WO2022045483A1 - Eco-friendly thermoplastic starch and preparation method therefor - Google Patents

Abstract

The present invention relates to a method for preparing an eco-friendly thermoplastic starch by using natural materials. The eco-friendly thermoplastic starch according to the present invention is prepared as an eco-friendly thermoplastic starch in uniform and fine powder state by mixing a starch, which is obtained from a plant through extraction, with honey having plasticity and lemon juice having a crosslinking property, and then passing same through a manual operation and a ball-mill process. The present invention can prepare a thermoplastic starch at low cost by using natural materials such as honey and lemon, which are readily available, and using an eco-friendly process, and also can prepare a thermoplastic starch which is eco-friendly and has excellent physical properties and strength.

Description

Eco-friendly thermoplastic starch and its manufacturing method

The present invention relates to thermoplastic starch, and more particularly, to a method for producing eco-friendly thermoplastic starch using a natural material.

In general, thermoplastic starch (thermoplastic starch, TPS) refers to starch having a property of being softened and easily deformed when heated, and hardened again when cooled.

Such thermoplastic starch is prepared by mixing a plasticizer and starch, and is used as a raw material in the process of manufacturing plastic moldings, polymer composite materials, and packaging materials.

In the related art, Korean Patent Registration No. 10-1249407, Korean Patent Registration No. 10-0150694, and the like are disclosed.

The prior art described above relates to a technology for preparing a thermoplastic starch by mixing starch and a plasticizer, and for preparing a thermoplastic starch having excellent biodegradability and excellent components and properties.

These conventional techniques are prepared by adding chemicals such as polyvinyl alcohol, distearate, ethylene, and the like when manufacturing thermoplastic starch.

Accordingly, there is a disadvantage that it is difficult to obtain additional materials when manufacturing thermoplastic starch based on the contents of the prior art described above, and it may take some time.

In addition, since these materials are known as chemically toxic substances, there is a concern that harmful substances and toxic components are highly likely to be discharged in the process of manufacturing the thermoplastic starch to which the materials are added, which may cause environmental problems.

In addition, although the material to be manufactured is an eco-friendly material, there is also a problem that the material used for manufacturing is not eco-friendly.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above, and an object of the present invention is to prepare an eco-friendly thermoplastic starch using a natural material.

Another object of the present invention is to prepare a thermoplastic starch having excellent properties and strength while being eco-friendly by mixing honey having plasticity and lemon having crosslinking with starch extracted from plants.

According to a feature of the present invention for achieving the above object, an environmentally friendly thermoplastic starch and a method for producing the same according to the present invention are a plastic starch aqueous solution in which starch extracted from plants and a natural material having a diethylene glycol component are mixed. It is characterized in that it is prepared by mixing a natural material having a citric acid component.

The aqueous plastic starch solution is characterized in that honey and water are added to starch extracted from plants, and starch, honey, and water are mixed in a ratio of 10:3:2.

The plastic starch aqueous solution and the natural material having a citric acid component are mixed in a ratio of 4:1.

a step of preparing an aqueous solution of plasticized starch by adding honey and water to starch obtained from a plant and then heating it to a temperature range of 55 to 65° C. to prepare an aqueous solution of plasticized starch; a plastic starch strengthening step of adding a natural material containing citric acid to the plastic starch aqueous solution prepared in the plastic starch aqueous solution preparation step, and then heating it to a temperature range of 75 to 85° C. to improve the physical properties or strength of the plastic starch; It is characterized in that it is prepared including a plastic starch homogenization step of mixing or pulverizing the plastic starch with improved physical properties or strength obtained in the plastic starch strengthening step to have uniform physical properties or particles.

It is characterized in that after performing the step of preparing the aqueous solution of the plasticized starch and after performing the step of strengthening the plasticized starch, a drying step of removing moisture from the prepared plasticized starch is performed.

The drying step includes a primary drying step of partially removing moisture from the aqueous solution of plasticized starch prepared after performing the step of preparing the aqueous solution of plasticized starch, and removing moisture from the aqueous solution of plasticized starch fortified after performing the step of reinforcing the plasticized starch. Then it is characterized in that it consists of a secondary drying step of drying at room temperature.

The plasticized starch homogenization step includes a first homogenization step of manually mixing or pulverizing the plastic starch, and a second homogenization step of mixing or pulverizing the plasticized starch using a ball mill process. .

The eco-friendly thermoplastic starch and its manufacturing method according to the present invention have the following effects.

First, the thermoplastic starch according to an embodiment of the present invention is made by mixing natural starch, honey, and lemon juice. Therefore, unlike the prior art in which starch is manufactured using toxic chemical components, it is more environmentally friendly and has the advantage of preventing environmental pollution.

Second, the honey applied to the present invention contains a component called diethylene glycol. Diethylene glycol is eco-friendly because it does not have a structure of a substance that induces environmental hormones, and it is a component with excellent internal activity due to its plasticity. Therefore, by mixing honey, which is a natural material containing diethylene glycol, with starch, the starch has an effect of increasing plasticity and durability.

Third, the lemon juice applied to the present invention contains a component called citric acid. When citric acid is combined with plastic starch, it causes an esterification reaction with water to form a stronger bond with starch. It prevents separation or separation from it and at the same time causes a crosslinking reaction. Therefore, there is an effect that the strength of the thermoplastic starch can be sufficiently secured by providing excellent physical properties and strength while being environmentally friendly.

Fourth, the thermoplastic starch according to an embodiment of the present invention uses natural materials that can be easily obtained in the vicinity, such as honey and lemon juice. Accordingly, there is an advantage in that the thermoplastic starch can be manufactured at a relatively low price and is excellent in terms of economy.

1 is a flowchart illustrating a method for producing an eco-friendly thermoplastic starch according to an embodiment of the present invention.

Figure 2 is a state diagram showing the molecular structure of the manufacturing process of the aqueous plastic starch aqueous solution according to an embodiment of the present invention.

3 is a state diagram showing the molecular structure of a manufacturing process in which a natural material containing citric acid is added to an aqueous plastic starch solution according to an embodiment of the present invention.

Hereinafter, an environmentally friendly thermoplastic starch and a method for manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a method for manufacturing an eco-friendly thermoplastic starch according to an embodiment of the present invention, and FIG. 2 is a state diagram showing a molecular structure of a manufacturing process of plasticized starch according to an embodiment of the present invention. , FIG. 3 is a state diagram showing a molecular structure of a manufacturing process for imparting crosslinking to plastic starch according to an embodiment of the present invention.

As shown in these drawings, the eco-friendly thermoplastic starch (TPS) of the present invention is made by mixing plastic starch containing honey with a starch extracted from plants and a crosslinking agent containing lemon juice, and then manually and ball milling. It is characterized in that it is manufactured through a (ball mill) process.

As shown in the accompanying FIG. 1 , the environmentally friendly method for producing thermoplastic starch of the present invention includes a plastic starch aqueous solution production step (S100), a primary drying step (S200), a plastic starch strengthening step (S300), and a secondary It is suggested that the drying step (S400) and the plastic starch homogenization step (S500) are included.

The process of manufacturing the thermoplastic starch through each of these steps will be described in more detail for each step as follows.

First, a starch having plasticity is prepared through the above-mentioned plasticized starch aqueous solution preparation step (S100).

In the plastic starch aqueous solution preparation step ( S100 ), honey and water (water, preferably distilled water) are added to the starch extracted from the plant to prepare starch having plasticity.

Here, the starch extracted from plants refers to complex carbohydrates extracted from plants such as corn, grains, potatoes, and the like, and the starch applied to the present invention is corn starch.

The corn starch has advantages of being 100% recyclable and completely biodegradable, easily changeable physically and chemically, inexpensively and readily available.

In addition, the corn starch has an advantage in that it is possible to form a composite material through hydrogen bonding with a hydroxyl group such as water because it has good stability and strong adhesion and can be formed into fine particles.

In the plastic starch prepared through the plastic starch aqueous solution preparation step (S100), honey and water (preferably distilled water) are added to the corn starch in a ratio of 10:3:2.

At this time, the honey contains a component called diethylene glycol that gives plasticity.

Here, diethylene glycol is eco-friendly because it does not have a structure of a substance that induces environmental hormones, and is a component excellent in internal activity by having plasticity.

When the honey containing diethylene glycol is mixed with corn starch, the plasticity and durability of the corn starch can be further improved.

Meanwhile, after adding the corn starch, honey, and water (preferably distilled water) as described above, using a stirrer at a temperature of about 55 to 65° C. at a speed of 300 rpm for about 13 to 17 minutes (preferably 15 minutes) Stir.

By stirring in this way, an aqueous starch solution having plasticity can be obtained.

Then, through the first drying step (S200), moisture is filtered and dried from the aqueous solution of plasticized starch obtained in the step (S100) of preparing the aqueous solution of plasticized starch (S100).

In the first drying step (S200), some moisture contained in the aqueous plastic starch solution is removed using a filter or filter paper.

Then, through the plastic starch strengthening step (S300), the physical properties and strength of the aqueous plastic starch solution from which the primary moisture has been removed in the primary drying step (S200) is strengthened.

In this plasticized starch strengthening step (S300), the plasticized starch aqueous solution and lemon juice are mixed in a ratio of 4:1.

Lemon juice applied to the present invention contains a component called citric acid, where citric acid causes an esterification reaction with water when combined with plastic starch to form a stronger bond with starch.

In addition, when citric acid is heated to a high temperature, a secondary esterification reaction occurs with the starch molecules adjacent thereto, thereby preventing the plasticizer from being separated or separated from the starch and at the same time causing a crosslinking reaction.

After adding the lemon juice containing these components to the aqueous plastic starch solution, the mixture is stirred for about 18 to 22 minutes (preferably 20 minutes) at a speed of 300 rpm in a temperature range of 75 to 85°C.

By stirring in this way, it is possible to obtain an aqueous solution of plasticized starch with improved physical properties and strength.

Then, through the secondary drying step (S400), the water is filtered and dried from the aqueous plastic starch solution having improved physical properties and strength in the plastic starch strengthening step (S300).

In the secondary drying step (S400), moisture contained in the aqueous plastic starch solution is removed using a filter or filter paper, and then dried sufficiently at room temperature.

Through the above steps, it is possible to obtain eco-friendly thermoplastic starch with improved physical properties and strength.

The obtained thermoplastic starch can be applied to the manufacture of plastics and composite materials.

Here, if the size of the particles of the plastic starch from which moisture has been removed in the secondary drying step (S400) is non-uniform, it is also possible to perform the plasticized starch homogenization step (S500) to make them uniform.

The plasticized starch homogenization step (S500) is a step of mixing and pulverizing the plasticized starch prepared through the above steps to achieve uniform physical properties and sizes.

In this plasticized starch homogenization step (S500), the first homogenization step of manually mixing or pulverizing the powdered plastic starch from which moisture has been removed in the secondary drying step (S400), and the mixing or pulverization in the first homogenization step A secondary homogenization step of mixing and pulverizing the plasticized starch again using a ball mill process is included.

The first homogenizing step is a step of manually mixing the plastic starch from which moisture has been removed in the second drying step (S400) in a bag and rubbing the starch by hand.

After performing the first leveling step, the second leveling step is performed. In the second leveling step, the plastic starch and balls mixed in the first leveling step are put together in a container and then a ball mill is used. It is a step of mixing and pulverizing using a process.

Here, in the ball mill process, since the balls continuously strike the starch, heat is generated between molecules constituting the plastic starch, and in this process, an additional crosslinking reaction occurs.

In addition, it is mixed and pulverized to have uniform physical properties and particles, and a finer powder can be prepared.

By performing the above steps, it is possible to obtain a powdered thermoplastic starch having uniform physical properties and particle size.

Accordingly, the thermoplastic starch of the present invention is environmentally friendly and provides excellent physical properties and strength unlike the prior art using toxic chemicals by manufacturing thermoplastic starch using natural materials such as honey and lemon juice to prevent environmental pollution In addition, it is possible to sufficiently secure the strength of thermoplastic starch.

As such, the eco-friendly thermoplastic starch produced by the manufacturing method of the present invention can be obtained relatively easily by manufacturing the thermoplastic starch using natural materials honey and lemon juice, unlike the conventional thermoplastic starch using toxic chemical components. Because it is a material, it is possible to obtain maximum thermoplasticity at minimum cost.

In particular, by using lemon juice containing citric acid that imparts cross-linking properties, the eco-friendly thermoplastic starch produced through the manufacturing method of the present invention has improved properties and strength to obtain thermoplastic starch of excellent quality. be able to

On the other hand, honey and lemon juice applied to the present invention are not limited to the present invention, and any natural material that contains diethylene glycol contained in honey can be applied. Likewise, citric acid contained in lemon juice Any material can be applied as long as it contains natural materials.

For example, as a natural material containing citric acid, in addition to lemon juice, lime, orange, grapefruit, tangerine, pineapple, strawberry, raspberry, cranberry, tomato or cherry, etc. contain citric acid, so these ingredients can be used instead of lemon juice. It could also be applied.

The scope of the present invention is not limited to the embodiments illustrated above, and many other modifications based on the present invention will be possible for those skilled in the art within the above technical scope.

Claims (7)

Eco-friendly thermoplastic starch, characterized in that it is prepared by mixing a natural material having a citric acid component in an aqueous plastic starch solution in which starch extracted from plants and a natural material having a diethylene glycol component are mixed. According to claim 1, wherein the aqueous plastic starch solution, Eco-friendly thermoplastic starch, characterized in that honey and water are added to starch extracted from plants, and starch, honey, and water are mixed in a ratio of 10:3:2. 3. The method of claim 2, Eco-friendly thermoplastic starch, characterized in that the plastic starch aqueous solution and the natural material having a citric acid component are mixed in a ratio of 4:1. a step of preparing an aqueous solution of plasticized starch by adding honey and water to starch obtained from a plant and then heating it to a temperature range of 55 to 65° C. to prepare an aqueous solution of plasticized starch; a plastic starch strengthening step of adding a natural material containing citric acid to the plastic starch aqueous solution prepared in the plastic starch aqueous solution preparation step, and then heating it to a temperature range of 75 to 85° C. to improve the physical properties or strength of the plastic starch; A method for producing an eco-friendly thermoplastic starch, characterized in that it comprises a plastic starch homogenization step of mixing or pulverizing the plastic starch with improved physical properties or strength obtained in the plastic starch strengthening step to have uniform physical properties or particles. [Claim 5] The environmentally friendly thermoplastic starch according to claim 4, wherein a drying step of removing moisture from the prepared plastic starch is performed after performing the plastic starch aqueous solution preparation step and after performing the plastic starch strengthening step. manufacturing method. According to claim 5, wherein the drying step, A first drying step of partially removing moisture from the prepared aqueous solution of plasticized starch after performing the step of preparing the aqueous solution of plasticized starch; A method for producing an eco-friendly thermoplastic starch, characterized in that after performing the step of reinforcing the plasticized starch, a secondary drying step of removing moisture from the reinforced aqueous solution of plasticized starch and drying at room temperature is performed. According to claim 4, wherein the plastic starch homogenization step, A method for producing eco-friendly thermoplastic starch, characterized in that it comprises a first homogenization step of manually mixing or pulverizing the plastic starch, and a second homogenization step of mixing or pulverizing the plastic starch using a ball mill process .

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