Preparation method of modified starch bio-based slurry as well as product and application of modified starch bio-based slurry

Abstract

The invention relates to a preparation method of modified starch bio-based slurry as well as a product and application thereof, the preparation method comprises the following steps: mixing starch, a bio-based emulsifier, an alkaline solution and sodium chloroacetate, reacting to obtain a reactant, adjusting the pH value of the reactant to 5-8, and filtering and washing to obtain the modified starch bio-based slurry, the bio-based emulsifier is cardanol polyoxyethylene ether. Hydroxyl on starch is activated under the catalytic action of alkali and then reacts with an etherifying agent, so that carboxymethyl groups are introduced to a starch molecular chain, a specific bio-based emulsifier is added in the process, alkali and sodium chloroacetate can be helped to better permeate into the starch, the reaction efficiency is improved, and the stability of the starch is improved. Therefore, the stability and serous membrane performance of a reaction product are improved.

Description

Technical Field

[0001] The invention belongs to the field of textiles, and specifically relates to a preparation method of a modified starch bio-based slurry and a product and application thereof. Background Art

[0002] The warp yarn is repeatedly stretched and bent more than 4,000 times from the back beam of the loom to the weaving mouth; the friction between the warp yarns, as well as the friction between the warp yarns and the eyelets, shuttle plates, and weft insertion devices are quite intense, all exceeding the wear resistance of the original yarns sized in the weft. In order to reduce the breakage rate of the warp yarn, improve the weavability of the warp yarn and the product quality, the warp yarn must be given higher wear resistance, the hairiness on the surface of the yarn must be flattened, the warp yarn strength must be appropriately increased, and the original elasticity of the warp yarn must be preserved as much as possible. Therefore, sizing is a key process in the preparation of the warp yarn before weaving.

[0003] Starch is the main sizing material for sizing yarn and has a long history. Starch is widely available, cheap and has good biodegradability. At present, starch sizing accounts for 70% of all textile sizing materials. The advantages of starch sizing are good adhesion to cellulose fibers, film-forming properties, extremely high breaking strength and elongation at break, fatigue resistance and other excellent sizing properties. However, starch sizing has poor adhesion to high-count and high-density cotton fibers, poor hairiness conformability, a lot of falling objects, and a high yarn breakage rate, which seriously affects the weaving efficiency of the yarn.

[0004] Starch is composed of two parts: amylose and amylopectin. Amylose is a linear macromolecule formed by dehydrated glucose units connected by α-1,4 glycosidic bonds. The molecular weight of amylose is much smaller than that of amylopectin, and amylose has good water solubility in hot water. The slurry viscosity of amylose is small and the permeability is strong, but amylose is easy to age and regenerate, which is not conducive to the permeability and film-forming properties of amylose, limiting its application in textile slurry. In order to improve the performance of starch and expand its application range, physical, chemical or enzymatic treatment is used to introduce new functional groups into starch molecules or change the size of starch molecules and the properties of starch particles, thereby changing the natural properties of starch, such as gelatinization temperature, thermal viscosity and its stability, freeze-thaw stability, gel strength, film-forming property, transparency, etc., making it more suitable for certain application requirements.

[0005] There are two main types of starch modification in the prior art, one is the dry method and the other is the wet method. The wet method is complex, time-consuming and energy-intensive. The dry method is simple and time-saving, but because no water is added or too little water is added during the preparation process, the chemical reagents and starch are not mixed evenly, the reaction is not sufficient, it is easy to agglomerate, and the product yield is unstable. Therefore, it is of great significance to provide a starch modification method with excellent film properties and high product stability. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing a modified starch bio-based slurry, a product thereof and applications thereof, and in particular to provide a method for preparing a modified starch bio-based slurry, a product thereof and applications thereof in textiles.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing a modified starch bio-based slurry, the preparation method comprising the following steps:

[0009] The starch, the bio-based emulsifier, the alkaline solution and the sodium chloroacetate are mixed and reacted to obtain a reactant, and the pH of the reactant is adjusted to 5-8, and then filtered and washed to obtain the modified starch bio-based slurry;

[0010] The bio-based emulsifier is cardanol polyoxyethylene ether.

[0011] Among them, the above-mentioned "5-8" can be, for example, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, etc. Other specific point values ​​within this numerical range can be selected, and they will not be elaborated here one by one.

[0012] In the present invention, the hydroxyl groups on the starch are activated under the catalytic action of the base, and then react with the etherifying agent, so that the carboxylmethyl groups are introduced into the starch molecular chain. By introducing the carboxyl group into the molecular chain of amylose, firstly, the carboxyl group belongs to the hydrophilic group, which can increase the water solubility of amylose; secondly, the introduced carboxyl group has a steric hindrance effect, which reduces the association of hydrogen bonds of amylose, increases the toughness of the amylose film, and improves its adhesion to pure cotton fibers, fully volatilizing the advantages of amylose. And adding a specific bio-based emulsifier in this process can help alkali and sodium chloroacetate to better penetrate into the starch, improve the reaction efficiency, and thus improve the stability and film properties of the reaction product.

[0013] The modified starch bio-based slurry prepared by the present invention has a reduced gelatinization temperature, so that it has good anti-coagulation properties. The modified starch molecular chains are easy to diffuse, which reduces the glass transition temperature of the starch, and the formed slurry film has excellent flexibility. Since the slurry of the modified starch bio-based slurry is transparent, delicate, has high viscosity, has large adhesion, and has good emulsification and permeability, it is not easy to spoil and deteriorate. In the textile industry, based on the principle of similar compatibility, the modified starch bio-based slurry has good adhesion to natural fibers. After the starch is etherified and modified by the present invention, it can be used as a sizing raw material for high-count and high-density cotton and its blended fibers.

[0014] Preferably, the mass ratio of the starch, sodium chloroacetate and bio-based emulsifier is 1:(0.1-1):(0.005-0.02);

[0015] The above “0.1-1” may be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.;

[0016] The above-mentioned "0.005-0.02" can be, for example, 0.005, 0.008, 0.01, 0.012, 0.015, 0.018, 0.02, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0017] The molar ratio of 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 values ​​within this numerical range can be selected and will not be described one by one here. Preferably, it is 1:(1-1.5).

[0018] In the present invention, when the raw material ratio is within the above specific range, the reaction efficiency is higher, the yield is high and the obtained modified product has more excellent slurry film performance.

[0019] Preferably, the starch comprises any one of corn starch, wheat starch, tapioca starch or potato starch, or a combination of at least two thereof.

[0020] Preferably, the alkaline solution comprises sodium hydroxide solution.

[0021] Preferably, 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 this numerical range can be selected, which will not be described here one by one.

[0022] Preferably, the mixing is followed by pre-drying.

[0023] Preferably, the pre-drying temperature is 40-60°C, for example, it can be 40°C, 42°C, 45°C, 48°C, 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, etc. Other specific point values ​​within this numerical range can be selected and will not be described one by one here. It is preferably 50-56°C.

[0024] Preferably, the pre-drying is drying to a moisture content of no more than 8%, for example, it can be 8%, 7.8%, 7.5%, 7.2%, 7%, 6.8%, 6.6%, 6.5%, 6.2%, 5%, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0025] Preferably, the reaction temperature is 120-170°C, for example, it can be 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, etc., and other specific point values ​​within the numerical range can be selected, which will not be described one by one here; the reaction time is 120-160min, for example, it can be 120min, 122min, 125min, 128min, 130min, 135min, 140min, 145min, 150min, 155min, 160min, etc., and other specific point values ​​within the numerical range can be selected, which will not be described one by one here.

[0026] Preferably, the reaction temperature is 150-160°C, for example, it can be 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 157°C, 158°C, 159°C, 160°C, etc., and other specific point values ​​within the numerical range can be selected, which will not be described one by one here; the reaction time is 130-150min, for example, it can be 130min, 131min, 132min, 133min, 134min, 135min, 138min, 140min, 142min, 145min, 148min, 150min, etc., and other specific point values ​​within the numerical range can be selected, which will not be described one by one here.

[0027] Preferably, the pH is adjusted using a hydrochloric acid solution with a mass concentration of 1%-3%, for example, it can be 1%, 1.2%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.8%, 3%, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0028] Preferably, the washing solvent is water and / or ethanol.

[0029] Preferably, the washing is followed by drying, crushing and screening.

[0030] Preferably, the drying temperature is 100-200°C, for example, it can be 100°C, 105°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described here one by one.

[0031] Preferably, the drying time is 2-20 h, for example, it can be 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0032] Preferably, the drying is to dry to a moisture content of no 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%, etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0033] Preferably, the mesh size of the crushed and screened product is not less than 100 meshes.

[0034] In a second aspect, the present invention provides a modified starch bio-based slurry, wherein the modified starch bio-based slurry is prepared by the preparation method described in the first aspect.

[0035] In a third aspect, the present invention provides a use of the modified starch bio-based slurry according to the second aspect in textiles.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] In the present invention, the hydroxyl groups on the starch are activated under the catalytic action of the base, and then react with the etherifying agent, so that the carboxylmethyl group is introduced into the starch molecular chain. By introducing the carboxyl group 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 association of hydrogen bonds of amylose, increases the toughness of the amylose film of amylose slurry, and improves its adhesion to pure cotton fiber, fully volatilizing the advantages of amylose. And adding a specific bio-based emulsifier in this process can help alkali and sodium chloroacetate to better penetrate into the starch, improve the reaction efficiency, thereby improving the stability and membrane performance of the reaction product, and saving energy, excellent mixing performance, very few lumps after the reaction, extremely high yield rate, and better product performance. DETAILED DESCRIPTION

[0038] In order to further explain the technical means and effects adopted by the present invention, the technical solution of the present invention is further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0039] Example 1

[0040] This embodiment provides a modified starch bio-based slurry, and the preparation method thereof is as follows:

[0041] (1) 100 g corn starch (dry basis), a sodium hydroxide solution with a mass concentration of 32.5%, 50 g sodium chloroacetate and a 10% cardanol polyoxyethylene ether NSS1305 solution (solute mass of 1.5 g) were mixed and pre-dried, wherein the molar ratio of the starch to the solute in the sodium hydroxide solution was 1:1.2. The pre-drying was performed by drying at 55° C. to a water content of 7%, and then reacting at 155° C. for 140 min to obtain a reactant.

[0042] (2) The pH of the obtained reactant is adjusted to 6.8 with a 2% hydrochloric acid solution, filtered, washed with deionized water, and centrifuged to obtain a precipitate, the precipitate is dried at 180° C. for 12 hours to obtain a solid with a moisture content of 8%, and the solid is crushed and passed through a 100-mesh sieve to obtain the modified starch bio-based slurry.

[0043] Example 2

[0044] This embodiment provides a modified starch bio-based slurry, and the preparation method thereof is as follows:

[0045] (1) 100 g of wheat starch (dry basis), a sodium hydroxide solution with a mass concentration of 30%, 30 g of sodium chloroacetate and a 5% cardanol polyoxyethylene ether NSS1308 solution (solute mass of 2 g) were mixed and pre-dried, wherein the molar ratio of starch to the solute in the sodium hydroxide solution was 1:1.5. The pre-drying was performed by drying at 48° C. to a water content of 7.8%, and then reacting at 150° C. for 150 min to obtain a reactant.

[0046] (2) The pH value of the obtained reactant is adjusted to 7 with 1% hydrochloric acid solution, filtered, washed with anhydrous ethanol and centrifuged to obtain a precipitate, the precipitate is dried at 200° C. for 10 hours to obtain a solid with a moisture content of 7%, and the solid is crushed and passed through a 100-mesh sieve to obtain the modified starch bio-based slurry.

[0047] Example 3

[0048] This embodiment provides a modified starch bio-based slurry, and the preparation method thereof is as follows:

[0049] (1) 100 g of cassava starch (dry basis), a sodium hydroxide solution with a mass concentration of 35%, 35 g of sodium chloroacetate and a cardanol polyoxyethylene ether NSS1305A solution with a mass concentration of 7.5% (solute mass of 1 g) were mixed and pre-dried, wherein the molar ratio of starch to the solute in the sodium hydroxide solution was 1:1. The pre-drying was performed by drying at 60° C. to a water content of 6.5%, and then reacting at 160° C. for 130 min to obtain a reactant.

[0050] (2) The pH value of the obtained reactant is adjusted to 6.5 with a 3% hydrochloric acid solution, filtered, washed with a 75% ethanol solution, and centrifuged to obtain a precipitate, the precipitate is dried at 150° C. for 15 hours to obtain a solid with a moisture content of 8.5%, and the solid is crushed and passed through a 100-mesh sieve to obtain the modified starch bio-based slurry.

[0051] Example 4

[0052] This embodiment provides a modified starch bio-based slurry, which uses the corn starch in Example 1. The preparation method thereof is different from that in Example 1 only in that the mass of the solute in the cardanol polyoxyethylene ether NSS1305A solution used is 0.1 g.

[0053] Example 5

[0054] This embodiment provides a modified starch bio-based slurry, using the corn starch in Example 1, and the preparation method thereof is different from that in Example 1 only in that the molar ratio of the starch to the solute in the sodium hydroxide solution is 1:0.5.

[0055] Example 6

[0056] This embodiment provides a modified starch bio-based slurry, which uses the corn starch in Example 1. The preparation method thereof is different from that in Example 1 only in that in step (1), the reaction is carried out at 110° C. for 140 minutes, and after obtaining the reactant, the subsequent step (2) is carried out to obtain the modified starch bio-based slurry.

[0057] Comparative Example 1

[0058] This comparative example provides a modified starch bio-based slurry, which uses the corn starch in Example 1. The preparation method thereof is different from that in Example 1 only in that the cardanol polyoxyethylene ether NSS1305 solution is not added.

[0059] Test Example 1

[0060] This test example tests the viscosity, film performance and adhesion of the modified starch bio-based slurry prepared in Examples 1-6 and Comparative Example 1.

[0061] Film performance: The modified starch bio-based slurry prepared in Examples 1-6 and Comparative Example 1 is prepared into a 3% solution, and boiled in a water bath at 95°C for 1.5 hours; after the slurry is boiled, it is cooled to 50°C, poured into a film at room temperature, and naturally cooled until the film is formed; the film is cut into uniform strips, ensuring that the length is greater than 10cm and the width is about 5mm. Place it in a constant temperature and humidity room for equilibration for 24 hours; use a vernier caliper to measure the thickness of each film (measure the thickness of each film at three locations, and take the average value as the film thickness). The film performance of the sample is tested on a YG028 universal material testing machine (sample clamping distance 100mm, descent speed 500mm / min). Each film is tested 30 times, and the average value is calculated.

[0062] Adhesion performance: The modified starch bio-based slurry prepared in Examples 1-6 and Comparative Example 1 and the corn starch raw material in Example 1 were dissolved in water at a concentration of 1% to prepare solutions, which were heated in a constant temperature water bath at 95°C and stirred evenly. After 0.5 hours, sizing began; pure cotton roving was selected and gently wound on a metal frame. No external force was applied to the yarn during the winding process, and the yarn was set aside. At least 30 rovings were tested each time.

[0063] Immerse the prepared sample in the cooked slurry, press the stopwatch to time, and immerse for 5 minutes (in order to make the roving strips sizing evenly, generally immerse for 2.5 minutes each in the forward and reverse directions), then take out the frame, hang it to dry naturally, and keep the roving strips level during the drying process; carefully cut the dried pure cotton and polyester-cotton roving strips, and separately put them in self-sealing bags for testing. The present invention uses a YG028 universal material testing machine to test the adhesion performance of the sample, with a clamping distance of 50 mm and a tensile speed of 100 mm / min.

[0064] The above test results are shown in Table 1.

[0065] Table 1

[0066]

[0067] From the data in the table, we can see that:

[0068] (1) It can be seen from Examples 1 to 3 that the modified starch bio-based slurry prepared by the preparation method provided by the present invention has excellent slurry film performance, strong anti-fracture performance, and high adhesion to pure cotton fibers, which better meets the sizing requirements of high-count and high-density cotton and its blended fibers.

[0069] (2) By comparing Example 1 with Example 4, it can be seen that when a specific amount of bio-based emulsifier is used, the modification reaction is more efficient, the yield is high, and the obtained bio-based slurry has better slurry film properties.

[0070] (3) By comparing Example 1 with Example 5, it can be seen that using a specific amount of alkaline solution as a catalyst can further increase the reaction rate, fully activate the hydroxyl groups on the starch molecules, improve the replacement efficiency with the modified functional groups, enhance the activity of the molecular chains, and improve the flexibility of the plasma membrane.

[0071] (4) By comparing Example 1 with Example 6, it can be seen that when the relevant modification reaction is carried out within a specific temperature range, it has a higher reaction efficiency.

[0072] (5) By comparing the embodiment with comparative example 1, it can be seen that adding a bio-based emulsifier during the reaction process can help the alkaline solution and sodium chloroacetate to better penetrate into the interior of the starch, so that the reactants can be mixed more evenly, thereby obtaining a uniform and high-yield modified starch bio-based slurry.

[0073] In summary, in the present invention, the hydroxyl groups on the starch are activated under the catalytic action of the base, and then react with the etherifying agent, so that the carboxyl group is introduced into the starch molecular chain. By introducing the carboxyl group 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 association of hydrogen bonds of amylose, increases the toughness of the amylose film of amylose slurry, and improves its adhesion to pure cotton fiber, fully volatilizing the advantages of amylose. And adding a specific bio-based emulsifier in this process can help alkali and sodium chloroacetate to better penetrate into the interior of the starch, improve the reaction efficiency, thereby improving the stability and membrane performance of the reaction product, and saving energy, excellent mixing performance, very few lumps after the reaction, extremely high yield rate, and better product performance.

[0074] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0075] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0076] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for preparing a modified starch bio-based slurry, characterized in that: The preparation method comprises the following steps: The starch, the bio-based emulsifier, the alkaline solution and the sodium chloroacetate are mixed and reacted to obtain a reactant, and the pH of the reactant is adjusted to 5-8, and then filtered and washed to obtain the modified starch bio-based slurry; The bio-based emulsifier is cardanol polyoxyethylene ether.

2. The preparation method according to claim 1, characterized in that: The mass ratio of the starch, sodium chloroacetate and bio-based emulsifier is 1:(0.1-1):(0.005-0.02); The molar ratio of the starch to the solute in the alkaline solution is 1:(0.8-2), preferably 1:(1-1.5).

3. The preparation method according to claim 1, characterized in that: The starch includes any one of corn starch, wheat starch, tapioca starch or potato starch, or a combination of at least two of them.

4. The preparation method according to claim 1, characterized in that: The alkaline solution includes a sodium hydroxide solution; Preferably, the mass concentration of the sodium hydroxide solution is 28%-36%.

5. The preparation method according to claim 1, characterized in that: Pre-drying is also performed after the mixing; Preferably, the pre-drying temperature is 40-60°C, preferably 50-56°C; Preferably, the pre-drying is drying to a moisture content of no more than 8%.

6. The preparation method according to claim 1, characterized in that: The reaction temperature is 120-170°C and the reaction time is 120-160min; Preferably, the reaction temperature is 150-160° C. and the reaction time is 130-150 min.

7. The preparation method according to claim 1, characterized in that: The pH is adjusted by using a hydrochloric acid solution with a mass concentration of 1%-3%.

8. The preparation method according to claim 1, characterized in that: The washing solvent is water and / or ethanol; Preferably, the washing is followed by drying, crushing and screening; Preferably, the drying temperature is 100-200°C; Preferably, the drying time is 2-20 hours; Preferably, the drying is drying to a moisture content of no more than 10%; Preferably, the mesh size of the crushed and screened product is not less than 100 meshes.

9. A modified starch bio-based slurry, characterized in that: The modified starch bio-based slurry is prepared by the preparation method according to any one of claims 1-8.

10. Use of the modified starch bio-based slurry according to claim 9 in textiles.

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