A method for dyeing cotton fabrics with plant pigments catalyzed by laccase

Abstract

The present application provides a method for dyeing cotton fabrics with plant pigments catalyzed by laccase, belonging to the technical field of textile dyeing. Chitosan quaternary ammonium salt is dissolved in deionized water and heated to 60-80 °C. The cotton fabric is impregnated in the modification solution. After modification for 30-45 min, the liquor ratio is 80-90%, and then baking is carried out to obtain the modified cotton fabric. The plant extract is dissolved in acetic acid-sodium acetate buffer solution, and laccase is added to catalyze the plant pigment to dye the modified cotton fabric. After washing and drying, the cotton fabric dyed with the plant extract is obtained. Compared with the traditional plant extract dyeing process, this case avoids the use of metal mordants, improves the dyeing depth of cotton fabrics, and endows cotton fabrics with functional properties such as antibacterial properties and antioxidant properties. The entire dyeing process is green and environmentally friendly.

Description

Technical Field

[0001] The present application relates to a method for dyeing cotton fabric based on laccase-catalyzed plant pigments, belonging to the technical field of textile dyeing. Background Art

[0002] As one of the three major natural pigments, plant pigments are the most widely used, involving various industries such as food, cosmetics, medicine, and textiles. Their green, environmentally friendly, and non-toxic characteristics have become a hot spot in the current development of dyes. Natural plant pigments refer to the pigment components present in the leaves, stems, skins, roots, flowers, and fruits of plants. Through physical and chemical extraction and separation such as solvent extraction, ultrasonic extraction, enzyme-assisted extraction, microwave extraction, and supercritical CO2 fluid method, products without changing the structure of their original active ingredients are obtained. There are hundreds of common plants used as dyes with different color systems, such as madder and safflower in the red system; turmeric and coptis in the yellow system; indigo and indigo in the blue system; comfrey and wild amaranth in the purple system; tea and pomegranate peel in the brown and brown systems; gallnut and walnut peel in the gray and black systems. The above plant pigments contain a variety of active ingredients including glycosides, phenols (monophenols, polyphenols, phenolic acids, quinones, flavonoids, etc.), terpenoid compounds, etc., and can dye textiles under certain conditions.

[0003] Plant dyes have advantages such as environmental protection and degradability. However, for a long time, plant pigment dyeing generally requires the use of mordants or bioenzyme methods to improve the dyeing rate, dyeing depth and color fastness. Traditional mordants such as alum, ferrous oxide, copper oxide, etc. contain heavy metal ions that are harmful to the human body; the bioenzyme method uses green catalysts such as laccase to catalyze the polymerization of phenolic compounds to generate colored polymer products, thereby improving the dyeing effect of plant pigments on cotton fabrics, but there are still some insurmountable problems, such as: CN112593425A discloses a method for directly dyeing cotton fabrics using laccase in combination with walnut green peel extract in a one-bath method, but does not mention the state and enzyme activity of laccase, and high-temperature enzyme dyeing at 80°C is not conducive to the oxidative polymerization reaction; CN113863027A uses sodium periodate to oxidize the hydroxyl group of cotton fabric to aldehyde group, which improves the affinity of cotton fabric with cationic modifier, but loses the mechanical properties of cotton fabric itself. The pigment obtained by laccase catalysis is used to dye cotton fabric, and the process is relatively complicated. Summary of the invention

[0004] In view of this, the present application provides a method for dyeing cotton fabrics based on laccase-catalyzed plant pigments, which not only solves the problems of low affinity and shallow dyeing depth of plant pigments in cotton fabrics, gives the fabrics good color fastness, but also gives the fabric dyeing a healthy and environmentally friendly effect.

[0005] Specifically, the present application is implemented through the following scheme:

[0006] A method for dyeing cotton fabric with plant pigment catalyzed by laccase, comprising the following steps:

[0007] S1. Modification of cotton fabric with chitosan quaternary ammonium salt: Dissolve chitosan quaternary ammonium salt in deionized water to prepare a cotton fabric modification solution; after heating the modification solution to 80 - 85 °C, put in the washed and dried cotton fabric, immerse and react for 30 - 45 min, dip and roll once, with a liquor ratio of 80 - 90%; pre-dry at 80 - 85 °C for 3 - 5 min, and cure at 100 - 120 °C for 1 - 3 min to obtain chitosan quaternary ammonium salt modified cotton fabric;

[0008] S2. Dyeing of cotton fabric with plant pigment: Dissolve the plant pigment in acetic acid - acetate buffer solution with pH = 5.0, put in the modified cotton fabric and laccase, control the bath ratio at 50:1 - 100:1, continuously oscillate at 50 °C, and laccase catalyzes the plant pigment to dye the modified cotton fabric for 4 - 5 h, wash at room temperature until there is no floating color, and air dry to obtain the plant pigment dyed cotton fabric.

[0009] The molecular structure of chitosan is similar to the main component cellulose structure of cotton fabric, and there is a good affinity between the two, with good biodegradability and compatibility, non-toxic and harmless, and it is often used for cationic modification of cotton fabric. However, chitosan has a large number of hydroxyl groups and amino groups, which are extremely easy to form intramolecular or intermolecular hydrogen bonds, and it has poor solubility in water. In this case, chitosan quaternary ammonium salt is used as a modifier to modify cotton fabric, greatly weakening the intermolecular hydrogen bonds of chitosan, improving its water solubility, reducing the negative charge on the surface of cotton fabric, enhancing the adsorption of plant pigment, and when dyeing with plant pigment, a cotton fabric dyeing effect with high color fastness and good dyeing depth can be obtained.

[0010] Further, as a preference:

[0011] In step S1, the concentration of the chitosan quaternary ammonium salt is 10 - 15 g / L (L refers to the total volume of the modification solution), and the modification bath ratio is 30:1 - 50:1.

[0012] In step S1, the cotton fabric is a cotton woven fabric or a cotton knitted fabric that has been washed with deionized water and dried in equilibrium.

[0013] In step S2, the laccase is in a liquid state, with an enzyme activity of 8.3 U / mL and a dosage of 0.075 - 0.1 U / mL.

[0014] In step S2, the plant pigment is one of Chinese gallnut, millettia reticulata, pomegranate peel, and tea polyphenols; the dosages are 5 - 10 g / L for Chinese gallnut, 2 - 5 g / L for millettia reticulata, 2 - 6 g / L for pomegranate peel, and the dyeing solution bath ratio is 50:1 - 100:1.

[0015] In step S2, the cleaning condition is to rinse thoroughly with deionized water at room temperature until the deionized water is clear, colorless and free of impurities, and then air-dry at room temperature for 12 - 24 h.

[0016] The working principle and beneficial effects of this application can be summarized as follows:

[0017] (1) The dyeing system constructed in the present invention is the modification of cotton fabric with chitosan quaternary ammonium salt - laccase - catalyzed plant pigment dyeing of modified cotton fabric. First, the cotton fabric is cationically modified with chitosan quaternary ammonium salt, and then the plant pigment is catalyzed by laccase to oxidize and polymerize to generate a colored compound with a deeper color for dyeing the cotton fabric, improving the effect of plant pigment - dyed cotton fabric.

[0018] (2) The present invention uses a chitosan derivative with better water solubility, namely chitosan quaternary ammonium salt, to carry out cationic modification on cotton fabric, which improves the adsorption of cotton fabric to plant pigment while avoiding the use of heavy metal mordants. In view of the relatively high cost of bio - enzymatic dyeing, the present invention uses the liquid laccase formed by Aspergillus oryzae fermentation as the raw material, which has the advantages of better catalytic effect and lower cost.

[0019] (3) The plant pigments involved in the present invention, such as Chinese gallnut, Millettia reticulata, etc., have good antibacterial, antioxidant, ultraviolet - proof and other properties. Using one of Chinese gallnut, Millettia reticulata, pomegranate peel, and tea polyphenols as the pigment substrate, due to the different structures of each substrate, the chromophore groups are different, the degree of polymerization by laccase - catalyzed polymerization is different, and the affinity with cotton fabric also has certain differences, manifested as different dyeing K / S under the same conditions. After laccase and modification treatment, the dyeing effect is significantly improved. Especially for tea polyphenols, as a complex of polyhydroxy phenolic compounds in tea, it is composed of more than 30 kinds of phenolic substances, and its main component is catechin and its derivatives, and the purity of phenolic substances is relatively high. Through the modification and laccase - coordinated treatment in this case, the cotton fabric can be further endowed with functionality by means of a simple dyeing process. Specific Embodiments

[0020] The technical solutions of the present invention will be further described and illustrated through specific embodiments below, but the embodiments of the present invention are not limited thereto.

[0021] The following chitosan quaternary ammonium salt and laccase are all commercially available and have no special requirements.

[0022] Example 1

[0023] Dissolve 0.3 g of quaternary ammonium salt of chitosan (degree of substitution ≥ 90%, pH value of 1% aqueous solution is about 7.0, water-insoluble matter ≤ 1.0%, fineness 40 mesh) by stirring in an appropriate amount of deionized water to prepare 20 mL of cotton fabric modification solution; after heating the modification solution to 80 °C, put in 0.4 g of washed and dried cotton knitted fabric, impregnate and react for 30 min, dip and roll once, with a liquor pickup of 90%; pre-dry at 80 °C for 5 min and cure at 120 °C for 3 min to obtain quaternary ammonium salt of chitosan modified cotton fabric. Dissolve 0.2 g of Chinese gallnut powder in acetic acid-sodium acetate buffer solution with pH = 5.0. After obtaining 40 mL of Chinese gallnut dye solution, put the modified cotton fabric and 48 μL of laccase (CAS No. 80498-15-3, specification: ≥ 0.5 u / mg solid) into the obtained Chinese gallnut dye solution, and continuously oscillate and react at 50 °C for 4 h, wash at room temperature until there is no floating color, and dry at room temperature.

[0024] Comparative Example 1

[0025] Dissolve 0.2 g of Chinese gallnut powder in acetic acid-sodium acetate buffer solution with pH = 5.0. Put 0.4 g of washed and dried unmodified cotton fabric into the obtained 40 mL of Chinese gallnut dye solution, continuously oscillate and react at 50 °C for 4 h, wash at room temperature until there is no floating color, and dry at room temperature.

[0026] Comparative Example 2

[0027] Dissolve 0.2 g of Chinese gallnut powder in acetic acid-sodium acetate buffer solution with pH = 5.0. After obtaining 40 mL of Chinese gallnut dye solution, put in the dried unmodified cotton fabric and 48 μL of laccase, continuously oscillate and react at 50 °C for 4 h, wash at room temperature until there is no floating color, and dry at room temperature.

[0028] Comparative Example 3

[0029] Dissolve 0.3 g of quaternary ammonium salt of chitosan by stirring in an appropriate amount of deionized water to prepare 20 mL of cotton fabric modification solution; after heating the modification solution to 80 °C, put in 0.4 g of washed and dried cotton knitted fabric, impregnate and react for 30 min, dip and roll once, with a liquor pickup of 90%; pre-dry at 80 °C for 5 min and cure at 120 °C for 3 min to obtain quaternary ammonium salt of chitosan modified cotton fabric. Dissolve 0.2 g of Chinese gallnut powder in acetic acid-sodium acetate buffer solution with pH = 5.0. After obtaining 40 mL of Chinese gallnut dye solution, put in the modified cotton fabric, continuously oscillate and react at 50 °C for 4 h, wash at room temperature until there is no floating color, and dry at room temperature.

[0030] Example 2

[0031] 0.3 g of quaternary ammonium salt of chitosan was stirred and dissolved in an appropriate amount of deionized water to prepare 20 mL of a cotton fabric modification solution. After the modification solution was heated to 80 °C, 0.4 g of washed and dried cotton knitted fabric was put in, and the impregnation reaction was carried out for 30 min, one dip and one roll, and the liquor pickup rate was 90%; pre-dried at 85 °C for 3 min and cured at 120 °C for 3 min to obtain the quaternary ammonium salt of chitosan modified cotton fabric. 0.2 g of Millettia reticulata Benth. powder was dissolved in acetic acid - acetate buffer solution with pH = 5.0. The modified cotton fabric and 48 μL of laccase were added to the obtained 40 mL of Millettia reticulata Benth. dyeing solution, and the continuous oscillation reaction was carried out at 50 °C for 4 h, washed at room temperature until there was no floating color, and dried at room temperature.

[0032] Comparative Example 4

[0033] 0.2 g of Millettia reticulata Benth. powder was dissolved in acetic acid - acetate buffer solution with pH = 5.0. After obtaining 40 mL of Millettia reticulata Benth. dyeing solution, unmodified cotton fabric was added, and the continuous oscillation reaction was carried out at 50 °C for 4 h, washed at room temperature until there was no floating color, and dried at room temperature.

[0034] Comparative Example 5

[0035] 0.2 g of Millettia reticulata Benth. powder was dissolved in acetic acid - acetate buffer solution with pH = 5.0. The dry unmodified cotton fabric and 48 μL of laccase were added to the obtained 40 mL of Millettia reticulata Benth. dyeing solution, and the continuous oscillation reaction was carried out at 50 °C for 4 h, washed at room temperature until there was no floating color, and dried at room temperature.

[0036] Example 3

[0037] 0.3 g of quaternary ammonium salt of chitosan was stirred and dissolved in an appropriate amount of deionized water to prepare 20 mL of a cotton fabric modification solution. After the modification solution was heated to 80 °C, 0.4 g of washed and dried cotton knitted fabric was put in, and the impregnation reaction was carried out for 30 min, one dip and one roll, and the liquor pickup rate was 90%; pre-dried at 80 °C for 5 min and cured at 110 °C for 5 min to obtain the quaternary ammonium salt of chitosan modified cotton fabric. 0.2 g of Punica granatum L. peel powder was dissolved in acetic acid - acetate buffer solution with pH = 5.0. After obtaining 40 mL of Punica granatum L. peel dyeing solution, the modified cotton fabric and 48 μL of laccase were added to the Punica granatum L. peel dyeing solution, and the continuous oscillation reaction was carried out at 50 °C for 4 h, washed at room temperature until there was no floating color, and dried at room temperature.

[0038] Example 4

[0039] Dissolve 0.3 g of quaternary ammonium salt of chitosan in an appropriate amount of deionized water to prepare 20 mL of a cotton fabric modification solution. After heating the modification solution to 80 °C, add 0.4 g of washed and dried cotton knitted fabric, immerse and react for 30 min, dip and roll once, with a liquor ratio of 90%; pre-dry at 80 °C for 5 min and cure at 120 °C for 3 min to obtain quaternary ammonium salt of chitosan modified cotton fabric. Dissolve 0.16 g of 98% (purity) tea polyphenol powder in an acetic acid - acetate buffer solution with pH = 5.0 to obtain 40 mL of a tea polyphenol dyeing solution. Then, add the modified cotton fabric and 48 μL of laccase to the tea polyphenol dyeing solution, and react continuously with shaking at 50 °C for 4 h. Wash at room temperature until there is no floating color, and dry at room temperature.

[0040] Performance Testing

[0041] The dyed cotton fabric is equilibrated in a constant temperature and humidity chamber (temperature 20 °C, humidity 65%) for 24 h for testing.

[0042] For testing the K / S value of the dyeing depth, use a D65 light source and a 10° viewing angle to measure the L*, a*, b* values and K / S value of the dyed cotton fabric.

[0043] For the antibacterial performance test, refer to GB / T 20944—2008 "Evaluation of antibacterial properties of textiles: Part 3 Oscillation method". Use Staphylococcus aureus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria.

[0044] For the anti-ultraviolet performance, refer to GB / T 18830-2009 "Determination of anti-ultraviolet properties of textiles".

[0045] For the color fastness to rubbing, refer to GB / T 3920 2008 "Textiles - Tests for color fastness - Color fastness to rubbing".

[0046] For the color fastness to soaping, refer to GB / T 3921 2008 "Textiles - Tests for color fastness - Color fastness to soaping".

[0047] For the color fastness to light, refer to GB / T 8427 2008 "Textiles - Tests for color fastness to artificial light: Xenon arc".

[0048] The test results are shown in Table 1 - Table 4.

[0049] Table 1: K / S value of the dyed cotton fabric

[0050] Serial number K / S value L* a* b* Example 1 15.4390 39.17 5.93 19.85 Example 2 5.4831 50.77 15.21 29.22 Example 3 15.0600 46.41 9.44 27.66 Example 4 7.4346 51.74 14.52 27.70 Comparative example 1 0.9007 81.26 1.72 13.78 Comparative example 2 2.3866 69.98 3.11 18.99 Comparative example 3 0.5874 76.39 7.86 14.75 Comparative example 4 0.9197 72.19 10.73 17.23 Comparative example 5 1.1599 70.86 10.30 20.36

[0051] Table 2: Antibacterial performance of the dyed cotton fabric

[0052] Inhibitory rate against Escherichia coli / % Inhibitory rate against Staphylococcus aureus / % Example 1 99.9 99.9 Example 2 97.8 98.3 Example 3 98.9 99.2 Example 4 95.1 93.5 Comparative example 1 83.3 90.0 Comparative example 2 88.5 93.7 Comparative example 3 92.2 89.6 Comparative example 4 89.4 91.2 Comparative example 5 92.6 90.0

[0053] Table 3: Anti-ultraviolet performance of the dyed cotton fabric

[0054] TUVA / % TUVB / % Protection factor Example 1 1.8 1.9 <![CDATA[50 + > Example 2 1.8 2.0 <![CDATA[50 + > Example 3 2.8 2.6 <![CDATA[50 + > Example 4 2.4 1.5 <![CDATA[50 + > Comparative example 1 3.1 2.9 <![CDATA[40 + > Comparative example 2 2.5 2.6 <![CDATA[50 + > Comparative example 3 1.8 2.0 <![CDATA[40 + > Comparative example 4 2.3 2.2 <![CDATA[40 + > Comparative example 5 1.5 1.2 <![CDATA[50 + >

[0055] Table 4: Color fastness of dyed cotton fabrics

[0056]

[0057]

[0058] It can be seen from comparing Table 1 to Table 4 that:

[0059] (1) It can be seen from comparing Examples 1 - 4 that: Under basically equivalent conditions, by using the dyeing process of the present application, the dyeing depth K / S can reach around 15, the antibacterial rate against Escherichia coli is above 95%, the antibacterial rate against Staphylococcus aureus is above 93.5%, and the protection coefficient is above 50+. The dyeing method in this case not only improves the dyeing effect of plant pigments on cotton fabrics (see Tables 1 and 4), but also endows the cotton fabrics with antibacterial and antioxidant properties (see Tables 2 and 3).

[0060] (2) It can be seen from comparing Example 1 with Comparative Example 3 that when the modified cotton fabric is used as the treatment object, when laccase is used to catalyze the production of a colored dye solution from Chinese gallnut, the dyeing effect of the cotton fabric is significantly better than that of the cotton fabric without laccase, which is also confirmed in the comparison between Comparative Example 1 and Comparative Example 2; it can be seen from comparing Example 1 with Comparative Example 2 that when laccase is used to catalyze the production of a colored dye solution from Chinese gallnut, the dyeing effect of the modified cotton fabric is much better than that of the unmodified cotton fabric; at the same time, it also shows that for Chinese gallnut pigment, simple modification has little effect on improving the dyeing depth, but combined with the enzymatic catalytic polymerization of laccase, it has a great effect on increasing the K / S value of cotton fabric dyeing.

[0061] It can be seen from comparing Example 2 with Comparative Examples 4 - 5 that the above characteristics also exist when the powder of Millettia reticulata Benth. is used as the plant pigment.

[0062] After the above - mentioned scheme modifies the cotton fabric with quaternary ammonium salt of chitosan and then combines with laccase to catalyze the dyeing of plant pigments on the cotton fabric, compared with conventional plant pigment dyeing, it can endow the cotton fabric with better dye uptake rate and color fastness, while avoiding the use of heavy metal mordants and damaging the basic properties of the cotton fabric, and improving the adsorption of the cotton fabric to plant pigments.

[0063] The above - mentioned is the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle described in the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for dyeing cotton fabrics with plant pigments catalyzed by laccase, characterized in that, It includes the following steps: Step 1: Stir and dissolve 0.3 g of quaternary ammonium salt of chitosan in deionized water to prepare 20 mL of a modified solution; After the modified solution is heated to 80 °C, add 0.4 g of cotton knitted fabric, impregnate and react for 30 min, dip-roll once, with a liquor pickup of 90%; pre-bake at 80 °C for 5 min and cure at 120 °C for 3 min to obtain the quaternary ammonium salt of chitosan modified cotton fabric; Step 2: Dissolve 0.16 g of 98% tea polyphenol powder in an acetic acid - acetate buffer solution with pH = 5.

0. After obtaining 40 mL of tea polyphenol dye solution, add the modified cotton fabric and 48 μL of laccase to the tea polyphenol dye solution, and continuously oscillate and react at 50 °C for 4 h. Wash at room temperature until there is no floating color, and air dry at room temperature.

2. A method for dyeing cotton fabrics with plant pigments catalyzed by laccase, characterized in that, It includes the following steps: Step 1: Stir and dissolve 0.3 g of quaternary ammonium salt of chitosan in deionized water to prepare 20 mL of a modified solution; After the modified solution is heated to 80 °C, add 0.4 g of cotton knitted fabric, impregnate and react for 30 min, dip-roll once, with a liquor pickup of 90%; pre-bake at 80 °C for 5 min and cure at 120 °C for 3 min to obtain the quaternary ammonium salt of chitosan modified cotton fabric; Step 2: Dissolve 0.2 g of Chinese gallnut powder in an acetic acid - acetate buffer solution with pH = 5.

0. After obtaining 40 mL of Chinese gallnut dye solution, add the modified cotton fabric and 48 μL of laccase to the obtained Chinese gallnut dye solution, and continuously oscillate and react at 50 °C for 4 h. Wash at room temperature until there is no floating color, and air dry at room temperature.

3. A method for dyeing cotton fabrics with plant pigments catalyzed by laccase, characterized in that, It includes the following steps: Step 1: Stir and dissolve 0.3 g of quaternary ammonium salt of chitosan in deionized water to prepare 20 mL of a modified solution; After the modified solution is heated to 80 °C, add 0.4 g of cotton knitted fabric, impregnate and react for 30 min, dip-roll once, with a liquor pickup of 90%; pre-bake at 85 °C for 3 min and cure at 120 °C for 3 min to obtain the quaternary ammonium salt of chitosan modified cotton fabric; Step 2: Dissolve 0.2 g of Millettia reticulata Benth. powder in an acetic acid - acetate buffer solution with pH = 5.

0. Add the modified cotton fabric and 48 μL of laccase to the obtained 40 mL of Millettia reticulata Benth. dye solution, and continuously oscillate and react at 50 °C for 4 h. Wash at room temperature until there is no floating color, and air dry at room temperature.

4. A method for dyeing cotton fabrics with plant pigments catalyzed by laccase, characterized in that, It includes the following steps: Step 1: Stir and dissolve 0.3 g of quaternary ammonium salt of chitosan in deionized water to prepare 20 mL of a modified solution; After the modified solution is heated to 80 °C, add 0.4 g of cotton knitted fabric, impregnate and react for 30 min, dip-roll once, with a liquor pickup of 90%; pre-bake at 80 °C for 5 min and cure at 110 °C for 5 min to obtain the quaternary ammonium salt of chitosan modified cotton fabric; Step 2: Dissolve 0.2 g of pomegranate peel powder in an acetic acid - acetate buffer solution with pH = 5.

0. After obtaining 40 mL of pomegranate peel dye solution, add the modified cotton fabric and 48 μL of laccase to the pomegranate peel dye solution, and continuously oscillate and react at 50 °C for 4 h. Wash at room temperature until there is no floating color, and air dry at room temperature.

Images