KR20220118749A - Method for preparing polypropylene fine particles and polypropylene fine particles prepared by the same - Google Patents

Abstract

The present invention relates to a preparation method of polypropylene microparticles which comprises the step of: preparing a mixed solution by mixing and stirring polypropylene and an organic solvent; phase separation by adding alcohol to the mixed solution; and an obtaining a precipitate from the phase-separated mixed solution and polypropylene microparticles prepared thereby.

Description

Method for producing polypropylene microparticles and polypropylene microparticles prepared thereby

The present invention relates to a method for producing polypropylene microparticles and to polypropylene microparticles produced thereby.

Due to the current coronavirus infection (COVID-19), the use of plastic containers such as disposable cups and bowls has increased significantly, and the use of disposable masks made of polypropylene has increased dramatically.

Plastic products are widely used in household products, medical products, and industrial products such as automobiles. In particular, plastic products made of polypropylene are inexpensive, light, and easy to mold, so they are widely used in food containers, films such as labels, automobile parts, as well as medical devices.

Currently, polystyrene is the most used in the evaluation of the biological and environmental impacts of microplastics because it is the easiest to adjust the size. In addition, in the case of polystyrene, the monomer of styrene is easy to handle, and the polymerization method of polystyrene is also widely spread, so there is an advantage of easy access.

However, most microplastics other than polystyrene are cases in which particles are manufactured through a mechanical pulverization method, and in this case, there are restrictions on the size and shape of the manufactured microplastic particles. In particular, the problem of particle size limitation in the evaluation of bio-effects requiring small-diameter particles, such as evaluation of effects on microstructures, may be more serious.

Among plastic wastes, polypropylene, which is currently used closely in daily life, has very limited supply of nano- and micro-sized particles. Specifically, in the case of polypropylene, since the monomer of propylene is in gaseous form at normal pressure and the polymerization process through the high-pressure reaction must proceed, it is difficult to handle and the polymerization reaction is also difficult.

Therefore, there is a need for research on the preparation of polypropylene microparticles with a simple manufacturing method and easy handling.

US Patent 3971749A (1976.07.27)

An object of the present invention is to solve the above problems, and the present invention is made of a single component of polypropylene, and is easy and simple to manufacture. Nano-sized spherical polypropylene fine particles or micro-sized non-spherical polypropylene fine particles To provide a method for producing particles.

Another object of the present invention is to provide polypropylene microparticles that can be used to evaluate the bio and environmental impact of plastics using the polypropylene microparticles prepared by the method for producing polypropylene microparticles.

The problem to be solved by the present invention is not limited to the problem(s) mentioned above, and another problem(s) not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention comprises the steps of preparing a mixed solution by mixing and stirring polypropylene and an organic solvent; phase separation by adding alcohol to the mixed solution; and obtaining a precipitate from the phase-separated mixed solution; provides a method for producing polypropylene microparticles comprising.

The mixed solution may be prepared at 70 to 140 °C.

The phase separation may be phase separation by stirring the prepared mixed solution at room temperature and rapidly adding alcohol at a rate of 30 to 60 ml/s.

The phase separation may be phase separation by stirring the prepared mixed solution at a temperature of 70 to 140° C., and slowly dropping alcohol at a rate of 0.5 to 5 ml/s.

The mixed solution may have a mixing weight ratio of polypropylene and an organic solvent of 1:35 to 175.

The mixed solution may have a mixing weight ratio of polypropylene and an organic solvent of 1: 10 to 45.

It may be to obtain spherical polypropylene fine particles from the obtained precipitate.

It may be to obtain non-spherical polypropylene microparticles from the obtained precipitate.

The spherical polypropylene microparticles may be 100 to 1000 nm.

The non-spherical polypropylene microparticles may be 0.5 to 10 μm.

The alcohol may be added in an amount of 5 to 15 parts by weight based on 1 part by weight of the organic solvent.

The organic solvent may be at least one selected from the group consisting of xylene, decalin, and monochlorobenzene.

It may further include; filtering the obtained precipitate with a filter and then drying.

The alcohol may include at least one selected from the group consisting of alcohols having 1 to 4 carbon atoms.

The polypropylene may have a weight average molecular weight of 10,000 to 350,000.

In addition, the present invention provides polypropylene particles prepared by the method for producing the polypropylene microparticles.

The polypropylene microparticles may be spherical polypropylene microparticles having a size of 100 to 1000 nm or non-spherical polypropylene microparticles having a size of 0.5 to 10 μm.

In addition, the present invention provides a sample for environmental evaluation of microplastics containing the polypropylene microparticles.

The manufacturing method of the present invention is simple, and it is possible to prepare nano-sized spherical polypropylene microparticles or micro-sized non-spherical polypropylene microparticles using a single polypropylene component that is readily available in the vicinity. . Accordingly, it can be applied as a study to evaluate the bio and environmental impact of plastics or plastic waste, making it easy to supply and supply materials to major research areas and to offset the research gap.

The effects of the present invention are not limited to the above effects, and it should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is an electron micrograph of polypropylene microparticles prepared according to Examples 1 and 2 of the present invention, FIG. 1(a) is an electron micrograph of spherical polypropylene microparticles, and FIG. 1(b) is It is an electron micrograph of non-spherical polypropylene microparticles.
2 is a graph showing the particle size distribution of spherical polypropylene microparticles prepared according to Example 1 of the present invention.
3 is a graph showing the particle size distribution of non-spherical polypropylene microparticles prepared according to Example 2 of the present invention.
4 is an FT-IR graph for analyzing the chemical structure of spherical polypropylene microparticles prepared according to Example 1 of the present invention.
5 is an FT-IR graph for analyzing the chemical structure of non-spherical polypropylene microparticles prepared according to Example 2 of the present invention.

It should be noted that, in the following description, only parts necessary for understanding the embodiments of the present invention are described, and descriptions of other parts may be omitted in a range that does not disturb the gist of the present invention.

At this time, if there is no other definition in the technical terms, scientific terms and abbreviations used, they have the meanings commonly understood by those of ordinary skill in the technical field to which this invention belongs. In addition, repeated description of the same technical configuration and operation as in the prior art will be omitted.

As used herein, the term "spherical microparticles" or "spherical" means round or oval, and "non-spherical microparticles" or "non-spherical" refers to any three-dimensional shape in which the cross section of the particle is not circular or elliptical. it means. For example, “non-spherical microparticles” or “non-spherical” may include qualitatively cubic, rectangular, hexagonal, rod-shaped or needle-shaped.

As used herein, the term "pellet" is a small piece formed by extrusion of a raw material, and includes all shapes classified as pellets in the art, such as round, flat, scale, polygonal, and rod shape. The size is not particularly limited as being appropriately determined depending on the use and shape, but the pellet in the present invention is defined as having an average diameter of 2 to 6 mm so that it can be distinguished from a powder having a small average diameter of 1 mm level. At this time, the "diameter" is the longest distance among arbitrary linear distances of the outer peripheral surface of the pellet, and can be measured using an imaging microscope or the like.

Hereinafter, the present invention will be described in detail.

The present invention comprises the steps of preparing a mixed solution by mixing and stirring polypropylene and an organic solvent; phase separation by adding alcohol to the mixed solution; and obtaining a precipitate from the phase-separated mixed solution; provides a method for producing polypropylene microparticles comprising.

First, a mixed solution is prepared by mixing and stirring polypropylene and an organic solvent.

The mixed solution may be prepared by dissolving the polypropylene in the organic solvent.

The mixed solution may be prepared at 70 to 140 ℃, preferably 90 to 120 ℃. When the mixed solution is prepared within the above temperature range, it is possible to maintain the dissolution stability of the polypropylene in the solvent.

Polypropylene has a degree of solvent solubility limited by its stereoregularity. In order to proceed with the manufacturing method of the present invention, the state of the mixed solution must be maintained in a stable state. To this end, the solubility of the polypropylene in the solvent is increased by heating the organic solvent, and the dissolution stability of the polypropylene is maintained by maintaining a constant temperature of the mixed solution.

At this time, the mixed solution is prepared by mixing the polypropylene and the organic solvent at 70 to 140° C. for 0.1 to 5 hours, preferably 0.1 to 1 hour, preferably at 90° C. until the polypropylene is completely dissolved in the organic solvent. A mixed solution can be prepared by mixing and stirring while heating to 120°C.

As the polypropylene, a commercially available polypropylene used in the production of a polypropylene family that can be easily obtained in daily life may be used, and preferably, a polypropylene having a weight average molecular weight of 10,000 to 350,000 may be used. At this time, the melting point of the polypropylene may be 157 to 165 ℃.

When polypropylene having the above weight average molecular weight and melting point is used, solubility in an organic solvent may be excellent.

The organic solvent may be at least one selected from the group consisting of xylene, toluene, decalin, and monochlorobenzene, preferably xylene.

The xylene may be made of a combination of any one or more selected from the group consisting of ortho-xylene, meta-xylene, and para-xylene.

Next, phase separation is performed by adding alcohol to the mixed solution.

Phase separation by adding alcohol to the mixed solution involves stirring the prepared mixed solution at 70 to 140°C, preferably 90 to 120°C at room temperature, and rapidly adding alcohol at a rate of 30 to 60 ml/s. Phase separation into the supernatant and the lower precipitate, or the prepared 70 to 140 ℃, preferably 90 to 120 ℃ mixed solution is stirred at a temperature of 70 to 140 ℃, preferably 90 to 120 ℃, alcohol It may be to phase-separate into a supernatant and a lower precipitate by dropping it slowly at a rate of 0.5 to 5 ml/s.

The supernatant may be a solution containing an organic solvent and alcohol, and the lower precipitate may be polypropylene microparticles.

The alcohol may include at least one selected from the group consisting of alcohols having 1 to 4 carbon atoms, preferably methanol, ethanol, 1-propanol, butanol, and the like, and more preferably ethanol.

Specifically, the method for producing polypropylene microparticles of the present invention can be produced into spherical microparticles or non-spherical microparticles as follows according to the alcohol treatment method.

(1) Preparation of spherical fine particles

The manufacturing method of the spherical microparticles comprises the steps of: preparing a mixed solution by mixing and stirring polypropylene and an organic solvent; stirring the prepared mixed solution at room temperature, and rapidly adding alcohol to phase-separate; and obtaining a precipitate from the phase-separated mixed solution.

First, a mixed solution is prepared by mixing and stirring polypropylene and an organic solvent.

The mixed solution may be prepared by dissolving the polypropylene in the organic solvent.

The mixed solution may be prepared at 70 to 140 ℃, preferably 90 to 120 ℃. When the mixed solution is prepared within the above temperature range, it is possible to maintain the dissolution stability of the polypropylene in the solvent.

At this time, the mixed solution is prepared by mixing the polypropylene and the organic solvent with the polypropylene for 0.1 to 5 hours, preferably from 0.1 to 1 hour at 70 to 140° C., preferably from 90 to 120 until the polypropylene is completely dissolved in the organic solvent. A mixed solution can be prepared by mixing and stirring while heating to °C.

The polypropylene may have a weight average molecular weight of 10,000 to 350,000. At this time, the melting point of the polypropylene may be 157 to 165 ℃.

When polypropylene having the above weight average molecular weight and melting point is used, solubility in an organic solvent may be excellent.

The organic solvent may be at least one selected from the group consisting of xylene, toluene, decalin, and monochlorobenzene, and preferably xylene.

The xylene may be made of a combination of any one or more selected from the group consisting of ortho-xylene, meta-xylene, and para-xylene.

Next, the prepared mixed solution is stirred at room temperature, and alcohol is rapidly added to phase-separate.

Phase separation by rapidly adding the alcohol may include moving the prepared mixed solution at 70 to 140° C. to room temperature and stirring, and rapidly adding alcohol to phase-separate the supernatant and the lower precipitate.

Specifically, a mixed solution is prepared by mixing and stirring polypropylene and an organic solvent at 70 to 140°C, preferably 90 to 120°C, and then, the mixed solution at 70 to 140°C is heated at room temperature, preferably 15 to 30 While stirring at ℃, alcohol may be added rapidly while maintaining a rate of 30 to 60 ml/s to phase-separate the supernatant and the lower precipitate.

The rapid addition of the alcohol may be to maintain an input rate of 30 to 60 ml/s, and to be continuously added without breaking or dividing.

When the alcohol is rapidly added to the mixed solution at room temperature to perform phase separation, spherical polypropylene fine particles can be obtained from the precipitate obtained from the phase-separated mixed solution, which is a subsequent step.

Specifically, spherical polypropylene fine particles can be obtained from the precipitate obtained from the phase-separated mixed solution by stirring for 5 to 24 hours until the temperature of the mixed solution is lowered to 15 to 30°C.

When preparing the mixed solution, the spherical polypropylene microparticles may have a mixing weight ratio of polypropylene and an organic solvent of 1: 35 to 175. When the organic solvent is added within the above range, it is possible to prepare independent spherical polypropylene microparticles in which agglomeration between particles does not occur.

The alcohol may be added in an amount of 5 to 15 parts by weight based on 1 part by weight of the organic solvent. When alcohol is added within the above range, it is possible to prepare spherical fine particles of polypropylene in an independent form that does not cause a decrease in solubility in the polypropylene mixed solution and thus induce phase separation and agglomeration between particles during phase separation.

Next, a precipitate is obtained from the phase-separated mixed solution.

Spherical polypropylene fine particles can be obtained from the obtained precipitate.

The spherical polypropylene microparticles may have a size of 100 to 1000 nm. As described above, the spherical polypropylene fine particles according to the manufacturing method of the present invention are manufactured into fine particles that are difficult to obtain when polypropylene having a large particle size is pulverized through a physical grinding process, and can be used for evaluation of the biological and environmental impact of plastics. have.

On the other hand, the method for producing the spherical microparticles may further include; filtering the obtained precipitate with a filter and then drying.

As the filter, any material that is not deformed by an organic solvent used for preparing the mixed solution and alcohol used for phase separation may be used, preferably a membrane filter of 0.1 to 0.45 μm, more preferably 0.1 to 0.45 μm of polytetrafluoroethylene (PTFE) membrane filters can be used. By using the filter, since there is no interaction between the surface of the filter and the particles, which are precipitates filtered by the filter, separation of the prepared fine particles from the surface of the filter after drying may be easy.

(2) Preparation of non-spherical microparticles

The manufacturing method of the non-spherical microparticles comprises the steps of: preparing a mixed solution by mixing and stirring polypropylene and an organic solvent; stirring the prepared mixed solution at 70 to 140° C., and slowly dropping alcohol to phase-separate; and obtaining a precipitate from the phase-separated mixed solution.

First, a mixed solution is prepared by mixing and stirring polypropylene and an organic solvent.

The mixed solution may be prepared by dissolving the polypropylene in the organic solvent.

The mixed solution may be prepared at 70 to 140 ℃, preferably 90 to 120 ℃. When the mixed solution is prepared within the above temperature range, it is possible to maintain the dissolution stability of the polypropylene in the solvent.

At this time, the mixed solution is 70 to 140 ℃, preferably 90 to 120 for 0.1 to 5 hours, preferably 0.1 to 1 hour, specifically, polypropylene and the organic solvent until the polypropylene is completely dissolved in the organic solvent. A mixed solution can be prepared by mixing and stirring while heating to °C.

The polypropylene may have a weight average molecular weight of 10,000 to 350,000. At this time, the melting point of the polypropylene may be 157 to 165 ℃.

When polypropylene having the above weight average molecular weight and melting point is used, solubility in an organic solvent may be excellent.

The organic solvent may be at least one selected from the group consisting of xylene, toluene, decalin, and monochlorobenzene, and preferably xylene.

The xylene may be made of a combination of any one or more selected from the group consisting of ortho-xylene, meta-xylene, and para-xylene.

Next, the prepared mixed solution is stirred at 70 to 140° C., and the alcohol is slowly added dropwise to phase-separate.

To perform phase separation by slowly dropping the alcohol, the prepared mixed solution of 70 to 140° C. is stirred while maintaining a temperature of 70 to 140° C., and the alcohol is slowly dropped to separate the phase into a supernatant and a lower precipitate.

Specifically, a mixed solution is prepared by mixing and stirring polypropylene and an organic solvent at 70 to 140°C, preferably 90 to 120°C, and then, 70 to 140°C, preferably 90 to the mixed solution at 70 to 140°C. It may be to phase-separate the supernatant and the lower precipitate by slowly dropping the alcohol at a rate of 0.5 to 5.0 ml/s while continuously stirring at 120°C.

The slow dropping of the alcohol may be to maintain a rate of 0.5 to 5.0 ml/s, and to be continuously added and dropped without breaking or dividing.

When the alcohol is slowly dropped into the mixed solution at 70 to 140° C. to perform phase separation, non-spherical polypropylene fine particles can be obtained from the precipitate obtained from the phase-separated mixed solution, which is a later step.

Specifically, after adding alcohol to the mixed solution dropwise, the mixed solution at 70 to 140° C. is stirred at room temperature, preferably at 15 to 30° C., for 5 to 24 hours, and then a non-spherical form from the precipitate obtained from the phase-separated mixed solution. Polypropylene microparticles can be obtained.

In the non-spherical polypropylene microparticles, when the mixed solution is prepared, the mixing weight ratio of polypropylene and the organic solvent may be 1: 10 to 45. When the organic solvent is added within the above range, it is possible to prepare non-spherical polypropylene microparticles of independent form that do not cause agglomeration between particles.

The alcohol may be added in an amount of 5 to 15 parts by weight based on 1 part by weight of the organic solvent. When alcohol is added within the above range, it is possible to prepare non-spherical fine particles of polypropylene in an independent form that does not cause a decrease in solubility in the polypropylene mixed solution and thus induction of phase separation and agglomeration between particles during phase separation.

Next, a precipitate is obtained from the phase-separated mixed solution.

Non-spherical polypropylene fine particles can be obtained from the obtained precipitate.

The non-spherical polypropylene microparticles may be 0.5 to 10 μm. As described above, the spherical polypropylene fine particles according to the manufacturing method of the present invention are manufactured into fine particles that are difficult to obtain when polypropylene having a large particle size is pulverized through a physical grinding process, and can be used for evaluation of the biological and environmental impact of plastics. have.

On the other hand, the method for producing the non-spherical microparticles may further include the step of filtering the obtained precipitate with a filter and then drying.

The filter may be any material that is not deformed by an organic solvent used for preparing the mixed solution and alcohol used for phase separation, preferably a membrane filter of 0.1 to 0.45 μm, more preferably 0.1 to 0.45 μm of polytetrafluoroethylene (PTFE) membrane filters can be used. By using the filter, since there is no interaction between the surface of the filter and the particles, which are precipitates filtered by the filter, separation of the prepared fine particles from the surface of the filter after drying may be easy.

In addition, the present invention provides a polypropylene microparticle prepared by the method for producing the polypropylene microparticle.

The polypropylene particles may be spherical polypropylene microparticles having a size of 100 to 1000 nm or non-spherical polypropylene microparticles having a size of 0.5 to 10 μm.

In addition, the present invention provides a sample for environmental evaluation of microplastics containing the polypropylene microparticles.

The above description describes the technical idea of the present invention using one embodiment, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Accordingly, the embodiments described in the present invention are not intended to limit the technical spirit of the present invention, but to illustrate, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Example

Example 1: Preparation of spherical polypropylene microparticles

In a 500ml round flask, 0.13g of polypropylene pellets (Sigma-Aldrich, Polypropylene, Product ID:427888, Isotactic, average Mw ~250,000, average Mn ~67,000) and 17.6g of xylene were mixed and stirred at 110℃ to prepare a mixed solution, , and stirred for 0.5 hours until the polypropylene pellets in the mixed solution were completely dissolved. The mixed solution at 110° C. in which the polypropylene pellets were completely dissolved was stirred at a temperature of 25° C., and 160 g of ethanol was rapidly added at a rate of 40 ml/s. Then, the mixed solution was stirred at 25° C. for 15 hours, and the phase-separated precipitate was filtered using a 0.2 μm polytetrafluoroethylene (PTFE) membrane filter. After drying in an oven at 80° C. for 24 hours, spherical polypropylene fine particles in a powder state were obtained, and the average particle diameter and deviation were 360±120 nm.

Example 2: Preparation of non-spherical polypropylene microparticles

In a 500ml round flask, 0.25g of polypropylene pellets (Sigma-Aldrich, Polypropylene, Product ID:427888, Isotactic, average Mw ~250,000, average Mn ~67,000) and 8.8g of xylene were mixed and stirred at 110℃ to prepare a mixed solution, , and stirred for 0.5 hours until the polypropylene pellets in the mixed solution were completely dissolved. The mixed solution in which the polypropylene pellets were completely dissolved was stirred to maintain 110° C., and 39.5 g of ethanol was slowly added at a rate of 1.0 ml/sec using the cock of a separatory funnel. Immediately after the addition of ethanol was completed, the mixed solution was stirred for 15 hours in a fume hood at room temperature at 25° C., and then the phase-separated precipitate was filtered using a 0.2 μm polytetrafluoroethylene (PTFE) membrane filter. After drying in an oven at 80° C. for 24 hours, non-spherical polypropylene fine particles in a powder state were obtained, and the average particle diameter and deviation were 3.92±1.12 μm.

Example 3

In Example 1, 8.8 g was used instead of 17.6 g of xylene, and 80 g was used instead of 160 g of ethanol. It was carried out under the same method and conditions as in Example 1 to obtain spherical polypropylene fine particles, and The deviation is 580±240 nm.

Example 4

In Example 1, 0.25 g was used instead of 0.13 g of polypropylene pellets, 8.8 g was used instead of 17.6 g of xylene, and 80 g was used instead of 160 g of ethanol. of polypropylene microparticles were obtained, and the average particle diameter and deviation were 690±220 nm.

Example 5

Spherical polypropylene microparticles were obtained in the same manner and under the same conditions as in Example 2, except that in Example 2, the ethanol input rate was gradually added at 5.0 ml/sec instead of 1.0 ml/sec, and the average particle size and The deviation is 1.26±0.68μm.

comparative example

Comparative Example 1: When the concentration of the mixed solution is out of range

Example 1 was carried out under the same method and conditions as in Example 1, except that 35.2 g of xylene was used instead of 17.6 g of xylene. In this case, there was no separation between the particles and agglomeration occurred.

Comparative Example 2: When ethanol was not added

In a 500ml round flask, 0.1g of polypropylene pellets (Sigma-Aldrich, Polypropylene, Product ID:427888, Isotactic, average Mw ~250,000, average Mn ~67,000) and 8.8g of xylene were mixed and stirred at 110℃ to prepare a mixed solution, , and stirred for 0.5 hours until the polypropylene pellets in the mixed solution were completely dissolved. The mixed solution at 110° C. in which the polypropylene pellets were completely dissolved was stirred at 25° C. for 15 hours, and the phase-separated precipitate was filtered using a 0.2 μm polytetrafluoroethylene (PTFE) membrane filter. Thereafter, after drying in an oven at 80° C. for 24 hours, non-spherical polypropylene fine particles in a powder state were obtained, and the average particle diameter and deviation were 240±60 nm.

Comparative Example 3: When ethanol is not added

In a 500ml round flask, 0.1g of polypropylene pellets (Sigma-Aldrich, Polypropylene, Product ID:427888, Isotactic, average Mw ~250,000, average Mn ~67,000) and 17.6g of xylene were mixed and stirred at 110℃ to prepare a mixed solution, , and stirred for 0.5 hours until the polypropylene pellets in the mixed solution were completely dissolved. The mixed solution at 110° C. in which the polypropylene pellets were completely dissolved was stirred at 25° C. for 15 hours, and the phase-separated precipitate was filtered using a 0.2 μm polytetrafluoroethylene (PTFE) membrane filter. After drying in an oven at 80° C. for 24 hours, non-spherical polypropylene fine particles in a powder state were obtained, and the average particle diameter and deviation were 21.91±8.52 μm.

Comparative Example 4

In Example 2, 7.9 g was used instead of 39.5 g of ethanol, and the same method and conditions as in Example 2 were performed except that the ethanol input rate was gradually added at 0.6 ml/sec instead of 1.0 ml/sec. In this case, there was no separation between the particles and agglomeration occurred.

Experimental example

Experimental Example 1: Structural Analysis

1) Field emission scanning microscopy measurements

In order to confirm the shape of the spherical polypropylene microparticles and non-spherical polypropylene microparticles prepared in Examples 1 and 2, a field emission scanning electron microscope (Magellan400, FEI company (USA)) was measured. did. The results are shown in Fig. 1, Fig. 1 (a) is a field emission scanning electron micrograph of spherical polypropylene microparticles, and Fig. 1 (b) is a field emission scanning electron micrograph of non-spherical polypropylene microparticles. It's a photo.

2) FT-IR measurement

FT-IR spectroscopy (Fourier-transform infrared spectroscopy, ATR mode measurement, Alpha-P , Bruker (USA)). The results are shown in FIGS. 4 and 5, where FIG. 4 is an FT-IR graph of spherical polypropylene nanoparticles, and FIG. 5 is an FT-IR graph of non-spherical polypropylene microparticles.

As can be seen in Figures 4 and 5, in the case of the present invention, it can be confirmed that even after the preparation of the fine particles through the mixed solution has the same chemical composition as the polypropylene used in the experiment. It was confirmed that, after simple dissolution by a solvent, only the size of the simple composition was changed without chemical or polymer structural change of polypropylene.

Experimental Example 2: Measurement of particle size distribution

The particle size distribution of the spherical polypropylene nanoparticles and non-spherical polypropylene microparticles prepared in Examples 1 and 2 was measured.

The particle size distribution was measured using the ImageJ program based on the SEM image of FIG. 1 . The results are shown in FIGS. 3 and 4 .

Although specific examples of the method for manufacturing polypropylene microparticles according to the present invention have been described so far, it is obvious that various implementation modifications are possible within the limits that do not depart from the scope of the present invention.

Therefore, the scope of the present invention should not be limited to the described embodiments, and should be defined by the following claims as well as the claims and equivalents.

That is, it should be understood that the above-described embodiment is illustrative in all respects and not restrictive, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims; All changes or modifications derived from the equivalent concept should be construed as being included in the scope of the present invention.

Claims (18)

preparing a mixed solution by mixing and stirring polypropylene and an organic solvent;
phase separation by adding alcohol to the mixed solution; and
A method for producing polypropylene microparticles comprising; obtaining a precipitate from the phase-separated mixed solution. According to claim 1,
The mixed solution is prepared at 70 to 140 ℃, the method for producing polypropylene fine particles. According to claim 1,
In the phase separation, the prepared mixed solution is stirred at room temperature, and alcohol is added at a rate of 30 to 60 ml/s to perform phase separation. According to claim 1,
In the phase separation, the prepared mixed solution is stirred at a temperature of 70 to 140° C., and alcohol is added dropwise at a rate of 0.5 to 5 ml/s to perform phase separation. 4. The method of claim 3,
The mixed solution is a method for producing polypropylene microparticles, wherein the mixing weight ratio of polypropylene and organic solvent is 1: 35 to 175. 5. The method of claim 4,
The mixed solution is a method for producing polypropylene microparticles, wherein the mixing weight ratio of polypropylene and the organic solvent is 1: 10 to 45. 4. The method of claim 3,
The precipitate is a spherical polypropylene microparticles, the method for producing polypropylene microparticles. 5. The method of claim 4,
The method for producing polypropylene microparticles, wherein the precipitate is non-spherical polypropylene microparticles. 8. The method of claim 7,
The spherical polypropylene microparticles have a size of 100 to 1000 nm, a method for producing polypropylene microparticles. 9. The method of claim 8,
The non-spherical polypropylene microparticles have a size of 0.5 to 10 μm, a method for producing polypropylene microparticles. According to claim 1,
The alcohol is added in an amount of 5 to 15 parts by weight based on 1 part by weight of the organic solvent, a method for producing polypropylene microparticles. According to claim 1,
The organic solvent is at least one selected from the group consisting of xylene, toluene, decalin, and monochlorobenzene. According to claim 1,
The method for producing polypropylene microparticles, further comprising; filtering the obtained precipitate with a filter and then drying. According to claim 1,
The alcohol is a method for producing polypropylene microparticles comprising at least one selected from the group consisting of alcohols having 1 to 4 carbon atoms. According to claim 1,
The weight average molecular weight of the polypropylene will be 10,000 to 350,000, the method for producing polypropylene fine particles. The polypropylene microparticles prepared by the manufacturing method according to claim 1 . 17. The method of claim 16,
The polypropylene microparticles are spherical polypropylene microparticles having a size of 100 to 1000 nm or non-spherical polypropylene microparticles having a size of 0.5 to 10 μm, polypropylene microparticles. A sample for environmental evaluation of microplastics comprising the polypropylene microparticles according to claim 17.

Images