CN111826951A - A kind of method using succinic acid to prepare high carboxyl content modified cotton fabric - Google Patents

Abstract

The invention relates to a method for preparing modified cotton fabrics with high carboxyl group content by using succinic acid, which is characterized in that the appearance of the modified cotton fabrics prepared by the method is in the shape of brown-yellow fabrics, wherein the carboxyl group content ranges from 0.4 mmol per gram to 1.0 mmol per gram. millimoles per gram. Succinic acid is easier to esterify with the hydroxyl groups in the macromolecular chain of cotton fibers, and can more effectively introduce carboxyl groups on the surface of cotton fibers to achieve the purpose of reducing the amount of carboxylic acid in the carboxylic acid modified finishing process of cotton fibers. The preparation method simplifies the cotton fiber carboxylic acid modification finishing process, reduces the processing cost, reduces the environmental pollution, achieves the purpose of energy saving and emission reduction, and shows a bright industrialization prospect.

Description

A kind of method using succinic acid to prepare high carboxyl content modified cotton fabric

technical field

The invention relates to the technical field of chemical industry, in particular to a method for preparing modified cotton fabric with high carboxyl group content by using succinic acid.

Background technique

Cotton fiber is the main raw material of my country's textile industry. In the production and processing of cotton textiles, a large amount of short fibers, waste yarn, noil and corner waste are often produced. If these wastes are directly discarded without certain treatment, it will bring a huge burden to the environment and also cause a large degree of waste of resources. my country produces and consumes a huge amount of textiles, resulting in tens of billions of tons of textile waste every year. Therefore, converting these textile wastes into usable resources as much as possible and turning wastes into treasures has become a serious problem faced by the textile industry. It is worth noting that in order to make better use of waste cotton fabric, its carboxylation modification is an important basic work, because carboxylation modification can not only make cotton fabrics have higher adsorption of heavy metal ions and organic dyes, but also Moreover, the modified cotton fiber metal complex catalyst can be further prepared by coordination reaction with iron ions, etc., which can promote the oxidative degradation of organic pollutants in water, and is of great significance for controlling water environmental pollution. In the carboxylation modification technology of cotton fabrics, organic carboxylic acids such as tartaric acid and citric acid are often used to esterify the surface to introduce carboxyl groups [see Liu G, Dong Y, Wang P, et al. Activation of Na ₂ S ₂ O ₈ for dye degradation by Fe complexes fixed onpolycarboxylic acids modified waste cotton[J].Carbohydr Polym, 2018: 103-110.], but tartaric acid and citric acid are not efficient in introducing carboxyl groups on the surface of cotton fibers, that is, high concentrations of Only the tartaric acid and citric acid can increase the carboxyl content on the surface of the cotton fiber, which not only causes serious waste of tartaric acid and citric acid in the reaction process, but also brings certain environmental pollution problems. The present invention uses succinic acid instead of tartaric acid and citric acid to modify the surface of cotton fibers to introduce carboxyl groups, which can not only make the modified cotton fibers have higher carboxylic acid content, but also can significantly reduce the amount of organic carboxylic acids.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a method for preparing modified cotton fibers with high carboxyl content by using succinic acid. The modified cotton fiber of the present invention can improve the efficiency of introducing carboxyl groups on the surface of the cotton fiber, avoid waste of organic acids in the modification process, and reduce environmental pollution. This simplifies the cotton fiber carboxylic acid modification reaction process, reduces the cost, is easy to operate, and is beneficial to industrialization.

The technical solution of the present invention to solve the problem of carboxylic acid modification of cotton fiber is: a method for preparing modified cotton fiber with high carboxyl group content by using succinic acid, which is characterized in that succinic acid is more likely to be combined with the macromolecular chain of cotton fiber. The hydroxyl group undergoes an esterification reaction, which is more effective in introducing carboxyl groups on the surface of cotton fibers than tartaric acid and citric acid. The purpose of significantly reducing the amount of carboxylic acid in the process simplifies the cotton fiber carboxylic acid modification process, reduces processing costs, reduces environmental pollution, and achieves the purpose of energy saving and emission reduction. In the carboxylic acid modification reaction of cotton fiber, when the amount of succinic acid reaches 0.17 mol per liter, the carboxyl group content of the modified cotton fiber obtained is 0.50 mmol per gram. In order to make the carboxyl group content of the modified cotton fiber reach 0.50 mmol per gram, more than 0.70 mol per liter of tartaric acid must be used, so the amount of organic carboxylic acid can be reduced by four-fifths.

The technical scheme of the present invention to solve the technical problem of the preparation method is: design a method for preparing the modified cotton fiber with high carboxyl content using succinic acid, which adopts the following process:

1. Pretreatment of cotton fabrics: Under room temperature and stirring conditions, cotton fabrics are placed in an aqueous solution containing 5 grams per liter of anionic detergent and 2 grams per liter of sodium carbonate, and treated under boiling conditions for 30 minutes, Then take out the fabric and wash it three times, and finally dry it at 100°C;

2. Preparation of the modified liquid: put the specified weights of succinic acid and sodium dihydrogen phosphate into distilled water, stir to dissolve them completely, and prepare succinic acid and succinic acid with a concentration of 20.08 grams per liter and 80.30 grams per liter. An aqueous solution of 50 grams per liter of sodium dihydrogen phosphate, and finally the resulting mixed aqueous solution is allowed to stand for 2 to 5 hours;

3. Pad-baking treatment process: using the above-mentioned modification liquid to modify the pretreated cotton fabric described in step 1 by means of a pad-baking-baking combined system to obtain a succinic acid-modified cotton fabric;

4. Post-treatment process: under room temperature and stirring conditions, the succinic acid-modified cotton fabric described in step 3 was first washed with an aqueous solution of anionic surfactant with a concentration of 2.5 grams per liter for 8 minutes, and then washed with distilled water. 3 times, and finally dried at 100 °C to obtain a light yellow succinic acid-modified cotton fabric.

Compared with the prior art, the modified cotton fiber prepared by using succinic acid in the present invention has higher carboxylic acid content. In the preparation process, the amount of organic carboxylic acid is not only greatly reduced, but also the carboxyl group is more effectively introduced into the surface of the cotton fiber, which not only improves the utilization rate of the organic carboxylic acid, but also increases the carboxylic acid content on the surface of the modified cotton fiber. This simplifies the cotton fiber modification reaction process, significantly reduces the cost, is easy to operate, and is beneficial to industrialization.

Description of drawings

Fig. 1 is the carboxyl content of succinic acid-modified cotton fabric described in embodiment 1-4;

Figure 2 shows the carboxyl group content of the succinic acid-modified cotton fabrics described in Examples 1-4 and Comparative Examples 1-4.

Detailed ways

The technical solution of the present invention to solve the problem of carboxylic acid modification of cotton fiber is: a method for preparing modified cotton fiber with high carboxyl group content by using succinic acid, which is characterized in that succinic acid is more likely to be combined with the macromolecular chain of cotton fiber. The hydroxyl group undergoes esterification reaction, which is more effective to introduce carboxyl groups on the surface of cotton fibers than tartaric acid and citric acid. The purpose of reducing the amount of carboxylic acid in the process simplifies the cotton fiber carboxylic acid modification process, reduces processing costs, reduces environmental pollution, and achieves the purpose of energy saving and emission reduction. In the carboxylic acid modification reaction of cotton fiber, when the amount of succinic acid reaches 0.17 moles per liter, the carboxyl group content of the modified cotton fibers obtained is 0.50 mmol per gram; millimoles per gram, more than 0.70 moles per liter of tartaric acid must be used, thus reducing the amount of organic carboxylic acid by four-fifths.

In the embodiment of the present invention, the carboxyl content of succinic acid-modified cotton fibers is determined as follows: first, 0.50 g of tartrate-succinic acid-modified cotton fibers cut into pieces are placed in 50 ml of sodium hydroxide with a concentration of 0.10 mol per liter. aqueous solution, and allowed to react for 2 hours at room temperature under stirring and nitrogen protection. The phenolphthalein indicator was then added and the residual sodium hydroxide therein was titrated with a standard solution of 0.10 moles per liter of hydrochloric acid. When the red color of the aqueous solution in the system faded (the end point of the titration), the volume of the hydrochloric acid solution consumed was recorded, and the surface carboxylic acid content per unit mass of organic carboxylic acid-modified cotton fibers (Q _COOH , mmol per gram) was calculated using the following formula:

In the formula, C _NaOH and V _NaOH are the concentration (0.10 mol per liter) and volume (50 ml) of aqueous sodium hydroxide solution, respectively, C _HCl is the concentration of the standard solution of hydrochloric acid (0.10 mol per liter), and V _HCl is the hydrochloric acid consumed by the titration. Standard solution volume (ml), m is the mass of organic carboxylic acid modified cotton fiber (0.50 g).

Specific embodiments of the present invention are introduced below, but the claims of the present invention are not limited by these specific embodiments:

Example 1

1. Pretreatment of cotton fabrics: Under room temperature and stirring conditions, cotton fabrics are placed in an aqueous solution containing 5 grams per liter of anionic detergent and 2 grams per liter of sodium carbonate, and treated under boiling conditions for 30 minutes, Then the fabric is taken out and rinsed 3 times, and finally dried at 100°C;

2. Preparation of the modified liquid: put the specified weights of succinic acid and sodium dihydrogen phosphate into distilled water, stir to dissolve them completely, and prepare succinic acid with a concentration of 20.08 grams per liter and 50 grams per liter of phosphoric acid. An aqueous solution of sodium dihydrogen, and finally the resulting mixed aqueous solution is allowed to stand for 2 to 5 hours;

3. Padding and baking treatment process: using the above-mentioned modification liquid to carry out modification treatment by means of the pretreated cotton fabric described in step 1 of the padding-baking combined system to obtain a succinic acid-modified cotton fabric;

4. Post-treatment process: Under the condition of room temperature and stirring, firstly use an anionic surfactant aqueous solution with a concentration of 2.5 grams per liter to wash and treat the above-mentioned modified cotton fabric for 8 minutes, then take it out, and then use distilled water to wash it 3 times , and finally dried at 100° C. to obtain a light yellow succinic acid-modified cotton fabric with a carboxylic acid content of 0.50 mmol per gram.

Example 2

1. Process is identical with step 1 in Example 1;

2. The succinic acid concentration is set to be 40.15 grams per liter, and other processes are the same as step 2 in Example 1;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the obtained succinic acid-modified cotton fabric is 0.64 mmol per gram.

Example 3

1. Process is identical with step 1 in Example 1;

2. The succinic acid concentration is set to be 60.23 grams per liter, and other processes are the same as step 2 in Example 1;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the obtained succinic acid-modified cotton fabric is 0.70 mmol per gram.

Example 4

1. Process is identical with step 1 in Example 1;

2. The succinic acid concentration is set to be 80.30 grams per liter, and other processes are the same as step 2 in Example 1;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the obtained succinic acid-modified cotton fabric is 0.78 mmol per gram.

Comparative ratio

This embodiment is an effect comparison example. Use tartaric acid to replace succinic acid to prepare carboxylic acid modified cotton fabric, and its technological method is as follows:

Comparative Example 1

1. Process is identical with step 1 in Example 1;

2. Preparation of modified liquid: put the specified weights of tartaric acid and sodium dihydrogen phosphate into distilled water, stir to dissolve completely, and prepare a solution containing 11.8 grams per liter of tartaric acid and 50 grams per liter of sodium dihydrogen phosphate. aqueous solution, and finally the resulting mixed aqueous solution is allowed to stand for 2 to 5 hours;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the tartaric acid-modified cotton fabric is 0.11 mmol per gram.

Example 2

1. Process is identical with step 1 in Example 1;

2. The tartaric acid concentration is set to be 51.03 grams per liter, and other processes are identical with step 2 in Example 1;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the tartaric acid-modified cotton fabric is 0.24 mmol per gram.

Example 3

1. Process is identical with step 1 in Example 1;

2. The tartaric acid concentration is set to be 76.55 grams per liter, and other processes are identical to step 2 in Example 1;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the tartaric acid-modified cotton fabric is 0.34 mmol per gram.

Example 4

1. Process is identical with step 1 in Example 1;

2. The tartaric acid concentration is set to be 102.07 grams per liter, and other processes are identical with step 2 in Example 1;

3. Process is identical with step 3 in Example 1;

4. The process is the same as step 4 in Example 1, and the carboxylic acid content of the tartaric acid-modified cotton fabric is 0.45 mmol per gram.

Figure 1 shows that when the amount of succinic acid reaches 0.17 moles per liter, the carboxyl group content of the modified cotton fibers is 0.50 mmol per gram; with the increase of the amount of succinic acid, the carboxyl group content of the modified cotton fibers increases almost linearly . When the amount of succinic acid reaches 0.68 moles per liter, the carboxyl group content of the obtained modified cotton fibers is 0.78 mmoles per gram.

Figure 2 shows that the carboxylic acid content of succinic acid-modified cotton fabrics with the same molar concentration is significantly higher than that of tartaric acid-modified cotton fabrics, especially at low concentrations. This proves that the use of succinic acid instead of tartaric acid to modify cotton fabrics not only significantly reduces the amount of organic carboxylic acids, but also introduces carboxyl groups on the surface of cotton fibers more effectively, which not only improves the utilization of organic carboxylic acids, but also The carboxylic acid content on the surface of modified cotton fibers was increased.

Comparing Figure 1 and Figure 2, it can be seen that when using succinic acid instead of tartaric acid for cotton fiber modification, the amount of organic carboxylic acid can be significantly saved, especially when using low concentration of organic carboxylic acid for modification, it can be reduced by at least five points. Fourth, the amount of organic carboxylic acid.

The above-mentioned embodiments only represent the embodiments of the present invention, and the descriptions thereof are specific and detailed, but should not be construed as limiting the scope of the patent of the present invention. It should be pointed out that for those skilled in the art, without departing from the concept of the present invention, several improvements can be made, and these improvements all belong to the protection scope of the present invention.

Claims (1)

1. A method for preparing modified cotton fabric with high carboxyl content by using succinic acid adopts the following process:

step 1: pretreatment of cotton fabric: placing the cotton fabric in an aqueous solution containing 5.0 g per liter of anionic detergent and 2.0 g per liter of sodium carbonate at room temperature under stirring, treating for 30 minutes under boiling, taking out the fabric, washing for 3 times, and drying at 100 ℃;

step 2: preparing a modified solution: respectively putting succinic acid and sodium dihydrogen phosphate with specified weight into distilled water, stirring to completely dissolve, preparing aqueous solution containing succinic acid with concentration of 11.8-82.6 g/L and sodium dihydrogen phosphate with concentration of 50 g/L, and standing the obtained mixed aqueous solution for 2-5 hours;

and step 3: the rolling and baking treatment process comprises the following steps: modifying the pretreated cotton fabric obtained in the step 1 by using the modifying solution through a rolling and baking combined system to obtain a succinic acid modified cotton fabric;

and 4, step 4: and (3) post-treatment process: and (2) washing the succinic acid modified cotton fabric obtained in the step (3) for 8 minutes by using an anionic surfactant aqueous solution with the concentration of 2.5 grams per liter at room temperature under the stirring condition, then washing the succinic acid modified cotton fabric for 3 times by using distilled water, and finally drying the succinic acid modified cotton fabric at 100 ℃ to obtain the light yellow succinic acid modified cotton fabric.

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