KR20090050853A - Biodegradable polymer resin composition comprising carbon nanotube - Google Patents

Abstract

The present invention provides a biodegradable polymer resin composition comprising a biodegradable polymer resin and carbon nanotubes. By using the composition, it is possible to make a natural friendly product that has excellent electrical and mechanical properties and decomposes in a natural state after use.

Description

Biodegradable polymer resin composition comprising carbon nanotube

The present invention relates to a biodegradable polymer resin composition comprising carbon nanotubes, and more particularly to a composition in which carbon nanotubes are added to a biodegradable polymer resin, which is an environmentally friendly material, in the form of a filler. The present invention relates to an environmentally friendly functional resin composition which can be decomposed in a natural state after use.

Carbon Nanotube (CNT) is a nanomaterial in which a plate-like graphite sheet, in which carbon atoms are bonded in a hexagonal honeycomb pattern, is rolled in a tube shape of several nanometers to several hundred nanometers in diameter.

Carbon nanotubes exhibit unique electrical, mechanical, physical, and chemical properties due to their unique electronic structure and nanometer diameter. For example, it has a density of about 1/2 of aluminum, but is 100 times stronger than steel, and 1000 times higher than that of copper or silver. Due to the excellent properties of these carbon nanotubes, industrial applications are being actively conducted in various fields such as field emission displays, memory, fuel cells, and sensors. In particular, a resin composite that forms a composite with a polymer resin to impart conductivity to the resin or improve mechanical strength is one of the largest application markets for carbon nanotubes. The polymer resin composite utilizes the excellent mechanical strength, electrical and thermal conductivity of carbon nanotubes, and can improve mechanical and electrical performance, such as strength, without deteriorating physical polymer properties.

As a method of preparing a polymer resin composite, a method of mixing a carbon nanotube in a molten state by applying heat to a thermoplastic polymer, a method of mixing a resin with a carbon nanotube after dissolving the resin in a solvent, a mixture of a resin monomer and a carbon nanotube After the polymerization, there is a method of making a resin composite.

The carbon nanotube / polymer resin composition known to date is composed of a resin raw material that causes air pollution or soil pollution due to incineration or landfill upon disposal such as polycarbonate, polystyrene, nylon, and polyester. In addition, polymer resin composites such as automobile structures and electronic component cases are consumed and disposed in large quantities, and thus environmental pollution is a serious issue worldwide. Therefore, the industrial demand for biodegradable polymer resin that can be rapidly degraded in the natural state after use to minimize environmental pollution is increasing.

Therefore, the technical problem to be achieved by the present invention is to meet the above-mentioned needs, and through the composite composition of the biodegradable polymer resin and carbon nanotubes having excellent electrical and mechanical performance, a variety of structural agents, electrical and electronic component materials, bio applications The present invention is to provide a bio-degradable polymer composition containing a natural carbon nanotube that can be applied to the application and biodegradable after use, and a plastic molded article using the same.

In order to achieve the above technical problem, the present invention provides a biodegradable polymer resin composition comprising a biodegradable polymer resin and carbon nanotubes.

Another technical problem of the present invention is to provide a plastic molded article formed from the biodegradable polymer resin composition described above.

Another technical problem of the present invention is a biodegradable polymer membrane; And a biodegradable antistatic sheet having a conductive coating film including carbon nanotubes and a binder on the biodegradable polymer film.

Another technical problem of the present invention is to coat and dry the above-described biodegradable polymer resin composition is made of a biodegradable antistatic sheet comprising a carbon nanotube, a biodegradable polymer resin and a binder.

The biodegradable polymer membrane may be a polylactide sheet or a film.

The biodegradable polymer resin composition of the present invention comprises a biodegradable polymer resin and carbon nanotubes.

The biodegradable polymer resin serves to cover the surface of the carbon nanotubes to suppress entanglement of carbon nanotubes and agglomeration between carbon nanotubes. The biodegradable polymer resin, which strongly surrounds the surface of the carbon nanotubes, makes it possible to disperse the carbon nanotubes in various solvents. When the film is manufactured using such a biodegradable polymer resin composition, bending of carbon nanotubes is suppressed and electrical properties are increased.

In addition, the addition of carbon nanotubes complements the mechanical durability of the biodegradable polymer resin, resulting in a strong external impact or high resistance to the external environment.

As the biodegradable polymer resin used in the present invention, polylactide (polylactide or polylactic acid), polycaprolactone, polyglycolide, prepared by using lactic acid (Lactic acid) produced by fermenting sugar extracted from grains such as corn, as a monomer And resins such as polyvalerolactone, polyhydroxy butyrate, polyhydroxy valerate, and copolymers thereof. These resin polymers have excellent properties like general polymer resins during use and are easily degraded by microorganisms in soil when disposed of after use.

The content of the carbon nanotubes in the biodegradable polymer resin composition is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the biodegradable polymer resin. If the content of carbon nanotubes is less than 0.01 parts by weight, the effect of adding carbon nanotubes is insignificant, and if it exceeds 10 parts by weight, the mechanical properties of the film made using the composition are deteriorated, which is not preferable.

The biodegradable polymer resin composition of the present invention may further include an additive suitable for the purpose in addition to the above-described components. For example, the additive may include at least one selected from the group consisting of reinforcing materials, binders, lubricants, mold release agents, plasticizers, nucleating agents, stabilizers, flame retardants, pigments, dyes, and inorganic additives.

The total content of the additive used in the present invention is preferably 0.01 to 30 parts by weight based on 100 parts by weight of the biodegradable polymer resin.

Examples of the reinforcing material include core-shell graft copolymers, silicone polymers, olefin polymers, and mixtures thereof. Specific examples thereof include ethyl acrylate-butadiene-styrene copolymers.

As said binder, an acryl- urethane copolymer, a vinyl copolymer, a modified acryl-type, an acryl-type copolymer, etc. are mentioned.

The lubricants, mold release agents, plasticizers, nucleating agents, stabilizers, flame retardants, pigments, dyes and inorganic additives can be used as long as they are all commonly used compounds.

Looking at the manufacturing method of the biodegradable polymer resin composition according to the present invention.

According to a first manufacturing method, a biodegradable polymer resin-forming monomer and carbon nanotubes are mixed, and then, a catalyst is added thereto, followed by a polymerization process of dehydrating and mixing the same in a polymerization tank. A biodegradable polymer resin composition can be obtained.

The biodegradable monomers may be used without any particular limitation as long as they are monomers capable of forming a biodegradable polymer resin. As an example of a biodegradable monomer, it is preferable to use lactic acid which is a monomer of polylactide.

The content of the carbon nanotubes is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the monomer for forming a biodegradable polymer resin.

The catalyst used for the polymerization reaction can be used without particular limitation as long as it is a catalyst used for dehydration polycondensation. For example, it is preferable to mix ruthenium oxide and titanium oxide in 1: 1 weight ratio.

The content of the catalyst is preferably 1 to 10 parts by weight based on 100 parts by weight of the monomer for forming a biodegradable polymer resin. And polymerization temperature changes with kinds of monomers for biodegradable resin formation, etc., and 110-160 degreeC is preferable.

According to the second manufacturing method, a biodegradable polymer resin composition may be prepared by applying heat to the biodegradable polymer resin and mixing the carbon nanotubes in a molten state. According to this method, a solvent is unnecessary because the biodegradable polymer resin and the carbon nanotube are mixed in the molten state. The content of carbon nanotubes is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the biodegradable polymer.

According to a third manufacturing method, a biodegradable polymer resin composition may be prepared by dissolving a biodegradable polymer resin in a solvent and then mixing carbon nanotubes. As the solvent, water and / or an organic solvent is used.

As the organic solvent, ethanol, dimethyl sulfoxide, a mixture thereof, and the like may be used, and the total content of the organic solvent is 10 to 30 parts by weight based on 100 parts by weight of the biodegradable polymer resin.

The biodegradable polymer resin composition obtained according to the present invention can be produced in a plastic molded article through a conventional method such as melt extrusion in an extruder.

According to one embodiment of the present invention, the biodegradable composition may be used as a coating composition applicable to biodegradable or conventional films, sheets, and the like.

Looking at the biodegradable antistatic sheet using the biodegradable polymer resin composition according to another embodiment of the present invention, as follows.

In order to obtain a biodegradable antistatic sheet according to an embodiment of the present invention, first, a biodegradable polymer resin is dissolved in water or an organic solvent, and carbon nanotubes are mixed therewith to obtain a biodegradable polymer resin composition.

The biodegradable polymer resin composition may include 20 to 80 parts by weight of water or an organic solvent, 10 to 60 parts by weight of a biodegradable polymer resin, 0.01 to 10 parts by weight of carbon nanotubes, 30 parts by weight of a binder, and particularly 0.01 to 30 parts by weight. desirable.

As the binder, an acryl-urethane compound or the like is used.

The composition may be melted and extruded to make pellets, and a film or a sheet may be used to prepare an antistatic sheet.

The antistatic sheet prepared according to the above process includes carbon nanotubes, a biodegradable polymer resin, and a binder.

Biodegradable antistatic sheet according to another embodiment of the present invention can be prepared according to the following method.

Coating and drying a conductive coating composition including carbon nanotubes, a solvent, and a binder on the biodegradable resin film to form a conductive coating film on the biodegradable resin film to complete a large front sheet. The antistatic sheet thus formed is a biodegradable polymer membrane; And a conductive coating film including carbon nanotubes and a binder on the biodegradable polymer film.

The coating method of the conductive coating composition is not particularly limited, but gravure coating, spin coating, or the like may be used. The biodegradable polymer resin film is not particularly limited, but may have a sheet or film form.

The thickness of the biodegradable resin film or sheet is not particularly limited, but is preferably about 0.02 to 10 mm.

 The conductive coating composition preferably comprises 20 to 90 parts by weight of water or an organic solvent, 0.01 to 10 parts by weight of carbon nanotubes, and 10 to 50 parts by weight of a binder.

The carbon nanotubes may be classified into single-walled carbon nanotubes (SWNT), double-walled carbon nanotubes (DWNT), or multi-walled carbon nanotubes (MWNT) according to the number of walls constituting the same. The composition may include without limitation carbon nanotubes of all of them.

The carbon nanotubes are electro-discharge, thermal chemical vapor deposition, pyrolysis, laser vaporization, plasma enhanced chemical vapor deposition, electrical Although it can synthesize | combine using a decomposition method or a flame synthesis method, etc., the carbon nanotube synthesize | combined by arbitrary methods is not limited to this synthesis method, It can be included in the said resin composition without a restriction | limiting.

According to the present invention, it is possible to obtain an environmentally friendly resin composition by decomposing in a natural state after use while showing excellent electrical conductivity, thermal stability, and mechanical properties by the carbon nanotube properties used as a filler. In addition, the biodegradable polymer resin wraps the surface of the carbon nanotubes, thereby suppressing the bending of the carbon nanotubes, so that the electrical flow between the carbon nanotubes can easily occur. Therefore, a small amount of carbon nanotubes can be used to realize various electrical characteristics. Can be. Carbon nanotubes, which are used as fillers in biodegradable polymer resin layers, are difficult to mix with general polymer compounds, so they can be mixed and dispersed with the help of various dispersants and additives. It is possible to minimize the electrical characteristics of the carbon nanotubes are reduced. The binding force between the carbon nanotube and the biodegradable polymer is maximized by Π-Π interaction when the molecular structure of the biodegradable polymer resin is similar to that of the carbon nanotube, and the length of the biodegradable polymer resin corresponds to the length of the carbon nanotube. Is ideal.

Carbon nanotubes combined with biodegradable polymers have a hard stick shape. Therefore, such biodegradable polymer resins can be used for antistatic and electrostatic discharge by imparting conductivity to various electrical devices, housings or electronic assemblies or cables, and can be used for various purposes, such as mechanical structures such as automobiles, biocompatible materials, and drug delivery systems. It can be used preferably.

Hereinafter, the present invention will be described with reference to the following examples, but does not mean that the present invention is limited only to the following examples.

 Example 1

In a mixing and dispersing apparatus, 99 parts by weight of lactic acid and 1 part by weight of multi-walled carbon nanotubes synthesized by thermochemical vapor deposition were mixed and uniformly dispersed.

Biodegradable polymer resin containing carbon nanotubes and polylactide was mixed with 3 parts by weight of ruthenium oxide and titanium oxide in a weight ratio of 1 part by weight of a polymerization catalyst, followed by dehydration condensation polymerization in a 130 ° C. polymerization tank. The composition was prepared.

A film was prepared using the biodegradable polymer resin composition obtained according to Example 1, and the film was examined using an electrophotographic microscope.

1 is an electron micrograph of a film obtained according to Example 1. FIG.

Referring to this, electron micrographs of carbon nanotubes dispersed in a polylactide, which is a biodegradable polymer resin, form a film, and the polylactide polymer is surrounded on the surface of the carbon nanotubes to maintain a thinner rod shape. The thin rod shows that the self-aggregation of carbon nanotubes is suppressed by the polylactide polymer, which shows excellent permeability and electrical conductivity even with the addition of a small amount of carbon nanotubes.

Example 2

A biodegradable polylactide composition was prepared by mixing 98 parts by weight of polylactide, 1 part by weight of multi-walled carbon nanotubes synthesized by vapor deposition, and 1 part by weight of ethyl acrylate-butadiene-styrene copolymer as a reinforcing material. The composition was melt extruded in an extruder to prepare pellets.

The pellet was used to inject in a 10 oz injection machine to prepare 10 cm × 10 cm specimens for measuring various physical properties and electrical conductivity. The surface resistance of the specimen showed 1 × 10 ⁷ ohms / sq as measured by ASTM D257. As such, the electrical conductivity of the specimen was excellent.

Example 3

A biodegradable polymer resin coating composition was prepared by mixing 60 parts by weight of a mixed solvent of water, DMSO and ethanol, 0.5 parts by weight of multi-walled carbon nanotubes synthesized by vapor deposition, and 39.5 parts by weight of polylactide.

The coating composition was coated on a polylactide sheet using a gravure coating method and thermally cured to prepare a biodegradable antistatic sheet.

Example 4

A conductive coating composition was prepared by mixing 60 parts by weight of a mixed solvent of water, DMSO and ethanol, 0.5 parts by weight of multi-walled carbon nanotubes synthesized by vapor deposition, 38.5 parts by weight of an acryl-urethane binder, and 1 part by weight of a crosslinking agent.

The conductive coating composition was coated on a polylactide sheet using a gravure coating method and thermally cured to prepare a biodegradable antistatic sheet.

Comparative Example 1

The biodegradable polymer resin composition was carried out in the same manner as in Example 1 except for adding poly (3,4-ethylenethiophene), which is a water-soluble conductive polymer, in place of carbon nanotubes.

The antistatic composition prepared according to the above method was coated on a polylactide sheet using a gravure coating method and then thermally cured at 50 ° C. for 10 minutes to prepare an antistatic sheet. Here, the surface resistance of the antistatic sheet is measured by the ASTM D257 method.

The physical property test results of the biodegradable antistatic sheet prepared in Examples 1-4 and Comparative Example 1 are shown in Table 1 below.

TABLE 1

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Surface resistance (ohm / square) 5 x 10 ⁷ 1 x 10 ⁷ 5 x 10 ⁶ 2 x 10 ⁷ 3 x ^{10 9} Transparency (%) 93 93 91 92 92 Haze (%) 0.7 0.5 0.8 0.5 0.7

In addition, the impact resistance and electrical conductivity of the sheets prepared according to Examples 3 and 4 were evaluated.

As a result of the evaluation, it was confirmed that the electrical conductivity is excellent, but also the shock resistance is excellent antistatic function. Alternatively, the sheet contains biodegradable polymer resins, which are environmentally friendly since they can be decomposed in a natural state.

Figure 1 shows an electrophotographic micrograph in the film obtained according to Example 1 of the present invention.

Claims (10)

Biodegradable polymer resin composition comprising a biodegradable polymer resin and carbon nanotubes. The biodegradable polymer resin composition according to claim 1, wherein the content of the carbon nanotubes is 0.1 to 10 parts by weight based on 100 parts by weight of the biodegradable polymer. The method of claim 1, wherein the biodegradable polymer resin, A biodegradable polymer resin composition, characterized in that at least one selected from the group consisting of polylactide, polycaprolactone, polyglycolide, polyvalerolactone, polyhydroxy butyrate, polyhydroxy valerate, and copolymers thereof. The method of claim 1, wherein the carbon nanotubes, Biodegradable polymer resin composition comprising at least one selected from the group consisting of single-walled carbon nanotubes (SWNT), double-walled carbon nanotubes (DWNT) or multi-walled carbon nanotubes (MWNT). The biodegradable polymer resin composition of claim 1, further comprising at least one additive selected from the group consisting of reinforcing materials, binders, lubricants, mold release agents, plasticizers, nucleating agents, stabilizers, flame retardants, pigments, dyes, and inorganic additives. . Plastic molded article formed from the biodegradable polymeric resin composition of any one of Claims 1-5. Biodegradable polymer membranes; And a conductive coating film comprising carbon nanotubes and a binder on the biodegradable polymer film. The biodegradable antistatic sheet according to claim 7, wherein the biodegradable polymer membrane is a polylactide sheet or a film. A biodegradable antistatic sheet comprising a carbon nanotube, a biodegradable polymer resin and a binder by coating and drying the biodegradable polymer resin composition according to any one of claims 1 to 5. The biodegradable antistatic sheet according to claim 9, wherein the biodegradable polymer membrane is a polylactide sheet or a film.

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