KR102249837B1 - Bio-Degradable Micro-plastic Including Photocatalyst and Manufacturing Method Thereof - Google Patents

Abstract

Disclosed is a biodegradable microplastic comprising a photocatalyst and a method for producing the same.
According to one aspect of the present embodiment, a core layer composed of a photocatalyst and a biodegradable plastic resin, surround the surface of the core layer, and include a resin layer that is decomposed by the core layer. Provide plastic.

Description

Bio-Degradable Micro-plastic Including Photocatalyst and Manufacturing Method Thereof}

The present invention relates to a biodegradable microplastic comprising a photocatalyst having an improved decomposition rate, and a method for producing the same.

The content described in this section merely provides background information on the present embodiment and does not constitute the prior art.

Microplastic (or microbeads) refers to plastics having a size of 5 mm or less, and is mainly added to household products such as cosmetics, scrubs, toothpastes, and the like. Because microplastics are very small in size and are not filtered in sewage treatment facilities, they are introduced into rivers or seas as they are, so they are emerging as a serious cause of environmental pollution.

In general, microplastics are composed of petroleum chemicals such as polyethylene (PE), polypropylene (PP), and polystyrene (PS), and have a property that does not decompose over time. In addition, since microplastics have a large surface area, other chemicals in water (e.g., polychlorinated biphenyl (PCB), dichloro-diphenyl-dichloro-ethylene (DDE), nonylphenol (NPEs), etc.)) It creates new pollutants by adsorbing it. If marine organisms ingest microplastics because they are mistaken for food, they can have a harmful effect on humans as well, depending on the accumulation of the food chain.

In order to solve this problem, research on raw materials for microplastics has been actively conducted in recent years. In other words, efforts are being made to prevent environmental pollution by microplastics by using materials that are decomposed by light, microorganisms, hydrolysis, temperature, and enzymes as raw materials for microplastics. In particular, biodegradable materials that are decomposed by microorganisms and enzymes are similar in strength, water resistance, molding processability and heat resistance to general chemical substances, and are environmentally friendly as they are decomposed into carbon dioxide, water, and inorganic salts.

However, in order for biodegradable resins to be decomposed in nature, UV-B (Ultraviolet B) with a wavelength of 290 to 315 nm or more or 4,000 kcal or more is required. If these conditions are not met, it takes a long time for the biodegradable resin to decompose. Therefore, there is a need for a material that can be decomposed at a relatively high speed with little energy.

An object of the present invention is to provide a biodegradable microplastic including a photocatalyst, and a method for manufacturing the same, having an improved decomposition rate.

According to an aspect of the present invention, a core layer composed of a photocatalyst; And a resin layer composed of a biodegradable plastic resin, surrounding the surface of the core layer, and decomposed by the core layer.

According to an aspect of the present invention, the core layer is characterized in that it is composed _{of spherical TiO 2 particles.}

According to one aspect of the invention, the core layer is characterized in that the photocatalytic reaction is irradiated with light of a predetermined wavelength band.

According to an aspect of the present invention, the resin layer is characterized in that consisting of PLA (Poly Lactic Acid or Polylactide).

According to an aspect of the present invention, the resin layer is characterized in that it is decomposed by microorganisms or yeast.

According to an aspect of the present invention, the resin layer is characterized in that it is formed by a polymerization reaction on the surface of the core layer.

According to an aspect of the present invention, there is provided a method for manufacturing a biodegradable microplastic comprising a core layer and a resin layer, comprising: preparing a core layer for preparing the core layer; An aqueous solution immersion process in which the core layer _{is immersed in an aqueous NH 4 OH solution;} A first heating process of heating the aqueous solution in a first preset environment; A washing and drying process of removing, washing and drying the core layer; An organic solvent immersion process in which the core layer is immersed in an organic solvent; A precursor addition process of adding a precursor of a polymer for forming the resin layer to the organic solvent; Adding a catalyst to a mixture of the organic solvent, the polymer precursor, and the core layer, adding a catalyst for accelerating the polymerization reaction of the polymer precursor on the surface of the core layer; And a second heating process of heating a mixture of the organic solvent, the polymer precursor, the core layer, and the catalyst in a second predetermined environment.

According to an aspect of the present invention, the core layer is characterized in that it is composed _{of spherical TiO 2 particles.}

According to an aspect of the present invention, the aqueous solution immersion process is characterized in that a hydroxyl group (-OH) is formed on the surface of the core layer.

According to an aspect of the present invention, the hydroxyl group is characterized in that the polymerization reaction with the precursor of the polymer.

According to an aspect of the present invention, the precursor of the polymer is characterized in that it is composed of Lactide.

According to an aspect of the present invention, the catalyst addition process is characterized in that it promotes a reaction in which the precursor of the polymer is polymerized into PLA on the surface of the core layer.

According to an aspect of the present invention, as the precursor of the polymer is polymerized into PLA on the surface of the core layer, the resin layer is formed on the surface of the core layer.

As described above, according to an aspect of the present invention, there is an advantage that the decomposition rate can be improved by promoting decomposition of the biodegradable plastic resin including the core layer composed of _{TiO 2 particles.}

1 is a diagram showing the structure of a biodegradable microplastic including a photocatalyst according to an embodiment of the present invention.
2 is a view showing a photocatalytic reaction in a core layer and a process of decomposing a resin layer according to an embodiment of the present invention.
3 is a flowchart illustrating a process of manufacturing a biodegradable microplastic including a photocatalyst according to an embodiment of the present invention.
4 is a view showing a state in which a resin layer is formed on the surface of the core layer according to an embodiment of the present invention.

In the present invention, various changes may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all changes, equivalents, or substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals have been used for similar elements.

Terms such as first, second, A, and B may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. It should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" should be understood as not precluding the possibility of existence or addition of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. .

Unless otherwise defined, all terms including technical or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

In addition, each configuration, process, process, or method included in each embodiment of the present invention may be technically shared within a range that does not contradict each other.

1 is a diagram showing the structure of a biodegradable microplastic including a photocatalyst according to an embodiment of the present invention.

Referring to FIG. 1, a biodegradable microplastic (100, hereinafter abbreviated as'biodegradable microplastic') containing a photocatalyst is a biodegradable plastic resin layer 120 (hereinafter, hereinafter'resin layer') on the surface of the core layer 110. Abbreviation) is composed of a shell-like enclosed shape. Here, the resin layer 120 is made of a biodegradable plastic resin, and is decomposed into water, carbon dioxide, and inorganic salts by microorganisms or yeast. That is, the biodegradable plastic resin in the polymer state is decomposed into low molecules by hydrolysis or microorganisms existing in nature, and finally, by biodegradation, it is completely decomposed from low molecules into water, carbon dioxide and inorganic salts. Typically, it takes up to 6 months or more for the biodegradable plastic resin to be completely decomposed into water, carbon dioxide, and inorganic salts in the polymer. The biodegradable microplastic 100 according to an embodiment of the present invention includes the core layer 110 composed of a photocatalyst, thereby improving the rate at which the biodegradable plastic resin is decomposed. That is, the by-products generated by the photocatalytic reaction in the core layer 110 accelerate the decomposition of the resin layer 120 composed of biodegradable plastic resin, and the biodegradable microplastic 100 introduced into the river or sea is relatively quick. So that it can be disassembled within.

The biodegradable microplastic 100 includes a core layer 110 and a resin layer 120.

Core layer 110 being composed of a spherical TiO ₂ (or titanium dioxide) particles, as is the group waveband set light irradiation ^· OH (or the OH radical (Radical)) and ^· O ₂ ^- (OR O ₂ ^- radical). ^· OH and ^· O ₂ ^- generated by the photocatalytic reaction in the core layer 110 reacts with the resin layer 120, thereby promoting the decomposition of the biodegradable microplastic 100. As described above, the core layer 110 _{is composed of spherical TiO 2} particles, but is not limited thereto, and is composed of a material that causes a photocatalytic reaction by light of a preset wavelength band such as _{ZnO, ZrO 2} , WO _{3, etc.} It could be. The photocatalytic reaction in the core layer 110 will be described later with reference to FIG. 2.

The resin layer 120 is made of PLA (Poly Lactic Acid or Polylactide), and has a shape surrounding the surface of the core layer 110. As described above, the resin layer 120 has a property of being decomposed into water, carbon dioxide, and inorganic salts by microorganisms or yeast. Further, the resin layer 120 is decomposed from a polymer to a monomer by reacting with a material generated by a photocatalytic reaction in the core layer 110. As described above, the resin layer 120 is composed of PLA, but is not necessarily limited thereto, and biodegradation that is degraded by microorganisms or yeast, such as PCL (Polycaprolactone), AP (Aliphatic Polyester), PHB (Poly Hydroxy Butyrate), etc. It may also be composed of a plastic resin. A process in which the resin layer 120 is decomposed from a polymer to a monomer will be described in detail with reference to FIG. 2.

2 is a view showing a photocatalytic reaction in a core layer and a process of decomposing a resin layer according to an embodiment of the present invention.

As shown in FIG. 2, a photocatalytic reaction occurs in the core layer 110, and by-products generated by the photocatalytic reaction act with the resin layer 120. That is, the resin layer 120 is naturally decomposed by microorganisms or yeast, and at the same time, by the core layer 110, the polymer is decomposed into a monomer. The photocatalytic reaction in the core layer 110 and the reaction in which the resin layer 120 is decomposed from poly to monomer can be represented by the following equation.

_{(1) TiO 2 + hv (} > 3.2eV) → TiO 2 (e CB - + h VB +)

(2) TiO ₂ (h _VB ⁺ ) + H ₂ O _(ads) → TiO ₂ + H ⁺ + ^· OH

_{(3) TiO 2 (e CB} -) + O 2 (ads) → TiO 2 + · O 2 -

^{(4) · OH or · O} 2 - + Organic → Oxidative Products

(5)

As is the group waveband set light irradiation photons core layer 110 within the electronics (Electron, e ^-) and where the to the conduction band (Conduction Band, CB) from the valence band (Valence Band, VB), the valence band (VB ) Leaves a hole (Hole, h ⁺ ). Here, the positive hole (h ⁺⁾ are electron (e ^-) of generating a ^· OH by reaction with H ₂ O, and the conduction band (CB) of the valence band (VB) ^- generates is ^· O ₂ reacts with O _2. And as ^· OH and ^· O ₂ ^- react with the resin layer 120, PLA (ie, polymer) in the resin layer 120 is decomposed into Latic Acid (lactic acid, that is, monomer).

3 is a flow chart showing a process of manufacturing a biodegradable microplastic according to an embodiment of the present invention.

The core layer 110 is prepared (S310). A manufacturing apparatus (not shown) or the like prepares a core layer 110 composed _{of spherical TiO 2 particles.}

The core layer 110 _{is immersed in an aqueous NH 4} OH solution (S320). A manufacturing apparatus (not shown) or the like allows a plurality of -OH (or hydroxyl groups) to be formed on the surface of the core layer 110 by immersing the core layer 110 in an aqueous _{NH 4 OH solution.} The number of -OH formed on the surface of the core layer 110 may be adjusted according to the concentration of the aqueous _{NH 4 OH solution. Here, the concentration of the aqueous NH 4} OH solution in which the core layer 110 is immersed may be 1 to 4M (Mol, mole).

Heated in a first preset environment (S330). A manufacturing apparatus (not shown) or the like _{heats the core layer 110 immersed in the NH 4} OH aqueous solution in a first preset environment, so that the subsequent process can be smoothly performed. A manufacturing apparatus (not shown) or the like is provided with a reflux condenser (not shown), and the like, _{thereby condensing the vapor generated as the NH 4} OH aqueous solution is heated to return it to a liquid. By this process, _{the concentration of the aqueous NH 4} OH solution can be kept constant.

The _{core layer 110 is filtered from the aqueous NH 4} OH solution, washed and dried (S340). A manufacturing apparatus (not shown) or the like _{filters the core layer 110 from the heated NH 4} OH aqueous solution (ie, filtering), and then is dried after washing.

The core layer 110 is immersed in an organic solvent (S350). A manufacturing apparatus (not shown) or the like immerses the washed and dried core layer 110 in an organic solvent. As the core layer 110 is immersed in the organic solvent, the resin layer 120 may be smoothly attached to the surface of the core layer 110. The organic solvent may be composed of toluene, but is not limited thereto.

Lactide is added to the organic solvent (S360). A manufacturing apparatus (not shown) or the like adds Lactide (lactide) in the organic solvent in which the core layer 110 is immersed. Lactide is a precursor (precursor) of PLA (ie, polymer), and as Lactide is added, PLA is formed on the surface of the core layer 110 by a polymerization reaction to be described later.

A catalyst is added to the mixture of the core layer 110, the organic solvent, and the lactide (S370). As a manufacturing apparatus (not shown) or the like adds a catalyst to a mixture in which the core layer 110, an organic solvent, and lactide are mixed, Lactide is polymerized into PLA by reacting with -OH on the surface of the core layer 110. That is, as PLA is polymerized on the surface of the core layer 110, the resin layer 120 having a preset thickness is formed. Here, the thickness of the resin layer 120 may be controlled by the concentration of lactide and catalyst. The catalyst may be composed of 4-Dimethylaminopyridine, but is not limited thereto.

Heating is performed in a preset second environment (S380). As the manufacturing apparatus (not shown) or the like heats the mixture in a preset second environment, the polymerization reaction occurring on the surface of the core layer 110 is smoothly performed. By this manufacturing process, the biodegradable microplastic 100 including the core layer 110 and the resin layer 120 is manufactured.

The manufactured biodegradable microplastic 100 is washed and dried (S390).

4 is a view showing a state in which a resin layer is formed on the surface of the core layer according to an embodiment of the present invention.

Referring to FIG. 4A, as described above, as the core layer 110 _{is immersed in the NH 4} OH aqueous solution, a plurality of -OH is formed on the surface of the core layer 110. A plurality of -OH formed on the surface of the core layer 110 polymerizes with Lactide.

As shown in Figure 4 (b), as a plurality of -OH and Lactide formed on the surface of the core layer 110 by the catalyst polymerization reaction, PLA is formed. That is, the resin layer 120 is composed of PLA, and is composed of a shape surrounding the surface of the core layer 110.

In FIG. 3, it is described that each process is sequentially executed, but this is merely illustrative of the technical idea of an embodiment of the present invention. In other words, a person of ordinary skill in the art to which an embodiment of the present invention pertains may change the order shown in FIG. 3 and execute one or more of each process without departing from the essential characteristics of an embodiment of the present invention. Since it is executed in parallel and can be applied by various modifications and variations, FIG. 3 is not limited to a time series order.

Meanwhile, the processes shown in FIG. 3 can be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. That is, the computer-readable recording medium includes storage media such as magnetic storage media (eg, ROM, floppy disk, hard disk, etc.) and optical reading media (eg, CD-ROM, DVD, etc.). In addition, the computer-readable recording medium can be distributed over a computer system connected through a network to store and execute computer-readable codes in a distributed manner.

The above description is merely illustrative of the technical idea of the present embodiment, and those of ordinary skill in the technical field to which the present embodiment pertains will be able to make various modifications and variations without departing from the essential characteristics of the present embodiment. Accordingly, the present embodiments are not intended to limit the technical idea of the present embodiment, but to explain the technical idea, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of this embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present embodiment.

100: biodegradable microplastic
110: core layer
120: resin layer

Claims (13)

delete delete delete delete delete delete In the biodegradable microplastic manufacturing method comprising a core layer and a resin layer,
Preparing a core layer for preparing a core layer composed of spherical TiO _{2 particles;}
An aqueous solution immersion process in which the core layer is immersed in an aqueous NH ₄ OH solution to form a plurality of hydroxyl groups on the surface of the core layer;
A first heating process of heating the aqueous solution in a predetermined first environment and condensing and liquefying vapor generated as the _{NH 4 OH aqueous solution is heated;}
A washing and drying process of removing, washing and drying the core layer;
An organic solvent immersion process of immersing the core layer in an organic solvent so that the resin layer can be smoothly attached to the surface of the core layer;
A precursor addition process of adding a precursor of a polymer for forming the resin layer to the organic solvent;
Adding a catalyst to a mixture of the organic solvent, the polymer precursor, and the core layer to promote polymerization of the polymer precursor on the surface of the core layer; And
A second heating process of heating a mixture of the organic solvent, the polymer precursor, the core layer, and the catalyst in a preset second environment
Biodegradable microplastic manufacturing method comprising a.
delete delete delete delete delete delete

Images