KR20230115555A - Polymer nanocomposite comprising graphene nanoplatelet and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a polymer nanocomposite composition containing: a polymer compound comprising at least one selected from a group consisting of thermoplastic polymers and thermosetting polymers; and graphene nanoplatelets. In the polymer nanocomposite composition containing the graphene nanoplatelets of the present invention and a manufacturing method thereof, the polymer nanocomposite composition can be manufactured economically and eco-friendly through mechanical peeling, and by mixing the graphene nanoplatelets and the polymer compound, mechanical properties are improved to be used as materials for various construction materials, lightweight automobile parts, electronic/electrical parts and the like.

Description

Polymer nanocomposite composition containing graphene nanoplatelets and method for preparing the same

The present invention relates to a polymer nanocomposite material composition containing graphene nanoplatelets and a method for preparing the same, and more particularly, to a polymer nanocomposite composition containing graphene nanoplatelets prepared through mechanical exfoliation and having improved mechanical properties. It is about.

Polymer nanocomposites are manufactured using carbon-based nanomaterials and polymers, such as expandable graphite, carbon nanotubes (CNT), carbon nanofibers (CNF), fullerenes, and graphene (single-layer and multi-layer). By doing so, relatively inexpensive graphene nanoplatelet compared to expensive carbon nanotubes can be mixed with polymers and used.

Graphene refers to a single-layer two-dimensional (2D) sheet arranged in a honeycomb structure with sp ² hybridization of carbon. there is. Graphene, a 2D structure, has excellent mechanical, thermal and electrical properties and can be chemically or mechanically separated from 3D graphite, intercalation graphite (Graphite Intercalation Compounds) or expanded graphite to obtain multi-layer and mixtures of multi-layer graphene. In particular, monolayer graphene has characteristics such as bipolar electric field effect, quantum Hall effect, monomolecular adsorption, and high carrier mobility (up to 230,000 cm ² /Vs) at room temperature, so that it can be used for high-speed and radio frequency logic devices, sensors, and transparent electrodes. , displays, touch screens, solar cells, fuel cells (electrode conductive additives and separators), etc. Single-layer graphene has very large charge mobility (230,000 cm ² /Vs), electrical conductivity (7200 S/m), visible light absorption of 2.3% (i.e. high transparency), high thermal conductivity (3000 W/mK), excellent It is a dream material with tensile strength (130 GPa), tensile modulus (1 TPa), and large specific surface area (theoretical value of 2600 m ² /g). However, until now, no method has been found to obtain single-layer graphene in large quantities by mechanical exfoliation. However, it is possible to prepare polymer nanocomposites dispersed in a single layer of solution blending or in situ polymerization (epoxy, styrene, etc.) with a polymer using graphene oxide manufactured by a chemical exfoliation method. When graphene oxide dispersed in a single layer is reduced, it is difficult to prevent the phenomenon of restacking into multiple layers again by van der Waals force.

In addition, the classification of graphene or graphene nanoplatelets is determined by the thickness, and pure graphene is a single layer with a thickness of 0.33 nm, or two layers (about 0.7 nm), three layers (about 1 nm), and several layers (2 to 5 layers). , or multi-layers (2 to 10 layers), and if it is not a single layer, it can be classified as the average value or distribution of the mixture. In addition, the graphene nanoplatelet may be determined to be 10 layers (3.34 nm) or more. Single-layer graphene can be obtained mainly by chemical vapor deposition. This method is mainly used to make a single-layer graphene film on glass or polymer substrates used for displays and touch screens, and is used in single-layer as well as multi-layer areas. This is not a suitable method due to low yield and high manufacturing cost to be mixed and used as a reinforcing agent in powder form.

In addition, graphene nanoplatelets can be added to polymers to enhance mechanical properties, but in most polymer nanocomposites, as the content of graphene nanoplatelets increases, brittleness increases, and tensile strength and flexural strength tend to decrease. It was observed that processability decreased due to increase in viscosity.

Korean Registered Patent No. 10-2253218 (2021.5.12)

An object of the present invention is to provide a polymer nanocomposite material composition with improved mechanical properties including graphene nanoplatelets prepared economically and environmentally friendly through mechanical exfoliation and a method for preparing the same.

In addition, an object of the present invention is to include a graphene nanoplatelet that can be used as a material for various construction materials, lightweight automobile parts, electronic / electrical parts, etc. by mixing the graphene nanoplatelet and the polymer compound to improve mechanical properties. It is to provide a polymer nanocomposite material composition and a manufacturing method thereof.

According to one aspect of the present invention, a polymer compound comprising at least one member selected from the group consisting of a thermoplastic polymer and a thermosetting polymer; and graphene nanoplatelets; There is provided a polymer nanocomposite material composition comprising a.

In addition, the polymer compound may be a PC/ABS compound including polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS).

According to another aspect of the present invention, (a) heat-treating a first mixture containing graphite to prepare expanded graphite; (b) preparing a second mixture by mixing the expanded graphite and an organic binder; and (c) preparing a graphene nanoplatelet by grinding the second mixture.

Also, in step (a), the first mixture may include an acid material, and the acid material may include sulfuric acid or nitric acid.

In addition, after step (a), (a') preparing expanded graphite having a high apparent density by pulverizing the expanded graphite; may be further included.

In addition, in step (b), the organic binder is sugar, oligosaccharide, malt, poly (ethylene glycol), methoxy poly (ethylene glycol), dimethoxy poly (ethylene glycol), poly (propylene glycol), methoxy poly ( propylene glycol), dimethoxy poly(propylene glycol), poly(vinyl alcohol), poly(vinyl acetate), polyolefin, oxidized polyolefin, and wax.

In addition, step (c) is (c-1) preparing a pulverized mixture by pulverizing the mixture; and (c-2) preparing graphene nanoplatelets by removing organic binders from the pulverized mixture.

In addition, after step (c), (d) adjusting the particle size of the graphene nanoplatelet to prepare a graphene nanoplatelet having a controlled particle size; may be further included.

According to another aspect of the present invention, (a) manufacturing a graphene nanoplatelet according to the manufacturing method of the graphene nanoplatelet; and (b) preparing a polymer nanocomposite composition by mixing a polymer compound containing at least one selected from the group consisting of a thermosetting polymer and a thermoplastic polymer and the graphene nanoplatelet. A manufacturing method is provided.

The polymer nanocomposite material composition including graphene nanoplatelets and the manufacturing method thereof according to the present invention can economically and eco-friendlyly manufacture graphene nanoplatelets through mechanical exfoliation.

In addition, the polymer nanocomposite material composition including the graphene nanoplatelets and the manufacturing method thereof according to the present invention have improved mechanical properties by mixing the graphene nanoplatelets and the polymer compound, and thus various construction materials, lightweight automobile parts, electronic// It can be used as a material for electrical parts, etc.

1 is a flow chart of a method for manufacturing a graphene nanoplatelet according to the present invention.
2 is a scanning electron micrograph of expanded graphite used in any one example of the present invention.
3 is a scanning electron micrograph of a silicon millstone device (left) used in one embodiment of the present invention and expanded graphite pulverized through the silicon millstone device.
4 is a scanning electron micrograph of a graphene nanoplatelet according to the present invention.

Since the present invention can apply various transformations and have various embodiments, specific embodiments are exemplified and described in detail in the detailed description. However, it should be understood that this is not intended to limit the present invention to specific embodiments, and includes all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Also, terms including ordinal numbers such as first and second to be used below may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention.

Also, when a component is referred to as “on another component,” “formed on another component,” “located on another component,” or “stacked on another component,” the other It should be understood that although it may be directly attached to the front surface or one side of the component, it may be positioned or laminated, but other components may further exist in the middle.

Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, a polymer nanocomposite material composition including graphene nanoplatelets will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

The present invention is a polymer compound comprising at least one member selected from the group consisting of a thermoplastic polymer and a thermosetting polymer; It provides a polymeric nanocomposite composition comprising; and graphene nanoplatelets.

The polymer compound may be a PC/ABS compound including polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS).

The polymer nanocomposite material composition may include 0.01 to 20 parts by weight, preferably 0.05 to 5 parts by weight, more preferably 0.1 to 0.5 parts by weight of the graphene nanoplatelets, based on 100 parts by weight of the polymer compound. .

With respect to 100 parts by weight of the polymer compound, if the graphene nanoplatelet is included in an amount of less than 0.01 part by weight, it is not preferable because physical property improvement is insignificant, and if it is included in an amount exceeding 20 parts by weight, the viscosity is not preferable because it is very high.

At least one selected from the group consisting of an antioxidant, a light stabilizer, a heat stabilizer, a reinforcing agent, an anti-slip agent, an antibiotic, a colorant, a flame retardant, a surfactant, a coupling agent, an impact modifier, a fiber reinforcing agent, and an antiwear agent may additionally be included.

The PC/ABS compound further includes a flame retardant, and the PC/ABS compound comprises 40 to 80% by weight of the polycarbonate, 5 to 30% by weight of the acrylonitrile-butadiene-styrene copolymer, and 5 to 80% by weight of the flame retardant. 30% by weight.

The flame retardant may include bisphenol diphenyl phosphate.

1 is a flow chart of a method for manufacturing a graphene nanoplatelet according to the present invention. Hereinafter, a method for manufacturing a graphene nanoplatelet will be described in detail with reference to FIG. 1 . However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

First, expanded graphite is prepared by heat-treating a first mixture including graphite (step a).

In step (a), the graphite may include at least one selected from the group consisting of expanded graphite, impression graphite, graphite intercalation compounds, and mixtures thereof, and preferably, the graphite is expanded graphite. can include

In step (a), the first mixture may include an acid material, the acid material may include sulfuric acid or nitric acid, and the acid material may be intercalated between layers of the graphite.

In step (a), the acid material may be removed from the expanded graphite due to the heat treatment.

In step (a), the heat treatment may be performed at 300 to 1,000° C. for 10 to 300 minutes. A heat treatment temperature of less than 300° C. is undesirable because the graphite cannot sufficiently expand or acid materials (sulfuric acid or nitric acid) cannot be removed, and a temperature of more than 1,000° C. is undesirably high and thus uneconomical. In addition, a heat treatment time of less than 10 minutes is not preferable because acid substances (sulfuric acid or nitric acid) cannot be removed, and a heat treatment time of more than 300 minutes is undesirably long and uneconomical.

After step (a), (a′) preparing expanded graphite having a high apparent density by pulverizing the expanded graphite; may be further included.

The expanded graphite of step (a) may have an apparent density of 0.01 to 0.05 g/cm ³ , and the expanded graphite having an increased apparent density of step (a′) may have an apparent density of 0.1 to 0.5 g/cm ³ . .

The expanded graphite in step (a) has a very low density and is difficult to mix with the organic binder, so when it is pulverized using a silicon millstone device (FIG. 2) to increase the apparent density, the laminated structure of the expanded graphite is broken and the apparent density is increased, and mixing with the organic binder, which is the next step, may be easier.

The silicon millstone device is a device in which two silicon disks are manufactured in a millstone-like structure and expanded graphite is passed between the two plates, and the shear force is low, so the grinding effect or the peeling effect is not great. Ball mill, air mill instead of silicon milling device to increase grinding and peeling effect while increasing apparent density. An air-jet mill, a planetary mill, a bead mill, or an attrition mill may be used. Also, it is possible to use a traditional millstone instead of a silicon millstone device. In this case, a motorized millstone is preferred over a manual one.

Next, a second mixture is prepared by mixing the expanded graphite and the organic binder (step b).

In step (b), the organic binder is sugar, oligosaccharide, malt, poly (ethylene glycol), methoxy poly (ethylene glycol), dimethoxy poly (ethylene glycol), poly (propylene glycol), methoxy poly (propylene glycol) ), dimethoxy poly(propylene glycol), poly(vinyl alcohol), poly(vinyl acetate), polyolefin, oxidized polyolefin, and wax. The organic binder is preferably water-soluble, and preferably has a melting temperature or liquefaction temperature between 30°C and 200°C, more preferably between 60°C and 150°C. In addition, when the organic binder is water-soluble, it can be easily removed by dissolving in water, and when the remaining amount of ash is less than 5% by weight, it can be easily removed by heat treatment or combustion.

In step (b), the second mixture is 10 to 60% by weight of the expanded graphite; and 40 to 90% by weight of the organic binder; It may include, preferably 20 to 40% by weight of the expanded graphite; and 60 to 80% by weight of the organic binder; can include

If the second mixture contains less than 10% by weight of the expanded graphite, it is undesirably too hard and inefficient, and if it contains more than 60% by weight, it is brittle and undesirable. If the second mixture contains less than 40% by weight of the organic binder, it is not preferable because it is easily brittle, and if it contains more than 90% by weight, it is difficult to polish.

In step (b), the mixing may be performed at 100 to 200 rpm for 5 to 30 minutes.

Finally, the second mixture is pulverized to prepare graphene nanoplatelets (step c).

In step (c), the grinding is performed by a ball mill or an air mill. Air-jet mill (air-jet mill), planetary mill (planetary mill), bead mill (bead mill), attrition mill (attrition mill), or may be carried out by any one selected from the group consisting of a nano grinder.

The mixture can be easily pulverized into powder with a grinding machine attached with sanding paper between 40 mesh (room) and 600 mesh. The closer to 40 mesh, the coarser and faster the grinding speed, and the closer to 600 mesh, the softer finely ground A traditional powered millstone can also be used instead of a grinder.

Step (c) is (c-1) preparing a pulverized mixture by pulverizing the second mixture; and (c-2) preparing graphene nanoplatelets by removing organic binders from the pulverized mixture.

The organic binder contained in the pulverized mixture can be easily removed by washing with water, heat treatment, or burning. In the case of a water-soluble organic binder, it is dissolved in water, filtered, continuously washed with water, and then dried to remove the water-soluble organic binder, and to obtain graphene nanoplatelets in a rather rough state with a large diameter and little or almost no ash. In the case of an organic binder, graphene nanoplatelets can be obtained by removing the organic binder through the same heat treatment (600° C., 30 minutes or more) as in step (a) or a combustion process in air.

In step (c), the diameter of the graphene nanoplatelet may be 10 to 150 μm, and the thickness of the graphene nanoplatelet may be 5 to 50 nm.

After step (c), (d) adjusting the particle size of the graphene nanoplatelet to prepare a graphene nanoplatelet having a controlled particle size; may be further included.

In step (d), the diameter of the graphene nanoplatelet whose particle size is controlled may be 1 to 30 μm, and the thickness of the graphene nanoplatelet whose particle size is controlled may be 1 to 10 nm.

Step (d) is a ball mill, an air mill. Graphene nanoplatelets in a rough state are prepared using an air-jet mill, planetary mill, bead mill, attrition mill, or nano mill. It may be a step of preparing a graphene nanoplatelet having a diameter of 25 μm or less and a thickness of 10 nm or less.

The graphene nanoplatelet having a controlled particle size may be directly used as a polymer reinforcing agent, or may be used as a polymer reinforcing agent after being sieved or classified. Graphene nanoplatelets with a 100 mesh sieve of 150 μm or less, a 325 mesh sieve of 44 μm or less, and a 500 mesh sieve of 25 μm or less can be obtained. For mass production, other classifiers are also available, such as various open or closed circuit sieves classifiers with cyclone technology.

Hereinafter, a method for manufacturing a polymer nanocomposite material including a method for manufacturing a graphene nanoplatelet will be described in detail.

The present invention includes (a) preparing a graphene nanoplatelet according to the manufacturing method of the graphene nanoplatelet; and (b) preparing a polymer nanocomposite composition by mixing a polymer compound containing at least one selected from the group consisting of a thermosetting polymer and a thermoplastic polymer and the graphene nanoplatelet. A manufacturing method is provided.

In step (b), (b-1) preparing a mixture by mixing the graphene nanoplatelets and the polymer compound; and (b-2) preparing a polymer nanocomposite material composition by injecting the mixture.

After step (b-1), (b-1-1) preparing an extrusion-kneaded mixture by extrusion-kneading the mixture; may further include.

In step (b-1-1), the twin-screw extruder is preferred over the single-screw extruder, and a lubricant, primary and secondary antioxidants, light stabilizers, colorants, fillers, reinforcing agents, impact modifiers and / or flame retardants are added to the extrusion kneading. Final molding raw materials can be provided. In addition, a surfactant (for example, Triton X-100) and a coupling agent may be added to increase the dispersion of the graphene nanoplatelet and the interaction with the polymer.

The polymer nanocomposite composition is an antioxidant, a light stabilizer, a heat stabilizer, a reinforcing agent, an anti-slip agent, an antibiotic (biocides), a colorant, a flame retardant, a surfactant, a coupling agent, an impact modifier, a fiber reinforcing agent (glass fiber, carbon fiber, etc.) ) and at least one selected from the group consisting of antiwear agents.

Hereinafter, the present invention will be described in more detail by way of examples. However, this is for illustrative purposes and the scope of the present invention is not limited thereby.

[Example]

Example 1: Graphene nanoplatelets

40 g of expanded graphite ES 20 C200 (Qingdao Kropfmuehl Graphite Co.) was heat-treated in an electric furnace at 600° C. for 30 minutes to obtain about 36 g. At this time, the apparent density was 0.033 g/cm ³ . Thereafter, the heat-treated expanded graphite was placed on a silicon plate, and a scanning electron micrograph at this time was shown in FIG. 1 . Subsequently, the heat-treated expanded graphite was pulverized with a silicon millstone device shown in FIG. 2 to obtain a pulverized expanded graphite powder having an apparent density of 0.21 g/cm ³ . 30 g of the pulverized expanded graphite powder thus obtained and 60 g of poly (ethylene glycol) having an average molecular weight (Mw) of 2000 were placed in a 250 ml beaker, heated to 150 ° C, and stirred at 150 rpm for 10 minutes with a stirrer to uniformly mix, and then a cylinder-shaped mold After cooling, a disc-shaped mixture with a diameter of 15 cm was obtained. The disk-shaped mixture was polished and pulverized with a grinder attached with 40 mesh sanding paper to obtain a fine mixture powder, and then heat-treated in an electric furnace at 600° C. for 30 minutes to prepare graphene nanoplatelets. Finally, the graphene nanoplatelets were pulverized in a ball mill and sieving with a 500 mesh was repeated to obtain graphene nanoplatelets having a diameter of 30 μm or less and a thickness of 8 nm. Scanning electron micrograph of the graphene nanoplatelets obtained at this time is shown in Figure 3.

[Polymer nanocomposite material]

Examples 2 to 4

LUPOY GN5001RF, a non-halogen flame retardant PC/ABS blend sold by LG Chem, graphene nanoplatelets prepared according to Example 1 were dry mixed in the proportions given in Table 1 below, and then antioxidants were added in the proportions given in Table 1 below. was added, and kneaded at 150 rpm at a maximum temperature of 270 ° C. with a twin screw extruder (Korea EM Co., Ltd., STS-25-40-2V model). At this time, the LUPOY GN5001RF was dried in a dryer at 80 ° C. for 4 hours, and the LUPOY GN5001RF contained 40 to 80 parts by weight of polycarbonate, 5 to 20 parts by weight of an acrylo-nitrile-styrene terpolymer, and bisphenol diphenyl phosphate as a flame retardant. 5 to 20 parts by weight. As the antioxidant, 0.2 parts by weight of Songnox 21B from Songwon, which is a 1:2 blend product of a primary antioxidant (Songnox 1010) and a secondary antioxidant (Songnox 1680), was added.

The strand extruded through the twin screw extruder is cooled in a cooling water bath, then pelletized with a pelletizer, dried in an oven dryer at 80 ° C for 24 hours, and an extruder (Daihan Electric Wire LDH-75N model) at a maximum temperature of 270 ° C Specimens were prepared and various physical properties were evaluated.

Examples 5 and 6

LUPOY GN5001RF, a non-halogen flame retardant PC/ABS blend sold by LG Chem, graphene nanoplatelets prepared according to Example 1 were dry mixed in the proportions given in Table 1 below, and then antioxidants were added in the proportions given in Table 1 below. was added, and a specimen was immediately prepared at a maximum temperature of 270 ° C using an injection molding machine (model LDH-75N of Taihan Electric Wire) to evaluate various physical properties. At this time, the LUPOY GN5001RF was dried in a dryer at 80 ° C for 4 hours, and the antioxidant was 0.2 Added by weight.

Comparative Example 1

After mixing LUPOY GN5001RF, a non-halogen flame retardant PC/ABS blend sold by LG Chem, and an antioxidant in the ratio given in Table 1 below, the maximum temperature of 270 It was kneaded at 150 rpm at °C. At this time, the LUPOY GN5001RF was dried in a dryer at 80 ° C for 4 hours, and the antioxidant was 0.2 Added by weight.

The strand extruded through the twin-screw extruder is cooled in a cooling water bath, then pelletized with a pelletizer, dried in an oven dryer at 80 ° C for 24 hours, and a specimen at a maximum temperature of 270 ° C with an extruder (model LDH-75N of Taihan Electric Wire) It was prepared and various physical properties were evaluated.

Comparative Example 2

LUPOY GN5001RF, a non-halogen flame retardant PC/ABS blend sold by LG Chem, and heat-treated expanded graphite powder were dry mixed in the proportions given in Table 1 below, then antioxidants were added in the proportions given in Table 1 below, and a twin-screw extruder (Korea) EM Co., Ltd., STS-25-40-2V model) was kneaded at 150 rpm at a maximum temperature of 270 ° C. At this time, the LUPOY GN5001RF was dried in a dryer at 80 ° C for 4 hours, and the antioxidant was 0.2 Added by weight. In addition, the heat-treated expanded graphite powder is a powder obtained by heat-treating 40 g of expanded graphite ES 20 C200 (Qingdao Kropfmuehl Graphite Co.) in an electric furnace at 600° C. for 30 minutes, and has an apparent density of 0.033 g/cm ³ .

The strand extruded through the twin-screw extruder is cooled in a cooling water bath, then pelletized with a pelletizer, dried in an oven dryer at 80 ° C for 24 hours, and a specimen at a maximum temperature of 270 ° C with an extruder (model LDH-75N of Taihan Electric Wire) It was prepared and various physical properties were evaluated.

Comparative Example 3

LUPOY GN5001RF, a non-halogen flame retardant PC/ABS blend sold by LG Chem, and heat-treated expanded graphite powder were dry mixed in the proportions given in Table 1 below, then antioxidants were added in the proportions given in Table 1 below, and immediately injected into the injection molding machine (for Wire LDH-75N model), specimens were prepared at a maximum temperature of 270 ° C, and various physical properties were evaluated. At this time, the LUPOY GN5001RF was dried in a dryer at 80 ° C for 4 hours, and the antioxidant was 0.2 Added by weight. In addition, the heat-treated expanded graphite powder is a powder obtained by heat-treating 40 g of expanded graphite ES 20 C200 (Qingdao Kropfmuehl Graphite Co.) in an electric furnace at 600° C. for 30 minutes, and has an apparent density of 0.033 g/cm ³ .

The composition of the non-halogen flame retardant PC/ABS nanocomposites of Examples 2 to 6 and Comparative Examples 1 to 3 prepared by the above method is shown in Table 1 below.

division Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 LUPOY GN5001RF 99.7 99.6 99.3 99.7 99.6 99.8 99.7 99.7 Example 1
(graphene nanoplatelets) 0.1 0.2 0.5 0.1 0.2 - - - heat treated expanded graphite - - - - - - 0.1 0.1 antioxidant
(Songnox 21B) 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2

[Test Example]

Test Example 1: Mechanical Characteristics Analysis

The physical properties of the polymer nanocomposites of Examples 2 to 6 and Comparative Examples 1 to 3 were measured in the following manner, and the results are shown in Table 2 below.

1) Tensile strength, tensile modulus and elongation: 3.2mm tensile specimen, ASTM D 638

2) Flexural strength and flexural modulus: 6.4mm bar specimen, ASTM D 790

3) Impact strength (Notched Izod): 3.2mm bar specimen, ASTM D 256

4) Flame retardancy: UL 94 vertical burning test on 5 bar specimens with a thickness of 1.6 mm

division Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Yield tensile strength (MPa) 61 60 60 59 61 60 58 59 Tensile Modulus (GPa) 2.3 2.4 2.5 2.2 2.3 2.1 2.2 2.2 Elongation (%) 43 40 35 44 39 45 42 43 Flexural strength (MPa) 88 91 98 87 89 83 85 84 Flexural modulus (GPa) 2.1 2.3 2.7 2.0 2.2 1.9 2.0 1.9 impact strength
(J/m) 401 405 413 397 400 395 390 395 flame retardant
(UL 94V) V0 V0 V0 V0 V0 V0 V0 V0

Referring to Table 2, the mechanical properties of the graphene nanoplatelet-reinforced non-halogen flame retardant PC/ABS nanocomposite according to the present invention showed overall improved results compared to pure non-halogen flame retardant PC/ABS (Comparative Example 1). However, the yield point tensile strength was almost constant, and the impact strength slightly increased. The mechanical properties of the extrusion-kneaded nanocomposites (Examples 2 to 4) were slightly better than those of the directly injected nanocomposites (Examples 5 and 6), indicating better dispersion of graphene nanoplatelets by extrusion-kneading. It is presumed to be because

In addition, in the case of Example 4 in which 0.5% by weight of graphene nanoplatelet was added, the tensile modulus increased by 19%, the flexural strength increased by 13%, and the flexural modulus increased by 42% compared to Comparative Example 1 without the addition. Compared to carbon nanotubes or carbon black, the graphene nanoplatelet has a greater effect on reinforcing mechanical properties, and in particular, it is determined that the bending properties and tensile modulus are significantly improved due to the plate shape. Therefore, when 2% by weight or more of the graphene nanoplatelet according to the present invention is added, the tensile and flexural moduli greatly increase, but the viscosity increases, making injection processing difficult. In particular, since it is very difficult to process a large-scale injection molding product weighing 1 kg or more, it is preferable to add a graphene nanoplatelet content as low as 1.5% by weight or less in order to improve mechanical properties while maintaining processability.

Test Example 2: SEM image analysis

2 is a scanning electron micrograph of expanded graphite used in any one embodiment of the present invention, and FIG. 3 is a silicon millstone device (left) used in any one embodiment of the present invention and through the silicon millstone device It is a photograph of pulverized expanded graphite, and FIG. 4 is a scanning electron micrograph of a graphene nanoplatelet according to the present invention.

According to FIGS. 2 to 4, the expanded graphite used in Example 1 is confirmed to be stacked with sheets divided into several tens of layers, and has a very low density, that is, an apparent density of 0.01 to 0.05 g / It was confirmed that it was distributed between cm ³ (FIG. 2). In addition, the apparent density increased as the layered structure was broken by the silicon milling device (FIG. 3), and finally, graphene nanoplatelets with a diameter of 30 μm or less and a thickness of 8 nm with a controlled particle size were confirmed.

In the above, the preferred embodiments of the present invention have been described, but those skilled in the art can add, change, delete or modify components within the scope not departing from the spirit of the present invention described in the claims. Various modifications and changes may be made to the present invention by addition or the like, which will also be included within the scope of the present invention. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form. The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be construed as being included in the scope of the present invention. do.

Claims (9)

A polymer compound containing at least one selected from the group consisting of thermoplastic polymers and thermosetting polymers; and
graphene nanoplatelets; second
A polymer nanocomposite material composition comprising: According to claim 1,
The polymer nanocomposite composition, characterized in that the polymer compound is a PC / ABS compound containing polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS). (a) preparing expanded graphite by heat-treating a first mixture including graphite;
(b) preparing a second mixture by mixing the expanded graphite and an organic binder; and
(c) preparing a graphene nanoplatelet by grinding the second mixture;
A method for producing a graphene nanoplatelet comprising: According to claim 3,
In step (a),
the first mixture comprises an acid substance;
Method for producing a graphene nanoplatelet, characterized in that the acid material comprises sulfuric acid or nitric acid. According to claim 3,
After step (a),
(a') grinding the expanded graphite to prepare expanded graphite having a high apparent density; According to claim 3,
In step (b),
The organic binder is sugar, oligosaccharide, malt, poly (ethylene glycol), methoxy poly (ethylene glycol), dimethoxy poly (ethylene glycol), poly (propylene glycol), methoxy poly (propylene glycol), dimethoxy poly ( Propylene glycol), poly(vinyl alcohol), poly(vinyl acetate), polyolefins, oxidized polyolefins, and waxes. According to claim 3,
step (c)
(c-1) preparing a pulverized mixture by pulverizing the second mixture;
(c-2) preparing a graphene nanoplatelet by removing the organic binder of the pulverized mixture. According to claim 3,
After step (c),
(d) adjusting the particle size of the graphene nanoplatelet to prepare a graphene nanoplatelet having a controlled particle size; (a) preparing a graphene nanoplatelet according to the manufacturing method of claim 3; and
(b) preparing a polymer nanocomposite material composition by mixing a polymer compound containing at least one selected from the group consisting of a thermosetting polymer and a thermoplastic polymer and the graphene nanoplatelet;
A method for producing a polymer nanocomposite material composition comprising: