KR101661598B1 - Polymer-Carbon compound composite material and method for preparing thereof - Google Patents

Abstract

The polymer-carbon composite material of the present invention can improve the solubility and dispersibility of the carbon compound by modifying and functionalizing the surface of the carbon compound such as graphene, and various functions depending on the intended use depending on the kind of the functional group bonded to the surface Can be given. Further, by filling the functionalized carbon compound so as to be uniformly dispersed in the matrix containing the polymer resin, the conventional carbon compound is filled in the polymer matrix, and the carbon compound is not dispersed, thereby deteriorating the mechanical properties of the composite material And maximize mechanical strength and electrical conductivity.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer-carbon composite material and a method for manufacturing the same,

The present invention relates to a polymer-carbon composite material and a method for producing the same.

As the needs of the consumers who develop the industry and use the products are diversified, high performance and high performance of the products are demanded, and researches for diversifying the characteristics of the original materials have been actively made. In particular, in the field of composite materials research, various characteristics can be realized by controlling the characteristics of the filler and the interaction between the filler and the mattress of the composite material, and thus attention has been focused on as an effective alternative to solve the problem of high performance and high performance of the product.

Today, researches are being actively carried out to develop high-functional polymer composite materials using carbon-based fillers such as carbon nanotubes, carbon fibers, and graphene. Of these, graphene is one of the most popular fillers. Graphene is a two-dimensional single sheet consisting of carbon sp2 and has excellent surface area, mechanical strength, thermal stability and electrical properties compared to other types of fillers. Therefore, studies are underway to maximize the physical properties of the composite material prepared by filling the graphene into the polymer resin.

However, the homogeneous dispersion of the filler is a very important factor to improve the physical properties of the composite material. On the contrary, graphene is a plate structure of pure carbon, which has a strong Van der Waals force and a π-π interaction, There is a problem in that it has a degree of difficulty.

Korean Patent Publication No. 10-2012-0104767

Nano Lett. 2012, 12, 1789-1793 Journal of Hazardous Materials 152 (2008) 601-606 Journal of Molecular Catalysis A: Chemical 370 (2013) 182-188 J. Mater. Chem. 2011, 21, 2971

The present invention provides a composite material containing a carbon compound and a polymer which solves the low solubility and dispersibility of a conventional carbon compound and further improves mechanical strength and electrical conductivity, and a method for producing the same.

In embodiments of the present invention,

A compound having the following formula (1) is covalently bonded to the surface carbon of at least one carbon compound selected from the group consisting of Graphene, Carbon nanotube, Carbon fiber and Clay, Carbon compounds; And polyimide, polyacrylonitrile, polyamide, polybenzoxazole, polybenzimidazole, polyvinyl alcohol, polyethylene terephthalate (PET), polystyrene, and polymethylacrylate which are filled with the functionalized carbon compound A polymer-carbon composite material comprising a matrix comprising at least one polymer resin selected from the group consisting of:

 [Chemical Formula 1]

(In the above formula (1), R _{1 ,} R _{2 ,} R ₃ , R ₄ And R ₅ is one selected from the group consisting of -O-, -COO-, -S-, -Se-, -NH- and -H, and R _{6 ,} R _{7 ,} R ₈ , R ₉ And R ₁₀ is a group consisting of hydrogen, chlorine, azide, epoxide, cycloepoxide, acrylate, methacrylate, and alkyne groups. And n is an integer selected from 1 to 20. The term " functional group "

In another embodiment of the present invention, there is provided a method for producing the polymer-carbon composite material, comprising the steps of: preparing a surface-modified carbon compound by covalently bonding a surface carbon of a carbon compound to a compound having the following formula 2;

R _{11 ,} R _{12 ,} R ₁₃ , R ₁₄ and R ₁₅ in the formula (2) covalently bonded to the surface- (S) selected from the group consisting of chlorine, azide, epoxide, cycloepoxide, acrylate, methacrylate, and alkyne groups. Covalently bonding the functional group to at least one functional group to prepare a functionalized carbon compound; And

Preparation of a polymer-carbon composite material in which a polymer precursor, a polymer resin, or a mixture thereof is put into a solution in which the functionalized carbon compound is dispersed and polymerized to fill the functionalized carbon compound into the polymer precursor, the polymer resin or a mixture thereof Comprising:

Wherein the polymer precursor is at least one selected from the group consisting of anhydride diamine, acrylonitrile, diamine, dihydroxy, vinyl alcohol, styrene, and meta methyl acrylate, and the polymer resin is at least one selected from the group consisting of polyimide, A method for producing a polymer-carbon composite material having at least one selected from the group consisting of nitrile, polyamide, polybenzoxazole, polybenzimidazole, polyvinyl alcohol, polyethylene terephthalate (PET), polystyrene and polymethylacrylate,

(2)

(Wherein R _{11 ,} R _{12 ,} R ₁₃ , R ₁₄ And R ₁₅ is -OH, -COOH, -SH, -SeH, -NH ₂ And -H. ≪ / RTI >

The composite material according to the embodiments of the present invention can improve the solubility and dispersibility of the carbon compound by modifying and functionalizing the surface of the carbon compound such as graphene, and at the same time, various kinds of functional groups Function can be given.

In addition, the composite material according to the embodiments of the present invention can control the functional groups that bind the functionalized carbon compound to the surface of the graphene depending on the properties of the polymer to be packed, and fill the functionalized carbon compound to be uniformly dispersed in the matrix containing the polymer Therefore, when the conventional simple carbon compound is filled in the polymer matrix, the carbon compound is not dispersed so that the mechanical property of the composite material is not significantly deteriorated, and the functionalized carbon compound forms a strong bond with the polymer Thereby maximizing mechanical strength and electrical conductivity.

1A to 1C are schematic diagrams showing the results of measurement of an alkylated-diaminobenzoic acid (a-DBA) prepared in Example 1 according to an embodiment of the present invention by (a) FT-IR, (b ) H ¹ -NMR, and (c) C ¹³ -NMR, respectively.
FIG. 2 is a graph showing the results of a process for preparing a polyamic acid according to Example 1 of the present invention and adding it to a solution containing graphene N ₃ -Ph-TGO to react with polyimide composite material filled with functionalized graphene And a process for producing the same.
3A, 3B and 3C show FT-IR (FIGS. 3A, 3B), Raman (FIG. 3B) and XPS (FIG. 3C) Fig.
Figure 4 shows the dispersions of functionalized graphene (N ₃ -TGO) and non-functionalized graphene (TGO) in DMF (N, N-dimethylmethanamide) solvent according to one embodiment of the present invention Graph.
FIG. 5 is a graph showing the tensile strength and tensile modulus of a composite material according to the weight of functionalized graphene, which is a polymer in a polymer-carbon composite material prepared according to an embodiment of the present invention, Respectively.

Hereinafter, embodiments of the present invention will be described in detail.

Embodiments of the present invention include a carbon compound in which at least one of aromatic and aliphatic compounds substituted with various functional groups is covalently bonded to the surface of a carbon compound and at least one other functional group is bonded to at least one of the substituted aromatic and aliphatic compounds, , And a matrix comprising a polymer material filled with the functionalized carbon compound. At this time, various functional groups of the aromatic or aliphatic compound are bonded to the surface of the carbon compound to modify the surface of the carbon compound, and various other functional groups are bonded thereto, so that the carbon compound has various functions depending on the type of the functional group to be bonded Functional.

Embodiments of the present invention are directed to a method of forming a carbon nanotube having a surface carbon of a carbon compound comprising a hydroxyl group, a carboxyl group, a thiol group, a selenol group and an amino group Wherein at least one of the aromatic and aliphatic compounds substituted with at least one functional group selected from the group is covalently bonded, and at least one of the substituted aromatic and aliphatic compounds is substituted with at least one of an azide, an epoxide, a carbon compound functionalized by bonding at least one functional group selected from the group consisting of cycloepoxide, acrylate, methacrylate and alkyne group, and a polymer in which the functionalized carbon compound is filled It is possible to provide a polymer-carbon composite material comprising a matrix containing a resin.

Specifically, in the group consisting of a hydroxyl group, a carboxyl group, a thiol group, a selenol group and an amino group on the surface carbon of the carbon compound When at least one of the aromatic and aliphatic compounds substituted with the at least one selected functional group is covalently bonded, the surface of the carbon compound is modified by the functional group, so that the carbon compound is not affected by steric hindrance or electrostatic repulsion such as van der Waals force, To provide a stable dispersing power in a polar solvent, and to provide a stable dispersing power in a polar polymer mattress of a composite material. The high reactivity of the functional groups can be utilized as an active site necessary for imparting functionalization of the carbon compound.

Also, at least one of the substituted aromatic and aliphatic compounds of the carbon compound may contain at least one selected from the group consisting of chlorine, azide, epoxide, cycloepoxide, acrylate, methaacrylate, Alkyne group, it is possible not only to induce various chemical reactions of the carbon compound according to the properties of the functionalizing functional groups, but also to increase the number of functional groups of the polar solvent (polar polymer resin) or The non-polar solvent (non-polar polymer resin) has a stable dispersing power. For example, a carbon compound functionalized with a halogen-based functional group such as chlorine can act as an active site that is highly reactive and can be substituted with various functional groups, and polar groups such as polar polymer resins such as polyimide resin polyimide and polyvinyl alcohol It has high dispersion power in resin. In the case of the azide functionalized carbon compound, it is dispersed well in the polar solvent due to the polarity of the azide and can have a stable dispersing power in the polar polymer resin. Since azide forms a covalent bond with the alkyne (CC triple bond) group, it forms a strong bonding force between the composite mattress of the polymer resin including the alkene group and the carbon compound as the filler, thereby providing enhanced mechanical properties can do. Epoxidized carbon compounds have a high dispersing power in epoxide polymer resins and can act as fillers to form strong bonds through chemical reactions and have improved mechanical properties. Acrylate and methacrylate, the acrylate and methacrylate polymer resins react with the polymer resin with high dispersibility in the polymer resin to form a strong bonding force with the filler and the composite material mattress to provide improved mechanical properties . Carbon compounds functionalized with alkyl groups are well dispersed in nonpolar solvents and are well dispersed in nonpolar polymer composite mattresses such as nonpolar polymer resin polyethylene, polypropylene, etc., and form strong bonds due to hydrophobic interaction, resulting in improved mechanical properties .

In one embodiment of the present invention, the functionalized carbon compound contained in the polymer-carbon composite material may be obtained by covalently bonding a compound having the following formula (1) to the surface carbon of the carbon compound, .

[Chemical Formula 1]

In Formula 1, R _{1 ,} R _{2 ,} R ₃ , R ₄ And R ₅ is one selected from the group consisting of -O-, -COO-, -S-, -Se-, -NH- and -H, and R _{6 ,} R _{7 ,} R ₈ , R ₉ And R ₁₀ is a group consisting of hydrogen, chlorine, azide, epoxide, cycloepoxide, acrylate, methacrylate, and alkyne groups. And n is an integer selected from 1 to 20. < RTI ID = 0.0 >

In one embodiment, the aromatic compound to be bonded to the functionalized carbon compound contained in the polymer-carbon composite material is not limited to its kind. Specifically, the aromatic compound may be substituted with a substance containing hydroxy, May be capable of introducing a period (-OH). For example, the functionalized carbon compound may be 4-aminophenol, that is, a compound wherein R ₇ is -O- and R ₁₀ is -NH- in the carbon surface carbon. In the case of a carbon compound, there is a phenomenon of recombination due to a strong binding force due to the above-described Valdervalence force and a π-π interaction. When 4-aminophenol is bonded, the surface of the carbon compound is modified. Therefore, the steric hindrance and the electrostatic repulsion The dispersing ability is improved in the polar solvent, and not only has a high dispersing power in the polar polymer resin, but also has improved mechanical properties by hydrogen bonding. The hydroxy group is a reactive group having various properties and is easy to substitute. The reaction also occurs near the edge of the graphene, reducing holes and defects on the surface of the graphene sheet, resulting in much better conductivity than graphene oxide made by the Hughes or Brody method.

In one embodiment of the present invention, the functionalized carbon compound contained in the polymer-carbon composite material may be selected from the group consisting of graphene, carbon nanotube, carbon fiber, and clay At least one selected from the group is functionalized. More specifically, the graphene may be graphene oxide obtained by removing graphene or oxidized graphene oxide from graphite without acid treatment by heat treatment or chemical treatment. The above-exemplified carbon compounds have low solubility and low dispersibility in various solvents or polymeric resins due to their inherent high-walledness, π-π interaction, and hydrophobic properties, so that cohesion is generated between carbon compounds, resulting in low mechanical and electrical properties However, such a problem can be solved by functionalizing and modifying the carbon compound according to the above embodiments of the present invention. In addition, when reduced graphene is used as an embodiment, the defects of graphene are complemented to form a sp ² carbon structure continuous to the graphene plate-like structure. Therefore, by overlapping the orbital orbital of pie-bonding, electric conductivity Can be greatly improved.

In one embodiment of the present invention, the polymer resin in which the functionalized carbon compound contained in the polymer-carbon composite material is filled is selected from the group consisting of polyimide, polyacrylonitrile, polyamide, polybenzoxazole, polybenzimidazole , Polyvinyl alcohol, polyethylene terephthalate (PET), polystyrene, and polymethylacrylate. The polymer resin may be at least one selected from the group consisting of a surface-modified carbon compound or a functionalized carbon compound and a composite material The type of the mattress (polymer resin) is not limited as long as it can improve the physical function by physicochemical reaction.

The functionalized carbon compound according to embodiments of the present invention may be filled in an amount of 0.1 to 30% by weight based on the total weight of the polymer resin. When the functionalized carbon compound is filled within the above range, the mechanical properties, electrical conductivity and economical efficiency of the polymer-carbon composite material can be optimized.

In addition, the polymer-carbon composite material according to embodiments of the present invention may be prepared by modifying the surface of a carbon compound with a compound substituted with various functional group groups such as a hydroxy group through a diazonium salt reaction , Functionalizing the modified carbon compound by binding a functional group containing a new function, and mixing the functionalized carbon compound with the polymer contained in the matrix of the composite material. As an example of the modification step, the surface of the carbon compound is modified with the amino group of 4-aminophenol. For example, the amino group of 4-aminophenol is reacted with a nitrosonium ion generated in NaNO ₂ The dehydration reaction generates a diazonium salt. At this time, electrons of the nucleophilic aromatic group of graphene bind to the generated carbon cations, so that graphene can be surface-modified with graphene having a hydroxy group. In addition to the amino group of the 4-aminophenol, various functional groups can be bonded to the surface of the graphene through the diazonium salt.

The method for producing a polymer-carbon composite material according to embodiments of the present invention includes the steps of: preparing a surface-modified carbon compound by covalently bonding a surface carbon of a carbon compound to a compound containing the following formula 2; to the covalent bond of the formula _{2 R 11, R 12, R} 13, R 14 And R ₁₅ (S) selected from the group consisting of chlorine, azide, epoxide, cycloepoxide, acrylate, methacrylate, and alkyne groups. Preparing a functionalized carbon compound by covalently bonding a compound containing the functional group of Formula 1 to a polymer precursor, a polymer resin, or a mixture thereof; And then filling the functionalized carbon compound into the polymer precursor, the polymer resin, or a mixture thereof, to prepare a polymer-carbon composite material. The formula (2) is as follows.

(2)

In Formula 2,

R _{11 ,} R _{12 ,} R ₁₃ , R ₁₄ And R ₁₅ is -OH, -COOH, -SH, -SeH, -NH ₂ And -H.

In one embodiment of the present invention, the polymer precursor specifically includes an anhydride diamine which is a precursor of polyimide, acrylonitrile which is a precursor of polyacrylonitrile, diamines and dihydroxy which are precursors of polyamide, Vinyl alcohol as a precursor of polystyrene, styrene as a precursor of polystyrene, and methacrylate as a precursor of polymethylacrylate. At this time, anhydride diamine, which is a precursor of polyimide, is one of polyamic acids having various monomers.

In one embodiment of the present invention, the polymer resin is selected from the group consisting of polyimide, polyacrylonitrile, polyamide, polybenzoxazole, polybenzimidazole, polyvinyl alcohol, polyethylene terephthalate (PET), polystyrene, ≪ / RTI >

In one embodiment, the polymer precursor, the polymer resin, or a mixture thereof is placed in a solution in which the functionalized carbon compound is dispersed and polymerized to polymerize the functionalized carbon compound into the polymer precursor, the polymer resin, or a mixture thereof. The step of preparing the compound composite material includes both polymer polymerization and packing at the same time depending on the type of the functional group that functions as the carbon compound, or filling the functionalized carbon compound into the polymer polymerized after the polymer polymerization. This can be selected depending on the properties of the functional group that functions the carbon compound, such as reaction with the polymer, hydrogen bonding, van der Waals force, hydrophobicity, electrostatic attraction, repulsion. That is, the in-situ method is advantageous if there is no effect on the degree of polymerization because the functionalized functional group is not reacted with the polymer to be filled, and if there is an influence on the degree of polymerization, a method of filling after polymerization is advantageous. In one embodiment, in the step of filling the functionalized carbon compound with the polymer precursor, the polymer resin, or a mixture thereof, the azide functionalized carbon compound may be prepared by polymerizing the polymer precursor, the polymer resin, or a mixture thereof, Then it can be done. For example, in the case of filling polyamic acid, it is possible to polymerize the monomers in situ without filling the carbon compounds after polymerization of PMDA (Puromellitic dianhydride), ODA (4,4-oxidaniline) and a-DBA (alkylated-diaminobenzoic acid) Method, azide reacts with the alkyne group introduced into the polymer chain to form a covalent bond during the imidization process, so that the degree of polymerization is lowered. In another embodiment, in the case of filling a carbon compound functionalized with an alkyl group that does not affect the degree of polymerization, the carbon compound is added to the solution together with the monomer and the polymer is polymerized by using an initiator or ultraviolet rays, Lt; RTI ID = 0.0 > in-situ < / RTI >

The step of preparing the polymer-carbon composite material according to embodiments of the present invention may further include a step of polymerizing the functionalized carbon compound with a polymer precursor, a polymer resin, or a mixture thereof, followed by heat treatment, It is possible to increase the mechanical strength of the finally formed polymer-carbon composite material by promoting the physicochemical reaction between the carbon compound and the polymer and forming a strong interfacial bond. In one embodiment, the heat treatment step may be performed at a temperature of 190 ° C to 400 ° C, more specifically 190 ° C to 210 ° C. When the heat treatment is performed within the temperature range, the covalent bond between the functionalized carbon compound and the polymer precursor, the polymer resin, or the mixture thereof can be prevented from being decomposed while appropriately inducing the reaction of the polymer.

In addition, the step of preparing the polymer-carbon composite material according to embodiments of the present invention can lower the polymerization reaction temperature by adding a basic catalyst upon polymerization of a functionalized carbon compound, a polymer precursor, a polymer resin, or a mixture thereof have. The basic catalyst is not limited as long as it can lower the polymerization reaction temperature of the polymer and the carbon compound. For example, 1,4-diazabicyclo [2.2.2] octane, 1,4-diazabicyclo [ , 2,3,4,6,7,8,9,10-octahydropyrimido [1,2-a] azepine (2,3,4,6,7,8,9,10-Octahydropyrimido [1 , 2-a] azepine, 4-hydroxypyridine, and the like. Conventionally, in the case of a polymerization reaction, a high temperature condition of 300 ° C or more is required. Under these conditions, functional groups of the functionalized carbon compound are decomposed. However, by further adding the basic catalyst to the polymerization process as described above, the polymerization reaction can be performed at around 200 ° C, thereby preventing the problem of decomposing functional groups of the functionalized carbon compound.

According to further embodiments of the present invention, at least one of the steps of preparing the surface-modified carbon compound, preparing the functionalized carbon compound, and producing the polymer-carbon composite material may be performed by dispersing and homogenizing the carbon compound, And increasing the surface area of the compound. For example, in one embodiment, the carbon compound may be dispersed and homogenized by applying a shear in the circumferential direction using a homogenizer. According to the present invention, when a carbon material is physically and chemically bonded to a polymer precursor, a polymer resin, or a mixture thereof, the carbon material in the polymer material must be uniformly dispersed to form a conductive channel. That is, the physical properties, particularly the electrical conductivity, of the final composite material are determined depending on whether the degree of dispersion is uniform or not. In the case of the conventional ultrasonic method, a carbon compound having a small surface area is formed by forming a bond on the surface of a carbon compound and then cutting it, which is a disadvantage in forming a conductive channel in a polymer material. However, in the present invention, the carbon compound is homogenized in the circumferential direction by using a homogenizer in the step of producing the surface-modified carbon compound, the step of producing the functionalized carbon compound and the step of producing the polymer-carbon composite material, It is possible to minimize the bonding of the surface of the compound and to produce a large-area carbon compound sheet such as a graphene sheet. In addition, the conductive channel is well formed in the polymer material, and the problems of the prior art can be solved.

Hereinafter, the present invention will be described with reference to the following examples and experimental examples. The Examples and Experimental Examples are intended to further illustrate the present invention and are not intended to limit the scope of the present invention. In addition, the comparative example described below is described only for the purpose of comparison with the embodiments, and is not described as a conventional technique. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit of the invention.

[Example 1] Production of polymer-carbon composite material

The polymer-carbon composite material according to one embodiment of the present invention was prepared by the following method.

First, 1 g of graphite (CM-250, XG-Science, USA) and 5 g of NaClO ₃ were added to a 100 ml nitric acid solution and stirred at room temperature for 48 hours. The reaction product was washed with distilled water (DI-water), and the reaction product was dried at 60 ° C for 24 hours to prepare graphene oxide. The graphene oxide was heat-treated at 1500 ° C for 1 hour to prepare graphene .

Then, 0.1 g of the graphene was added to 100 mL of sulfuric acid solution and ultrasonically dispersed for 30 minutes. The ultrasonic dispersed graphene solution was added to the reaction tank, and the temperature of the reaction tank was set to 60 캜. When the temperature of the reaction vessel is a 60 ℃, after the addition of NaNO _2, 3g of 4- aminophenol of 1g it was reacted by stirring for 10 hours over 60 ℃. The stirred mixture was cooled to room temperature and washed with a solution of N, N-dimethylmethanamide (DMF) to remove unreacted materials. Then, the mixture was washed with ethanol to remove residual DMF and dried at 60 ° C in a vacuum oven. - Surface modified graphenes in which aminophenols were bonded to surface carbon were prepared.

In order to functionalize the graphene surface-modified with the hydroxy group, 1 g of the graphene modified with the hydroxy group was dispersed in 60 ml of solvent DMF for 1 hour to disperse it. 14.8 g of K ₂ CO ₄ and 8.9 ml Of Br (CH ₂ ) ₂ Cl was added. After the reaction was completed, the reaction mixture was poured into 50 ml of distilled water and stirred at room temperature for 1 hour. Then, 150 ml of CH ₂ Cl ₂ was added to the distilled water to which the mixture had been added three times, and the mixture was extracted three times. Na ₂ SO ₄ was added and the mixture was stirred at room temperature for 30 minutes to remove the residue. The Na ₂ SO _{4 was} then filtered and dried to produce graphene functionalized with chlorine.

Then, in order to replace the graphene functionalized with the chlorine group with the azide group, 1 g of graphene functionalized with a chlorine group was dispersed in 60 ml of DMF solvent for 1 hour by ultrasonication. The dispersed solution was adjusted to 60 캜, and 2.6 g of NaN ₃ was added, followed by stirring at 60 캜 for 24 hours. The reacted mixture was poured into 50 ml of distilled water, stirred for 1 hour, and extracted with 150 ml portions of CH ₂ Cl ₂ three times. Na ₂ SO ₄ was added and stirred for 30 minutes to remove the residue, followed by filtration and drying to obtain graft functionalized with an azide group. The functionalized graphene produced was called N ₃ -Ph-TGO.

On the other hand, 10 g of diaminobenzoic acid was added to 80 ml of DMF in order to prepare a monomer containing an alkyl group necessary for the production of polyamic acid (PAA) which is a precursor of polyimide. Here, K ₂ CO ₃ And the mixture was heated at 70 ° C for 10 minutes, and then cooled to room temperature. Next, 7.3159 ml of bromopropylglyle was added and the reaction was allowed to proceed at 80 ° C for 4 hours. The DMF solvent was then dried, and the monomer was extracted with EA (ethyl acylate) by adding distilled water. Na ₂ SO ₄ was added to remove the residue, and the impurities were removed through a filter. The monomer was isolated through a column and dried to produce an alkylated-diaminobenzoic acid (a-DBA). 1A to 1C show results of analysis of the monomer (a-DBA) by FT-IR, H ¹ -NMR and C ¹³ -NMR, respectively.

The sp CH vibration motion of the alkyne group, which can not be confirmed by the diaminobenzoic acid, was found to be 3286 cm and the CC triple bond vibration peak at 2113 cm- ¹ in the alkyne group through the FT-IR spectrum of FIG. 1A, indicating that the diaminobenzoic acid had an alkylate . The exact structure was confirmed by NMR data. Figures 1B and 1C are analyzes of alkylate diamine benzoic acid. Hydrogen, Carbon NMR confirmed the a-DBA by confirming the peak appearing in the alkyne group and confirming the exact structure.

Then, 1.74 g of the alkylated-diaminobenzoic acid (a-DBA), 5 g of PMDA (pomellitic dianhydride), 4,4'-oxidaniline, ODA ) And 1.74 g of DABCO (1,4-Diazabicyclo [2,2,2] octane) were stirred and polymerized for 24 hours to prepare a polyimide precursor polyamic acid (PAA). The prepared polyamic acid was precipitated in a solution of water: methanol at a ratio of 9: 1, and then dried at 60 DEG C to obtain a powdery polyamic acid. As a result, an active site capable of reacting with the azide group of the graphene and the polymer chain was introduced into the polymer.

5.7 g of the prepared graphene N ₃ -Ph-TGO was added to 33.67 g of 1-methyl-2-pyrrolidinone (NMP) and dispersed for 1 hour using a homogenizer to prepare a solution in which graphene was dispersed Respectively. Then, 1 g of the prepared polyamic acid (PAA) was added and stirred for 24 hours to prepare a polyamic acid precursor filled with graphene functionalized with an azide group. The polyamic acid precursor filled with the functionalized graphene thus prepared was subjected to heat treatment at 90 ° C for 4 hours to remove the remaining solvent (Drying and Curing), and then the temperature was raised to 200 ° C stepwise and imidized for 1 hour for functionalization A polyimide composite material filled with graphene was produced. FIG. 2 shows a series of processes for preparing polyamic acid filled with functionalized graphene by reacting the polyamic acid with a solution containing graphene N ₃ -Ph-TGO. In this case, the structural formula represented by PI represents a structural formula changed from a polyamic acid to a polyimide after heat treatment of the composite mattress, and a structural formula expressed below is a covalent bond by a click reaction during the heat treatment process of graphene and a composite mattress. It is a representation of what is formed.

[Comparative Example 1] Production of reducing graphene

As a comparative example of the present invention, reduced graphene not functionalized was prepared by the following method.

First, 1 g of graphite (CM-250, XG-Science, USA) and 5 g of NaClO ₃ were added to a 100 ml nitric acid solution and stirred at room temperature for 48 hours. The reaction product was washed with distilled water (DI-water), and the reaction product was dried at 60 ° C. for 24 hours to prepare graphene oxide. Then, the graphene oxide was heat-treated at 1500 ° C for 1 hour to prepare graphene. The graphene was called TGO.

[Comparative Example 2] Production of pure polyimide

As a comparative example of the present invention, pure polyamic acid was prepared by the following method.

First, 2.74 g of 4,4'-oxydianiline and 1.74 g of alkylated-diaminobenzoic acid were added to 33.67 g of 1-methyl-2-pyrrolidinone (NMP) And dissolved in NMP solvent. To the solution thus dissolved was added 1 wt% of DABCO (1,4-diazabicyclo [2.2.2] octane) to the weight ratio of oxydianiline, alkylate-diaminobenzoyl-acid and pyromellitic dianhydride And stirred for 10 minutes. After stirring was completed, 5 g of pyromellitic dianhydride was added and stirred for 24 hours to prepare polyamic acid as a polyimide precursor.

Next, 1 g of the polyamic acid prepared above was re-dissolved in 9.09 g of 1-methyl-2-pyrrolidinone (NMP), cast on the PI film, and heat-treated at 90 ° C for 4 hours. The remaining solvent was blown off, The polyimide was prepared by a stepwise heat treatment.

[Experimental Example 1] Functionalization of carbon compounds

In order to confirm the surface modification and functionalization of the carbon compound packed in the polymer-carbon composite material according to one embodiment of the present invention, the following experiment was conducted.

First, Example 1 (N ₃ -Ph-TGO), which is graphene functionalized with an azide group, Example 2 (OH-), which is graphene functionalized in the same manner as in Example 1, Ph-TGO), Comparative Example 1 (TGO), which is a surface-modified and nonfunctionalized reduced graphene, OH-TGO, which is a non-functionalized carbon compound after surface modification with a hydroxy group in the same manner as in Example 1, The functionalized carbon compounds Cl-TGO and N ₃ -TGO were prepared in the same manner as in Example 1, respectively.

Then, the characteristics of each of the carbon compounds were analyzed.

FT - IR analysis

Example 2 (OH-Ph-TGO) , it exhibited a Cl-TGO and N ₃ -TGO the FT-IR analysis to Figure 3a, respectively.

From FIG. 3A, it is possible to confirm the OH characteristic peak of the three carbon compounds at 3400 cm ^-1 . And Cl-TGO from OH characteristic peak, 805 cm ^-1 at 3400cm ^-1 has a characteristic peak in the C-Cl, N _3, N in -TGO OH characteristic peaks, 2100 and 1350 cm ^-1 at 3400cm ^-1 = N = N. However, since the functionalized graphene of Example 2 (OH-Ph-TGO) has only an OH characteristic peak at 3400 cm ^-1 , the functionalization of Example 2 (OH-Ph-TGO) Respectively.

Raman analysis

Comparative Example 1 (TGO), OH-TGO, Cl-TGO and N ₃ -TGO were analyzed by Raman analysis and shown in FIG. From FIG. 3b, the D and G peaks of the three carbon compounds can be confirmed. At this time, the surface modification by a hydroxy group in a TGO of graphene-OH TGO, the yes-functionalized group is Cl-TGO and azide groups functionalized pin chlorine yes A comparison of the G peak position of the pin is N ₃ -TGO 2 ~ 4cm ^{- 1} < / RTI > peak.

The I _D / I _G ratio (raio) and G band position of Comparative Example 1 (TGO), OH-TGO, Cl-TGO and Example 1 (N ₃ -Ph-TGO) Respectively.

Sample I _D / I _G ratio G-band position Comparative Example 1 (TGO) - 1578 OH-TGO 0.51 1573 (-5 cm ^-1 ) Cl-TGO 0.49 1580 (+ 2 cm ^-1 ) Example 1 (N ₃ -Ph-TGO) 0.50 1582 (-4 cm ^-1 )

From Table 1, it can be seen that the I _D / I _G ratio is almost unchanged as OH-TGO is 0.51, Cl-TGO is 0.49 and N ₃ -TGO is 0.50. In the case of Example 1 (N ₃ -Ph-TGO), surface modification with a hydroxy group through a diazonium sulfate reaction followed by action of a hydroxyl group as a reaction site resulted in functionalization with azide without generating additional defects on the graphene surface It means that it is done.

XPS Elemental analysis

Example 2 (OH-Ph-TGO) and N ₃ -TGO were subjected to XPS element analysis, respectively, and are shown in FIG. 3c. From FIG. 3C, it was confirmed by comparison of Example 2 (OH-Ph-TGO) and N ₃ -TGO through analysis of the composition of XPS that nitrogen (N) not identified in Example 2 (OH-Ph-TGO) It can be confirmed that the azide functionalization has been successfully accomplished through the above series of functionalization. In the XPS survey mode, the intensity depends on the elemental content. In the case of N ₃ -TGO, the nitrogen content is 3.6% as shown in Table 2, so that the intensity is low, but the characteristic peak of the nitrogen element appears as shown in the upper right graph of FIG. 3c. Therefore, it can be confirmed that graphene is functionalized with azide.

The contents of the elements after the analysis of the XPS element of Example 2 (OH-Ph-TGO) and N ₃ -TGO are summarized in Table 2 below.

Sample Atomic concentration (%) C O N S Example 2 (OH-Ph-TGO) 87.65 12.35 0 0 N ₃ - TGO 79.58 16.76 3.65 0

Table 2 shows the contents of Example 2 (OH-Ph-TGO) and N ₃ -TGO nitrogen, and it can be confirmed that the nitrogen content of N ₃ -TGO is 3%. This means that the azide functionalization is about 1% of the elemental azide.

[Experimental Example 2] Comparison of dispersibility of carbon compounds

The following experiments were conducted to confirm the surface modification of the polymer-carbon composite material according to one embodiment of the present invention and the dispersibility of the functionalized carbon compound.

Specifically, the dispersity of the functionalized graphene of Example 1 (N ₃ -Ph-TGO) and the nonfunctionalized graphene of Comparative Example 1 (TGO) in DMF solvent was measured by ultraviolet And measured using a visible light NIR spectrophotometer (UV / VIS / NIR Spectrophotometer V-670). The results are shown in Table 3 and FIG. 4, respectively.

division Dispersion degree (mg / mL),? = 550 nm R ² Example 1 (N ₃ -Ph-TGO) 3.9 0.93 Comparative Example 1 (TGO) 2.9 0.98

From Table 3 and FIG. 4, it can be seen that the functionalized graphene prepared by the method according to the present invention (Example 1) has a significantly higher degree of dispersion than reduced graphene (Comparative Example 1) . This is because the present invention improves the problem that the dispersibility in the composite material is low when the carbon compound such as graphene is filled in the polymer resin, thereby reducing the mechanical properties of the composite material, by surface modification and functionalization of the carbon compound as a functional group .

[Experimental Example 3] Comparison of mechanical properties

In order to compare and confirm the change of the mechanical properties of the composite material depending on the content of the surface modified and functionalized carbon compound packed in the polymer-carbon composite material according to an embodiment of the present invention, the following experiment was conducted.

Specifically, Example 3 in which functionalized graphene as a polymer-carbon composite material prepared in the same manner as in Example 1 was filled in 0.5 wt%, 1 wt%, and 3 wt% based on the total weight of the polyimide, 4 and 5, and the pure polyimide (Comparative Example 2) were measured and compared. The instrument used for the experiment was a universal testing machine (UTM), 5567A, Instron, USA, and the measurement results are shown in Table 4 and FIG.

division Graphene content (% by weight) Tensile Strength (MPa) Modulus of Elasticity (GPa) Comparative Example 2 (Pure PI) 0 82.71 + - 9.64 2.83 ± 0.22 Example _{3 (N 3 -Ph-TGO /} PI) 0.5 100.10 + - 2.83 2.83 ± 0.09 Example _{4 (N 3 -Ph-TGO /} PI) One 104.85 ± 2.18 3.03 0.11 Example _{5 (N 3 -Ph-TGO /} PI) 3 87.98 ± 2.18 3.08 ± 0.31

From Table 4 and FIG. 5, it can be seen that the mechanical properties of the composite material according to the present invention are increased as the content of functionalized graphene is increased. In particular, in the case of a composite material containing 1% by weight of functionalized graphene, the tensile strength was improved by more than 28% from about 82 MPa to about 105 MPa, and the elastic modulus was increased from about 2.83 GPa to about 3.08 GPa by 9% Or more.

This is because when the functionalized carbon compound is filled in the polymer resin, a covalent bond is formed by a click reaction between the functional group of the carbon compound and the polymer chain, and the carbon compound and the polymer are reacted at a relatively low temperature It is prevented that the interfacial bond between the carbon compound and the polymer is decomposed, and thus a composite material having high strength and high modulus of elasticity is produced.

Claims (10)

A compound having the following formula (1) is covalently bonded to the surface carbon of at least one carbon compound selected from the group consisting of Graphene, Carbon nanotube, Carbon fiber and Clay, Carbon compounds; And
(PET), polystyrene, and polymethylacrylate, in which the functionalized carbon compound is filled, wherein the functionalized carbon compound is filled with a polymer selected from the group consisting of polyimide, polyacrylonitrile, polyamide, polybenzoxazole, polybenzimidazole, polyvinyl alcohol, polyethylene terephthalate Polymer-carbon composite material comprising a matrix comprising at least one polymeric resin selected from the group consisting of:
[Chemical Formula 1]

In Formula 1,
R _1, R _2, R ₃ , R ₄ and R ₅ are each independently selected from the group consisting of -O-, -COO-, -S-, -Se- and -NH-,
R _6, R _7, R ₈ , R ₉ and R ₁₀ are independently selected from the group consisting of hydrogen, chlorine, azide, epoxide, cycloepoxide, acrylate, methacrylate ) And an alkyne group,
and n is an integer selected from 1 to 20. [ The polymer-carbon composite material according to claim 1, wherein the functionalized carbon compound is 4-aminophenol bonded to the carbon surface carbon. The method according to claim 1,
Wherein said graphene is graphene oxide obtained by removing graphene or oxidized graphene oxide from graphite without being subjected to an acid treatment by heat treatment or chemical treatment. The method according to claim 1,
Wherein the functionalized carbon compound is filled in an amount of 0.1 to 30% by weight based on the weight of the polymer resin. A method of producing a polymer-carbon composite material according to any one of claims 1 to 4,
Covalently bonding the surface carbon of the carbon compound to a compound containing the following formula 2 to prepare a surface-modified carbon compound;
_At least one of R _11, R _12, R ₁₃ , R ₁₄ and R ₁₅ covalently bonded to the surface-modified carbon compound is reacted with at least one of chlorine, azide, epoxide, (1) is covalently bonded to at least one functional group selected from the group consisting of cycloepoxide, acrylate, methacrylate, and alkyne group to form a functionalized carbon compound Lt; / RTI > And
Preparation of a polymer-carbon composite material in which a polymer precursor, a polymer resin, or a mixture thereof is put into a solution in which the functionalized carbon compound is dispersed and polymerized to fill the functionalized carbon compound into the polymer precursor, the polymer resin or a mixture thereof Comprising:
Wherein the polymer precursor is at least one selected from the group consisting of anhydride diamine, acrylonitrile, diamine, dihydroxy, vinyl alcohol, styrene, and meta methyl acrylate, and the polymer resin is at least one selected from the group consisting of polyimide, A method for producing a polymer-carbon composite material having at least one selected from the group consisting of nitrile, polyamide, polybenzoxazole, polybenzimidazole, polyvinyl alcohol, polyethylene terephthalate (PET), polystyrene and polymethylacrylate,
(2)

In Formula 2,
R _11, R _12, R ₁₃ , R ₁₄ and R ₁₅ are each selected from the group consisting of -OH, -COOH, -SH, -SeH and -NH ₂ . [7] The method of claim 5, wherein the step of preparing the polymer-carbon composite material further comprises polymerizing the functionalized carbon compound with a polymer precursor, a polymer resin or a mixture thereof, and then heat- Method for manufacturing carbon composite material. The method according to claim 6, wherein the temperature of the heat treatment step is 190 ° C to 400 ° C. 6. The method of claim 5, wherein the polymer-carbon composite material is prepared by polymerizing a functionalized carbon compound, a polymer precursor, a polymer resin, or a mixture thereof, A method for producing a composite material of a carbon compound. 6. The method of claim 5, wherein at least one of the steps of preparing the surface-modified carbon compound, preparing the functionalized carbon compound, and producing the polymer-carbon composite material comprises dispersing and homogenizing the carbon compound to increase the surface area of the carbon compound Wherein the method further comprises the step of:
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