KR20110116879A - Polyaniline doped by sulfonated polyphenylsilsesquioxane with high stability of electrical conductivity and menufacturing method of the same - Google Patents

Abstract

The present invention relates to a conductive polyaniline doped with sulfonated PolyPenylSilsesQuioxane (S-PPSQ) and a process for the preparation thereof. Due to the doping of the sulfonated polyphenylsilsesquioxane, the conductivity is higher and the heat resistance is higher than that of general polyaniline.
The polyaniline may be prepared by dissolving polyaniline and sulfonated polyphenylsilsesquioxane in an organic solvent and then stirring.

Description

Polyaniline Doped by Sulfonated Polyphenylsilsesquioxane with High Stability of Electrical Conductivity And Menufacturing Method Of The Same}

The present invention relates to a polyaniline which is a conductive plastic having excellent electrical conductivity and heat resistance.

Conductive plastics are polymers known to the general public when A. J. Heeger and A. G. MacDiarmid of the United States and H. Shirakawa of Japan received the Nobel Prize in Chemistry in 2000. They first reported in 1977 that polyacetylene polymers pass electricity through a process called doping. Since then, research on conductive plastics has been very active.

Conductive polymers are often referred to as fourth-generation plastics, and their feature is that the role of plastics is no longer passive, such as insulators, but active, like organic semiconductors.

According to the conductivity, the conductive polymer may be 10 ^-13 to 10 ^-7 S / cm as antistatic materials, 10 ^-6 to 10 ^-2 S / cm as static discharge materials, 1 S / cm or more Is applied to EMI shielding materials or battery electrodes, semiconductors, or solar cells, and the conductivity value can be improved to enable much more diverse applications.

Therefore, the conductive polymers exhibit the electrical, magnetic, and optical properties of metals in addition to the excellent mechanical and processability inherent in the polymers. It is emerging as a large research subject in the field.

Important conductive polymers currently known are polyaniline, polypyrrole, polythiophene, poly (p-phenylene vinylene), polyparaphenylene (Poly (p-phenylene) ), And polyphenylene sulfide (PPS).

Among them, polyaniline has received the most attention due to its high stability in the air and easy industrialization, and it is expected to play an essential role in the production of important devices such as organic electroluminescent devices (OLEDs) and field effect transistors (FETs), which have revolutionized display in recent years. have.

Polyaniline is an organic polymer having an alternating ring heteroatom backbone structure, and its broad derivatives can be synthesized by substituting a benzene ring or a Nitrogen atom. According to the oxidation state, the partial oxidation type (y = 0.5) of the emeraldine base (Emeraldine Base) and the fully reduced form (y = 1.0) of the leuco-emeraldine base and complete oxidation type ( y = 0.0) and Pernigraniline Base.

Imine nitrogen atoms can be protonated in whole or in part by an aqueous solution of protonic acid, which results in emeraldine salts with different doping levels and simultaneously powder And electrical conductivity in both film forms is increased from 10 ⁻⁸ to 1-100 S / cm.

The method for synthesizing such polyaniline can be broadly divided into electrochemical method by electrically charge transfer reaction and chemical oxidation method by protonation through redox reaction or acid / base reaction. Chemical oxidation methods are known to be suitable when polyaniline is to be mass produced on an industrial scale.

As such, polyaniline is relatively easy to synthesize compared with other conductive polymers, and has the advantage of controlling electrical properties according to its oxidation state. The ability to change from emeraldine base (EB) to conductive emeraldine salt (ES) to replace traditional ITO in TFD-LCDs, simplify semiconductor circuit processing, ultrafast switches, Many applied researches, including nonlinear optical devices, are underway.

In particular, studies are being conducted to improve the electrical conductivity of polyaniline by doping a polyaniline with a large organic molecule such as dodecylbenzene sulfonic acid (DBSA) or camphorsulfonic acid (CSA). Doping techniques have been disclosed.

It shows high electrical conductivity after doping, as well as excellent thermal and atmospheric stability for both doped and undoped forms, which can be used as electrically conductive plastics, transparent conductors, electromagnetic shielding thin films, secondary batteries, electrochromic devices, and light emitting diodes. The polymer that can be developed is required.

An object of the present invention is to provide a conductive polyaniline excellent in electrical conductivity and heat resistance, and a method of manufacturing the same, and to utilize it in various fields such as antistatic, static elimination, electromagnetic shielding, batteries, electrode semiconductors, and solar cells.

The present invention provides a conductive polyaniline doped with sulfonated PolyPenylSilsesQuioxane (S-PPSQ) and a method of making the same. Due to the doping of the sulfonated polyphenylsilsesquioxane, the conductivity is higher and the heat resistance is higher than that of general polyaniline.

The polyaniline may be prepared by dissolving polyaniline and sulfonated polyphenylsilsesquioxane in an organic solvent and then stirring.

The polyaniline has high conductivity and high heat resistance compared to conventional conductive plastics, and thus can be used in various fields such as antistatic, static elimination, electromagnetic shielding, battery, electrode semiconductor, and solar cell. In addition, unlike conventional conductive plastics, as the temperature increases, the electrical conductivity becomes higher, and the mixture with the general conductive plastic, which becomes lower as the temperature increases, keeps the electrical conductivity according to the temperature change, thereby making it an ideal embedded capacitor. (embedded capacitor) or resistor can be manufactured.

1 is a graph of a spectrometer of PPSQ and S-PPSQ.
2 is a comparison of conductivity values of Examples 1-3.
3 is a graph comparing the TGA results of Example 1 and Comparative Example 1. FIG.
4 is a graph showing a comparison of conductivity changes between Example 1 and Comparative Example 1 at 120 ° C.
5 is a comparison graph of conductivity changes of Example 1 and Comparative Example 1 with time at 150 ° C.
6 is a graph of resistance with temperature of Example 1. FIG.
7 is a graph of resistance / thickness according to the temperature of Example 1. FIG.
8 is a graph showing a change in the resistance value according to the temperature of Example 1. FIG.

The present invention relates to conductive polyaniline doped with polyaniline with sulfonated PolyPenylSilsesQuioxane (S-PPSQ). The polyaniline of the present invention has higher electrical conductivity and heat resistance than conventional polyaniline.

Such improvement in conductivity and improvement in heat resistance can be found in the structure of the sulfonated polyphenylsilsesquioxane, which is a dopant. Since sulfonated polyphenylsilsesquioxane is solid and polyphenylsilsesquioxane having sulfone groups introduced therein, and has excellent heat resistance, even conventional dopants such as camphorsulfonic acid and paratoluenesulfonic acid may be used even when doping with the same sulfonic group. This is because the heat resistance is better than the heat. Since such a material is added as a dopant, it is possible to simultaneously obtain an effect of improving heat resistance while maintaining conductivity.

The sulfonated polyphenylsilsesquioxane is sulfonated polyphenylsilsesquioxane represented by the following formula (2).

In Formula 2 n is an integer of 5 to 20000.

The sulfonation degree of the sulfonated polyphenylsilsesquioxane is preferably 10 to 100%. In the present invention, the sulfonated degree means how much of the sulfone group is substituted in the total substituents in which the sulfone group may be substituted in the unit phenylsilsesquioxane. If the sulfonation degree is less than 10, there is a problem that the improvement of the electrical conductivity is weak due to the weak acid property.

An example of the sulfonated polyphenylsilsesquioxane may be represented by the following Chemical Formula 3.

In Formula 3, n is an integer of 5 to 20000.

The sulfone group may be substituted in the benzene ring of the polyphenylsilsesquioxane in various ways without limiting the number and position of the sulfone group in addition to the formula (3).

When the sulfonated benzene ring is acidic and the sulfonated benzene ring is non-acidic as shown in Formula 3, when the sulfonated polyphenylsilsesquioxane is doped, electrical conductivity is improved and heat resistance is improved. Will be improved.

The sulfonated polyphenylsilsesquioxane is, for example,

Reacting by administering trimethoxyphenylsilane to a solvent such as an aqueous tetrahydrofuran (THF) solution, and then separating a solution in which the polyphenylsilsesquioxane component is dissolved;

Drying the separated solution to obtain a polyphenylsilsesquioxane powder; and

Sulfonating the polyphenylsilsesquioxane powder

It may be prepared to include.

The step of sulfonating the polyphenylsilsesquioxane can be used without limitation general sulfonation reaction, it is also possible to dissolve the polyphenylsilsesquioxane powder in an organic solution, and then to administer sulfuric acid chloride.

The molar ratio of polyaniline and sulfonated polyphenylsilsesquioxane in the polyaniline doped with sulfonated polyphenylsilsesquioxane is not particularly limited, but is preferably 1: 0.1 to 2.0. More preferably, it is 1: 0.5-1.0. If the amount is less than 1: 0.1, the amount of the dopant may not be improved, and thus the electrical conductivity and the heat resistance may not be improved. If the ratio is greater than 1: 2.0, the ratio of polyaniline is relatively decreased, resulting in a decrease in the electrical conductivity.

The conductive polyaniline doped with the polyaniline sulfonated polyphenylsilsesquioxane may be prepared by dissolving polyaniline and sulfonated polyphenylsilsesquioxane in an organic solvent, stirring and drying. The organic solvent may be any organic solvent capable of dissolving both polyaniline and sulfonated polyphenylsilsesquioxane, but without limitation, meta-cresol, N-methylpyrrolidone, dimethyl sulfoxide (DMSO), and dimethylformamide. It is preferable to select (DMF), phenols, dichloroacetic acid, isoprolyl alcohol or tetrahydroquinone because of excellent solubility of polyaniline.

Hereinafter, the present invention will be described in more detail with reference to examples, but the following examples are merely to illustrate the present invention, but it should be understood that the present invention is not limited thereto.

Manufacturing example  : Sulfonated Of polyphenylsilsesquioxane (S-PPSQ)  synthesis

A 1 L round flask was charged with 24 g (1.33 mol) of deionized water and a base catalyst and stirred for about 10 minutes. 40 g (0.56 mol) of anhydrous tetrahydrofuran (THF) was administered and stirred for another 30 minutes. Thereafter, 79.32 g (0.4 mol) of trimethoxyphenylsilane was administered under a nitrogen atmosphere, and reacted by stirring at room temperature for 36 hours. After 36 hours, the solution was separated into a colorless liquid and a white liquid, which were able to separate white viscous product by deconversion.

The white viscous product was dispersed in 150 ml of methylene chloride (MC) and 200 ml of deionized water was extracted over two hours. Thereafter, the MC solution was dried with MgSO ₄ for about 24 hours. The MC solution was filtered through anhydrous MgSO ₄ using a filter, and then vaporized at a temperature of 40 ° C. to obtain 49.1 g (yield 95%) of pure polyphenylsilsesquioxane (PPSQ) powder.

The polyphenylsilsesquioxane powder (Mw: about 10,000 g / mol, Mn 4,700 g / mol, PDI 2.13) was dried in a vacuum oven at 50 ° C. for 24 hours. The PPSQ and MC solutions were stirred until a single phase solution in a reactor equipped with a reflux condenser. Sulfuric acid chloride was administered slowly to sulfonate the single phase PPSQ / MC solution (molar ratio of PPSQ to sulfuric acid chloride 1: 1.2). PPSQ / MC / sulfonic acid chloride of the same phase was mixed by stirring at 60 ° C for 12 hours. After the reaction was completed, the mixed solution was carefully administered to isopropyl alcohol (IPA). The precipitate was filtered off, washed several times with a neutral solution, and dried at 40 ° C. for 24 hours to obtain S-PPSQ.

A spectroscopic graph of sulfonated polyphenylsilsesquioxane and polyphenylsilsesquioxane is shown in FIG. 1. Although almost the same in all parts, there are some differences from 3000 to 3300, and this part represents sulfone groups, and it was confirmed that sulfonation was smoothly performed. The sulfonation degree was measured using the titration method, and the sulfonation degree was about 73%.

Example  One

Polyaniline (PANI) was prepared according to Korean Patent 10-0648894, and 0.2627 g of polyaniline and 0.1398 g of S-PPSQ (molar ratio 1: 0.5) thus prepared were ground for about 30 minutes using a mortar and pestle. PANI / S-PPSQ powder was added in small portions several times in a 70 ml glass bottle containing 30 ml of m-cresol. Stir at room temperature for about 2 weeks.

The PANI / S-PPSQ solution was applied to a 2.5 x 2.5 cm slide glass using a disposable pipette. Covered with a funnel and dried for about 3 days in a 50 ℃ heater.

Example  2

A film was prepared in the same manner as in Example 1 except that the molar ratio of PANI and S-PPSQ was 1: 0.75.

Example  3

A film was prepared in the same manner as in Example 1, except that the molar ratio of PANI and S-PPSQ was 1: 1.

Comparative example  One

0.2624 g of polyaniline (PANI) and 0.3376 g of camphorsulfonic acid (CSA) (molar ratio 1: 0.5) were ground for 30 minutes using a mortar and pestle. PANI / CSA powder was added in small portions several times in a 70 ml glass bottle containing 30 ml of meta-cresol. Stir at room temperature for about 2 weeks.

The PANI / CSA solution was applied to a 2.5 × 2.5 cm slide glass using a disposable pipette. Covered with a funnel and dried for about 3 days in a 50 ℃ heater.

Experimental Example  1: electrical conductivity measurement

The electrical conductivity of the prepared film was measured using a four-terminal method to remove contact resistance between the gold wire electrode and the sample.

The film and gold wire were contacted using a carbon paste, and the thickness of the film was measured using a "micrometer" manufactured by Mitutoyo.

Current and voltage were measured using KEITHLEY's "Source-Measure Units Model 237". The measurement method is to measure the voltage difference (V) caused by applying a constant source current (I, DC current) to the two outer terminals at the two inner terminals. During measurement, the source current is based on the area where the voltage increases linearly in the current of 100 ㎂, 1 ㎃, and 10 전압, and the voltage difference measured with a source current of 200 ㎂, 2 ㎃, 20 ㎃ Compared with.

Electrical conductivity was calculated using Equation 1 below.

σ: electrical conductivity (S cm ^-1 , reciprocal of Ωcm)

I: constant source current (DC current) applied to the sample (A)

V: Voltage measured when applying constant source current (V)

t: film thickness (cm)

l: length between electrodes

d: length of the film in contact with the terminal (width of the film)

The electrical conductivity of the films prepared in Examples 1 to 3 was measured at 25 ° C., and is shown in FIG. 2. As can be seen in FIG. 2, the highest electrical conductivity can be obtained when the molar ratio is 1: 0.75 (Example 2).

Experimental Example  2: heat resistance test

The films prepared in Example 1 and Comparative Example 1 were placed on a heat transfer plate, and TGA was measured under a nitrogen atmosphere, and then shown in FIG. 3.

As can be seen in FIG. 3, in contrast to Example 1, which shows a steadily stable characteristic up to 400 ° C., it can be seen that in Comparative Example 1, a sudden weight loss occurs in a 250 ° C. subgroup. Thus, it can be seen that the heat resistance of Example 1 is superior to Comparative Example 1.

Moreover, after adjusting the temperature of the heat exchanger plate to 120 degreeC and 150 degreeC, electrical conductivity was measured by the method of Experimental example 1. In the case of Example 1, as shown in FIG. 4, the electrical conductivity was maintained at 120 ° C. regardless of the time, but in the case of Comparative Example 1, it was found that the electrical conductivity fell close to half. In addition, as shown in Figure 5, Example 1 was maintained at 60% of the electrical conductivity when adjusted to 150 ℃, Comparative Example 1 was found to fall to 10%. Also in the holding surface of electrical conductivity, it turned out that the heat resistance of Example 1 is excellent.

The film prepared in Example 3 was changed in temperature at 20 to 180 ° C., and the resistance value, resistance / thickness, (resistance at 20 ° C.) / (Resistance at current temperature) were measured and shown in FIGS. 6 to 8. As shown in FIGS. 6 to 8, the film prepared in Example 3 exhibits a characteristic of low resistance as the temperature increases. As such, although the rate of change of the resistance is not high, the characteristic that the resistance decreases as the temperature rises, that is, the conductivity increases, is very important. In general, it is necessary to reduce the resistance change with temperature in an embedded capacitor or resistor so that a constant current flows. However, most conductive plastics in which metal particles are injected into plastics need to be reduced because the resistance increases as the temperature increases. In this case, if the material of the present invention is used to offset the increase in resistance according to temperature, the composite material may be appropriately configured to manufacture an ideal embedded capacitor or resistor with little change.

Claims (7)

Conductive polyaniline doped with polyaniline sulfonated PolyPenylSilsesQuioxane (S-PPSQ).
The conductive polyaniline according to claim 1, wherein the sulfonated polyphenylsilsesquioxane is sulfonated polyphenylsilsesquioxane represented by the following formula (2).
(2)

In Formula 2 n is an integer of 5 to 20000.
The conductive polyaniline according to claim 2, wherein the sulfonation degree of the sulfonated polyphenylsilsesquioxane is 10 to 100%.
The conductive polyaniline of claim 1, wherein the sulfonated polyphenylsilsesquioxane is represented by the following Chemical Formula 3.
(3)

In Formula 3, n is an integer of 5 to 20000.
The conductive polyaniline according to claim 1, wherein the molar ratio of the polyaniline to the sulfonated polyphenylsilsesquioxane is 1: 0.1 to 2.0.
A method for producing a conductive polyaniline comprising dissolving polyaniline and sulfonated polyphenylsilsesquioxane in an organic solvent, stirring and drying.
The method of claim 6, wherein the organic solvent is meta-cresol, N-methylpyrrolidone, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), phenols, dichloroacetic acid, isoproyl alcohol or tetrahydroquinone Method for producing a conductive polyaniline characterized in that.

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