Super-hydrophobic modified viscose fabric and preparation method thereof

Abstract

The application discloses a preparation method of super-hydrophobic modified Tencel fabric, comprising the following steps: immersing the pretreated Tencel fabric into an acetic acid solution of chitosan, then controlling the liquid rate of the fabric surface to be 70%-90%; performing heat treatment on the Tencel fabric with the chitosan solution; immersing the heat-treated Tencel fabric into an aqueous solution of zinc acetate dihydrate for 0.1-0.5 hours, then adding an aqueous solution of dimethyl imidazole, stirring and standing for reaction, taking out the Tencel fabric after the reaction, washing and drying; immersing the dried Tencel fabric into an ethanol solution of tung oil and standing, then controlling the liquid rate of the fabric surface to be 40%-70%; taking out the Tencel fabric, washing and drying, and placing in air for 10-30 days to obtain the super-hydrophobic modified Tencel fabric. The preparation method is based on chitosan, zeolite imidazolate framework material and tung oil, the super-hydrophobic modified Tencel fabric has the super-hydrophobic effect compared with the unmodified Tencel fabric, and the hydrophobic property of the super-hydrophobic modified Tencel fabric is improved with the increase of the number of soaping.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fabric modification and processing technology, in particular to a preparation method of super-hydrophobic modification of Tencel fabric by using tung oil, chitosan and zeolitic imidazolate framework (ZIF-8), and a super-hydrophobic modified Tencel fabric prepared by using the preparation method, which has an initial surface contact angle of greater than or equal to 145°. BACKGROUND

[0002] Tencel fabric is a comfortable, breathable, renewable and biodegradable excellent material, which provides an environmentally friendly and sustainable plant-based alternative to synthetic materials. With the progress of the times, consumers increasingly prefer functional fabric materials. Among them, super-hydrophobic Tencel fabric has unique properties such as stain resistance and self-cleaning, and has broad application prospects in high-end neckties, scarves, tablecloths and home goods, and can solve the problem of poor water resistance of sand-washing lyocell fabric in woven garment fabric.

[0003] Tencel belongs to regenerated cellulose fiber, and its super-hydrophobic modification method mainly learns from the modification method of cotton fabric. The materials used in the existing method of super-hydrophobic modification of cotton fabric have certain harm to the environment, such as using long-chain fluorine-containing reagents to modify the hydrophobicity of the fabric. Long-chain fluorine-containing reagents have strong stability and are difficult to degrade, which will cause irreparable damage to the environment and human body. Currently, long-chain fluorine-containing reagents have been gradually banned. Zeolitic imidazolate framework material (ZIF-8) is a popular material that has emerged in recent years and is widely used in catalysis, adsorption and sensing fields. However, the application of ZIF-8 in the functional modification of textiles is currently less studied.

[0004] In addition, the super-hydrophobic modified fabric reported at present still has a big defect in fastness (such as soaping fastness). Therefore, it is a direction worth studying to find more environmentally friendly materials to prepare super-hydrophobic Tencel fabric with strong durability. In previous reports, researchers often start from improving the fastness between the modified reagent and the substrate to improve the durability of super-hydrophobic fabric, such as establishing a covalent bond between the modified reagent and the substrate. The fabric treated in this way has been significantly improved in soaping fastness. However, the use of the action between the soaping liquid and the hydrophobic coating of the fabric to improve the soaping fastness has not been reported.

[0005] The disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present patent application. In the absence of explicit evidence that the above content has been disclosed before the filing date of the present patent application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0006] In view of this, in order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing a superhydrophobic modified Tencel fabric, so as to obtain a superhydrophobic modified Tencel fabric with an initial surface contact angle greater than or equal to 145°, and whose hydrophobic properties can be improved with the increase of the number of soaping cycles.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A method for preparing superhydrophobic modified Tencel fabric includes the following steps:

[0009] The pretreated Tencel fabric was immersed in an acetic acid solution of chitosan, and then the liquid content on the fabric surface was controlled to be 70%-90%.

[0010] The Tencel fabric containing chitosan solution is subjected to heat treatment at a temperature of 140-160°C for 1-5 minutes.

[0011] The heat-treated Tencel fabric was immersed in an aqueous solution of zinc acetate dihydrate for 0.1-0.5 hours, then an aqueous solution of dimethylimidazole was added, stirred, and allowed to stand for reaction. After the reaction was completed, the Tencel fabric was removed, washed with water, and dried. ZIF-8 was grown in situ. The introduction of ZIF-8 into the surface of textiles can significantly increase the surface roughness and endow the textiles with hydrophobic properties.

[0012] The dried Tencel fabric was immersed in an ethanol solution of tung oil and left to stand, and then the liquid content on the fabric surface was controlled to be 40%-70%.

[0013] Remove the Tencel fabric, wash and dry it, and leave it in the air for 10-30 days to obtain the superhydrophobic modified Tencel fabric. The superhydrophobic modified Tencel fabric is prepared in a way that utilizes the interaction between the soaping solution and the hydrophobic coating of the Tencel fabric to improve its soaping fastness.

[0014] According to some preferred embodiments of the present invention, the acetic acid solution of chitosan is formed by dissolving chitosan in an acetic acid solution with a concentration of 1%-3%, wherein the concentration of chitosan in the acetic acid solution of chitosan is 2%-4%.

[0015] According to some preferred embodiments of the invention, the heat treatment is performed on the Tencel fabric containing the chitosan solution using a hot press or a flatbed heat press.

[0016] According to some preferred embodiments of the present invention, the concentration of the aqueous solution of zinc acetate dihydrate is 1%-2%; and the concentration of the aqueous solution of dimethylimidazole is 15%-20%.

[0017] According to some preferred embodiments of the invention, the reaction is allowed to stand after stirring for 0.1-1 hours and then allowed to stand for 12-36 hours.

[0018] According to some preferred embodiments of the present application, the concentration of tung oil in the ethanol solution of tung oil is 1%-3%; the standing time is 2-10 minutes.

[0019] According to some preferred embodiments of the present application, the pretreatment is as follows: the Tencel fabric is added to a solution composed of soap flakes, sodium carbonate and deionized water, gradually heated to 65-75°C under stirring, and incubated; after the end, the Tencel fabric is taken out, washed repeatedly with deionized water and dried, and equilibrated at room temperature for 10-16h, to obtain clean Tencel fabric.

[0020] According to some preferred embodiments of the present application, the surface contact angle of the prepared super-hydrophobic modified Tencel fabric is 145°-150°.

[0021] In some embodiments of the present application, the preparation method of the super-hydrophobic modified Tencel fabric specifically comprises the following steps:

[0022] (1) Pretreatment: the Tencel fabric is added to a solution composed of soap flakes, sodium carbonate and deionized water, gradually heated to 65-75°C under stirring, and incubated; after the end, the Tencel fabric is taken out, washed repeatedly with deionized water and dried, and equilibrated at room temperature for 10-16h, to obtain clean Tencel fabric.

[0023] (2) Chitosan is dissolved in an acetic acid solution with a concentration of 1-3% to form a chitosan acetic acid solution with a chitosan concentration of 2-4%. Then the pretreated Tencel fabric is immersed in it and stirred for 5-15 minutes.

[0024] (3) The Tencel fabric is taken out, and the liquid rate on the fabric surface is controlled to be 70%-90% using a mangle.

[0025] (4) The Tencel fabric with chitosan solution is heat treated in a hot press or a flat bed press for 1-5 minutes, and the heat treatment temperature is 140-160°C.

[0026] (5) The heat treated Tencel fabric is immersed in a zinc acetate dihydrate aqueous solution with a concentration of 1%-2% for 0.1-0.5 hours, then a dimethylimidazole aqueous solution with a concentration of 15%-20% is added, stirred for 0.1-1 hours, and then stood for 12-36 hours. After the standing treatment, it is washed and dried.

[0027] (6) The dried Tencel fabric is immersed in a tung oil ethanol solution with a concentration of 1%-3%, taken out after 2-10 minutes, and the liquid rate on the fabric surface is controlled to be 40%-70% using a mangle.

[0028] (7) The Tencel fabric is taken out, washed and dried, and then placed in air for 10-30 days, and then the super-hydrophobic modified Tencel fabric is obtained, and the hydrophobic property of the super-hydrophobic modified Tencel fabric is improved with the increase of the number of soaping.

[0029] The application further provides a method for improving the hydrophobic property of the super-hydrophobic modified Tencel fabric, comprising the following steps: soaping the super-hydrophobic modified Tencel fabric, and the number of washing is 1-30 times, preferably 5-20 times, and the surface contact angle of the modified Tencel fabric after soaping can be improved to 150-170 degrees. The soaping method is carried out according to the standard of GB / T 3921-2008 Textiles. Color fastness test. Color fastness to soaping.

[0030] The application further provides a super-hydrophobic modified Tencel fabric prepared by the preparation method, and the hydrophobic property of the super-hydrophobic modified Tencel fabric is improved with the increase of the number of soaping.

[0031] According to some preferred embodiments of the application, the surface contact angle of the super-hydrophobic modified Tencel fabric after soaping is 150-166 degrees. Specifically, the surface contact angle of the super-hydrophobic modified Tencel fabric after 5 times of soaping is 150-153 degrees; the surface contact angle after 10 times of soaping is 153-158 degrees; the surface contact angle after 15 times of soaping is 158-164 degrees; and the surface contact angle after 20 times of soaping is 164-166 degrees.

[0032] The principle of the application is that the Tencel fabric with a large number of hydroxyl groups in the molecular structure is used as a substrate, and ether bonds are formed with chitosan under the action of high-temperature heat treatment; then ZIF-8 is grown in situ to provide the required surface nanostructure for hydrophobic property; finally, tung oil is used for further treatment to provide the required low-surface-energy substance for hydrophobic property. The main component of tung oil is tung oil acid triglyceride, which will be hydrolyzed into unsaturated tung oil acid containing three conjugated double bonds under the action of alkali. Therefore, a large amount of tung oil acid is generated on the surface of the modified hydrophobic Tencel fabric during the washing process in an alkaline soaping solution. There is electrostatic attraction between the carboxyl groups of the tung oil acid and the ZIF-8. Meanwhile, the tung oil acid can induce the ZIF-8 loaded on the surface of the Tencel fabric to have a nanoflower-like morphology, thereby significantly improving the surface roughness; on the other hand, the generation of the tung oil acid further reduces the surface tension. Under the combined action of the two factors, the contact angle of the Tencel fabric during soaping gradually increases to more than 150 degrees, and the super-hydrophobic property is obtained. And with the continuous increase of the number of soaping, the contact angle of the Tencel fabric can be improved to more than 160 degrees.

[0033] Compared with the prior art, the application has the following advantages: the preparation method of the super-hydrophobic modified Tencel fabric is based on chitosan, zeolite imidazolate framework material and tung oil modification to obtain a Tencel fabric, which has super-hydrophobic effect compared with the unmodified Tencel fabric; the hydrophobic property of the prepared modified Tencel fabric can be gradually improved with the increase of the soaping times, the used materials are non-fluorine, non-toxic and harmless, green and environmentally friendly, and the preparation method is simple. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0035] Figure 1 The surface micro-morphology of the Tencel fabric of Comparative Example 1 (a, only pretreated), Comparative Example 2 (b, chitosan and ZIF-8 modified Tencel fabric), and Example 1 (c, chitosan, ZIF-8 and tung oil modified Tencel fabric);

[0036] Figure 2 The surface contact angle (water) of the Tencel fabric of Comparative Example 1 (only pretreated), Comparative Example 2 (chitosan and ZIF-8 modified Tencel fabric), and Example 1 (chitosan, ZIF-8 and tung oil modified Tencel fabric);

[0037] Figure 3 The surface micro-morphology of the super-hydrophobic modified Tencel fabric prepared in Example 1 after soaping for 5 times (a), 10 times (b), 15 times (c) and 20 times (d);

[0038] Figure 4 The surface contact angle (water) of the super-hydrophobic modified Tencel fabric prepared in Example 1 after soaping for 5 times (a), 10 times (b), 15 times (c) and 20 times (d);

[0039] Figure 5 The surface micro-morphology of the super-hydrophobic modified Tencel fabric prepared in Example 2 (a) and Example 3 (b) after soaping for 5 times. DETAILED DESCRIPTION

[0040] In order to make the technical scheme of the present application better understood by the person skilled in the art, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the present application.

[0041] The lyocell fabric with super-hydrophobicity and the preparation method thereof, the prepared lyocell fabric has super-hydrophobicity, and the hydrophobicity is improved with the increase of the number of soaping, and the super-hydrophobicity is not reduced with the number of soaping. Specifically, the preparation method of the super-hydrophobic modified lyocell fabric comprises the following steps:

[0042] (1) Pretreatment: the lyocell fabric is added into a solution composed of soap chips, sodium carbonate and deionized water, and gradually heated to 65-75 DEG C under stirring, and then kept at this temperature; after the end, the lyocell fabric is taken out, repeatedly washed with deionized water and dried, and then balanced and placed at room temperature for 10-16 hours to obtain clean lyocell fabric.

[0043] (2) The chitosan is dissolved in an acetic acid solution with a concentration of 1-3%, to form a chitosan acetic acid solution with a chitosan concentration of 2-4%. Then the pretreated lyocell fabric is immersed in the solution and stirred for 5-15 minutes.

[0044] (3) The lyocell fabric with chitosan solution is taken out, and the liquid rate of the fabric surface is controlled to be 70%-90% by using a mangle.

[0045] (4) The lyocell fabric with chitosan solution is heat treated in a hot press or a flat press for 1-5 minutes, and the heat treatment temperature is 140-160 DEG C.

[0046] (5) The heat treated lyocell fabric is immersed in a zinc acetate dihydrate aqueous solution with a concentration of 1%-2% for 0.1-0.5 hours, then a dimethylimidazole aqueous solution with a concentration of 15%-20% is added, stirred for 0.1-1 hours, and then placed for 12-36 hours. After the end of the standing treatment, the fabric is washed and dried. The ZIF-8 is in-situ grown; the introduction of ZIF-8 on the surface of the textile can significantly increase the surface roughness and impart hydrophobicity to the textile.

[0047] (6) The dried lyocell fabric is immersed in a tung oil ethanol solution with a concentration of 1%-3%, and then taken out after 2-10 minutes, and the liquid rate of the fabric surface is controlled to be 40%-70% by using a mangle.

[0048] (7) The Tencel fabric was taken out, washed and dried, and then placed in air for 10-30 days, and then a super-hydrophobic modified Tencel fabric was obtained, and the hydrophobic property of the super-hydrophobic modified Tencel fabric was improved with the increase of the number of soaping.

[0049] Pre-treatment:

[0050] Before the Tencel fabric is modified by using chitosan, ZIF-8 and tung oil, the Tencel fabric needs to be pre-treated to remove the dirt and impurities attached to the surface of the Tencel fabric.

[0051] The pre-treatment process in this embodiment is specifically as follows: 2 g of Tencel fabric is added to a solution composed of 0.4 g of soap chips, 0.4 g of sodium carbonate and 200 mL of deionized water, and gradually heated to 70°C under stirring, and kept for 1 h. After the heat preservation treatment, the Tencel fabric is taken out, and washed repeatedly with deionized water for 5 times. Then, the Tencel fabric is dried in a 75°C oven for 6 h, and balanced and placed at room temperature for 12 h, to obtain clean Tencel fabric.

[0052] Example 1

[0053] This embodiment provides a preparation method for modifying the Tencel fabric by using chitosan, ZIF-8 and tung oil to obtain a super-hydrophobic modified Tencel fabric, which specifically comprises the following steps:

[0054] Glacial acetic acid is dissolved in 50 mL of deionized water to obtain an acetic acid solution with a concentration of 2%. Then, 1.55 g of chitosan is dissolved in the obtained acetic acid solution to obtain a chitosan solution with a concentration of 3%.

[0055] 0.25 g of Tencel fabric is immersed in the obtained chitosan solution for 10 minutes, and continuously stirred. Then, the Tencel fabric is taken out, and the liquid rate on the surface of the Tencel fabric is controlled to be 80% by using a mangle.

[0056] The Tencel fabric with the chitosan solution is heat treated in a hot press for 3 minutes, and the heat treatment temperature is 150°C.

[0057] Then, the heat treated Tencel fabric is immersed in an aqueous solution of zinc acetate dihydrate with a concentration of 1.44%, and an aqueous solution of dimethylimidazole with a concentration of 17.22% is added, and stirred for 0.5 hours and then placed for 24 hours. After the standing treatment, the Tencel fabric is washed repeatedly and dried.

[0058] The dried Tencel fabric is immersed in 50 mL of tung oil ethanol solution with a concentration of 2%, and taken out after standing for 5 minutes. After washing and drying, a super-hydrophobic modified Tencel fabric is obtained.

[0059] Example 2

[0060] The embodiment provides a preparation method of functional modification of Tencel fabric by adopting chitosan, ZIF-8 and tung oil to obtain super-hydrophobic modified Tencel fabric, and the difference between the embodiment and example 1 is only that the concentration of the tung oil ethanol solution is different, and the embodiment specifically comprises the following steps.

[0061] Glacial acetic acid is dissolved in 50 mL of deionized water to prepare an acetic acid solution with a concentration of 2%. Then, 1.55 g of chitosan is dissolved in the obtained acetic acid solution to prepare a chitosan solution with a concentration of 3%.

[0062] The obtained chitosan solution is immersed in 0.25 g of Tencel fabric for 10 minutes, and stirring is continuously performed. Then, the Tencel fabric is taken out, and the liquid rate on the surface of the Tencel fabric is controlled to be 80% by means of a mangle.

[0063] The Tencel fabric with the chitosan solution is heat-treated in a hot press for 3 minutes, and the heat treatment temperature is 150 DEG C.

[0064] Then, the heat-treated Tencel fabric is immersed into an aqueous solution of zinc acetate dihydrate with a concentration of 1.44%, and an aqueous solution of dimethylimidazole with a concentration of 17.22% is added, stirring is performed for 0.5 hours, and then standing is performed for 24 hours. After the standing treatment is completed, water washing is repeatedly performed, and drying is performed.

[0065] The dried Tencel fabric is immersed in 50 mL of a tung oil ethanol solution with a concentration of 1%, and then taken out after standing for 5 minutes. After water washing and drying, super-hydrophobic modified Tencel fabric is obtained.

[0066] Example 3

[0067] The embodiment provides a preparation method of functional modification of Tencel fabric by adopting chitosan, ZIF-8 and tung oil to obtain super-hydrophobic modified Tencel fabric, and the difference between the embodiment and example 1 is only that the concentration of the tung oil ethanol solution is different, and the embodiment specifically comprises the following steps.

[0068] Glacial acetic acid is dissolved in 50 mL of deionized water to prepare an acetic acid solution with a concentration of 2%. Then, 1.55 g of chitosan is dissolved in the obtained acetic acid solution to prepare a chitosan solution with a concentration of 3%.

[0069] The obtained chitosan solution is immersed in 0.25 g of Tencel fabric for 10 minutes, and stirring is continuously performed. Then, the Tencel fabric is taken out, and the liquid rate on the surface of the Tencel fabric is controlled to be 80% by means of a mangle.

[0070] The Tencel fabric with the chitosan solution is heat-treated in a hot press for 3 minutes, and the heat treatment temperature is 150 DEG C. Then, the heat-treated Tencel fabric is immersed into an aqueous solution of zinc acetate dihydrate with a concentration of 1.44%, and an aqueous solution of dimethylimidazole with a concentration of 17.22% is added, stirring is performed for 0.5 hours, and then standing is performed for 24 hours. After the standing treatment is completed, water washing is repeatedly performed, and drying is performed.

[0071] The dried Tencel fabric was immersed in 50 mL of the ethanol solution of tung oil with a concentration of 1%, and taken out after standing for 2 minutes. After washing and drying, the super-hydrophobic modified Tencel fabric was obtained.

[0072] Example 4

[0073] This example provides a preparation method for functionally modifying Tencel fabric by using chitosan, ZIF-8 and tung oil to obtain a super-hydrophobic modified Tencel fabric, which specifically comprises the following steps:

[0074] Glacial acetic acid was dissolved in 50 mL of deionized water to prepare an acetic acid solution with a concentration of 2%. Then, 1.55 g of chitosan was dissolved in the obtained acetic acid solution to prepare a chitosan solution with a concentration of 3%.

[0075] The 0.25 g of Tencel fabric was immersed in the obtained chitosan solution for 5 minutes with constant stirring. Then, the Tencel fabric was taken out, and the liquid retention rate on the surface of the Tencel fabric was controlled to be 80% by a mangle.

[0076] The Tencel fabric with the chitosan solution was heat-treated in a hot press for 3 minutes, and the heat treatment temperature was 160°C.

[0077] Then, the heat-treated Tencel fabric was immersed in a zinc acetate dihydrate aqueous solution with a concentration of 2%, and a dimethylimidazole aqueous solution with a concentration of 20% was added. After stirring for 0.5 hours, it was stood for 12 hours. After the standing treatment was completed, it was repeatedly washed with water and dried.

[0078] The dried Tencel fabric was immersed in 50 mL of the ethanol solution of tung oil with a concentration of 1%, and taken out after standing for 2 minutes. After washing and drying, the super-hydrophobic modified Tencel fabric was obtained.

[0079] Example 5

[0080] This example provides a preparation method for functionally modifying Tencel fabric by using chitosan, ZIF-8 and tung oil to obtain a super-hydrophobic modified Tencel fabric, which specifically comprises the following steps:

[0081] Glacial acetic acid was dissolved in 50 mL of deionized water to prepare an acetic acid solution with a concentration of 2%. Then, 1.55 g of chitosan was dissolved in the obtained acetic acid solution to prepare a chitosan solution with a concentration of 3%.

[0082] The 0.25 g of Tencel fabric was immersed in the obtained chitosan solution for 5 minutes with constant stirring. Then, the Tencel fabric was taken out, and the liquid retention rate on the surface of the Tencel fabric was controlled to be 80% by a mangle.

[0083] The Tencel fabric with the chitosan solution was heat treated in a hot press for 5 minutes at a temperature of 140°C. Subsequently, the heat treated Tencel fabric was immersed in an aqueous solution of zinc acetate dihydrate with a concentration of 1%, and an aqueous solution of dimethylimidazole with a concentration of 15% was added. After stirring for 0.5 hours, the Tencel fabric was left to stand for 24 hours. After the standing process was completed, the Tencel fabric was repeatedly washed with water and dried.

[0084] The dried Tencel fabric was immersed in 50 mL of an ethanol solution of tung oil with a concentration of 3% and left to stand for 5 minutes. After washing with water and drying, the superhydrophobic modified Tencel fabric was obtained.

[0085] Comparative Example 1

[0086] The Tencel fabric of the present comparative example was only subjected to the above-mentioned pretreatment.

[0087] Comparative Example 2

[0088] The present comparative example was different from Example 1 in that the Tencel fabric was only modified using chitosan and ZIF-8, and included the following steps.

[0089] Glycolic acid was dissolved in 50 mL of deionized water to obtain an acetic acid solution with a concentration of 2%. Subsequently, 1.55 g of chitosan was dissolved in the obtained acetic acid solution to obtain a chitosan solution with a concentration of 3%.

[0090] 0.25 g of Tencel fabric was immersed in the obtained chitosan solution for 10 minutes while being continuously stirred. Subsequently, the Tencel fabric was taken out, and the pick-up rate of the Tencel fabric surface was controlled to be 80% by a mangle.

[0091] The Tencel fabric with the chitosan solution was heat treated in a hot press for 3 minutes at a temperature of 150°C.

[0092] Subsequently, the heat treated Tencel fabric was immersed in an aqueous solution of zinc acetate dihydrate with a concentration of 1.44%, and an aqueous solution of dimethylimidazole with a concentration of 17.22% was added. After stirring for 0.5 hours, the Tencel fabric was left to stand for 24 hours. After the standing process was completed, the Tencel fabric was repeatedly washed with water and dried to obtain the modified Tencel fabric.

[0093] Test and Results

[0094] The modified Tencel fabric obtained in Example 1 was subjected to soaping treatment, and then the morphology and surface contact angle were characterized and compared with the modified Tencel fabrics obtained in Comparative Example 1 and Comparative Example 2.

[0095] The soaping treatment method is carried out according to the standard of GB / T 3921-2008 Textiles. Color fastness test. Color fastness to soaping. The concentration of the soaping solution is 5 g / L, the bath ratio is 1:50, the rotation speed is (40±2) r / min, the temperature is 40℃, and each 30 minutes is recorded as one soaping. The modified Tencel fabric prepared according to the method of Example 1 is soaped for 20 times, and the surface micro-morphology and the surface contact angle of the Tencel fabric after soaping for 5, 10, 15 and 20 times are characterized respectively. The soaping process, characterization method of Example 2 and Example 3 are the same as Example 1.

[0096] Figure 1 The surface micro-morphology of Comparative Example 1 (only pretreated Tencel fabric), Comparative Example 2 (chitosan and ZIF-8 modified Tencel fabric), and Example 1 (chitosan, ZIF-8 and tung oil modified Tencel fabric) is shown. It can be found from the figure that the surface of the Tencel fabric pretreated only is relatively smooth. After being modified by chitosan and ZIF-8, the surface of the Tencel fabric appears irregular scale-like morphology, which is caused by the in-situ growth of ZIF-8 on the chitosan film on the surface of the Tencel fabric. After being further treated by tung oil (as shown in Figure 1 c), a film is formed on the outer surface of the Tencel fabric, which completely wraps the protruding morphology. Figure 1

[0097] Figure 2 The surface contact angle of Comparative Example 1 (only pretreated Tencel fabric), Comparative Example 2 (chitosan and ZIF-8 modified Tencel fabric), and Example 1 (chitosan, ZIF-8 and tung oil modified Tencel fabric) is shown. It can be found from the figure that the contact angle of the Tencel fabric is 0°, which is caused by the existence of a large number of hydrophilic hydroxyl groups in the structure of the Tencel fabric. After being modified by chitosan and ZIF-8, the contact angle of the Tencel fabric is improved to 60.9°, which is because the introduction of chitosan and ZIF-8 improves the roughness of the surface of the Tencel fabric. After being treated by tung oil, the contact angle of the Tencel fabric reaches 146.6°, showing hydrophobic performance. This is because tung oil as a natural low surface energy material can reduce the surface tension of the Tencel fabric.

[0098] Figure 3 and Figure 4 ​The surface micro-morphology and contact angle of the modified Tencel fabric prepared according to the method of Example 1 after 5 times (a), 10 times (b), 15 times (c), 20 times (d) of soaping, respectively, are shown. During the soaping process, a large amount of tung oil acid is produced by the reaction of tung oil and alkali. These tung oil acids can induce the morphology of ZIF-8 to change, producing flaky morphology and accumulating between layers, and finally forming nano-flower-like with different morphologies. In addition, as the number of soaping increases, it can be observed that the nano-flowers produced on the surface of the Tencel fabric also increase accordingly, and the size of the nano-flowers gradually decreases. The rougher the surface of the substrate, the more conducive to obtaining super-hydrophobic properties. These gradually decreasing nano-flowers play a crucial role in improving the super-hydrophobic properties of the Tencel fabric as the number of soaping increases. As shown in Figure 4 As shown, the surface contact angle of the modified Tencel fabric gradually increases from 151.9° to 164.8° as the number of soaping increases.

[0099] Figure 5 The surface micro-morphology of the modified Tencel fabric prepared according to the method of Example 2 (a) and Example 3 (b) after 5 times of soaping is shown. Figure 5 The results show that the Tencel fabric modified by lower (1%) or higher (3%) concentration of tung oil will produce nano-flowers during the soaping process, and the surface contact angle after 5 times of soaping is greater than 150°, with super-hydrophobic properties. However, there are still some differences between the Tencel fabric modified by 2% concentration of tung oil in Example 2 and Figure 3 When using Tencel fabric modified by 1% concentration of tung oil, the size of the nano-flowers produced after 5 times of soaping is smaller. This is because there is less tung oil attached to the surface of the Tencel fabric, which has been quickly hydrolyzed into tung oil acid in fewer soaping cycles. Such results mean that these nano-flowers will face the destruction brought by soaping after fewer soaping times. When using Tencel fabric modified by 3% concentration of tung oil, the size of the nano-flowers produced after 5 times of soaping is small and few. This may be because a thick film of tung oil is produced on the surface of the Tencel fabric, which isolates most of the tung oil acid from contacting with ZIF-8. Based on the above analysis and results, 2% concentration of tung oil (i.e. Example 1) is the optimal treatment scheme.

[0100] The above results show that the Tencel fabric modified by chitosan, ZIF-8 and tung oil according to the modification method of the present application can impart hydrophobic properties to the Tencel fabric. During the soaping process, it obtains super-hydrophobic properties, and the hydrophobic properties gradually increase as the number of soaping increases.

[0101] The super-hydrophobic modified Tencel fabric of the application has improved hydrophobic performance with the increase of the number of soaping, and the preparation method comprises the following steps: (1) soaking treatment in chitosan solution; (2) heat treatment; (3) in-situ growth of zeolite imidazolate framework (ZIF-8); (4) soaking treatment in tung oil ethanol solution. The Tencel fabric treated by the above steps has excellent hydrophobic performance, and obtains super-hydrophobic performance in the soaping process, and the super-hydrophobic performance gradually increases with the increase of the number of soaping, and has wide application prospect.

[0102] The above examples are only for illustrating the technical concept and characteristics of the application, and the purpose is to enable the person skilled in the art to understand the content of the application and implement it, and cannot limit the protection scope of the application, and any equivalent changes or modifications made according to the spirit and essence of the application should be covered within the protection scope of the application.

[0103] The endpoints of the ranges and any values disclosed in this document are not limited to the precise values recited as the exact dimensions are not considered critical for the application. The ranges and values should be interpreted as being approximate such that modest variation from the stated values of the endpoints is expected. For values whose endpoints contain the value of zero, for example, being used to express the direction of the property (e.g., molecular weight, percent, etc.), either the positive or negative value of the endpoint is used as the lower limit and the positive or negative value of the other endpoint is used as the upper limit, to generate a range that includes one or both of the two endpoints. For numerical ranges that include endpoints, each intervening value will be included between the two endpoints (e.g., for numbers ranging from 1 to 10, this will include 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10).

Claims

1. A method for preparing a superhydrophobic modified viscose fabric, characterized by, The method comprises the following steps: immersing the pretreated Tencel fabric into an acetic acid solution of chitosan, and then controlling the liquid rate of the fabric surface to be 70%-90%; subjecting the Tencel fabric with the chitosan solution to heat treatment at a temperature of 140-160℃ for 1-5 minutes; immersing the heat-treated Tencel fabric into an aqueous solution of zinc acetate dihydrate for 0.1-0.5 hours, then adding an aqueous solution of dimethylimidazole, stirring and standing for reaction, taking out the Tencel fabric after the reaction, washing with water and drying; immersing the dried Tencel fabric into an ethanol solution of tung oil and standing, and then controlling the liquid rate of the fabric surface to be 40%-70%; taking out the Tencel fabric, washing and drying, and placing in air for 10-30 days to obtain the super-hydrophobic modified Tencel fabric.

2. The production method according to claim 1, characterized by, The acetic acid solution of chitosan is formed by dissolving chitosan in an acetic acid solution with a concentration of 1%-3%, and the concentration of chitosan in the acetic acid solution of chitosan is 2%-4%.

3. The preparation method according to claim 1, characterized in that, The heat treatment is heat treatment of the Tencel fabric with the chitosan solution by using a hot press or a flat plate press.

4. The method of claim 1, wherein, The concentration of the aqueous solution of zinc acetate dihydrate is 1%-2%, and the concentration of the aqueous solution of dimethylimidazole is 15%-20%.

5. The preparation method according to claim 1, characterized in that, The stirring and standing for reaction is stirring for 0.1-1 hours and then standing for 12-36 hours.

6. The method of claim 1, wherein, The concentration of tung oil in the ethanol solution of tung oil is 1%-3%, and the standing time is 2-10 minutes.

7. The preparation method according to claim 1, characterized in that, The pretreatment is: adding the Tencel fabric into a solution composed of soap flakes, sodium carbonate and deionized water, gradually heating to 65-75℃ under stirring, and keeping the temperature; after the end, taking out the Tencel fabric, repeatedly washing with deionized water, drying, and equilibrating and standing at room temperature for 10-16 hours to obtain clean Tencel fabric.

8. The method of any one of claims 1-7, wherein, The surface contact angle of the prepared super-hydrophobic modified Tencel fabric is 145°-150°.

9. A superhydrophobic modified Tencel fabric prepared by the method according to any one of claims 1 to 8, characterized in that, The hydrophobic property of the super-hydrophobic modified Tencel fabric is improved with the increase of the number of soaping.

10. The superhydrophobic modified Tencel fabric according to claim 9, wherein, The surface contact angle of the super-hydrophobic modified Tencel fabric after soaping is 150°-166°.

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