Preparation method and device of high-performance modified starch

Abstract

The invention discloses a preparation method and device of high-performance modified starch, and the preparation method comprises the following steps: S1, adding starch and alcohol into a mixing and stirring device, and mixing to prepare starch slurry; s2, adding anhydrous sodium sulphate into the starch slurry, and adding an alkali solution to adjust the pH value of the starch slurry to 9.5-10; s3, adding epichlorohydrin into the mixing and stirring device, and stirring and reacting to obtain a cross-linked starch mixed solution; s4, adding a sodium hypochlorite solution, and reacting to obtain an oxidized starch mixed solution; s5, adding an acidic regulator in a stirring state to enable the pH value of the oxidized starch mixed solution to be 6.5-7.1, so as to obtain a high-performance modified starch mixed solution; s6, cooling to room temperature, discharging, and collecting the discharged material; and S6, carrying out freeze drying on the discharged material, washing the freeze-dried material by using absolute ethyl alcohol, drying, carrying out ball milling, sieving, and collecting sieved particles, thereby obtaining the high-performance modified starch. Alcohol is used as a solvent, so that the discharge amount of water can be reduced, and the pollution to the environment is further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of modified starch, and in particular to a preparation method and device for high-performance modified starch. Background Art

[0002] 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 and making it more suitable for certain application requirements. This kind of starch that has undergone secondary processing and changed its properties is collectively called modified starch. Starch is a carbohydrate formed by plants through photosynthesis. It has a wide range of sources, low prices, and returns to nature in the form of carbon dioxide and water after degradation. It is considered to be a natural and renewable material without pollution and has been widely studied and developed in non-food fields. Due to the shortcomings of starch such as insolubility in cold water, poor shear resistance, poor water resistance and lack of melt fluidity, it is difficult to use it alone as a polymer material. It needs to be chemically and physically modified to enhance certain functions or form new physical and chemical properties. At present, with the new modified starch raw materials, the application field of modified starch can be broadened and the development of modified starch can be promoted.

[0003] Currently, wet processing of modified starch is mostly used on the market. This process consumes a large amount of water resources, causing wastewater discharge to exceed the standard and polluting the environment. At the same time, the mixing of starch and chemical reagents is not sufficient, and the quality of the finished product is low. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a method and device for preparing high-performance modified starch, which uses alcohol as a solvent to reduce water discharge and thus reduce pollution to the environment; at the same time, epichlorohydrin is used for cross-linking and then oxidized with sodium hypochlorite to obtain a composite modified starch with high thermal stability, less viscosity reduction after heating for a long time, high paste transparency and good anti-agglomeration (aging) performance.

[0005] The technical solution provided by the present invention to solve the above problems is: a method for preparing high-performance modified starch, the preparation method comprising the following steps:

[0006] S1, adding starch and alcohol into a mixing and stirring device to prepare a starch slurry;

[0007] S2. Add sodium sulfate to the starch slurry, add an alkali solution to adjust the pH value of the starch slurry to 9.5-10, and stir for 1-2 hours;

[0008] S3, adding epichlorohydrin into the mixing and stirring device, stirring and reacting to obtain a cross-linked starch mixture;

[0009] S4, adding sodium hypochlorite solution, and indirectly adding alkaline solution to adjust the pH value of the solution, and obtaining an oxidized starch mixture after the reaction is completed;

[0010] S5. Adding an acidic regulator while stirring to adjust the pH value of the oxidized starch mixture to 6.5-7.1, and completing the neutralization reaction to obtain a high-performance modified starch mixture;

[0011] S6, cooling to room temperature, discharging, and collecting the discharged material;

[0012] S6. freeze-drying the output material, collecting the freeze-dried material, washing the freeze-dried material with anhydrous ethanol, drying, ball-milling, sieving, and collecting the sieved particles to obtain high-performance modified starch.

[0013] Preferably, the starch in S1 is any one of corn starch, tapioca starch, potato starch and waxy corn starch.

[0014] Preferably, the Baume degree of the starch slurry in S1 is controlled to be 20-28.

[0015] Preferably, the mass ratio of starch to alcohol in S1 is 2.1:1.2.

[0016] Preferably, the alkaline solution in S2 is a 10% NaOH solution.

[0017] Preferably, the stirring reaction time in S3 is 10-15h.

[0018] Preferably, the alkaline solution in S4 is a 10% NaOH solution.

[0019] Preferably, the acidic regulator in S5 is tyrosine.

[0020] Preferably, the mixing and stirring device in S1 comprises a mixing tank, a stirring assembly and a locking assembly;

[0021] The stirring assembly is installed on the mixing tank to stir the materials in the mixing tank;

[0022] The mixing tank is provided with a feed inlet, and an openable feed plate is installed in the feed inlet;

[0023] The locking assembly is used to lock the feed plate. When the stirring assembly drives the material in the mixing tank to stir, the locking assembly opens the lock on the feed plate. When the stirring assembly stops stirring, the locking assembly releases the lock on the feed plate.

[0024] Preferably, the stirring assembly includes a stirring motor, a stirring shaft and a plurality of stirring paddles. The stirring motor is installed at the upper end of the mixing tank. One end of the stirring shaft is connected to the output end of the stirring motor and the other end extends into the interior of the mixing tank. The plurality of stirring paddles are installed on the stirring shaft.

[0025] Compared with the prior art, the advantages of the present invention are as follows: the present invention uses alcohol as a solvent, which can reduce water discharge and thus reduce environmental pollution; at the same time, epichlorohydrin is cross-linked and then oxidized with sodium hypochlorite to obtain a composite modified starch with high thermal stability, less viscosity reduction after heating for a long time, high paste transparency, and good anti-agglomeration (aging) performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] Figure 1 It is a flowchart of the preparation method of the present invention;

[0028] Figure 2 It is a schematic diagram of the three-dimensional structure of the mixing and stirring of the present invention;

[0029] Figure 3 is a cross-sectional view of the mixing and stirring of the present invention;

[0030] Figure 4 yes Figure 3 The enlarged schematic diagram of point A in the middle;

[0031] Figure 5 is a schematic diagram of the installation sleeve;

[0032] Figure 6 It is a top view of the follower frame and the lower connecting ring.

[0033] The attached drawings are marked with: 1. mixing tank, 2. stirring motor, 3. feed plate, 4. locking rod, 5. feed port, 6. bayonet, 7. connecting rod, 8. driving rod, 9. stirring paddle, 10. stirring shaft, 11. spring three, 12. driving ring, 13. guide rod, 14. lifting ring, 15. mounting sleeve, 16. upper connecting ring, 17. spring two, 18. lower connecting ring, 19. bearing, 20. guide column, 21. guide groove, 22. spring one. DETAILED DESCRIPTION

[0034] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0035] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present invention.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the definition of "first" and "second" features can explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "several" is two or more, unless otherwise clearly and specifically defined.

[0037] In the present invention, unless otherwise specified and limited, the terms "assemble", "connect", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection; it can be directly connected, or it can be connected through an intermediate medium, or the two elements can be internally connected. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0039] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0040] Example 1

[0041] A method for preparing high-performance modified starch, the method comprising the following steps:

[0042] S1, adding starch and alcohol (mass ratio of starch to alcohol is 2.1:1.2) into a mixing and stirring device to prepare a starch slurry, and controlling the Baume degree of the starch slurry to be 20-28;

[0043] S2. Add sodium sulfate to the starch slurry, add 10% NaOH solution to adjust the pH value of the starch slurry to 9.5-10, and stir for 1-2 hours;

[0044] S3, add epichlorohydrin into the mixing and stirring device, and stir for reaction (time is 10-15h) to obtain a cross-linked starch mixture;

[0045] S4, adding sodium hypochlorite solution, and indirectly adding 10% NaOH solution to adjust the pH value of the solution, and obtaining an oxidized starch mixture after the reaction is completed;

[0046] S5. Add tyrosine while stirring to make the pH value of the oxidized starch mixture 6.5-7.1, and the neutralization reaction is completed to obtain a high-performance modified starch mixture;

[0047] S6, cooling to room temperature, discharging, and collecting the discharged material;

[0048] S6. freeze-drying the output material, collecting the freeze-dried material, washing the freeze-dried material with anhydrous ethanol, drying, ball-milling, sieving, and collecting the sieved particles to obtain high-performance modified starch.

[0049] Specifically, the starch in S1 is any one of corn starch, tapioca starch, potato starch and waxy corn starch.

[0050] In the above scheme, using alcohol as a solvent can reduce water emissions and thus reduce environmental pollution; at the same time, epichlorohydrin is used for cross-linking and then oxidized with sodium hypochlorite to obtain a composite modified starch with high thermal stability, less viscosity reduction after heating for a long time, high paste transparency, and good anti-sedimentation (aging) performance.

[0051] Example 2

[0052] This embodiment discloses a mixing and stirring device, which is used in S1 in Embodiment 1. Specifically, the mixing and stirring device includes a mixing tank, a stirring assembly, and a locking assembly;

[0053] The stirring assembly is installed on the mixing tank to stir the materials in the mixing tank;

[0054] The mixing tank is provided with a feed inlet, and an openable feed plate is installed in the feed inlet;

[0055] The locking assembly is used to lock the feed plate. When the stirring assembly drives the material in the mixing tank to stir, the locking assembly opens the lock on the feed plate. When the stirring assembly stops stirring, the locking assembly releases the lock on the feed plate.

[0056] In this embodiment, specifically, the stirring assembly includes a stirring motor, a stirring shaft and a plurality of stirring paddles. The stirring motor is installed at the upper end of the mixing tank. One end of the stirring shaft is connected to the output end of the stirring motor, and the other end extends into the interior of the mixing tank. The plurality of stirring paddles are installed on the stirring shaft.

[0057] Furthermore, the locking assembly includes a follower frame, a rotating ring, a mounting sleeve 15, a lifting ring 14 and a locking rod 4, wherein the mounting sleeve 15 is vertically arranged on the inner wall of the upper cover of the mixing tank 1, and the lifting ring 14 and the rotating ring are sequentially mounted on the mounting sleeve 15 from top to bottom, and a spiral upward guide groove 21 is arranged around the outer circumference of the mounting sleeve 15, and a guide column 20 matching the guide groove 21 is arranged on the inner ring of the rotating ring, and the rotating ring is fixedly connected to the center position of the follower frame, and the lifting ring 14 and the rotating ring are arranged on the inner wall of the upper cover of the mixing tank 1. A guide rod 13 is provided, and a guide hole cooperating with the guide rod 13 is provided on the lifting ring 14. A spring 22 is mounted on the mounting sleeve 15. One end of the spring 22 abuts against the inner wall of the upper cover of the mixing tank 1, and the other end abuts against the upper end surface of the lifting ring 14. The locking rod 4 is fixedly connected to the side end surface of the lifting ring 14. A slot cooperating with the feed plate 3 is installed at the feed port 5. The feed plate 3 can slide in the feed port 5 along the slot, and the lower end surface of the feed plate 3 is provided with a slot 23 that can engage with the locking rod 4.

[0058] Specifically, the follower frame includes a plurality of connecting rods and a plurality of driving rods, wherein the plurality of connecting rods are radially mounted on the outer circumference of the rotating ring, the driving rods are vertically arranged at one end of the connecting rods away from the rotating ring, and one side of the driving rods is arranged close to the inner wall of the mixing tank. In this solution, on the one hand, the follower frame rotates with the material at the beginning of stirring, thereby driving the locking assembly to lock the feed plate, and on the other hand, the driving rods in the follower frame are arranged close to the inner wall of the mixing tank, and the material will collide with the driving rods during the stirring process, thereby improving the stirring effect at the inner wall of the mixing tank, and can effectively reduce the material from adhering to the inner wall of the mixing tank.

[0059] Among them, a horizontal positioning groove is also arranged on the mounting sleeve, and the horizontal positioning groove is connected to the upper end of the guide groove. A spring three is arranged in the horizontal positioning groove. When the follower ring rotates, it drives the rotating ring to rotate. During the rotation of the rotating ring, the guide column enters into the horizontal positioning groove from the guide groove and squeezes the spring three in the horizontal positioning groove. When the follower ring stops rotating, the guide column is separated from the horizontal positioning groove and enters into the guide groove under the action of the spring three.

[0060] Furthermore, in order to improve the stability of the stirring shaft during rotation, a mounting groove is provided on the inner ring of the mounting sleeve, a bearing is installed in the mounting groove, and the inner ring of the bearing cooperates with the stirring shaft.

[0061] Those skilled in the art will know that the materials in the mixing tank will be stirred along with the stirring shaft during the stirring process. If the staff opens the discharge plate on the mixing tank during the operation of the stirring assembly, the materials in the mixing tank may splash out, and some external impurities may easily enter the mixing tank through the feed port and affect the materials in the mixing tank. Therefore, in the above technical scheme, when the stirring motor drives the stirring shaft to rotate, the stirring paddle drives the materials to move along the rotation direction of the stirring shaft. During the movement of the materials, the driving plate is driven to rotate along with the materials, thereby driving the rotating ring to rotate. During the rotation of the rotating ring, the guide column is driven to move along the guide groove The lifting ring then drives the locking rod to disengage from the bayonet during the downward movement of the lifting ring, and the feed plate cannot move horizontally along the slot. Therefore, the feed port is locked. When the material reaction is completed, the stirring assembly stops working, and the material in the mixing tank is in a stationary state. The guide column disengages from the horizontal positioning slot and enters the guide slot under the action of spring three. At the same time, spring one drives the lifting ring downward, and the rotating ring moves downward under the action of the follower frame, its own gravity and the elastic force of spring one. During the downward movement of the lifting ring, the locking rod is disengaged from the bayonet, and the feed plate can be opened normally.

[0062] It should be noted that in the process of production, it is sometimes necessary to add materials into the mixing tank midway, therefore, a lock release assembly is also included, the lock release assembly includes a drive ring, the upper cover of the mixing tank is provided with an annular mounting groove for installing the drive ring, the lower end of the drive ring is abutted against the upper end of the lifting ring, the rotating ring includes a lower connecting ring, an upper connecting ring and a spring 2, one end of the spring 2 is connected to the upper connecting ring, and the other end is connected to the lower connecting ring, and the guide column is provided on the lower connecting ring. When it is necessary to open the feed plate midway, a special tool can be used to press down on the drive ring, and the process of pressing down the drive ring drives the lifting ring to compress the spring 2 downward, the locking rod can be disengaged from the bayonet, and the feed plate can be opened normally. This solution can ensure that the stirring assembly can work normally during the process of opening the feed plate, thereby improving the working efficiency of the stirring assembly.

[0063] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. All changes made within the scope of protection of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing high-performance modified starch, characterized in that: The preparation method comprises the following steps: S1, adding starch and alcohol into a mixing and stirring device to prepare a starch slurry; S2. Add sodium sulfate to the starch slurry, add an alkali solution to adjust the pH value of the starch slurry to 9.5-10, and stir for 1-2 hours; S3, adding epichlorohydrin into the mixing and stirring device, stirring and reacting to obtain a cross-linked starch mixture; S4, adding sodium hypochlorite solution, and indirectly adding alkaline solution to adjust the pH value of the solution, and obtaining an oxidized starch mixture after the reaction is completed; S5. Adding an acidic regulator while stirring to adjust the pH value of the oxidized starch mixture to 6.5-7.1, and completing the neutralization reaction to obtain a high-performance modified starch mixture; S6, cooling to room temperature, discharging, and collecting the discharged material; S7. freeze-drying the output material, collecting the freeze-dried material, washing the freeze-dried material with anhydrous ethanol, drying, ball-milling, sieving, and collecting the sieved particles to obtain high-performance modified starch.

2. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The starch in S1 is any one of corn starch, tapioca starch, potato starch and waxy corn starch.

3. The method for preparing a high-performance modified starch according to claim 1, characterized in that: In the S1, the Baume degree of the starch slurry is controlled to be 20-28.

4. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The mass ratio of starch to alcohol in S1 is 2.1:1.

2.

5. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The alkaline solution in S2 is a 10% NaOH solution.

6. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The stirring reaction time in S3 is 10-15h.

7. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The alkaline solution in S4 is a 10% NaOH solution.

8. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The acidic regulator in S5 is tyrosine.

9. The method for preparing a high-performance modified starch according to claim 1, characterized in that: The mixing and stirring device in S1 comprises a mixing tank, a stirring assembly and a locking assembly; The stirring assembly is installed on the mixing tank to stir the materials in the mixing tank; The mixing tank is provided with a feed inlet, and an openable feed plate is installed in the feed inlet; The locking assembly is used to lock the feed plate. When the stirring assembly drives the material in the mixing tank to stir, the locking assembly opens the lock on the feed plate. When the stirring assembly stops stirring, the locking assembly releases the lock on the feed plate.

10. The method for preparing a high-performance modified starch according to claim 9, characterized in that: The stirring assembly includes a stirring motor, a stirring shaft and a plurality of stirring paddles. The stirring motor is installed at the upper end of the mixing tank. One end of the stirring shaft is connected to the output end of the stirring motor and the other end extends into the mixing tank. The plurality of stirring paddles are installed on the stirring shaft.

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