KR20120124594A - Organic/inorganic hybrid polysilsesquioxane microfiber using electrospinning, and the method for preparing the same - Google Patents

Abstract

PURPOSE: A polysilsesquioxane microfiber of a ladder type using electrospinning and a method for fabricating the same are provided to ensure excellent thermal resistance and chemical resistance. CONSTITUTION: A polysilsequioxane microfiber of a ladder type contains polysilsesquioxane of chemical formula 1. In chemical formula 1, R is selected from the group consisting of organic functional groups. The polysilsesquioxane is denoted by chemical formula 2 or 3. The thickness of the microfiber is 1-10 um. A method for fabricating the microfiber comprises a step of electrospinning a solution containing polysilsesquioxane and a step of irradiating UV ray. A solvent used in the solution is tetrahydrofurane, dimethyl formamide, dimehtyl acetamide, N-methyl-2-pyrrolidone, hexane, cyclohexane, toluene, xylene, cresol, chloroform, dimethyl benzene, trimethyl benzene, pyridine, methyl naphthalene, nitromethane, acrnitrile, methylene chloride, aniline, dimethyl sulfoxide, or benzyl alcohol.

Description

Organic-inorganic hybrid polysilsesquioxane microfibers using electrospinning and its manufacturing method {ORGANIC / INORGANIC HYBRID POLYSILSESQUIOXANE MICROFIBER USING ELECTROSPINNING, AND THE METHOD FOR PREPARING THE SAME}

The present invention relates to an organic-inorganic hybrid polysilsesquioxane microfibers using electrospinning and a method of manufacturing the same.

Electrospinning is a method that can easily produce continuous fibers of several micrometers or less in diameter. Such electrospinning can be applied to synthetic fibers, natural fibers, chromophores, nanoparticles, active additives, as well as polymers with metals and semiconductor oxides, and thus can produce fibers having a composite structure such as core-shell fibers or hollow fibers. have. In particular, much research has been done in the field of biomaterials and electronic materials. Such composite fibers can be manufactured from short fibers to aligned fibers, and can be applied to a wide range of fields such as light conversion technology, sensing technology, catalysts, filters, and medical care.

However, the technical limitations of the raw materials are obstacles to large-scale commercialization. In particular, there is a problem that the fibers produced when the electrospinning alone in the organic system can not withstand high temperatures.

In order to compensate for these points, there has been an example of the recent application of electrospinning using metal oxides. However, the metal oxide addition techniques as described above are far from obtaining a emitter of a certain shape and thickness since the final purpose is to use the nanoparticle form obtained after high temperature carbonization, rather than directly using the manufactured fiber. .

In addition, since the electrospinning of the organic polymer alone does not form a chemical resistance unless it undergoes a curing process after spinning, it is currently commercialized by being limited to a material processing method in a bio field requiring spontaneous biodegradation. Accordingly, in the field of electrospinning materials, the necessity of an organic-inorganic hybridization material in which both organic functionalities and inorganic stable properties are harmonized is emerging.

An object of the present invention is to provide a ladder-type polysilsesquioxane microfibers having excellent chemical resistance and heat resistance at a constant thickness by electrospinning a solution containing ladder-type polysilsesquioxane, and a method of manufacturing the same.

In order to solve the above object, the present invention provides a ladder-type polysilsesquioxane microfiber comprising a ladder-type polysilsesquioxane represented by the following formula (1).

≪ Formula 1 >

(In the formula 1,

Each R is independently selected from the group consisting of organic functional groups, each R is the same or different from each other, and n is an integer from 1 to 10,000.)

In one embodiment of the present invention, each R is independently an organic group having 1 to 30 carbon atoms selected from the group consisting of alkyl, aryl, vinyl, epoxy, amine, halogen, alkylhalogen, methacryl and acryl groups It may be a functional group.

In one embodiment of the present invention, the thickness of the ladder-type polysilsesquioxane microfibers may be 1 to 10㎛.

In addition, the present invention provides a method for producing a ladder-type polysilsesquioxane microfibers, including; electrospinning a solution containing a ladder-type polysilsesquioxane represented by the following formula (1).

≪ Formula 1 >

(In the formula 1,

Each R is independently selected from the group consisting of organic functional groups, each R is the same or different from each other, and n is an integer from 1 to 10,000.)

In one embodiment of the present invention, irradiating ultraviolet rays after the electrospinning; may further include.

In one embodiment of the present invention, the solvent used in the solution is tetrahydrofuran, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, cyclohexane, toluene, xylene, cresol, It may be selected from the group consisting of chloroform, thichlorobenzene, dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, methylene chloride, octadecylamine, aniline, dimethyl sulfoxide and benzyl alcohol.

In one embodiment of the present invention, the electrospinning may be performed at a voltage of 8 to 18KV and a discharge rate of 10ul / min.

According to the present invention, the silsesquioxane alone can be electrospun, and thus the manufacturing method is simple, and the ladder-type polysilsesquioxane microfibers using the electrospinning solution can maintain fibers at a high temperature while maintaining a constant form of the spun fiber. Not only can be manufactured by the process, but also photocuring or thermal curing can be easily performed depending on the type of organic functional group introduced into the silsesquioxane main chain after spinning, and can be utilized in many applications.

Figure 1 shows the ¹ H NMR analysis of the ladder-type polysilsesquioxane according to an embodiment of the present invention.
Figure 2 shows the ²⁹ Si NMR analysis of the ladder-type polysilsesquioxane according to an embodiment of the present invention.
3 is an SEM image ((a) 200 ×, (b) 5000 ×) of an electrospun ladder-type polysilsesquioxane microfiber according to an embodiment of the present invention.
Figure 4 is a SEM photograph ((a) 3000 ×, (b) 5000 ×) of the electrospinning and UV-cured ladder-type polysilsesquioxane microfibers according to an embodiment of the present invention.
Figure 5 is a SEM photograph ((a) 3000 ×, (b) 5000 ×) after the chemical resistance test of the ladder-type polysilsesquioxane microfibers according to an embodiment of the present invention.
Figure 6 is a graph measuring the thermal decomposition stability through TGA after the chemical resistance test of the ladder-type polysilsesquioxane microfibers according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail in order to facilitate the present invention by those skilled in the art.

The present invention provides a ladder-type polysilsesquioxane microfibers comprising a ladder-type polysilsesquioxane represented by the following formula (1).

≪ Formula 1 >

In Formula 1, each R is independently selected from the group consisting of organic functional groups, n is an integer of 1 to 10,000. R may be the same or different and may form a copolymer.

More specifically, the ladder-type polysilsesquioxane may be represented by the following formula (2) or (3).

<Formula 2>

<Formula 3>

In the above, R ₁ and R ₂ are each independently selected from the group consisting of organic functional groups, n is an integer from 1 to 10,000. R ₁ and R ₂ may form a copolymer.

Preferably, R, R ₁ and R ₂ are each independently an organic group having 1 to 30 carbon atoms selected from the group consisting of alkyl, aryl, vinyl, epoxy, amine, halogen, alkylhalogen, methacryl and acryl groups It may be a functional group. For example, more preferably the R ₁ and R ₂ One may be propyloxymethacyl, and the other may be phenyl.

In the present invention, the "alkyl group" is a C1-C30 side chain or crushed alkyl group, such as a methyl group, an ethyl group, a propyl group, isopropyl group, a butyl group, an isobutyl group, t-butyl group, and is cyclopropyl group, cyclo And a cycloalkyl group having 3 to 10 carbon atoms such as a pentyl group and a cyclohexyl group.

In the present invention, the "aryl group" is also represented by -Ar, and includes a phenyl group, anthryl group, phenanthryl group and the like.

In the present invention, the 'vinyl group' is a functional group represented by CH ₂ = CH-, and includes vinyl chloride, vinyl acetate, acrylic acid, styrene and the like.

In the present invention, the "alkylhalogen" is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and examples of the halogen atoms include fluorine atom, chlorine atom, bromine atom and iodine atom.

In the polysilsesquioxane compound represented by Formula 1, when R is different from each other, each may have a molar ratio of 1: 9 to 9: 1. Preferably, it may be 6: 4 or 4: 6, but is not necessarily limited thereto, and may be adjusted to various molar ratios within the above ranges according to needs of physical properties.

Ladder type polysilsesquioxane represented by the formula (1) has a regular ladder structure (LPSQ, ladder type polysilsesquioxane), it may be a homopolymer or a copolymer.

In the case of cage silsesquioxane (POSS, polyhedral silsesquioxane), since it is a low molecular form and has crystallinity, physical properties are deteriorated and practical application to industrial applications is difficult. Unlike cage silsesquioxane, however, ladder silsesquioxane is composed of continuous chains of high rich and not only structurally stable, but also has high thermal stability and high compatibility with organic solvents. It has advantages as an inorganic composite material.

The fiber comprising such a ladder-type polysilsesquioxane maintains a constant thickness and shape and has excellent chemical resistance and has stable physical properties that can withstand high temperatures.

The ladder polysilsesquioxane microfibers may have a thickness of 1 to 10 μm, preferably 1 to 4 μm, but are not necessarily limited thereto. When the thickness of the fiber is within the above range, it can be easily applied to a functional catalyst requiring a large surface area and functionality, and can be used as a substitute for glass fibers requiring extreme physical properties.

In order to prepare a ladder-like polysilsesquioxane microfibers as described above, the present invention comprises electrospinning a solution containing a ladder-type polysilsesquioxane represented by the following formula (1); Provided is a method for producing silsesquioxane microfibers.

&Lt; Formula 1 >

In Formula 1, each R is independently selected from the group consisting of organic functional groups, n is an integer of 1 to 10,000. R may be the same or different and may form a copolymer.

More specifically, the ladder-type polysilsesquioxane may be represented by the following formula (2) or (3).

<Formula 2>

<Formula 3>

In the above, R ₁ and R ₂ are each independently selected from the group consisting of organic functional groups, n is an integer from 1 to 10,000. R ₁ and R ₂ may form a copolymer.

Preferably, R, R ₁ and R ₂ are each independently an organic group having 1 to 30 carbon atoms selected from the group consisting of alkyl, aryl, vinyl, epoxy, amine, halogen, alkylhalogen, methacryl and acryl groups It may be a functional group. For example, more preferably the R ₁ and R ₂ One may be propyloxymethacyl, and the other may be phenyl.

The method for preparing the ladder-type polysilsesquioxane compound is not particularly limited, but preferably, a water-containing organic solution containing a trialcohol siloxane monomer, an organic solvent, water and a catalyst is prepared, and the organic in the water-containing organic solution is prepared. Methods of controlling the amount or water content of the solvent can be used to selectively synthesize from other structures efficiently. When the R of the synthesized ladder polysilsesquioxanes is different, each may have a molar ratio of 1: 9 to 9: 1 as described above. Preferably it may be 6: 4 or 4: 6, but is not necessarily limited thereto.

After preparing a ladder-type polysilsesquioxane compound, it is added to a solvent to prepare a mixed solution. The solvent is alcohol, ketone, as well as tetrahydrofuran, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, cyclohexane, toluene, xylene, cresol, chloroform, thichlorobenzene , Dimethylbenzene, trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, methylene chloride, octadecylamine, aniline, dimethyl sulfoxide and benzyl alcohol, but the compound is dissolved The solvent is not particularly limited. Preferably dimethylformamide.

The fiber is obtained by electrospinning using the prepared mixed solution. Electrospinning is preferably performed at a voltage of 8 to 18 KV and a discharge rate of 5 to 15 µl / min, but is not limited thereto. If the voltage is less than 8KV, agglomeration may occur during fiber spinning, and if the voltage is higher than 18KV, the fiber may be broken. In addition, if the discharge rate is less than 5㎛ / minute may induce a fine shape of the fiber, but may cause a drop phenomenon, if larger than 15㎛ / minute it may be difficult to form a fiber due to agglomerates of 10㎛ or more

As can be seen in Figure 3, the fiber obtained by using the electrospinning in the above method, the thickness is constant to 10㎛ or less, especially 4㎛ or less and the surface is smooth. That is, according to the production method of the present invention, it is possible to produce fine fibers by electrospinning using only the ladder-type polysilsesquioxane.

The manufacturing method of the present invention may further include irradiating ultraviolet rays to the ladder-type polysilsesquioxane microfibers produced by electrospinning as described above. Ultraviolet light uses a long wavelength of 340 to 380 nm, preferably 360 nm, and the amount of light is preferably about 1 J / cm 2 or more. Organic functional groups included in the ladder-type polysilsesquioxane of the present invention are photocured by ultraviolet rays.

The fiber is cured by the ultraviolet irradiation can be obtained the effect of maximizing the chemical resistance. When photocuring by ultraviolet irradiation, the fiber according to the present invention is maintained without its deformation due to shrinkage. This can be confirmed in Example 2 to be described later.

Ladder-type polysilsesquioxane microfibers of the present invention is achieved by the electrospinning of ladder-type polysilsesquioxane alone, and is easy to manufacture, and excellent in heat resistance and chemical resistance, and thus may be usefully used in various fields.

The present invention is described in more detail through the following implementation. However, the examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

[ Example  One]

1-1. Ladder Polysilsesquioxane  Synthesis of compounds

As a ladder polysilsesquioxane, ladder-like polyacyloxypropyl-co-phenyl silsesquioxane (LPAPSQ) was synthesized.

First, 3-acryloxypropyl trimethoxy silane (0.16 mol) and phenyl trimethoxy silane (0.24 mol) are prepared as trialkoxy monomers, and then the aqueous solution is purified with HPLC grade tetrahydrofuran (400 g) and distilled water (240 g). After the preparation, the base catalyst was added dropwise to the aqueous solution prepared in advance, and the pH was adjusted to 11 and stirred.

After completion of the addition, the reaction proceeded and the sequential increase in molecular weight was confirmed. The completion point of the polymerization was completed based on the point at which molecular weight does not increase through GPC, and this time point was confirmed to coincide with the point where the boundary divided into layers is clearly seen. As a purification method of the polymer, it refine | purified by the method of fractional distillation using methylene chloride.

¹ H NMR spectral data of the copolymer thus obtained are shown in FIG. 1. As a result of the analysis of FIG. 1, it was confirmed that 3-acryloxypropyl trimethoxy silane (0.16 mol) and phenyl trimethoxy silane (0.24 mol) were polymerized exactly at a molar ratio of 6: 4. The molecular weight (Mw) was 38,000 (based on polystyrene).

Formula 1 of R ₁ (3-acryloxypropyl trimethoxy silane) and R ₂ (phenyl trimethoxy silane) of Example 1

<Formula 3> Formula of polyacyloxypropyl-co-phenyl silsesquioxane synthesized in Example 1-1

<Formula 4> Formula of the polyacyloxypropyl-co-phenyl silsesquioxane synthesized in Example 1-1

1-2.  Electrospinning Ladder Polysilsesquioxane  Fine fiber manufacturing

A fiber including polyacyloxypropyl-co-phenyl silsesquioxane synthesized in 1-1 was prepared.

First, a mixed solution for preparing a stable electrospun fiber was prepared. 30 g of dimethylformamide was prepared as a solvent, and 70 g of LPAPSQ obtained in 1-1 was added to the prepared solvent, followed by stirring with a mechanical stirring device for 4 hours. After stirring, foreign substances such as dust were removed through a 1 μm pore-size filter.

Electrospinning was performed using the prepared mixed solution. The rate of electrospinning was controlled at a rate of 10 μm / min, and the amount of voltage used was 10 KV. At this time, the temperature was adjusted to 22 ℃ and the fiber was obtained on aluminum foil. The result of observing the obtained fiber through SEM is shown in FIG. 3. As can be seen in Figure 3, it can be seen that a fiber of a constant thickness of 1 ~ 4㎛ size was obtained.

[ Example  2]

After the fiber was prepared in the same manner as in Example 1, ultraviolet rays were further irradiated by irradiation with ultraviolet rays. UV conditions were set based on a long wavelength of 360nm, the light amount was cured by adjusting to 1J / ㎠.

The result of observing the obtained fiber through SEM is shown in FIG. 4. As can be seen in Figure 4, the shrinkage due to the hardening of the fiber was not found, it was possible to observe a spinning fiber of a constant shape well maintained.

[Example 1] Chemical resistance tests

1-1. SEM  Photo shoot

A chemical resistance test was conducted on the spun fiber obtained in Example 2 above. In the chemical resistance test, LPAPSQ fibers after spinning and UV curing were immersed in dimethylformamide, tetrahydrofuran, methylene chloride, chloroform, and toluene for 30 seconds, respectively, and the shape of the spinning fibers was observed through SEM. This is shown in FIG. 5. As can be seen in Figure 5, the ladder-like polysilsesquioxane microfibers according to the embodiment of the present invention can be seen that the shape is maintained even after the chemical resistance test, it was confirmed that it has excellent chemical resistance.

1-2. Thermal analysis  Experiment

For the spinning fiber obtained in Example 2, a thermal analysis experiment using a TGA was carried out, and this is shown in FIG. As can be seen in Figure 6, the ladder-like polysilsesquioxane microfibers according to the embodiment of the present invention was analyzed to have a high pyrolysis temperature stable up to 400 ℃ even if a weak functional group is substituted for heat such as methacryl group.

Claims (15)

Ladder-type polysilsesquioxane microfibers comprising a ladder-type polysilsesquioxane represented by the following formula (1).
&Lt; Formula 1 >

(In Formula 1,
Each R is independently selected from the group consisting of organic functional groups, each R is the same or different from each other, and n is an integer from 1 to 10,000.)
The method of claim 1,
The ladder polysilsesquioxane is a ladder-type polysilsesquioxane microfibers represented by the following formula (2).
(2)

(In the formula (2)
R ₁ and R ₂ are each independently selected from the group consisting of organic functional groups, n is an integer from 1 to 10,000.)
The method of claim 1,
The ladder-type polysilsesquioxane is a ladder-type polysilsesquioxane microfibers represented by the following formula (3).
(3)

(In Chemical Formula 3,
R ₁ and R ₂ are each independently selected from the group consisting of organic functional groups, n is an integer from 1 to 10,000.)
4. The method according to any one of claims 1 to 3,
R, R ₁ and R ₂ are each independently an organic group having 1 to 30 carbon atoms selected from the group consisting of alkyl, aryl, vinyl, epoxy, amine, halogen, alkylhalogen, methacryl and acryl groups Type polysilsesquioxane microfibers.
The method of claim 4, wherein
R ₁ and R ₂ One is propyloxymethacyl (propyloxymethacyl), the other is phenyl (phenyl) ladder type polysilsesquioxane microfibers.
The method of claim 1,
The ladder-type polysilsesquioxane microfibers have a thickness of 1 to 10 µm.
To electrospin the solution containing the ladder-type polysilsesquioxane represented by the following formula (1).
&Lt; Formula 1 >

(In Formula 1,
Each R is independently selected from the group consisting of organic functional groups, each R is the same or different from each other, and n is an integer from 1 to 10,000.)
8. The method of claim 7,
The ladder polysilsesquioxane is a method for producing a ladder-type polysilsesquioxane microfibers represented by the following formula (2).
(2)

(In the formula (2)
R ₁ and R ₂ are each independently selected from the group consisting of organic functional groups, n is an integer from 1 to 10,000.)
8. The method of claim 7,
The ladder polysilsesquioxane is a method of producing a ladder-type polysilsesquioxane microfibers represented by the following formula (3).
(3)

(In Chemical Formula 3,
R ₁ and R ₂ are each independently selected from the group consisting of organic functional groups, n is an integer from 1 to 10,000.)
8. The method of claim 7,
The method of manufacturing a ladder-type polysilsesquioxane microfibers further comprising; irradiating ultraviolet rays after the electrospinning.
The method according to any one of claims 7 to 9,
R, R ₁ and R ₂ are each independently an organic group having 1 to 30 carbon atoms selected from the group consisting of alkyl, aryl, vinyl, epoxy, amine, halogen, alkylhalogen, methacryl and acryl groups Method for producing polysilsesquioxane microfibers.
12. The method of claim 11,
R ₁ and R ₂ One is propyloxymethacyl (propyloxymethacyl), the other is phenyl (phenyl) method for producing a ladder-type polysilsesquioxane microfibers.
8. The method of claim 7,
The solvent used in the solution is tetrahydrofuran, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, hexane, cyclohexane, toluene, xylene, cresol, chloroform, thichlorobenzene, dimethylbenzene, Preparation of ladder type polysilsesquioxane microfibers selected from the group consisting of trimethylbenzene, pyridine, methylnaphthalene, nitromethane, acrylonitrile, methylene chloride, octadecylamine, aniline, dimethylsulfoxide and benzyl alcohol Way.
8. The method of claim 7,
The electrospinning is a method of producing a ladder-type polysilsesquioxane microfibers, which is performed at a voltage of 8 to 18KV and a discharge rate of 5 to 15 mu l / min.
8. The method of claim 7,
The ladder-type polysilsesquioxane microfibers have a thickness of 1 to 10 μm.

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