Anionic polyvinyl alcohol textile size and preparation method thereof

Abstract

The invention belongs to the technical field of modified polyvinyl alcohol (PVA) sizing agents used for textile warp sizing, and discloses a preparation method of anionic PVA textile sizing agents, which comprises the following steps: firstly treating PVA raw materials with a sodium hydroxide solution to generate sodium polyvinyl alcohol; then, sodium polyvinyl alcohol reacts with an etherifying agent halogenated acetic acid to generate carboxymethyl etherified PVA; according to the method disclosed by the invention, non-ionic PVA can be modified into anionic carboxymethyl PVA, and the anionic carboxymethyl PVA can be efficiently adsorbed by a common cationic adsorbent, so that recycling of PVA slurry in the desizing waste liquid is realized, damage of the desizing waste liquid to a water environment can be greatly reduced, and the method has relatively great application potential.

Description

Technical Field

[0001] The invention relates to the technical field of textile pulp preparation, in particular to an anionic polyvinyl alcohol textile pulp and a preparation method thereof. Background Art

[0002] PVA is a typical water-soluble synthetic polymer obtained by alcoholysis of polyvinyl acetate with methanol. PVA has the characteristics of stable viscosity, good adhesion, high film strength, good elasticity and strong wear resistance. It is one of the most commonly used textile sizing materials with the best comprehensive performance. my country's current total production capacity of PVA has exceeded 1.09 million tons / year, ranking first in the world. As early as the 1940s, PVA was used as a warp sizing material in weaving production; my country's textile field has also widely used PVA for warp sizing since the 1960s. In 2023, the annual usage of PVA sizing in my country has reached about 250,000 tons, ranking first among all synthetic sizing materials. However, PVA is difficult to biodegrade, and its desizing wastewater has caused great environmental pollution, and is called "unclean sizing" by industry insiders. As far as the current production situation is concerned, it is not possible to completely withdraw PVA from the sizing market in the near future due to the limitations of technical level and sizing cost. Therefore, how to enrich and remove PVA from textile printing and dyeing wastewater and then realize its recycling has become a hot issue in the textile industry.

[0003] Among the current methods for treating textile printing and dyeing wastewater, adsorption, as a low-energy solid extraction technology, has incomparable advantages in the treatment of soluble organic and inorganic substances. However, unlike pollutants such as dyes and heavy metal ions in textile printing and dyeing wastewater, PVA is a non-ionic polymer. Commonly used adsorbents (such as zero-valent iron, activated carbon, and alumina) can usually only physically adsorb PVA in wastewater by virtue of their own microporous structure or large specific surface area, and cannot play an electrostatic adsorption role, resulting in poor adsorption effect on PVA. Therefore, it is necessary to explore simple and effective chemical methods to modify PVA, which was originally a non-ionic polymer, into an ionic polymer, so as to help commonly used adsorbents to play both physical adsorption and electrostatic adsorption roles when enriching PVA in wastewater, thereby greatly improving the removal efficiency of PVA. This is of great significance for reducing the pollution of PVA desizing wastewater to the environment and the recycling and regeneration of relatively expensive PVA slurry.

[0004] At present, there are some public documents on the preparation of carboxymethyl etherified anionic polymers; for example, the existing invention patent application CN115286826A discloses a method for preparing carboxymethyl starch. In this method, 10 to 15 parts of starch, 10 to 20 parts of ethanol and 2 to 5 parts of sodium hydroxide are mixed and stirred, 5 to 10 parts of chloroacetic acid are added dropwise and continued to stir, the pH value is adjusted, and the modified carboxymethyl starch white powder is obtained after suction filtration, washing and drying. The purpose of preparing carboxymethyl starch by this process is mainly to improve the solubility of starch in water and reduce the gelatinization temperature of starch, so there is no strict requirement for the degree of substitution of etherified modified starch, and the input amount of etherifying agent chloroacetic acid is relatively small, which is only 1 / 2 to 2 / 3 of the mass of starch substrate.

[0005] The existing invention patent application CN118406161A discloses a preparation process of bamboo-derived sodium carboxymethyl cellulose. The process involves the following steps: 1) salt soaking: dispersing bamboo cellulose in a zinc chloride solution, soaking at 15-35°C for 0.5-3h, draining the solution and harvesting the zinc chloride-containing bamboo cellulose; 2) alkalization: adding the zinc chloride-containing bamboo cellulose to an alkaline solution to harvest the alkaline cellulose; 3) etherification: adding chloroacetic acid to the alkaline cellulose for etherification, and then harvesting the bamboo-derived sodium carboxymethyl cellulose after neutralization, washing and drying. The purpose of preparing sodium carboxymethyl cellulose by this process is mainly to improve the wettability of sodium carboxymethyl cellulose and reduce the energy consumption of the industrial process. Therefore, there is no strict requirement for the degree of substitution of the etherified modified cellulose. The input amount of the etherifying agent chloroacetic acid is small, and the mass ratio of chloroacetic acid to the cellulose substrate is 1:10-1:1.

[0006] In the existing public literature on carboxymethyl etherified anionic polymers, only modified starch, cellulose and other polysaccharide anionic polymers are used in textile pulp. The purpose of carboxymethyl etherification modification is mainly to improve the water solubility of the polymer, and does not involve the problem of using electrostatic adsorption to enrich and remove the pulp in the desizing wastewater, so the requirements for the degree of etherification substitution are generally not high. Polysaccharide polymers such as starch and cellulose have great differences from PVA in many physical and chemical properties (such as water solubility, acid and alkali resistance, and reactivity with halogenated acetic acid), so the reference value of the synthesis technology of carboxymethyl starch and cellulose in the existing literature for the preparation of carboxymethyl PVA pulp is extremely limited.

[0007] There are a few public documents on the preparation of carboxymethyl etherified anionic PVA; for example: the invention patent with application publication number CN105693893A discloses a method for preparing sodium carboxymethyl polyvinyl alcohol, which uses sodium hydroxide and chloroacetic acid as an alkali agent and an etherifying agent, respectively, and controls the amount of feed, feeding time, and reaction time. After two alkalizations and two etherifications, sodium carboxymethyl polyvinyl alcohol with a certain degree of substitution is prepared, aiming to obtain modified sodium polyvinyl alcohol with good water dispersibility and low viscosity. The purpose of this patent is only to improve the water dispersibility of PVA and reduce the viscosity of its solution, so there is no strict requirement for the degree of substitution of etherified modified PVA. In addition, the method disclosed in the patent application is complicated, the preparation process is lengthy, and the etherifying agent used is limited to chloroacetic acid.

[0008] Therefore, it is necessary to develop a method with simple process and optional type of etherifying agent halogenated acetic acid to modify PVA, which is originally a non-ionic polymer, into anionic PVA with a higher degree of substitution, so as to obtain carboxymethyl etherified anionic PVA that can be efficiently adsorbed and removed by commonly used adsorbents without damaging the original good sizing properties of PVA, thereby greatly reducing the pollution of PVA desizing wastewater to the environment and realizing the recovery and utilization of PVA in the desizing wastewater. Summary of the invention

[0009] The present invention provides an anionic PVA textile slurry and a preparation method thereof, and the specific scheme is as follows:

[0010] An anionic polyvinyl alcohol textile pulp, the anionic PVA, has the following molecular structure:

[0011]

[0012] In the above molecular formula, m / (n+m)=0.065-1, X is a halogen atom such as Cl, Br, etc., p+q=2, and p and q are both integers.

[0013] A method for preparing anionic polyvinyl alcohol textile slurry comprises the following steps:

[0014] (1) Alkalization treatment: using water as solvent, prepare sodium hydroxide solution; adding anhydrous ethanol to the sodium hydroxide solution, stirring evenly and cooling to room temperature to obtain a mixed solution I; adding PVA powder to the mixed solution I, heating to 30-40° C., stirring for 1-2 hours, and obtaining an alkaline-treated PVA solution;

[0015] (2) Carboxymethyl etherification treatment: using anhydrous ethanol as solvent, preparing a solution II with halogenated acetic acid; adding the solution II dropwise to the alkalized PVA solution obtained in step (1); heating the solution to 65-75° C. under stirring, reacting the solution for 6-8 hours to obtain a carboxymethyl etherified PVA solution; after the solution is cooled to room temperature, adding anhydrous ethanol to the solution to precipitate the carboxymethyl etherified PVA product;

[0016] (3) Impurity removal and purification: The precipitated product of step (2) is placed in a centrifuge tube and centrifuged at 10,000 rpm for 15 min, and repeatedly washed with an ethanol / water mixture and centrifuged multiple times, and then the carboxymethyl etherified PVA is dissolved in water to form a solution III; the solution III is placed in a dialysis bag and dialyzed with distilled water for 24 h, and the distilled water is replaced every 4 to 6 h. The dialyzed product is freeze-dried to obtain a carboxymethyl etherified PVA slurry.

[0017] In the step (1), in the mixed solution I, the mass ratio of sodium hydroxide to water is 1:2 to 1:2.5, and the mass ratio of sodium hydroxide to anhydrous ethanol is 1:2.4 to 1:3.

[0018] In the step (1), the mass ratio of the PVA powder to the mixed solution I is 1:10-1:15, the degree of polymerization of the PVA powder is 200-1700, and the degree of alcoholysis is 87-99 mol%.

[0019] In the step (2), the halogenated acetic acid is chloroacetic acid, dichloroacetic acid, trichloroacetic acid or bromoacetic acid, and in the solution II, the mass ratio of the halogenated acetic acid to anhydrous ethanol is 3:1 to 3:2, and the mass ratio of the halogenated acetic acid to the PVA powder added to the mixed solution I in the step (1) is 2:1 to 10:1.

[0020] The molecular weight cut-off of the dialysis bag in step (3) is 8000.

[0021] The present invention first selects caustic soda to alkalize the PVA raw material, and forms ions by nucleophilic attack of protonated water molecules on the hydroxyl groups of the alcohol molecules, grabs protons in the reaction system, promotes the rate of the next etherification reaction, and reduces the possibility of side reactions; then, a certain amount of etherifying agent halogenated acetic acid (such as chloroacetic acid, dichloroacetic acid, trichloroacetic acid, bromoacetic acid) is used to carry out carboxymethyl etherification reaction with the alkalized PVA to obtain carboxymethyl etherified anionic PVA. Because commonly used adsorbents (such as zero-valent iron, activated carbon, and aluminum oxide) can carry a large amount of positive charges in the aqueous phase through acid adjustment, electrostatic adsorption and physical adsorption can cooperate with each other to efficiently remove anionic PVA in water. Therefore, the anionic PVA obtained after the etherification reaction with the etherifying agent halogenated acetic acid is easily and efficiently adsorbed by commonly used adsorbents for textile printing and dyeing wastewater, and can be recycled and regenerated after desorption.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The carboxymethyl etherified anionic PVA prepared by the present invention can be efficiently adsorbed by common adsorbents in the aqueous phase. Taking the simulated desizing waste liquid with an initial PVA concentration of 100 mg / L as an example, the removal rate of the anionic PVA by common adsorbents (such as zero-valent iron, activated carbon, and alumina) reached more than 98%.

[0024] (2) The present invention can prepare carboxymethyl PVA with a high degree of substitution by one alkalization and one etherification treatment, thereby simplifying the preparation process and improving production efficiency.

[0025] (3) The present invention expands the optional varieties of etherifying agents such as halogenated acetic acids. In addition to traditional chloroacetic acid, halogenated acetic acids such as dichloroacetic acid, trichloroacetic acid, and bromoacetic acid can also be used as etherifying agents to prepare carboxymethyl etherified anionic PVA according to the method provided by the present invention.

[0026] (4) The present invention adopts washing, centrifugation and dialysis combined treatment to remove impurities and purify, which can more thoroughly remove the impurities contained in the carboxymethyl etherified anionic PVA product, especially the impurities such as sodium chloride therein (because the amount of halogenated acetic acid input is very large, a large amount of sodium halide by-products will be generated during the reaction process, and traditional washing and centrifugation cannot clean the sodium halide by-products, which will not only affect the product purity of the carboxymethyl etherified anionic PVA, but the presence of a large amount of salt will also reduce the solubility of PVA, which is very unfavorable for warp sizing), thereby greatly improving the product purity.

[0027] (5) Since the present invention is mainly used for textile pulp that can be efficiently adsorbed by common adsorbents, the requirements for the degree of substitution of modified PVA are very high, so it is necessary to meet the mass ratio of etherifying agent to PVA of 2:1 to 10:1; in addition, because the amount of etherifying agent is large, in order to ensure the smooth progress of the etherification reaction, the amount of alkali in the present invention is also large; the amounts of etherifying agent and alkali in the present invention are coordinated with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 These are the infrared spectra of unmodified PVA (0#) and carboxymethyl etherified anionic PVA (1#~5#) with different degrees of substitution (the degrees of substitution of 1#~5# are 5.8; 6.5; 7.6; 8.0; 8.9 mol %, respectively).

[0029] Figure 2 The color photograph is of carboxymethyl etherified anionic PVA solution (carboxymethyl PVA substitution degree: 8.0 mol%, initial concentration: 1000 mg / L) when iodine-boric acid indicator is added after being adsorbed by zero-valent iron for different times (zero-valent iron input: 750 mg / L, adsorption temperature: 40°C, pH: 3.0, oscillation speed: 220 r / min).

[0030] Figure 3 Scanning electron microscope images of zero-valent iron before the adsorption test (a) and after adsorbing carboxymethyl etherified anionic PVA (substitution degree: 8.0 mol%, adsorption time: 120 min) from the solution (b). DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with specific embodiments. The following are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto.

[0032] Example 1

[0033] 1) Dissolve 7.4 g of sodium hydroxide in 14.8 mL of distilled water, add 23.4 mL of anhydrous ethanol to the sodium hydroxide solution, transfer the sodium hydroxide ethanol aqueous solution into a 250 mL three-necked flask equipped with a mechanical stirrer, a thermometer and a dropping funnel, add 4.0 g of PVA1799 powder with a dry weight into the three-necked flask under mechanical stirring, heat to 30° C., stir at this temperature for 1 h, and obtain an alkalized PVA solution.

[0034] 2) 8.0 g of chloroacetic acid was dissolved in 3.5 mL of anhydrous ethanol. Under mechanical stirring, the chloroacetic acid ethanol solution was added dropwise to the alkalized PVA solution, and the temperature was raised to 65° C. and stirred at this temperature for 6 h to obtain a carboxymethyl etherified PVA solution; after the carboxymethyl etherified PVA solution was cooled to room temperature, 100 mL of anhydrous ethanol was added thereto to precipitate the carboxymethyl etherified PVA product.

[0035] 3) The precipitated carboxymethyl etherified PVA product was placed in a centrifuge tube and centrifuged at 10000 rpm for 15 min, and washed repeatedly with a mixed solution of ethanol / water (70 / 30, v / v) and centrifuged for multiple times, and then the carboxymethyl etherified PVA was dissolved in 100 mL of water to form a solution; the PVA solution was placed in a dialysis bag with a molecular weight cutoff of 8000, dialyzed with distilled water for 24 h, and the dialyzed product was freeze-dried to obtain a carboxymethyl etherified PVA slurry.

[0036] Example 2

[0037] 1) Dissolve 9.3 g of sodium hydroxide in 18.6 mL of distilled water, add 28.3 mL of anhydrous ethanol to the sodium hydroxide solution, transfer the sodium hydroxide ethanol aqueous solution into a 250 mL three-necked flask equipped with a mechanical stirrer, a thermometer and a dropping funnel, add 5.0 g of PVA1799 powder with a dry weight into the three-necked flask under mechanical stirring, heat to 30 ° C, stir at this temperature for 1 hour, and obtain an alkalized PVA solution.

[0038] 2) Dissolve 13.4 g of chloroacetic acid in 6.0 mL of anhydrous ethanol, add the chloroacetic acid ethanol solution dropwise to the alkalized PVA solution under mechanical stirring, heat to 65° C., and stir at this temperature for 6 hours to obtain a carboxymethyl etherified PVA solution; after the carboxymethyl etherified PVA solution is cooled to room temperature, add 110 mL of anhydrous ethanol thereto to precipitate the carboxymethyl etherified PVA product.

[0039] 3) The precipitated carboxymethyl etherified PVA product was placed in a centrifuge tube and centrifuged at 10000 rpm for 15 min, and washed repeatedly with a mixed solution of ethanol / water (70 / 30, v / v) and centrifuged for multiple times, and then the carboxymethyl etherified PVA was dissolved in 110 mL of water to form a solution; the PVA solution was placed in a dialysis bag with a molecular weight cutoff of 8000, and dialyzed with distilled water for 24 h. The dialyzed product was freeze-dried to obtain a carboxymethyl etherified PVA slurry.

[0040] Example 3

[0041] 1) Dissolve 7.4 g of sodium hydroxide in 16.7 mL of distilled water, add 25.3 mL of anhydrous ethanol to the sodium hydroxide solution, transfer the sodium hydroxide ethanol aqueous solution into a 250 mL three-necked flask equipped with a mechanical stirrer, a thermometer and a dropping funnel, add 3.5 g of PVA1788 powder with a dry weight into the three-necked flask under mechanical stirring, heat to 35 ° C, stir at this temperature for 1.5 h, and obtain an alkalized PVA solution.

[0042] 2) Dissolve 21.0 g of dichloroacetic acid in 13.3 mL of anhydrous ethanol, and add the dichloroacetic acid ethanol solution dropwise to the alkalized PVA solution under mechanical stirring, raise the temperature to 70° C., and stir at this temperature for 7 hours to obtain a carboxymethyl etherified PVA solution; after the carboxymethyl etherified PVA solution is cooled to room temperature, add 120 mL of anhydrous ethanol thereto to precipitate the carboxymethyl etherified PVA product.

[0043] 3) The precipitated carboxymethyl etherified PVA product was placed in a centrifuge tube and centrifuged at 10000 rpm for 15 min, and washed repeatedly with a mixed solution of ethanol / water (70 / 30, v / v) and centrifuged for multiple times, and then the carboxymethyl etherified PVA was dissolved in 120 mL of water to form a solution; the PVA solution was placed in a dialysis bag with a molecular weight cutoff of 8000, and dialyzed with distilled water for 24 h. The dialyzed product was freeze-dried to obtain a carboxymethyl etherified PVA slurry.

[0044] Example 4

[0045] 1) Dissolve 7.4 g of sodium hydroxide in 18.5 mL of distilled water, add 28.1 mL of anhydrous ethanol to the sodium hydroxide solution, transfer the sodium hydroxide ethanol aqueous solution into a 250 mL three-necked flask equipped with a mechanical stirrer, a thermometer and a dropping funnel, add 3.3 g of PVA1788 powder with a dry weight into the three-necked flask under mechanical stirring, heat to 40° C., stir at this temperature for 2 h, and obtain an alkalized PVA solution.

[0046] 2) Dissolve 74.0 g of trichloroacetic acid in 49.3 mL of anhydrous ethanol, add the trichloroacetic acid ethanol solution dropwise to the alkalized PVA solution under mechanical stirring, heat to 75° C., and stir at this temperature for 8 h to obtain a carboxymethyl etherified PVA solution; after the carboxymethyl etherified PVA solution is cooled to room temperature, add 150 mL of anhydrous ethanol to precipitate the carboxymethyl etherified PVA product.

[0047] 3) The precipitated carboxymethyl etherified PVA product was placed in a centrifuge tube and centrifuged at 10000 rpm for 15 min, and washed repeatedly with a mixed solution of ethanol / water (70 / 30, v / v) and centrifuged for multiple times, and then the carboxymethyl etherified PVA was dissolved in 150 mL of water to form a solution; the PVA solution was placed in a dialysis bag with a molecular weight cutoff of 8000, and dialyzed with distilled water for 24 h. The dialyzed product was freeze-dried to obtain a carboxymethyl etherified PVA slurry.

[0048] Example 5

[0049] 1) 8.0 g of sodium hydroxide was dissolved in 16.0 mL of distilled water, 24.4 mL of anhydrous ethanol was added dropwise to the sodium hydroxide solution, and the sodium hydroxide ethanol aqueous solution was transferred into a 250 mL three-necked flask equipped with a mechanical stirrer, a thermometer and a dropping funnel. Under mechanical stirring conditions, 4.3 g of PVA1799 powder with a dry weight was added to the three-necked flask, the temperature was raised to 35° C., and stirred at this temperature for 1 h to obtain an alkalized PVA solution.

[0050] 2) Dissolve 34.4 g of bromoacetic acid in 29.0 mL of anhydrous ethanol, and add the bromoacetic acid ethanol solution dropwise to the alkalized PVA solution under mechanical stirring, raise the temperature to 75° C., and stir at this temperature for 6 hours to obtain a carboxymethyl etherified PVA solution; after the carboxymethyl etherified PVA solution is cooled to room temperature, add 120 mL of anhydrous ethanol thereto to precipitate the carboxymethyl etherified PVA product.

[0051] 3) The precipitated carboxymethyl etherified PVA product was placed in a centrifuge tube and centrifuged at 10000 rpm for 15 min, and washed repeatedly with a mixed solution of ethanol / water (70 / 30, v / v) and centrifuged for multiple times, and then the carboxymethyl etherified PVA was dissolved in 120 mL of water to form a solution; the PVA solution was placed in a dialysis bag with a molecular weight cutoff of 8000, and dialyzed with distilled water for 24 h. The dialyzed product was freeze-dried to obtain a carboxymethyl etherified PVA slurry.

[0052] The degree of substitution of the carboxymethyl etherified anionic PVA prepared in Examples 1 to 5 and the removal rate of PVA by a commonly used textile printing and dyeing wastewater adsorbent were detected. The results are shown in Table 1.

[0053] Table 1 Degree of substitution of carboxymethyl etherified anionic PVA under different treatment processes and removal rate of PVA by commonly used textile printing and dyeing wastewater adsorbents

[0054]

[0055] Note: The initial concentration of PVA in the solution is 100 mg / L, the amount of adsorbent input is 750 mg / L, the adsorption temperature is 40°C, the pH is 3.0, the adsorption time is 2h, and the oscillation speed is 220 r / min.

[0056] The mechanical properties of the sizing yarns of the carboxymethyl etherified anionic PVA prepared in Examples 1 to 5 were tested, and the results are shown in Table 2.

[0057] Table 2 Mechanical properties of carboxymethyl etherified anionic PVA sizing under different treatment processes

[0058]

[0059]

[0060] Note: The PVA sizing warp yarn is 77tex cotton yarn, and the sandpaper used for abrasion resistance test has a mesh size of 800.

[0061] The above content describes the technical principles, beneficial effects and features of the present invention. It should be pointed out that the above is only a preferred implementation mode of the present invention, but is not limited to the above embodiments. For technicians in the technical field to which the present invention belongs, some improvements and optimizations can be made without departing from the content of the present invention, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. An anionic polyvinyl alcohol textile pulp, characterized in that: Its molecular structure is as follows: , Wherein m / (n+m)=0.065-1, X is a halogen atom such as Cl, Br, etc., p+q=2 and p and q are both integers.

2. A method for preparing anionic polyvinyl alcohol textile slurry as claimed in claim 1, characterized in that: The steps include: (1) Alkalization treatment: using water as solvent, prepare sodium hydroxide solution; adding anhydrous ethanol to the sodium hydroxide solution, stirring evenly and cooling to room temperature to obtain a mixed solution I; adding PVA powder to the mixed solution I, heating to 30-40°C, stirring for reaction for 1-2 hours, and obtaining an alkaline-treated PVA solution; (2) Carboxymethyl etherification treatment: using anhydrous ethanol as solvent, halogenated acetic acid is prepared into solution II; solution II is added dropwise to the alkalized PVA solution obtained in step (1), and the temperature is raised to 65-75° C. under stirring, and the reaction is carried out for 6-8 hours to obtain a carboxymethyl etherified PVA solution; after the solution is cooled to room temperature, anhydrous ethanol is added thereto to precipitate the carboxymethyl etherified PVA product; (3) Impurity removal and purification: The precipitated product of step (2) is placed in a centrifuge tube and centrifuged at 10,000 rpm for 15 min, and then washed with an ethanol / water mixture and centrifuged multiple times. The carboxymethyl etherified PVA is then dissolved in water to form a solution III. The solution III is placed in a dialysis bag and dialyzed with distilled water for 24 h, with the distilled water replaced every 4 to 6 h. The dialyzed product is freeze-dried to obtain a carboxymethyl etherified PVA slurry.

3. The method for preparing anionic polyvinyl alcohol textile pulp according to claim 2, characterized in that: In the step (1), in the mixed solution I, the mass ratio of sodium hydroxide to water is 1:2 to 1:2.5, and the mass ratio of sodium hydroxide to anhydrous ethanol is 1:2.4 to 1:

3.

4. The method for preparing an anionic polyvinyl alcohol textile slurry according to claim 2, characterized in that: In the step (1), the mass ratio of the PVA powder to the mixed solution I is 1:10-1:15, the degree of polymerization of the PVA powder is 200-1700, and the degree of alcoholysis is 87-99 mol%.

5. The method for preparing anionic polyvinyl alcohol textile slurry according to claim 2, characterized in that: In the step (2), the halogenated acetic acid is chloroacetic acid, dichloroacetic acid, trichloroacetic acid or bromoacetic acid. In the solution II, the mass ratio of the halogenated acetic acid to anhydrous ethanol is 3:1 to 3:2, and the mass ratio of the halogenated acetic acid to the PVA powder added to the mixed solution I in the step (1) is 2:1 to 10:

1.

6. The method for preparing anionic polyvinyl alcohol textile pulp according to claim 2, characterized in that: The molecular weight cut-off of the dialysis bag in step (3) is 8000.

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