Chlorine-resistant wear-resistant waterproof fabric and preparation method thereof

Abstract

The invention belongs to the field of functional textile materials, and particularly relates to a chlorine-resistant wear-resistant waterproof fabric and a preparation method thereof. The fabric is prepared from the following raw materials in parts by weight: 40 to 70 parts of modified polyurethane elastomer, 20 to 50 parts of fluorine alkene urea alkyl ester, 2 to 6 parts of amino silane, 1 to 3 parts of fluorine-containing surfactant, 1 to 4 parts of cross-linking curing agent and 0.5 to 1.5 parts of flatting agent. A fluorine-containing urea alkyl ester and amino silane cross-linking system is introduced, and a chitosan grafted polyurethane structure with hydrophilicity and flexibility is combined, so that a compact protective coating with slow-release elasticity is constructed, and chlorine resistance, wear resistance and water resistance are remarkably improved. The material has excellent film-forming property and is suitable for complex working conditions of long-term water immersion and frequent friction. The prepared fabric has excellent structural stability and weather resistance, can be widely applied to the fields of swimsuits, outdoor protective clothing and industrial filter cloth, and has good market popularization value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional textile materials, in particular to a chlorine-resistant and wear-resistant waterproof fabric and a preparation method thereof. BACKGROUND

[0002] Functional waterproof fabric has a wide range of applications in swimwear, diving suits, outdoor protective clothing, and water operation equipment, etc. With the complexity of the use environment, higher requirements are put forward for the waterproofness, chlorine resistance, wear resistance and flexibility of the fabric. However, the existing waterproof fabric generally has the technical problems of poor durability, unstable structure and decay of protective performance, especially under extreme working conditions such as high chlorine, high humidity and high frequency friction, the coating is prone to aging, peeling or failure, which cannot meet the long-term demand.

[0003] Traditional waterproof fabric mostly uses polyurethane or polyvinyl chloride coating. These coatings are usually applied on the surface of the fabric by means of blade coating or dip coating, forming a dense film to block the penetration of water. Although polyurethane materials have certain flexibility and initial waterproof performance, their stability in chlorine-containing environment is poor, and the molecular structure is easily damaged by oxidizing media such as hypochlorous acid, leading to coating embrittlement, fracture and even delamination. The interfacial adhesion between the coating and the base fabric is weak, and after repeated washing, folding or friction, it is easy to produce hollowing, edge lifting and other failure problems, which seriously affects the service life and protective effect.

[0004] In the prior art, fluorocarbon waterproofing agents, silane coupling agents or inorganic nanoparticles have also been tried to modify in order to improve the surface hydrophobicity and interfacial adhesion, but such modified materials often have the problems of single function, poor system stability, and insufficient compatibility with the base material. For example, fluorocarbon compounds have excellent hydrophobic properties, but they are easily degraded in a chlorinated environment, and their sustainable application prospect is questioned due to environmental regulations. Traditional polyurethane materials lack cross-linking barrier structures, and the surface of the waterproof coating is mostly a flat and dense film, which is difficult to form an effective micro-rough structure, which is not conducive to the construction of super-hydrophobic effect and self-cleaning performance of the protective layer.

[0005] Therefore, there is an urgent need to develop a new protective coating material with excellent comprehensive performance, which can construct a stable, chlorine-resistant and wear-resistant flexible protective layer on the surface of the fabric, and realize the synergistic regulation of multiple functions, thereby improving the protective performance and service life of the fabric in a chlorine-containing environment. SUMMARY

[0006] To overcome the problems mentioned in the background, the present invention aims to provide a chlorine-resistant, abrasion-resistant, and waterproof fabric and its preparation method. A composite protective coating composed of a modified polyurethane elastomer and a fluorourea ester is constructed on the fabric surface. An aminosilane coupling agent enhances interfacial adhesion, a fluorinated surfactant regulates hydrophobic properties, and a crosslinking curing agent and a leveling agent are introduced to improve coating uniformity and durability, forming a flexible and dense crosslinked protective structure. The modified polyurethane elastomer incorporates flexible siloxane segments and chitosan graft structures to improve the coating's flexibility and hydrolysis resistance. The fluorourea ester, as a functional small molecule filler, provides a three-functional structure of hydrophobic fluorine groups, chlorine-resistant urea groups, and crosslinked alkenyl groups, further enhancing the coating's chemical corrosion resistance and micro-roughness. Through the above structural design and component synergy, the fabric exhibits excellent chlorine resistance, abrasion resistance, and waterproof performance. The coating has high stability and strong adhesion, making it suitable for long-term use in the preparation of functional textiles for harsh conditions such as swimming pools, disinfection, and high humidity.

[0007] The objective of this invention can be achieved through the following technical solutions: A chlorine-resistant, abrasion-resistant, and waterproof fabric comprises the following raw materials in parts by weight: 40-70 parts of modified polyurethane elastomer, 20-50 parts of fluorourea ester, 2-6 parts of aminosilane, 1-3 parts of fluorinated surfactant, 1-4 parts of crosslinking curing agent, and 0.5-1.5 parts of leveling agent.

[0008] Optionally, the modified polyurethane elastomer comprises the following raw materials in parts by weight: 20-35 parts of polyadipate glycol, 15-25 parts of isophorone diisocyanate, 5-10 parts of hydroxyl-terminated polydimethylsiloxane, 3-6 parts of polyethylene glycol, 2-6 parts of grafted chitosan, 1-4 parts of dimethylolpropionic acid, 0.5-1.5 parts of triethylamine, 0.1-0.3 parts of dibutyltin dilaurate, and 10-20 parts of deionized water.

[0009] Optionally, the fluorourea ester is synthesized from the following raw materials in parts by weight: 5-12 parts of 3,3,3-trifluoroacrylic acid, 4-10 parts of isobutyl isocyanate, 3-8 parts of aminoethanol, 5-12 parts of nonanol, 0.1-0.5 parts of p-toluenesulfonic acid catalyst, and 10-25 parts of ethyl acetate.

[0010] Optionally, the fluorinated surfactant is a mixture of potassium perfluorohexyl sulfonate and polyoxyethylene (20) cetyl alcohol in a mass ratio of 1:1; the crosslinking curing agent is a mixture of hexamethylene diisocyanate trimer and 2-hydroxyethyl acrylate in a mass ratio of 3:1; and the leveling agent is a mixture of polyether-modified polydimethylsiloxane and isopropanol in a mass ratio of 4:1.

[0011] Optionally, the method for preparing the modified polyurethane elastomer includes the following steps: (1) Add polyadipate glycol, polyethylene glycol and hydroxyl-terminated polydimethylsiloxane to a reaction vessel, preheat and dissolve them under stirring to form a mixed polyol component; (2) Cool down to 60-70℃, add isophorone diisocyanate dropwise, and continue the reaction for 2-3 hours to obtain the terminal isocyanate prepolymer; (3) Add dimethylolpropionic acid and continue the reaction for 1-2 hours to introduce a hydrophilic carboxyl group structure, then cool; (4) Triethylamine is added dropwise under stirring to neutralize the carboxyl groups and form a water-soluble structure; (5) Slowly add deionized water to emulsify and disperse, and obtain a uniform waterborne polyurethane emulsion; (6) Add grafted chitosan to the aqueous polyurethane emulsion to complete the end grafting reaction and obtain the modified polyurethane elastomer dispersion.

[0012] Optionally, the preheating temperature in step (1) is 80-90°C; the cooling temperature in step (3) is 30-40°C; and the reaction conditions for the end grafting reaction in step (6) are stirring at 40-60°C for 1-2 hours.

[0013] Optionally, the preparation method of fluorourea ester includes the following steps: (a) 3,3,3-trifluoroacrylic acid and isobutyl isocyanate were added to a reaction vessel and stirred to generate an isocyanate intermediate; (b) Add aminoethanol to the isocyanate intermediate to generate a reaction solution containing a urea group; (c) Nonanol is added as an esterifying agent to the reaction solution of the intermediate containing the urea group, and fluorourea ester is generated under the catalysis of p-toluenesulfonic acid; (d) After the reaction is complete, ethyl acetate is added for dilution, the mixture is stirred evenly, cooled, filtered, and the solvent is removed under vacuum to obtain the fluorourea ester product.

[0014] Optionally, in step (a), the reaction conditions in the reactor are 50-60°C for 2-3 hours; in step (b), the reaction conditions are 40-50°C for 1-2 hours; and in step (c), the reaction conditions are 60-70°C for 1-2 hours.

[0015] Optionally, a chlorine-resistant, abrasion-resistant, and waterproof fabric and its preparation method include the following steps: S1, the modified polyurethane elastomer, fluorourea ester, aminosilane, fluorinated surfactant, crosslinking curing agent and leveling agent are mixed and mixed evenly under stirring conditions to obtain the protective coating liquid. S2, apply the protective coating liquid evenly to the surface of the polyester fabric by dip coating to form a preliminary wet film; S3. The coated fabric is initially dried at 60-80℃ and then heat-cured at 130-150℃ for 10-15 minutes to form a dense and uniform protective coating, resulting in a chlorine-resistant, wear-resistant, and waterproof fabric.

[0016] The beneficial effects of this invention are: This invention achieves a significant improvement in chlorine resistance, water resistance, and abrasion resistance by constructing a protective coating system with a multifunctional synergistic structure. The modified polyurethane elastomer incorporates flexible siloxane segments and chitosan grafted structures, enhancing the coating's adhesion to fabrics while maintaining good flexibility. This improves interfacial stability and hydrolysis resistance, preventing coating cracking and peeling caused by repeated washing, bending, or stretching.

[0017] Fluoroalkyl urea, as a uniquely structured functional small molecule, contains fluorinated alkenyl, urea, and alkyl groups simultaneously, exhibiting hydrophobicity, chlorine resistance, and crosslinking reactivity. During heat treatment, it is uniformly dispersed within a polyurethane matrix, inducing the formation of micro- and nano-scale surface rough structures. This facilitates the construction of hydrophobic protrusions and enhances surface tension differences, significantly improving the coating's water repellency and self-cleaning properties.

[0018] This invention, through the synergistic ratio of functional components and the gradient construction of coating structure, enables the resulting protective fabric to maintain excellent structural stability and protective performance in chlorine-containing, high-humidity, and high-friction environments, making it suitable for various textile applications with high requirements for waterproofness, chlorine resistance, and durability. Attached Figure Description

[0019] The invention will now be further described with reference to the accompanying drawings.

[0020] Figure 1 Comparison of infrared spectra of ungrafted waterborne polyurethane coating and chlorine-resistant and abrasion-resistant waterproof fabric; Figure 2 Scanning electron microscope image of chlorine-resistant, abrasion-resistant, and waterproof fabric; Figure 3 A bar chart comparing the performance of chlorine-resistant, abrasion-resistant, and waterproof fabrics with different formulation ratios. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments. However, the present invention is not limited to the following embodiments. Equivalent adjustments made without departing from the spirit and essence of the present invention should also be considered to fall within the protection scope of the present invention.

[0022] Example 1: Verify the film-forming quality and protective performance of coatings with a combination of high-content fluorourea ester and modified polyurethane.

[0023] Preparation steps: (1) Preparation of modified polyurethane elastomer: 30 parts of polyadipate glycol, 5 parts of polyethylene glycol, and 8 parts of hydroxyl-terminated polydimethylsiloxane were added to a reaction vessel and stirred at 85°C to dissolve and form a uniform polyol system; the temperature was lowered to 65°C, and 22 parts of isophorone diisocyanate were added dropwise, and the reaction was carried out for 2.5 hours to form a prepolymer with terminal isocyanate groups; 3.5 parts of dimethylolpropionic acid were added, and the reaction was continued for 1.5 hours to introduce carboxyl structure, and the reaction system was cooled to 35°C; 1.2 parts of triethylamine were added dropwise for neutralization, and then 15 parts of deionized water were slowly added to form a milky white uniform emulsion; 5 parts of grafted chitosan were added, and the mixture was stirred at 40°C for 1.5 hours to obtain a modified polyurethane elastomer dispersion; (2) Preparation of fluorourea ester: 10 parts of 3,3,3-trifluoroacrylate and 8 parts of isobutyl isocyanate were added to the reaction vessel and reacted at 55°C for 2.5 hours; 6 parts of aminoethanol were added and reacted at 45°C for 1.5 hours; 10 parts of nonanol were added and esterified at 65°C for 1.5 hours under the catalysis of p-toluenesulfonic acid; 20 parts of ethyl acetate were added for dilution, stirred evenly, cooled, filtered, and vacuum desolventized to obtain a viscous liquid of fluorourea ester; (3) Preparation of waterproof fabric: 60 parts of modified polyurethane elastomer dispersion, 45 parts of fluorourea ester, 5 parts of aminosilane, 2.5 parts of fluorinated surfactant, 3.5 parts of crosslinking curing agent and 1 part of leveling agent were mixed and stirred for 30 minutes; the mixture was applied to polyester fabric by dip coating, dried at 60°C for 10 minutes, and then heat-cured at 140°C for 12 minutes to obtain the sample of Example 1.

[0024] Example 2: By screening the intermediate ratios of each component, the optimal process combination for coating performance is obtained.

[0025] like Figure 1As shown in the infrared spectra, significant changes in the functional group composition of the samples before and after modification are evident. The ungrafted waterborne polyurethane coating exhibits a distinct –N=C=O absorption peak at 2270 cm⁻¹, indicating the presence of numerous unreacted isocyanate groups in the system. However, this absorption peak completely disappears in the modified chlorine-resistant and abrasion-resistant waterproof fabric sample, indicating that the isocyanate groups have completely reacted with the hydroxyl and amino groups in the system, forming a new cross-linked structure. In the chlorine-resistant and abrasion-resistant waterproof fabric sample, a distinct –NH–C=O urea group characteristic absorption peak appears in the 1680–1650 cm⁻¹ region, proving that the urea structure has been successfully generated and embedded in the polyurethane main chain or side chain, effectively enhancing the material's polarity and structural density. A series of strong absorption peaks appear in the 800–840 cm⁻¹ range of the chlorine-resistant and abrasion-resistant waterproof fabric sample. These peaks belong to the symmetric and asymmetric stretching vibration characteristics of the C–F bond, indicating the large-scale introduction and uniform distribution of fluorine-containing functional groups. Based on the introduction pathway of fluorourea ester and fluorinated surfactant, a stable fluorinated structure was confirmed to have formed in the material. This not only improves the surface hydrophobicity but also enhances resistance to oxidizing media such as hypochlorous acid. In summary, the integrity of the prepolymerization reaction, the formation of the urea group structure, and the successful introduction of the fluorinated structure were verified, indicating that the waterproof fabric achieves high density and multifunctional synergistic construction at the molecular level, providing important structural basis for its excellent chlorine resistance, abrasion resistance, and waterproofness.

[0026] like Figure 2 As shown in the figure, this is a scanning electron microscope image of the chlorine-resistant, abrasion-resistant, and waterproof fabric obtained by coating and curing in this embodiment. It can be observed from the image that the protective coating surface exhibits a typical multi-block dense cross-linked structure, while also uniformly distributing a large number of spherical to hemispherical micro-clusters, forming a typical rough surface morphology.

[0027] Preparation steps: (1) Preparation of modified polyurethane elastomer: 28 parts of polyadipate glycol, 4 parts of polyethylene glycol, and 7 parts of hydroxyl-terminated polydimethylsiloxane were added to a reaction vessel and stirred at 85°C to form a polyol system; the temperature was lowered to 65°C, 20 parts of isophorone diisocyanate were added, and the reaction was carried out for 2.5 hours; 2.5 parts of dimethylolpropionic acid were added and the reaction was continued for 1.5 hours, and the temperature was cooled to 35°C; 1 part of triethylamine was added dropwise to neutralize, and 13 parts of deionized water were slowly added to obtain a polyurethane emulsion; 4 parts of grafted chitosan were added, and the mixture was stirred at 50°C for 1 hour to obtain the modified polyurethane elastomer; (2) Preparation of fluorourea ester: 8 parts of 3,3,3-trifluoroacrylate and 6 parts of isobutyl isocyanate were reacted at 55°C for 2.5 hours; 5 parts of aminoethanol were added and reacted at 45°C for 1.5 hours; then 8 parts of nonanol were added and esterified at 65°C for 1.5 hours under the catalysis of p-toluenesulfonic acid; 15 parts of ethyl acetate were added, stirred, cooled, filtered, and the solvent was removed to obtain the finished product; (3) Preparation of waterproof fabric: 55 parts of modified polyurethane elastomer dispersion, 35 parts of fluorourea ester, 4 parts of aminosilane, 2 parts of fluorinated surfactant, 2.5 parts of crosslinking curing agent and 0.8 parts of leveling agent were mixed and stirred evenly; the polyester fabric was treated by dip coating, the drying temperature was 70℃, the thermosetting temperature was 140℃, and the heat was kept for 12 minutes to obtain the sample of Example 2.

[0028] Example 3: Verify the basic film-forming and protective capabilities of the material at low component addition levels.

[0029] Preparation steps: (1) Preparation of modified polyurethane elastomer: 22 parts of polyadipate glycol, 3 parts of polyethylene glycol and 5 parts of hydroxyl-terminated polydimethylsiloxane were added to a four-necked reactor equipped with a stirrer and stirred and heated at 85°C for 30 minutes to form a uniform polyol mixture system; the temperature was lowered to 65°C and 16 parts of isophorone diisocyanate were slowly added dropwise, and the reaction was maintained at a constant temperature and stirred for 2 hours to form an isocyanate-terminated prepolymer; 1.5 parts of dimethylolpropionic acid were added and reacted for 1 hour to introduce a carboxyl hydrophilic structure; after the system was cooled to 35°C, 0.8 parts of triethylamine were added dropwise for neutralization and reacted for 30 minutes; 12 parts of deionized water were slowly added dropwise under stirring to emulsify and disperse, forming a uniform aqueous polyurethane emulsion; 3 parts of grafted chitosan were added to the emulsion and stirred at 50°C for 1 hour to complete the end-group grafting reaction and obtain a modified polyurethane elastomer dispersion; (2) Preparation of fluorourea ester: 6 parts of 3,3,3-trifluoroacrylate and 5 parts of isobutyl isocyanate were added to a dry reaction vessel and stirred at 55°C for 2 hours to generate an isocyanate intermediate; 4 parts of aminoethanol were added and the reaction temperature was controlled at 45°C and the reaction was continued for 1.5 hours to generate an intermediate containing a urea group structure; then 6 parts of nonanol were added and esterified at 65°C for 1.5 hours under the catalysis of 0.2 parts of p-toluenesulfonic acid to form the main structure of fluorourea ester; 12 parts of ethyl acetate were added for dilution, stirred evenly and cooled to room temperature, impurities were removed by filtration, and the solvent was removed under vacuum to finally obtain a light yellow transparent viscous liquid of fluorourea ester; (3) Preparation of waterproof fabric: 45 parts of the modified polyurethane elastomer dispersion prepared above were mixed with 25 parts of fluorourea ester, and 2.5 parts of aminosilane, 1.5 parts of fluorinated surfactant, 1.5 parts of crosslinking curing agent and 0.6 parts of leveling agent were added in sequence. The mixture was stirred evenly at room temperature for 30 minutes to obtain a protective coating liquid. The polyester base fabric was cut into 200mm × 200mm samples, and the coating liquid was evenly coated on the surface by dip coating method. The samples were placed in a 70℃ forced-air drying oven and dried for 10 minutes. Then the samples were transferred to a hot press and heat-cured at 130℃ for 12 minutes to form a dense and continuous composite protective coating, which is the sample of Example 3.

[0030] Comparative Example 1 (without fluorourea esters) This was used to compare and verify the changes in the coating's water resistance and chlorine resistance under conditions without fluoroolefin urea ester.

[0031] Preparation steps: (1) Preparation of modified polyurethane elastomer: 28 parts of polyadipate glycol, 4 parts of polyethylene glycol, and 7 parts of hydroxyl-terminated polydimethylsiloxane were added to a reaction vessel and stirred at 85°C for 30 minutes to form a uniform polyol mixture; the temperature was lowered to 65°C, and 20 parts of isophorone diisocyanate were slowly added dropwise, and the reaction was continued to be stirred for 2.5 hours to obtain a terminal isocyanate prepolymer; 2.5 parts of dimethylolpropionic acid were added, and the reaction was maintained at 65°C for 1.5 hours to introduce a carboxyl structure; the system was cooled to 35°C, and 1 part of triethylamine was added dropwise for neutralization; 13 parts of deionized water were slowly added under stirring conditions to obtain a uniform aqueous polyurethane emulsion; 4 parts of grafted chitosan were added, and the reaction was continued at 50°C for 1 hour to complete the end grafting reaction and obtain a modified polyurethane elastomer dispersion; (2) Preparation of waterproof fabric: Weigh 55 parts of the modified polyurethane elastomer dispersion prepared above, add 4 parts of aminosilane, 2 parts of fluorinated surfactant, 2.5 parts of crosslinking curing agent and 0.8 parts of leveling agent, stir evenly for 30 minutes to obtain a protective coating mixture; do not add fluorourea ester component; apply the mixture evenly to the surface of polyester fabric by dip coating; dry the coated fabric at 70°C for 10 minutes, and then heat cure at 140°C for 12 minutes to obtain the comparative example 1 sample.

[0032] Comparative Example 2 (The modified polyurethane elastomer was replaced with ordinary waterborne polyurethane) This was used to compare and verify the performance differences between modified and unmodified polyurethane in terms of chlorine adhesion resistance and structural stability.

[0033] Preparation steps: (1) Substitution of ordinary waterborne polyurethane: Use commercially available ordinary waterborne polyurethane emulsion (40% solid content, without chitosan grafting and siloxane segment modification), take 55 parts of equal mass as the main matrix; no pre-reaction and dispersion treatment is required, and it can be used directly. (2) Preparation of fluorourea ester: 8 parts of 3,3,3-trifluoroacrylate and 6 parts of isobutyl isocyanate were added to the reaction vessel and stirred at 55°C for 2.5 hours to generate an isocyanate intermediate; 5 parts of aminoethanol were added and the reaction was continued at 45°C for 1.5 hours; 8 parts of nonanol were added and esterified at 65°C for 1.5 hours under the catalysis of p-toluenesulfonic acid; 15 parts of ethyl acetate were added for dilution, stirred evenly, cooled, filtered, and desolventized to obtain a viscous liquid of fluorourea ester; (3) Preparation of waterproof fabric: 55 parts of ordinary waterborne polyurethane emulsion, 35 parts of fluorourea ester, 4 parts of aminosilane, 2 parts of fluorinated surfactant, 2.5 parts of crosslinking curing agent and 0.8 parts of leveling agent were added to a mixing tank in sequence and stirred evenly for 30 minutes to obtain a protective coating liquid; the coating was evenly applied to the surface of polyester fabric by dip coating; the coated fabric was dried at 70℃ for 10 minutes and then heat-cured at 140℃ for 12 minutes to obtain the comparative example 2 sample.

[0034] Performance testing Chlorine resistance test method This method is used to evaluate the chemical stability and coating integrity of fabrics in chlorine-containing environments. The sample size is 100mm × 100mm. According to GB / T 8431-2019, the sample is immersed in a 10% sodium hypochlorite solution at 40℃ for 72 hours. After immersion, the sample is rinsed with deionized water and dried. The surface of the fabric coating is observed for changes such as peeling, cracking, flaking, or discoloration, which serve as the basis for determining chlorine resistance.

[0035] Waterproofing test method This test is used to evaluate the water-repellent ability of fabrics under pressure. According to GB / T 4744-2013, the sample is fixed on a hydrostatic tester with the test side facing the water surface. Water pressure is continuously applied at an upward rate of 10 cmH2O / min, and the pressure value (unit: mmH2O) when a water droplet first penetrates the back of the sample is recorded. Each sample is tested three times, and the average value is taken as the hydrostatic pressure result. A higher value indicates better waterproof performance.

[0036] Abrasion resistance test method This test was used to assess the structural integrity of fabric coatings under frictional loads. Following GB / T 21196.2-2007, a Martindale abrasion tester was employed, using standard wool fabric as the friction medium. The sample was subjected to circumferential reciprocating friction under a pressure of 9 kPa. The test was set to 5000 cycles. After the test, the coating surface was observed for wear, peeling, or damage, and the cycle number at which damage occurred was recorded to evaluate its abrasion resistance rating.

[0037] Adhesion test method This method is used to evaluate the adhesion strength between the protective coating and the fabric substrate. Following GB / T 9286-2021, dried samples are cut into 100mm × 100mm pieces. An 11×11 cross-hatching tool is used to create a 1mm wide grid on the coating surface. 3M tape is then applied and quickly peeled off vertically. The number of peel marks is checked, and the adhesion is graded from 0 to 5 (0 being the best and 5 the worst) according to the standard.

[0038] Flexibility testing methods This test assesses the structural integrity and flexibility retention of fabrics during repeated folding or dynamic bending. Following GB / T 18318.1-2009, the sample is folded and subjected to a standard weight for 10 minutes. After removal, it is allowed to stand for 5 minutes, and the recovery angle is measured; a larger angle indicates better flexibility. Additionally, the sample is manually folded 30 times repeatedly, and the presence of cracks, breaks, or peeling in the coating is observed as a comprehensive evaluation index of flexibility. Table 1 compares the performance test results of chlorine-resistant, abrasion-resistant, and waterproof fabrics.

[0039]

[0040] like Figure 3 As shown in Table 1, by comparing and analyzing the performance test results of Examples 1-3 and Comparative Examples 1-2, it can be clearly seen that the modified polyurethane elastomer and fluorourea alkyl ester composite system designed in this invention has significant advantages in terms of structural stability, protective function and coating durability, and exhibits a good synergistic enhancement effect among the core performance indicators.

[0041] Regarding waterproof performance, using hydrostatic pressure as the evaluation index, Example 2 achieved 3500 mmH2O, significantly higher than Comparative Example 1 (1800 mmH2O) and Comparative Example 2 (2200 mmH2O), demonstrating that the coating synergistically constructed from fluoroolefin ester and modified polyurethane in this invention can form a dense, highly hydrophobic microstructure surface. This microstructure surface consists of a spiky rough layer induced by fluorine groups, exhibiting water-repellent behavior similar to the "lotus effect," effectively preventing liquid penetration under water pressure. The balance between the flexible siloxane segments and hydrophilic / hydrophobic distribution in the modified polyurethane backbone also contributes to the self-adjusting distribution of the coating, resulting in better adhesion, no pinholes, and no microcracks.

[0042] Regarding chlorine resistance, Examples 1 and 2 remained unchanged after immersion in sodium hypochlorite, indicating that the coating system possesses excellent resistance to oxidation and corrosion. The fluorinated alkenyl structure in the fluoroalkenyl ester exhibits natural chemical inertness to chlorine oxides, forming a protective barrier at the molecular level to prevent reactive chloride ions from damaging the main chain. Simultaneously, the urea and alkenyl groups participate in cross-linking reactions, further strengthening intermolecular hydrogen bonds and the spatial network structure, reducing the degradation rate of the coating under oxidative stress. In contrast, Comparative Example 1 lacks the participation of the fluoroalkenyl ester, relying solely on the polyurethane emulsion itself, which is insufficient to resist oxidative damage in chlorine water, leading to surface blistering and peeling, severely affecting appearance and function.

[0043] Regarding wear resistance, Example 2 achieved 8000 Martindale wear cycles, significantly higher than Comparative Example 1's 4100 cycles and Comparative Example 2's 4500 cycles, indicating that the modified polyurethane network structure, while maintaining flexibility, also provides excellent resistance to mechanical damage. The introduction of siloxane segments gives the coating a certain energy buffering capacity, absorbing some frictional stress, while the cross-linked network formed by fluoroolefin urethane helps improve overall shear resistance and microstructural integrity.

[0044] Regarding adhesion, both Examples 1 and 2 achieved a grade of 0, indicating a strong bond between the coating and the fabric substrate, with no peeling in the cross-cut areas. This effect is mainly attributed to three factors: first, the chitosan grafting structure introduces multiple amino polar sites to the polyurethane ends, which can form hydrogen bonds or complex bonds with the fabric fiber surface; second, the aminosilane acts as a bridge, undergoing silanol condensation reactions with hydroxyl / amine groups at the interface; and third, the urea group structure in the fluorourea ester also participates in the polar forces between the coating and the fabric, enhancing the interlayer bonding stability. Comparative Example 2, which did not use grafted chitosan or siloxane-modified polyurethane, had an adhesion grade of only 2, with significant coating peeling.

[0045] Regarding flexibility, using the crease recovery angle as a reference indicator, Example 2 showed the best performance (145°), with no visible cracks or peeling after 30 bends. This flexibility originates from the polyurethane skeleton co-constituted with poly(adipate glycol) and siloxane, which possesses excellent elastic recovery capabilities and forms a buffer layer between the coating and the fabric. Simultaneously, the participation of fluorourea ester in crosslinking does not cause excessive hardening of the coating; on the contrary, due to the moderate flexibility of its molecular structure, it lowers the glass transition temperature, helping to maintain the coating's flexibility under low-temperature conditions.

[0046] In summary, the multi-component synergistic design employed in this invention not only improves the three core performance indicators of waterproofing, chlorine resistance, and abrasion resistance, but also achieves a good balance in adhesion and flexibility. Compared to traditional single-structure or physically blended waterproof fabrics, this composite coating system constructs a multi-level stable network and interface reinforcement mechanism based on molecular structure. It can maintain its function for a long time under harsh conditions such as swimming pools, disinfection environments, prolonged dampness, or repeated washing, and has broad engineering practical value and promising prospects for industrial promotion.

Claims

1. A chlorine-resistant, abrasion-resistant, and waterproof fabric, characterized in that, The waterproof fabric comprises the following raw materials in parts by weight: 40-70 parts modified polyurethane elastomer, 20-50 parts fluorourea ester, 2-6 parts aminosilane, 1-3 parts fluorinated surfactant, 1-4 parts crosslinking curing agent, and 0.5-1.5 parts leveling agent.

2. The chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 1, characterized in that, The modified polyurethane elastomer comprises the following raw materials in parts by weight: 20-35 parts of polyadipate glycol, 15-25 parts of isophorone diisocyanate, 5-10 parts of hydroxyl-terminated polydimethylsiloxane, 3-6 parts of polyethylene glycol, 2-6 parts of grafted chitosan, 1-4 parts of dimethylolpropionic acid, 0.5-1.5 parts of triethylamine, 0.1-0.3 parts of dibutyltin dilaurate, and 10-20 parts of deionized water.

3. The chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 1, characterized in that, The fluorourea ester is synthesized from the following raw materials in parts by weight: 5-12 parts of 3,3,3-trifluoroacrylic acid, 4-10 parts of isobutyl isocyanate, 3-8 parts of aminoethanol, 5-12 parts of nonanol, 0.1-0.5 parts of p-toluenesulfonic acid catalyst, and 10-25 parts of ethyl acetate.

4. The chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 1, characterized in that, The fluorinated surfactant is a mixture of potassium perfluorohexyl sulfonate and polyoxyethylene (20) cetyl alcohol in a mass ratio of 1:1; the crosslinking curing agent is a mixture of hexamethylene diisocyanate trimer and 2-hydroxyethyl acrylate in a mass ratio of 3:1; and the leveling agent is a mixture of polyether-modified polydimethylsiloxane and isopropanol in a mass ratio of 4:

1.

5. A chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 1 or 2, characterized in that, The method for preparing the modified polyurethane elastomer includes the following steps: (1) Add polyadipate glycol, polyethylene glycol and hydroxyl-terminated polydimethylsiloxane to a reaction vessel, preheat and dissolve them under stirring to form a mixed polyol component; (2) Cool down to 60-70℃, add isophorone diisocyanate dropwise, and continue the reaction for 2-3 hours to obtain the terminal isocyanate prepolymer; (3) Add dimethylolpropionic acid and continue the reaction for 1-2 hours to introduce a hydrophilic carboxyl group structure, then cool; (4) Triethylamine is added dropwise under stirring to neutralize the carboxyl groups and form a water-soluble structure; (5) Slowly add deionized water to emulsify and disperse, and obtain a uniform waterborne polyurethane emulsion; (6) Add grafted chitosan to the aqueous polyurethane emulsion to complete the end grafting reaction and obtain a modified polyurethane elastomer dispersion.

6. The chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 5, characterized in that, The preheating temperature in step (1) is 80-90℃; the cooling temperature in step (3) is 30-40℃; and the reaction conditions for the end grafting reaction in step (6) are stirring at 40-60℃ for 1-2 hours.

7. A chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 1 or 3, characterized in that, The preparation method of the fluorourea ester includes the following steps: (a) 3,3,3-trifluoroacrylic acid and isobutyl isocyanate were added to a reaction vessel and stirred to generate an isocyanate intermediate; (b) Add aminoethanol to the isocyanate intermediate to generate a reaction solution containing a urea group; (c) Nonanol is added as an esterifying agent to the reaction solution of the intermediate containing the urea group, and fluorourea ester is generated under the catalysis of p-toluenesulfonic acid; (d) After the reaction is complete, ethyl acetate is added for dilution, the mixture is stirred evenly, cooled, filtered, and the solvent is removed under vacuum to obtain the fluorourea ester product.

8. The chlorine-resistant, abrasion-resistant, and waterproof fabric according to claim 7, characterized in that, In step (a), the reaction conditions in the reactor are 50-60°C for 2-3 hours; in step (b), the reaction conditions are 40-50°C for 1-2 hours; and in step (c), the reaction conditions are 60-70°C for 1-2 hours.

9. A method for preparing a chlorine-resistant, abrasion-resistant, and waterproof fabric, wherein the chlorine-resistant, abrasion-resistant, and waterproof fabric is as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1, the modified polyurethane elastomer, fluorourea ester, aminosilane, fluorinated surfactant, crosslinking curing agent and leveling agent are mixed and mixed evenly under stirring conditions to obtain the protective coating liquid. S2, apply the protective coating liquid evenly to the surface of the polyester fabric by dip coating to form a preliminary wet film; S3. The coated fabric is initially dried at 60-80℃ and then heat-cured at 130-150℃ for 10-15 minutes to form a dense and uniform protective coating, resulting in a chlorine-resistant, wear-resistant, and waterproof fabric.

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