A branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide and a preparation method thereof

Abstract

A branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide and a preparation method thereof, the present application relates to the field of polybenzoxazine coating.The present application uses tyrosine polyether amide, primary amine and paraformaldehyde as raw materials, and prepares polybenzoxazine antifouling coating through Mannich reaction and thermal curing.The raw material used in the present application is environment-friendly bio-based compound tyrosine, which has the potential to replace existing petroleum-based raw materials such as phenol and bisphenol A to prepare environment-friendly benzoxazine.The present application introduces amino, long alkyl chain and siloxane bond structures, etc., to endow the coating with excellent antibacterial performance.The coating can maintain long-term antifouling ability.The branched bio-based polybenzoxazine antifouling coating prepared by the present application is used to replace antifouling agent release type and fouling release type coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polybenzoxazine coating, in particular to a branched tyrosine-based bio-based polybenzoxazine antifouling coating and a preparation method thereof. BACKGROUND

[0002] Marine biofouling is a persistent problem in the marine industry, causing serious damage and economic losses to infrastructure equipment in the ocean. Developing effective measures to inhibit marine biofouling and achieve long-term safe operation of marine underwater facilities has important economic and social significance. At present, antifouling coating is the simplest and most effective method to reduce marine fouling, and usually adopts two strategies of antifouling agent release and fouling release to achieve the expected antifouling performance. Antifouling agent release type coating mainly kills microorganisms by releasing antifouling agents, and these substances will accumulate in the marine ecosystem, causing secondary pollution and even forming microplastics, affecting the marine environment. Fouling release type coating is usually based on functional groups with stable structure, and constructs a smooth surface with characteristics such as wettability, low surface energy and low modulus to minimize the adhesion strength of microorganisms, which is a kind of green and environmentally friendly marine antifouling material. However, under long-term use environment, microorganisms can still form large-scale biofilms, eventually leading to the failure of antifouling coating. Therefore, by combining the two antifouling strategies through flexible structural design, an antifouling coating with synergistic effect of bactericidal function and low surface energy can effectively improve the antifouling performance and long-term utilization rate of the coating.

[0003] In order to cope with the two outstanding problems of oil resource shortage and environmental pollution in global development, it is necessary to replace petroleum-based compounds with bio-based compounds. The raw materials of benzoxazine compounds are phenolic compounds, amine compounds and aldehyde compounds, which have very flexible molecular design properties. At present, multifunctional benzoxazine compounds and resins produced from bio-based raw materials have become one of the effective ways to achieve sustainable development. Amino acids in nature are very rich, and are widely used due to their low cost, easy availability and green environmental protection. The tyrosine derivative is used as a phenolic source to prepare a bio-based polybenzoxazine coating with antibacterial and antifouling properties, and the application potential of the coating in the field of marine antifouling is explored. SUMMARY

[0004] The present application solves the technical problem of poor antibacterial and antifouling performance of the existing coating material applied in the marine field.

[0005] A branched tyrosine polyether amide-based bio-based polybenzoxazine antifouling coating, the material of the coating has the structure of:

[0006]

[0007] wherein x+y+z=5-6; R is

[0008] Where r + s + t = 5 to 6, and n is a positive integer.

[0009] The preparation method of the branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide is specifically carried out according to the following steps:

[0010] 1. Stir and mix tyrosine polyether amide, primary amine compounds, aldehyde compounds and solvent until fully dissolved to obtain a mixture;

[0011] 2. The mixture obtained in step 1 is refluxed at a temperature of 80-95℃. After the reaction is completed, the solvent is removed, and the product is washed, purified and vacuum dried to obtain the branched bio-based benzoxazine monomer based on tyrosine polyether amide.

[0012] 3. The monomer obtained in step 2 is subjected to spin coating and thermosetting treatment to obtain the branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide.

[0013] The preparation process of tyrosine polyether amide is as follows:

[0014] Under nitrogen protection, Boc-L-tyrosine (1.120 g) was dissolved in dichloromethane (20 mL), and triethylamine (0.6 mL) and isobutyl chloroformate (0.56 mL) were added in an ice bath. The mixture was then allowed to return to room temperature and reacted for 2 hours. Branched polyetheramine T403 (0.6 mL) was then added to the reaction solution, and the reaction was continued at room temperature for 36 hours. After the reaction was complete, the solution was extracted three times with ethyl acetate to obtain the organic phase, which was then washed three times with saturated sodium bicarbonate aqueous solution and dried over anhydrous magnesium sulfate. A small amount of concentrated hydrochloric acid was then added to the solution to remove the Boc protecting group at room temperature. The solution was then filtered and concentrated to remove the solvent, yielding a yellow viscous product.

[0015] The specific preparation process is as follows:

[0016]

[0017] The general formula for the reaction in this invention is:

[0018]

[0019] This invention utilizes tyrosine polyether amide, a bio-based compound derived from tyrosine, primary amines of varying functionalities, and paraformaldehyde as raw materials to prepare a polybenzoxazine antifouling coating via the Mannich reaction and thermosetting. The raw material used is the environmentally friendly bio-based compound tyrosine, which has the potential to replace existing petroleum-based raw materials such as phenol and bisphenol A in the preparation of environmentally friendly benzoxazine coatings. By introducing amino groups, long alkyl chains, and siloxane bonds, the coating acquires excellent antibacterial properties. Simultaneously, the branched bio-based polybenzoxazine coating based on tyrosine polyether amide exhibits low surface energy and maintains long-lasting antifouling capabilities. Furthermore, the branched bio-based polybenzoxazine coating, utilizing the synergistic effect of its inherent antibacterial properties and fouling-release properties, holds promise as a new strategy to replace antifouling agent-releasing and fouling-releasing coatings.

[0020] The branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide described in this invention possesses inherent antibacterial and fouling release properties, and has broad application prospects in the field of marine antifouling coatings.

[0021] Beneficial effects of this invention:

[0022] (1) Using tyrosine polyether amide as a phenol source, it can replace petroleum-based raw materials such as phenol to synthesize bio-based antibacterial polybenzoxazine coatings, which have the advantages of being green, environmentally friendly and environmentally friendly.

[0023] (2) Taking advantage of the trifunctional phenolic hydroxyl group of tyrosine polyetheramide, it was used as the phenolic source of polybenzoxazine and synthesized A3+B with primary amines of different functionalities. n Branched polybenzoxazine coatings provide new ideas for the application and development of tyrosine in the field of polybenzoxazine;

[0024] (3) The hydrophobic structure of the polybenzoxazine structure, including the cations and long alkyl chains, provides antibacterial properties to the coating. At the same time, based on the low surface energy of the prepared polybenzoxazine coating, the coating is endowed with the characteristics of fouling release, giving full play to the synergistic effect of antibacterial and fouling release properties, and demonstrating the excellent marine antifouling performance of the tyrosine-branched polybenzoxazine coating.

[0025] The branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide prepared in this invention is applied in the field of marine antifouling coatings. Attached Figure Description

[0026] Figure 1 The infrared spectrum of the branched bio-based benzoxazine monomer prepared in Example 2 with amino-terminated polydimethylsiloxane as the amine source;

[0027] Figure 2The 1H NMR spectrum of the branched bio-based benzoxazine monomer prepared in Example 2 with amino-terminated polydimethylsiloxane as the amine source (using deuterated trichloromethane as a reagent);

[0028] Figure 3 The surface water contact angle of the branched bio-based polybenzoxazine antifouling coating prepared in Example 2, which uses amino-terminated polydimethylsiloxane as the amine source;

[0029] Figure 4 The image shows the antibacterial adhesion performance test of the branched bio-based polybenzoxazine antifouling coating prepared in Example 2, which uses amino-terminated polydimethylsiloxane as the amine source.

[0030] Figure 5 The image shows the anti-diatom adhesion performance test results of the branched bio-based polybenzoxazine antifouling coating prepared in Example 2, which uses amino-terminated polydimethylsiloxane as the amine source. Detailed Implementation

[0031] Specific Implementation Method 1: This implementation method provides a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide. The coating material has the following structure:

[0032]

[0033] Where x + y + z = 5 to 6; R is

[0034] Where r + s + t = 5 to 6, and n is a positive integer.

[0035] Specific Implementation Method Two: This implementation method provides a method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide, specifically following these steps:

[0036] 1. Stir and mix tyrosine polyether amide, primary amine compounds, aldehyde compounds and solvent until fully dissolved to obtain a mixture;

[0037] 2. The mixture obtained in step 1 is refluxed at a temperature of 80-95℃. After the reaction is completed, the solvent is removed, and the product is washed, purified and vacuum dried to obtain the branched bio-based benzoxazine monomer based on tyrosine polyether amide.

[0038] 3. The monomer obtained in step 2 is subjected to spin coating and thermosetting treatment to obtain the branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide.

[0039] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the molar ratio of the phenolic hydroxyl group of the tyrosine polyether amide, the amino group of the primary amine compound, and the aldehyde group of the aldehyde compound in step one is 1:1.05:2.1. Everything else is the same as in Specific Implementation Method 2.

[0040] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods Two or Three in that the primary amine compounds mentioned in step one include monofunctional aliphatic amines, furfurylamine, aniline, phenethylamine, tryptamine, difunctional aliphatic amines, amino-terminated polydimethylsiloxane, polyetheramine D230, and polyfunctional polyetheramine T403. Everything else is the same as in Specific Implementation Methods Two or Three.

[0041] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods Two to Four in that the aldehyde compound mentioned in step one is paraformaldehyde or a 37% formaldehyde aqueous solution. Everything else is the same as in Specific Implementation Methods Two to Four.

[0042] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods Two to Five in that the solvent in step one is a mixture of one or more of dioxane, toluene, and xylene, which is then mixed with anhydrous ethanol. Everything else is the same as in Specific Implementation Methods Two to Five.

[0043] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods Two to Six in that: in step one, the aldehyde compound is added in multiple batches. Everything else is the same as in Specific Implementation Methods Two to Six.

[0044] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods Two to Seven in that the temperature during the stirring and mixing process in Step One is controlled at 70°C. Everything else is the same as in Specific Implementation Methods Two to Seven.

[0045] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods Two to Eight in that the washing and purification process in step two involves dissolving the product in dichloromethane, followed by extraction with saturated sodium chloride solution, saturated sodium carbonate solution, and deionized water sequentially, then drying and filtering, and finally purification by recrystallization. Everything else is the same as in Specific Implementation Methods Two to Eight.

[0046] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods Two to Nine in that the heat curing temperature in step three is 100-210℃, and the curing time is 2-14 hours. Everything else is the same as in Specific Implementation Methods Two to Nine.

[0047] The scope of this invention is not limited to the above-described embodiments; a combination of one or more specific embodiments can also achieve the purpose of the invention.

[0048] Example 1:

[0049] A method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide, specifically comprising the following steps:

[0050] 1. Place 2.0 g of tyrosine polyether amide into a reaction flask, add 30 mL of solvent (anhydrous ethanol and toluene mixed in a volume ratio of 1:2), then add 1.9 g of dodecylamine, heat to 70 °C and stir to mix until fully dissolved to obtain a clear solution. Then add 1.5 g of paraformaldehyde in several portions to obtain a mixed solution.

[0051] 2. The mixture obtained in step 1 was heated to 95°C and stirred under reflux for 12 hours. After the reaction was completed, the solvent was removed, and the product was dissolved in dichloromethane. Then, it was extracted sequentially with saturated sodium chloride solution, saturated sodium carbonate solution and deionized water. After drying and filtration, a branched bio-based benzoxazine crude product with dodecylamine as the amine source was obtained. It was then purified by recrystallization and vacuum dried to obtain a branched bio-based benzoxazine monomer with dodecylamine as the amine source, denoted as (a).

[0052] 3. The monomer obtained in step 2 is spin-coated onto the surface of the iron plate to form a coating. Then, it is subjected to heat curing treatment at 120℃, 140℃, 160℃, 180℃ and 200℃ for 2 hours respectively to obtain a branched bio-based polybenzoxazine antifouling coating with dodecylamine as the amine source, which is (a').

[0053] The structural formula of the coating material prepared in this embodiment is:

[0054]

[0055] Example 2:

[0056] A method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide, specifically comprising the following steps:

[0057] 1. Place 2.0 g of tyrosine polyether amide into a reaction flask, add 30 ml of solvent (anhydrous ethanol and toluene mixed in a volume ratio of 1:2), then add 3.0 g of amino-terminated polydimethylsiloxane, heat to 70 °C and stir to mix until fully dissolved to obtain a clear solution. Then add 1.5 g of paraformaldehyde in several portions to obtain a mixed solution.

[0058] 2. The mixture obtained in step 1 was heated to 95°C and stirred under reflux for 12 hours. After the reaction was completed, the solvent was removed, and the product was dissolved in dichloromethane. Then, it was extracted sequentially with saturated sodium chloride solution, saturated sodium carbonate solution, and deionized water. After drying and filtration, a branched bio-based benzoxazine crude product with amino-terminated polydimethylsiloxane as the amine source was obtained. It was then purified by recrystallization and vacuum dried to obtain a branched bio-based benzoxazine monomer with amino-terminated polydimethylsiloxane as the amine source, denoted as (b).

[0059] 3. The monomer obtained in step 2 is spin-coated onto the surface of the iron plate to form a coating. Then, it is subjected to heat curing treatment at 120℃, 140℃, 160℃, 180℃ and 200℃ for 2 hours respectively to obtain a branched bio-based polybenzoxazine antifouling coating with amino-terminated polydimethylsiloxane as the amine source, which is (b').

[0060] The structural formula of the coating material prepared in this embodiment is:

[0061]

[0062] Figure 1 The infrared spectrum of the branched bio-based benzoxazine monomer prepared in Example 2 with amino-terminated polydimethylsiloxane as the amine source;

[0063] Figure 2 The 1H NMR spectrum of the branched bio-based benzoxazine monomer prepared in Example 2 with amino-terminated polydimethylsiloxane as the amine source (using deuterated chloroform as a reagent).

[0064] Example 3:

[0065] A method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide, specifically comprising the following steps:

[0066] 1. Place 2.0 g of tyrosine polyether amide into a reaction flask, add 30 mL of solvent (anhydrous ethanol and toluene mixed in a volume ratio of 1:2), then add 1.4 g of polyetheramine T403, heat to 70 °C and stir to mix until fully dissolved to obtain a clear solution. Then add 1.5 g of paraformaldehyde in several portions to obtain a mixed solution.

[0067] 2. The mixture obtained in step 1 was heated to 95°C and stirred under reflux for 12 hours. After the reaction was completed, the solvent was removed, and the product was dissolved in dichloromethane. Then, it was extracted sequentially with saturated sodium chloride solution, saturated sodium carbonate solution, and deionized water. After drying and filtration, a branched bio-based benzoxazine crude product with polyetheramine T403 as the amine source was obtained. It was then purified by recrystallization and vacuum dried to obtain the branched bio-based benzoxazine monomer with polyetheramine T403 as the amine source, denoted as (c).

[0068] 3. Spin-coating the monomer obtained in step 2 onto the surface of the iron plate to form a coating, and then performing heat curing treatment at 120℃, 140℃, 160℃, 180℃ and 200℃ for 2 hours respectively to obtain a branched bio-based polybenzoxazine antifouling coating with polyetheramine T403 as the amine source, which is (c').

[0069] The structural formula of the coating material prepared in this embodiment is:

[0070]

[0071] Application performance testing

[0072] Shake-bottle method for testing the antibacterial properties of coatings

[0073] Dilute the bacterial suspension with sterile culture medium to approximately 10% bacterial count. 7 -10 8 A concentration of [number] cells / mL was prepared for use. A certain size of branched polybenzoxazine coating was cleaned with deionized water and sterilized by ultraviolet irradiation for 10 minutes. Subsequently, the test coating was placed in the bacterial solution and co-cultured in a constant temperature shaker at 37°C. The bacterial solution containing the uncoated iron plate was used as the control sample. The optical density values ​​of the bacterial solutions were measured and compared to calculate the antibacterial efficiency. As shown in Table 1, the optical density of the bacterial solution of the branched polybenzoxazine coating (b') was much lower than that of the control sample, showing excellent antibacterial performance.

[0074] Table 1

[0075]

[0076] The contact angle of the branched polybenzoxazine coating (b') was tested using water and diiodomethane as test solutions, and the surface energy was obtained. Figure 3 The surface water contact angle of the branched bio-based polybenzoxazine antifouling coating prepared in Example 2, using amino-terminated polydimethylsiloxane as the amine source, was measured. The static water contact angle of the branched polybenzoxazine coating (b') was 139°, and the surface energy was 23.11 mN / m². 3 The coating exhibits good hydrophobic properties.

[0077] Plate count method for testing the antibacterial adhesion properties of coating surfaces

[0078] Dilute the bacterial suspension with sterile culture medium to approximately 10% bacterial count. 7 -10 8 A concentration of [number] bacteria / mL was prepared for use. A certain size of branched polybenzoxazine coating was cleaned with deionized water and sterilized by UV irradiation for 10 minutes. The coating was then placed in bacterial suspension and co-cultured in a 37°C biochemical incubator for 6 hours. Unattached bacteria were then rinsed off with sterile phosphate buffer solution. The coating was then ultrasonically cleaned with a certain volume of phosphate buffer solution to resuspend the adhering bacteria. The solution was diluted, and plate counting was performed on a solid culture medium surface to investigate the antibacterial adhesion performance of the coating surface. A blank iron plate was used as a control sample. Figure 4 As shown, the agar surface of the branched polybenzoxazine coating (b') shows almost no bacterial colony adhesion, indicating that it has excellent antibacterial adhesion properties and can effectively inhibit the formation of biofilms, thus showing potential application as a marine antifouling material.

[0079] Fluorescence microscopy was used to observe the anti-diatom adhesion properties of the coating surface.

[0080] After placing the algal solutions of *Nyctaginosa* and *Diatomata* into sterilized conical flasks and sealing them with an aerobic membrane, the flasks were placed in a light incubator for activation and expansion culture. The light / dark cycle was 12 / 12 hours, and the temperature was 21±2℃. During the culture, the conical flasks were shaken 1-3 times daily. Once the diatoms entered the exponential growth phase, the algal solutions were aliquoted and coated with a branched polybenzoxazine coating (b') for antifouling performance testing. After 7 and 14 days, the coating was removed from the algal solutions, and the unattached diatoms were gently rinsed off with artificial seawater. The number of attached algae was then observed under a fluorescence microscope. Figure 5 As shown in the figure, the control group is a bare, uncoated blank iron plate. It can be seen from the figure that the blank iron plate is covered with a large amount of algae, while the branched polybenzoxazine coating (b') has almost no algae attached, indicating that the coating prepared in this invention has anti-diatom adhesion properties.

Claims

1. A branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide, characterized in that... The material of the coating has the following structure: Where x + y + z = 5 to 6; R is Where r + s + t = 5 to 6, and n is a positive integer.

2. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide as described in claim 1, characterized in that... This method is specifically carried out in the following steps:

1. Stir and mix tyrosine polyether amide, primary amine compounds, aldehyde compounds and solvent until fully dissolved to obtain a mixture; 2. The mixture obtained in step 1 is refluxed at a temperature of 80-95℃. After the reaction is completed, the solvent is removed. Then the product is washed, purified, and vacuum dried to obtain the branched bio-based benzoxazine monomer based on tyrosine polyether amide.

3. The monomer obtained in step 2 is subjected to spin coating and thermosetting treatment to obtain the branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide.

3. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... The molar ratio of the phenolic hydroxyl group of the tyrosine polyether amide, the amino group of the primary amine compound, and the aldehyde group of the aldehyde compound in step one is 1:1.05:2.

1.

4. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... The primary amine compounds mentioned in step one include monofunctional aliphatic amines, furfurylamine, aniline, phenethylamine, tryptamine, difunctional aliphatic amines, amino-terminated polydimethylsiloxane, polyetheramine D230, and polyfunctional polyetheramine T403.

5. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... The aldehyde compound mentioned in step one is paraformaldehyde or a 37% aqueous solution of formaldehyde.

6. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... The solvent mentioned in step one is one or a mixture of several of dioxane, toluene and xylene, which is then mixed with anhydrous ethanol.

7. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... Step one involves adding the aldehyde compound in multiple batches.

8. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... During the stirring and mixing process described in step one, the temperature is controlled at 70℃.

9. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... The washing and purification process described in step two involves dissolving the product in dichloromethane, then extracting it sequentially with saturated sodium chloride solution, saturated sodium carbonate solution, and deionized water, followed by drying and filtration, and then purifying it by recrystallization.

10. The method for preparing a branched bio-based polybenzoxazine antifouling coating based on tyrosine polyether amide according to claim 2, characterized in that... The temperature for heat curing in step three is 100-210℃, and the curing time is 2-14 hours.

Images