KR101198743B1 - Polypropylene/carbon nanotube composites, nanocomposites that the polypropylene/carbon nanotube composites are homogeneously dispersed in polypropylene matrix, and preparation method thereof - Google Patents

Abstract

The present invention relates to a polypropylene / carbon nanotube composite, a nanocomposite in which the polypropylene / carbon nanotube composite is uniformly dispersed in a polypropylene matrix, and a manufacturing method thereof. When producing the polypropylene / carbon nanotube composite according to the present invention, an amorphous polypropylene layer having a thickness of 10-15 nm is formed on the wall surface of the carbon nanotubes, thereby improving compatibility with the polypropylene matrix. In the case of the nanocomposite in which the polypropylene / carbon nanotube composite of the present invention is included in a polypropylene matrix of 1% by weight or more, thermal stability and thermal conductivity are significantly improved. The excellent miscibility of polypropylene and polypropylene / carbon nanotube composites plays a very important role in the formation of uniform composites, leading to high thermal stability and thermal conductivity.

Description

POLYPROPYLENE / CARBON NANOTUBE COMPOSITES, NANOCOMPOSITES THAT THE POLYPROPYLENE / CARBON NANOTUBE COMPOSITES ARE HOMOGENEOUSLY DISPERSED IN POLYPROPYLENE MATRIX, AND PREPARATION METHOD THEREOF}

The present invention relates to a polypropylene / carbon nanotube composite, a nanocomposite in which a polypropylene / carbon nanotube composite is uniformly dispersed in a polypropylene matrix, and a method of manufacturing the same.

Carbon nanotubes (CNTs) are hexagonal honeycomb graphite surfaces in which one carbon atom is bonded to three other carbon atoms, which are rounded to a nano-sized diameter, and are large molecules with unique physical properties depending on their size and shape. . Depending on the shape of the roll, it may be divided into single walled nanotubes (SWNTs), multi-walled nanotubes (MWNTs), and rope nanotubes.

These carbon nanotubes have excellent physical and electrical properties that can be utilized in nanotechnology and electronic nanodevices. In recent years, as the interest in heterogeneous composites having excellent mechanical strength, special composite properties, and excellent processability by combining the physical properties of the two components has been actively studied for the composite of polymer / carbon nanotubes. However, despite the excellent properties of the polymer / carbon nanotube composites, the development of the polymer / carbon nanotube composites is limited due to the low dispersibility of the carbon nanotubes and the self-cohesion caused by van der Waals forces. It remains a challenge to overcome. Therefore, in preparing a composite of polymer / carbon nanotubes, it is a major concern to have a uniform dispersibility and to have interfacial stability without aggregation or desorption of carbon nanotubes in a polymer matrix.

Many researchers have focused on the functionalization of carbon nanotubes with a variety of organic, inorganic and organometallic structures using non-covalent and covalent interactions. Non-covalent interactions such as π-π interactions, π-anion interactions, and ionic bonds between the carbon nanotubes and the polymer enable the polymer to bind to the walls of the carbon nanotubes.

There are various methods of introducing polymers to the walls of carbon nanotubes, but chemical methods such as "grafting to" and "grafting from" are widely used. The "grafting to" method is a method of introducing a polymer through a chemical reaction between a pre-synthesized polymer and carbon nanotubes, for example, an esterification reaction or an amidation reaction. In addition, the "grafting from" method is a method of introducing a polymer by introducing an initiator functional group capable of polymerizing monomers on the walls of the carbon nanotubes and then polymerizing the carbon nanotubes by in-situ. As an example, atom transfer radical polymerization (ATRP) is mentioned.

Conventional composites in which pure carbon nanotubes are dispersed in a polypropylene matrix are prepared by melt mixing using carbon nanotubes at a concentration of 5 to 20% with respect to polypropylene. This approach produces polypropylene / carbon nanotube composites without modifying the walls of the carbon nanotubes. Such composites have a high concentration of carbon nanotubes and have a disadvantageous effect on improving the thermal and electrical properties of the composite due to the low compatibility between the carbon nanotubes and polypropylene.

The inventors of the present invention intensively studied the polypropylene / carbon nanotube composites and a method for producing the same, the polypropylene / carbon nanotube composites in which a compound layer containing a polypropylene end group is introduced into the wall of the carbon nanotubes and the polypropylene matrix It has been found that it can be uniformly dispersed in the polypropylene matrix by improving the compatibility of the polymer.

It is an object of the present invention to provide a polypropylene / carbon nanotube composite and a method for producing the same that can improve compatibility with a polypropylene matrix.

Another object of the present invention is to provide a nanocomposite in which a polypropylene / carbon nanotube composite is uniformly dispersed in a polypropylene matrix and a method of manufacturing the same.

In order to achieve the above object, the present invention provides a polypropylene / carbon nanotube composite comprising a carbon nanotube and a compound layer containing a polypropylene end group introduced to the wall surface of the carbon nanotube.

The present invention comprises the steps of sonicating a mixture of carbon nanotubes and an organic solvent grafted with a compound having a bromine end group, and adding polypropylene and a catalyst grafted with a compound having a hydroxyl group to the mixture. It provides a method for producing a polypropylene / carbon nanotube composite comprising.

The present invention provides a nanocomposite in which a polypropylene / carbon nanotube composite is uniformly dispersed in a polypropylene matrix.

The polypropylene / carbon nanotube composite of the present invention may be uniformly dispersed in the polypropylene matrix by improving compatibility with the polypropylene matrix. The nanocomposite in which the polypropylene / carbon nanotube composite of the present invention is uniformly dispersed in a polypropylene matrix has thermal stability and thermal conductivity compared to nanocomposites (prior art) and pure polypropylene in which pure carbon nanotubes are dispersed in a polypropylene matrix. Is significantly improved. Nanocomposite according to the present invention can be used for a variety of applications, such as packaging materials, antistatic film, pipes, insulation, car bumper, thermal conductive film.

FIG. 1 briefly illustrates a method for synthesizing a polypropylene / multi-walled carbon nanotube composite prepared according to Example 1. FIG.
2 is (a) commercially available multi-walled carbon nanotubes measured using KBr, (b) multi-walled carbon nanotubes functionalized with hydroxyl groups prepared according to Example 1, (c) Example 1 Fourier transform infrared (FT-IR) spectra of multi-walled carbon nanotubes grafted with 2-bromo-2-methylpropionate groups prepared according to the present invention.
FIG. 3 shows FT- of grafted polypropylene (PP-OH) grafted with (a) commercially available PP-MAH, (b) hydroxyl group prepared according to Example 1, measured using KBr. IR spectrum.
Figure 4 is a multi-walled carbon nanotube grafted with a compound having a bromine end group prepared according to Example 1 measured using KBr, (b) having a hydroxyl group prepared according to Example 1 FT-IR spectra of polypropylene grafted with compounds and (c) polypropylene / multi-walled carbon nanotube composites prepared according to Example 1.
5 is a transmission electron microscope (TEM) photograph of a polypropylene / multi-walled carbon nanotube composite prepared according to Example 1 on a carbon coated copper grid.
FIG. 6 shows (a) pure polypropylene, (b) polypropylene / pure multi-walled carbon nanotube composites (prior art) and (c) nanocomposites prepared according to Example 2 at 10 ° C. per minute under a nitrogen atmosphere. It is a graph which shows the result measured by the thermogravimetric ananlysis (TGA) measured by the heating rate.
7 is a disk prepared for testing the dispersion characteristics of (a) pure polypropylene, (b) polypropylene / pure multi-walled carbon nanotube composites (prior art) and (c) nanocomposites prepared according to Example 2. And film photography.
FIG. 8 is a field emission scanning electron microscope (FE-SEM) image of the cryogenic crushed surface of a polypropylene / pure multi-walled carbon nanotube composite (prior art) on a silicon wafer.
9 is an FE-SEM image of the cryogenic grinding surface of a nanocomposite (invention) prepared according to Example 2 on a silicon wafer.
10 is a FE-SEM photograph of commercially available multi-walled carbon nanotubes (a, b) and polypropylene / multi-walled carbon nanotube composites (c, d) prepared according to Example 1. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Polypropylene / Carbon Nanotube Composites

The present invention provides a polypropylene-carbon nanotube composite including a carbon nanotube and a compound layer containing a polypropylene end group introduced into a wall of the carbon nanotube.

Any compound layer having polypropylene end groups may be introduced into the wall of the carbon nanotubes of the present invention. Specifically, it is preferable that the compound layer containing the polypropylene end group represented by the following formula (1) is introduced into the wall surface of the carbon nanotubes.

[Formula 1]

Wherein PP is polypropylene

The compound layer containing the polypropylene end group of the present invention is an amorphous layer and is formed uniformly on the carbon nanotube wall surface.

The carbon nanotubes of the present invention may be single-walled nanotubes, multi-walled nanotubes, or the like, with multi-walled nanotubes being particularly preferred.

Method for producing a polypropylene / carbon nanotube composite of the present invention,

Sonicating a mixture of carbon nanotubes and an organic solvent grafted with a compound having a bromine end group, and adding polypropylene and a catalyst grafted with a compound having a hydroxyl group to the mixture, followed by stirring do.

Since the method for producing a polypropylene / carbon nanotube composite of the present invention is characterized in that the bromine group of the carbon nanotubes and the hydroxyl group of the polypropylene are substituted and reacted, the compound having a bromine end group grafted to the carbon nanotubes has a terminal Any compound having a bromine group, such as, but not limited to, 2-bromobutyryl bromide, 2-bromopropanoyl bromide, and a compound having a hydroxyl group grafted to polypropylene It may be any compound having a hydroxyl group, such as, but not limited to, N- (2-hydroxyethyl) ethylenediamine.

The organic solvent and the catalyst used in the method for producing the nanocomposite of the present invention can be appropriately selected by those skilled in the art. Examples of organic solvents include, but are not limited to, o-xylene, and examples of catalysts include triethylamine and imidazole.

A carbon nanotube grafted with a compound having a bromine end group to be used in the method of the present invention, represented by the following Chemical Formula 2 prepared by bromination of a hydroxyl group-functionalized carbon nanotube and 2-bromobutyryl bromide Can be used.

[Formula 2]

Wherein CNT is carbon nanotube

The bromination reaction is usually carried out under mild conditions to avoid side reactions. However, the bromination reaction of the present invention including carbon nanotubes should be carried out for a long time at high temperature because of low solubility and low hydroxyl group concentration. The bromination reaction of the present invention is preferably carried out for 12 to 48 hours at 90 ~ 120 ℃, particularly preferably for 24 hours at 105 ℃.

As a polypropylene grafted with a compound having a hydroxyl group used in the method of the present invention, a compound of formula 3 prepared by reacting polypropylene grafted with maleic anhydride and ethanolamine may be used. This reaction can be carried out at 110 ~ 130 ℃ using o-xylene as a solvent.

(3)

Wherein PP is polypropylene

Nanocomposite in which the polypropylene / carbon nanotube composite of the present invention is uniformly dispersed in a polypropylene matrix

In general, pure carbon nanotubes are easy to aggregate with each other due to large surface area and large van der Waals interactions, and the aggregated carbon nanotubes cause incompatibility with organic polymers. In order to overcome this disadvantage, the present invention provides a polypropylene / carbon nanotube composite including a carbon nanotube and a compound layer containing a polypropylene end group introduced to the wall of the carbon nanotubes, in which the polypropylene matrix is uniformly dispersed. Provided are nanocomposites.

The carbon nanotubes of the nanocomposite of the present invention may be single wall nanotubes, multiwall nanotubes, or the like, and multiwall nanotubes are particularly preferred.

As the polypropylene / carbon nanotube composite used to prepare the nanocomposite of the present invention, a polypropylene / carbon nanotube composite prepared according to the method of the present invention may be used, and the preparation method thereof is described above. The polypropylene / carbon nanotube composite of the present invention is characterized in that a compound layer containing polypropylene end groups is introduced into the wall of the carbon nanotubes, and the polypropylene end groups interact with the polypropylene to The propylene / carbon nanotube composite can be uniformly dispersed in the polypropylene matrix.

The nanocomposites of the present invention exhibit significantly improved dispersibility compared to polypropylene / pure carbon nanotube composites and pure polypropylene.

The content of the polypropylene / carbon nanotube composite in the nanocomposite of the present invention may be 1% by weight or more. In particular, due to the strong interaction between the polypropylene and the polypropylene matrix of the polypropylene / carbon nanotube composite of the present invention, the thermal stability even when the content of the polypropylene / carbon nanotube composite in the nanocomposite of the present invention is 1% by weight. And thermal conductivity can be significantly improved.

The nanocomposite of the present invention can be produced by a solution mixing method. Specifically, the method for producing a nanocomposite of the present invention includes the step of sonicating the mixture of the polypropylene / carbon nanotube composite and the organic solvent of the present invention, and adding and stirring the polypropylene to the mixture.

The organic solvent used in the method for producing a nanocomposite of the present invention can be appropriately selected by those skilled in the art. Any organic solvent having a boiling point of 140 ° C. or higher can be used, and examples of such organic solvents include, but are not limited to, o-xylene.

In the method for producing a nanocomposite of the present invention, the step of adding and stirring polypropylene should be performed at a high temperature. Temperatures in the range from 140 to 160 ° C. are preferred, and temperatures of about 150 ° C. are particularly preferred. At temperatures lower than the temperature range, the polypropylene does not dissolve uniformly in the solvent. Therefore, the polypropylene / carbon nanotube composite may not be uniformly dispersed in the polypropylene matrix, thereby deteriorating mechanical and thermal properties.

Hereinafter, preferred embodiments for the purpose of helping the present invention, but the following examples are merely to illustrate the invention, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the invention. And modifications fall within the scope of the appended claims.

Example

The access routes of the materials used in the examples below are as follows:

Multi-walled carbon nanotubes: Iljin Nanotech, 10-20 nm in diameter, 10-50 μm in length, greater than 90% by volume purity

Polycarbonate membrane: Whatman Internationl Ltd., pore size of 200 nm

Polypropylene-graft-maleic anhydride (PP-MAH): Aldrich (male anhydride: 8-10 wt%, number average molecular weight (Mn): 3900, weight average molecular weight (Mw): 9100)

Bromoisobutyryl bromide: used without additional purification after purchase of Aldrich.

Triethylamine: Used after distilling on calcium hydride after purchasing Aldrich.

Hydrogen peroxide (30%), nitric acid (60%) and all solvents: Aldrich.

Example  1: polypropylene / Multiwall  Preparation of Carbon Nanotube Composite

(One) With hydroxyl  Functionalized Multiwall  Carbon nanotube ( MWCNT - OH Manufacturing

Under vigorous stirring, 6.0 g of amorphous multiwalled carbon nanotubes, 200 mL of 30% hydrogen peroxide were added to a 500 mL flask equipped with a cooler. The flask was immersed in an ultrasonic bath (40 kHz) for 2 hours and then the mixture was stirred at 90 ° C. for 24 hours. After cooling to room temperature, the reaction mixture was diluted with 800 mL of deionized water and vacuum filtered through a 0.2 μm polycarbonate filter paper. The dispersion, filtration and washing steps were repeated until the filtrate had a pH of 7. The filtered solid was washed 5 times with 100 mL of acetone and THF to remove water and dried for 24 hours under vacuum at 60 ° C. to obtain multi-walled carbon nanotubes functionalized with hydroxyl groups. The functionalization of the multi-walled carbon nanotubes with the hydroxyl group can be confirmed by the CO stretching peak of the hydroxyl group at 1260-1000 cm ⁻¹ in FIG.

(2) bromine Terminal group  With compound Grafted Multiwall  Carbon nanotube ( MWCNT - Br Manufacturing

3.0 g of MWCNT-OH and 200 mL of toluene obtained in (1) were added to a 300 mL flask and sonicated for 2 hours. Thereafter, 2-bromoisobutyryl bromide (6.7 mL, 54.4 mmol) and triethylamine (8.1 mL, 54.4 mmol) were charged. After stirring for 2 hours at room temperature to form a black suspension, the flask was connected to a cooler and the mixture was stirred for 24 hours at 105 ° C. under a nitrogen atmosphere. The reaction mixture was collected by filtration, washed with methanol and dried in vacuo at 80 ° C. for 12 h. As a result, a multi-walled carbon nanotube grafted with 2-bromo-2-methylpropionate was obtained. The multi-walled carbon nanotubes were grafted with 2-bromo-2-methylpropionate, which showed the C = O peak at 1710 cm ⁻¹ and 1300-1160 cm in the FT-IR spectrum shown in FIG. 2 (c). ^This can be confirmed by the CO peak at ^-1 .

(3) Hydroxyl group  With compound Grafted  Polypropylene ( PP - OH Manufacturing

700 mL o-xylene, PP-MAH (75 g, 2.5 mmol-MAH) was placed in a 1 L glass reactor equipped with a mechanical stirrer and reacted at 120 ° C. for 3 hours under a nitrogen atmosphere. Ethanolamine (200 mL, 3.3 mmol) was then added and the mixture was kept at 120 ° C. for 6 hours with stirring. The obtained reaction mixture was poured into 2 L of acetone. The precipitate was collected by filtration, washed with acetone and dried in vacuo at 80 ° C. for 10 hours to give 75.1 g of polypropylene grafted with a compound having hydroxyl groups of white powder. The polypropylene was grafted with a compound having hydroxyl groups from the new C═O peak at about 1700 cm ⁻¹ in the FT-IR spectrum shown in FIG. 3 (b).

(4) Preparation of Polypropylene / Multi-walled Carbon Nanotube Composites

0.5 g of MWCNT-Br obtained in (2) was added to a 250 mL flask with 150 mL of toluene and sonicated for 3 hours. Then, PP-OH (0.5 g) and triethylamine (8.0 mL, 54.4 mmol) obtained in (3) were added thereto. Stirred at room temperature for 2 hours to form a black suspension, then stirred at 120 ° C. for 72 hours under nitrogen atmosphere. The mixture was collected by filtration, washed with hot toluene and then dried under vacuum overnight to prepare a polypropylene / multi-walled carbon nanotube composite.

Example 2 Preparation of Nanocomposites with Polypropylene / Carbon Nanotube Composites Uniformly Dispersed in a Polypropylene Matrix

0.1 g of the polypropylene / carbon nanotube composite prepared in Example 1 and 200 mL of o-xylene were added to a 300 mL flask and sonicated at room temperature for 3 hours to obtain a homogeneous solution. 10 g of polypropylene was added to the solution and stirred at 150 ° C. for 2 hours. The stirred mixture was poured into 1 L of methanol to form a precipitate. The formed precipitate was filtered using a 200 nm porous membrane and dried under vacuum to prepare a nanocomposite in which the polypropylene / carbon nanotube complex was dispersed in the polypropylene matrix.

On the other hand, the composite of the prior art used in Experimental Examples 3 to 5 is a nanocomposite prepared by dispersing the pure carbon nanotubes of which the surface is not modified in the polypropylene matrix in the same manner as in Example 2. Hereinafter referred to as "polypropylene / pure carbon nanotube composite (prior art)".

Experimental Example 1 FT-IR Spectrum Measurement

Multi-walled carbon nanotubes (MWCNT-Br) grafted with a compound having bromine end groups prepared in Example 1, polypropylene (PP-OH) and polypropylene / multi-walls grafted with a compound having hydroxyl groups The FT-IR spectrum of the carbon nanotube composite was measured and shown in FIG. 4. In spectrum (a) of MWCNT-Br, weak absorption peaks representing C = O and C-0 stretching vibrations of ester groups of 2-bromo-2-methylpropionate on the wall of multi-walled carbon nanotubes are 1710 and 1300. -1160 cm ^-1 , the spectrum of PP-OH (b) shows sp ³ CH stretching peak of polypropylene skeleton at 2900 cm ^-1 and C = 0 stretching vibration peak of succinimide group at 1700 cm ^-1 Was observed. Spectrum (c) of the polypropylene / multi-walled carbon nanotube composite showed a new absorption peak of the polypropylene backbone at 2950-2800 cm ⁻¹ .

Experimental Example 2 Characterization Experiment of Polypropylene / Multi-walled Carbon Nanotube Composite Structure Prepared in Example 1

A transmission electron microscope (TEM) photograph for characterizing the structure of individual polypropylene / multi-walled carbon nanotube composites is shown in FIG. 5. For TEM observation, a solution of the redispersed polypropylene / multi-walled carbon nanotube composite prepared in Example 1 in toluene was dropped on a carbon coated copper grid and vacuum dried. As a result of TEM observation, it can be seen that an amorphous polypropylene layer is formed on the multi-walled carbon nanotubes with a thickness of 10-15 nm. In addition, it can be seen that the polypropylene is uniformly deposited on the wall surface of the multi-walled carbon nanotubes.

< Experimental Example  3> Thermogravimetric

In order to compare the thermal stability of polypropylene, polypropylene / pure multi-walled carbon nanotube composites (prior art) and nanocomposites of the present invention, TGA was measured in an inert atmosphere at a heating rate of 10 ° C. per minute and the results are shown in FIG. 6. Indicated. Polypropylene exhibited an initial decomposition temperature at 319 ° C. and completely degraded at a temperature of about 427 ° C. However, after the addition of pure multi-walled carbon nanotubes, the decomposition temperature of the composite shifted to a temperature higher than 319 ° C., the decomposition temperature of polypropylene. In addition, the composites of the prior art and the nanocomposites of the present invention did not completely decompose even at temperatures in the range of 450 to 600 ° C. due to the excellent thermal stability of multi-walled carbon nanotubes. In particular, the nanocomposites of the present invention were decomposed at 355 ° C., which is higher than the decomposition temperature of 334 ° C. of the prior art composites. These results demonstrate that the thermal stability of the nanocomposites of the present invention is improved.

< Experimental Example  4> Comparative Experiment of Dispersibility of Nanocomposites of the Present Invention

In order to compare the dispersibility of pure polypropylene (a), polypropylene / pure multi-walled carbon nanotube composite (b) and nanocomposite (c) prepared in Example 2, each disk and film were hot pressed (Pressure: 5 MPa, temperature: 180 ° C.), and the results are shown in FIG. 7. The concentration of pure multi-walled carbon nanotubes in the polypropylene matrix and the concentration of the polypropylene / multi-walled carbon nanotube composites prepared in Example 1 were 1% by weight. As illustrated in Fig. 7 (a), both the film and disk of pure polypropylene were transparent. However, after adding the multi-walled carbon nanotubes in the polypropylene matrix, the composites all lost transparency. As can be seen in Figure 7 (b), in the case of polypropylene / pure multi-walled carbon nanotube composites, a large number of aggregated mass of multi-walled carbon nanotubes were observed. However, as can be seen in Figure 7 (c), in the case of the nanocomposite prepared in Example 2, the aggregated mass cannot be observed. This demonstrates that the polypropylene / multi-walled carbon nanotube composite prepared in Example 1 is uniformly dispersed in the polypropylene matrix, which is based on good miscibility with polypropylene.

On the other hand, the improved dispersibility of the polypropylene / multi-walled carbon nanotube composite prepared in Example 1 in the polypropylene matrix is shown in FIGS. 8 (polypropylene / pure multi-walled carbon nanotube composite-prior art) and 9 (invention). It can also be confirmed by the FE-SEM photograph.

< Experimental Example  5> Comparison of thermal diffusivity and thermal conductivity of nanocomposites of the present invention

To measure the thermal conductivity of the composite, the following method is followed. The thermal diffusivity was measured by the laser flash method. Laser heating pulses were irradiated on the entire surface of the sample. The thermal diffusivity was calculated using the increased temperature and time up to half the maximum temperature when the heat moved from front to back in the sample thickness direction.

Specific heat (C _p ) values of the composites with multi-walled carbon nanotubes were determined using differential scanning calorimetry (DSC) at 22 ° C. Temperature and heat flow scales were calibrated with indium at 0-65 ° C. under a nitrogen atmosphere. The following procedure was carried out on an empty pan, a sapphire and a pan containing the sample: annealing at 0 ° C. for 5 minutes, heating in the range of 0 to 65 ° C. at a heating rate of 10 ° C./min and annealing at 65 ° C. for 5 minutes.

Thermal conductivity was calculated from the thermal diffusivity using equation (1). Here, the specific heat and sample density should already be known.

k = αρC _{p ... …} (One)

(Wherein k = thermal conductivity (W / mK), α = thermal diffusivity (cm 2 / s), ρ = density (g / cm 3) and C _p = specific heat (J / gK))

The thermal diffusivity, density, specific heat and thermal conductivity of each sample were measured and shown in Table 1.

sample Thermal diffusivity (/ s) Density (g /) Heat capacity (J / g-K) Thermal Conductivity (W / m-K) Polypropylene 1.432 × 10 ^-3 0.831 1.925 0.229 Polypropylene / Pure Multiwalled Carbon Nanotube Composites
(Prior art)
2.58 × 10 ^-3
0.941
1.907
0.464 Nanocomposite prepared in Example 2 (invention)
5.27 × 10 ^-3
0.976
1.83
0.941

The nanocomposite prepared in Example 2 from Table 1 can be confirmed that the thermal diffusivity and thermal conductivity significantly improved. From these results, it can be seen that in the nanocomposite prepared in Example 2, the agglomeration of the polypropylene / multi-walled carbon nanotube composite prepared in Example 2 did not occur and was uniformly dispersed in the polypropylene matrix.

Claims (16)

Carbon nanotubes; And
As a polypropylene / carbon nanotube composite comprising a compound layer containing a polypropylene end group introduced to the wall of the carbon nanotubes,
Compound layer containing the polypropylene end group is a polypropylene / carbon nanotube composite, characterized in that represented by the following formula (1).
[Formula 1]

Wherein PP is polypropylene delete The method of claim 1,
The compound layer containing the polypropylene end group is a polypropylene / carbon nanotube composite, characterized in that formed in a thickness of 10 ~ 15 nm. The method of claim 1,
The carbon nanotube is a polypropylene / carbon nanotube composite, characterized in that the multi-walled carbon nanotubes. Sonicating a mixture of carbon nanotubes and an organic solvent grafted with a compound having bromine end groups;
Adding polypropylene and a catalyst grafted with a compound having a hydroxyl group to the mixture and then stirring
Method for producing a polypropylene / carbon nanotube composite comprising a. The method of claim 5,
Carbon nanotube grafted with a compound having a bromine end group,
Method for producing a polypropylene / carbon nanotube composite, characterized in that represented by the formula (2) prepared by bromination of the carbon nanotubes and 2-bromobutyryl bromide functionalized with a hydroxyl group.
(2)

Wherein CNT is carbon nanotube The method according to claim 6,
The bromination reaction is a method for producing a polypropylene / carbon nanotube composite, characterized in that carried out for 12 to 48 hours at 90 ~ 120 ℃. The method of claim 5,
Polypropylene grafted with a compound having a hydroxyl group,
Method for producing a polypropylene / carbon nanotube composite, characterized in that represented by the formula (3) prepared by reacting maleic anhydride grafted polypropylene and ethanolamine.
(3)

Where PP is polypropylene 9. The method according to any one of claims 5 to 8,
The carbon nanotubes are polypropylene / carbon nanotube composites, characterized in that the multi-walled carbon nanotubes. As a nanocomposite in which a polypropylene / carbon nanotube composite including a carbon nanotube and a compound layer containing a polypropylene end group introduced into a wall of the carbon nanotube is uniformly dispersed in a polypropylene matrix,
The compound layer containing the polypropylene end group is represented by the formula (1), characterized in that the polypropylene / carbon nanotube composite is uniformly dispersed in the polypropylene matrix nanocomposite.
[Formula 1]

Wherein PP is polypropylene The method of claim 10,
The polypropylene / carbon nanotube composite is characterized in that the content of more than 1% by weight, nanocomposite is a polypropylene / carbon nanotube composite uniformly dispersed in a polypropylene matrix. delete The method of claim 10,
The compound layer containing the polypropylene end group is a nanocomposite, wherein the polypropylene / carbon nanotube composite is uniformly dispersed in the polypropylene matrix, characterized in that formed in a thickness of 10 ~ 15 nm. Sonicating a mixture of an organic solvent and a polypropylene / carbon nanotube composite including a carbon nanotube and a compound layer containing a polypropylene end group introduced into the wall of the carbon nanotube; And
Adding and stirring polypropylene to the mixture;
The compound layer containing the polypropylene end group is represented by the following formula (1), polypropylene / carbon nanotube composite is a method for producing a nanocomposite uniformly dispersed in a polypropylene matrix.
[Formula 1]

Wherein PP is polypropylene 15. The method of claim 14,
The polypropylene / carbon nanotube composite is characterized in that the content of more than 1% by weight, polypropylene / carbon nanotube composite is a method for producing a nanocomposite uniformly dispersed in a polypropylene matrix. delete

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