A polyester cord coated with a polyurethane nanocomposite coating and a method of making the same

Abstract

This invention discloses a polyester cable with a polyurethane nanocomposite coating and its preparation method. The method involves coating the surface of a polyester cable with a composite coating of fluorinated polyurethane and aminated nano-zinc oxide. The method includes preparing a fluorinated chain extender; preparing aminated nano-zinc oxide; reacting diisocyanate, polyol, and catalyst to obtain a prepolymer, then adding a fluorinated chain extender, a small molecule chain extender, and tetrahydrofuran to obtain a fluorinated polyurethane solution; dispersing the aminated nano-zinc oxide in the fluorinated polyurethane solution to obtain a fluorinated polyurethane nanocomposite solution; immersing the polyester cable in the fluorinated polyurethane nanocomposite solution, removing it, air-drying, and baking it; repeating this process several times to obtain the polyester cable with the polyurethane nanocomposite coating. The polyester cable of this invention possesses UV resistance, seawater corrosion resistance, and marine antifouling properties. The preparation method is simple, and it has broad application prospects in marine engineering, ship mooring, and marine fisheries.

Description

Technical Field

[0001] This invention relates to a polyester cable and its preparation method, and more particularly to a polyester cable coated with a polyurethane nanocomposite coating and its preparation method. Background Technology

[0002] Polyester cables, with their outstanding advantages such as high strength and low specific gravity, have become the preferred material to replace traditional steel cables in the marine field and are widely used in various offshore operations. However, the marine environment includes multiple harsh factors such as strong ultraviolet radiation, high-salt corrosive media, and marine organism attachment. During long-term service, the surface of polyester cables is prone to aging, corrosion, and fouling, leading to continuous performance degradation and a significant reduction in service life. This not only increases the maintenance costs of marine operations but may also pose safety hazards.

[0003] In existing technologies, coating protection is the main means of improving the marine environmental adaptability of polyester cables. Among them, polyurethane is widely used for cable surface protection due to its good flexibility and adhesion. However, the UV aging resistance and marine antifouling performance of a single polyurethane coating are limited, making it difficult to resist strong marine UV radiation and biofouling, and thus unable to meet the requirements for long-term service.

[0004] To improve the protective performance of polyurethane coatings, existing technologies often employ fluorine modification to reduce the surface energy of the coating, thereby enhancing its resistance to seawater erosion and marine antifouling properties. In addition, attempts have been made to prepare protective coatings by combining nanomaterials with polyurethane; however, this approach suffers from poor dispersibility of nanomaterials and incompatible compatibility with the polyurethane matrix, leading to decreased coating adhesion, unstable protective effects, and difficulty in meeting the stringent requirements of marine engineering for polyester cables.

[0005] To address the aforementioned issues, a polyurethane nanocomposite coating that combines UV resistance, seawater corrosion resistance, and marine antifouling properties has been developed. This coating is simple to prepare, uniformly dispersed, and exhibits strong adhesion. It has significant application value and market prospects for promoting the technological upgrading of cable materials used in marine engineering. Summary of the Invention

[0006] To overcome the problems existing in the background art, the present invention provides a polyester cable coated with a polyurethane nanocomposite coating and its preparation method. The preparation method of the present invention is simple, and the resulting polyester cable has good UV resistance, seawater corrosion resistance, and marine antifouling performance, and has broad application prospects in marine engineering, ship mooring, and marine fisheries.

[0007] To achieve the above objectives, the present invention involves coating a polyester cable with a composite coating of fluorinated polyurethane and aminated nano-zinc oxide. The method includes: preparing a fluorinated chain extender; preparing aminated nano-zinc oxide; reacting diisocyanate, polyol, and catalyst to obtain a prepolymer, then adding a fluorinated chain extender, a small molecule chain extender, and tetrahydrofuran to obtain a fluorinated polyurethane solution; dispersing the aminated nano-zinc oxide in the fluorinated polyurethane solution to obtain a fluorinated polyurethane nanocomposite material solution; immersing the polyester cable in the fluorinated polyurethane nanocomposite material solution, removing it, air-drying, and baking it; repeating this process several times to obtain a polyester cable coated with a polyurethane nanocomposite coating.

[0008] More specifically, the specific technical solution adopted by the present invention to solve its technical problem is as follows: I. A polyester cable coated with a polyurethane nanocomposite coating: The surface of the polyester cable is coated with a composite coating of fluorinated polyurethane and aminated nano zinc oxide. The fluorinated polyurethane is mainly polymerized from diisocyanate, polyol, fluorinated chain extender and small molecule chain extender. The fluorinated chain extender is prepared by reacting 1-thioglycerol with 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl methacrylate, and its chemical structure is shown below: The aminated nano zinc oxide is prepared by modifying the surface of nano zinc oxide with an amino-containing silane coupling agent.

[0009] The molar ratio of the diisocyanate, polyol, fluorinated chain extender and small molecule chain extender is 16.3:3.5:3-6:9-6.

[0010] The diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, and cyclohexyl diisocyanate; The polyol is at least one of polypropylene glycol, polyoxypropylene polyol, and polytetrahydrofuran ether glycol; The small molecule chain extender is at least one of 1,4-butanediol, ethylene glycol, and hexanediol.

[0011] The content of the aminated nano zinc oxide in the composite coating of fluorinated polyurethane and aminated nano zinc oxide is 1-2 wt%, and the remaining components in the composite coating of fluorinated polyurethane and aminated nano zinc oxide are all fluorinated polyurethane except for the aminated nano zinc oxide.

[0012] II. A method for preparing a polyester cable coated with a polyurethane nanocomposite coating, the method comprising the following steps: Step 1) 1-Thioglycerol and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl methacrylate are reacted at a certain temperature to obtain a fluorinated chain extender. Step 2) The hydrolyzed 3-aminopropyltriethoxysilane is added dropwise to the nano zinc oxide suspension and reacted at a certain temperature to obtain aminated nano zinc oxide; Step 3) Under a nitrogen atmosphere, diisocyanate, polyol and catalyst are reacted at a certain temperature to obtain a prepolymer. The fluorinated chain extender, small molecule chain extender and tetrahydrofuran obtained in step 1) are added to the prepolymer, the reaction is continued, and tetrahydrofuran is added to dilute the solution to obtain a fluorinated polyurethane solution. Step 4) Disperse the aminated nano zinc oxide obtained in step 2) in tetrahydrofuran, and then add it dropwise to the fluorinated polyurethane solution obtained in step 3). Stir at a certain temperature until it is uniform and stable to obtain a fluorinated polyurethane nanocomposite solution. Step 5) After fully immersing the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in Step 4), remove it, air dry it, and then dry it to constant weight. Step 6) Repeat step 5) several times to obtain the polyester cable with polyurethane nanocomposite coating.

[0013] Step 1) specifically involves using triethylamine as a catalyst to add 1-thioglycerol, 3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluorooctyl methacrylate to tetrahydrofuran, and reacting at 30-40°C for 4-8 hours to obtain a fluorinated chain extender; wherein the molar ratio of 1-thioglycerol, 3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluorooctyl methacrylate, and triethylamine is 2:1:2.

[0014] Step 2) specifically involves adding 3-aminopropyltriethoxysilane to a mixed solution of anhydrous ethanol and deionized water, adjusting the pH to 4-5, and stirring at room temperature for 20-40 min to hydrolyze the 3-aminopropyltriethoxysilane; adding nano-zinc oxide to anhydrous ethanol and sonicating for 20-40 min to obtain a suspension of nano-zinc oxide; adding the hydrolyzed 3-aminopropyltriethoxysilane solution dropwise to the nano-zinc oxide suspension, with a mass ratio of 3-aminopropyltriethoxysilane to nano-zinc oxide of 1:1, reacting at 50-65℃ for 1-4 h, centrifuging, washing successively with anhydrous ethanol and deionized water, and drying to obtain aminated nano-zinc oxide.

[0015] Step 3) specifically involves stirring diisocyanate, polyol, and catalyst at 65-85°C for 1-3 hours under a nitrogen atmosphere to obtain a prepolymer. The catalyst is at least one of dibutyltin dilaurate and stannous octoate. The molar ratio of diisocyanate to polyol is 16.3:3.5, and the amount of catalyst used is 0.05% of the total mass of diisocyanate, polyol, fluorinated chain extender, and small molecule chain extender. The fluorinated chain extender, small molecule chain extender, and tetrahydrofuran obtained in step 1) are added to the prepolymer. The molar ratio of prepolymer, fluorinated chain extender, and small molecule chain extender is 19.8:3-6:9-6, and the amount of tetrahydrofuran used is 1.5 times the total mass of the reactants. The mixture is stirred and reacted at 65-85°C for another 1-3 hours. Tetrahydrofuran is then added to dilute the solid content of the fluorinated polyurethane to 20-40% by mass, resulting in a fluorinated polyurethane solution.

[0016] Step 4) specifically involves dispersing the aminated nano-zinc oxide obtained in step 2) in tetrahydrofuran, and then adding it dropwise to the fluorinated polyurethane solution obtained in step 3), such that the proportion of the aminated nano-zinc oxide in the total mass of the fluorinated polyurethane and the aminated nano-zinc oxide in the fluorinated polyurethane solution is 1-2 wt%, and stirring at 60-90℃ for 5-15 min to obtain a fluorinated polyurethane nanocomposite solution.

[0017] Step 5) specifically involves fully immersing the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 4), removing the polyester cable, air-drying it naturally for 24-48 hours, and then transferring it to a 60-80℃ oven to dry to a constant weight.

[0018] The beneficial effects of this invention are: This invention achieves three core protective functions—UV resistance, seawater corrosion resistance, and marine antifouling—by coating the surface of polyester cables with a composite coating of fluorinated polyurethane and aminated nano-zinc oxide. This solves the problems of existing polyester cables being prone to aging, corrosion, and fouling in marine environments, making it suitable for harsh marine operations such as marine engineering, ship mooring, and offshore fishing. In the composite coating, the fluorinated polyurethane, relying on the low surface energy of fluorine, effectively enhances the coating's resistance to seawater corrosion and marine antifouling, resisting the erosion of high-salt seawater and reducing the attachment of marine organisms such as barnacles and algae. The aminated nano-zinc oxide not only possesses excellent UV shielding capabilities, effectively blocking strong marine UV radiation and inhibiting the aging and breakage of polyester molecular chains, but its aminated modification also significantly improves its compatibility with the fluorinated polyurethane matrix, preventing nanoparticle aggregation and resulting in a denser coating structure and a longer-lasting and stable protective effect.

[0019] The preparation method of this invention is simple and easy to implement, requiring no complex production equipment or harsh reaction conditions. It can produce polyester cables coated with a composite coating of fluorinated polyurethane and aminated nano-zinc oxide. The method is convenient, has low production costs, and is easy to scale up and promote. The aminated nano-zinc oxide is uniformly dispersed in the fluorinated polyurethane solution and tightly bonded to the matrix. After being coated onto the surface of the polyester cable, it forms a dense composite coating with strong adhesion, resistance to peeling and cracking, and can maintain excellent protective performance in the harsh marine environment of strong ultraviolet radiation, high salt corrosion, and biofouling for a long time. This effectively solves the technical problems of poor dispersion and insufficient adhesion of existing nanocomposite coatings. The raw materials used in this invention are readily available, and the preparation process is green and environmentally friendly, generating no harmful pollutants. This ensures product safety and meets environmental protection requirements. At the same time, it expands the application scope of polyester cables in the marine engineering field, possessing significant practical value and broad market application prospects. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to specific embodiments.

[0021] The embodiments of the present invention are as follows: In the following examples, isophorone diisocyanate (99%), polytetrahydrofuran ether diol (AR), dibutyltin dilaurate (95%), 1-thioglycerol (99%), 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecyl octyl methacrylate (98%), triethylamine (99%), and nano zinc oxide (90%) 10nm) and 3-aminopropyltriethoxysilane (99%) are commercially available materials.

[0022] UV resistance test method: The transmittance of the polyurethane nanocomposite coating in the range of 200-800 nm was tested using a Hitachi UH 4150 UV-Vis-NIR spectrophotometer.

[0023] Seawater erosion resistance test method: Before testing, the sample was placed in a 50 ºC forced-air drying oven for 24 hours to remove any residual moisture, and its initial dry weight (W0) was recorded. The dried sample was then completely immersed in artificial seawater and stored under constant temperature conditions to simulate a long-term seawater service environment. Every 30 days, the sample was removed, the surface moisture was blotted dry with filter paper, and the wet weight (W0) was measured. t The water absorption rate was calculated based on the changes in wet and dry weight over different immersion periods to evaluate the samples' resistance to seawater erosion in a long-term seawater environment. The formula for calculating the water absorption rate is: Water absorption rate = ((W) t -W0) / W0)×100% In the formula, W t : Wet weight, g; W0: Dry weight, g.

[0024] Marine antifouling performance testing method: *Nyctaginosa* was used in an anti-diatom test to simulate marine antifouling performance. Sodium metasilicate (7.3 mg / L) was added to artificial seawater as a silicon source for diatom growth. Sterilized seawater and algae were mixed at a volume ratio of 3:1 and cultured in a 25°C constant temperature and humidity incubator for 48 hours under 12h / 12h light-dark cycles. Subsequently, the samples were immersed in an algal suspension culture at 25°C for 7 days. After immersion, the samples were gently rinsed with artificial seawater to remove any unattached algae, and the algal coverage on the sample surface was observed using a laser confocal scanning electron microscope.

[0025] Coating adhesion test: The cross-cut adhesion test was conducted in accordance with ISO 2409:2020 standard.

[0026] Example 1: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) Add 2 g of 3-aminopropyltriethoxysilane to a mixed solution of 20 mL of anhydrous ethanol and 2 mL of deionized water, adjust the pH to 4-5, stir at room temperature for 30 min to hydrolyze the 3-aminopropyltriethoxysilane; add 2 g of nano zinc oxide to 100 mL of anhydrous ethanol, sonicate for 30 min to obtain a suspension of nano zinc oxide; add the hydrolyzed 3-aminopropyltriethoxysilane dropwise to the suspension of nano zinc oxide, react at 60 °C for 3 h, centrifuge, wash with anhydrous ethanol and deionized water in sequence, and dry in a 50 °C oven to obtain aminated nano zinc oxide; (3) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 32.4 g of the fluorinated chain extender obtained in step 1), 5.4 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the mixture was stirred and reacted at 80 °C for 2 h. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution; (4) Add 2g of the aminated nano zinc oxide obtained in step 2) to 100mL of tetrahydrofuran, disperse it by ultrasonication for 30min, and then take 15mL and add it dropwise to 100mL of the fluorinated polyurethane solution obtained in step 3). Stir at 80℃ for 10min to obtain the fluorinated polyurethane nanocomposite solution. (5) Immerse the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 4), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (6) Repeat step 5) several times to make the mass fraction of the fluorinated polyurethane nanocomposite coating in the polyester cable after coating 20wt%, and obtain the polyester cable for marine engineering with polyurethane nanocomposite coating.

[0027] UV resistance test results: transmittance at 350nm is 4.6%; seawater corrosion resistance test results: water absorption rate is 12.0% after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate is 0.52%; coating adhesion test results: grade 0.

[0028] Example 2: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) Add 2 g of 3-aminopropyltriethoxysilane to a mixed solution of 20 mL of anhydrous ethanol and 2 mL of deionized water, adjust the pH to 4-5, stir at room temperature for 30 min to hydrolyze the 3-aminopropyltriethoxysilane; add 2 g of nano zinc oxide to 100 mL of anhydrous ethanol, sonicate for 30 min to obtain a suspension of nano zinc oxide; add the hydrolyzed 3-aminopropyltriethoxysilane dropwise to the suspension of nano zinc oxide, react at 60 °C for 3 h, centrifuge, wash with anhydrous ethanol and deionized water in sequence, and dry in a 50 °C oven to obtain aminated nano zinc oxide; (3) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 32.4 g of the fluorinated chain extender obtained in step 1), 5.4 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the mixture was stirred and reacted at 80 °C for 2 h. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution; (4) Add 2g of the aminated nano zinc oxide obtained in step 2) to 100mL of tetrahydrofuran, disperse it by ultrasonication for 30min, and then take 22.5mL and add it dropwise to 100mL of the fluorinated polyurethane solution obtained in step 3). Stir at 80℃ for 10min to obtain the fluorinated polyurethane nanocomposite solution. (5) Immerse the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 4), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (6) Repeat step 5) several times to make the mass fraction of the fluorinated polyurethane nanocomposite coating in the polyester cable after coating 20wt%, and obtain the polyester cable for marine engineering with polyurethane nanocomposite coating.

[0029] UV resistance test results: transmittance at 350nm is 1.2%; seawater corrosion resistance test results: water absorption rate is 12.3% after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate is 0.37%; coating adhesion test results: grade 0.

[0030] Example 3: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) Add 2 g of 3-aminopropyltriethoxysilane to a mixed solution of 20 mL of anhydrous ethanol and 2 mL of deionized water, adjust the pH to 4-5, stir at room temperature for 30 min to hydrolyze the 3-aminopropyltriethoxysilane; add 2 g of nano zinc oxide to 100 mL of anhydrous ethanol, sonicate for 30 min to obtain a suspension of nano zinc oxide; add the hydrolyzed 3-aminopropyltriethoxysilane dropwise to the suspension of nano zinc oxide, react at 60 °C for 3 h, centrifuge, wash with anhydrous ethanol and deionized water in sequence, and dry in a 50 °C oven to obtain aminated nano zinc oxide; (3) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 32.4 g of the fluorinated chain extender obtained in step 1), 5.4 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the mixture was stirred and reacted at 80 °C for 2 h. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution; (4) Add 2g of the aminated nano zinc oxide obtained in step 2) to 100mL of tetrahydrofuran, disperse it by ultrasonication for 30min, and then take 30mL and add it dropwise to 100mL of the fluorinated polyurethane solution obtained in step 3). Stir at 80℃ for 10min to obtain the fluorinated polyurethane nanocomposite solution. (5) Immerse the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 4), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (6) Repeat step 5) several times to make the mass fraction of the fluorinated polyurethane nanocomposite coating in the polyester cable after coating 20wt%, and obtain the polyester cable for marine engineering with polyurethane nanocomposite coating.

[0031] UV resistance test results: transmittance at 350nm is 0.16%; seawater corrosion resistance test results: water absorption rate is 12.5% ​​after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate is 0.22%; coating adhesion test results: grade 0.

[0032] Comparative Example 1: Plain polyester cable without any coating or modification.

[0033] UV resistance test results: No coating, not applicable; Seawater corrosion resistance test results: Water absorption rate of 46.9% after immersion in artificial seawater for 10 minutes; Marine antifouling performance test results: Diatom adhesion rate of 1.91%; Coating adhesion test results: No coating, not applicable.

[0034] Comparative Example 2: (1) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain polyurethane prepolymer; 10.8 g of 1,4-butanediol and tetrahydrofuran were added to the polyurethane prepolymer, and the mixture was stirred and reacted at 80 °C for 2 h. Tetrahydrofuran was added to dilute the solid content of the polyurethane to 30% to obtain polyurethane solution. (2) Soak the polyester cable in the polyurethane solution obtained in step 1) thoroughly, take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60°C oven to dry until constant weight. (3) Repeat step 2) several times to make the mass fraction of polyurethane coating in the polyester cable after coating 20wt%, and obtain the polyester cable for marine engineering with polyurethane coating.

[0035] UV resistance test results: 80.8% transmittance at 350nm; seawater corrosion resistance test results: 24.8% water absorption rate after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate 0.95%; coating adhesion test results: grade 0.

[0036] Comparative Example 3: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 16.2 g of the fluorinated chain extender obtained in step 1), 8.1 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the reaction was continued at 80 °C for 2 h with stirring. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution. (3) Immerse the polyester cable in the fluorinated polyurethane solution obtained in step 2), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (4) Repeat step 3) several times to make the mass fraction of the fluorinated polyurethane coating in the polyester cable after coating 20wt%, and obtain the polyester cable for marine engineering with polyurethane coating.

[0037] UV resistance test results: transmittance at 350nm is 76.2%; seawater corrosion resistance test results: water absorption rate is 18.6% after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate is 0.85%; coating adhesion test results: grade 0.

[0038] Comparative Example 4: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 32.4 g of the fluorinated chain extender obtained in step 1), 5.4 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the reaction was continued at 80 °C for 2 h with stirring. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution. (3) Immerse the polyester cable in the fluorinated polyurethane solution obtained in step 2), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (4) Repeat step 3) several times to make the mass fraction of the fluorinated polyurethane coating in the polyester cable after coating 20wt%, and obtain the polyester cable for marine engineering with polyurethane coating.

[0039] UV resistance test results: transmittance at 350nm is 69.4%; seawater corrosion resistance test results: water absorption rate is 12.9% after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate is 0.75%; coating adhesion test results: grade 0.

[0040] Comparative Example 5: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 32.4 g of the fluorinated chain extender obtained in step 1), 5.4 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the reaction was continued at 80 °C for 2 h with stirring. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution. (3) Add 2g of nano zinc oxide to 100mL of tetrahydrofuran, disperse it by ultrasonication for 30min, and then take 30mL and add it dropwise to 100mL of the fluorinated polyurethane solution obtained in step 2). Stir at 80℃ for 10min to obtain the fluorinated polyurethane nanocomposite solution. (4) Immerse the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 3), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (5) Repeat step 4) several times to make the mass fraction of the fluorinated polyurethane nanocomposite coating in the polyester cable after coating 20wt%, and obtain the marine engineering polyester cable with polyurethane nanocomposite coating.

[0041] UV resistance test results: transmittance at 350nm is 0.16%; seawater corrosion resistance test results: water absorption rate is 16.7% after immersion in artificial seawater for 30 days; marine antifouling performance test results: diatom adhesion rate is 0.42%; coating adhesion test results: grade 0.

[0042] Comparative Example 6: (1) 21.6 g of 1-thioglycerol, 43.2 g of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl ester of methacrylate and 20.2 g of triethylamine were added to 200 mL of tetrahydrofuran and reacted at 35 °C for 6 h to obtain a fluorinated chain extender; (2) Add 2 g of 3-aminopropyltriethoxysilane to a mixed solution of 20 mL of anhydrous ethanol and 2 mL of deionized water, adjust the pH to 4-5, stir at room temperature for 30 min to hydrolyze the 3-aminopropyltriethoxysilane; add 2 g of nano zinc oxide to 100 mL of anhydrous ethanol, sonicate for 30 min to obtain a suspension of nano zinc oxide; add the hydrolyzed 3-aminopropyltriethoxysilane dropwise to the suspension of nano zinc oxide, react at 60 °C for 3 h, centrifuge, wash with anhydrous ethanol and deionized water in sequence, and dry in a 50 °C oven to obtain aminated nano zinc oxide; (3) 36.2 g of isophorone diisocyanate, 35.0 g of polytetrahydrofuran ether diol and dibutyltin dilaurate (catalyst) were added to a four-necked flask equipped with mechanical stirring, nitrogen protection and reflux condenser, and reacted at 80 °C for 2 h to obtain a fluorinated polyurethane prepolymer; 32.4 g of the fluorinated chain extender obtained in step 1), 5.4 g of 1,4-butanediol and tetrahydrofuran were added to the fluorinated polyurethane prepolymer, and the mixture was stirred and reacted at 80 °C for 2 h. Tetrahydrofuran was added to dilute the solid content of the fluorinated polyurethane to 30% to obtain a fluorinated polyurethane solution; (4) Add 2g of the aminated nano zinc oxide obtained in step 2) to 100mL of tetrahydrofuran, disperse it by ultrasonication for 30min, and then take 75mL and add it dropwise to 50mL of the fluorinated polyurethane solution obtained in step 3). Stir at 80℃ for 10min to obtain the fluorinated polyurethane nanocomposite solution. (5) Immerse the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 4), take out the polyester cable, air dry it naturally for 24 hours, and then put it into a 60℃ oven to dry to constant weight. (6) Repeat step 5) several times until the mass fraction of the fluorinated polyurethane nanocomposite coating in the polyester cable after coating is 20 wt%, thus obtaining the marine engineering polyester cable with the polyurethane nanocomposite coating. Coating adhesion test result: Level 2. (As can be seen from Comparative Example 6, the excessive amount of aminated nano zinc oxide ultimately leads to a decrease in coating adhesion to Level 2.) The test data above show that the polyester cables of Examples 1-3 of the present invention have significantly better resistance to ultraviolet radiation, seawater corrosion, and marine antifouling than those of Comparative Examples 1-6. Compared with Comparative Example 1, Comparative Example 2 showed a significant decrease in both water absorption and diatom adhesion rate, indicating that the polyurethane coating can effectively improve the resistance to seawater erosion and marine antifouling performance.

[0043] Compared with Comparative Example 2, Comparative Examples 3 and 4 showed a decrease in transmittance at 350 nm, and a significant decrease in water absorption and diatom adhesion rate, indicating that the introduction of fluorinated chain extenders into polyurethane effectively improved its UV resistance, seawater erosion resistance, and marine antifouling performance.

[0044] Compared to Comparative Examples 3 and 4, Comparative Example 5 showed a significant decrease in transmittance at 350 nm, an increase in water absorption, and a decrease in diatom adhesion. Compared to Comparative Example 5, Examples 1-3 showed a decrease in water absorption. Furthermore, with the same amount of zinc oxide, Examples 1-3 exhibited lower water absorption and diatom adhesion than Comparative Example 5, indicating that aminated zinc oxide significantly improves UV resistance, seawater corrosion resistance, and marine antifouling performance compared to unmodified zinc oxide. Moreover, Examples 1-3 maintained an adhesion rating of 0, superior to Comparative Example 6, suggesting that the amount of aminated zinc oxide added needs to be controlled within a reasonable range to ensure the adhesion between the coating and the cable substrate and prevent coating peeling.

[0045] In summary, this invention, through the synergistic effect of fluorinated polyurethane and aminated nano zinc oxide, combined with an optimized preparation process, enables polyester cables to simultaneously possess excellent UV resistance, seawater corrosion resistance, and marine antifouling properties, while also exhibiting strong coating adhesion, meeting the requirements for use in the marine engineering field.

[0046] The above embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall be applicable to the scope of protection of the present invention.

Claims

1. A polyester cable coated with a polyurethane nanocomposite coating, characterized in that: The surface of the polyester cable is coated with a composite coating of fluorinated polyurethane and aminated nano zinc oxide. The fluorinated polyurethane is mainly polymerized from diisocyanate, polyol, fluorinated chain extender and small molecule chain extender. The fluorinated chain extender is prepared by reacting 1-thioglycerol with 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl methacrylate, and its chemical structure is shown below: The aminated nano zinc oxide is prepared by modifying the surface of nano zinc oxide with an amino-containing silane coupling agent.

2. The polyester cable with a polyurethane nanocomposite coating according to claim 1, characterized in that: The molar ratio of the diisocyanate, polyol, fluorinated chain extender and small molecule chain extender is 16.3:3.5:3-6:9-6.

3. The polyester cable with a polyurethane nanocomposite coating according to claim 1, characterized in that: The diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, and cyclohexyl diisocyanate; the polyol is at least one of polypropylene glycol, polyoxypropylene polyol, and polytetrahydrofuran ether glycol; and the small molecule chain extender is at least one of 1,4-butanediol, ethylene glycol, and hexanediol.

4. The polyester cable with a polyurethane nanocomposite coating according to claim 1, characterized in that: The content of the aminated nano zinc oxide in the composite coating of fluorinated polyurethane and aminated nano zinc oxide is 1-2 wt%.

5. A method for preparing a polyester cable coated with a polyurethane nanocomposite coating as described in any one of claims 1-4, characterized in that, The method includes the following steps: Step 1) 1-Thioglycerol and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecylfluorooctyl methacrylate are reacted at a certain temperature to obtain a fluorinated chain extender. Step 2) The hydrolyzed 3-aminopropyltriethoxysilane is added dropwise to the nano zinc oxide suspension and reacted at a certain temperature to obtain aminated nano zinc oxide; Step 3) Under a nitrogen atmosphere, diisocyanate, polyol and catalyst are reacted at a certain temperature to obtain a prepolymer. The fluorinated chain extender, small molecule chain extender and tetrahydrofuran obtained in step 1) are added to the prepolymer, the reaction is continued, and tetrahydrofuran is added to dilute the solution to obtain a fluorinated polyurethane solution. Step 4) Disperse the aminated nano zinc oxide obtained in step 2) in tetrahydrofuran, and then add it dropwise to the fluorinated polyurethane solution obtained in step 3). Stir at a certain temperature until it is uniform and stable to obtain a fluorinated polyurethane nanocomposite solution. Step 5) After fully immersing the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in Step 4), remove it, air dry it, and then dry it to constant weight. Step 6) Repeat step 5) several times to obtain the polyester cable with polyurethane nanocomposite coating.

6. The method for preparing a polyester cable coated with a polyurethane nanocomposite coating according to claim 5, characterized in that: Step 1) specifically involves using triethylamine as a catalyst to add 1-thioglycerol, 3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluorooctyl methacrylate to tetrahydrofuran, and reacting at 30-40°C for 4-8 hours to obtain a fluorinated chain extender; wherein the molar ratio of 1-thioglycerol, 3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluorooctyl methacrylate, and triethylamine is 2:1:

2.

7. The method for preparing a polyester cable coated with a polyurethane nanocomposite coating according to claim 5, characterized in that: Step 2) specifically involves adding 3-aminopropyltriethoxysilane to a mixed solution of anhydrous ethanol and deionized water, adjusting the pH to 4-5, and stirring at room temperature for 20-40 min to hydrolyze the 3-aminopropyltriethoxysilane; adding nano-zinc oxide to anhydrous ethanol and sonicating for 20-40 min to obtain a suspension of nano-zinc oxide; adding the hydrolyzed 3-aminopropyltriethoxysilane solution dropwise to the suspension of nano-zinc oxide, reacting at 50-65℃ for 1-4 h, centrifuging, washing successively with anhydrous ethanol and deionized water, and drying to obtain aminated nano-zinc oxide.

8. The method for preparing a polyester cable coated with a polyurethane nanocomposite coating according to claim 5, characterized in that: Specifically, step 3) involves stirring diisocyanate, polyol, and catalyst at 65-85°C for 1-3 hours under a nitrogen atmosphere to obtain a prepolymer; adding the fluorinated chain extender, small molecule chain extender, and tetrahydrofuran obtained in step 1) to the prepolymer, and continuing to stir the reaction at 65-85°C for 1-3 hours; then adding tetrahydrofuran to dilute the solid content of the fluorinated polyurethane to 20-40% to obtain a fluorinated polyurethane solution.

9. The method for preparing a polyester cable coated with a polyurethane nanocomposite coating according to claim 5, characterized in that: Specifically, step 4) involves dispersing the aminated nano-zinc oxide obtained in step 2) in tetrahydrofuran, then adding it dropwise to the fluorinated polyurethane solution obtained in step 3), and stirring at 60-90℃ for 5-15 minutes to obtain a fluorinated polyurethane nanocomposite solution.

10. The method for preparing a polyester cable coated with a polyurethane nanocomposite coating according to claim 5, characterized in that: Step 5) specifically involves fully immersing the polyester cable in the fluorinated polyurethane nanocomposite solution obtained in step 4), removing the polyester cable, air-drying it naturally for 24-48 hours, and then transferring it to a 60-80℃ oven to dry to a constant weight.

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