A fluorine-containing block copolymer and a method for finishing cotton fabric

Abstract

The application discloses a fluorine-containing block copolymer and a method for finishing cotton fabric. b When the volume ratio of THF to 1,3-bis(trifluoromethyl)benzene is 1:1, the cotton fabric is coated and finished by using a PS-PFPE (4h) solution with a concentration of 80 mg / mL, and a secondary structure morphology with microspheres of different sizes can be obtained, the water contact angle is 156.2±0.5°, and the rolling angle is 9.5±1.5°. The cotton fabric is sprayed and finished, the water contact angle of the finished cotton fabric is 152.7±1.9°, the rolling angle is 5.0±1.8°, and the super-hydrophobic cotton fabric is obtained. The final decomposition temperature of the cotton fabric after the spraying and finishing is increased to 450℃, the heat resistance is improved, the contact angle is 130.7±2.7° after the finished fabric is rubbed by sandpaper for 10 times, and the whiteness and air permeability tests show that the whiteness and air permeability of the cotton fabric before and after the finishing do not change obviously.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fabric finishing, and particularly relates to a fluorine-containing block copolymer and a method for finishing cotton fabric. BACKGROUND

[0002] The performance of super-hydrophobic materials is applied to textiles to make them have excellent performance such as self-cleaning, hydrophobicity, stain resistance and the like to meet various needs of people. The chemical composition and surface microstructure jointly affect the wetting performance of the surface of the material. So far, there are various preparation methods for super-hydrophobic materials, mainly including chemical deposition, electrochemical reaction and electrochemical deposition, etching, electrospinning / jet, sol-gel, template, phase separation and other methods such as wet chemical method, hydrothermal synthesis method, liquid phase deposition method, physical vapor deposition method and the like. Under the background of global ban on non-degradable and permanent chemicals perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonic acid (PFOS), it has important theoretical and practical significance to construct a surface protective coating from naturally degradable perfluoropolyether. Perfluoropolyether (PFPE) generally refers to a polymer with a repeating C-O-C bond in the main chain and hydrogen in the main chain replaced by fluorine, and the average molecular weight range can be from several hundred to tens of thousands. The disadvantage of perfluoropolyether is poor solubility, and it is almost insoluble in all carbon-hydrogen organic solvents except some fluorine-containing small organic molecule solvents. In addition, the poor compatibility and poor compatibility of perfluoropolyether with other materials also greatly limit the more extensive application of perfluoropolyether materials. SUMMARY

[0003] The present application adopts traditional free radical polymerization and atom transfer radical polymerization (ATRP) method to synthesize hydroxyl-terminated polystyrene with different molecular weights, introduces perfluoropolyether chain segment through esterification reaction, and prepares fluorine-containing block copolymer PS- b -PFPE(2h) and PS- b -PFPE(4h) with different polystyrene chain lengths.

[0004] The present application adopts the following technical scheme:

[0005] A fluorine-containing block copolymer has the following chemical structure:

[0006] .

[0007] In the present application, in the structural formula, n and n' represent repeating units; the number average molecular weight of the fluorine-containing block copolymer is 1000-10000, and is preferably 3000-6000.

[0008] The application discloses a preparation method of the fluorine-containing block copolymer, and the fluorine-containing block copolymer is prepared by reacting hydroxyl-terminated polystyrene with perfluoropolyether carboxylic acid. b The number average molecular weight of the perfluoropolyether carboxylic acid is 200-1000, and preferably 300-600.

[0009] The application discloses a cotton fabric finished by the fluorine-containing block copolymer, which comprises the cotton fabric and a fluorine-containing block copolymer coating on the surface of the cotton fabric.

[0010] The application discloses a preparation method of the cotton fabric finished by the fluorine-containing block copolymer, and the fluorine-containing block copolymer coating on the surface of the cotton fabric is prepared by a non-solvent induced phase separation method to obtain the cotton fabric finished by the fluorine-containing block copolymer; or the fluorine-containing block copolymer coating on the surface of the cotton fabric is prepared by an electrostatic spraying method to obtain the cotton fabric finished by the fluorine-containing block copolymer.

[0011] In the application, the styrene is subjected to free radical polymerization in the presence of an azo initiator to prepare the hydroxyl-terminated polystyrene; or the styrene is subjected to atom transfer radical polymerization in the presence of a small-molecule hydroxyl-containing initiator to prepare the hydroxyl-terminated polystyrene.

[0012] In the application, in the non-solvent induced phase separation method, the good solvent is carbon disulfide or tetrahydrofuran; and the non-solvent is selected from small-molecule alcohols and small-molecule benzenes, such as methanol and 1,3-bis(trifluoromethyl)benzene.

[0013] In the application, in the electrostatic spraying method, the solvent is selected from chloroform and / or 1,3-bis(trifluoromethyl)benzene; the concentration of the spinning solution is 20 mg / mL-80 mg / mL; the voltage is 10 kV-14 kV; the receiving distance is 5 cm-20 cm; and the flow rate is 0.6 mL / h-1.0 mL / h.

[0014] The application discloses an application of the fluorine-containing block copolymer in preparing a hydrophobic coating, in particular in preparing a hydrophobic fabric coating.

[0015] The application discloses an application of the cotton fabric finished by the fluorine-containing block copolymer as a hydrophobic material or in preparing a hydrophobic material.

[0016] The present application adopts traditional free radical polymerization, takes 4,4'-azobis(4-cyanopentanol) as an initiator, adjusts the proportion of initiator and monomer, and prepares hydroxyl-terminated polystyrene with different molecular weights. A small-molecule initiator hydroxyethyl isobromobutyrate containing hydroxyl is synthesized by ATRP method using ethylene glycol and 2-bromoisobutyryl bromide; in the PMDETA / CuBr system, the polymerization of styrene is initiated, and hydroxyl-terminated polystyrene PS-OH(2h) and PS-OH(4h) with different chain lengths are prepared by controlling the reaction time. The fluorine-containing block copolymer PS- b -PFPE(2h) and PS- b -PFPE(4h) is prepared by esterification of hydroxyl and perfluoropolyether carboxylate. The intermediates and block copolymers are structurally characterized by FT-IR and 1 H-NMR, and the molecular weight and molecular weight distribution of the fluorine-containing block copolymer are tested.

[0017] Non-solvent induced phase separation method on the surface coating of cotton fabric: the technical effect of the fluorine-containing block copolymer in forming microspheres on the fiber surface when methanol and 1,3-bis(trifluoromethyl)benzene are used as non-solvents respectively is studied. The influence of solvent ratio, concentration, and polystyrene segment molecular weight on the morphology of microspheres is explored. The morphology and surface elements of the microspheres are analyzed by SEM and EDS, the change of the hydrophobic property of the cotton fabric after coating finishing is evaluated by WCA, and the self-cleaning and oil-water separation application performance of the super-hydrophobic cotton fabric after coating are studied and analyzed.

[0018] Electrostatic spraying method for surface coating of cotton fabric: PS- b -PFPE(4h) is prepared into a solution, the influence of different types of solvents, concentration, voltage, receiving distance, and flow rate on the sprayed balls is explored, and the microspheres and microsphere size distribution are characterized by SEM and Image J. The hydrophobicity of the microsphere coating is analyzed by WCA and dynamic contact angle, and the thermal performance, self-cleaning, and oil-water separation performance of the sprayed ball finished cotton fabric are tested. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The route for preparing hydroxyl-terminated HO-PS-OH by traditional free radical polymerization, the infrared spectrum of the initiator ACP and HO-PS-OH: (a) ACP; (b) HO-PS-OH, and the nuclear magnetic spectrum of the initiator ACP and HO-PS-OH: (a) ACP; (b) HO-PS-OH; the solvent is CDCl3.

[0020] Figure 2 The route for synthesizing PS-OH by atom transfer radical polymerization, the infrared spectrum of hydroxyl-terminated polystyrene PS-OH(4h), the 1H-NMR spectra: (a) PS-OH (4h); (b) PS-OH (2h); solvent: CDC13.

[0021] Figure 3 Synthetic route of the fluorine-containing block copolymer, FT-IR spectra of the end-hydroxyl polystyrene and the fluorine-containing block copolymer: (a) PFPE-COOH; (b) PS-OH (2h); (c) PS-OH (4h); (d) PS- b PFPE (2h); (e) PS- b PFPE (4h); and the NMR spectra of the fluorine-containing block copolymer: (a) PS-OH (2h); (b) PS- b PFPE (2h); solvent: CDC13.

[0022] Figure 4 XPS wide scan spectra of PS-OH and PS- b PFPE (2h): (a) PS-OH (2h); (b) PS- b PFPE (2h).

[0023] Figure 5 Influence of different good solvents: (a, al) CS2; (b, bl) THF.

[0024] Figure 6 SEM and particle size distribution of the coating formed on the cotton fabric by different PS segment molecular weights: (a-a2) PS- b PFPE (2h); (b-b2) PS- b PFPE (4h).

[0025] Figure 7 SEM and hydrophobicity of the coating formed by PS- b PFPE (2h) at different volume ratios of THF to 1,3-bis(trifluoromethyl)benzene: (a, al) 2:1; (b, bl) 5:3; (c, cl) 1:1.

[0026] Figure 8 SEM and hydrophobicity of the coating formed by PS- b PFPE (4h) at different volume ratios of THF to 1,3-bis(trifluoromethyl)benzene: (a, al) 2:1; (b, bl) 5:3.

[0027] Figure 9 SEM and hydrophobicity of the coating formed by PS- bSEM images of the coating formed by PFPE (2h) finishing solution and its contact angle with water: (a, a1) raw cotton; (b, b1) 5 mg / mL; (d, d1) 40 mg / mL; (e, e1) 60 mg / mL; (f, f1) 80 mg / mL.

[0028] Figure 10 PS- at different concentrations b SEM images of the PFPE(4h) coating structure and its contact angle with water: (a, a1) raw cotton; (b, b1) 5 mg / mL; (c, c1) 20 mg / mL; (d, d1) 40 mg / mL; (e, e1) 60 mg / mL; (f, f1) 80 mg / mL.

[0029] Figure 11 The effect of different THF to methanol volume ratios on the coating structure: (a, d) 2:1; (b, e) 5:3; (c, f) 1:1; where (ac) PS- b -PFPE(2h); (df)PS- b -PFPE(4h).

[0030] Figure 12 For different concentrations of PS- b SEM images and contact angles of cotton fabrics treated with PFPE (2h) finishing solution: (a, a1) 20 mg / mL; (b, b1) 40 mg / mL; (c, c1) 60 mg / mL.

[0031] Figure 13 For different concentrations of PS- b SEM images and contact angles of cotton fabrics treated with PFPE (4h) finishing solution: (a, a1) 20 mg / mL; (b, b1) 40 mg / mL; (c, c1) 60 mg / mL.

[0032] Figure 14 TGA curves of the fabric before and after finishing.

[0033] Figure 15 To study the oil-water separation, self-cleaning, and anti-fouling properties of finished cotton fabrics: (a) Oil-water separation process diagram; (b) Self-cleaning test; (c) Anti-fouling test; (d) Separation efficiency of 10 oil-water separation cycles.

[0034] Figure 16 The water repellency stability and surface properties of superhydrophobic cotton fabrics: (a) liquid repellency stability; (b) water droplet rolling process diagram; (c) contact angle change after 10 rubs; (d) contact angle change after 10 tape adhesions.

[0035] Figure 17 Microsphere morphology prepared in different solvent types: (a, al) chloroform; (b, bl) chloroform: 1,3-bis(trifluoromethyl)benzene (V:V = 9:1).

[0036] Figure 18 Microsphere morphology and size distribution of electrostatically sprayed microspheres under different concentrations: (a-a2) 20 mg / mL; (b-b2) 40 mg / mL; (c-c2) 60 mg / mL; (d-d2) 80 mg / mL.

[0037] Figure 19 Effect of different voltages on microsphere morphology and size distribution: (a-a2) 10 kV; (b-b2) 12 kV; (c-c2) 14 kV.

[0038] Figure 20 Effect of different receiving distances on microsphere morphology and size distribution: (a-a2) 5 cm; (b-b2) 10 cm; (c-c2) 15 cm; (d-d2) 20 cm.

[0039] Figure 21 Effect of different flow rates on microsphere morphology and size distribution: (a-a2) 0.6 mL / h; (b-b2) 0.8 mL / h; (c-c2) 1.0 mL / h.

[0040] Figure 22 Water contact angle of aluminum foil after spraying microspheres under different concentrations.

[0041] Figure 23 SEM images of cotton fabric and original cotton fabric after electrostatically sprayed microsphere finishing: (a, al) finished cotton fabric; (b, bl) original cotton.

[0042] Figure 24 Picture of the contact angle of the superhydrophobic cotton fabric changing with the sandpaper abrasion period.

[0043] Figure 25 TGA curve of the original cotton and the cotton fabric after coating finishing.

[0044] Figure 26 Oil-water separation and self-cleaning of the cotton fabric after electrostatic spraying finishing: (a) oil-water separation; (b) methylene blue; (c) chalk dust; (d) self-cleaning process diagram.

[0045] Figure 27 SEM image of the cotton fabric without emulsion finishing after electrostatically sprayed microsphere finishing. DETAILED DESCRIPTION

[0046] The present application prepares polystyrene-perfluoropolyether block copolymer (PS- bPFPE (perfluoropolyether carboxylic acid) was applied to the surface of cotton fibers using a solvent-inducible phase separation method and electrostatic spraying. The microstructure, elemental composition, roughness, thermal properties, and wettability of the coating were tested and characterized to develop a superhydrophobic coating finishing method that does not significantly affect the wearability of cotton fabrics. Based on the ATRP method for chemical grafting modification of cotton fabrics and the in-situ generation of rough microstructures, this study investigated further chemical modification of the modified fabrics using PFPE-COOH to obtain superhydrophobic fabrics, potentially expanding the application of PFPE in self-cleaning, oil-water separation, and anti-fouling fabrics. The raw materials used in this invention are all conventional products, and the specific preparation operations and performance testing are conventional techniques. Perfluoropolyether carboxylic acid (PFPE-COOH), number average molecular weight 500; cotton fabric 114 g / m³. 2 Nantong Shengbaolu Textile Co., Ltd., water-friendly.

[0047] 1H NMR (1H NMR) 1 ¹H-NMR analysis was performed using deuterated chloroform (CDCl₃) solution for testing, with tetramethylsilane (TMS) in deuterated chloroform as an internal standard. Small molecule substances underwent 16 scans, while large molecule substances underwent 128 scans. GPC analysis was used to determine the molecular weight and molecular weight distribution of the prepared polymers. Testing was conducted at 35°C with tetrahydrofuran as the mobile phase at a flow rate of 1 mL / min, using polystyrene as a standard.

[0048] The fabric was attached to a glass slide with double-sided tape. A 5 μL water droplet was used as the test droplet. A high-speed camera was used to record the shape of the water droplet when it came into contact with the sample surface. The data were recorded, and the average value and error were calculated. The water contact angle (WCA) was measured. Thermogravimetric analysis was used to analyze the thermal properties of the raw cotton and the finished fabric. The sample was cut into small pieces, and 5 mg was placed in a crucible and then placed in the instrument for testing. The test atmosphere was nitrogen, the test temperature range was 30–600℃, and the heating rate was 10℃ / min.

[0049] Oil-water separation experiment: Heptane stained with oil red and deionized water stained with methylene blue were used as the oil and water agents, respectively, in the test process. Coated cotton fabric was fixed between the upper and lower glass tubes of the oil-water separator as a filter membrane for oil-water separation. 10 mL of oil and 10 mL of water were placed in a graduated cylinder and poured into the glass tubes. The separation effect was observed and the separation efficiency was recorded.

[0050] Self-cleaning test: Methylene blue powder was used as the test contaminant. During the test, the coated cotton fabric was fixed on a glass slide and placed at an angle. Water droplets were then slowly injected into the coated surface using a syringe, and the cleaning phenomenon of the surface contaminant was observed.

[0051] Stain resistance test: the fabric was immersed in a water solution dyed with methylene blue for 1 min, then taken out, and the stain on the surface of the fabric was observed.

[0052] Sandpaper abrasion and tape adhesion tests were used to characterize the mechanical robustness of the superhydrophobic coating.

[0053] (1) Sandpaper abrasion test: the sample fabric of a certain size was placed on a 600-mesh sandpaper, then a 100-g weight was used to press the fabric, and the sample was pulled with tweezers to move it 10 cm in the horizontal direction, and the operation was repeated in the opposite direction, which was recorded as one experiment.

[0054] (2) Tape adhesion test: the fabric was adhered to the tape and pressed with a 100-g weight, then the tape was peeled off, which was recorded as one experiment.

[0055] The air permeability of the cotton fabric before and after coating was tested by a full-automatic air permeability tester. The test parameters were: test pressure: 160 Pa, test area: 20 cm 2 , caliber: 4Φ. Each sample was tested 5 times to take the average value.

[0056] The whiteness of the cotton fabric before and after coating was analyzed by a digital whiteness meter. The sample was placed against 4 times and then placed in the measurement hole, then the instrument was used for testing, and the whiteness value was recorded after the value was stable. Five random points were tested and the average value was taken.

[0057] The tensile breaking strength of the cotton fabric before and after coating was tested by a universal material testing machine. The fabric was cut to 1 cm × 6 cm, the clamping length was 5 cm, and the tensile speed was 20 mm / min.

[0058] Polytetrafluoroethylene tube, 18 S, inner diameter 1.07 mm, outer diameter 1.87 mm; single shaft needle, 18 G, inner diameter 0.84 mm, outer diameter 1.27 mm.

[0059] Example One

[0060] For example, the initiator to monomer ratio was 1:50: 1.0 g (4 mmol) of 4,4'-azobis(4-cyanopentanol) (ACP) was dissolved in 4.5 mL of super-dry tetrahydrofuran (THF) and placed in a constant-pressure dropping funnel. 20.8 g (200 mmol) of styrene was dissolved in 50 mL of THF, and the ACP solution prepared in advance was added dropwise after being heated to 75°C. The addition was completed in 15 minutes, and the reaction was carried out for 5 hours. Then, the reaction solution was rotary evaporated at 50°C to remove the solvent, and the concentrated liquid was precipitated in anhydrous methanol three times. The white solid obtained was dried in a vacuum oven at 50°C to obtain 8.3 g of white solid powder product HO-PS-OH.

[0061] Referring to the above method, the initiator and monomer ratio is adjusted to 1:100 to obtain polymers of different molecular weights.

[0062] Referring to Figure 1 , the route for preparing hydroxyl-terminated HO-PS-OH by traditional free radical polymerization, infrared spectrum of initiator ACP and HO-PS-OH, and nuclear magnetic spectrum. The molecular weight and molecular weight distribution (Mw / Mn) of HO-PS-OH obtained by using different initiator and monomer ratios are tested, as shown in Table 1. As the monomer ratio increases, the molecular weight of the prepared polymer also gradually increases, but the molecular weight distribution is wide.

[0063]

[0064] Example 2

[0065] 246 mg (2 mmol) of cuprous bromide (CuBr) was weighed into a three-necked flask, vacuum sealed, then 2.6 g (25 mmol) of styrene and 7 mL of super-dry THF were added through a needle tube, then vacuumed and purged with nitrogen for 3 times; 211 mg (1 mmol) of hydroxyethyl isobromobutyrate dissolved in 1 mL of super-dry THF was added through a needle tube, vacuumed and purged with nitrogen for 3 times, then 347 mg (2 mmol) of N,N,N',N,'N''-pentamethyldiethylenetriamine (PMDETA) was added, vacuumed and purged with nitrogen for 3 times, then the temperature was raised to 90°C, and the reaction was carried out for 2 h, then the reactor was placed in an ice bath to quench the reaction, then the reaction solution was diluted with THF, and the metal catalyst was removed by passing through a 15 cm neutral alumina column; the concentrated solution obtained by rotary evaporation of the solution at 50°C under reduced pressure was precipitated in ice methanol and centrifuged 3 times, and the white precipitate obtained was dried in a vacuum oven at 50°C for 24 h, and the product obtained was hydroxyl-terminated polystyrene PS-OH (2h).

[0066] Referring to the above method, the reaction time is extended to 4 hours, and hydroxyl-terminated polystyrene PS-OH (4h) is also prepared.

[0067] The ratio of initiator, monomer, cuprous bromide and ligand in this process is 1:25:2:2.

[0068] Referring to Figure 2 , the route for synthesizing PS-OH by atom transfer radical polymerization, infrared spectrum of hydroxyl-terminated polystyrene PS-OH (4h), H-NMR spectrum of PS-OH with different reaction times. 1 In the infrared spectrum of PS-OH (4h), 3022 cm -1 , 3057 cm -1 , 3100 cm-1 The peak at 1600 cm -1 -1 belongs to the stretching vibration of unsaturated C-H on benzene ring, and the peaks between 2000 cm -1 -1 belong to the overtone of benzene ring, indicating that styrene is successfully polymerized. The chemical shift at 6.8 - 7.2 ppm (d') is the peak of meta-proton on benzene ring, and the chemical shift at 6.3 - 6.8 ppm (e') is the peak of ortho-proton on benzene ring of styrene. The ratio of d' to e' is 5:3 by integrating the peaks. The peak at 3.8 ppm is the peak of methylene adjacent to hydroxyl group. Therefore, it can be concluded that PS-OH is successfully prepared. In the case of integrating a' as 1, the integral of 6.3 ppm - 7.2 ppm in (a) and (b) is 106.72 and 65.45, respectively, which indicates that the PS chain segment is growing with time, which is similar to the result shown by GPC.

[0069] The molecular weight and molecular weight distribution of the hydroxyl-terminated polystyrene PS-OH prepared by ATRP method were tested, and the effect of different reaction time on the molecular weight and molecular weight distribution (Mw / Mn) of the hydroxyl-terminated polystyrene is shown in Table 2. It can be seen that the longer the reaction time, the greater the molecular weight of the polymerization product, and the narrower the molecular weight distribution, which indicates that the molecular weight of polystyrene can be controlled by controlling the reaction time.

[0070]

[0071] Example Three

[0072] The fluorine-containing block copolymer PS- b -PFPE was prepared by coupling reaction of PS-OH and perfluoropolyether carboxylic acid under the activation of N,N'-dicyclohexyl carbodiimide (DCC).

[0073] For example, the esterification step of PS-OH (2h): 6.2 g of hydroxyl-terminated PS-OH (2h) and 0.6 g of perfluoropolyether carboxylic acid were taken in a three-necked flask previously equipped with a magnetic stirrer, dissolved with 8 mL of super-dry THF and 4 mL of 1,3-bis(trifluoromethyl)benzene, and then the three-necked flask was placed in an ice bath at 0°C, 24 mg of 4-aminopyridine (DMAP) was added, then 309 mg of DCC was dissolved with 4 mL of super-dry THF and 2 mL of 1,3-bis(trifluoromethyl)benzene, and then added dropwise into the three-necked flask through a constant-pressure dropping funnel under nitrogen protection, the dropping was completed in 15 minutes, and then the reaction was kept for 1 h, and then reacted at 25°C for 24 h. After the reaction was completed, the white precipitate was removed by filtration, the filtrate was rotary evaporated at 55°C to remove the solvent, the obtained concentrated solution was dissolved in THF and precipitated in anhydrous methanol, and the obtained white powder was dried in a vacuum oven at 45°C, to obtain 3.8 g of fluorine-containing block copolymer PS- b-PFPE (2h).

[0074] Referring to the above method, using hydroxystyrene PS-OH (4h), the preparation of fluorine-containing block copolymer PS- b -PFPE (4h).

[0075] See Figure 3 , the synthesis route of fluorine-containing block copolymer, the infrared spectrum of hydroxyl-terminated polystyrene and fluorine-containing block copolymer, the nuclear magnetic spectrum of fluorine-containing block copolymer. Among them, the wide absorption peak between 1099 cm -1 and 1248 cm -1 belongs to the stretching vibration absorption peak of C-F, which shows that the perfluoropolyether carboxylic acid is successfully coupled with the end hydroxyl of polystyrene, and the fluorine-containing block copolymer is prepared; PS- b -PFPE (2h) has a new peak at 4.05 ppm, which belongs to -CH2-OCO-, indicating that the esterification reaction has successfully occurred.

[0076] The end hydroxyl polystyrene before and after esterification and the fluorine-containing block copolymer were tested by XPS, and the wide scan spectrum is shown in Figure 4 . As can be seen from the figure, compared with the unesterified PS-OH (2h), the esterification of PS- b -PFPE (2h) has a strong F 1s signal peak at 689.16 eV, which also proves that the polystyrene-perfluoropolyether block copolymer is synthesized.

[0077] Using traditional free radical polymerization and atom transfer radical polymerization (ATRP), hydroxyl-terminated polystyrene (PS) was synthesized, and active polystyrene with different molecular weights was prepared by controlling the monomer to initiator ratio and reaction time. GPC test shows that the molecular weight distribution of the polymer prepared by ATRP method is 1.09. Different molecular weight polystyrene and perfluoropolyether carboxylic acid (PFPE-COOH) were coupled to obtain fluorine-containing block copolymer PS- b -PFPE (2h) and PS- b -PFPE (4h). The chemical structure of the product was determined by FT-IR and 1 H-NMR, and the molecular weight and molecular weight distribution of the polymer were determined by GPC. The results show that the block polymerization product with controllable structure is successfully prepared.

[0078] Example Four

[0079] A fluorine-containing block copolymer coating was prepared on the surface of cotton fabric by non-solvent induced phase separation method, and a fluorine-containing block copolymer finished cotton fabric was obtained: the polymer PS- bThe PFPE was dissolved in THF or CS2, and placed in an ultrasonic cleaner for 1 h to completely dissolve the fluoropolymer. Then, anhydrous methanol or 1,3-bis(trifluoromethyl)benzene was added, and the solution was placed in an ultrasonic cleaner for 30 min. Then, cotton fabric (2 cm x 2 cm) was immersed in the solution, and taken out after 10 min. The cotton fabric was placed in a desiccator for 24 h to completely evaporate the solvent, to prepare the fluorine-containing block copolymer finished cotton fabric.

[0080] The polymer PS- b The PFPE (2h) was used as raw material, and phase separation was carried out in different good solvents, under the condition that the volume ratio of good solvent to non-solvent (1,3-bis(trifluoromethyl)benzene) was 1:1, and the solution concentration was 40 mg / mL. Figure 5 (a, a1) is the SEM image of the microspheres formed when CS2 is used as the good solvent, and (b, b1) is the SEM image of the microspheres in the coating formed when THF is used as the good solvent. As can be seen from the figure, when CS2 is used as the good solvent, the formed microspheres are less, and there are cracks on the fabric, and the film is not complete. THF is used as the good solvent in the subsequent experiment.

[0081] The block copolymer PS- b -PFPE (2h) and PS- b -PFPE (4h) finishing solution, and the concentration was controlled to be 60 mg / mL. The SEM image and size distribution of the finished fabric are shown in Figure 6 The contact angle of the finished fabric was characterized by WCA, and the contact angle photo is shown in the upper right corner of the figure. As can be seen from the figure, the particle size of the microspheres formed by the polymer with less PS segment is not uniform, and the average particle size of the microspheres formed by the polymer with more PS segment is 1.64 ± 0.32 μm. b The average particle size of the microspheres formed by the PFPE (2h) is 1.20 ± 0.36 μm, and the average particle size of the microspheres formed by the PFPE (4h) is 1.64 ± 0.32 μm. b The average particle size of the microspheres formed by the PFPE (2h) is 1.20 ± 0.36 μm, and the average particle size of the microspheres formed by the PFPE (4h) is 1.64 ± 0.32 μm. b The water contact angle of the coating formed by the PFPE (2h) on the fabric is 149.6 ± 2.1°, and the water contact angle of the coating formed by the PFPE (4h) on the fabric is 154.3 ± 2.2°. b The water contact angle of the coating formed by the PFPE (2h) on the fabric is 149.6 ± 2.1°, and the water contact angle of the coating formed by the PFPE (4h) on the fabric is 154.3 ± 2.2°.

[0082] Figure 7 In order to utilize the fluorine-containing block copolymer PS- b-PFPE (2h) is the raw material, the microstructure coating formed on the surface of cotton fabric by the finishing solution (20 mg / mL) prepared under different THF and 1,3-bis (trifluoromethyl) benzene volume ratio, with the increase of non-solvent 1,3-bis (trifluoromethyl) benzene, the water contact angle of the cotton fabric after finishing coating gradually decreases from 150.0 ± 0.9° to 143.2 ± 0.4°, about 7°. Combined with SEM figure, it can be found that under certain concentration (20 mg / mL), with the increase of 1,3-bis (trifluoromethyl) benzene in the solution, the surface microspheres become less.

[0083] Figure 8 In order to form the microstructure coating on the surface of the fiber by the fluorine-containing block copolymer PS- b -PFPE (4h) is prepared into finishing solution with a concentration of 60 mg / mL, and the block copolymer forms a microstructure coating on the surface of the fiber under different 1,3-bis (trifluoromethyl) benzene content. Combined with Figure 10 , the test results show that when the volume ratio of THF to 1,3-bis (trifluoromethyl) benzene is 1:1, the PS- b The coating formed by PFPE (4h) has the best hydrophobicity, which is 154.3 ± 2.2°.

[0084] When the volume ratio of THF to 1,3-bis (trifluoromethyl) benzene is 2:1, the influence of different concentrations of the solution of fluorine-containing block copolymer PS- b The influence of the hydrophobicity and microsphere structure of the coating formed by the solution of PFPE (2h) on the surface of the fabric is shown in Figure 9 , and the concentrations are 5 mg / mL, 40 mg / mL, 60 mg / mL and 80 mg / mL respectively. From the SEM figure, it can be seen that with the increase of the concentration, the distribution of microspheres on the fiber increases, and the size of the microspheres does not change significantly. With the increase of the concentration of the solution, the contact angle of the fabric after finishing coating increases and then decreases.

[0085] When the volume ratio of THF to 1,3-bis (trifluoromethyl) benzene is 1:1, the PS- b The change of the hydrophobicity and surface structure of the coating of the cotton fabric after the fabric is treated with finishing solution of PFPE (4h) with different concentrations is shown in Figure 10 , and the concentrations are 5 mg / mL, 20 mg / mL, 40 mg / mL, 60 mg / mL and 80 mg / mL respectively. From the figure, it can be seen that with the increase of the concentration of the finishing solution, the microspheres on the fiber increase, and when the concentration is 80 mg / mL, the phenomenon of large balls stacking small balls appears. The appearance of this secondary structure leads to the increase of the contact angle to 156.2 ± 0.5°.

[0086] The microstructure of the coating formed by phase separation of two kinds of fluorinated block copolymers in different volume ratios of THF to methanol was studied, as shown in Figure 11 Fig. 2. When the volume ratio of THF to methanol was 2:1 and 5:3, the fluorinated polymer PS- b -PFPE (2h) formed microspheres on the surface of the fabric, while the fluorinated polymer PS- b -PFPE (4h) formed a microsphere structure when the volume ratio of the two solvents was 1:1. As can be seen from the figure, with the increase of methanol content, the coating formed by PS- b -PFPE (4h) changed from a relatively complete film to a microsphere coating.

[0087] When the volume ratio of THF to methanol was 2:1, the microstructure and hydrophobicity of the coating prepared by the fluorinated polymer PS- b -PFPE (2h) solution with concentrations of 20 mg / mL, 40 mg / mL and 60 mg / mL were as shown in Figure 12 As can be seen from the figure, when the concentration was 40 mg / mL, the coating had cracks, and when the concentration was 60 mg / mL, more and complete microspheres were formed, and the water contact angle of the coating prepared at this time could reach 149.5 ± 4.7°.

[0088] When the volume ratio of THF to methanol was 1:1, the microstructure and hydrophobicity of the coating prepared by the fluorinated polymer PS- b -PFPE (4h) solution with concentrations of 20 mg / mL, 40 mg / mL and 60 mg / mL were as shown in Figure 13 With the increase of the concentration of the polymer solution, the water contact angle of the finished cotton fabric increased from 146.7 ± 1.3° to 150.8 ± 1.6°, and microspheres were formed. When the concentration was 60 mg / mL, it could be observed that there were smaller "papillary" structures on the surface of the microspheres, which was consistent with the formation of secondary structure of the microspheres, which helped to improve the hydrophobicity of the finished cotton fabric, which was consistent with the test results of the contact angle.

[0089] The cotton fabric treated with the fluorinated polymer PS- b -PFPE (4h) solution with a concentration of 60 mg / mL at a volume ratio of THF to 1,3-bis(trifluoromethyl)benzene of 1:1 was subjected to TGA test, and the results were as shown in Figure 14 The initial degradation temperature of the original cotton fabric and the coated cotton fabric had little change, both around 340℃, but the final decomposition temperature of the coated fabric was around 450℃, much higher than the 398℃ of the original cotton fabric. The carbon residue rate of the coated cotton fabric increased from 5.77% to 10.78%, which indicated that the use of fluorinated block copolymers for coating finishing of cotton fabric could effectively improve its heat resistance.

[0090] For the use of PS- at a ratio of 1,3-bis(trifluoromethyl)benzene to tetrahydrofuran (THF) of 1:1 and 60 mg / mL b The properties of cotton fabrics treated with PFPE (4h) solution were analyzed. To test the oil-water separation effect of the coated cotton fabrics, heptane dyed with oil red and aqueous solutions dyed with methylene blue were used as the oil and water agents, respectively; and 10 oil-water separation tests were performed. The specific process is as follows: Figure 15 As shown in (a), the experimental results indicate that after 10 oil-water separation tests, the separation efficiency of the superhydrophobic fabric decreased from 99.4% to 98.3%. Figure 15 (d) Maintain good separation efficiency. For example... Figure 15 As shown in (b), when methylene blue is used as a contaminant, it is washed away by the rolling of water droplets, demonstrating its good self-cleaning properties. A stain resistance test was conducted on the superhydrophobic fabric, as shown... Figure 15 As shown in (c), the fabric did not stain after being immersed in an aqueous solution dyed with methylene blue, demonstrating its good anti-staining properties.

[0091] For the use of PS- at a ratio of 1,3-bis(trifluoromethyl)benzene to tetrahydrofuran (THF) of 1:1 and 60 mg / mL b The hydrophobic properties of cotton fabrics treated with PFPE (4h) solution were analyzed, such as... Figure 16 As shown. Figure 16 (a) shows the liquid repellency stability of the coating. As the standing time increases, the contact angle decreases, but after 30 min, the water contact angle reaches 146.7° ±1.4°, showing good hydrophobic properties. Figure 16 (b) To achieve the dynamic water-repellent process of the finished cotton fabric, the fabric is placed on a glass plate at a low angle (9°). When water droplets fall from above the fabric, they bounce quickly on the fabric under the action of gravity and roll off the surface rapidly. Figure 16 (c) and (d) show the changes in contact angle of the coated fabric after tape application and sandpaper abrasion tests, respectively. With increasing number of tests, the water contact angle of the superhydrophobic cotton fabric gradually decreased, but it still maintained good hydrophobic properties. After 10 sandpaper abrasion tests, the contact angle decreased to 131.8 ± 1.4°; after 10 tape application tests, the contact angle became 134.5 ± 1.8°.

[0092] For the use of PS- at a ratio of 1,3-bis(trifluoromethyl)benzene to tetrahydrofuran (THF) of 1:1 and 60 mg / mL bThe service performance of the cotton fabric after PFPE (4h) solution finishing was analyzed, and the results are shown in Table 3. The whiteness was almost unchanged, and the air permeability decreased slightly. The breaking strength of the cotton fabric after coating finishing increased to 11417.8 cN, which was greatly changed compared with 5800.1 cN of the original cotton fabric. During the coating process, the film and microspheres formed by phase separation covered the surface of the cotton fibers, greatly improving the tensile properties of the cotton fabric.

[0093]

[0094] Polystyrene-perfluoropolyether block copolymer was used as raw material, and non-solvent induced phase separation method was used for coating finishing on the surface of cotton fabric. By controlling the process conditions, super-hydrophobic fabric can be obtained. 1,3-bis(trifluoromethyl) benzene and methanol were used as non-solvents, and tetrahydrofuran and carbon disulfide were used as good solvents. SEM and WCA were used to test the coating morphology and hydrophobicity under different conditions. When the volume ratio of THF to methanol is 1:1, microspheres are formed in the coating. When the concentration of the treatment solution is 60 mg / mL, "papillary" secondary structure grows on the microspheres, and the water contact angle is 150.8 ± 1.6°. When the ratio of 1,3-bis(trifluoromethyl) benzene to tetrahydrofuran (THF) is 1:1, the use of 80 mg / mL PS- b The cotton fabric was coated with PFPE (4h) solution, and a secondary rough structure with composite microspheres of different sizes was obtained. The coating has a water contact angle of 156.2 ± 0.5° and a rolling angle of 9.5 ± 1.5°. AFM tests show that the surface roughness of the coated fabric increases, and EDS tests show that the F element is uniformly distributed on the fiber surface, with a F element content of 1.99%. The rough structure produced by fluorine-containing polymers under non-solvent induced phase separation and the combination of low surface energy substances endow the cotton fabric with super-hydrophobic properties. The abrasion resistance, self-cleaning, and oil-water separation properties of the coated fabric were tested. TGA tests on the finished cotton fabric show that coating finishing improves the heat resistance of the fabric, and the final decomposition temperature of the fabric increases from 398°C to about 450°C.

[0095] Example Five

[0096] The principle of electrostatic spraying is to establish an electrostatic field between a nozzle with high-voltage static electricity and a receiver. Under the action of high-voltage electricity, the droplets become spindles, and the liquid stream produced at the top of the cone can be split into small droplets. Under the action of the electrostatic field, the droplets move directionally and are received by the receiver. There are many factors that affect electrostatic spraying, such as voltage, solvent properties, polymer properties, receiving distance, environmental conditions, etc.

[0097] Fluorine-containing block copolymer PS- b-PFPE (4h) was dissolved in solvent, stirred at room temperature for 4 h to prepare a transparent and uniform solution, and then ultrasonic for 2 h to remove bubbles to obtain an electrospinning solution. The electrospinning device was used to perform electrospinning experiment on the prepared solution, and the electrospinning time was 1.5 h, the temperature was 20℃ ± 2℃, and the humidity was 50% ± 5%. The microsphere coating was prepared on the aluminum foil paper.

[0098] Under the conditions of electrospinning solution concentration of 80 mg / mL, flow rate of 0.8 mL / h, voltage of 10 kV, and receiving distance of 10 cm, the microsphere coating was prepared by different solvents, as shown in Figure 17 As shown in (a, a1), the microsphere morphology formed when chloroform was used as the solvent. It can be observed that compared with the chloroform and 1,3-bis(trifluoromethyl)benzene (V:V=9:1) system (b, b1), the morphology tends to be spherical, and the formed ball is more deflated under the mixed system, similar to the airbag structure. The EDS was used to analyze the elements on the surface of the microsphere prepared by chloroform as the solvent, and the proportion of F element was 2.77%.

[0099] Under the conditions of chloroform as the solvent, working voltage of 10 kV, receiving distance of 10 cm, and flow rate of 0.8 mL / h, the microsphere structure was prepared by different electrospinning solution concentrations. As shown in Figure 18 As shown in the particle size distribution graph, the abscissa is the diameter, the unit is microns (μm), and the ordinate is the number of times of each range size in 150 tests. It can be seen from the graph that as the concentration increases, the particle size distribution of the microsphere becomes narrower, and at 80 mg / mL, there is a relatively narrow particle size distribution, and the average particle size is 4.66 ± 0.72 μm.

[0100] Under the conditions of fixing other process parameters (concentration of 80 mg / mL, flow rate of 0.8 mL / h, and receiving distance of 10 cm), the microsphere structure was prepared under different voltages. Figure 19 As shown in the scanning electron microscope graph and size distribution graph of the microspheres prepared under different voltages, as the voltage increases from 10 kV to 14 kV, the size distribution of the microspheres becomes wider, and the average size first increases and then decreases, and at 10 kV, it has the narrowest particle size distribution.

[0101] Under the conditions of fixing other process parameters, different receiving distances were used to prepare electrospun balls, and the concentration of the finishing liquid was 80 mg / mL, the voltage was 10 kV, and the flow rate was 0.8 mL / h. Figure 20(a-d) are the scanning electron microscope images and size distribution pictures of the microspheres received at a distance of 5 cm, 10 cm, 15 cm, 20 cm, respectively. Between 5 cm and 10 cm, the size of the microspheres increases with the increase of the receiving distance. Between 10 cm and 20 cm, the size of the microspheres changes little. However, the size distribution of the microspheres becomes wider when the receiving distance is 15 cm and 20 cm.

[0102] With other parameters fixed (the concentration of the finishing solution is 80 mg / mL, the voltage is 12 kV, and the receiving distance is 10 cm), the flow rate is changed from 0.6 mL / h to 1.0 mL / h, and the change of the size of the electrostatically sprayed microspheres is shown in Figure 21 As can be seen from the figure, under the condition of a voltage of 12 kV, when the flow rate is increased from 0.6 mL / h to 0.8 mL / h, the average size of the microspheres increases from 4.28 ± 0.72 μm to 5.82 ± 0.96 μm, and the size distribution of the microspheres becomes wider with the increase of the flow rate.

[0103] Under the condition of chloroform as the solvent, the working voltage is 10 kV, the receiving distance is 10 cm, and the flow rate is 0.8 mL / h, the hydrophobic performance of the aluminum foil paper after spraying microspheres at different concentrations is tested, and the results are shown in Figure 22 As the concentration increases, the water contact angle of the aluminum foil increases. The water contact angle of the uncoated aluminum foil is 42.9 ± 0.6°, and as the concentration of the sprayed solution increases from 20 mg / mL to 80 mg / mL, the static contact angle of the aluminum foil paper increases from 150.7 ± 0.6° to 159.3 ± 1.0°, and the rolling angle at this time is 1.8 ± 0.3°.

[0104] Example Six

[0105] Preparation of the acrylate emulsion:

[0106] (1) Preliminary preparation: 78.0 g of deionized water, 2.0 g of OP-10, 1.0 g of sodium dodecyl sulfate, 83.0 g of vinyl acetate, 8.0 g of butyl acrylate, 5.0 g of methyl methacrylate, 2.8 g of acrylic acid, and 1.2 g of N-methylol acrylamide were added to a 500 mL beaker as mixed monomers. The mixture was pre-emulsified under high-speed shearing stirring for 10 min with a high-speed emulsifier to obtain a pre-emulsion, which was prepared. 0.5 g of sodium persulfate was added to 17.0 g of deionized water to obtain a sodium persulfate initiator solution, which was prepared. 0.2 g of sodium bicarbonate was added to 4.0 g of deionized water to obtain a sodium bicarbonate buffer solution, which was prepared.

[0107] (2) Emulsion polymerization: 57.0 g of deionized water, 28.0 g of pre-emulsion and 1.0 g of buffer solution were added into a three-necked flask with nitrogen protection. After the temperature rose to 75°C, 3.0 g of initiator solution was slowly added through a constant pressure dropping funnel. After the system temperature was stable, the remaining buffer solution, initiator solution and pre-emulsion were added drop by drop. The dropping speed was controlled to keep the system temperature stable at about 75°C. After the dropping was completed, the reaction was maintained for 1 h, then the product was cooled and discharged to obtain the vinyl acetate-acrylate emulsion.

[0108] The prepared vinyl acetate-acrylate emulsion was diluted to 3 g / L. Then cotton fabric (6 cm x 15 cm in size) was immersed in the diluted emulsion according to a bath ratio of 1:200, and was subjected to two immersions and two rollings with a pick-up rate of 65%. The fabric without emulsion treatment was directly sprayed as a comparison, see Comparative Example 2.

[0109] The fluorine-containing block copolymer PS- b -PFPE (4h) was dissolved in solvent chloroform, stirred at room temperature for 4 h to prepare a transparent and uniform solution, and then ultrasonic treatment was performed for 2 h to remove air bubbles to obtain an electrospinning solution. The cotton fabric after padding was fixed on the receiving cylinder of the electrospinning machine with double-sided tape, the fixing rotation rate was 50 mm / s, the finishing liquid concentration was 80 mg / mL; the electrospinning machine voltage was 10 kV, the flow rate was 0.8 mL / h, the receiving distance was 10 cm, the electrospinning time was 1.5 h, the temperature was 20°C ± 2°C, and the humidity was 50% ± 5%. After the electrospinning finishing was completed, the fabric was placed in a 50°C oven for drying and crosslinking. The cotton fabric after electrospinning finishing was subjected to XPS analysis, and the test showed that the surface element content of the raw cotton fabric was F 1s 7.93%, C 1s 61.8%, O 1s 30.18%, F 1s The appearance of F

[0110] Figure 23 The scanning electron micrographs of the cotton fabric before and after microsphere spraying finishing and the picture of the water static contact angle of the fabric after electrospinning finishing are shown in FIGS. 1 and 2. As can be seen from the figures, the surface of the raw cotton fiber is relatively flat and smooth with a few grooves and textures, and there is a certain gap between the fibers. After electrospinning finishing, the microspheres on the cotton fabric and the wrinkles on the microspheres give the cotton fabric a rough structure; under the combined action of the low surface energy material, the hydrophobic property of the finished fabric surface is greatly improved, the water contact angle is 152.7 ± 1.9°, and the rolling angle is 5.0 ± 1.8°.

[0111] The super-hydrophobic cotton fabric after electrospinning finishing was subjected to friction test, as shown in Table 1. Figure 24As shown in the figure, after 10 sandpaper rubbing treatments, the water contact angle of the fabric decreased from the initial 152.7 ± 1.9° to 130.7 ± 2.7°. This indicates that the fabric still retains hydrophobic properties after the rubbing treatment. Furthermore, the figure shows that in the 10 rubbing experiments, the rate of decrease in the contact angle slows down with the increase of the number of rubbing cycles.

[0112] Thermal analysis was performed on the cotton fabric treated with electrostatic spraying, such as... Figure 25 As shown, after PS- b -PFPE(4h) treatment increases the final decomposition temperature of cotton fabric to about 480℃, increases the residual carbon rate from 5.77% to 9.86%, and improves heat resistance.

[0113] The oil-water separation and self-cleaning properties of cotton fabrics treated with microsphere coatings were tested, and the results are as follows: Figure 26 As shown. Among them. Figure 26 (a) is a diagram of the oil-water separation process of cotton fabric after microsphere treatment. A mixture of 10 mL of methylene blue-dyed deionized water and 10 mL of oil red-dyed n-heptane was injected into a graduated cylinder. Under the action of gravity, the oil droplets were quickly absorbed by the cotton fabric and flowed into the collector at the bottom, while the water could not penetrate, thus achieving oil-water separation. Figure 26 (b) and (c) show the self-cleaning process of the fabric with methylene blue powder and chalk dust as contaminants, respectively. During the process of adding water to the fabric surface with a syringe, the contaminants distributed on the sample are carried away from the sample surface by the rolling water droplets. These results indicate that the cotton fabric treated with electrostatic spraying has good oil-water separation and self-cleaning properties.

[0114] The whiteness and air permeability of the cotton fabric treated with electrostatic spraying were tested. The results are shown in Table 4. Electrostatic spraying treatment had almost no effect on the whiteness of the fabric, and the air permeability of the cotton fabric before and after treatment did not change much.

[0115]

[0116] With PS- b Using PFPE (4h) as raw material, electrostatic spraying technology was employed to treat cotton fabrics with microspheres. Preferably, under the conditions of a finishing solution concentration of 80 mg / mL, a voltage of 10 kV, a receiving distance of 10 cm, and a flow rate of 0.8 mL / h, a microsphere coating with uniform particle size could be obtained. WCA test results showed that the water contact angle of the microsphere coating on aluminum foil was 159.3 ± 1.0°, and the roll-off angle was 1.8 ± 0.3°. Applying the optimized process to cotton fabric treatment, a superhydrophobic cotton fabric was obtained after microsphere coating treatment, with a water contact angle of 152.7 ± 1.9° and a roll-off angle of 5.0 ± 1.8°. Test results indicate that this superhydrophobic cotton fabric exhibits good oil-water separation and self-cleaning properties.

[0117] Comparative Example One

[0118] PFPE cannot directly arrange raw cotton, and the method of preparing cotton-Br first and then modifying PFPE is adopted. Referring to CN2023105627032, the water contact angle of cotton-PFPE is less than 140°, and the full-fluoropolyether chain is coupled on the surface of the fiber to modify the hydrophobic effect of the fabric, which is not ideal, and far from achieving the super-hydrophobic level. Even if the method of chemical grafting PS and then modifying PFPE is adopted, the super-hydrophobic effect cannot be achieved, see the prior application comparative example two.

[0119] Comparative Example Two

[0120] When the acetone-propylene emulsion padding is not used, the morphology and water contact angle of the electrostatic spray microspheres under the same conditions are as shown in Figure 27 The water contact angle on the fabric treated by the emulsion is 132.7 ± 2.1°, and the water contact angle on the fabric treated by the emulsion is 152.7 ± 1.9°.

[0121] The present application prepares polystyrene-perfluoropolyether block copolymer (PS- b -PFPE), and forms a coating on the surface of cotton fabric fibers by using non-solvent induced phase separation method and electrostatic spraying method, which has obvious super-hydrophobic performance and mechanical stability, and also has excellent oil-water separation and self-cleaning performance, and can maintain the whiteness and air permeability of the fabric, and has good application prospect.

Claims

1. A cotton fabric finished with a fluorine-containing block copolymer, comprising a cotton fabric and a fluorine-containing block copolymer coating layer on the surface of the cotton fabric, wherein the fluorine-containing block copolymer coating layer is prepared on the surface of the cotton fabric by electrostatic spraying to obtain the cotton fabric finished with the fluorine-containing block copolymer; characterized in that, The chemical structural formula of the fluorine-containing block copolymer is as follows: ​ ； The number average molecular weight of the fluorine-containing block copolymer is 1000-10000; In the electrostatic spraying method, the solvent is selected from chloroform and / or 1,3-bis(trifluoromethyl)benzene; the concentration of the spinning solution is 20 mg / mL-80 mg / mL.

2. The cotton fabric finished with the fluorine-containing block copolymer according to claim 1, characterized by, The hydroxyl-terminated polystyrene is reacted with a perfluoropolyether carboxylic acid to obtain the fluorine-containing block copolymer.

3. The cotton fabric finished with the fluorine-containing block copolymer according to claim 2, characterized by, The hydroxyl-terminated polystyrene is prepared by free radical polymerization of styrene in the presence of an azo initiator, or by atom transfer radical polymerization of styrene in the presence of a small-molecule hydroxyl-containing initiator.

4. A process for finishing cotton fabric with the fluorine-containing block copolymer of claim 1, characterized in that, The fluorine-containing block copolymer coating is prepared on the surface of the cotton fabric by the electrostatic spraying method to obtain the fluorine-containing block copolymer finished cotton fabric; in the electrostatic spraying method, the solvent is selected from chloroform and / or 1,3-bis(trifluoromethyl)benzene; the concentration of the spinning solution is 20 mg / mL-80 mg / mL.

5. The fluorine-containing block copolymer finished cotton fabric of claim 1 is used as a hydrophobic material, or is used in the preparation of a hydrophobic material.

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