Long-chain and short-chain liquid surface carbamate antifouling coating as well as preparation method and application thereof

Abstract

The invention discloses a long-chain and short-chain liquid surface carbamate antifouling coating as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving dodecafluoroheptyl methacrylate, beta-mercaptoethanol and a photoinitiator in a tetrahydrofuran solution to obtain a solution A; then adding the solution A into a three-neck flask, carrying out an ultraviolet light-initiated reaction in a shielding gas environment, and continuously stirring in the process to finally obtain a fluorocopolymer B; then mixing monohydroxyl-terminated polydimethylsiloxane with polypropylene glycol, and removing water to obtain a solution C; and finally, chemically grafting the flexible long chain of the monohydroxyl-blocked polydimethylsiloxane and the flexible short chain of the fluorocopolymer to carbamate. The long-chain and short-chain liquid surface carbamate antifouling coating can be cured at normal temperature, is environment-friendly, inhibits adhesion of fouling organisms, and has good mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of marine antifouling coatings, and in particular to a long- and short-chain liquid surface carbamate antifouling coating and a preparation method and application thereof. Background Art

[0002] Marine biofouling is a well-known problem. In the shortest possible time, the hulls of ships and other artificial underwater surfaces are inevitably occupied by various marine organisms. Marine biofouling has caused serious economic and environmental problems. It is crucial to effectively control biofouling. Currently, antifouling coatings are an effective means to inhibit biofouling. Among antifouling coatings, a smooth liquid-injected surface is a very typical antifouling coating, but the lubricant in the coating is easily exhausted; when a large area is damaged, the coating will lose a large amount of lubricant and lose its performance. Therefore, it is necessary to develop an antifouling coating preparation technology that does not release lubricants but has a lubricant-like surface, which can be coated on the surface of underwater equipment such as ships, water work platforms, underwater vehicles, etc., to inhibit biofouling.

[0003] The applicant disclosed a polyurethane antifouling coating based on oxime-carbamate bond and its preparation method in CN117089276A, wherein the preparation method comprises the following steps: S1. After removing water from the polyether diol, mix it evenly with diisocyanate, heat it to 70-80°C, and react to obtain polymer A; S2. Weigh polymer A, solvent, dioxime and dibutyltin dilaurate catalyst, mix them evenly, and react to obtain polymer B; S3. Coat polymer B on a substrate to make a sample, place the prepared sample at room temperature, and then heat it to 60°C to cure to obtain a coating. The antifouling coating of the invention has good wear resistance. The coating can undergo hydrolysis reaction with seawater based on the oxime-carbamate bond, which can meet the requirements of the coating being resistant to washing and can solve the problem of marine organisms attaching to the surface of the hull to cause invasion of alien species. The antifouling coating is heated to 60°C and cured, and the dioxime with antifouling properties is released to further inhibit the attachment of fouling organisms, which is different from the concept of the present invention. Summary of the invention

[0004] In view of this, the purpose of the present invention is to propose a long- and short-chain liquid surface carbamate antifouling coating and its preparation method and application. The long- and short-chain liquid surface carbamate antifouling coating can be cured at room temperature, is environmentally friendly, can inhibit the adhesion of fouling organisms, and has good mechanical properties.

[0005] The technical solutions adopted are:

[0006] 1. A method for preparing a long- and short-chain liquid surface carbamate antifouling coating, characterized in that it comprises the following steps:

[0007] S1. dissolving dodecafluoroheptyl methacrylate, β-mercaptoethanol and a photoinitiator in a tetrahydrofuran solution to obtain a solution A;

[0008] S2. Solution A was added to a three-necked flask, and a UV-initiated reaction was carried out in a protective gas environment, with continuous stirring during the process, to finally obtain a fluorinated copolymer B;

[0009] S3. The monohydroxy-terminated polydimethylsiloxane and polypropylene glycol are mixed and dehydrated to obtain a solution C;

[0010] S4. dissolving hexamethylene diisocyanate trimer in a mixed solution of xylene and tetrahydrofuran to obtain a solution D;

[0011] S5. Add B to C at room temperature, and then slowly drip D into C at room temperature, stirring continuously;

[0012] S6. After the addition is completed, the reaction is heated to 80-85°C and stirred continuously to ensure sufficient reaction, and finally a prepolymer E is obtained;

[0013] S7. Add a curing agent polyaspartic acid ester, a leveling agent, and a defoaming agent to E, and stir to obtain a solution F;

[0014] S8. Apply F to the surface of the substrate and cure it at room temperature for 2 hours to obtain a long- and short-chain liquid-phase surface urethane antifouling coating.

[0015] 2. The method for preparing a long- and short-chain liquid surface carbamate antifouling coating according to claim 1, characterized in that, in S1, the mass ratio of dodecafluoroheptyl methacrylate and β-mercaptoethanol is 400:39; the mass of the photoinitiator is 3%-5% of the total mass of dodecafluoroheptyl methacrylate and β-mercaptoethanol; and the mass of tetrahydrofuran does not exceed 30% of the total mass.

[0016] 3. The method for preparing a long- and short-chain liquid surface urethane antifouling coating according to claim 1 is characterized in that the molar ratio of the fluorine copolymer B in S2, the hexamethylene diisocyanate trimer in S4, and the monohydroxy-terminated polydimethylsiloxane and polypropylene glycol in S3 is 0.1-0.5:1:0.3:0.25.

[0017] 4. The method for preparing a long- and short-chain liquid surface carbamate antifouling coating according to claim 1 is characterized in that the mass ratio of xylene and tetrahydrofuran in S4 is 1:1, and the total amount of xylene and tetrahydrofuran is 30%-50% of the total mass of the fluoro copolymer B in S2, the solution C in S3 and the hexamethylene diisocyanate trimer in S4.

[0018] 5. The method for preparing a long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that the mass of the defoamer and the leveling agent in S7 is 0.1% of the total mass of the S6 prepolymer and the S7 polyaspartic acid ester, respectively.

[0019] 6. The method for preparing a long- and short-chain liquid surface carbamate antifouling coating according to claim 1, characterized in that in S3, water is removed at 100-110°C for 2-3 hours.

[0020] 7. The method for preparing a long- and short-chain liquid surface carbamate antifouling coating according to claim 1, characterized in that in S5, the dropping speed is 50-150 g / h, and the dropping lasts for 30-40 minutes.

[0021] 8. The method for preparing a long- and short-chain liquid surface carbamate antifouling coating according to claim 1, characterized in that in S7, stirring at 2000-2500 rpm for 5-10 minutes obtains solution F.

[0022] In the present invention, the leveling agent and the defoaming agent can be selected from commercially available leveling agents and defoaming agents, including but not limited to, for example, the leveling agent is selected from one of the commercially available German BYK BYK-306, BYK-307, BYK-330, and the defoaming agent is selected from one of the commercially available German BYK BY066N, BYK-141, BYK-071, BYK-060N.

[0023] The liquid-phase functional urethane antifouling coating of the present invention is prepared by the above-mentioned preparation method.

[0024] The liquid-phase functional urethane antifouling coating prepared by the preparation method is used in the surface protection of underwater equipment including ships, water work platforms, underwater vehicles, etc. That is, the prepared antifouling coating can be coated on the surface of underwater equipment such as ships, water work platforms, underwater vehicles, etc., to inhibit biofouling.

[0025] In the above technical solution,

[0026] The present invention is an antifouling coating that chemically grafts flexible monohydroxyl-terminated polydimethylsiloxane long chains and hydroxyl fluorine copolymer short chains onto carbamate. A large number of repeated CF bonds and Si-O bonds can keep the molecular chain flexible at low temperatures, and the grafted monohydroxyl-terminated polydimethylsiloxane flexible long chains and hydroxyl fluorine copolymer flexible short chains have liquid-like smooth properties. The flexible chains grafted on the surface have a very high migration rate, and the adhesion of biological fouling can be inhibited through the rapid disturbance of the flexible chains; and the performance of inhibiting the adhesion of biological fouling is enhanced by introducing a polydimethylsiloxane / fluorine copolymer double-layer protective structure.

[0027] Wherein: the structural formula of (a) monohydroxy-terminated polydimethylsiloxane and (b) hydroxy fluorine copolymer is as follows:

[0028] (a)

[0029] (b)

[0030] In (a), n is the degree of polymerization, usually 10-1000, and R is methyl or ethyl.

[0031] In (b), a is the degree of polymerization, usually 10-1000.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention introduces environmentally friendly polydimethylsiloxane / fluorine copolymer flexible chains into the field of polyurethane antifouling coatings, which has certain application prospects. The coating achieves double-layer protection by grafting flexible chain segments with different molecular weights, which improves the antifouling performance of the coating, and the coating is environmentally friendly.

[0034] 2. The antifouling coating of the present invention is chemically grafted onto carbamate with monohydroxyl-terminated polydimethylsiloxane flexible long chains and fluoro copolymer flexible short chains, so that the coating has liquid-like smooth properties. The flexible chains grafted on the surface have a very high migration rate, and the adhesion of biological fouling can be inhibited by the rapid disturbance of the flexible chains. The monohydroxyl-terminated polydimethylsiloxane flexible chains and fluoro copolymer flexible chains are used to achieve low surface energy smoothness, thereby inhibiting the adhesion of fouling organisms. Controlling the content of monohydroxyl-terminated polydimethylsiloxane and fluoro copolymer chains and hexamethylene diisocyanate trimer can control the antifouling properties of the coating.

[0035] 3. The fluorine copolymer flexible chain has more hydrogen bonds, and the presence of hydrogen bonds in the fluorine copolymer can improve the mechanical properties of the coating. The mechanical properties of the coating can be controlled by adjusting the content of the fluorine copolymer flexible chain.

[0036] 4. The polymer resin (solution F) has good compatibility with the solvent and can be stored for a long time without deterioration or solidification, which is convenient for subsequent application of marine antifouling coatings or compounding into marine antifouling coatings.

[0037] 5. The polymer resin (Solution F) can be cured at room temperature for two hours. DETAILED DESCRIPTION

[0038] The present invention is described in detail below through specific examples, but the use and purpose of these exemplary implementation modes are only used to illustrate the present invention, and do not constitute any form of limitation on the actual protection scope of the present invention, nor limit the protection scope of the present invention to them.

[0039] Example 1

[0040] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0041] (1) 8 g of dodecafluoroheptyl methacrylate, 0.78 g of β-mercaptoethanol, 0.44 g of a photoinitiator and 2.77 g of tetrahydrofuran were added to a three-necked flask, nitrogen was continuously introduced, the solution was ultraviolet initiated, and stirring was continued at a speed of 400 rpm to obtain a fluorine copolymer.

[0042] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG (i.e., polypropylene glycol) were added to a three-necked flask and vacuum-dried at 110° C. for 2 hours.

[0043] (3) 11.99 g of fluorine copolymer was added to a three-necked flask, 60 g of hexamethylene diisocyanate trimer was dissolved in 27.9 g of xylene and 27.9 g of tetrahydrofuran, and the solution was slowly added dropwise to the three-necked flask at room temperature for 30 minutes with continuous stirring at a speed of 400 rpm.

[0044] (4) After the addition is completed, the reaction is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction, and finally a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0045] (5) Take 20 g of prepolymer, add 7.98 g of curing agent polyaspartic acid ester, 0.028 g of leveling agent, and 0.028 g of defoaming agent, and stir at 2000 rpm for five minutes.

[0046] (6) The resin was coated on the surface of the substrate and cured at room temperature for 2 hours to finally obtain a liquid-like functional polyurethane antifouling coating, which was named PFNP-10.

[0047] Do the following experiment:

[0048] 1. Laboratory static inhibition and desorption of diatoms: The sample of Example 1 was evenly smeared on a glass sheet with a size of 2.5 cm × 3.5 cm, and a blank glass sheet was selected as a blank control. The sample sheet and the blank glass sheet were immersed in two model algae species (Dinocampus glomerulosa and Nitzschia closterii) for 1 day, 3 days and 5 days respectively. After taking out the samples, the unattached algae were removed, and the algae attachment on the coating was photographed under an optical microscope. Five areas of each coating were randomly selected for photography, and the average number of diatom cells on the blank glass sheet and the sample of Example 1 was calculated by the following formula (1):

[0049]

[0050] Where K is the inhibition rate of diatom attachment, NB is the average number of diatom cells on the surface of the blank glass sheet, and N1 is the average number of diatom cells on the surface of the sample.

[0051] 2. Mechanical properties experiment: The coating was stretched and elongated at break using a universal testing machine. The test stretching speed was 25 mm / min, and three samples were tested in parallel.

[0052] The inhibition rate of A. diffusa after 5 days was calculated to be 59.67%, and the maximum breaking strength and breaking elongation were 2.87 MPa and 119.04%.

[0053] Example 2

[0054] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0055] (1) 16 g of dodecafluoroheptyl methacrylate, 1.56 g of β-mercaptoethanol, 0.88 g of a photoinitiator and 5.54 g of tetrahydrofuran were added to a three-necked flask, nitrogen was continuously introduced, the solution was ultraviolet initiated, and stirring was continued at a speed of 400 rpm to obtain a fluorinated copolymer.

[0056] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110° C. for 2 hours.

[0057] (3) 23.98 g of fluorine copolymer was added to a three-necked flask, 60 g of hexamethylene diisocyanate trimer was dissolved in 30.3 g of xylene and 30.3 g of tetrahydrofuran, and the solution was slowly added dropwise to the three-necked flask at room temperature for 30 minutes with continuous stirring at a speed of 400 rpm.

[0058] (4) After the addition is completed, the reaction is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction, and finally a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0059] (5) Take 20 g of prepolymer, add 7.27 g of curing agent polyaspartic acid ester, 0.027 g of leveling agent, and 0.027 g of defoaming agent, and stir at 2000 rpm for five minutes.

[0060] (6) The resin was coated on the surface of the substrate and cured at room temperature for 2 hours to finally obtain a liquid-like functional polyurethane antifouling coating, which was named PFNP-20.

[0061] The inhibition rate of A. diffusa after 5 days was calculated to be 72.54%, and the maximum breaking strength and breaking elongation were 3.74 MPa and 267.83%.

[0062] Example 3

[0063] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0064] (1) 24 g of dodecafluoroheptyl methacrylate, 2.34 g of β-mercaptoethanol, 1.32 g of a photoinitiator and 8.31 g of tetrahydrofuran were added to a three-necked flask, nitrogen was continuously introduced, the solution was ultraviolet initiated, and stirring was continued at a speed of 400 rpm to obtain a fluorine copolymer.

[0065] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110° C. for 2 hours.

[0066] (3) 35.97 g of fluorine copolymer was added to a three-necked flask, 60 g of hexamethylene diisocyanate trimer was dissolved in 32.7 g of xylene and 32.7 g of tetrahydrofuran, and the solution was slowly added dropwise to the three-necked flask at room temperature for 30 minutes with continuous stirring at a speed of 400 rpm.

[0067] (4) After the addition is completed, the reaction is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction, and finally a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0068] (5) Take 20 g of the prepolymer, add 6.27 g of curing agent polyaspartic acid ester, 0.026 g of leveling agent, and 0.026 g of defoaming agent, and stir at 2000 rpm for five minutes.

[0069] (6) The resin was applied to the surface of the substrate and cured at room temperature for 2 hours to finally obtain a liquid-like functional polyurethane antifouling coating, which was named PFNP-30.

[0070] The inhibition rate of Ampelopsis pilosa was calculated to be 79.16% after 5 days, and the maximum breaking strength and breaking elongation were 4.55 MPa and 275.76%.

[0071] Example 4

[0072] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0073] (1) 32 g of dodecafluoroheptyl methacrylate, 3.12 g of β-mercaptoethanol, 1.76 g of a photoinitiator and 11.08 g of tetrahydrofuran were added to a three-necked flask, nitrogen was continuously introduced, the solution was ultraviolet initiated, and stirring was continued at a speed of 400 rpm to obtain a fluorine copolymer.

[0074] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110° C. for 2 hours.

[0075] (3) 47.96 g of fluorine copolymer was added to a three-necked flask, 60 g of hexamethylene diisocyanate trimer was dissolved in 35.11 g of xylene and 35.11 g of tetrahydrofuran, and the solution was slowly added dropwise to the three-necked flask at room temperature for 30 minutes with continuous stirring at a speed of 400 rpm.

[0076] (4) After the addition is completed, the reaction is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction, and finally a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0077] (5) Take 20 g of prepolymer, add 5.55 g of curing agent polyaspartic acid ester, 0.025 g of leveling agent, and 0.037 g of defoaming agent, and stir at 2000 rpm for five minutes.

[0078] (6) The resin was coated on the surface of the substrate and cured at room temperature for 2 hours to finally obtain a liquid-like functional polyurethane antifouling coating, which was named PFNP-40.

[0079] The inhibition rate of A. diffusa after 5 days was calculated to be 88.52%, and the maximum breaking strength and breaking elongation were 6.4 MPa and 356.8%.

[0080] Example 5

[0081] The long- and short-chain liquid surface carbamate antifouling coating of this embodiment is prepared by the following steps:

[0082] (1) 8 g of dodecafluoroheptyl methacrylate, 0.78 g of β-mercaptoethanol, 0.44 g of a photoinitiator and 2.77 g of tetrahydrofuran were added to a three-necked flask, nitrogen was continuously introduced, the solution was ultraviolet initiated, and stirring was continued at a speed of 400 rpm to obtain a fluorine copolymer.

[0083] (2) 42.6 g of monohydroxy-terminated polydimethylsiloxane and 25 g of PPG were added to a three-necked flask and vacuum-dried at 110° C. for 2 hours.

[0084] (3) 11.99 g of fluorine copolymer was added to a three-necked flask, 60 g of hexamethylene diisocyanate trimer was dissolved in 27.9 g of xylene and 27.9 g of tetrahydrofuran, and the solution was slowly added dropwise to the three-necked flask at room temperature for 30 minutes with continuous stirring at a speed of 400 rpm.

[0085] (4) After the addition is completed, the reaction is heated to 80-85°C and stirred for 3 hours to ensure sufficient reaction, and finally a prepolymer is obtained for the subsequent synthesis of antifouling coatings.

[0086] (5) Take 20 g of prepolymer, add 4.92 g of curing agent polyaspartic acid ester, 0.024 g of leveling agent, and 0.037 g of defoaming agent, and stir at 2000 rpm for five minutes.

[0087] (6) The resin was applied to the surface of the substrate and cured at room temperature for 2 hours to finally obtain a liquid-like functional polyurethane antifouling coating, which was named PFNP-50.

[0088] The inhibition rate of A. diffusa after 5 days was calculated to be 92.19%, and the maximum breaking strength and breaking elongation were 5.52 MPa and 300.06%.

[0089] The series of detailed descriptions listed above are only specific descriptions of feasible embodiments of the present invention. They are not intended to limit the scope of protection of the present invention. All equivalent embodiments or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a long- and short-chain liquid surface carbamate antifouling coating, characterized in that: The steps include: S1. dissolving dodecafluoroheptyl methacrylate, β-mercaptoethanol and a photoinitiator in a tetrahydrofuran solution to obtain a solution A; S2. Solution A was added to a three-necked flask, and a UV-initiated reaction was carried out in a protective gas environment, with continuous stirring during the process, to obtain a fluorinated copolymer B; S3. The monohydroxy-terminated polydimethylsiloxane and polypropylene glycol are mixed and dehydrated to obtain a solution C; S4. dissolving hexamethylene diisocyanate trimer in a mixed solution of xylene and tetrahydrofuran to obtain a solution D; S5. Add B to C at room temperature, and then slowly drip D into C at room temperature, stirring continuously; S6. After the addition is completed, the reaction is heated to 80-85°C and stirred continuously to ensure sufficient reaction, and finally the prepolymer E is obtained; S7. Add a curing agent polyaspartic acid ester, a leveling agent, and a defoaming agent to E, and stir to obtain a solution F; S8. Apply F to the surface of the substrate and cure it at room temperature for 2 hours to obtain a long- and short-chain liquid-phase surface urethane antifouling coating.

2. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S1, the mass ratio of dodecafluoroheptyl methacrylate to β-mercaptoethanol is 400:39; the mass of the photoinitiator is 3%-5% of the total mass of dodecafluoroheptyl methacrylate and β-mercaptoethanol; and the mass of tetrahydrofuran does not exceed 30% of the total mass.

3. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: The molar ratio of the fluorine copolymer B in S2, the hexamethylene diisocyanate trimer in S4, and the monohydroxy-terminated polydimethylsiloxane and polypropylene glycol in S3 is 0.1-0.5:1:0.3:0.

25.

4. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: The mass ratio of xylene to tetrahydrofuran in S4 is 1:1, and the total amount of xylene and tetrahydrofuran is 30%-50% of the total mass of the fluorine copolymer B in S2, the solution C in S3 and the hexamethylene diisocyanate trimer in S4.

5. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: The mass of the defoamer and leveling agent in S7 is 0.1% of the total mass of the S6 prepolymer and S7 polyaspartic acid ester, respectively.

6. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S3, water is removed at 100-110°C for 2-3 hours.

7. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S5, the dropping speed is 50-150 g / h, and the dropping is continued for 30-40 minutes.

8. The method for preparing the long- and short-chain liquid surface urethane antifouling coating according to claim 1, characterized in that: In S7, the mixture was stirred at 2000-2500 rpm for 5-10 minutes to obtain a solution F.

9. A long- and short-chain liquid surface urethane antifouling coating, characterized in that: The invention is prepared by the preparation method described in any one of claims 1 to 8.

10. Application of the long- and short-chain liquid surface carbamate antifouling coating prepared by the preparation method according to any one of claims 1 to 8 in the surface protection of underwater equipment including ships, water work platforms, and underwater vehicles.

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