WATER-REPELLENT FABRIC AND PREPARATION METHOD THEREFOR
20230323593 · 2023-10-12
Inventors
Cpc classification
D06M15/37
TEXTILES; PAPER
D06M14/04
TEXTILES; PAPER
International classification
Abstract
Disclosed are a water-repellent fabric and a preparation method therefor. A short carbon chain fluoroalkyl alcohol with different fluorine atom numbers used as a starter is firstly treated with an acylation reagent to generate a short carbon chain fluoroalkyl bromoacetate, and is then synthesized with N,N-bis(p-toluenesulfonyl) hydrazine to form a short carbon chain fluoroalkyl diazoacetate monomer, a fabric is respectively treated with an acylation reagent and N,N″-dimethylbenzenesulfonyl hydrazide in sequence to prepare a diazotized fabric having grafting sites on the surface thereof, and finally, a fluorine-containing polymer having a single carbon repeating unit is grafted to the surface of the fabric via a covalent bond by means of carbene polymerization, and thus a hydrophobic modified fabric is prepared. The entire reaction is carried out at a low temperature/room temperature, the operation is simple, and the process is environmentally friendly.
Claims
1. A water-repellent fabric, wherein: the water-repellent fabric comprises a fabric and a covalent grafting fluoropolymer by carbene polymerization on the surface of the fabric.
2. The water-repellent fabric according to the claim 1, wherein: the structural formula of the covalent grafting fluoropolymer by carbene polymerization is as follows: ##STR00007## Rf represents fluoroalkyl.
3. The water-repellent fabric according to the claim 2, wherein: a fluorine atom number of the fluoroalkyl is 3-15.
4. The water-repellent fabric according to the claim 1 is applied in the preparation of waterproof materials.
5. A preparation method of the water-repellent fabric according to the claim 1, wherein: the method comprises the following steps: under the action of a catalyst, place the fluoroalkyl diazoacetate and the active fabric in an organic solvent, and the fluoropolymer is covalently grafted to the fiber surface of the fabric by means of carbene polymerization to obtain the water-repellent fabric; the active fabric is a fabric containing a grafting site.
6. The preparation method of the water-repellent fabric according to the claim 5, wherein: a fluorine atom number in the fluoroalkyl diazoacetate is 3-15; the grafting site is diazo.
7. The preparation method of the water-repellent fabric according to the claim 5, wherein: the catalyst is palladium chloride; the organic solvent is one or more of tetrahydrofuran, dichloromethane and ethanol; the carbene polymerization is carried out under oscillation or stirring.
8. The preparation method of the water-repellent fabric according to the claim 5, wherein: the fluoroalkyl alcohol reacts with bromoacetyl bromide to obtain fluoroalkyl bromoacetate, and then fluoroalkyl bromoacetate reacts with N,N″-dimethylbenzenesulfonyl hydrazide to obtain fluoroalkyl diazoacetate; the fabric is acylated and then reacted with N,N″-dimethylbenzenesulfonyl hydrazide to prepare the active fabric.
9. The preparation method of the water-repellent fabric according to the claim 8, wherein: the reaction of fluoroalkyl alcohol and bromoacetyl bromide is carried out in the presence of alkali; the reaction of fluoroalkyl bromoacetate and N,N″-dimethylbenzenesulfonyl hydrazide is carried out in the presence of organic acid binding agent.
10. The preparation method of the water-repellent fabric according to the claim 8, wherein: the fluorine atom number of the fluoroalkyl is 3-15.
Description
BRIEF DESCRIPTION OF ATTACHED DRAWINGS
Brief Description of the Drawings
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EXAMPLES OF THE INVENTION
Examples of the Present Invention
[0042] In the present invention, the water-repellent fabric is formed on the surface of the fabric through fluorine-containing polymer by means of carbene polymerization covalent grafting.
[0043] The preparation method of the water-repellent fabric includes the following steps.
[0044] (1) Preparation of bromoacetate: To use short carbon chain fluoroalkyl alcohol containing certain fluorine atom number as the starter, anhydrous tetrahydrofuran as the reaction medium, and react with bromoacetyl bromide under the action of sodium bicarbonate for substitution reaction to generate short carbon chain fluoroalkyl bromoacetate.
[0045] (2) Preparation of diazotate: To dissolve short carbon chain fluoroalkyl bromoacetate and diazo precursor N,N″-dimethylbenzenesulfonyl hydrazide in anhydrous tetrahydrofuran solvent to generate short carbon chain fluoroalkyl diazoacetate under the catalytic reaction of acid-binding agent DBU.
[0046] (3) Preparation of grafting sites on the surface of fibers: To use tetrahydrofuran as solvent, and the surface hydroxyl groups of the fiber are first acylated by acylating agent under the action of acid-binding agent, and then reacted with diazo precursor N,N″-dimethylbenzenesulfonyl hydrazide to prepare the active fiber containing grafting sites.
[0047] (4) Carbene polymerization covalent grafting: Placing the short carbon chain fluoroalkyl diazoacetate and active fiber in the organic solvent, and under the action of catalyst, the polymer crystal roughening structures with different morphologies and sizes can be prepared on the surface of the fiber by carbene polymerization under different conditions.
[0048] The specific steps are as follows:
[0049] (1) Synthesis of short carbon chain fluoroalkyl bromoacetate.
##STR00003##
[0050] Under the protection of nitrogen, take dehydrated tetrahydrofuran as the reaction medium. Put short carbon chain fluoroalkyl alcohol and sodium bicarbonate into a three-necked flask, and slowly added bromoacetyl bromide into the mixture dropwise at low temperature (feeding proportion of 1:1.5:3 mol) for reaction. After the reaction, make quenching reaction with deionized water, then added saturated sodium bicarbonate solution, extract with dichloromethane, drying with anhydrous magnesium sulfate, to obtain the product by removing the low boiling point solvent by means of suction filtration and rotary evaporation.
[0051] (2) Synthesis of short carbon chain fluoroalkyl diazoacetate.
##STR00004##
[0052] Under the protection of nitrogen, take dehydrated tetrahydrofuran as the reaction medium and added short carbon chain fluoroalkyl bromoacetate and N,N-bis(p-toluenesulfonyl) hydrazine into a three-necked flask, and added DBU into the mixture dropwise at low temperature for reaction at constant temperature for a certain time (feeding proportion of 1:2:5 mol). After the reaction, make quenching reaction with deionized water, then added saturated sodium bicarbonate solution, extract with trichloromethane, drying with anhydrous magnesium sulfate, to obtain the product by removing the low boiling point solvent by means of suction filtration and rotary evaporation.
[0053] (3) Generation of grafting sites on the fiber surface.
##STR00005##
[0054] Under the protection of nitrogen, take dehydrated tetrahydrofuran as the reaction medium, added sodium bicarbonate and cotton fabric into the conical flask, added bromoacetyl bromide dropwise at low temperature, and then placing it at normal temperature for reaction. After the reaction, cleaning the fabric with tetrahydrofuran and deionized water respectively, and drying at low temperature. Then putting the dried fabric and N,N-bis(p-toluenesulfonyl) hydrazine into the reactor, and added DBU dropwise into the mixture at low temperature for reaction at constant temperature. After the reaction, cleaning the fabric with tetrahydrofuran and deionized water respectively, and drying at low temperature for standby.
[0055] (4) Covalent grafting fluorine-containing polymer to fiber surface by carbene polymerization
##STR00006##
[0056] Under the protection of nitrogen, taking dehydrated tetrahydrofuran, dichloromethane, toluene, and the mixture of dehydrated tetrahydrofuran and anhydrous ethanol as the reaction media. Placing the monomer, active fiber and NaBPh.sub.4 in a conical flask containing reaction media at room temperature, added (π-allylPdCl).sub.2 at low temperature, and then react at constant temperature under stable dynamic mode. After the reaction, cleaning the cotton fabric with tetrahydrofuran and deionized water respectively, and drying at low temperature to obtain water-repellent fabric.
[0057] The raw materials involved are all commercially available conventional products, and the fabric is conventional cotton fabric subject to conventional alkaline treatment; the specific operation method and test method are conventional techniques. With reference to the accompanying drawings and Example, the technical scheme of the present invention will be described in detail. Pretreatment of cotton fabric: at room temperature, immersing the conventional cotton fabric in sodium hydroxide solution with mass fraction of 20% for 25 min, washing it with distilled water three times, immersing it in 5% glacial acetic acid for 30 min, washing it to neutral with deionized water and drying to obtain alkalized cotton fabric to be used in.
Example 1
[0058] (1) Synthesis of trifluoropropyl diazoacetate:
[0059] Added 50 mL of anhydrous tetrahydrofuran, 0.57 g of 3,3,3-trifluoro-1-propanol and 1.26 g of sodium bicarbonate into a three-necked flask and cold it to 0° C. Under nitrogen dropped 1.54 g of bromoacetyl bromide in at constant temperature for 3 h. After the reaction, quenched with deionized water, then added saturated sodium bicarbonate solution, extracted with dichloromethane, dried with anhydrous magnesium sulfate, and to obtain 1.17 g of intermediate trifluoropropyl bromoacetate, with a yield of 89% by removing the low boiling point solvent by means of suction filtration and rotary evaporation. Put the prepared intermediate into a three-necked flask containing 60 mL of anhydrous tetrahydrofuran, added 3.41 g of N,N-bis(p-toluenesulfonyl) hydrazine and cold it to 0° C., and added 3.82 g of DBU dropwise into the mixed solution under nitrogen for reaction for 3 h. After the reaction, make quenching reaction with deionized water, then added saturated sodium bicarbonate solution, extract with dichloromethane 3 times, dried with anhydrous magnesium sulfate, to obtain 0.68 g product with a yield of 75% by removing the low boiling point solvent by means of suction filtration and rotary evaporation.
[0060] (2) Generation of grafting sites on the fiber surface: put 0.815 g of cotton fabric into a conical flask containing 50 mL of anhydrous tetrahydrofuran and 1.68 g of sodium bicarbonate, cold it to 0° C., added 1.68 g of bromoacetyl bromide under nitrogen for reaction at constant temperature for 30 min, and then put it in a shaker bath to naturally raise the temperature to 30° C. for reaction at constant temperature for 15 hours, and then washed it with tetrahydrofuran and deionized water respectively, and dried it to obtain brominated fabric. Immersed the brominated fabric in a conical flask containing anhydrous tetrahydrofuran, added 5.11 g of N,N-bis(p-toluenesulfonyl) hydrazine, cold it to 0° C., added 4.57 g of DBU under nitrogen, and react at 0° C. for 30 min, finally placed it in a shaker bath to naturally raise the temperature to 30° C. for oscillatory reaction at constant temperature for 20 hours. After the reaction, cleaned the fabric having grafting sites with tetrahydrofuran and deionized water respectively, and dried it for step (3).
[0061] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized trifluoropropyl diazoacetate into a conical flask containing 60 mL of anhydrous tetrahydrofuran, immersed the fabric having grafting sites into the flask, added 9.15 mg (π-allylPdCl).sub.2, then cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for oscillatory reaction for 1 h, then raise the temperature to 10° C. for reaction for 1 h, raise the temperature to 20° C. for reaction for 1 h, and finally raise the temperature to 30° C. for reaction for 24 h. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C. to obtain the water-repellent fabric.
[0062] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0063] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 2
[0064] (1) Synthesis of nonafluorohexyl diazoacetate: added 50 mL of anhydrous tetrahydrofuran, 1.32 g of perfluorobutyl ethanol and 1.26 g of sodium bicarbonate into a three-necked flask and cold it to 0° C., Added 1.54 g of bromoacetyl bromide under nitrogen, and make purification at constant temperature for 3 h to obtain 1.75 g of intermediate nonafluorohexyl diazoacetate. Then put the prepared intermediate into a three-necked flask containing 60 mL of anhydrous tetrahydrofuran, added 3.41 g of N,N-bis(p-toluenesulfonyl) hydrazine and cold it to 0° C., and added 3.82 g of DBU dropwise into the mixed solution under nitrogen for reaction for 3 h. After the reaction, make quenching reaction with deionized water, extract with dichloromethane 3 times, dried with anhydrous magnesium sulfate, to obtain 1.29 g product with a yield of 78% by removing the low boiling point solvent by means of suction filtration and rotary evaporation.
[0065] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0066] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized nonafluorohexyl diazoacetate in step (1) into a conical flask containing 60 mL of anhydrous tetrahydrofuran, immersed the fabric having grafting sites into the flask, added 9.15 mg (π-allylPdCl).sub.2, then put it in a low-temperature reactor and cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for slow oscillation for 1 h, then react for 1 h at 10° C., react for 1 h at 20° C., and react for 24 h at 30° C. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0067] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0068] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 3
[0069] (1) Synthesis of nonafluorohexyl diazoacetate: Consistent with the Example 2.
[0070] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0071] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized nonafluorohexyl diazoacetate in step (1) into a round-bottom flask containing 60 mL of anhydrous tetrahydrofuran, fixed the fabric having grafting sites on the bottom of the stirring paddedle and immersed it into the flask, added 9.15 mg (π-allylPdCl).sub.2, then put it in a low-temperature reactor and cold to −10° C., and added 32.5 mg of NaBPh.sub.12; react for 1 h at 0° C. under dynamic stirring (fabric rotation, strength similar to that in Example 2, then reacted for 1 h at 10° C., reacted for 1 h at 20° C., and reacted for 12 h at 30° C. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0072] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 4
[0073] (1) Synthesis of nonafluorohexyl diazoacetate: Consistent with the Example 2.
[0074] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0075] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized nonafluorohexyl diazoacetate in step (1) into a conical flask containing 60 mL of anhydrous toluene, immersed the fabric having grafting sites into the flask, added 9.15 mg (π-allylPdCl).sub.2, then put it in a low-temperature reactor and cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for slow oscillation for 1 h, then reacted for 1 h at 10° C., reacted for 1 h at 20° C., and reacted for 24 h at 30° C. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0076] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0077] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 5
[0078] (1) Synthesis of nonafluorohexyl diazoacetate: Consistent with the Example 2.
[0079] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0080] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized nonafluorohexyl diazoacetate in step (1) into a conical flask containing 60 mL of anhydrous dichloromethane, immersed the fabric having grafting sites into the flask, added 9.15 mg (π-allylPdCl).sub.2, then put it in a low-temperature reactor and cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for slow oscillation for 1 h, then reacted for 1 h at 10° C., reacted for 1 h at 20° C., and reacted for 24 h at 30° C. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0081] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0082] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 6
[0083] (1) Synthesis of nonafluorohexyl diazoacetate: Consistent with the Example 2.
[0084] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0085] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized nonafluorohexyl diazoacetate in step (1) into a conical flask containing 50 mL of anhydrous tetrahydrofuran and 10 mL of anhydrous ethanol mixture, immersed the fabric having grafting sites into the flask, added 9.15 mg (π-allylPdCl).sub.2, then put it in a low-temperature reactor and cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for slow oscillation for 1 h, then reacted for 1 h at 10° C., reacted for 1 h at 20° C., and reacted for 24 h at 30° C. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0086] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0087] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 7
[0088] (1) Synthesis of tridecafluorooctyl diazoacetate: added 50 mL of anhydrous tetrahydrofuran, 1.82 g of perfluorohexyl ethanol and 1.26 g of sodium bicarbonate into a three-necked flask and cold it to 0° C. Added 1.54 g of bromoacetyl bromide under nitrogen, and make reaction at constant temperature for 3 h to obtain 2.09 g of intermediate tridecafluorooctyl diazoacetate. Then put the prepared intermediate into a three-necked flask containing 60 mL of anhydrous tetrahydrofuran, added 3.41 g of N,N-bis(p-toluenesulfonyl) hydrazine and cold it to 0° C., and added 3.82 g of DBU under nitrogen for reaction for 3 h. After the reaction, make quenching reaction with deionized water, extract with dichloromethane 3 times, dried with anhydrous magnesium sulfate, to obtain 1.64 g product with a yield of 76% by removing the low boiling point solvent by means of suction filtration and rotary evaporation.
[0089] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0090] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized tridecafluorooctyl diazoacetate into a conical flask containing 60 mL of anhydrous tetrahydrofuran, immersed the fabric having grafting sites into the flask, added 9.15 mg (T-allylPdCl).sub.2, then cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for slow oscillation for 1 h, then reacted for 1 h at 10° C., reacted for 1 h at 20° C., and reacted for 24 h at 30° C. After the reaction, cleaned the fabric of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0091] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0092] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
Example 8
[0093] (1) Synthesis of tridecafluorooctyl diazoacetate: Consistent with the Example 7.
[0094] (2) Generation of grafting sites on the fiber surface: Consistent with the Example 1.
[0095] (3) Preparation of hydrophobic fabric: Added 5 mmol of the synthesized tridecafluorooctyl diazoacetate in step (1) into a conical flask containing 50 mL of anhydrous tetrahydrofuran and 10 mL of anhydrous ethanol mixture, immersed the fabric having grafting sites into the flask, added 9.15 mg (π-allylPdCl).sub.2, then put it in a low-temperature reactor and cold to −10° C., and added 32.5 mg of NaBPh.sub.4. Moved the conical flask into the shaker bath at 0° C. for slow oscillation for 1 h, then reacted for 1 h at 10° C., reacted for 1 h at 20° C., and reacted for 24 h at 30° C. After the reaction, cleaned the fabric Polymer-cotton of graft polymer with ethanol and deionized water respectively, and dried it at 50° C.
[0096] Adjusted the above final reaction at 30° C. for 24 h to the reaction at 30° C. for 12 h, and kept the other conditions unchanged to obtain the water-repellent fabric.
[0097] (4) Contact angle test: used the OCAH200 Microscopic Droplet Wettability Tester from American Dataphysics to test the wettability of the grafted functional fabric, selected water as the test droplet, and the volume of the droplet was 5 μL and taken the average of five tests.
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[0112] The adhesion between the solid surface and the liquid droplet is one of the important parameters to measure the anti-wettability function of the fabric. The chemical composition of the solid surface not only affects the static contact angle, but also has a considerable impact on the dynamic adhesion. The adhesion of the surface to water is different for either the highly hydrophobic or super-hydrophobic surface. In the adhesion curve, the adhesion of the surface of raw cotton fabric to water is more than 140 uN, while it can be seen from
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[0114] The invention discloses a water-repellent fabric, which expands the application research of carbene polymerization in the field of preparation of functional materials. Based on the single-carbon repetition and tridimensional regularity characteristics of a carbene polymer, the novel carbene polymerization covalent grafting can construct low surface energy roughening structures on the surface of the fabric in one step, which doesn't require the traditional organic-inorganic hybridization and multi-step reaction and can obtain the relatively durable hydrophobic effect. The novel carbene polymerization (C.sub.1 polymerization) can graft the low surface energy polymer based on the single carbon repeating unit to the cotton fabric, and utilizes the molecular chain rigidity of the densely stacked single carbon units, so it is expected to induce the carbene polymer crystallization on the fiber surface to form polymer crystal structures with roughening morphologies on the surface of fabric by self-assembly driven by crystallization, thus obtaining the required protective physical structures. The process of carbene polymerization grafting is carried out at low/room temperature. Compared with other modification methods that need to be carried out at high temperature/high pressure or under strong acid/alkali or strong oxidant conditions, it achieves the minimum damage to the fiber and the by-product of polymerization is nitrogen, which is relatively environmentally friendly.