KR102121936B1 - Method for manufacturing of polystyrene fiber using electrospinning - Google Patents

Abstract

The present invention relates to a polystyrene fiber manufacturing method using electrospinning, which is harmless to a human body and has excellent fiber productivity and, more specifically, to a polystyrene fiber manufacturing method comprising the steps of: dissolving polystyrene using a mixed solvent for electrospinning in which cyclohexanone and ethyl acetate are mixed; and generating polystyrene fibers by applying high voltage current in a process of spraying a polystyrene solution in which the polystyrene is dissolved in the mixed solvent for electrospinning through a spray nozzle.

Description

Method for manufacturing of polystyrene fiber using electrospinning}

The present invention relates to a technique for producing polystyrene fibers, and more particularly, to a method for producing polystyrene fibers using electrospinning.

Typical chemical nanofiber yarns have a wide range of commercial applications in a number of textile applications, such as knitted fabrics and woven fabrics, as well as nonwoven fabrics, such as spunbonded fabrics. Chemical nanofibers are manufactured by a so-called melt spinning process, and melt spinning uses an electrospinning method in which a polymer is melted and sprayed through a spray nozzle to apply electricity in the spray process.

The electrospinning method is a technique for manufacturing a chemical nanofiber yarn having a wide diameter range of several nanometers to several micrometers by applying a high electric field to a polymer solution or a molten material. Electrospinning uses the repulsive force of a charge or dipole. Specifically, the polymer solution of a specific concentration is moved to the end of the capillary tube, and the polymer droplet formed by the surface tension is given an electrostatic force, so that the electrostatic force transmitted to the surface of the droplet generates a force opposite to the surface tension due to charge or dipole repulsion. As the opposing force becomes larger than the surface tension, a jet of a polymer solution is sprayed to form fibers. At this time, due to the elongation and whipping phenomenon of the jet being jetted, it is moved to the dust collecting plate to be collected to produce a fiber membrane. This characteristic of electrospinning can be applied to a wide range of materials and nano and microfibers can be produced with simple devices and equipment compared to other spinning methods. The shape of the fiber produced by electrospinning depends on the concentration and viscoelasticity of the polymer solution or molten material, as well as the voltage applied to the solution, which is a variable in the electrospinning process, and the flow rate of the solution. In addition, what is considered as a particularly important variable for fiber formation from the electrospinning of the polymer may exemplify properties such as the boiling point, conductivity and surface tension of the solvent dissolving the polymer.

On the other hand, when a hydrophobic polymer such as polystyrene is used for electrospinning, organic solvents such as Dimethylformamide (DMF) and Tetrahydrofuran (THF) are mainly used as a solvent, and among them, DMF is mainly used. However, DMF and THF each have a potential risk to humans, including genetic toxicity, teratogenicity and carcinogenicity to certain animals. DMF and THF have a NFPA 704 Health hazard class of 2, which is a substance that can harm a person if a large amount is inhaled at a time or a small amount is continuously inhaled. Accordingly, it is reported that DMF in the air easily causes respiratory toxicity and skin toxicity, and acts as a factor that infiltrates the skin and causes various diseases, and it has recently been revealed that it is a hepatotoxic substance that can cause liver dysfunction. . In addition, as a result of the oral toxicity animal test of THF, the LD50 value was confirmed to be 1900-2900 mg/kg, and in the case of inhaler toxicity, over 20000 mg/L, it could show fatal toxicity within 1 h. In addition, it has been found that THF is a substance capable of causing skin and mucous membrane (eye, nose, etc.) damage even at a concentration of 100-200 mg/L.

Therefore, there is a need for a method for producing polystyrene fiber by a solvent that excludes the use of DMF and THF as a solvent for producing polystyrene fiber using electrospinning, is harmless to humans and has a superior or at least the same performance as DMF or THF solvent. have.

The problem to be solved by the present invention relates to a method for producing polystyrene fibers using electrospinning, which is harmless to the human body and has excellent fiber productivity in the production of polystyrene fibers.

The method for producing polystyrene fibers using electrospinning according to the present invention for solving the above problems is to dissolve polystyrene (Polystyrene) using a mixed solvent of cyclohexanone (Cyclohexanone) and ethyl acetate (Ethyl acetate). Letting; And generating a polystyrene fiber by applying a high voltage current in the process of spraying the polystyrene solution in which the polystyrene is dissolved in the mixed solvent for electrospinning through a spray nozzle.

The composition ratio of the electrospinning mixed solvent and the polystyrene is characterized in that the electrospinning mixed solvent: the polystyrene = 70 [%] to 80 [%]: 20 [%] to 30 [%].

The composition ratio of the electrospinning mixed solvent and the polystyrene is characterized in that the electrospinning mixed solvent: the polystyrene = 75 [%]: 25 [%].

The composition ratio of the cyclohexanone and the ethyl acetate is characterized in that the cyclohexanone: the ethyl acetate = 40 [%] to 60 [%]: 40 [%] to 60 [%].

The composition ratio of the cyclohexanone and the ethyl acetate is characterized in that the cyclohexanone: the ethyl acetate = 50 [%]: 50 [%].

The step of dissolving the polystyrene in the electrospinning mixed solvent is to form a composition ratio of the polystyrene and the electrospinning mixed solvent such that the viscosity of the polystyrene solution is 1500 [mPA-s] to 2500 [mPA-s]. It is characterized by.

In the step of generating the polystyrene fiber, the temperature of the space in which the polystyrene solution is injected through the injection nozzle is characterized in that it is 25 [°C] to 30 [°C].

In the step of generating the polystyrene fiber, the humidity of the space in which the polystyrene solution is injected through the spray nozzle is 45[%] to 55[%].

The step of generating the polystyrene fiber is characterized in that the diameter of the injection nozzle to which the polystyrene solution is injected is 0.25 [mm].

According to the present invention, by preparing polystyrene fibers using cyclohexanone and ethyl acetate as an electrospinning mixed solvent having very low oral toxicity, chronicity, or neurotoxicity, etc. In the fiber manufacturing process, it is possible to form a manufacturing environment that is harmless to the human body, and it is possible to extend the manufacturing time of the polystyrene fiber, thereby improving work efficiency.

In addition, by using cyclohexanone and ethyl acetate as a mixed solvent for electrospinning to produce polystyrene fibers, there is an effect of increasing the productivity of polystyrene by 2 to 3 times or more compared to the prior art.

1 is a reference diagram illustrating device components for manufacturing an electrospun polystyrene fiber.
Figure 2 is a flow chart of an embodiment for explaining a method for producing polystyrene fiber using electrospinning according to the present invention.
3 is a graph illustrating the change in solution viscosity according to the composition ratio between the mixed solvent for electrospinning and polystyrene.
4 is a reference diagram illustrating a polystyrene fiber produced using a mixed solvent of cyclohexanone and ethyl acetate for electrospinning.
5 is a graph comparing the productivity of polystyrene fibers when using a mixed solvent for electrospinning according to the present invention and when using a conventional solvent.

The embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art, and the following embodiments can be modified in various other forms, and the scope of the present invention is It is not limited to the following embodiments. Rather, these examples are provided to make the present disclosure more faithful and complete and to fully convey the spirit of the present invention to those skilled in the art.

The terminology used herein is used to describe a specific embodiment and is not intended to limit the present invention. As used herein, singular forms may include plural forms unless the context clearly indicates otherwise. Also, as used herein, “and/or” includes any combination of any one or more of the listed items.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing embodiments of the present invention.

1 is a reference diagram illustrating device components for producing an electrospun polystyrene fiber according to the present invention.

Referring to Figure 1, the device components for the production of polystyrene fibers are a fiber solution sprayer 10 for spraying a polystyrene solution dissolved by an electrospinning mixed solvent, a spray nozzle 20 connected to the fiber solution sprayer 10, It includes a fiber collector 30 for collecting the polystyrene fibers (PF) formed by injection from the injection nozzle 20, and a voltage supply 40 for applying a voltage between the injection nozzle 20 and the fiber collector 30 .

The electrospinning method is a method of manufacturing fibers by spinning a solution of a substance, which is a material for fibers, by electrical force and collecting the fibers in a collection device. It is relatively inexpensive and easy to obtain small diameter fibers through electrospinning. However. Despite the convenience of the electrospinning method, the result is greatly affected by various electrospinning conditions such as temperature, humidity, and voltage, and this is a major obstacle in the production of uniform quality fibers. Factors affecting electrospinning include temperature, humidity, voltage, diameter of spray nozzle, distance between spray nozzle and fiber collector (TCD), solution polarity, solution concentration, boiling point of solution, viscosity of solution, solution injection Speed, etc. Among these, the electrospinning mixed solvent to be used for electrospinning must have a polarity of a certain level or higher to be able to spin by applying electrical force, and the proper selection of the electrospinning mixed solvent acts as a very important factor in the productivity of polystyrene fiber. .

Figure 2 is a flow chart of an embodiment for explaining a method for producing polystyrene fiber using electrospinning according to the present invention.

First, polystyrene is dissolved using an electrospinning mixed solvent in which cyclohexanone and ethyl acetate are mixed (step S100).

Polystyrene is a vinyl-based general-purpose polymer of a thermoplastic resin, and has a colorless and transparent property and solubility in a wide range of organic solvents, and is widely used for industrial industry. When electrospinning using a different type of solvent, polystyrene can be confirmed that the shape of the manufactured fiber depends on the boiling point and dipole moment of the solvent.

On the other hand, the cyclohexanone and ethyl acetate used in the present invention have little toxicity to the human body compared to DMF and THF having human body risk. Cyclohexanone is a substance with very low oral toxicity, and ethyl acetate showed no sub-toxicity up to 1500 mg/L through animal experiments, and no neurotoxicity. According to this, cyclohexanone and ethyl acetate have a NFPA 704 Health hazard class of 1, which is a substance that poses little or little risk even when exposed to the human body.

However, the conventional electrospinning conditions for producing polystyrene fibers of the electrospinning method using DMF and THF can be set relatively easily, whereas when cyclohexanone and ethyl acetate are used as solvents, it is very difficult to set the electrospinning conditions. it's difficult.

Therefore, in order to manufacture polystyrene fibers using an electrospinning mixed solvent mixed with cyclohexanone and ethyl acetate, the composition ratio of the electrospun mixed solvent and polystyrene determines productivity for high quality polystyrene fibers.

Accordingly, the weight composition ratio of the electrospinning mixture solvent and polystyrene for dissolving the polystyrene according to the present invention in the electrospinning mixture solvent, the electrospinning mixture solvent: polystyrene = 70 [%] to 80 [%]: 20 [ %] to 30[%]. Particularly, when the weight composition ratio of the mixed solvent for electrospinning and polystyrene is equal to the mixed solvent for electrospinning: polystyrene = 75 [%]: 25 [%], the conditions for generating optimal polystyrene fibers are satisfied. The weight composition ratio between the mixed solvent of the electrospinning agent and the polystyrene is preferably a weight composition ratio such that the viscosity of the polystyrene solution is maintained in the range of 1500 [mPA-s] to 2500 [mPA-s]. The main characteristics related to the quality and productivity of the polystyrene fiber according to the weight composition ratio of the mixed solvent of the electrospinning agent and the polystyrene can be confirmed through an experimental example described later.

Meanwhile, the ratio of cyclohexanone and ethyl acetate constituting the mixed solvent for electrospinning should also be determined. The weight composition ratio between cyclohexanone and ethyl acetate for increasing productivity may be a ratio of cyclohexanone: ethyl acetate = 40 [%] to 60 [%]: 40 [%] to 60 [%]. In particular, when the weight composition ratio of cyclohexanone and ethyl acetate is cyclohexanone: ethyl acetate = 50 [%]: 50 [%], conditions satisfying the optimum polystyrene fiber are satisfied. Again, the weight composition ratio between cyclohexanone and ethyl acetate can be adjusted so that the viscosity of the polystyrene solution described above is 1500 [mPA-s] to 2500 [mPA-s]. Key characteristics related to the quality and productivity of the polystyrene fiber according to the weight composition ratio between cyclohexanone and ethyl acetate can also be confirmed through experimental examples described below.

After step S100, a polystyrene fiber is generated by applying a high voltage current in the process of spraying a polystyrene solution in which the polystyrene is dissolved in the electrospinning mixed solvent through a spray nozzle (step S110).

In the step of generating the polystyrene fiber, the temperature of the space in which the polystyrene solution is injected through the injection nozzle is maintained at 25[°C] to 30[°C]. When the temperature of the injection space is maintained at 25 [°C] to 30 [°C], polystyrene fibers having a certain quality or higher can be manufactured with a certain productivity or higher. When the temperature of the spraying space is out of the range of 25 [°C] to 30 [°C], the quality of the polystyrene fiber is deteriorated, and the productivity of the polystyrene falls rapidly.

In addition, in the step of generating the polystyrene fiber, the humidity of the space for spraying the polystyrene solution through the spray nozzle is maintained at 45 [%] to 55 [%]. When the humidity of the spraying space is maintained at 45 [%] to 55 [%], polystyrene fibers having a certain quality or higher can be manufactured with a certain productivity or higher. When the humidity of the spraying space is outside the range of 45 [%] to 55 [%], the quality of the polystyrene fiber is deteriorated, and the productivity of the polystyrene falls rapidly.

In addition, in the step of generating the polystyrene fiber, the diameter of the spray nozzle to which the polystyrene solution is sprayed is 0.25 [mm]. When the diameter of the spray nozzle is 0.25 [mm], polystyrene fibers having a certain quality or higher can be manufactured with a certain productivity or higher.

Hereinafter, an experimental example based on the determination of the composition ratio of the electrospinning mixed solvent and polystyrene for the production of the polystyrene fiber and the environmental conditions for the production of the polystyrene fiber will be described.

1. Determination of the weight composition ratio of the mixed solvent and polystyrene for electrospinning

The ethyl acetate used as one of the mixed solvents for electrospinning in the present invention has a very low boiling point of 77.1° C., and a solution in which polystyrene is dissolved in ethyl acetate has a relatively low viscosity.

If the boiling point of the polystyrene solution is too low, all of the ethyl acetate solvent evaporates while the solution is spun from the spray nozzle, causing clogging in the spray nozzle, which may lead to a decrease in productivity.

In addition, if the viscosity of the polystyrene solution is too low, it is difficult to produce a small diameter fiber, and a bead in the middle of the fiber may occur.

On the other hand, the cyclohexanone used as one of the mixed solvents for another electrospinning in the present invention has a relatively high boiling point of 155.65 [°C], and a solution of polystyrene dissolved in cyclohexanone has a relatively high viscosity.

When the boiling point of the polystyrene solution is too high, the cyclohexanone solvent does not evaporate even after the fibers are collected in the fiber collector, so that the collected fibers may melt and entangle.

In addition, if the viscosity of the polystyrene solution is too high, bead-like nodules may occur in the middle of the fiber.

Therefore, by using a mixed solvent according to a certain ratio of ethyl acetate and cyclohexanone as a mixed solvent for electrospinning in electrospinning, the viscosity and boiling point of a solution having a great influence on the result of electrospinning can be appropriately adjusted.

3 is a graph illustrating a change in solution viscosity according to the composition ratio between a mixed solvent for electrospinning and polystyrene.

Figure 3 is different from the weight composition ratio of ethyl acetate and cyclohexanone of the mixed solvent for electrospinning, when preparing a polystyrene solution having a weight composition ratio of 20, 25, and 30 [%], respectively, compared to the mixed solvent for electrospinning Shows the change in solution viscosity.

As shown in FIG. 3, the weight composition ratio of polystyrene increases and the proportion of cyclohexanone increases, and thus a trend of increasing viscosity can be confirmed. In particular, it can be seen that the viscosity increases exponentially (for example, 3000 [mPa-s] or more) as the proportion of cyclohexanone increases when the polystyrene weight composition ratio is 30 [%].

In addition, when the weight composition ratio of polystyrene is 20 [%], it can be confirmed that the viscosity of the mixed solvent of cyclohexanone and ethyl acetate in all proportions is very low (1000 [mPa-s] or less), and thus is not suitable for spinning. When the polystyrene solution is electrospun, the fiber is well formed when the solution viscosity is in the range of 1500-2500 mPa-s.

On the other hand, when the composition ratio of polystyrene is 25 [%], the viscosity of the polystyrene solution corresponds to 1518 to 2423 [mPa-s] depending on the weight composition ratio between cyclohexanone and ethyl acetate. When the polystyrene solution is electrospinned, the fibers are well formed when the solution viscosity is in the range of 1500-2500 [mPa-s], so that the electrospinning is performed by setting the weight composition ratio of the polystyrene with the mixed solvent to 25[%]. It is appropriate.

2. Environmental conditions for electrospinning of polystyrene solutions using mixed solvents for electrospinning

When spraying a polystyrene solution having a weight composition ratio of 75% [%]: 25% [%] of the mixed solvent of the electrospinning agent through a spray nozzle, a voltage of 12 [kV] is applied as a high voltage current. The distance between the fiber collectors was 15 [cm], and the inflow rate of the polystyrene solution was 1.0 [mL/hour] to perform electrospinning.

At this time, the optimum electrospinning temperature is 25 to 30 [℃], and the humidity is 45 to 55 [%], and when the temperature and humidity are outside this range, clogging increases or the mixed solvent for electrospinning is not sufficiently volatilized. Because the spinning is not smooth, the fiber state of the polystyrene fibers collected in the fiber collector does not take the form of fibers.

The diameter of the spray nozzle is divided into 0.25 [mm], 0.50 [mm], and 0.71 [mm], respectively, and the change in the electrospinning fiber according to the diameter change is confirmed. At this time, the solvent mixing ratio of the mixed solvent for electrospinning is different between cyclohexanone and ethyl acetate, and cyclohexanone/ethyl acetate = 3/1, 2/1, 1/1, 1/2, 1/3, respectively. Spinning is performed. In addition, the results are compared by performing electrospinning even under a single solvent condition of cyclohexanone and ethyl acetate, not a mixed solvent for electrospinning.

Table 1 below is table information for comparing the clogging phenomenon according to the weight composition ratio of cyclohexanone and ethyl acetate.

Composition ratio between ethyl acetate (E) and cyclohexanone (C) only E E:C=3:1 E:C=2:1 E:C=1:1 E:C=1:2 E:C=1:3 only C Spray nozzle
diameter 0.25
[mm] Clogging occurs within 1~2[min] Clogging occurs within 1~2[min] Clogging occurs within 5 to 10 minutes No clogging No clogging No clogging No clogging 0.50
[mm] Clogging occurs within 1~2[min] Clogging occurs within 1~2[min] Clogging occurs within 5~10[min] Clogging occurs within 30 [min] No clogging No clogging No clogging 0.71
[mm] Clogging occurs within 1~2[min] Clogging occurs within 1~2[min] Clogging occurs within 1~2[min] Clogging occurs within 5 to 10 minutes No clogging No clogging No clogging

According to Table 1, due to the low boiling point of ethyl acetate, the higher the weight composition ratio of ethyl acetate, the more the tendency of clogging can be confirmed. In addition, it can be confirmed that the larger the diameter of the injection nozzle, the more the clogging gradually increased. Accordingly, the clogging phenomenon can be lowered by mixing cyclohexanone with ethyl acetate.

Figure 4 is a reference diagram illustrating a polystyrene fiber produced using a mixed solvent of electrospinning cyclohexanone and ethyl acetate.

Referring to FIG. 4, the higher the proportion of ethyl acetate was, the more uniform the polystyrene fibers were produced. have. Also, when the ratio of cyclohexanone is high, nodules may be found in the middle of the fibers.

According to this, it is possible to maintain the quality of the polystyrene fiber by making the weight composition ratio of cyclohexanone and ethyl acetate equivalent. That is, it can be seen that it is most advantageous for polystyrene electrospun fibers to prepare a mixed solvent with a weight composition ratio of cyclohexanone and ethyl acetate of about 1:1.

Table 2 below is table information for comparing the diameter (unit: μm) of polystyrene fibers produced using a mixed solvent of cyclohexanone and ethyl acetate for electrospinning.

Composition ratio between ethyl acetate (E) and cyclohexanone (C) only E E:C=3:1 E:C=2:1 E:C=1:1 E:C=1:2 E:C=1:3 only C Spray nozzle
diameter 0.25
[mm] 6.20±1.57 5.42±1.03 3.50±1.32 3.83±0.56 0.50
[mm] 6.07±1.47 5.94±1.36 4.80±0.84 4.61±1.25 0.71
[mm] 6.02±2.27 6.13±1.40 5.16±1.34 5.29±2.10

According to Table 2, when the ratio of cyclohexanone to ethyl acetate is 2 times or more, the diameter of the fibers cannot be measured because the fibers are crushed. Thus, the fibrous form is ethyl acetate (E): cyclohexanone (C) = 3:1 to 1:1 is suitable for electrospinning.

It can be seen that the higher the proportion of cyclohexanone, and the smaller the diameter of the spray nozzle, the smaller the diameter of the fibers. Therefore, considering the specific surface area of the fiber, it can be said that the optimum condition is when the ratio of cyclohexanone to ethyl acetate is 1:1 and the diameter of the spray nozzle is 0.25 mm.

5 is a graph comparing the productivity of polystyrene fibers when using a mixed solvent for electrospinning according to the present invention and when using a conventional solvent.

Here, productivity means the amount of polystyrene fibers produced per hour. Referring to FIG. 5, polystyrene fiber productivity using an electrospinning mixed solvent in which cyclohexanone and ethyl acetate are mixed according to the present invention is a conventional solvent (for example, acetone and DMF mixed solvent, DMF and THF) It can be seen that a mixed solvent or a mixed solvent of DMAc (dimethylacetamide) and DMF) exhibits a productivity of 2 to 3 times higher than that of polystyrene fiber.

As described above, the embodiments of the present invention have been described, but the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be interpreted by the following claims, and all technologies within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (9)

Dissolving polystyrene using an electrospinning mixed solvent in which cyclohexanone and ethyl acetate are mixed; And
Generating a polystyrene fiber by applying a high voltage current in the process of spraying a polystyrene solution in which the polystyrene is dissolved in the electrospinning mixed solvent through a spray nozzle,
The polystyrene solution,
The electrospinning mixed solvent: the polystyrene = 75 [%]: has a weight composition ratio of 25 [%] and a solution viscosity of 1518 [mPA-s] to 2423 [mPA-s],
The cyclohexanone: the ethyl acetate = 50[%]: 50[%] has a weight composition ratio so that the diameter of the spray nozzle to which the polystyrene solution is sprayed corresponds to 0.25[mm] in consideration of the specific surface area of the polystyrene fiber. Polystyrene fiber manufacturing method using an electrospinning, characterized in that. delete delete delete delete delete The method according to claim 1,
The step of producing the polystyrene fiber,
A method of manufacturing polystyrene fiber using electrospinning, characterized in that the temperature of the space for spraying the polystyrene solution through the spray nozzle is 25[°C] to 30[°C]. The method according to claim 1,
The step of producing the polystyrene fiber,
The polystyrene fiber manufacturing method using electrospinning, characterized in that the humidity of the space for spraying the polystyrene solution through the injection nozzle is 45 [%] to 55 [%].

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