A polyurethane coating containing eugenol side groups, its preparation method and application

Abstract

The present invention discloses an eugenol side group-containing polyurethane coating, a preparation method thereof and an application. The preparation method comprises the following steps: reacting an aliphatic lactone, a diol and a first catalyst to obtain an aliphatic polyester diol; reacting eugenol, a mercapto alcohol compound and a photoinitiator to obtain an eugenol polyol; dissolving the aliphatic polyester diol, the eugenol polyol, a diisocyanate, a chain extender and a second catalyst in a first solvent for reaction, and after the reaction is completed, dropping the reaction product into a second solvent to obtain the eugenol side group-containing polyurethane, and dissolving the obtained product in a third solvent, and obtaining the coating by a solution casting method. The eugenol side group-containing polyurethane coating obtained by the present invention has rapid and controllable degradability and excellent static antifouling performance. The mass loss after being immersed in seawater for 60 days is increased by 43%, the degradation rate is significantly improved, and no harmful substances are released into the environment, and it has good application potential in the field of marine antifouling coatings.

Description

Technical Field

[0001] The present invention relates to the technical field of marine antifouling materials, and particularly to an eugenol side group-containing polyurethane coating, a preparation method thereof, and an application thereof. Background Art

[0002] Marine biofouling refers to the process in which marine organisms attach and grow on the surface of underwater facilities and structures (such as ship hulls, drilling platforms, and marine sensors, etc.) starting from the moment they enter seawater. The attachment of fouling organisms will increase the hydrodynamic resistance, resulting in a decrease in the traveling speed and maneuverability of ships and an increase in fuel consumption, imposing a huge economic burden on the marine industry. Antifouling coatings are one of the most effective strategies to resist marine biofouling. Currently, commercial antifouling coatings mainly consist of (meth)acrylic polymers and antifouling agents, and their antifouling effect mainly depends on the stable release of the antifouling agents. However, the release of commonly used antifouling agents such as cuprous oxide and fungicides has posed a long-term and serious threat to the marine ecosystem. On the other hand, the problem of marine microplastics caused by the non-degradability of (meth)acrylic polymers has also raised concerns. In recent years, the research and development of antifouling coatings without a toxic substance release mechanism has become the current research trend.

[0003] Biodegradable polymers can be degraded through the enzymatic action of microorganisms such as bacteria, fungi, and algae and chemical hydrolysis, providing an effective solution to the marine microplastic pollution caused by commercial antifouling coatings. Biodegradable antifouling coatings have two advantages: one is that their degradation products have a small molecular weight and will not cause marine microplastic pollution; the other is that on the surface of the coating in a static state, "dynamic antifouling surfaces" can be continuously formed through hydrolysis or enzymatic hydrolysis, thereby effectively inhibiting the attachment of fouling organisms. Generally speaking, the faster the degradation rate of biodegradable polymers, the stronger their antifouling ability. In recent years, polyurethane antifouling coatings containing structural units of polycaprolactone (PCL), poly(lactic acid) (PLA), and poly(lactide-co-glycolide) (PLGA) have shown good application prospects. However, such polyurethane coatings generally have the problem of insufficient antifouling performance caused by a decrease in the later degradation rate. To address this problem, in existing research, antifouling agents such as 4,5-dichloro-2-n-octyl-4-isothiazol-3-one (DCOIT) and butenolide are incorporated into biodegradable polyurethanes to overcome this problem. However, this will bring about the problem of the release of toxic antifouling agents. Therefore, the research and development of a polyurethane-based coating with a controllable degradation rate, excellent antifouling performance, and no release of harmful substances is a current challenge. Summary of the Invention

[0004] Objective of the Invention: The technical problem to be solved by the present invention is to provide a preparation method of a polyurethane coating containing eugenol side groups in view of the deficiencies of the prior art. This coating has rapid and controllable degradability and excellent static antifouling performance, and does not release harmful substances into the environment.

[0005] To achieve the above objective, the technical solution of the present invention is as follows:

[0006] A preparation method of a polyurethane coating containing eugenol side groups, comprising the following steps:

[0007] (1) Under vacuum conditions, an aliphatic lactone, a diol, and a first catalyst are subjected to ring-opening polymerization to obtain an aliphatic polyester diol.

[0008] (2) Under an inert gas atmosphere and ultraviolet light conditions, eugenol, a mercapto alcohol compound, and a photoinitiator are subjected to a thiol-ene click reaction to obtain eugenol polyol.

[0009] (3) Under an inert gas atmosphere, the aliphatic polyester diol, the eugenol polyol, a diisocyanate, a chain extender, and a second catalyst are dissolved in a first solvent for polycondensation reaction. After the reaction is completed, it is dropped into a second solvent to obtain a polyurethane containing eugenol side groups.

[0010] (4) The polyurethane containing eugenol side groups is dissolved in a third solvent and coated on a substrate by a solution casting method, washed with water after drying, and then dried to obtain a polyurethane coating containing eugenol side groups.

[0011] Among them, in step (1), the aliphatic lactone is any one or a combination of lactide, glycolide, or caprolactone; the diol is any one or a combination of ethylene glycol, propylene glycol, 1,4-butanediol, or glycerol; the first catalyst is any one or a combination of stannous octoate or stannous chloride dihydrate. Preferably, the aliphatic lactone is a combination of lactide and glycolide; the diol is any one or a combination of ethylene glycol or propylene glycol; the first catalyst is stannous octoate.

[0012] Among them, in step (1), the molar ratio of the diol to the aliphatic lactone in the feed is 1:5 to 1:10; the dosage of the first catalyst is 0.1 wt‰ to 0.3 wt‰, and the dosage of the first catalyst is 0.1 wt‰ to 0.3 wt‰ of the total weight of the diol and the aliphatic lactone. Preferably, the molar ratio of the diol to the aliphatic lactone in the feed is 1:5 to 1:7; the dosage of the first catalyst is 0.2 wt‰ to 0.3 wt‰. More preferably, the molar ratio of the diol to the aliphatic lactone in the feed is 1:5; the dosage of the first catalyst is 0.3 wt‰.

[0013] Among them, in step (1), for the ring-opening polymerization reaction, the reaction time is 0.5 - 1.5 h, and the reaction temperature is 160 - 180 °C. Preferably, for the ring-opening polymerization reaction, the reaction time is 45 min and the reaction temperature is 160 °C.

[0014] Among them, in step (2), the mercapto alcohol compound is any one or a combination of more than one of 3-mercapto-1,2-propanediol, 1,4-dithiothreitol, or 1,4-dimercapto-2,3-butanediol; the photoinitiator is any one or a combination of more than one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, isopropylthioxanthone, or 2,4-diethylthiazolium ketone. Preferably, the mercapto alcohol compound is any one of 3-mercapto-1,2-propanediol or 1,4-dithiothreitol; the photoinitiator is any one of 2-hydroxy-2-methyl-1-phenyl-1-propanone or isopropylthioxanthone, where the isopropylthioxanthone is a mixture of 2,4 isomers of isopropylthioxanthone.

[0015] Among them, in step (2), the molar ratio of eugenol to 3-mercapto-1,2-propanediol in the feed is 1:1; the addition amount of the photoinitiator is 0.5 wt% - 3.0 wt% of the total weight of eugenol and the mercapto alcohol compound; for the thiol-ene click reaction, the reaction time is 3.0 - 5.0 h. Preferably, the addition amount of the photoinitiator is 2.0 wt% - 3.0 wt% of the total weight of eugenol and the mercapto alcohol compound; for the thiol-ene click reaction, the reaction time is 3.5 h - 5.0 h. More preferably, the addition amount of the photoinitiator is 2.0 wt% of the total weight of eugenol and the mercapto alcohol compound; for the thiol-ene click reaction, the reaction time is 3.5 h.

[0016] Among them, in step (3), the diisocyanate is any one or a combination of isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, lysine diisocyanate or dicyclohexylmethane diisocyanate; the chain extender is any one or a combination of 1,4-butanediol, 1,6-hexanediol or diethylene glycol; the second catalyst is any one or a combination of dibutyltin dilaurate or stannous octoate; the first solvent is any one or a combination of tetrahydrofuran, dichloromethane or acetone; the second solvent is any one or a combination of n-hexane or petroleum ether. Preferably, the diisocyanate is any one or a combination of isophorone diisocyanate or lysine diisocyanate; the chain extender is any one or a combination of 1,4-butanediol or glycol; the second catalyst is any one of dibutyltin dilaurate or stannous octoate; the first solvent is any one of tetrahydrofuran or dichloromethane; the second solvent is any one of n-hexane or petroleum ether.

[0017] Among them, in step (3), the molar ratio of the aliphatic polyester diol, eugenol polyol, diisocyanate, and chain extender fed is 6.67:3.67 - 11.00:27.50 - 33.93:9.83 - 27.26. Preferably, the molar ratio of the aliphatic polyester diol, eugenol polyol, diisocyanate, and chain extender fed is 6.67:11.00:27.50:9.83.

[0018] The dosage of the second catalyst is 1 wt‰ - 5 wt‰; the dosage of the second catalyst is 1 wt‰ - 5 wt‰ of the total weight of the aliphatic polyester diol and eugenol polyol. Preferably, the dosage of the second catalyst is 2 wt‰ - 3 wt‰.

[0019] The volume of the first solvent is calculated based on adding a total weight of 20 - 50 g of the aliphatic polyester diol and eugenol polyol per 100 mL of the first solvent; the volume ratio of the second solvent to the first solvent is 5:1 - 10:1. Preferably, the volume of the first solvent is calculated based on adding a total weight of 20 - 30 g of the aliphatic polyester diol and eugenol polyol per 100 mL of the first solvent; the volume ratio of the second solvent to the first solvent is 5:1 - 7.5:1.

[0020] For the polycondensation reaction, the reaction temperature is 70 - 80 °C, and the reaction time is 3 - 8 h. Preferably, the reaction temperature is 80 °C, and the reaction time is 4.5 - 5 h.

[0021] Among them, in step (3), after the polycondensation reaction is completed, it is dropped into the second solvent to produce a pale yellow viscous substance, which is the eugenol-side-group-containing polyurethane.

[0022] Among them, in step (4), the third solvent is any one or a combination of more than one of tetrahydrofuran, dichloromethane or acetone. Preferably, it is any one of tetrahydrofuran or acetone.

[0023] The volume of the third solvent is based on 10 - 30 g of eugenol-side-group-containing polyurethane dissolved in every 100 mL of the third solvent. Preferably, 15 - 20 g of eugenol-side-group-containing polyurethane is dissolved in every 100 mL of the third solvent.

[0024] Among them, in step (4), the water washing is preferably until there is no impurity residue on the surface. The drying is preferably natural drying.

[0025] The second aspect of the present invention is to provide an eugenol-side-group-containing polyurethane coating prepared by the above preparation method.

[0026] The third aspect of the present invention is to provide the application of the above eugenol-side-group-containing polyurethane coating in water body antifouling. Among them, the water body is preferably the ocean.

[0027] Among them, the antifouling means that the above eugenol-side-group-containing polyurethane coating can inhibit the attachment of diatoms and / or bacteria on the surfaces of ships and other underwater components.

[0028] The eugenol-side-group-containing polyurethane coating can also significantly improve the degradation rate of the coating.

[0029] Beneficial effects:

[0030] The present invention realizes a fast and controllable degradation rate and excellent static antifouling performance by preparing a polyurethane coating with eugenol side groups. This effect is mainly due to the dual functions of the phenoxy anion dissociated from eugenol: First, it synergistically acts with the hydroxide ions in seawater to promote the hydrolysis of the ester bonds of the degradable polyester in the polyurethane, thereby increasing the degradation rate and forming a "dynamic surface" with the release of fouling organisms; Second, the phenoxy anion can form chemical bonds with the active sites of membrane proteins on the cell membrane, destroying the structure and function of the cell membrane, thereby inhibiting the attachment of diatoms and bacteria on the coating and further enhancing the static antifouling effect. The polyurethane coating with eugenol side groups of the present invention not only meets the requirements of marine static antifouling, but also can reduce the risk of marine microplastic pollution.

[0031] (1) The eugenol-side-group-containing polyurethane coating prepared by the present invention has fast and controllable degradability and excellent static antifouling performance, and does not release harmful substances into the environment.

[0032] (2) The eugenol used in the present invention is derived from bio-based sources and belongs to renewable resources.

[0033] (3) The polyurethane coating containing eugenol side groups prepared in the present invention has degradability, avoiding the problem of marine microplastic pollution. The mass loss of the polyurethane coating containing eugenol side groups prepared in the present invention can reach 18.34 mg / cm 2 in 60 days, which is 43% higher than that of the polyurethane coating without eugenol side groups, and the degradation rate is significantly improved.

[0034] (4) The preparation method of the polyurethane coating containing eugenol side groups prepared in the present invention is simple, the raw materials are widely available, it is suitable for industrial production, and it has good application prospects in the field of marine antifouling coatings. Description of the Drawings

[0035] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of the polyurethane containing eugenol side groups prepared in Example 1.

[0036] Figure 2 is a comparison chart of the inhibitory effects of the polyurethane coatings containing eugenol side groups prepared in Example 1 and Comparative Example 1 on the static adhesion of diatoms at 24 h and 7 d.

[0037] Figure 3 is a comparison chart of the inhibitory effects of Example 1 and Comparative Example 1 on the static adhesion of bacterial biofilms. Detailed Embodiments

[0038] The following further specific descriptions of the present invention are made in conjunction with the drawings and specific embodiments, and the above and / or other advantages of the present invention will become clearer.

[0039] In the following examples, the content of eugenol was calculated by nuclear magnetic resonance hydrogen spectrum ( 1 1H-NMR).

[0040] In the following examples, the static adhesion test of diatoms was carried out according to the following test steps: The polyurethane coating containing eugenol side groups was co-cultured with 1 mL of diatom culture solution for 24 h and 7 d under the conditions of a light intensity of 1500 Lux, 25 °C, and 12 h light / 12 h darkness. An inverted microscope was used to observe and select 5 fields of view, and the diatoms attached to the surface of the coating were counted. Five parallel samples were tested in each example. The adhesion density of diatoms on the coating was calculated by the following formula:

[0041]

[0042] The static adhesion test of the bacterial biofilm is carried out according to the following steps: Co-culture the eugenol-side-group polyurethane coating with 1 mL of bacterial suspension in an incubator at 30 °C for 48 h. Stain the bacterial biofilm attached to the coating surface with 0.4 wt% crystal violet solution, gently rinse with running water, dry at 37 °C, add 1.0 mL of 33% v / v glacial acetic acid solution to dissolve the crystal violet, and measure the absorbance of the dissolution solution at 590 nm using a multifunctional microplate reader. Five parallel samples are tested in each example.

[0043] The coating mass loss test is carried out according to the following steps: Weigh the ampoule bottles with a certain thickness of eugenol-side-group polyurethane coating at the bottom, which is recorded as the original mass. Add an appropriate amount of filtered seawater (replaced regularly) to each ampoule bottle and irradiate it under simulated natural light conditions for 60 d. After irradiation, rinse it with deionized water multiple times to remove the salt on the coating surface, dry it in a forced-air drying oven at 40 °C to a constant weight, and weigh it, which is recorded as the mass on the nth day of irradiation. Three parallel samples are tested in each example. The mass loss of the eugenol-side-group polyurethane coating can be calculated by the following formula:

[0044]

[0045] Example 1

[0046] Under vacuum conditions, lactide (0.5 equiv.), glycolide (0.5 equiv.), ethylene glycol (0.20 equiv.) and stannous octoate (0.3 wt‰) are subjected to ring-opening polymerization reaction in a reaction kettle at 160 °C for 45 min to obtain poly(lactic acid-glycolic acid) diol.

[0047] Under an inert gas atmosphere and ultraviolet light conditions, eugenol (1.0 equiv.), 3-mercapto-1,2-propanediol (1.0 equiv.), 2-hydroxy-2-methyl-1-phenyl-1-propanone (2.0 wt%) are subjected to a thiol-ene click reaction in a reaction kettle for 3.5 h to obtain eugenol polyol.

[0048] In an inert gas atmosphere, poly(lactic acid-glycolic acid) diol (6.67 equiv.), eugenol polyol (11.00 equiv.), isophorone diisocyanate (27.50 equiv.), 1,4-butanediol (9.83 equiv.), dibutyltin dilaurate (2 wt‰) are dissolved in tetrahydrofuran and subjected to polycondensation reaction at 80 °C for 5.0 h. After the reaction, it is dropped into n-hexane to produce a pale yellow viscous substance, namely the eugenol-side-group polyurethane. The amount of tetrahydrofuran used is calculated based on adding a total of 20 g of aliphatic polyester diol and eugenol polyol per 100 mL of tetrahydrofuran; the volume ratio of n-hexane used to tetrahydrofuran is 5:1.

[0049] Dissolve the eugenol - side - group polyurethane in acetone to prepare a mixed solution with a weight - volume ratio of 20% (w / v, g / mL). Coat the mixed solution onto a glass slide with a diameter of 15 mm by the solution casting method, place it in a fume hood to dry, wash it with distilled water until no impurities remain on the surface, and then dry it naturally to obtain the eugenol - side - group polyurethane coating.

[0050] For the eugenol - side - group polyurethane coating obtained in this example, from 1 the \(^1H\) - NMR spectrum (as Figure 1 ) analysis shows that the eugenol content is about 15 wt%. The indoor static adhesion test of diatoms shows that the 24 - h diatom adhesion density of the eugenol - side - group polyurethane coating obtained in this example is 46 cell / mm 2 , and the 7 - d diatom adhesion density is 58 cell / mm 2 . The static adhesion test of bacterial biofilms shows that the absorbance of the biofilm of Micrococcus luteus is 0.64. The coating mass loss test shows that the 60 - d mass loss of the eugenol - side - group polyurethane coating obtained in this example is 18.34 mg / cm 2 .

[0051] Example 2

[0052] Under vacuum conditions, lactide (0.5 equiv.), caprolactone (0.5 equiv.), propylene glycol (0.15 equiv.) and stannous chloride dihydrate (0.2 wt‰) are subjected to ring - opening polymerization reaction in a reaction kettle at 170 °C for 1.0 h to obtain poly(lactic acid - caprolactone) diol.

[0053] Under an inert gas atmosphere and ultraviolet light conditions, eugenol (1.0 equiv.), 1,4 - dithiothreitol (1.0 equiv.), isopropyl thioxanthone (2,4 isomeric mixture) (3.0 wt%) are subjected to a thiol - ene click reaction in a reaction kettle for 5.0 h to obtain eugenol polyol.

[0054] Under an inert gas atmosphere, poly(lactic acid - caprolactone) diol (6.67 equiv.), eugenol polyol (11.00 equiv.), lysine diisocyanate (29.65 equiv.), ethylene glycol (15.64 equiv.), stannous octoate (3 wt‰) are dissolved in dichloromethane, and a polycondensation reaction is carried out at 80 °C for 4.5 h. After the reaction is completed, it is dropped into petroleum ether to produce a pale - yellow viscous substance, namely the eugenol - side - group polyurethane. The amount of dichloromethane used is calculated based on adding a total weight of 25 g of aliphatic polyester diol and eugenol polyol per 100 mL of dichloromethane; the volume ratio of the petroleum ether used to the dichloromethane is 7.5:1.

[0055] Dissolve the eugenol side group polyurethane in tetrahydrofuran to prepare a mixed solution with a weight - volume ratio of 15% (w / v, g / mL). Coat the mixed solution on a glass slide with a diameter of 15 mm by the solution casting method, place it in a fume hood to dry, wash it with distilled water until there is no impurity residue on the surface, and dry it naturally to obtain the eugenol side group polyurethane coating.

[0056] The eugenol content of the eugenol side group polyurethane coating obtained in this example is about 10 wt%. The indoor diatom static adhesion test shows that the 24 - hour diatom adhesion density of the eugenol side group polyurethane coating obtained in this example is 194 cell / mm 2 and the 7 - day diatom adhesion density is 159 cell / mm 2 The bacterial biofilm static adhesion test shows that the absorbance of the Micrococcus luteus biofilm in the sea is 1.23; the coating mass loss test shows that the 60 - day mass loss of the eugenol side group polyurethane coating obtained in this example is 17.14 mg / cm 2 .

[0057] Example 3

[0058] Under vacuum conditions, lactide (1.0 equiv.), ethylene glycol (0.2 equiv.) and stannous octoate (0.25 wt‰) are subjected to ring - opening polymerization reaction in a reaction kettle at 165 °C for 1.0 h to obtain polylactic acid diol.

[0059] Under an inert gas atmosphere and ultraviolet light conditions, eugenol (1.0 equiv.), 3 - mercapto - 1,2 - propanediol (1.0 equiv.) and 2 - hydroxy - 2 - methyl - 1 - phenyl - 1 - propanone (1.0 wt%) are subjected to a thiol - ene click reaction in a reaction kettle for 4.0 h to obtain eugenol polyol.

[0060] In an inert gas atmosphere, polylactic acid diol (6.67 equiv.), eugenol polyol (11.00 equiv.), hexamethylene diisocyanate (27.50 equiv.), 1,4-butanediol (9.83 equiv.), and stannous octoate (2 wt‰) were dissolved in tetrahydrofuran, and a polycondensation reaction was carried out at 70 °C for 5.0 h. After the reaction, the mixture was dropped into n-hexane to produce a pale yellow viscous substance, namely, polyurethane containing eugenol side groups. The amount of tetrahydrofuran used was calculated based on adding aliphatic polyester diol and eugenol polyol with a total weight of 30 g per 100 mL of tetrahydrofuran; the volume ratio of the amount of n-hexane used to the volume of tetrahydrofuran was 5:1. The polyurethane containing eugenol side groups was dissolved in acetone to prepare a mixed solution with a weight-to-volume ratio of 10% (w / v, g / mL). The mixed solution was coated on a glass slide with a diameter of 15 mm by the solution casting method, placed in a fume hood for drying, washed with distilled water until no impurities remained on the surface, and naturally dried to obtain a polyurethane coating containing eugenol side groups.

[0061] The eugenol content of the polyurethane coating containing eugenol side groups obtained in this example was approximately 15 wt%; the indoor static adhesion test of diatoms showed that the 24-h diatom adhesion density of the polyurethane coating containing eugenol side groups obtained in this example was 315 cell / mm 2 and the 7-d diatom adhesion density was 298 cell / mm 2 ; the static adhesion test of bacterial biofilms showed that the absorbance of the biofilm of Micrococcus luteus was 1.64; the coating mass loss test showed that the 60-d mass loss of the polyurethane coating containing eugenol side groups obtained in this example was 16.63 mg / cm 2 .

[0062] Comparative Example 1

[0063] Using a glass slide without any coating as a control group, indoor static adhesion tests of marine diatoms and bacterial biofilms were carried out.

[0064] The indoor static antifouling test showed that the 24-h diatom adhesion density of the blank glass slide was 925 cell / mm 2 and the 7-d diatom adhesion density was 1347 cell / mm 2 ; the crystal violet absorbance of Micrococcus luteus was 3.08.

[0065] Comparative Example 2

[0066] Under vacuum conditions, lactide (1.0 equiv.), ethylene glycol (0.15 equiv.), and stannous octoate (0.15 wt‰) were subjected to a ring-opening polymerization reaction in a reaction kettle at 165 °C for 1.0 h to obtain polylactic acid diol.

[0067] In an inert gas atmosphere, polylactic acid diol (6.67 equiv.), isophorone diisocyanate (33.93 equiv.), 1,6 - hexanediol (27.26 equiv.), and dibutyltin dilaurate (2 wt‰) were dissolved in acetone, and a polycondensation reaction was carried out at 70 °C for 5.0 h. After the reaction, the mixture was dropped into petroleum ether to produce a white viscous substance, namely polyurethane. The amount of acetone used was calculated as adding 50 g of polylactic acid diol per 100 mL of acetone; the volume ratio of the petroleum ether used to acetone was 10:1.

[0068] The polyurethane was dissolved in acetone to prepare a mixed solution with a weight - volume ratio of 10% (w / v, g / mL). The mixed solution was coated on a glass slide with a diameter of 15 mm by the solution casting method, placed in a fume hood for drying, washed with distilled water until no impurities remained on the surface, and then naturally dried to obtain a polyurethane coating.

[0069] Indoor static anti - fouling tests showed that the diatom adhesion density of the polyurethane coating obtained in this comparative example was 686 cell / mm 2 after 24 h, and 593 cell / mm 2 after 7 d. The absorbance of the biofilm of Micrococcus luteus in the ocean was 2.67; the coating mass loss test showed that the mass loss of the polyurethane coating with eugenol side groups obtained in this comparative example was 11.57 mg / cm 2 .

[0070] Comparative Example 3

[0071] Under vacuum conditions, glycolide (0.1 equiv.), hexanediol (0.2 equiv.), and stannous chloride dihydrate (0.3 wt‰) were subjected to a ring - opening polymerization reaction in a 170 °C reactor for 1.5 h to obtain polyglycolic acid diol.

[0072] In an inert gas atmosphere, polyglycolic acid diol (6.67 equiv.), toluene diisocyanate (33.93 equiv.), diethylene glycol (27.26 equiv.), and stannous octoate (3.0 wt‰) were dissolved in tetrahydrofuran, and a polycondensation reaction was carried out at 80 °C for 6.0 h. After the reaction, the mixture was dropped into n - hexane to produce a white viscous substance, namely polyurethane. The amount of tetrahydrofuran used was calculated as adding 40 g of polyglycolic acid diol per 100 mL of tetrahydrofuran; the volume ratio of the n - hexane used to tetrahydrofuran was 7.5:1.

[0073] The polyurethane was dissolved in tetrahydrofuran to prepare a mixed solution with a weight - volume ratio of 20% (w / v, g / mL). The mixed solution was coated on a glass slide with a diameter of 15 mm by the solution casting method, placed in a fume hood for drying, washed with distilled water until no impurities remained on the surface, and then naturally dried to obtain a polyurethane coating.

[0074] Indoor static anti-fouling tests showed that the diatom adhesion density of the polyurethane coating obtained in this comparative example was 541 cells / mm after 24 h 2 , and the diatom adhesion density was 416 cells / mm after 7 d 2 . The absorbance of the biofilm of Micrococcus luteus was 2.45; the coating mass loss test showed that the mass loss of the eugenol-side-group-containing polyurethane coating obtained in this comparative example was 12.84 mg / cm after 60 d 2 .

[0075] From attachment Figure 2 and attachment Figure 3 it can be seen that compared with the high diatom adhesion density and high bacterial biofilm coverage of the blank glass slide in Comparative Example 1, the glass slide coated with the eugenol-side-group-containing polyurethane coating had only very few diatom adhesions and a lower bacterial biofilm coverage, indicating that the eugenol-side-group-containing polyurethane coating had excellent static anti-fouling performance. The above results showed that the eugenol-side-group-containing polyurethane coating of the present invention had fast and controllable degradability and excellent static anti-fouling performance, and would not release harmful substances into the environment. The preparation method was simple and the raw materials were widely available, which was conducive to industrial promotion.

[0076] The present invention provided an idea and method for an eugenol-side-group-containing polyurethane coating, its preparation method and application. There were many methods and ways to specifically implement this technical solution. The above was only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements could be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Each component not clearly defined in this embodiment could be implemented using existing technologies.

Claims

1. A preparation method of a polyurethane coating containing eugenol side groups, characterized in that, It includes the following steps: (1) Under vacuum conditions, an aliphatic lactone, a diol, and a first catalyst are subjected to a ring-opening polymerization reaction to obtain an aliphatic polyester diol; (2) Under an inert gas atmosphere and ultraviolet light conditions, eugenol, a mercapto alcohol compound, and a photoinitiator are subjected to a thiol-ene click reaction to obtain eugenol polyol; (3) In an inert gas atmosphere, the aliphatic polyester diol, the eugenol polyol, a diisocyanate, a chain extender, and a second catalyst are dissolved in a first solvent for polycondensation reaction. After the reaction is completed, it is dropped into a second solvent to obtain a polyurethane with eugenol side groups; (4) The polyurethane with eugenol side groups is dissolved in a third solvent, coated on a substrate by a solution casting method, washed with water after drying, and then dried to obtain a polyurethane coating with eugenol side groups; Among them, in step (1), the aliphatic lactone is any one or a combination of lactide, glycolide, or caprolactone; the diol is any one or a combination of ethylene glycol, propylene glycol, 1,4-butanediol, or glycerol; the first catalyst is any one or a combination of stannous octoate or stannous chloride dihydrate; the feeding molar ratio of the diol to the aliphatic lactone is 1:5 to 1:10; the dosage of the first catalyst is 0.1 wt‰ to 0.3 wt‰; for the ring-opening polymerization reaction, the reaction time is 0.5 to 1.5 h, and the reaction temperature is 160 to 180 °C; in step (2), the mercapto alcohol compound is any one or a combination of 3-mercapto-1,2-propanediol, 1,4-dithiothreitol, or 1,4-dimercapto-2,3-butanediol; the photoinitiator is any one or a combination of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, isopropylthioxanthone, or 2,4-diethylthiazolone; the feeding molar ratio of eugenol to 3-mercapto-1,2-propanediol is 1:1; the addition amount of the photoinitiator is 0.5 wt% to 3.0 wt%; for the thiol-ene click reaction, the reaction time is 3.0 to 5.0 h; In step (3), the diisocyanate is any one or a combination of isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, lysine diisocyanate or dicyclohexylmethane diisocyanate; the chain extender is any one or a combination of 1,4-butanediol, 1,6-hexanediol or diethylene glycol; the second catalyst is any one or a combination of dibutyltin dilaurate or stannous octoate; the first solvent is any one or a combination of tetrahydrofuran, dichloromethane or acetone; the second solvent is any one or a combination of n-hexane or petroleum ether; the molar ratio of the aliphatic polyester diol, eugenol polyol, diisocyanate and chain extender is 6.67:3.67 to 11.00:27.50 to 33.93:9.83 to 27.26; the dosage of the second catalyst is 1 wt‰ to 5 wt‰; The volume of the first solvent is calculated based on adding a total weight of 20 to 50 g of the aliphatic polyester diol and eugenol polyol per 100 mL of the first solvent; the volume ratio of the second solvent to the first solvent is 5:1 to 10:1; for the polycondensation reaction, the reaction temperature is 70 to 80 °C and the reaction time is 3 to 8 h; In step (4), the third solvent is any one or a combination of tetrahydrofuran, dichloromethane or acetone; the volume of the third solvent is calculated based on adding 10 to 30 g of the eugenol side group-containing polyurethane per 100 mL of the third solvent.

2. The eugenol side group-containing polyurethane coating prepared by the preparation method according to claim 1.

3. The application of the eugenol side group-containing polyurethane coating according to claim 2 in water body antifouling.

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