Patent Application
20240344264
The present invention belongs to the hydrophobic technology, and specifically relates to a fluorine-free carbon chain hydrophobic fabric and its preparation method and application.
In recent years, constructing polymer structures connected by covalent bonds through covalent on-surface polymerization has become a hot research topic in surface molecular science. Thanks to the rapid development of scanning probe microscopy technology, researchers have gradually begun to explore the process of covalent on-surface polymerization at the atomic level. The carbene polymerization of α-diazo carbonyl compounds is an efficient polymerization method that has attracted great attention from scholars in recent years. However, its reaction mechanism and the application of carbene polymerization still require continuous research and exploration by researchers. The existing technology disclosed a waterproof fabric material and its preparation method, and it consists of a substrate and a water repellent fabric. The water repellent fabric consists of a fabric and a fluorine-containing polymer covalently grafted onto the fabric surface through carbene polymerization. The fluorine-containing polymer with a single carbon repeating unit is covalently grafted onto the fabric surface through carbene polymerization to produce a hydrophobic modified fabric. In the water repellent treatment of fabrics, long-chain perfluoroalkyl (C≥8) polymer is one of the most ideal low surface energy polymeric materials, but this type of compound has high stability, and it makes itself difficult to degrade through conventional degradation methods such as photodegradation, chemical degradation, and microbial degradation on the contrary, which contradicts the growing demand for green and pollution-free environment in the society.
The present invention adopts low surface energy fluorine-free long carbon chain monomers for chemical grafting on the fiber surface of fabrics, which can effectively solve the problem of environmental pollution, and generates a roughened surface morphology on the fiber surface after grafting in situ, which can be repellent to water synergistically with the chemical protection of the low-surface-energy polymers on the fiber surface. The present invention first synthesized 1,2-bis (p-Toluenesulfonyl) hydrazine from p-Toluenesulfonyl hydrazine and p-Toluenesulfonyl chloride as raw materials, with pyridine as a catalyst. Then, C—Br bonds were introduced on the fiber surface, and the latter was transformed into diazo groups by 1,2-bis (p-Toluenesulfonyl) hydrazine treatment under the catalysis of DBU. Through EDS analysis, it was found that grafting sites were successfully constructed on the fiber surface. Hexanol was used as a raw material for the substitution reaction with bromoacetyl bromide to produce hexyl bromoacetate intermediate, which was then synthesized with 1,2-bis (p-Toluenesulfonyl) hydrazine under the catalysis of DBU to produce hexyl diazoacetate, and the product structure was characterized by FT-IR and NMR. Then, butanol, octanol, dodecanol, tetradecanol, and octadecanol were selected as raw materials to react with bromoacetyl bromide to prepare alkyl bromoacetate. Then, it reacted with 1,2-bis (p-Toluenesulfonyl) hydrazine under the catalysis of DBU to produce diazoacetate esters with different carbon chain lengths (butyl diazoacetate, capryl diazoacetate, dodexyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate). The target product was successfully synthesized through FT-IR and NMR, and cotton fibers were graft modified with different diazoacetate monomers, and the polymer was successful grafted through EDS, ATR, and XPS; Through SEM, AFM, and ImageJ analysis of the surface morphology of the fabric, it was found that the fiber surface after grafting with butyl diazoacetate exhibited a “roughened” morphology, with an average size of 351.57±87.13 nm, and the spatial structure of the fiber surface collapsed after grafting with capryl diazoacetate, and the fabric surface became a membrane structure after grafting with dodexyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate and the surface RMS (roughness) also decreased from 48.7 nm to 12.1 nm. The water contact angles of the fabrics grafted with butyl diazoacetate, capryl diazoacetate, dodexyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate were tested to be 116.2±0.8°, 124.0±2.1°, 129.3±1.1°, 130.1±0.9°, 131.2±1.3°, and 133.4±1.8°, respectively. After the pendant group carbon chains of the grafted polymer were ≥8, continuing to extend the pendant group carbon chains could not improve the hydrophobic property of the grafted fabrics. Using diazoacetate as a monomer and using different fiber graft modification processes, the different structures exhibited on the fiber surfaces; The comprehensive properties of the treated fabrics, including thermal stability, permeability, and breaking strength, were tested and the heat resistance and breaking strength of the treated fabric decreased, while the permeability was good.
The present invention adopts the following technical scheme: a fluorine-free carbon chain hydrophobic fabric, and the diazotized fabric reacts with diazoacetate monomer to obtain the fluorine-free carbon chain hydrophobic fabric; and the diazoacetate monomer is butyl diazoacetate, hexyl diazoacetate, capryl diazoacetate, dodexyl diazoacetate, myristyl diazoacetate, or octadexyl diazoacetate.
The present invention discloses the application of diazoacetate monomer in the preparation of fluorine-free carbon chain hydrophobic fabric; and the diazoacetate monomer is butyl diazoacetate, hexyl diazoacetate, capryl diazoacetate, dodexyl diazoacetate, myristyl diazoacetate, or octadexyl diazoacetate.
The present invention disclosed the application of the above-mentioned fluorine-free carbon chain hydrophobic fabrics in the preparation of hydrophobic flexible materials; the fabrics of the present invention are natural fiber fabrics, chemical fiber fabrics, or a blend thereof, such as cotton fabrics.
In the present invention, the fabric was sequentially soaked in alkaline solution and acid solution to obtain a pre-treated fabric; then, the pre-treated fabric was reacted with bromoacetyl bromide to obtain the treated fabric; the pre-treated was reacted with 1,2-bis (p-Toluenesulfonyl) hydrazine to obtain the diazotized fabric; preferably, the alkaline solution was sodium hydroxide aqueous solution, and the acid solution was glacial acetic acid aqueous solution; when the pre-treatment fabric was reacted with bromoacetyl bromide, sodium bicarbonate was used as an acid binding agent, and the reaction was carried out at −5° C. to 25° C. for 1-24 hours; the reaction between the pre-treated fabric and 1,2-bis (p- Toluenesulfonyl) hydrazine was carried out in the presence of DBU, and the reaction was carried out at 0-25° C. for 1-24 hours.
In the present invention, the molar ratio of diazoacetate monomer to diazotized cotton fabric surface hydroxyl was 5-40:1, preferably 10-30:1, and further preferably 20-30:1. The reaction of diazotized fabric and diazoacetate monomer was carried out under nitrogen gas, in a solvent, in the presence of palladium catalyst and reducing agent. Preferably, the solvent was tetrahydrofuran, the palladium catalyst was (π-allylPdCl)2, and the reducing agent was NaBPh4; The reaction process between diazotized fabric and diazoacetate monomer was at 0° C., 5° C., and 15° C. for 1 hour each, and then at 30° C. for 12-36 hours.
At present, the main method of graft polymerization on the surface of fabrics is olefin polymerization (C2 polymerization), but it is difficult to undergo polymerization when the C═C double bond of olefins contains multiple polar functional groups. The present invention adopts the carbene polymerization of α-carbonyl diazo compounds to solve this problem, in which the main polymer chain is composed of a carbon atom as the structural unit, and the pendant groups of the main chain of polymer are more intensive. Fluoroalkyl based polymers have excellent chemical liquid repellency and are the most common fabric water repellent treatment agents. However, they have environmental pollution issues and have been banned. Therefore, the present invention uses low surface energy fluorine-free long carbon chain monomers instead of long carbon chain perfluoroalkyl monomers for graft polymerization on the fiber surface to obtain the superhydrophobic fabric on the premise of effectively solving environmental pollution. Firstly, a reactive base is constructed on the surface of fabric fibers, and then long carbon chain monomers are graft polymerized on the fiber surface to explore the relationship between different processes and the surface morphology of modified fibers. It also explores the relationship between the surface structure of graft modified fibers and properties after polymerization of carbene monomers with different carbon chain lengths, especially the physical structure patterns of the surface formed by polymerization of monomers with different carbon chain lengths, and the resulting surface characteristics.
Cotton fabric (commercially available, untreated), and pyridine and 1-butanol were purchased from J&K Chemical Ltd., and p-Toluenesulfonyl hydrazine, p-toluenesulfonyl chloride, sodium tetraphenylborate, allylpalladium (II) chloride dimer were purchased from Shanghai Aladdin Bio-Chem Technology Co., LTD, and sodium chloride, sodium bicarbonate, dichloromethane (high-purity), anhydrous ethanol, and DBU were purchased from Sinopharm Chemical Reagent Co., Ltd., anhydrous sodium sulfate, tetrahydrofuran (high-purity), anhydrous ether, and anhydrous methanol were purchased from Chinasun Specialty Products Co., Ltd., and n-butanol, 1-octanol, dodecanol, tetradecanol, and octadecanol were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Unless otherwise specified, all reagents were of analytical grade.
The molecular formula of cellulose is (C6H12O12)n, and when M g of alkalized cotton fabric is taken, the amount of hydroxyl groups on its surface is calculated as: M/162×103 mmol.
KBr (or a mixture of KBr and solid samples) was ground into powder in a mortar and baked under a heating lamp until dry. An appropriate amount of KBr powder was weighed and pressed for 10 seconds under a pressure of 1 ton. The liquid sample was dripped on the KBr tablet through a capillary tube and placed inside an infrared spectrometer for testing. Analysis results obtained through nuclear magnetic hydrogen spectrum (1H-NMR). A small amount of the sample to be tested was taken and dissolved in chloroform-d (CDCl3) or dimethyl sulfoxide-d6 (DMSO), and tested using an INOVA-400 nuclear magnetic resonance spectrometer with tetramethylsilane (TMS) as the internal standard.
The fabric to be tested was placed in an oven and dried at low temperature. After removal, it was placed on the test bench of the Nicolet iS5 infrared spectrometer. The test hole was covered and pressed tightly. The instrument resolution was set to 4 cm−1, the scanning range was 4000-500 cm−1, and it was scanned 12 times (SEM). A square fabric with a side length of 5 mm was taken and stuck onto the electron microscope table with conductive adhesive. The vacuum pumping and metal spraying were carried out six times, and S4800 field emission scanning electron microscope was used to test the microstructure of the fiber surface.
The fabric to be tested was fixed flat on a microscope slide and placed on the sample table of OCA40 droplet wettability tester with the camera aligned. The deionized water was used as the test droplet, with a volume of 3 μL. The angle was calculated through instrument software, and each sample was tested 5 times, taking the average value and calculating the error.
The fiber surface morphology and three-dimensional structure of the fabric to be tested were observed using a Nanoscope V-type atomic force microscope. A sample with a diameter of approximately 1 cm was fixed flat on a matching iron plate, and the surface roughness was calculated using an instrument. The scanning range was set to 2 μm×2 μm.
The fabric to be tested was cut into powder form, and about 5 mg of the sample was taken and placed in a crucible. Then it was placed in a Diamond 5700 thermogravimetric analyzer, and the test gas was set to air, with a temperature range of 30° C.-600° C. and a heating rate of 20° C./min. Determination of fabric permeability. According to the standard GB/T 5453-1997 “Determination of Permeability of Fabrics to Air”, a test sample with an area of 20 cm2 was placed on the test table of a fully automatic permeability meter, the test pressure difference was set to 100 pa, and the average of five tests for each sample was taken.
The fabric to be tested was clamped on the GP-6114S-300K universal material testing machine, the force sensing range was set to 1000N, the stretching speed was set to 100 mm/min, the clamping length was 50 mm, the fabric width was 45 mm, and 5 tests were made for each sample in the warp and weft directions and the average value was taken. During the X-ray photoelectron spectroscopy (XPS) analysis, Al-Kα (hν=1486.6 eV) monochromatic X-ray source was used to analyze the surface elements of the fabric before and after grafting, with a pressure setting of 4.0×10−9 Pa and an incidence angle of 90°.
Synthesis example: Synthesis of 1, 2-bis (p-Toluenesulfonyl) hydrazine (TsNHNHTs) and the synthesis route is shown in the following:
Under the nitrogen protection, 18.64 g (100.00 mmol) of p-Toluenesulfonyl hydrazine and 28.60 g (150.00 mmol) of p-toluenesulfochloride were added to a 1000 ml three-necked flask. 120 mL of dichloromethane (dehydrated) was used as the solvent, and 11.96 g (150.00 mmol) of pyridine was dropped dropwise under nitrogen gas protection in 10 minutes. After stirring at room temperature for 3 hours, 300 mL of anhydrous ether was added to make the solution turbid. After cooling to 0° C., 200 mL of deionized water was added and then it was filtered to obtain a light-yellow floccule. Then it continued to be filtered with 150 mL of anhydrous ether to obtain a white solid, which was placed in an oven and dried at 30° C. The white solid after drying was dissolved in 400 mL of methanol and heated to boiling until the solid was completely dissolved, then it was cooled to room temperature for crystallization. The 24 g white crystallized product was finally obtained with a yield of: 70.0%. Product FT-IR (KBr, cm−1): 3229, 3205 (N—H); 3065, 2942 (Ph-H); 1512 (—CH3); 1607, (C—C); 1345, 1210, 1188 (Ph-SO2—N); 1043 (S—N). 1H NMR (400 MHZ, DMSO): 1.47 (—CH3); 6.32 (Ph-H); 6.93 (Ph-H); 8.69 (N—H) ppm.
Synthesis of hexyl diazoacetate (HDA) and the synthesis route is shown in the following:
Hexanol (2.00 g, 20 mmol) was added to a three-necked flask containing 100 mL of dehydrated dichloromethane. Then 5.04 g (60 mmol) of sodium bicarbonate was added as an acid-binding agent. After that, the temperature was lowered to −5° C. in a nitrogen environment. Then, the bromoacetyl bromide (3.5 mL, 40.4 mmol) pre-dissolved in the 5 ml dehydrated dichloromethane was added into the three-necked flask through a syringe and the temperature was raised to the room temperature for 24-hour stirring. Then, 60 mL deionized water was added and the solution was transferred to a 1000 ml separating funnel. It was extracted with dichloromethane three times and dried with anhydrous sodium sulfate. After filtration and rotary evaporation, purification was carried out using silica gel column chromatography. The eluent ratio was dichloromethane: n-hexane=3:1 (v/v). After rotary distillation, a light-yellow oily product (monomer) of 2.72 g was obtained, with a yield of: 61%. Product FT-IR (KBr, cm−1): 3134, 2659 (C—H); 1728 (C═O); 1291 (CO—O); 1113 (O—C—C). 1H NMR (400 MHZ, CDCl3): 3.78 (Br—CH2) ppm.
The hexyl bromoacetate (2.00 g, 6.51 mmol) obtained from the previous step and N, N′-dimethylbenzene sulfonyl hydrazide (4.44 g, 13 mmol) was dissolved in 60 mL of dehydrated tetrahydrofuran, and added into a 50 ml three-necked flask, and cooled to −5° C. in an ice bath. The DBU (6.70 mL, 44.8 mmol) diluted in 10 ml of dehydrated tetrahydrofuran was added into the reaction bath through a 20 ml syringe, then heated up to 10° C. for 2-hour reaction, transferred to a reciprocating shaker bath, and slowly heated up to 25° C. for 24-hour reaction. 20 ml of deionized water was added to stop the reaction, extracted three times with dichloromethane, and dried with anhydrous sodium sulfate. After filtration and rotary evaporation, the product was purified by silica gel chromatography. A mixed solvent of ethyl acetate/dichloromethane=1:5 (v/v) was selected as the eluent, and the main elution band was evaporated to obtain 0.68 g of dark brown oily product with a yield of 41%. Product FT-IR (KBr, cm−1): 3144, 3012 (C—H); 2121 (C═N2); 1644 (C—O); 1391 (—CH2); 1271 (CO—O); 1113 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.68 (H—C═N2) ppm.
5.04 g (60 mmol) of sodium bicarbonate and 1.48 g (20 mmol) of n-butanol were added to a three-necked flask containing 100 mL of dehydrated dichloromethane, respectively. 3.5 mL (40.4 mmol) of bromoacetyl bromide was added at −5° C. for 1-hour reaction, and heated up to 5° C., 15° C., and 25° C. for 1-hour reaction each, then heated up to 30° C. for 24-hour oscillatory reaction. 50 ml of deionized water was added to stop the reaction, and it was extracted three times with dichloromethane, dried with anhydrous sodium sulfate, filtered and evaporated, and purified through silica gel column chromatography. The eluent was a mixed solvent (dichloromethane: n-hexane=4:1, v/v). After purification, a light-yellow oily product of 2.72 g was obtained with a yield of 71.0%. Product FT-IR (KBr, cm−1): 3133, 2659 (C—H); 1728 (C═O); 1288 (CO—O); 1110 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.09 (Br—CH2) ppm.
2.72 g (14.2 mmol) of butyl bromoacetate from the previous step was dissolved in 100 ml of dehydrated tetrahydrofuran, 8.85 g (23 mmol) of N, N′-toluenesulfonyl hydrazine was added, and it was dissolved in a three-necked flask and cooled down to −5° C. 6.70 mL DBU was diluted in 10 ml of dehydrated tetrahydrofuran and added dropwise into a three-necked flask with an injector under nitrogen conditions. The reaction solution in the flask quickly turned yellow, accompanied by the generation of bubbles. After it was heated to 25° C. and reacted for 24 hours, 30 ml of deionized water was added for dilution. It was extracted three times with dichloromethane, and the anhydrous sodium sulfate was added for drying, and after filtration and rotary evaporation, it was purified with silica gel chromatography (ethyl acetate:dichloromethane=1:5, v/v) to obtain 0.82 g of butyl bromoacetate with a yield of 49.1%. Product FT-IR (KBr, cm−1): 3130, 2959 (C—H); 2111 (C═N2); 1641 (C═O); 1400 (—CH2); 1271 (CO—O); 1110 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.73 (H—C═N2) ppm.
Synthesis route of capryl diazoacetate, dodexyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate is shown in the following:
(1) Synthesis of Octyl Bromoacetate, Dodecyl Bromoacetate, Tetradecyl Bromoacetate, and Octadecyl Bromoacetate: 2.6 g (20 mmol) of octanol, 3.72 g (20.0 mmol) of dodecanol, 4.28 g (20.0 mmol) of tetradecanol, and 5.42 g (20.0 mmol) of octadecanol were added into a three-necked flask containing 100 mL of dehydrated dichloromethane, respectively and shaken evenly until it was dissolved, and cooled down to −10° C. in a nitrogen environment. The bromoacetyl bromide (3.5 mL 40.4 mmol) diluted in 10 ml of dehydrated dichloromethane was added dropwise into a three-necked flask through a syringe, and stirred for 1 hour, heated up to 5° C., 15° C., and 25° C. for 1 hour each, then heated to 30° C. for 24-hour oscillatory reaction. 50 mL of deionized water was added, and then it was extracted three times with dichloromethane, and dried with anhydrous sodium sulfate. After filtration and rotary evaporation, the product was purified by silica gel chromatography (dichloromethane:n-hexane=1:1, v/v) to obtain 3.21 g of octyl bromoacetate with a yield of 62%; dodecyl bromoacetate 3.62 g, with a yield of 59%; tetradecyl bromoacetate 3.15 g, with a yield of 47%; octadecyl bromoacetate 3.28 g, with a yield of 42%.
Octyl Bromoacetate: Product FT-IR (KBr, cm−1): 2971 (C—H); 1744 (C—O); 1249 (CO—O); 1141 (O—C—C). 1HNMR (400 MHZ, CDCl3): 4.10 (Br—CH2); 4.33 (—CH2) ppm.
Dodecyl Bromoacetate: Product FT-IR (KBr, cm−1): 3120, 2981 (C—H); 1751 (C═O); 1402 (—CH2); 1285 (CO—O); 1135 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.14 (Br—CH2); 4.38 (—CH2) ppm.
Tetradecyl Bromoacetate: Product FT-IR (KBr, cm−1): 3142, 3083 (C—H); 1851 (C═O); 1433 (—CH2); 1011 (CO—O); 1201 (O—C—C); 1H NMR (400 MHZ, CDCl3): 4.09 (Br—CH2); 4.28 (—CH2) ppm.
Octadecyl Bromoacetate: Product FT-IR (KBr, cm−1): 3128, 2963 (C—H); 1737 (C═O); 1411 (—CH2); 1183 (CO—O); 1182 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.10 (Br—CH2); 4.17 (—CH2) ppm.
(2) The synthesis of capryl diazoacetate, dodexyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate: the above four products were dissolved in 100 mL of dehydrated tetrahydrofuran, 8.85 g (23 mmol) of N, N′-toluenesulfonyl hydrazine was added and cooled down to 0° C. 6.70 mL (44.8 mmol) of DBU was added under nitrogen protection, heated up to the room temperature, and stirred for 24 hours. 20 mL of deionized water was added, and it was extracted three times with dichloromethane, and dried with anhydrous magnesium sulfate. After filtration and rotary evaporation, it was purified by silica gel chromatography (ethyl acetate: dichloromethane=1:5, v/v) to obtain 1.28 g of dark brown oily product of Capryl diazoacetate (CDA) with a yield of 54%; 1.46 g of brown oily product Dodecyl diazoacetate (DDA) with a yield of 48%; 1.04 g of yellow oily product Myristyl diazoacetate (MDA) with a yield of 41%; 1.21 g of light-yellow oily product octadecyl diazoacetate (ODA) with a yield of 45%.
CDA: Product FT-IR (KBr, cm−1): 3119, 2959 (C—H); 2117 (C═N2); 1721 (C═O); 1264 (CO—O); 1077 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.37 (—CH2); 4.72 (H—C═N2) ppm.
DDA: Product FT-IR (KBr, cm−1): 2944 (C—H); 2131 (C═N2) 1728 (C—O); 1411 (—CH2); 1228 (CO—O); 1234 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.46 (—CH2); 4.78 (H—C═N2) ppm.
MDA: Product FT-IR (KBr, cm−1): 3122, 3063, 2956 (C—H); 2228 (C═N2); 1741 (C═O); 1401 (—CH2); 1245 (CO—O); 1024 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.44 (—CH2); 4.79 (H—C═N2) ppm.
ODA: Product FT-IR (KBr, cm−1): 3142, 2978, 2912 (C—H); 2223 (C═N2); 1731 (C═O); 1405 (—CH2); 1246 (CO—O); 1041 (O—C—C). 1H NMR (400 MHZ, CDCl3): 4.43 (—CH2); 4.62 (H—C═N2) ppm.
100 g of sodium hydroxide and 500 ml of deionized water were added to a 1000 ml beaker, and stirred until it was dissolved. The untreated cotton fabric was immersed in the solution for 1 hour, and then it was taken out and washed with deionized water five times, then the alkalized cotton fabric was put in and soaked in 5% acetic acid for 30 minutes, and washed with deionized water five times to obtain the pretreated fabric to be dried at room temperature for standby.
The pretreated fabric (0.415 g) was soaked in anhydrous tetrahydrofuran, and subjected to the ultrasonic cleaning for 30 minutes, and dried at room temperature for standby. The pretreated fabric was put into a conical flask containing 100 mL of anhydrous tetrahydrofuran. After the fabric was completely soaked, 0.83 g of sodium bicarbonate was used as an acid binding agent. The nitrogen gas was let in to empty the air in the flask to cool down to −5° C. After the temperature became stable, 3.25 g of bromoacetyl bromide was dissolved in 5 ml of dehydrated tetrahydrofuran, and then it was added to a conical flask through an injector for 1-hour reaction. Then the temperature was raised to 10° C. for 1-hour reaction. After that, the temperature was raised to 25° C. for 24-hour reaction. The fabric was taken out and washed with tetrahydrofuran and dried to obtain the treated cotton fabric. The SEM-EDS image of the fiber surface is shown in
The treated cotton fabric was put into a conical flask, 50 mL of anhydrous tetrahydrofuran and 2.71 g 1,2-bis (p-Toluenesulfonyl) hydrazine were added, and the nitrogen gas was let in to empty the air in the flask, then it was transferred to a low-temperature reactor to cool to −10° C. DBU dissolved in 10 ml anhydrous tetrahydrofuran was added dropwise into a conical flask through an injector. The flask was shaken until 1,2-bis(p-Toluenesulfonyl) hydrazine was completely dissolved, and the solution gradually turned yellow. Then the temperature was raised to 0° C. for 1-hour reaction. After that, the temperature was raised to 25° C. for 24-hour reaction. The fabric was taken out and washed with tetrahydrofuran and dried to obtain the diazotized cotton fabric. The SEM-EDS image of the fiber surface is shown in
0.26 g of the above diazotized cotton fabric (containing 2 mmol of hydroxyl groups) was taken and added into a 150 ml conical flask. Then 20 mmol of hexyl diazoacetate monomer was added and 100 mL anhydrous tetrahydrofuran was used as the solvent. The molar ratio of the monomer to the surface hydroxyl group of the diazotized cotton fabric in the flask was 10:1. Under the nitrogen condition, 9.15 mg (0.025 mmol) (π-allylPdCl) 2 was added and cooled down to −10° C. Then NaBPh4 32.5 mg (0.09 mmol) was added and dissolved and then heated up to 0° C., 5° C. and 15° C. for 1-hour reaction respectively. Finally, the conical flask was transferred to a reciprocating shaker bath and heated up to 30° C. for a 12-hour reaction. After treatment, the fabric was ultrasonically cleaned in tetrahydrofuran for 2 minutes, and then dried at low temperature in an oven to obtain a hydrophobic fabric with a water contact angle of 105.0°.
0.26 g of the above diazotized cotton fabric (containing 2 mmol of hydroxyl groups) from the Example 1 was taken and added into a 150 ml conical flask. Then 40 mmol of hexyl diazoacetate monomer was added and 100 mL anhydrous tetrahydrofuran was used as the solvent. The molar ratio of the monomer to the surface hydroxyl group of the diazotized cotton fabric in the flask was 20:1. Under the nitrogen condition, 9.15 mg (0.025 mmol) (π-allylPdCl) 2 was added and cooled down to −10° C. Then NaBPh4 32.5 mg (0.09 mmol) was added and dissolved and then heated up to 0° C., 5° C. and 15° C. for 1-hour reaction respectively. Finally, the conical flask was transferred to a reciprocating shaker bath and heated up to 30° C. for a 12-hour reaction. After treatment, the fabric was ultrasonically cleaned in tetrahydrofuran for 2 minutes, and then dried at low temperature in an oven to obtain a hydrophobic fabric with a water contact angle of 110.4°.
0.26 g of the above diazotized cotton fabric (containing 2 mmol of hydroxyl groups) from the Example 1 was taken and added into a 150 ml conical flask. Then 60 mmol of hexyl diazoacetate monomer was added and 100 mL anhydrous tetrahydrofuran was used as the solvent. The molar ratio of the monomer to the surface hydroxyl group of the diazotized cotton fabric in the flask was 30:1. Under the nitrogen condition, 9.15 mg (0.025 mmol) (π-allylPdCl) 2 was added and cooled down to −10° C. Then NaBPh4 32.5 mg (0.09 mmol) was added and dissolved and then heated up to 0° C., 5° C. and 15° C. for 1-hour reaction respectively. Finally, the conical flask was transferred to a reciprocating shaker bath and heated up to 30° C. for a 12-hour reaction. After treatment, the fabric was ultrasonically cleaned in tetrahydrofuran for 2 minutes, and then dried at low temperature in an oven to obtain a hydrophobic fabric with a water contact angle of 118°; the air permeability was 124.3±3.0 mm·s−1.
0.26 g of the above diazotized cotton fabric (containing 2 mmol of hydroxyl groups) from the Example 1 was taken and added into a 150 ml conical flask. Then 60 mmol of hexyl diazoacetate monomer was added and 100 mL anhydrous tetrahydrofuran was used as the solvent. The molar ratio of the monomer to the surface hydroxyl group of the diazotized cotton fabric in the flask was 30:1. Under the nitrogen condition, 9.15 mg (0.025 mmol) (π-allylPdCl) 2 was added and cooled down to −10° C. Then NaBPh4 32.5 mg (0.09 mmol) was added and dissolved and then heated up to 0° C., 5° C. and 15° C. for 1-hour reaction respectively. Finally, the conical flask was transferred to a reciprocating shaker bath and heated up to 30° C. for a 24-hour reaction. After treatment, the fabric was ultrasonically cleaned in tetrahydrofuran for 2 minutes, and then dried at low temperature in an oven to obtain a hydrophobic fabric with a water contact angle of 124°. The infrared total reflectance (ATR) and surface EDS scanning images of cotton fabric before and after carbene grafting with hexyl diazoacetate were shown in
0.26 g of the above diazotized cotton fabric (containing 2 mmol of hydroxyl groups) from the Example 1 was taken and added into a 150 ml conical flask. Then 60 mmol of hexyl diazoacetate monomer was added and 100 mL anhydrous tetrahydrofuran was used as the solvent. The molar ratio of the monomer to the surface hydroxyl group of the diazotized cotton fabric in the flask was 30:1. Under the nitrogen condition, 9.15 mg (0.025 mmol) (π-allylPdCl) 2 was added and cooled down to −10° C. Then NaBPh4 32.5 mg (0.09 mmol) was added and dissolved and then heated up to 0° C., 5° C. and 15° C. for 1-hour reaction respectively. Finally, the conical flask was transferred to a reciprocating shaker bath and heated up to 30° C. for a 36-hour reaction. After treatment, the fabric was ultrasonically cleaned in tetrahydrofuran for 2 minutes, and then dried at low temperature in an oven to obtain a hydrophobic fabric with a water contact angle of 123°. The SEM morphology of the fiber surface was shown in
60 mmol of the above five kinds of diazoacetate monomers (BDA, CDA, DDA, MDA, ODA) were diluted in 150 mL of dehydrated tetrahydrofuran solution, and 9.15 mg (25 μmol) (π-allylPdCl) 2 was added to the solution and stirred well. Then the solution was transferred to a conical flask and 0.26 g of diazotized cotton fabric (containing about 2 mmol of hydroxyl) from the Example 1 was added. After that, it was cooled down to −10° C. in a low-temperature reactor and a nitrogen gas atmosphere, and 32.5 mg (0.09 mmol) of NaBPh4 was added. Next, it was heated up to 0° C., 10° C., 20° C. for 1-hour reaction respectively. Finally, it was transferred to a shaking water bath at 30° C. to react for 24 hours. After the reaction was completed, the fabric was taken out and washed with deionized water and ethanol respectively, and dried at 50° C. to obtain the hydrophobic fabric with the water contact angles of 116.2° (BDA), 129.3 º (CDA), 130.1° (DDA), 131.2° (MDA), 133.4° (ODA). The water contact angles of cotton fabrics carbene grafted with butyl diazoacetate and hexyl diazoacetate were 116.2° and 124.0°, respectively. However, the water contact angle of cotton fabrics carbene grafted with capryl diazoacetate increased rapidly to 129.3°. This was because the latter could also give the fiber surface a certain roughened structure during grafting modification, and the synergistic effect of chemical composition and physical structure on the modified fiber surface provided good hydrophobicity. Furthermore, when carbene grafting was performed on cotton fabric using dodecyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate as monomers, it was found that the modified fabric did not significantly improve its water contact angle, indicating that low surface energy was not the only factor leading to changes in hydrophobic properties. The air permeability of the fabric grafted with butyl diazoacetate carbene polymerization was 137.5±1.7 mm·s−1, and the air permeability of the fabric grafted with capryl diazoacetate carbene polymerization was 112.2±2.4 mm·s−1. When the fabric was treated with dodexyl diazoacetate, myristyl diazoacetate, and octadexyl diazoacetate respectively, the air permeability decreased significantly to be 67.2±0.9 mm·s−1, 58.9±1.3 mm·s−1, and 66.4±2.8 mm·s−1, respectively.
The above-mentioned butyl diazoacetate (b), capryl diazoacetate (c), dodexyl diazoacetate (d), myristyl diazoacetate (e), and octadexyl diazoacetate (f) were used as monomers to perform carbene polymerization grafting modification on cotton fabric (a). The attenuated total reflection infrared (ATR) and X-ray photoelectron spectroscopy (XPS) spectra of the modified fibers were shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210138213.5 | Feb 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2022/091887 | 5/10/2022 | WO |
