Method for preparing modified starch bio-based slurry, and product and use thereof

Abstract

The present application relates to a method for preparing a modified starch bio-based slurry, and a product and the use thereof. The preparation method comprises the following steps: mixing starch, a bio-based emulsifier, an alkaline solution and sodium chloroacetate, then reacting the resulting mixture to obtain a reactant, adjusting the pH of the reactant to 5-8, and then filtering and washing same to obtain the modified starch bio-based slurry, wherein the bio-based emulsifier is cardanol polyoxyethylene ether. The hydroxyl on starch in the present application is activated under the catalytic action of an alkali and then reacts with an etherifying agent, such that a carboxymethyl group is introduced to a starch molecular chain; in addition, a specific bio-based emulsifier is added during the process, which can facilitate better penetration of the alkali and sodium chloroacetate inside the starch and improve the reaction efficiency, thereby enhancing the stability of the reaction product and the performance of a slurry film.

Description

Preparation method of modified starch bio-based sizing material, product and application thereof TECHNICAL FIELD

[0001] The present application belongs to the field of textiles, and particularly relates to a preparation method of modified starch bio-based sizing material, product and application thereof. BACKGROUND

[0002] The warp yarn is repeatedly stretched and bent more than 4000 times from the back beam of the loom to the weaving mouth; the friction between the warp yarns and the friction between the warp yarns and the eyelet, shuttle board and weft guide are quite intense, all of which exceed the wear resistance of the original yarn on the weft. In order to reduce the warp yarn breakage rate, improve the weavability of the warp yarn and the product quality, the warp yarn must be endowed with higher wear resistance, the hairiness on the surface of the yarn is attached, the strength of the warp yarn is appropriately increased, and the original elasticity of the warp yarn is preserved as much as possible. Therefore, sizing is a key process in the preparation of warp yarn before weaving.

[0003] Starch has a long history as the main sizing material for sizing. Starch is widely available, inexpensive and biodegradable. At present, starch accounts for 70% of all textile sizing materials. The advantages of starch sizing material are good adhesion to cellulose fibers, film forming property, very high breaking strength and elongation at break, and excellent fatigue resistance. However, the adhesion of starch sizing material to high-count high-density cotton fibers is poor, the hairiness attachment performance is poor, the shedding is much, and the yarn breakage rate is high, which seriously affects the weaving efficiency of the yarn.

[0004] Starch is composed of amylose and amylopectin, and the amylose is a linear macromolecule connected by alpha-1, 4 glycosidic bonds. The molecular weight of amylose is much smaller than that of amylopectin, and the water solubility of amylose in hot water is good. The sizing viscosity of amylose is small, and the penetration performance is strong, but the aging and retrogradation of amylose is easy, which is not conducive to the penetration performance and film forming property of amylose, and limits its application in textile sizing materials. In order to improve the performance of starch and expand its application range, new functional groups are introduced into the starch molecules or the size and particle properties of the starch molecules are changed by physical, chemical or enzymatic treatment, so as to change the natural properties of starch, such as gelatinization temperature, thermal viscosity and stability, freeze-thaw stability, gel strength, film forming property, transparency, etc., so as to make it more suitable for certain application requirements.

[0005] There are two main types of starch modification in the prior art, one is dry method and the other is wet method. The wet method has a complex process, long time consumption and high energy consumption. The dry method has a simple process, short time consumption, but the chemical reagents and starch are not mixed uniformly in the preparation process due to no water or too little water, which leads to insufficient reaction, easy caking and unstable product yield. Therefore, it is of great significance to provide a starch modification method with excellent sizing film performance and high product stability.

[0006] SUMMARY

[0007] The following is a summary of the subject matter of the detailed description herein. This summary is not intended to limit the scope of the claims.

[0008] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation method of modified starch bio-based sizing material, its product and application, especially to provide a preparation method of modified starch bio-based sizing material and its product and application in textiles.

[0009] To achieve this purpose, the following technical solutions are adopted in the present application:

[0010] In a first aspect, the present application provides a preparation method of modified starch bio-based sizing material, which comprises the following steps:

[0011] The starch, bio-based emulsifier, alkaline solution and sodium chloroacetate are mixed and then reacted to obtain a reaction product. The pH of the reaction product is adjusted to 5-8, and then the modified starch bio-based sizing material is obtained after filtration and washing.

[0012] The bio-based emulsifier is cardanol polyoxyethylene ether.

[0013] For example, the above-mentioned "5-8" can be 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, and other specific point values within this numerical range can also be selected, which will not be described here.

[0014] In the present application, the hydroxyl groups on the starch are activated under the catalysis of alkali, and then react with etherifying agent, so that carboxymethyl groups are introduced into the starch molecular chain. By introducing carboxyl groups into the molecular chain of amylose, firstly, the carboxyl group belongs to a hydrophilic group, which can increase the water solubility of amylose; secondly, the introduced carboxyl group has a steric hindrance effect, which reduces the hydrogen bond association of amylose, increases the sizing film toughness of amylose sizing, and improves its adhesion to pure cotton fibers, fully exploiting the advantages of amylose. And in this process, the addition of specific bio-based emulsifier can help the alkali and sodium chloroacetate to penetrate into the starch better, improve the reaction efficiency, and thus improve the stability and sizing film performance of the reaction product.

[0015] The modified starch bio-based sizing agent prepared in the application has a low gelatinization temperature, so it has good anti-caking properties. The modified starch molecular chain is easy to diffuse, which reduces the glass transition temperature of the starch, and the formed sizing film has excellent flexibility. Because the sizing agent has transparent, delicate, high viscosity, high adhesion, good emulsifying and permeability, and is not easy to spoil. In the textile industry, according to the principle of similarity and compatibility, the modified starch bio-based sizing agent has good adhesion to natural fibers. After etherification modification of starch, it can be used as a sizing material for high-branch high-density cotton and its blended fibers.

[0016] In one embodiment, the mass ratio of the starch, sodium chloroacetate and bio-based emulsifier is 1:(0.1-1):(0.005-0.02);

[0017] For example, the above "0.1-1" can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

[0018] The above "0.005-0.02" can be 0.005, 0.008, 0.01, 0.012, 0.015, 0.018, 0.02, etc. Other specific point values within the numerical range can also be selected, which will not be repeated here.

[0019] The molar ratio of the starch to the solute in the alkaline solution is 1:(0.8-2), for example, it can be 1:0.8, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.8, 1:2, etc. Other specific point values within the numerical range can also be selected, which will not be repeated here. It can be 1:(1-1.5).

[0020] In the application, when the raw material ratio is within the above specific range, the reaction efficiency is higher, the yield is high, and the modified product has more excellent sizing film performance.

[0021] In one embodiment, the starch includes any one or a combination of at least two of corn starch, wheat starch, cassava starch or potato starch.

[0022] In one embodiment, the alkaline solution includes a sodium hydroxide solution.

[0023] In one embodiment, the mass concentration of the sodium hydroxide solution is 28%-36%, for example, it can be 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, etc. Other specific point values within the numerical range can also be selected, which will not be repeated here.

[0024] In one embodiment, the mixture is further pre-dried.

[0025] In one embodiment, the pre-drying is performed at a temperature of 40-60℃, for example, 40℃, 42℃, 45℃, 48℃, 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here. Optionally, the temperature is 50-56℃.

[0026] In one embodiment, the pre-drying is performed to a moisture content of not more than 8%, for example, 8%, 7.8%, 7.5%, 7.2%, 7%, 6.8%, 6.6%, 6.5%, 6.2%, 5%, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here.

[0027] In one embodiment, the reaction is performed at a temperature of 120-170℃, for example, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here; and a time of 120-160min, for example, 120min, 122min, 125min, 128min, 130min, 135min, 140min, 145min, 150min, 155min, 160min, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here.

[0028] In one embodiment, the reaction is performed at a temperature of 150-160℃, for example, 150℃, 151℃, 152℃, 153℃, 154℃, 155℃, 156℃, 157℃, 158℃, 159℃, 160℃, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here; and a time of 130-150min, for example, 130min, 131min, 132min, 133min, 134min, 135min, 138min, 140min, 142min, 145min, 148min, 150min, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here.

[0029] In one embodiment, the pH is adjusted using a hydrochloric acid solution with a mass concentration of 1%-3%, for example, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, and the like, and other specific point values within the numerical range can be selected, which will not be repeated here.

[0030] In one embodiment, the washing solvent is water and / or ethanol.

[0031] In one embodiment, the washing is followed by drying and crushing and sieving.

[0032] In one embodiment, the drying temperature is 100-200℃, for example, it can be 100℃, 105℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, and other specific point values in the numerical range can be selected, which will not be repeated here.

[0033] In one embodiment, the drying time is 2-20h, for example, it can be 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, and other specific point values in the numerical range can be selected, which will not be repeated here.

[0034] In one embodiment, the drying is dried to a moisture content of not more than 10%, for example, it can be 10%, 9.8%, 9.5%, 9.2%, 9%, 8.8%, 8.6%, 8.5%, 8.2%, 8%, and other specific point values in the numerical range can be selected, which will not be repeated here.

[0035] In one embodiment, the mesh size of the crushing and sieving is not less than 100 mesh.

[0036] In a second aspect, the application provides a modified starch bio-based pulp, which is prepared by the preparation method of the first aspect.

[0037] In a third aspect, the application provides use of the modified starch bio-based pulp according to the second aspect in textiles.

[0038] Compared with the prior art, the application has the following beneficial effects:

[0039] In the present application, the hydroxyl groups on the starch are activated under the catalysis of alkali, and then react with an etherifying agent, so that carboxymethyl groups are introduced into the starch molecular chain. By introducing carboxyl groups into the molecular chain of amylose, firstly, the carboxyl groups belong to hydrophilic groups, which can increase the water solubility of amylose; secondly, the introduced carboxyl groups have steric hindrance effect, which reduces the hydrogen bond association of amylose, increases the toughness of the pulp film of amylose pulp, and improves the adhesion to pure cotton fibers, fully revealing the advantages of amylose. And in this process, a specific bio-based emulsifier is added, which can help the alkali and sodium chloroacetate penetrate into the starch better, improve the reaction efficiency, and thus improve the stability of the reaction product and the performance of the pulp film. And save energy, excellent mixing performance, very little block after reaction, very high yield, and better product performance.

[0040] Other aspects can be appreciated upon reading and understanding the detailed description. DETAILED DESCRIPTION

[0041] In order to further illustrate the technical means adopted by the present application and its effects, the technical solutions of the present application will be further described below in combination with the preferred embodiments of the present application, but the present application is not limited in the scope of the embodiments.

[0042] Example 1

[0043] The present embodiment provides a modified starch bio-based sizing agent, and its preparation method is as follows:

[0044] (1) Mix 100 g of corn starch (dry basis), a sodium hydroxide solution with a mass concentration of 32.5%, 50 g of sodium chloroacetate, and a cashew phenol polyoxyethylene ether NSS1305 solution with a mass concentration of 10% (solute mass is 1.5 g) after mixing, and then pre-dry, wherein the molar ratio of starch to solute in sodium hydroxide solution is 1:1.2. The pre-drying is drying at 55°C to a moisture content of 7%, and then reacting at 155°C for 140 min to obtain a reaction product.

[0045] (2) Adjust the pH of the obtained reaction product to 6.8 with 2% hydrochloric acid solution, filter, wash with deionized water, and centrifuge to obtain a precipitate, dry the precipitate at 180°C for 12h to obtain a solid with a water content of 8%, crush it through a 100 mesh sieve to obtain the modified starch bio-based sizing agent.

[0046] Example 2

[0047] The present embodiment provides a modified starch bio-based sizing agent, and its preparation method is as follows:

[0048] (1) 100 g of cassava starch (dry basis), a 35% by mass sodium hydroxide solution, 35 g of sodium chloroacetate, and a 7.5% by mass solution of cardanol polyoxyethylene ether NSS1305A (1 g of solute) were mixed and pre-dried, where the molar ratio of the starch to the solute in the sodium hydroxide solution was 1:1. The pre-drying was performed at 60°C until the water content was 6.5%, and then the reaction was performed at 160°C for 130 min to obtain a reaction product.

[0049] (2) The pH of the obtained reaction product was adjusted to 6.5 with a 3% hydrochloric acid solution, and the precipitate was obtained by centrifugation after washing with a 75% ethanol solution. The precipitate was dried at 150°C for 15 h to obtain a solid having a water content of 8.5%, which was pulverized and passed through a 100-mesh sieve to obtain the modified starch bio-based pulp.

[0050] Example 3

[0051] This example provides a modified starch bio-based pulp, the preparation method of which is as follows:

[0052] (1) 100 g of cassava starch (dry basis), a 35% by mass sodium hydroxide solution, 35 g of sodium chloroacetate, and a 7.5% by mass solution of cardanol polyoxyethylene ether NSS1305A (1 g of solute) were mixed and pre-dried, where the molar ratio of the starch to the solute in the sodium hydroxide solution was 1:1. The pre-drying was performed at 60°C until the water content was 6.5%, and then the reaction was performed at 160°C for 130 min to obtain a reaction product.

[0053] (2) The pH of the obtained reaction product was adjusted to 6.5 with a 3% hydrochloric acid solution, and the precipitate was obtained by centrifugation after washing with a 75% ethanol solution. The precipitate was dried at 150°C for 15 h to obtain a solid having a water content of 8.5%, which was pulverized and passed through a 100-mesh sieve to obtain the modified starch bio-based pulp.

[0054] Example 4

[0055] This example provides a modified starch bio-based pulp, which uses the corn starch in Example 1, and the difference between the preparation method thereof and that of Example 1 is only that the mass of the solute in the cardanol polyoxyethylene ether NSS1305A solution used is 0.1 g.

[0056] Example 5

[0057] This example provides a modified starch bio-based pulp, which uses the corn starch in Example 1, and the difference between the preparation method thereof and that of Example 1 is only that the molar ratio of the starch to the solute in the sodium hydroxide solution is 1:0.5.

[0058] Example 6

[0059] The present example provides a modified starch bio-based pulp, which uses the corn starch in Example 1, and the difference between the preparation method and Example 1 is only that the reaction in step (1) is carried out at 110°C for 140 min, and the subsequent step (2) is carried out after the reaction product is obtained, to obtain the modified starch bio-based pulp.

[0060] Comparative Example 1

[0061] The present comparative example provides a modified starch bio-based pulp, which uses the corn starch in Example 1, and the difference between the preparation method and Example 1 is only that no cardanol polyoxyethylene ether NSS1305 solution is added.

[0062] Test Example 1

[0063] The present test example tests the viscosity, pulp film performance and adhesion of the modified starch bio-based pulp prepared in Examples 1-6 and Comparative Example 1.

[0064] Pulp film performance: The modified starch bio-based pulp prepared in Examples 1-6 and Comparative Example 1 is configured into a 3% solution, and is water-bathed at 95°C for 1.5h. After the pulp solution is cooked, it is cooled to 50°C, and the film is poured at room temperature and naturally cooled to form the film. The pulp film is cut into uniform strips, with a length of more than 10 cm and a width of about 5 mm. The strips are placed in a constant temperature and humidity chamber for 24h. The thickness of each pulp film is measured (three thicknesses are measured for each pulp film, and the average is taken as the thickness of the pulp film). The YG028 universal material testing machine is used to test the pulp film performance of the sample (the sample is clamped at a distance of 100 mm, and the lowering speed is 500 mm / min). Each pulp film is tested 30 times, and the average value is calculated.

[0065] Adhesion performance: The modified starch bio-based pulp prepared in Examples 1-6 and Comparative Example 1, and the corn starch raw material in Example 1 are dissolved in water at a concentration of 1%, and are prepared into solutions, which are heated in a constant temperature water bath at 95°C and stirred uniformly. After 0.5h, the sizing is started. Pure cotton roving is lightly wound on a metal frame, and no external force is applied to the yarn during the winding process. The prepared samples are immersed in the cooked pulp solution, and the stopwatch is started. After 5 min (in order to make the sizing of the roving strips uniform, generally 2.5 min each), the frame is taken out and hung to dry naturally. The pure cotton and polyester cotton roving strips that have been dried are carefully cut and separated and placed in a self-sealing bag for testing. The YG028 universal material testing machine is used to test the adhesion performance of the sample, with a clamping distance of 50 mm and a stretching speed of 100 mm / min.

[0066] The prepared samples are immersed in the cooked pulp solution, and the stopwatch is started. After 5 min (in order to make the sizing of the roving strips uniform, generally 2.5 min each), the frame is taken out and hung to dry naturally. The pure cotton and polyester cotton roving strips that have been dried are carefully cut and separated and placed in a self-sealing bag for testing. The YG028 universal material testing machine is used to test the adhesion performance of the sample, with a clamping distance of 50 mm and a stretching speed of 100 mm / min.

[0067] The above test results are shown in Table 1.

[0068] Table 1

[0069] From the data in the table, it can be seen that:

[0070] (1) As can be seen from Examples 1 to 3, the modified starch bio-based sizing agent prepared by the preparation method provided in the application has excellent sizing film performance, strong breaking resistance, and high adhesion to pure cotton fibers, better meeting the sizing requirements of high-count high-density cotton and its blended fibers.

[0071] (2) As can be seen from the comparison between Example 1 and Example 4, when a specific amount of bio-based emulsifier is used, the modification reaction has higher efficiency, the yield is high, and the obtained bio-based sizing agent has more excellent sizing film performance.

[0072] (3) As can be seen from the comparison between Example 1 and Example 5, using a specific amount of alkaline solution as a catalyst can further improve the reaction speed, fully activate the hydroxyl groups on the starch molecules, improve the replacement efficiency with the modified functional groups, enhance the molecular chain activity, and improve the flexibility of the sizing film.

[0073] (4) As can be seen from the comparison between Example 1 and Example 6, the related modification reaction has higher reaction efficiency under a specific temperature range.

[0074] (5) As can be seen from the comparison between the examples and Comparative Example 1, adding a bio-based emulsifier during the reaction can help the alkaline solution and sodium chloroacetate penetrate better into the interior of the starch, so that the internal reaction mixture can be more uniformly mixed, and a modified starch bio-based sizing agent with high yield and uniformity is obtained.

[0075] In summary, in the present application, the hydroxyl groups on the starch are activated under the catalysis of alkali, and then react with the etherifying agent, so that carboxymethyl groups are introduced into the starch molecular chain. By introducing carboxyl groups into the molecular chain of amylose, first of all, the carboxyl group is a hydrophilic group, which can increase the water solubility of amylose; secondly, the introduced carboxyl group has a steric hindrance effect, which reduces the hydrogen bond association of amylose, increases the toughness of the sizing film of amylose sizing, and improves its adhesion to pure cotton fibers, fully exploiting the advantages of amylose. And in this process, adding a specific bio-based emulsifier can help the alkali and sodium chloroacetate penetrate better into the interior of the starch, improve the reaction efficiency, thereby improving the stability of the reaction product and the sizing film performance, saving energy, having excellent mixing performance, very little block-shaped material after reaction, extremely high yield, and more excellent product performance.

[0076] The applicant declares that the technical solutions of the present application are illustrated by the above-mentioned embodiments, but the present application is not limited to the above-mentioned embodiments, that is, the present application does not mean that it must rely on the above-mentioned embodiments to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of each raw material of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. fall within the protection scope and disclosure scope of the present application.

[0077] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above-mentioned embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application.

[0078] In addition, it should be noted that each specific technical feature described in the above-mentioned specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combination manners.

Claims

1. A method for preparing a modified starch bio-based pulp, comprising the following steps: mixing starch, a bio-based emulsifier, a basic solution and sodium chloroacetate, and then performing a reaction to obtain a reaction product, adjusting the pH of the reaction product to 5-8, and then filtering and washing to obtain the modified starch bio-based pulp; the bio-based emulsifier is cardanol polyoxyethylene ether.

2. The production method according to claim 1, wherein the mass ratio of the starch, the sodium chloroacetate and the bio-based emulsifier is 1: (0.1-1) : (0.005-0.02) ; the molar ratio of the starch to the solute in the basic solution is 1: (0.8-2), and further optionally 1: (1-1.5).

3. The production method according to claim 1, wherein, the starch comprises any one or a combination of at least two of corn starch, wheat starch, cassava starch or potato starch.

4. The production method according to claim 1, wherein the basic solution comprises a sodium hydroxide solution; optionally, the mass concentration of the sodium hydroxide solution is 28%-36%.

5. The production method according to claim 1, wherein the mixing is further followed by pre-drying; optionally, the temperature of the pre-drying is 40-60℃, and further optionally 50-56℃; optionally, the pre-drying is drying to a water content of not more than 8%.

6. The production method according to claim 1, wherein the temperature of the reaction is 120-170℃, and the time is 120-160min; optionally, the temperature of the reaction is 150-160℃, and the time is 130-150min.

7. The production method according to claim 1, wherein the pH is adjusted by using a hydrochloric acid solution with a mass concentration of 1%-3%.

8. The production method according to claim 1, wherein the solvent for the washing is water and / or ethanol; optionally, the washing is further followed by drying, crushing and sieving; optionally, the temperature of the drying is 100-200℃; optionally, the time of the drying is 2-20h; optionally, the drying is drying to a water content of not more than 10%; optionally, the mesh number of the sieve for the crushing and sieving is not less than 100 mesh. 9.A modified starch bio-based pulp prepared by the method according to any one of claims 1-8. 10.Use of the modified starch bio-based pulp according to claim 9 in textiles.

Images