A flame-retardant and seawater-resistant polyester cable and its preparation method

Abstract

This invention discloses a flame-retardant and seawater-resistant polyester cable and its preparation method. The method involves coating the surface of the polyester cable with a polyurethane coating that provides both flame retardancy and seawater resistance. The method involves reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether to obtain a phosphorus-containing flame-retardant chain extender; reacting diisocyanate, petroleum-based polyol, bio-oil-based polyol, a hydrophilic chain extender, a catalyst, a small molecule chain extender, and the phosphorus-containing flame-retardant chain extender to obtain a prepolymer; cooling and neutralizing the prepolymer, adding deionized water and stirring to remove acetone to obtain the flame-retardant and seawater-resistant polyurethane; immersing the polyester cable in the flame-retardant and seawater-resistant polyurethane, removing and drying it; repeating this process several times to obtain the flame-retardant and seawater-resistant polyester cable. The polyester cable of this invention possesses seawater resistance and flame retardancy, and the preparation method is simple, showing broad application prospects in marine engineering, shipping, and marine fisheries.

Description

Technical Field

[0001] This invention relates to a polyester cable and its preparation method, and more particularly to a flame-retardant and seawater-resistant polyester cable and its preparation method. Background Technology

[0002] Polyester cables are widely used in marine engineering, shipping, and fisheries due to their high strength, low elongation, and good flexibility. They play a crucial role in ensuring operational safety and efficiency, undertaking important tasks such as ship mooring, cargo handling, and securing offshore facilities. However, in the marine environment, the high salinity, strong corrosiveness, and complex chemicals of seawater continuously erode polyester cables. Prolonged exposure to such an environment damages the cable's fiber structure, drastically reduces its strength, and significantly shortens its service life. Simultaneously, fire safety is a significant concern. Polyester materials are inherently flammable; in the event of a fire on a ship or offshore platform, the polyester cable will burn rapidly, not only quickly destroying its own structure but also contributing to the spread of fire, posing a significant threat to life and property. Polyurethane materials possess excellent abrasion resistance, chemical corrosion resistance, and good flexibility, making them one of the commonly used coatings for polyester cables, as the coating can improve the seawater resistance of the polyester cable. However, polyurethane has low flame retardancy, resulting in lower flame retardancy for polyester cables coated with it. Therefore, when polyurethane is used as a coating for polyester cables, how to simultaneously achieve seawater resistance and flame retardancy is a pressing problem that needs to be solved. Summary of the Invention

[0003] To overcome the problems existing in the background art, the present invention provides a flame-retardant and seawater-resistant polyester cable and its preparation method. The preparation method of the present invention is simple, and the resulting polyester cable has good flame-retardant and seawater-resistant properties, and has broad application prospects in marine engineering, shipping, and marine fisheries.

[0004] To achieve the above objectives, the present invention involves coating the surface of a polyester cable with a flame-retardant and seawater-resistant polyurethane coating. The method involves reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether to obtain a phosphorus-containing flame-retardant chain extender; reacting diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, catalyst, small molecule chain extender, and phosphorus-containing flame-retardant chain extender to obtain a prepolymer; cooling and neutralizing the prepolymer, adding deionized water and stirring to remove acetone, resulting in a flame-retardant and seawater-resistant polyurethane; immersing the polyester cable in the flame-retardant and seawater-resistant polyurethane, removing and drying it; repeating this process several times to obtain a flame-retardant and seawater-resistant polyester cable.

[0005] More specifically, the specific technical solution adopted by the present invention to solve its technical problem is as follows:

[0006] I. A flame-retardant and seawater-resistant polyester cable:

[0007] The surface of the polyester cable is coated with a flame-retardant and seawater-resistant polyurethane coating, the chemical structural formula of which is shown below:

[0008]

[0009] Where n ranges from 30 to 40, the wavy line represents the repeating segment in the chemical structure of the polyurethane with flame retardant and seawater resistant functions, and NCO represents the isocyanate group.

[0010] The flame-retardant and seawater-resistant polyurethane is mainly polymerized from diisocyanate, petroleum-based polyol, bio-oil-based polyol, phosphorus-containing flame-retardant chain extender, small molecule chain extender, and hydrophilic chain extender. The mass ratio of diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, small molecule chain extender, phosphorus-containing flame-retardant chain extender, neutralizer, and catalyst is 45-55:35-45:5-10:8-10:1-5:5-20:5-10:0.04-0.06.

[0011] The phosphorus-containing flame-retardant chain extender, present in 1-15 wt% of flame-retardant and seawater-resistant polyurethane, is prepared from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether, and its chemical structure is shown below:

[0012]

[0013] The phosphorus-containing flame-retardant chain extender is obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether in a nitrogen atmosphere at a temperature range of 120-160℃ for 10-15 hours, followed by cooling to room temperature and purification by distillation.

[0014] The diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, and cyclohexyl diisocyanate.

[0015] The petroleum-based polyol is at least one of polypropylene glycol, polyoxypropylene polyol, and polytetrahydrofuran ether glycol.

[0016] The bio-oil-based polyol is at least one of castor oil, soybean oil, and flaxseed oil.

[0017] The small molecule chain extender is at least one of 1,4-butanediol, ethylene glycol, and hexanediol.

[0018] The hydrophilic chain extender is at least one of 2,2-dimethylolpropionic acid and 2,2-dimethylolbutyric acid.

[0019] II. A method for preparing a flame-retardant and seawater-resistant polyester cable, comprising the following steps:

[0020] Step 1) Under a nitrogen atmosphere, a phosphorus-containing flame-retardant chain extender is obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether.

[0021] Step 2) Under a nitrogen atmosphere, diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender and catalyst are reacted at a certain temperature. After heating, small molecule chain extender and phosphorus-containing flame-retardant chain extender obtained in step 1) and acetone are added in sequence, and the reaction continues to obtain prepolymer.

[0022] Step 3) After cooling and neutralizing the prepolymer obtained in Step 2), deionized water is added and stirred. Acetone is removed by rotary evaporation to obtain the polyurethane that has both flame retardant and seawater resistant functions.

[0023] Step 4) Thoroughly immerse the polyester cable in the flame-retardant and seawater-resistant polyurethane obtained in Step 3), remove the polyester cable, and dry it.

[0024] Step 5) Repeat step 4) several times to obtain the flame-retardant and seawater-resistant polyester cable.

[0025] Specifically, step 1) involves mixing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether in a molar ratio of 1.1:1 under a nitrogen atmosphere, stirring the mixture at 120-160°C for 10-15 hours, cooling it to room temperature, and purifying it by distillation to obtain a phosphorus-containing flame-retardant chain extender.

[0026] In step 2), diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender and catalyst are stirred and reacted at 65-85℃ for 1-3 hours. After heating to 75-90℃, small molecule chain extender and phosphorus-containing flame-retardant chain extender are added. Then, acetone is added to adjust the viscosity of the system and the reaction continues for 5-9 hours.

[0027] The catalyst is at least one of dibutyltin dilaurate and stannous octoate.

[0028] In step 3), the prepolymer is cooled to 35-50°C, neutralized with a neutralizing agent for 30-40 minutes, deionized water is added, and the mixture is stirred at 600-1000 r / min for 20-30 minutes; the neutralizing agent is at least one of triethylamine and triethanolamine.

[0029] The resulting flame-retardant and seawater-resistant polyurethane has a solid content of 25-35%.

[0030] In steps 2) and 3), the mass ratio of diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, small molecule chain extender, phosphorus-containing flame-retardant chain extender, neutralizer, and catalyst is 45-55:35-45:5-10:8-10:1-5:5-20:5-10:0.04-0.06.

[0031] In step 2), the amount of acetone added is 1-5 mL of acetone per 1 g of the whole mixture consisting of diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, small molecule chain extender, phosphorus-containing flame-retardant chain extender and catalyst.

[0032] The beneficial effects of this invention are:

[0033] The preparation method of this invention is simple, and the surface of the obtained polyester cable is coated with a polyurethane coating with flame retardant and seawater resistant functions. Petroleum-based polyol, bio-oil-based polyol, and phosphorus-containing flame retardant chain extender are introduced into the polyurethane molecular backbone. The phosphorus-containing flame retardant chain extender is formed by the reaction of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether.

[0034] The flame-retardant and seawater-resistant polyurethane coating of this invention combines the characteristic molecular structures of petroleum-based polyols, bio-oil-based polyols, and phosphorus-containing flame-retardant chain extenders, endowing polyester cables with excellent flame-retardant and seawater-resistant properties. Bio-oil-based polyols, as derivatives of natural bio-oils, exhibit excellent charring performance and low smoke release during combustion. The characteristic benzene ring structure and phosphorus element of the phosphorus-containing flame-retardant chain extender contribute to its good thermal decomposition stability and flame-retardant properties, improving charring efficiency and inhibiting melt dripping, thereby enhancing the flame-retardant performance of the polyester cable. The seawater resistance is mainly attributed to the penetration, bonding, and film-forming effects of the flame-retardant and seawater-resistant polyurethane on the polyester cable, as well as the hydrophobicity of organic groups such as urethane esters in the molecular structure of this type of polyurethane. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments.

[0036] The embodiments of the present invention are as follows:

[0037] In the following examples, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (97%), trimethylolpropane allyl ether (95%), isophorone diisocyanate (99%), polypropylene glycol 2000, castor oil (CP), 2,2-dimethylolpropionic acid (98%), dibutyltin dilaurate (95%), 1,4-butanediol (99.5%), triethylamine (99%), and polyester cable were commercially available materials.

[0038] Seawater wicking test method: Add 1ml of red ink to 30ml of artificial seawater, completely immerse the end of a 10cm long polyester cable, and record the water absorption length after 48h.

[0039] Example 1:

[0040] (1) Under a nitrogen atmosphere, 21.8 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 17.4 g of trimethylolpropane allyl ether were stirred at 150 °C for 12 h, cooled to room temperature, and purified by distillation to obtain a phosphorus-containing flame retardant chain extender.

[0041] (2) Under a nitrogen atmosphere, 10g of isophorone diisocyanate, 8g of polypropylene glycol 2000, 1.4g of castor oil, 1.7g of 2,2-dimethylolpropionic acid and 0.011g of dibutyltin dilaurate were stirred at 80°C for 2.5h. The system was heated to 85°C, and 0.8g of 1,4-butanediol and 1.2g of the phosphorus-containing flame retardant chain extender obtained in step 1) were added. 20mL of acetone was added, and the reaction was continued to obtain the prepolymer.

[0042] (3) Cool the prepolymer obtained in step 2) to 45°C, add 1.3g of triethylamine to neutralize for 40min, add 45mL of deionized water and stir for 30min, remove acetone by rotary evaporation to obtain the flame-retardant polyurethane, denoted as FRWPU5.

[0043] (4) Immerse the polyester cable in the FRWPU5 obtained in step 3), remove the polyester cable, and dry it;

[0044] (5) Repeat step 4) several times to make the mass fraction of FRWPU5 coating in the polyester cable after coating 30%, and obtain the flame retardant polyester cable, denoted as PET rope-FRWPU5.

[0045] The results of the seawater wicking test are shown in Table 1.

[0046] The UL-94 flame retardant performance test results are shown in Table 2.

[0047] Example 2:

[0048] (1) Under a nitrogen atmosphere, 21.8 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 17.4 g of trimethylolpropane allyl ether were stirred at 150 °C for 12 h, cooled to room temperature, and purified by distillation to obtain a phosphorus-containing flame retardant chain extender.

[0049] (2) Under a nitrogen atmosphere, 10g of isophorone diisocyanate, 8g of polypropylene glycol 2000, 1.4g of castor oil, 1.7g of 2,2-dimethylolpropionic acid and 0.011g of dibutyltin dilaurate were stirred at 80°C for 2.5h. The system was then heated to 85°C, and 0.5g of 1,4-butanediol and 2.5g of the phosphorus-containing flame retardant chain extender obtained in step 1) were added. 22mL of acetone was added, and the reaction was continued to obtain the prepolymer.

[0050] (3) Cool the prepolymer obtained in step 2) to 45°C, add 1.3g of triethylamine to neutralize for 40min, add 59mL of deionized water and stir for 30min, remove acetone by rotary evaporation to obtain the flame-retardant polyurethane, denoted as FRWPU10.

[0051] (4) Immerse the polyester cable in the FRWPU10 obtained in step 3), remove the polyester cable, and dry it;

[0052] (5) Repeat step 4) several times to make the mass fraction of FRWPU10 coating in the polyester cable after coating 30%, and obtain the flame-retardant polyester cable, denoted as PET rope-FRWPU10.

[0053] The results of the seawater wicking test are shown in Table 1.

[0054] The UL-94 flame retardant performance test results are shown in Table 2.

[0055] Example 3:

[0056] (1) Under a nitrogen atmosphere, 21.8 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 17.4 g of trimethylolpropane allyl ether were stirred at 150 °C for 12 h, cooled to room temperature, and purified by distillation to obtain a phosphorus-containing flame retardant chain extender.

[0057] (2) Under a nitrogen atmosphere, 10g of isophorone diisocyanate, 8g of polypropylene glycol 2000, 1.4g of castor oil, 1.7g of 2,2-dimethylolpropionic acid and 0.011g of dibutyltin dilaurate were stirred at 80°C for 2.5h. The system was heated to 85°C, and 0.2g of 1,4-butanediol and 3.9g of the phosphorus-containing flame retardant chain extender obtained in step 1) were added. 25mL of acetone was added, and the reaction was continued to obtain the prepolymer.

[0058] (3) Cool the prepolymer obtained in step 2) to 45°C, add 1.3g of triethylamine to neutralize for 40min, add 62mL of deionized water and stir for 30min, remove acetone by rotary evaporation, and obtain the phosphorus-containing flame-retardant waterborne polyurethane, denoted as FRWPU15.

[0059] (4) Immerse the polyester cable in the FRWPU15 obtained in step 3), remove the polyester cable, and dry it;

[0060] (5) Repeat step 4) several times to make the mass fraction of FRWPU15 coating in the polyester cable after coating 30%, and obtain the flame retardant polyester cable, denoted as PET rope-FRWPU15.

[0061] The results of the seawater wicking test are shown in Table 1.

[0062] The UL-94 flame retardant performance test results are shown in Table 2.

[0063] Comparative Example 1:

[0064] (1) Under a nitrogen atmosphere, 10g of isophorone diisocyanate, 8g of polypropylene glycol 2000, 1.4g of castor oil, 1.7g of 2,2-dimethylolpropionic acid and 0.011g of dibutyltin dilaurate were stirred at 80°C for 2.5h. The system was then heated to 85°C, 1.3g of 1,4-butanediol was added, and 20mL of acetone was added. The reaction was continued to obtain the prepolymer.

[0065] (2) Cool the prepolymer obtained in step 1) to 45°C, add 1.3g of triethylamine to neutralize for 40min, add 55mL of deionized water and stir for 30min, remove acetone by rotary evaporation to obtain the flame-retardant polyurethane, denoted as FRWPU.

[0066] (3) Immerse the polyester cable in the FRWPU obtained in step 2), remove the polyester cable, and dry it;

[0067] (4) Repeat step 3) several times to make the mass fraction of FRWPU coating in the polyester rope after coating 30%, and obtain the flame retardant polyester rope, denoted as PET rope-FRWPU.

[0068] The results of the seawater wicking test are shown in Table 1.

[0069] The UL-94 flame retardant performance test results are shown in Table 2.

[0070] Table 1: Results of Seawater-resistant wicking test

[0071] sample Cubic suction height (mm) blank sample 65 Comparative Example 1 12 Example 1 10 Example 2 15 Example 3 25

[0072] Table 2: UL-94 Flame Retardant Performance Test Results

[0073]

[0074] The blank sample was a pure polyester cable. Comparative Example 1 did not contain phosphorus-containing flame-retardant chain extender, while Examples 1, 2, and 3 contained phosphorus-containing flame-retardant chain extender. Seawater wicking tests showed that the wicking height of the blank sample after 48 hours was 65 mm. Compared to the blank sample, the wicking heights of the comparative and examples were significantly lower. While the wicking height increased with increasing mass fraction of the phosphorus-containing flame-retardant chain extender in the polyurethane, it was still significantly lower than that of the blank sample.

[0075] The UL-94 flame retardant performance test results for the blank sample and Comparative Example 1 show that although the coating of Comparative Example 1 improved seawater resistance, it reduced flame retardant performance. However, with the introduction and increased dosage of phosphorus-containing flame retardant chain extenders, the flame retardant performance gradually improved.

[0076] As can be seen from the comparison, the polyester cable of the present invention has seawater resistance and flame retardant properties, and the preparation method is simple. It has broad application prospects in marine engineering, shipping, marine fisheries and other fields.

[0077] 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 method for preparing a flame-retardant and seawater-resistant polyester cable, characterized in that, The surface of the polyester cable is coated with a flame-retardant and seawater-resistant polyurethane coating, the chemical structural formula of which is shown below: Where n ranges from 30 to 40, the wavy line represents the repeating segment in the chemical structure of the polyurethane with flame retardant and seawater resistant functions, and NCO represents the isocyanate group. The method includes the following steps: Step 1) Under a nitrogen atmosphere, a phosphorus-containing flame-retardant chain extender is obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether. Step 2) Under a nitrogen atmosphere, diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender and catalyst are reacted at a certain temperature. After heating, small molecule chain extender and phosphorus-containing flame-retardant chain extender obtained in step 1) and acetone are added in sequence, and the reaction continues to obtain prepolymer. Step 3) After cooling and neutralizing the prepolymer obtained in Step 2), deionized water is added and stirred. Acetone is removed by rotary evaporation to obtain the flame-retardant and seawater-resistant polyurethane. Step 4) Thoroughly immerse the polyester cable in the flame-retardant and seawater-resistant polyurethane obtained in Step 3), remove the polyester cable, and dry it. Step 5) Repeat step 4) several times to obtain the flame-retardant and seawater-resistant polyester cable.

2. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 1, characterized in that: The flame-retardant and seawater-resistant polyurethane coating is mainly composed of diisocyanate, petroleum-based polyol, bio-oil-based polyol, phosphorus-containing flame-retardant chain extender, small molecule chain extender, and hydrophilic chain extender. The mass ratio of diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, small molecule chain extender, phosphorus-containing flame-retardant chain extender, neutralizer, and catalyst is 45-55:35-45:5-10:8-10:1-5:5-20:5-10:0.04-0.

06.

3. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 2, characterized in that: The phosphorus-containing flame-retardant chain extender, present in 1-15 wt% of flame-retardant and seawater-resistant polyurethane, is prepared from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether, and its chemical structure is shown below:

4. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 3, characterized in that: The phosphorus-containing flame-retardant chain extender is obtained by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether in a nitrogen atmosphere at a temperature range of 120-160°C, followed by cooling to room temperature and purification by distillation.

5. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 2, characterized in that: The diisocyanate is at least one of isophorone diisocyanate, hexamethylene diisocyanate, and cyclohexyl diisocyanate; The petroleum-based polyol is at least one of polypropylene glycol, polyoxypropylene polyol, and polytetrahydrofuran ether glycol. The bio-oil-based polyol is at least one of castor oil, soybean oil, and flaxseed oil; The small molecule chain extender is at least one of 1,4-butanediol, ethylene glycol, and hexanediol; The hydrophilic chain extender is at least one of 2,2-dimethylolpropionic acid and 2,2-dimethylolbutyric acid.

6. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 1, characterized in that: Specifically, step 1) involves mixing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and trimethylolpropane allyl ether in a molar ratio of 1.1:1 under a nitrogen atmosphere, stirring the mixture at 120-160°C for 10-15 hours, cooling it to room temperature, and purifying it by distillation to obtain a phosphorus-containing flame-retardant chain extender.

7. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 1, characterized in that: In step 2), diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender and catalyst are stirred and reacted at 65-85℃ for 1-3 hours. After heating to 75-90℃, small molecule chain extender and phosphorus-containing flame-retardant chain extender are added. Then acetone is added and the reaction continues for 5-9 hours.

8. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 1, characterized in that: In step 3), the prepolymer is cooled to 35-50°C, neutralized with a neutralizing agent for 30-40 minutes, deionized water is added, and the mixture is stirred at 600-1000 r / min for 20-30 minutes; the neutralizing agent is at least one of triethylamine and triethanolamine.

9. The method for preparing a flame-retardant and seawater-resistant polyester cable according to claim 1, characterized in that: In steps 2) and 3), the mass ratio of diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, small molecule chain extender, phosphorus-containing flame-retardant chain extender, neutralizer, and catalyst is: 45-55∶35-45∶5-10∶8-10∶1-5∶5-20∶5-10∶0.04-0.06; In step 2), the amount of acetone added is 1-5 mL of acetone per 1 g of the whole mixture consisting of diisocyanate, petroleum-based polyol, bio-oil-based polyol, hydrophilic chain extender, small molecule chain extender, phosphorus-containing flame-retardant chain extender and catalyst.

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