under low shear conditions, which is beneficial to increasing the stability of the molded product.

[0022] (2) The grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating of the present invention chemically grafts bactericidal quaternary ammonium molecules onto the end groups of the hydrophilic long-chain hyperbranched organosilicon topology polymer. The inherent amphiphilic and low surface energy characteristics of the antifouling coating surface, combined with the high density of bactericidal quaternary ammonium molecules, synergistically and effectively enhance the static antifouling ability of the antifouling coating, providing a design basis and technical foundation for the development of long-lasting and durable high-performance antifouling coatings.

[0023] (3) The grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating of the present invention is green and environmentally friendly, the raw materials are readily available, it is highly practical, the preparation process is simple and efficient, it is universal and easy to promote. Attached Figure Description

[0024] Figure 1 Infrared spectra of the long-chain hyperbranched organosilicon polymer before and after grafting quaternary ammonium salt provided by the present invention (Example 1).

[0025] Figure 2 Matrix-assisted laser time-of-flight mass spectrometry of long-chain hyperbranched organosilicon polymers provided by the present invention (Example 1).

[0026] Figure 3 Static water contact angle photograph of the long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt provided by this invention.

[0027] Figure 4 An appearance diagram of the long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt provided by the present invention (Example 1). Detailed Implementation

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0029] The long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt of the present invention constructs a synergistic antifouling material surface with amphiphilicity, low surface energy, and bactericidal properties. The prepared antifouling coating exhibits excellent mechanical and static antifouling properties. This antifouling coating will not cause any pollution to the ecological environment and has broad application prospects in the field of marine antifouling.

[0030] Example 1:

[0031] (1) First, polyethylene glycol (polyethylene glycol-200) (10 mmol, 2 g) with a molecular weight of 200 and 3-aminopropyltriethoxysilane (4.2 mmol, 0.93 g) were added to a three-necked flask containing dimethyl sulfoxide for dissolution and stirring. Nitrogen gas was introduced and the reaction was carried out at 100 °C for 1 h. Then the temperature was gradually increased to 150 °C and the reaction was continued for 24 h before stopping. The crude product was rotary evaporated at 80 °C to remove unreacted monomers and solvents to obtain a long-chain hyperbranched organosilicon polymer.

[0032] (2) Dissolve 4 g of 2,3-epoxypropyltrimethylammonium chloride in 20 mL of deionized water. Adjust the pH of the solution to between 9 and 10 with 0.01 mol / L NaOH solution. Then add 2 g of long-chain hyperbranched organosilicon polymer and react at 80 °C for 12 h. After that, stop the reaction. Wash the crude product three times with a large amount of cold isopropanol, remove the solvent by rotary evaporation, and then vacuum dry at 40 °C for 12 h to obtain the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt (see...). Figure 1 );

[0033] (3) 2g of grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer, 0.2g of bisphenol A diglycidyl ether, and 0.002g of 2,4,6-tris(dimethylaminomethyl)phenol were dissolved in tetrahydrofuran and mixed evenly. The solution was then applied to different substrates (in this example, the substrate was a glass slide) and crosslinked and cured at 70°C to obtain a grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating.

[0034] Depend on Figure 1 The infrared spectrum shows that at 1068 cm⁻¹ -1 and 1063cm -1 The infrared absorption peak belongs to Si-O-Si, at 3351 cm⁻¹. -1 The NH antisymmetric stretching vibration belongs to primary amines, while after grafting with quaternary ammonium salts, it reaches 3296 cm⁻¹. -1 The characteristic peak appearing at this point belongs to the antisymmetric stretching vibration of NH in secondary amines. The peak at 1647 cm⁻¹... 1 The infrared absorption peak at 1480 cm⁻¹ belongs to the bending vibration of the quaternary ammonium group. -1 The position corresponds to the asymmetric stretching vibration of CH in -CH3, which is characteristic of highly methylated quaternary ammonium salts. This demonstrates the successful synthesis of long-chain hyperbranched organosilicon polymers grafted with quaternary ammonium salts. Figure 2 The matrix-assisted laser time-of-flight mass spectrometry (MAGMS) shows that the prepared polymers have a wide and high molecular weight distribution, indicating the presence of a large number of long-chain hyperbranched polymers with relative molecular masses ranging from 5044 to 204595. Figure 3 The static water contact angle photographs show that the surface of the long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt is hydrophilic, with a water contact angle of 81°. Figure 4 The appearance of the grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating shows that the coating is transparent, smooth and uniform.

[0035] Example 2

[0036] (1) First, polyethylene glycol (polyethylene glycol-400) (10 mmol, 4 g) with a molecular weight of 400 and 3-aminopropyltriethoxysilane (4.2 mmol, 0.93 g) were added to a three-necked flask containing dimethyl sulfoxide for dissolution and stirring. Nitrogen gas was introduced and the reaction was carried out at 100 °C for 1 h. Then the temperature was gradually increased to 150 °C and the reaction was continued for 24 h before stopping. The crude product was rotary evaporated at 80 °C to remove unreacted monomers and solvents to obtain a long-chain hyperbranched organosilicon polymer.

[0037] (2) Dissolve 4g of 2,3-epoxypropyltrimethylammonium chloride in 20mL of deionized water, adjust the pH of the solution to between 9 and 10 with 0.01mol / L NaOH solution, then add 2g of long-chain hyperbranched organosilicon polymer and react at 80℃ for 12h before stopping. Wash the crude product three times with a large amount of cold isopropanol, remove the solvent by rotary evaporation, and then vacuum dry at 40℃ for 12h to obtain the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt.

[0038] (3) 2g of grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer, 0.2g of bisphenol A diglycidyl ether, and 0.002g of 2,4,6-tris(dimethylaminomethyl)phenol were dissolved in tetrahydrofuran and mixed evenly. The solution was then applied to different substrates and crosslinked and cured at 70°C to obtain a grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating.

[0039] Example 3

[0040] (1) First, polyethylene glycol (polyethylene glycol-800) (10 mmol, 8 g) with a molecular weight of 800 and 3-aminopropyltriethoxysilane (4.2 mmol, 0.93 g) were added to a three-necked flask containing dimethyl sulfoxide for dissolution and stirring. Nitrogen gas was introduced and the reaction was carried out at 100 °C for 1 h. Then the temperature was gradually increased to 150 °C and the reaction was continued for 24 h before stopping. The crude product was rotary evaporated at 80 °C to remove unreacted monomers and solvents to obtain a long-chain hyperbranched organosilicon polymer.

[0041] (2) Dissolve 4g of 2,3-epoxypropyltrimethylammonium chloride in 20mL of deionized water, adjust the pH of the solution to between 9 and 10 with 0.01mol / L NaOH solution, then add 2g of long-chain hyperbranched organosilicon polymer and react at 80℃ for 12h before stopping. Wash the crude product three times with a large amount of cold isopropanol, remove the solvent by rotary evaporation, and then vacuum dry at 40℃ for 12h to obtain the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt.

[0042] (3) 2g of grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer, 0.2g of bisphenol A diglycidyl ether, and 0.002g of 2,4,6-tris(dimethylaminomethyl)phenol were dissolved in tetrahydrofuran and mixed evenly. The solution was then applied to different substrates and crosslinked and cured at 70°C to obtain a grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer antifouling coating.

[0043] Comparative Example 1

[0044] (1) First, polyethylene glycol (polyethylene glycol-200) (10 mmol, 2 g) with a molecular weight of 200 and 3-aminopropyltriethoxysilane (4.2 mmol, 0.93 g) were added to a three-necked flask containing dimethyl sulfoxide for dissolution and stirring. Nitrogen gas was introduced and the reaction was carried out at 100 °C for 1 h. Then the temperature was gradually increased to 150 °C and the reaction was continued for 24 h before stopping. The crude product was rotary evaporated at 80 °C to remove unreacted monomers and solvents to obtain a long-chain hyperbranched organosilicon polymer.

[0045] (2) Dissolve 2g of long-chain hyperbranched organosilicon polymer, 0.2g of bisphenol A diglycidyl ether, and 0.002g of 2,4,6-tris(dimethylaminomethyl)phenol in tetrahydrofuran and mix evenly. Then apply the solution to different substrates and crosslink and cure at 70°C to obtain a long-chain hyperbranched organosilicon polymer antifouling coating.

[0046] Comparative Example 2

[0047] (1) First, polyethylene glycol (polyethylene glycol-200) (10 mmol, 2 g) with a molecular weight of 200 and dimethyldiethoxysilane (10 mmol, 1.48 g) were added to a three-necked flask containing dimethyl sulfoxide for dissolution and stirring. Nitrogen gas was introduced and the reaction was carried out at 100 °C for 1 h. Then the temperature was gradually increased to 150 °C and the reaction was continued for 24 h before stopping. The crude product was rotary evaporated at 80 °C to remove unreacted monomers and solvents to obtain a linear organosilicon polymer.

[0048] (2) Dissolve 4g of 2,3-epoxypropyltrimethylammonium chloride in 20mL of deionized water, adjust the pH of the solution to between 9 and 10 with 0.01mol / L NaOH solution, then add 2g of linear organosilicon polymer and react at 80℃ for 12h before stopping. Wash the crude product three times with a large amount of cold isopropanol, remove the solvent by rotary evaporation, and then vacuum dry at 40℃ for 12h to obtain the linear organosilicon polymer grafted with quaternary ammonium salt.

[0049] (3) Dissolve 2g of linear organosilicon polymer, 0.2g of bisphenol A diglycidyl ether, and 0.002g of 2,4,6-tris(dimethylaminomethyl)phenol in tetrahydrofuran and mix evenly. Then apply the solution to different substrates and crosslink and cure at 70°C to obtain a linear organosilicon polymer antifouling coating grafted with quaternary ammonium salt.

[0050] To evaluate the static antifouling performance of the antifouling coating of this invention, a real-sea immersion test was conducted. Referring to GB / T5370-2007 (Antifouling Paint Sample Shallow Sea Immersion Test Method), the antifouling coating system prepared in the examples was immersed in the coastal waters of Qingdao to examine its antifouling performance. Scoring was performed based on the adhesion area of ​​fouling organisms on the sample surface (see Table 1). The scoring rules are as follows: 100 points for no biological adhesion; 95 points for only primary attached organisms such as biofilms; and 95 points for large fouling organisms such as barnacles, calculated using the following formula: 95 - number of individual attachments - coverage area of ​​the group attachment. Simultaneously, the coating slurry obtained in the above examples and comparative examples was uniformly coated onto a glass fiber reinforced epoxy resin board.

[0051] Table 1 shows the static antifouling effects achievable by different coatings.

[0052]

[0053] As can be seen from the data in Examples 1-3 in Table 1, the static antifouling effect of the coating gradually decreases with the increase of polyethylene glycol molecular weight. This is because the long-chain hyperbranched polymer synthesized from polyethylene glycol molecules with smaller molecular weights has a higher density of terminal functional groups, resulting in more quaternary ammonium salt molecules grafted onto it. Therefore, the coating surface has a better bactericidal and antifouling effect. However, as can be seen from Comparative Examples 1-2, the antifouling effect of the coating without quaternary ammonium salt molecules is poor, and the antifouling performance of the linear organosilicon polymer antifouling coating grafted with quaternary ammonium salts is also unsatisfactory. This is because the low density of end groups on the linear polymer results in fewer quaternary ammonium salt molecules distributed on the coating surface. Therefore, Examples 1 and 2 of this invention have better static antifouling effects.

[0054] Furthermore, the mechanical properties of the obtained antifouling coating were evaluated by performing tensile tests on the samples using an electronic tensile testing machine. The samples were cut into dumbbell-shaped strips approximately 75 mm long, 12.5 mm wide, and 4 mm thick. Five groups of samples were tested, and the average value was taken. The results are shown in Table 2.

[0055] Test items Tensile strength (MPa) Elongation at break (%) Example 1 4.45 342 Example 2 6.54 793 Example 3 3.24 934 Comparative Example 1 3.13 278 Comparative Example 2 0.83 145

[0056] As can be seen from the data in Table 2 of Examples 1-3 and Comparative Example 1, the tensile strength of the samples first increases and then decreases with the increase of the molecular weight of the polyethylene glycol used. This is because the molecular chain entanglement between polymers gradually becomes stronger, the brittleness of the samples decreases, and thus the tensile strength increases. However, excessively long-chain polyethylene glycol leads to a lower density of hydroxyl functional groups in the long-chain hyperbranched polymer, resulting in fewer crosslinking sites after reaction with bisphenol A diglycidyl ether, thus leading to a decrease in tensile strength. Long-chain polyethylene glycol molecules can improve the extensibility of the polymer network and the mobility of the polymer chains, so the elongation at break of the samples gradually increases. The results of Comparative Example 2 show that the linear organosilicon polymer has a lower degree of molecular chain entanglement and crosslinking density compared to the long-chain hyperbranched organosilicon polymer, resulting in poorer mechanical properties. Therefore, Example 2 of this invention exhibits a superior static antifouling effect.

[0057] To evaluate the adhesion strength between the antifouling coating of this invention and the substrate, an adhesion test was also conducted. The polymer was dissolved in tetrahydrofuran to prepare a solution of approximately 20 wt%, which was then coated onto a glass fiber reinforced epoxy resin board. The solvent was allowed to evaporate at room temperature, forming a coating approximately 200 μm thick. The board was then left at room temperature for 1–2 days to allow the solvent to fully evaporate. Then, five different areas on the coating surface were selected and aluminum ingots with a diameter of 20 mm were adhered to them using epoxy resin adhesive. Following ASTM D4541, a DeFelsko pull-out tester was used. The adhesion strength of the polymer coating on the glass fiber reinforced epoxy resin board was measured using an AT-A Automatic (AT-A Automatic) method at a pull-out rate of 0.2 MPa·s⁻¹. Finally, the average value of the measurements from five different regions was taken as the result.

[0058] Table 3 shows the adhesion data achievable by different coatings.

[0059] Test items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Adhesion (MPa) 4.4±0.1 5.1±0.2 3.8±0.1 3.2±0.1 1.2±0.2

[0060] As can be seen from the data in Tables 3 (Examples 1-3 and Comparative Example 1), the adhesion between the coating and the substrate first increases and then decreases with the increase of the molecular weight of the polyethylene glycol used. This is because the molecular chain entanglement between polymers gradually strengthens, increasing the cohesive force of the coating and thus increasing the adhesion. However, excessively long-chain polyethylene glycols result in a lower density of terminal functional groups in the long-chain hyperbranched polymers, weakening the hydrogen bond interactions formed between the coating and the substrate, thus leading to a decrease in adhesion. The results of Comparative Example 2 show that the linear organosilicon polymer has a lower degree of molecular chain entanglement and a lower density of terminal functional groups compared to the long-chain hyperbranched organosilicon polymer, resulting in poorer adhesion. Therefore, the adhesion value of Example 2 in this invention is superior.

[0061] The static water contact angle and surface energy of the antifouling coating of this invention were evaluated using a contact angle meter (OCA 25, Dataphysics, Germany). The test method was the solid drop method, with a droplet volume of 3 μL and a drop rate of 1 μL / s. Before measurement, the sample surface was cleaned with nitrogen gas. Then, five different regions were tested on each sample, and the average value was taken to obtain the static water contact angle. Subsequently, the Owens-Wendt-Rabel-Kaelble method was used to calculate the surface free energy of each sample based on the measured contact angles of deionized water (DI) and diiodomethane (DIM). The test results are detailed in Table 4. Table 4 shows the static water contact angle and surface energy data achievable by different coatings.

[0062] Test items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Water contact angle (°) 79 76 72 62 88 Surface energy (mN / m) 22.42 23.72 24.57 26.42 17.41

[0063] As can be seen from the data in Table 4 of Examples 1-3, due to the abundance of hydroxyl-terminal functional groups and a large number of hydrophilic polyethylene glycol segments in the long-chain hyperbranched silicone polymers, all coating surfaces exhibit hydrophilicity. With the increase of the molecular weight of the polyethylene glycol segments, the contact angle of the coating decreases, and the surface energy gradually increases. Data from Comparative Example 1 shows that the coating without grafted quaternary ammonium salt molecules exhibits enhanced hydrophilicity and increased surface energy, which is due to the absence of quaternary ammonium salt molecules at the polymer ends. Data from Comparative Example 2 shows that the linear silicone polymer antifouling coating has weaker hydrophilicity than the long-chain hyperbranched silicone polymer antifouling coating, due to the hydrophilic polyethylene glycol segments and fewer hydroxyl-terminal functional groups. Studies have shown that the surface energy of the coating is better when it is 22-25 mN / m, thus the surface energy values ​​of Examples 1-3 in this invention are superior.

[0064] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt, characterized in that: The antifouling coating is obtained by curing a long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt, a crosslinking agent bisphenol A diglycidyl ether, and a catalyst; the mass ratio of the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt, bisphenol A diglycidyl ether, and the catalyst is 10~100:1:0.01~0.

1. The preparation of the grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer is as follows: Step 1: Dissolve and stir the dihydroxy-terminated long-chain polymer and silane coupling agent in the presence of dimethyl sulfoxide according to the ratio, purge with nitrogen and react at 100 °C for 1 h, then gradually increase the temperature to 150 °C and continue the reaction for 24 h before stopping to obtain the long-chain hyperbranched organosilicon polymer; Step 2: Dissolve excess quaternary ammonium salt in deionized water, control the pH of the solution between 9 and 10, then add the long-chain hyperbranched organosilicon polymer and react at 80-100 °C for 12-24 h, wash the crude product, rotary evaporate and vacuum dry to obtain the grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer; the mass ratio of quaternary ammonium salt to long-chain hyperbranched organosilicon polymer is 1~5:1; The dihydroxy-terminated long-chain polymer is one or more of polyethylene glycol, polypropylene glycol, polytetrahydrofuran, polycaprolactone diol, and dihydroxy-terminated polysiloxane, with a molecular weight between 200 and 2000.

2. The long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt according to claim 1, characterized in that: The catalyst is one or more of 2,4,6-tris(dimethylaminomethyl)phenol, triethanolamine, dimethylethanolamine, boron trifluoride ether, triphenylphosphine, and potassium persulfate.

3. The long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt according to claim 1, characterized in that: The quaternary ammonium salt is one or more of the following: 2,3-epoxypropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride solution, (2-aminoethyl)trimethylammonium chloride hydrochloride, 2,3-dihydroxypropyl-trimethylammonium chloride, (chloromethylene)dimethylammonium chloride, 3-bromopropyltrimethylammonium bromide, 2-bromoethyltrimethylammonium bromide, 2-(4-acetamidophenyl)-N,N,N-trimethylethylammonium bromide, (11-mercaptoundecyl)-N,N,N-trimethylammonium bromide, allyltriethylammonium bromide, 4-methoxy-phenylammonium bromide, and dimethyldiallylammonium chloride.

4. The long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt according to claim 1, characterized in that: The mass ratio of the dihydroxy-terminated long-chain polymer to the silane coupling agent is 1.5~15:

1.

5. The long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt according to claim 4, characterized in that: The silane coupling agent is 3-aminopropyltriethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, hydroxymethyltriethoxysilane, 3-chloropropyltriethoxysilane, 3-bromopropyltriethoxysilane, 3-mercaptopropyltriethoxysilane, 4-chlorophenyltriethoxysilane, 4-(triethoxysilyl)aniline, 4-aminobutyltriethoxysilane, propyltriethoxysilane isocyanate, 5,6-epoxyhexyltriethoxysilane. oxysilanes, 3-thiocyanopropyltriethoxysilane, 3-glycidyl ether oxypropyltriethoxysilane, vinyltrimethoxysilane, chloromethyltrimethoxysilane, allyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 5-bromopentyltrimethoxysilane, p-chlorophenyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-bromopropyltrimethoxysilane, 3-iodopropyltrimethoxysilane, 4-bromobutyltrimethoxysilane Alkane, 6-bromohexyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, m-aminophenyltrimethoxysilane, 11-chloroundecyltrimethoxysilane, acryloyloxypropyltrimethoxysilane, acrylamidepropyltrimethoxysilane, 3-isocyanate-propyltrimethoxysilane, N-aminoethyl-γ-aminopropyltrimethoxysilane, methacryloyloxymethyltrimethoxysilane, 3-(isobutyloxy)propyltrimethoxysilane, One or more of the following: 11-allyloxyundecyltrimethoxysilane, 3-(3-aminophenoxy)propyltrimethoxysilane, 3-(N-allylamino)propyltrimethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, [8-(epoxypropyloxy)-n-octyl]trimethoxysilane, and [3-(6-aminohexylamino)propyl]trimethoxysilane.

6. A method for preparing a long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt as described in claim 1, characterized in that: Step 1: Dissolve and stir the dihydroxy-terminated long-chain polymer and silane coupling agent in dimethyl sulfoxide in a certain proportion, purge with nitrogen and react at 100 °C for 1 h, then gradually increase the temperature to 150 °C and continue the reaction for 24 h before stopping to obtain a long-chain hyperbranched organosilicon polymer; Step 2: Dissolve an excess of quaternary ammonium salt in deionized water, control the pH of the solution between 9 and 10, then add the long-chain hyperbranched organosilicon polymer and react at 80-100 °C for 12-24 h. Wash, rotary evaporate and vacuum dry the crude product to obtain the grafted quaternary ammonium salt long-chain hyperbranched organosilicon polymer; Step 3: Dissolve the long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt, bisphenol A diglycidyl ether, and catalyst in tetrahydrofuran and mix evenly. Then crosslink and cure to obtain an antifouling coating of long-chain hyperbranched organosilicon polymer grafted with quaternary ammonium salt.

7. The application of the long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt as described in claim 1, wherein the long-chain hyperbranched organosilicon polymer antifouling coating grafted with quaternary ammonium salt is used in the field of marine antifouling.

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