A modified cotton fabric, its preparation method and use

Abstract

The application discloses modified cotton fabric and a preparation method and application thereof, and relates to the field of textile fabrics.In the preparation of the modified cotton fabric, chitosan is pretreated by 2-bromoisobutyryl bromide, then acrylic acid and methyl acrylate are grafted and polymerized by an atom transfer radical polymerization method to obtain pre-modified chitosan, then the pre-modified chitosan is sequentially reacted with oxalyl chloride and 4-hydroxybenzotriazole to prepare modified chitosan; cotton fabric is ultrasonically pretreated by a sodium dodecyl sulfate solution, then sequentially reacts with 6-chlorohexanoyl chloride and N,N-dimethylallylamine to prepare pre-modified cotton fabric, and finally, the pre-modified cotton fabric is reacted with a modified liquid prepared from modified chitosan, dimethyl phosphite and 1,4-butanediol to prepare the modified cotton fabric.The modified cotton fabric prepared by the application has excellent ultraviolet resistance, antibacterial property, wrinkle resistance and flame retardance.

Description

Technical Field

[0001] This invention relates to the field of textile fabrics, specifically to a modified cotton fabric, its preparation method, and its application. Background Technology

[0002] Cotton fabrics are products woven from cotton fibers. Due to their softness, comfort, breathability, warmth, and low price, cotton fabrics are the most widely used natural fabrics. Cotton fabrics have played an important role in the development of human civilization and are necessities in people's lives.

[0003] However, the application of cotton fabrics in real life still faces many problems. For example, cotton fabrics are flammable, and flames spread rapidly on them, leading to fires. Furthermore, cotton fabrics have a large surface area and a certain water retention capacity, easily providing an environment for microbial growth, which can have adverse effects on human health. Also, cotton fabrics are prone to wrinkling after wearing or washing. Therefore, modifying cotton fabrics to overcome these problems is of significant practical importance. Summary of the Invention

[0004] The purpose of this invention is to provide a modified cotton fabric, its preparation method, and its application, in order to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A modified cotton fabric, wherein the modified cotton fabric is obtained by reacting a pre-modified cotton fabric with a modifying liquid.

[0007] As an optimization, the pre-modified cotton fabric is prepared by ultrasonic pretreatment of the cotton fabric with a 1% sodium dodecyl sulfate solution, followed by reaction with 6-chlorohexanoyl chloride and N,N-dimethylallylamine in sequence.

[0008] As an optimization, the modified liquid is prepared by mixing modified chitosan, dimethyl phosphite and 1,4-butanediol.

[0009] As an optimization, the modified chitosan is prepared by reacting pre-modified chitosan with oxalyl chloride and 4-hydroxybenzotriazole in sequence.

[0010] As an optimization, the pre-modified chitosan is prepared by pretreating chitosan with 2-bromoisobutyryl bromide and then grafting acrylic acid and methyl acrylate onto the chitosan via atom transfer radical polymerization.

[0011] A method for preparing a modified cotton fabric includes the following preparation steps:

[0012] (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide are mixed evenly in a mass ratio of 2-3:15-25:1:1 and reacted at room temperature at 200-300 r / min for 1-2 h. Pure water of the same mass as the triethylamine is added, and the mixture is evaporated at 70-80 °C for 1-2 h. After filtration, the mixture is dried at 0.1-0.2 MPa and 70-80 °C for 10-14 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate are mixed evenly in a mass ratio of 1:0.3-0.4:100-120:5-6:5-6 under nitrogen protection and reacted at 90-100 °C and 200-300 r / min for 24 hours. After 26 hours, the mixture was filtered and washed 3-5 times with anhydrous ethanol. It was then dried at 0.1-0.2 MPa and 0-5°C for 20-24 hours to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxaloyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 5-7:1:5-7:25-35 and reacted at 200-300 r / min for 8-10 hours at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:3-4:5-6:10-15 and reacted at 0-5°C for 8-10 hours. The mixture was filtered, washed 3-5 times with anhydrous ethanol, and dried at 70-80°C for 10-14 hours to obtain modified chitosan.

[0013] (2) The cotton fabric is immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1-2 hours to remove impurities. Then it is immersed in pure water and sonicated for 30-50 minutes, followed by immersion in anhydrous ethanol and sonicated for 30-50 minutes. It is then washed with pure water 3-5 times and finally dried at 70-80°C for 8-10 hours to obtain the pretreated cotton fabric. The pretreated cotton fabric is then immersed in a chlorination finishing solution and reacted at 0-5°C for 6-8 hours. Then it is passed through a rolling mill with a pressure of 1.6-1.8 MPa and left to stand at 100-120°C for 20-30 minutes. Then, let it stand at 140-160℃ for 4-6 minutes, let it cool naturally to room temperature, wash it with pure water 3-5 times, and then dry it at 90℃ for 1-2 hours to obtain chlorinated cotton fabric; immerse the chlorinated cotton fabric in the pre-modified finishing solution and react it at room temperature for 6-8 hours, then pass it through a rolling mill with a pressure of 1.6-1.8MPa, let the fabric stand at 100-120℃ for 20-30 minutes, then stand at 140-160℃ for 4-6 minutes, let it cool naturally to room temperature, wash it with pure water 3-5 times, and then dry it at 90℃ for 1-2 hours to obtain pre-modified cotton fabric;

[0014] (3) Dimethyl phosphite, modified chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide are mixed evenly at room temperature in a mass ratio of 2-3:8-10:1:0.05-0.07:20-30 to prepare a modified finishing solution; the pre-modified cotton fabric is immersed in the modified finishing solution and reacted at 70-80℃ for 4-6 hours, then passed through a rolling mill with a pressure of 1.6-1.8MPa, and the fabric is left to stand at 100-120℃ for 20-30 minutes, then left to stand at 140-160℃ for 4-6 minutes, naturally cooled to room temperature, washed with pure water 3-5 times, and then dried at 90℃ for 1-2 hours to obtain the modified cotton fabric.

[0015] As an optimization, the chitosan in step (1) is of type C105801.

[0016] As an optimization, the chlorination finishing solution in step (2) is prepared by uniformly mixing 6-chlorohexanoyl chloride, triethylamine, and tetrahydrofuran at a mass ratio of 1:1:15-25; the pre-modified finishing solution is prepared by uniformly mixing N,N-dimethylallylamine and n-propanol at a mass ratio of 1:10-20; and the weight of the cotton fabric is 150 g / m². 2 .

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] In preparing modified cotton fabrics, the present invention first pretreats chitosan with 2-bromoisobutyryl bromide, then grafts acrylic acid and methyl acrylate onto the fabric using atom transfer radical polymerization to obtain pre-modified chitosan. The pre-modified chitosan is then reacted sequentially with oxalyl chloride and 4-hydroxybenzotriazole to obtain modified chitosan. The cotton fabric is then ultrasonically pretreated with sodium dodecyl sulfate solution, and subsequently reacted sequentially with 6-chlorohexanoyl chloride and N,N-dimethylallylamine to obtain pre-modified cotton fabric. Finally, the pre-modified cotton fabric is reacted with a modifying solution prepared from modified chitosan, dimethyl phosphite, and 1,4-butanediol to obtain modified cotton fabric.

[0019] First, cotton fabric is ultrasonically pretreated with sodium dodecyl sulfate solution, and then reacted sequentially with 6-chlorohexanoyl chloride and N,N-dimethylallylamine to obtain pre-modified cotton fabric, thereby forming a quaternary ammonium salt structure on the surface of the cotton fabric and improving its antibacterial properties. Second, the pre-modified cotton fabric is impregnated in a modification solution prepared from modified chitosan, dimethyl phosphite, and 1,4-butanediol. On the one hand, dimethyl phosphite can graft itself onto the cotton fabric through phosphohydroaddition, improving the flame retardant properties of the cotton fabric. On the other hand, it can also undergo transesterification with butanediol, causing cross-linking between the fibers of the cotton fabric, restraining and hindering the mutual movement and slippage of cellulose molecular chain segments, maintaining the morphological stability of the fibers, and thus improving the wrinkle resistance of the cotton fabric.

[0020] In addition, due to the previous treatment of chitosan, 4-hydroxybenzotriazole and methyl acrylate were grafted onto the chitosan. The benzotriazole structure can effectively absorb ultraviolet light, thereby improving the UV resistance of cotton fabrics. The structure of methyl acrylate can participate in the transesterification reaction of dimethyl phosphate, thus firmly grafting the modified chitosan onto the cotton fabric and ensuring the durability of the UV resistance. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1

[0023] A method for preparing a modified cotton fabric, the method comprising the following preparation steps:

[0024] (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide were mixed evenly in a mass ratio of 2:15:1:1 and reacted at 200 r / min for 2 h at room temperature. Pure water of the same mass as the triethylamine was added, and the mixture was evaporated at 70 °C for 2 h. After filtration, the mixture was dried at 0.1 MPa and 70 °C for 14 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate were mixed evenly in a mass ratio of 1:0.3:100:5:5 under nitrogen protection and reacted at 90 °C and 200 r / min for 26 h. The mixture was filtered, washed three times with anhydrous ethanol, and dried at 0.1 MPa and 0 °C for 24 h to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxaloyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 5:1:5:25 and reacted at 200 r / min for 8 h at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:3:5:10 and reacted at 0 °C for 10 h. The mixture was filtered, washed three times with anhydrous ethanol, and dried at 70 °C for 14 h to obtain modified chitosan.

[0025] (2) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 2 hours to remove impurities. Then it was immersed in pure water and sonicated for 50 minutes, then immersed in anhydrous ethanol and sonicated for 50 minutes. It was washed three times with pure water and finally dried at 70°C for 10 hours to obtain the pretreated cotton fabric. The pretreated cotton fabric was immersed in a chlorination finishing solution and reacted at 0°C for 8 hours. Then it was passed through a 1.6MPa pressure rolling mill and placed at 100°C for 30 minutes, then at 140°C for 6 minutes. It was then naturally cooled to room temperature, washed three times with pure water, and then dried at 90°C for 2 hours to obtain the chlorinated cotton fabric. The chlorinated cotton fabric was immersed in a premodified finishing solution and reacted at room temperature for 8 hours. Then it was passed through a 1.6MPa pressure rolling mill and placed at 100°C for 30 minutes, then at 140°C for 6 minutes. It was then naturally cooled to room temperature, washed three times with pure water, and then dried at 90°C for 2 hours to obtain the premodified cotton fabric.

[0026] (3) Dimethyl phosphite, modified chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 2:8:1:0.05:20 to prepare a modified finishing solution; the pre-modified cotton fabric was immersed in the modified finishing solution and reacted at 70°C for 6 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.6 MPa, and then left to stand at 100°C for 30 minutes, and then left to stand at 140°C for 6 minutes. The fabric was then naturally cooled to room temperature, washed three times with pure water, and then dried at 90°C for 2 hours to obtain the modified cotton fabric.

[0027] Example 2

[0028] A method for preparing a modified cotton fabric, the method comprising the following preparation steps:

[0029] (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide were mixed evenly in a mass ratio of 2.5:20:1:1 and reacted at 250 r / min for 1.5 h at room temperature. Pure water of the same mass as the triethylamine was added, and the mixture was evaporated at 75 °C for 1.5 h. After filtration, the mixture was dried at 0.15 MPa and 75 °C for 12 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate were mixed evenly in a mass ratio of 1:0.35:110:5.5:5.5 under nitrogen protection and reacted at 95 °C and 250 r / min for 2 h. After 5 hours of filtration, the mixture was washed four times with anhydrous ethanol and dried at 0.15 MPa and 2.5 °C for 22 hours to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxalyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 6:1:6:30 and reacted at 250 r / min for 9 hours at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:3.5:5.5:12.5 and reacted at 2.5 °C for 9 hours. After filtration, the mixture was washed four times with anhydrous ethanol and dried at 75 °C for 12 hours to obtain modified chitosan.

[0030] (2) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1.5 h to remove impurities. It was then immersed in pure water and sonicated for 40 min, followed by immersion in anhydrous ethanol and sonication for 40 min. The fabric was washed four times with pure water and finally dried at 75°C for 9 h to obtain the pretreated cotton fabric. The pretreated cotton fabric was then immersed in a chlorination finishing solution and reacted at 2.5°C for 7 h. Finally, it was passed through a 1.7 MPa pressure rolling mill and allowed to stand at 110°C for 25 min. n, then let stand at 150℃ for 5 minutes, let cool naturally to room temperature, wash with pure water 4 times, and then dry at 90℃ for 1.5 hours to obtain chlorinated cotton fabric; immerse the chlorinated cotton fabric in the pre-modified finishing solution, react at room temperature for 7 hours, then pass it through a 1.7MPa pressure rolling mill, let the fabric stand at 110℃ for 25 minutes, then stand at 150℃ for 5 minutes, let cool naturally to room temperature, wash with pure water 4 times, and then dry at 90℃ for 1.5 hours to obtain pre-modified cotton fabric;

[0031] (3) Dimethyl phosphite, modified chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 2.5:9:1:0.06:25 to prepare a modified finishing solution; the pre-modified cotton fabric was immersed in the modified finishing solution and reacted at 75°C for 5 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.7 MPa, and then left to stand at 110°C for 25 minutes, and then left to stand at 150°C for 5 minutes. The fabric was then naturally cooled to room temperature, washed 4 times with pure water, and then dried at 90°C for 1.5 hours to obtain the modified cotton fabric.

[0032] Example 3

[0033] A method for preparing a modified cotton fabric, the method comprising the following preparation steps:

[0034] (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide were mixed evenly in a mass ratio of 3:25:1:1 and reacted at 300 r / min for 1 h at room temperature. Pure water of the same mass as the triethylamine was added, and the mixture was evaporated at 80 °C for 1 h. After filtration, the mixture was dried at 0.2 MPa and 80 °C for 10 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate were mixed evenly in a mass ratio of 1:0.4:120:6:6 under nitrogen protection and reacted at 100 °C and 300 r / min for 2 h. After 4 hours of filtration, the mixture was washed five times with anhydrous ethanol and dried at 0.2 MPa and 5°C for 20 hours to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxalyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 7:1:7:35 and reacted at 300 r / min for 8 hours at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:4:6:15 and reacted at 5°C for 8 hours. The mixture was then filtered, washed five times with anhydrous ethanol, and dried at 80°C for 10 hours to obtain modified chitosan.

[0035] (2) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1 hour to remove impurities. Then it was immersed in pure water and sonicated for 30 minutes. Then it was immersed in anhydrous ethanol and sonicated for 30 minutes. It was washed with pure water 5 times and finally dried at 80°C for 8 hours to obtain the pretreated cotton fabric. The pretreated cotton fabric was immersed in a chlorination finishing solution and reacted at 5°C for 6 hours. Then it was passed through a 1.8MPa pressure rolling mill and placed at 120°C for 20 minutes. Then it was placed at 160°C for 4 minutes. It was naturally cooled to room temperature and washed with pure water 5 times. Then it was dried at 90°C for 1 hour to obtain the chlorinated cotton fabric. The chlorinated cotton fabric was immersed in a premodified finishing solution and reacted at room temperature for 6 hours. Then it was passed through a 1.8MPa pressure rolling mill and placed at 120°C for 20 minutes. Then it was placed at 160°C for 4 minutes. It was naturally cooled to room temperature and washed with pure water 5 times. Then it was dried at 90°C for 1 hour to obtain the premodified cotton fabric.

[0036] (3) Dimethyl phosphite, modified chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 3:10:1:0.07:30 to prepare a modified finishing solution; the pre-modified cotton fabric was immersed in the modified finishing solution and reacted at 80°C for 4 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.8 MPa, and then left to stand at 120°C for 20 minutes, and then left to stand at 160°C for 4 minutes. The fabric was then naturally cooled to room temperature, washed 5 times with pure water, and then dried at 90°C for 1 hour to obtain the modified cotton fabric.

[0037] Comparative Example 1

[0038] A method for preparing a modified cotton fabric, the method comprising the following preparation steps:

[0039] (1) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1.5 h to remove impurities. Then it was immersed in pure water and sonicated for 40 min, then immersed in anhydrous ethanol and sonicated for 40 min. It was washed with pure water 4 times and finally dried at 75°C for 9 h to obtain the pretreated cotton fabric. The pretreated cotton fabric was immersed in a chlorination finishing solution and reacted at 2.5°C for 7 h. Then it was passed through a rolling mill with a pressure of 1.7 MPa and left to stand at 110°C for 25 min. n, then let stand at 150℃ for 5 minutes, let cool naturally to room temperature, wash with pure water 4 times, and then dry at 90℃ for 1.5 hours to obtain chlorinated cotton fabric; immerse the chlorinated cotton fabric in the pre-modified finishing solution, react at room temperature for 7 hours, then pass it through a 1.7MPa pressure rolling mill, let the fabric stand at 110℃ for 25 minutes, then stand at 150℃ for 5 minutes, let cool naturally to room temperature, wash with pure water 4 times, and then dry at 90℃ for 1.5 hours to obtain pre-modified cotton fabric;

[0040] (2) Dimethyl phosphite, chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 2.5:9:1:0.06:25 to prepare a modified finishing solution. The pre-modified cotton fabric was immersed in the modified finishing solution and reacted at 75°C for 5 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.7 MPa, and then left to stand at 110°C for 25 minutes, and then left to stand at 150°C for 5 minutes. The fabric was then naturally cooled to room temperature, washed 4 times with pure water, and then dried at 90°C for 1.5 hours to obtain the modified cotton fabric.

[0041] Comparative Example 2

[0042] (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide were mixed evenly in a mass ratio of 2.5:20:1:1 and reacted at 250 r / min for 1.5 h at room temperature. Pure water of the same mass as the triethylamine was added, and the mixture was evaporated at 75 °C for 1.5 h. After filtration, the mixture was dried at 0.15 MPa and 75 °C for 12 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate were mixed evenly in a mass ratio of 1:0.35:110:5.5:5.5 under nitrogen protection and reacted at 95 °C and 250 r / min for 2 h. After 5 hours of filtration, the mixture was washed four times with anhydrous ethanol and dried at 0.15 MPa and 2.5 °C for 22 hours to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxalyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 6:1:6:30 and reacted at 250 r / min for 9 hours at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:3.5:5.5:12.5 and reacted at 2.5 °C for 9 hours. After filtration, the mixture was washed four times with anhydrous ethanol and dried at 75 °C for 12 hours to obtain modified chitosan.

[0043] (2) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1.5 h to remove impurities. Then it was immersed in pure water and sonicated for 40 min. Then it was immersed in anhydrous ethanol and sonicated for 40 min. It was washed with pure water 4 times and finally dried at 75°C for 9 h to obtain the pretreated cotton fabric.

[0044] (3) Dimethyl phosphite, modified chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 2.5:9:1:0.06:25 to prepare a modified finishing solution; the pretreated cotton fabric was immersed in the modified finishing solution and reacted at 75°C for 5 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.7 MPa, and then left to stand at 110°C for 25 minutes, and then left to stand at 150°C for 5 minutes. The fabric was then naturally cooled to room temperature, washed 4 times with pure water, and then dried at 90°C for 1.5 hours to obtain the modified cotton fabric.

[0045] Comparative Example 3

[0046] A method for preparing a modified cotton fabric, the method comprising the following preparation steps:

[0047] (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide were mixed evenly in a mass ratio of 2.5:20:1:1 and reacted at 250 r / min for 1.5 h at room temperature. Pure water of the same mass as the triethylamine was added, and the mixture was evaporated at 75 °C for 1.5 h. After filtration, the mixture was dried at 0.15 MPa and 75 °C for 12 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate were mixed evenly in a mass ratio of 1:0.35:110:5.5:5.5 under nitrogen protection and reacted at 95 °C and 250 r / min for 2 h. After 5 hours of filtration, the mixture was washed four times with anhydrous ethanol and dried at 0.15 MPa and 2.5 °C for 22 hours to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxalyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 6:1:6:30 and reacted at 250 r / min for 9 hours at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:3.5:5.5:12.5 and reacted at 2.5 °C for 9 hours. After filtration, the mixture was washed four times with anhydrous ethanol and dried at 75 °C for 12 hours to obtain modified chitosan.

[0048] (2) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1.5 h to remove impurities. It was then immersed in pure water and sonicated for 40 min, followed by immersion in anhydrous ethanol and sonication for 40 min. The fabric was washed four times with pure water and finally dried at 75°C for 9 h to obtain the pretreated cotton fabric. The pretreated cotton fabric was then immersed in a chlorination finishing solution and reacted at 2.5°C for 7 h. Finally, it was passed through a 1.7 MPa pressure rolling mill and allowed to stand at 110°C for 25 min. n, then let stand at 150℃ for 5 minutes, let cool naturally to room temperature, wash with pure water 4 times, and then dry at 90℃ for 1.5 hours to obtain chlorinated cotton fabric; immerse the chlorinated cotton fabric in the pre-modified finishing solution, react at room temperature for 7 hours, then pass it through a 1.7MPa pressure rolling mill, let the fabric stand at 110℃ for 25 minutes, then stand at 150℃ for 5 minutes, let cool naturally to room temperature, wash with pure water 4 times, and then dry at 90℃ for 1.5 hours to obtain pre-modified cotton fabric;

[0049] (3) The modified chitosan, 1,4-butanediol and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 9:1:25 to prepare a modified finishing solution; the pre-modified cotton fabric was immersed in the modified finishing solution and reacted at 75°C for 5 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.7 MPa, and then left to stand at 110°C for 25 minutes, and then left to stand at 150°C for 5 minutes. The fabric was then naturally cooled to room temperature, washed 4 times with pure water, and then dried at 90°C for 1.5 hours to obtain the modified cotton fabric.

[0050] Comparative Example 4

[0051] A method for preparing a modified cotton fabric, the method comprising the following preparation steps:

[0052] (1) The cotton fabric was immersed in a 1% sodium dodecyl sulfate solution and sonicated for 1.5 h to remove impurities. Then it was immersed in pure water and sonicated for 40 min. Then it was immersed in anhydrous ethanol and sonicated for 40 min. It was washed with pure water 4 times and finally dried at 75°C for 9 h to obtain the pretreated cotton fabric.

[0053] (2) Chitosan, 1,4-butanediol and N,N-dimethylformamide were mixed evenly at room temperature in a mass ratio of 9:1:25 to prepare a modified finishing solution. The pretreated cotton fabric was immersed in the modified finishing solution and reacted at 75°C for 5 hours. Then, the fabric was subjected to a rolling mill with a pressure of 1.7 MPa and kept at 110°C for 25 minutes, then at 150°C for 5 minutes. It was then naturally cooled to room temperature, washed 4 times with pure water, and dried at 90°C for 1.5 hours to obtain the modified cotton fabric.

[0054] Test Example 1

[0055] Flame retardant performance testing

[0056] Test method: The test shall be conducted in accordance with GB / T5454-1997 standard, with the cotton fabric cut to 150×58mm. 2 The results are shown in Table 1.

[0057] Table 1

[0058] sample Limiting oxygen index (vol%) Example 1 34.8 Example 2 35.2 Example 3 34.6 Comparative Example 1 32.2 Comparative Example 2 26.8 Comparative Example 3 17.6 Comparative Example 4 16.9

[0059] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 1 reveals that the modified cotton fabric prepared by this invention has good flame retardant properties.

[0060] By comparison, the limiting oxygen index of Examples 1, 2, and 3 was not significantly different from that of Comparative Example 1, indicating that after pre-modification treatment of the cotton fabric and then immersing the pre-modified cotton fabric in the modifying finishing solution, the cotton fabric can react with dimethyl phosphite, thereby fixing this flame retardant component onto the cotton fabric and improving its flame retardant performance. Compared with Comparative Example 2, Examples 1, 2, and 3 showed a certain degree of decrease in the limiting oxygen index. This is because, without modification of the cotton fabric, although dimethyl phosphite in the modifying finishing solution still undergoes transesterification with the hydroxyl groups of the cotton fibers, the reduced reactivity leads to a decrease in the grafting rate of the flame retardant component and a decline in flame retardant performance. Compared with Comparative Example 3, Examples 1, 2, and 3 showed a significant decrease in the limiting oxygen index. This is because dimethyl phosphite, a flame retardant component, was not added to the modifying finishing solution in Comparative Example 3, so the flame retardant performance of the cotton fabric could not be improved, resulting in a significant reduction in flame retardant performance compared to the examples, similar to ordinary cotton fabric.

[0061] Test Example 2

[0062] Antibacterial performance test

[0063] Test method: The test was conducted according to GB / T 20944.3-2008. Cotton fabric samples were cut into 1cm diameter discs and sterilized by irradiation under a UV lamp for 30 minutes. The discs were then moistened with phosphate buffer solution and laid flat and tightly on a surface uniformly coated with a solution of *E. coli* or *Staphylococcus aureus* (approximately 10 μL). 5 The antibacterial rate was calculated by plate counting method after incubation at 37°C for 24 h on agar plates containing CFU / mL. The results are shown in Table 2.

[0064] Table 2

[0065] sample Escherichia coli antibacterial rate / % Staphylococcus aureus antibacterial rate / % Example 1 99.6 99.1 Example 2 99.7 99.3 Example 3 99.6 99.3 Comparative Example 1 98.1 97.2 Comparative Example 2 43.2 34.2 Comparative Example 3 96.3 94.6 Comparative Example 4 42.6 34.8

[0066] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 2 reveals that the modified cotton fabric prepared by this invention has good antibacterial properties.

[0067] By comparison, Examples 1, 2, and 3 showed better antibacterial performance than Comparative Example 2. This is because the cotton fabrics in Examples 1, 2, and 3 were pre-modified, and the reaction of chlorohexyl and N,N-dimethylallylamine formed a long carbon chain structure of quaternary ammonium salt. This structure has good antibacterial properties. Examples 1, 2, and 3 showed better antibacterial performance than Comparative Example 3 because, while forming the quaternary ammonium salt, the examples also grafted chitosan, a structure with antibacterial properties. In contrast, Comparative Example 3 lacked dimethyl phosphite, so it could not fix the chitosan structure onto the cotton fabric, and therefore its antibacterial performance was slightly inferior.

[0068] Test Example 3

[0069] Anti-wrinkle performance test

[0070] Test method: Cotton fabrics were tested according to GB / T 3819-1997. The results are shown in Table 3.

[0071] Table 3

[0072] sample Wrinkle recovery angle / ° Example 1 261±2.7 Example 2 263±1.2 Example 3 259±3.1 Comparative Example 1 246±1.9 Comparative Example 2 206±3.3 Comparative Example 3 158±2.9 Comparative Example 4 118±2.7

[0073] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 3 reveals that the modified cotton fabric prepared by this invention has good wrinkle resistance.

[0074] By comparison, the wrinkle recovery angles of Examples 1, 2, and 3 were all above 250°, exhibiting good wrinkle resistance. However, the wrinkle recovery angle of Comparative Example 2 showed a significant decrease. This was because the cotton fabric was not pretreated. The transesterification reaction between dimethyl phosphite and the hydroxyl groups on cellulose in the modified finishing solution caused cross-linking of the fibers. However, due to insufficient cross-linking efficiency, the degree of cross-linking of the cotton fibers was small, resulting in a certain degree of relative sliding between the fibers and a decrease in wrinkle resistance. In Comparative Example 3, no dimethyl phosphite was added as a cross-linking agent, making it difficult for the cotton fibers to cross-link. The cotton fabric was prone to deformation under stress, causing relative slippage between molecular chains. If the hydrogen bond breaking and rebuilding process was severe during stretching, a large number of newly formed hydrogen bonds hindered the recovery of macromolecular chain segments to their initial state, resulting in poor wrinkle resistance.

[0075] Test Example 4

[0076] UV protection performance test

[0077] Test method: Cotton fabrics were tested according to GB / T 18830-2009 standard. The results are shown in Table 4.

[0078] Table 4

[0079] sample UPF Example 1 112±2.2 Example 2 113±1.7 Example 3 113±1.8 Comparative Example 1 45±3.2 Comparative Example 2 82.3±1.1 Comparative Example 3 32±1.8 Comparative Example 4 28±0.9

[0080] A comparison of the experimental data from Examples 1-3 and Comparative Examples 1-4 in Table 4 reveals that the modified cotton fabric prepared by this invention has good UV resistance.

[0081] By comparison, Examples 1, 2, and 3 showed better UV resistance than Comparative Example 1. This is because Comparative Example 1 did not modify chitosan, and chitosan lacks the benzotriazole structure that absorbs ultraviolet light, resulting in a lower UPF value. Comparative Example 2, on the other hand, lacked sufficient active sites due to the absence of pre-modification of the cotton fabric, leading to a lower grafting rate of modified chitosan and thus a lower UPF value. Comparative Example 3, lacking a crosslinking agent, made it difficult for the cotton fabric and modified chitosan to crosslink, thus preventing the grafting of modified chitosan onto the cotton fabric, resulting in a lower UPF value.

[0082] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A modified cotton fabric, characterized in that, The modified cotton fabric is prepared by reacting pre-modified cotton fabric with a modifying liquid; the pre-modified cotton fabric is prepared by ultrasonically pretreating cotton fabric with a 1% sodium dodecyl sulfate solution, and then reacting it sequentially with 6-chlorohexanoyl chloride and N,N-dimethylallylamine; the modifying liquid is prepared by mixing modified chitosan, dimethyl phosphite and 1,4-butanediol; the modified chitosan is prepared by reacting pre-modified chitosan sequentially with oxalyl chloride and 4-hydroxybenzotriazole; the pre-modified chitosan is prepared by pretreating chitosan with 2-bromoisobutyryl bromide, and then grafting acrylic acid and methyl acrylate onto the chitosan using atom transfer radical polymerization.

2. A method for preparing modified cotton fabric, characterized in that, The preparation steps include the following: (1) Chitosan, ethyl acetate, triethylamine, and 2-bromoisobutyryl bromide are mixed evenly in a mass ratio of 2~3:15~25:1:1 and reacted at 200~300 r / min for 1~2 h at room temperature. Pure water of the same mass as triethylamine is added, and the mixture is evaporated at 70~80℃ for 1~2 h. After filtration, the mixture is dried at 0.1~0.2 MPa and 70~80℃ for 10~14 h to obtain pretreated chitosan. Pretreated chitosan, cuprous bromide, N,N-dimethylformamide, acrylic acid, and methyl acrylate are mixed evenly in a mass ratio of 1:0.3~0.4:100~120:5~6:5~6 under nitrogen protection and reacted at 90~100℃ and 200~300 r / min for 24 hours. After 26 hours, the mixture was filtered and washed 3-5 times with anhydrous ethanol. It was then dried at 0.1-0.2 MPa and 0-5°C for 20-24 hours to obtain pre-modified chitosan. Pre-modified chitosan, N,N-dimethylformamide, oxaloyl chloride, and anhydrous diethyl ether were mixed in a mass ratio of 5-7:1:5-7:25-35 and reacted at 200-300 r / min for 8-10 hours at room temperature to obtain acyl-chlorinated chitosan. 4-hydroxybenzotriazole, triethylamine, acyl-chlorinated chitosan, and tetrahydrofuran were mixed uniformly in a mass ratio of 6:3-4:5-6:10-15 and reacted at 0-5°C for 8-10 hours. The mixture was filtered, washed 3-5 times with anhydrous ethanol, and dried at 70-80°C for 10-14 hours to obtain modified chitosan. (2) Soak the cotton fabric in a 1% sodium dodecyl sulfate solution and sonicate for 1-2 hours to remove impurities. Then soak it in pure water and sonicate for 30-50 minutes. Then soak it in anhydrous ethanol and sonicate for 30-50 minutes. Wash it with pure water 3-5 times and finally dry it at 70-80℃ for 8-10 hours to obtain the pretreated cotton fabric. Pretreated cotton fabric is immersed in a chlorination finishing solution and reacted at 0-5℃ for 6-8 hours. Then, it is passed through a rolling mill with a pressure of 1.6-1.8 MPa, and the fabric is left to stand at 100-120℃ for 20-30 minutes, then at 140-160℃ for 4-6 minutes. After naturally cooling to room temperature, it is washed 3-5 times with pure water and then dried at 90℃ for 1-2 hours to obtain chlorinated cotton fabric. Chlorinated cotton fabric is immersed in a pre-modified finishing solution and reacted at room temperature for 6-8 hours. Then, it is passed through a rolling mill with a pressure of 1.6-1.8 MPa, and the fabric is left to stand at 100-120℃ for 20-30 minutes, then at 140-160℃ for 4-6 minutes. After naturally cooling to room temperature, it is washed 3-5 times with pure water and then dried at 90℃ for 1-2 hours to obtain pre-modified cotton fabric. (3) Dimethyl phosphite, modified chitosan, 1,4-butanediol, phosphotungstic acid and N,N-dimethylformamide are mixed evenly at room temperature in a mass ratio of 2~3:8~10:1:0.05~0.07:20~30 to prepare a modified finishing solution; The pre-modified cotton fabric is immersed in the modification solution and reacted at 70~80°C for 4~6 hours. Then, it is passed through a rolling mill with a pressure of 1.6~1.8MPa, and the fabric is left to stand at 100~120°C for 20~30 minutes, then at 140~160°C for 4~6 minutes. After naturally cooling to room temperature, it is washed 3~5 times with pure water and then dried at 90°C for 1~2 hours to obtain the modified cotton fabric.

3. The method for preparing a modified cotton fabric according to claim 2, characterized in that, The chitosan in step (1) is of type C105801.

4. The method for preparing a modified cotton fabric according to claim 2, characterized in that, The chlorination finishing solution in step (2) is prepared by uniformly mixing 6-chlorohexanoyl chloride, triethylamine, and tetrahydrofuran at a mass ratio of 1:1:15~25; the pre-modified finishing solution is prepared by uniformly mixing N,N-dimethylallylamine and n-propanol at a mass ratio of 1:10~20; the weight of the cotton fabric is 150 g / m². 2 .

5. An application of the modified cotton fabric according to claim 1.