Hydrophobic fabric and preparation method thereof

Abstract

The invention relates to the technical field of new materials, and discloses a hydrophobic fabric and a preparation method thereof. The method comprises the following steps: (1) performing ultrasonic treatment and / or low-concentration alkali liquor dipping treatment on a fabric, and washing to obtain a pretreated fabric; (2) dissolving the heptadecafluorodecyl trimethoxy silane in a solvent, so as to obtain a heptadecafluorodecyl trimethoxy silane solution with the concentration of 0.1 to 10 weight percent; and (3) soaking the pretreated fabric in the heptadecafluorodecyl trimethoxysilane solution, and airing to obtain the hydrophobic fabric. According to the method provided by the invention, the excellent hydrophobic effect can be obtained by changing the chemical characteristics on the premise that the surface appearance of the fabric fiber is not obviously changed, and the fiber fabric with excellent hydrophobic performance is finally prepared.

Description

Technical Field

[0001] The present invention relates to the technical field of new materials, and particularly relates to a hydrophobic fabric and a preparation method thereof. Background Art

[0002] In the prior art, due to its natural hydrophilic characteristics, cotton fabric is widely used in the fields of clothing and home textiles. However, with the increasing demand for functional fabrics, cotton fabrics with hydrophobic properties have become a research hotspot. Currently, most methods for achieving hydrophobic properties rely on changing the surface morphology of cotton fabrics, such as introducing micro-nano structures or roughening treatments. Although these methods can effectively improve the hydrophobic properties of fabrics, they usually have problems such as cumbersome processes and high modification costs. Therefore, methods such as the impregnation method are often used to reduce the modification cost.

[0003] Currently, the mainstream strategy for developing hydrophobic fabric coating materials for impregnation is to impregnate hydrophobic finishing agents onto fiber materials through methods such as the template method, sol-gel hydrothermal method, and layer-by-layer self-assembly method. However, defects such as low adhesion, weak mechanical strength, and limited bonding ability of the hydrophobic coating limit the durable use of the hydrophobic ability. The surface of the obtained hydrophobic modified fabric is mechanically damaged, its softness and hand feel are affected, and there are still problems such as low durability of the hydrophobic ability, poor stability of the hydrophobic property, and easy loss of hydrophobicity when the fabric is mechanically damaged.

[0004] Therefore, how to achieve excellent hydrophobic properties by means of chemical modification without significantly changing the surface morphology of cotton fabrics has become the key to solving the above problems. Summary of the Invention

[0005] The object of the present invention is to overcome the problems in the prior art that the surface of the fabric is mechanically damaged after hydrophobic modification, the softness and hand feel of the fabric become poor, and the durability of the hydrophobic ability is low and the stability of the hydrophobic property is poor.

[0006] To achieve the above object, in the first aspect of the present invention, a method for preparing a hydrophobic fabric is provided, and the method includes the following steps:

[0007] (1) Ultrasonically treating and / or impregnating the fabric with a low-concentration alkali solution, and washing to obtain a pretreated fabric;

[0008] (2) Dissolving heptadecafluorodecyltrimethoxysilane in a solvent to obtain a heptadecafluorodecyltrimethoxysilane solution with a concentration of 0.1-10 wt%;

[0009] (3) Immersing the pretreated fabric in the heptadecafluorodecyltrimethoxysilane solution, and drying in air to obtain a hydrophobic fabric.

[0010] In the second aspect of the present invention, a hydrophobic fabric prepared by the method described in the first aspect is provided.

[0011] Compared with the prior art, the method provided by the present invention has at least the following beneficial effects:

[0012] (1) By pretreating the fiber fabric and combining with hydrophobic modification of heptadecafluorodecyltrimethoxysilane, the present invention effectively regulates the interaction between heptadecafluorodecyltrimethoxysilane and composite fibers, significantly improves the hydrophobic performance of the composite fibers, and realizes changing the chemical properties to obtain excellent hydrophobic effects on the premise that the surface morphology of the fabric fibers does not change significantly, and finally obtains a fiber fabric with excellent hydrophobic performance;

[0013] Moreover, the principle of the low-concentration alkali solution impregnation treatment herein is different from that of the conventional alkali solution etching, which generates sodium cellulose by alkali hydrolysis of cellulose and reduces the crystallinity of cellulose to enhance the reaction activity and adsorption; the low-concentration alkali solution impregnation treatment of the present invention only moderately modifies the fibers, avoiding the negative effects such as corrosion, excessive swelling and depolymerization of the fibers under high-concentration alkali solution treatment;

[0014] (2) The hydrolysis rate of the heptadecafluorodecyltrimethoxysilane hydrophobic agent used in the present invention is faster and the efficiency is higher than that of the commonly used fluorosilanes containing ethoxy groups. By treating the cotton-containing fabric with perfluorosilane, the fluorine element in the perfluorosilane is introduced onto the surface of the cotton fiber through a chemical reaction. Due to the extremely high electronegativity and extremely low polarizability of the fluorine element in the perfluorosilane, the hydrophobic performance of the cotton-containing fabric is effectively improved. At the same time, the C-F bond in the perfluorosilane exhibits high chemical inertness, symmetry and smoothness, which can significantly reduce the surface free energy of the cotton fiber, thereby inhibiting the wetting effect of water molecules on the surface. In addition, the perfluorosilane reacts with the hydroxyl groups (-OH) on the fiber surface through covalent bonding and hydrogen bonding to form a stable chemical shielding layer, covering the hydrophilic functional groups of the fiber and further enhancing the hydrophobicity. Moreover, the active silanol generated after hydrolysis can form chemical bonds with the hydroxyl groups on the surface of the cotton fiber fabric and the oxygen-containing groups generated by alkali solution etching, and the hydrophobicity of the formed coating is more durable;

[0015] (3) The method of the present invention is applicable to the immersion of most fabrics, such as nylon fabrics, vinylon fabrics, polyester fabrics, polypropylene fabrics, spandex fabrics, polyethylene fiber fabrics, and cotton fiber fabrics;

[0016] (4) The method of the present invention has wide sources of raw materials, simple preparation process, low cost and high efficiency, and has good industrial application prospects. Description of the Drawings

[0017] Figure 1 is a physical effect diagram of a water droplet loaded on a hydrophobic fabric prepared in a preferred embodiment of the present invention;

[0018] Figure 2It is a physical effect diagram of a hydrophobic fabric loaded with water droplets prepared in another preferred embodiment of the present invention;

[0019] Figure 3 It is a scanning electron micrograph of the hydrophobic fabric prepared in the preferred embodiment of the present invention;

[0020] Figure 4 It is a scanning electron micrograph of the hydrophobic fabric prepared in Comparative Example 2 of the present invention. Detailed implementation manners

[0021] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0022] As described above, the first aspect of the present invention provides a method for preparing a hydrophobic fabric, and the method includes the following steps:

[0023] (1) Subjecting the fabric to ultrasonic treatment and / or low-concentration alkali solution impregnation treatment, and washing to obtain a pretreated fabric;

[0024] (2) Dissolving heptadecafluorodecyltrimethoxysilane in a solvent to obtain a heptadecafluorodecyltrimethoxysilane solution with a concentration of 0.1-10 wt%;

[0025] (3) Immersing the pretreated fabric in the heptadecafluorodecyltrimethoxysilane solution, and drying to obtain a hydrophobic fabric.

[0026] Preferably, in step (1), the fabric is successively subjected to the ultrasonic treatment and the low-concentration alkali solution impregnation treatment, and washed to obtain a pretreated fabric. In this preferred case, it is more beneficial to maintain the original morphology of the fabric while improving the hydrophobic performance of the fabric.

[0027] Preferably, in step (1), the fabric is selected from at least one of a regenerated polyester fiber fabric, a polyamide fabric, a vinylon fabric, a polyester fabric, a polypropylene fabric, a spandex fabric, a polyethylene fiber fabric, and a cotton fiber fabric.

[0028] Further preferably, the method of the present invention further includes: in step (1), immersing the fabric in a beaker filled with distilled water for the ultrasonic treatment, and the conditions of the ultrasonic treatment at least satisfy: the ultrasonic power is 30-50 KHz, and the time is 5-25 min.

[0029] Preferably, in step (1), the conditions for the low-concentration alkali solution impregnation treatment at least satisfy: the alkali solution concentration is 0.1-0.3 wt%, and the time is 0.1-2 h. In this preferred case, partial modification of cellulose can be achieved, with a decrease in crystallinity and an increase in surface roughness, without causing excessive damage such as fiber depolymerization, swelling, or fracture.

[0030] According to a preferred embodiment, in step (1), the alkali solution is selected from at least one of sodium hydroxide solution, potassium hydroxide solution, and sodium carbonate solution.

[0031] Preferably, in step (1), the washing includes: rinsing the fabric after the low-concentration alkali solution impregnation treatment 3-5 times with distilled water.

[0032] Preferably, in step (2), the solvent is anhydrous ethanol.

[0033] In a preferred case, in step (2), the dissolution is carried out under stirring conditions and at least satisfies: the temperature is 20-28 °C, the rotation speed is 200-1000 rpm, and the time is 5-15 min.

[0034] Further preferably, in step (3), the soaking is carried out by standing still or stirring at a rotation speed lower than 2000 rpm for 0.1-6 h.

[0035] As described above, the second aspect of the present invention provides a hydrophobic fabric prepared by the method described in the first aspect.

[0036] The present invention is described in detail below through examples. Unless otherwise specified, the raw materials used are ordinary commercially available products.

[0037] Solvent: anhydrous ethanol;

[0038] Alkali solution: sodium hydroxide solution;

[0039] Fabric:

[0040] Fabric I: cotton fiber fabric;

[0041] Fabric II: regenerated polyester fiber fabric.

[0042] Example 1

[0043] This example is used to illustrate that the method for preparing a hydrophobic fabric provided by the present invention is carried out according to the following steps:

[0044] (1) First, immerse the fabric (Fabric I) in a beaker filled with distilled water, and then perform ultrasonic treatment for 20 min in an ultrasonic device together with the beaker. The ultrasonic power is 40 KHz to obtain the first fabric. Then, impregnate the first fabric in an alkali solution with a concentration of 0.3 wt% for 0.25 h to obtain the second fabric. Next, rinse the second fabric with distilled water three times to obtain the pretreated fabric;

[0045] (2) At 25 °C, dissolve 1H,1H,2H,2H - perfluorodecyltrimethoxysilane in a solvent under stirring conditions at a rotation speed of 600 rpm for 10 min to obtain a 1H,1H,2H,2H - perfluorodecyltrimethoxysilane solution with a concentration of 4 wt%;

[0046] (3) Stir the pretreated fabric in the 1H,1H,2H,2H - perfluorodecyltrimethoxysilane solution at a rotation speed of 300 rpm for 0.5 h for soaking, and after air - drying, obtain a hydrophobic fabric named P1;

[0047] Figure 1 The physical effect picture of P1 loaded with water droplets is shown.

[0048] Example 2

[0049] This example is used to illustrate that the method for preparing a hydrophobic fabric provided by the present invention is carried out according to the following steps:

[0050] (1) First, immerse the fabric (Fabric II) in a beaker filled with distilled water, and then perform ultrasonic treatment for 20 min in an ultrasonic device together with the beaker. The ultrasonic power is 40 KHz to obtain the first fabric. Then, impregnate the first fabric in an alkali solution with a concentration of 0.1 wt% for 0.25 h to obtain the second fabric. Next, rinse the second fabric with distilled water three times to obtain the pretreated fabric;

[0051] (2) At 25 °C, dissolve 1H,1H,2H,2H - perfluorodecyltrimethoxysilane in a solvent under stirring conditions at a rotation speed of 800 rpm for 10 min to obtain a 1H,1H,2H,2H - perfluorodecyltrimethoxysilane solution with a concentration of 6 wt%;

[0052] (3) Stir the pretreated fabric in the 1H,1H,2H,2H - perfluorodecyltrimethoxysilane solution at a rotation speed of 500 rpm for 1 h for soaking, and after air - drying, obtain a hydrophobic fabric named P2;

[0053] Figure 2 The physical effect picture of P2 loaded with water droplets is shown.

[0054] Example 3

[0055] This example is carried out in a similar way to Example 1. The difference is that in step (1), the low-concentration alkali solution impregnation treatment is not carried out, and only ultrasonic treatment is performed on the fabric to obtain the pretreated fabric;

[0056] Finally, a hydrophobic fabric is obtained and named P3.

[0057] Example 4

[0058] This example is carried out in a similar way to Example 1. The difference is that in step (1), ultrasonic treatment is not carried out, and only low-concentration alkali solution impregnation treatment is performed on the fabric, and the pretreated fabric is obtained after washing;

[0059] Finally, a hydrophobic fabric is obtained and named P4.

[0060] Comparative Example 1

[0061] This comparative example is carried out in a similar way to Example 1. The difference is that instead of performing the operation in step (1), the fabric is directly soaked, specifically including:

[0062] S1. At 25°C, under the stirring condition of a rotation speed of 600 rpm, dissolve 1H,1H,2H,2H-perfluorodecyltrimethoxysilane in a solvent for 10 min to obtain a 1H,1H,2H,2H-perfluorodecyltrimethoxysilane solution with a concentration of 4 wt%;

[0063] S2. Then stir the fabric in the 1H,1H,2H,2H-perfluorodecyltrimethoxysilane solution at a rotation speed of 300 rpm for 0.5 h for soaking, and obtain the hydrophobic fabric after air drying;

[0064] Finally, a hydrophobic fabric is obtained and named DP1.

[0065] Comparative Example 2

[0066] This comparative example is carried out in a similar way to Example 1. The difference is that in step (1), the alkali solution concentration in the alkali solution impregnation treatment is 10 wt%;

[0067] Finally, a hydrophobic fabric is obtained and named DP2.

[0068] Comparative Example 3

[0069] This comparative example is carried out in a similar way to Example 1. The difference is that in step (1), ultrasonic treatment is not carried out, and only alkali solution impregnation treatment is performed on the fabric, and the alkali solution concentration in the alkali solution impregnation treatment is 10 wt%;

[0070] Finally, a hydrophobic fabric is obtained and named DP3.

[0071] Comparative Example 4

[0072] This comparative example was carried out in a similar manner to Example 1, except that in step (2), an equal mass of tridecafluorooctyltriethoxysilane was used instead of heptadecafluorodecyltrimethoxysilane for dissolution;

[0073] Finally, a hydrophobic fabric was obtained and named DP4.

[0074] Comparative Example 5

[0075] This comparative example was carried out in a similar manner to Example 1, except that in step (2), an equal mass of heptadecafluorodecyltriethoxysilane was used instead of heptadecafluorodecyltrimethoxysilane for dissolution;

[0076] Finally, a hydrophobic fabric was obtained and named DP5.

[0077] Test Example 1

[0078] This test example carried out the following tests on the hydrophobic fabrics prepared in the above examples:

[0079] Characterization of the microscopic morphology using a scanning electron microscope, where, Figure 3 shows the electron micrograph of the hydrophobic fabric P1; Figure 4 shows the electron micrograph of the hydrophobic fabric DP2 prepared in Comparative Example 2; It can be seen from Figure 3 and Figure 4 that when the concentration of the lye is too high, it will cause obvious damage to the fabric surface.

[0080] Measuring the tensile strength using a universal testing machine;

[0081] Measuring the water contact angle using a water contact angle instrument;

[0082] The results of the tensile strength and water contact angle are shown in Table 1.

[0083] Table 1

[0084] Item P1 P2 P3 P4 DP1 DP2 DP3 DP4 DP5 Tensile strength (MPa) 18.2 18.2 18.3 18.2 18.3 12.0 12.8 18.2 18.3 Water contact angle (°) 145 141 131 128 95 125 112 93 0

[0085] From the above results, it can be seen that the method provided by the present invention achieves excellent hydrophobic effects by changing chemical properties on the premise that the surface morphology of the fabric fibers does not change significantly, and finally prepares a fiber fabric with excellent hydrophobic performance. Moreover, the preparation process is simple, low-cost, and high-efficiency, and has good industrial application prospects.

[0086] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for preparing a hydrophobic fabric, characterized in that: The method comprises the following steps: (1) subjecting the fabric to ultrasonic treatment and / or low-concentration alkali solution immersion treatment, and washing to obtain a pretreated fabric; (2) dissolving heptadecafluorodecyltrimethoxysilane in a solvent to obtain a heptadecafluorodecyltrimethoxysilane solution having a concentration of 0.1-10 wt %; (3) Soaking the pretreated fabric in the heptadecafluorodecyltrimethoxysilane solution and drying the pretreated fabric to obtain a hydrophobic fabric.

2. The method according to claim 1, characterized in that: In step (1), the fabric is subjected to the ultrasonic treatment and the low-concentration alkali solution immersion treatment in sequence, and the pretreated fabric is obtained after washing.

3. The method according to claim 1 or 2, characterized in that: The method further comprises: in step (1), immersing the fabric in a beaker filled with distilled water for ultrasonic treatment, and the conditions of the ultrasonic treatment at least meet the following conditions: ultrasonic power is 30-50KHz, and the time is 5-25min.

4. The method according to claim 1 or 2, characterized in that: In step (1), the conditions for the low-concentration alkali solution immersion treatment at least meet the following requirements: the alkali solution concentration is 0.1-0.3wt% and the time is 0.1-2h.

5. The method according to claim 1 or 2, characterized in that: In step (1), the alkali solution is selected from at least one of a sodium hydroxide solution, a potassium hydroxide solution and a sodium carbonate solution.

6. The method according to claim 1 or 2, characterized in that: In step (2), the dissolution is carried out under stirring conditions and at least meets the following conditions: temperature of 20-28° C., rotation speed of 200-1000 rpm, and time of 5-15 min.

7. The method according to claim 1 or 2, characterized in that: In step (3), the soaking is carried out by standing or stirring at a rotation speed lower than 2000 rpm for 0.1-6 hours.

8. A hydrophobic fabric prepared by the method according to any one of claims 1 to 7.

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