KR20190083926A - Method for fabricating composite sheets of films and fibers using polymer microspheres containing carbon nanomaterials, and composite sheets of films and fibers therefrom - Google Patents

Abstract

The present invention relates to a method for manufacturing a film/fiber composite sheet by manufacturing spherical polyvinyl acetate fine particles containing carbon nanomaterials mixed by suspension polymerization, manufacturing nanocomposite fine particles of spherical carbon nanomaterials/polyvinyl alcohol in which carbon nanomaterials are dispersed by heterogeneous saponification of spherical polyvinyl acetate mixed with the carbon nanomaterials, manufacturing a second polymer film in which carbon nanomaterials are uniformly dispersed by melt pressing, and manufacturing a film/fiber composite sheet using the second polymer film. The film/sheet type composite sheet of the present invention has excellent mechanical strength, excellent electrical/thermal conductivity, as well as excellent fracture strength when incorporated into a building material.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a film / fiber composite sheet using polymeric microparticles containing carbon nanomaterials and a film / and fibers therefrom}

The present invention relates to a method for producing a film / fiber composite sheet using polymeric microparticles containing carbon nanomaterials and a film / fiber composite sheet produced thereby, and more particularly, The first polymer nanocomposite film is dispersed in a polymer capable of being melted (hereinafter, referred to as a first polymer) and melt-pressed to prepare a first polymer nanocomposite film having uniformly dispersed carbon nanomaterials. A composite sheet, a method of producing a film / fiber composite sheet, and a film / fiber composite sheet produced thereby.

Thermosetting polymer composite materials are mainly used in fields requiring high strength such as aircraft parts and racing car parts and sports fields such as golf clubs, fishing rods, badminton rackets, and bicycle frames. However, thermosetting polymer composites have limitations in molding time, recycling problems, and technological limitations in mass production, thus limiting their application to various fields. It is a thermoplastic polymer composite material that can overcome these drawbacks and has advantages that conventional thermosetting polymer composite materials have, such as repeated thermoforming, short molding cycle, mass production, VOC free, and recycling. Therefore, based on these advantages, it is expected that application areas of thermoplastic composite materials will be rapidly expanded by replacing metal parts with lightweight automobiles. However, thermoplastic resins generally have a high melt viscosity. Particularly, a polymer resin having a high heat resistance and mechanical strength has a high molecular weight and a high melt viscosity, so that the resin is not uniformly impregnated upon impregnation, And it is difficult to manufacture the surface smoothly. Attempts have been made to impregnate carbon nano materials of carbon nanotubes (CNTs, hereinafter referred to as CNTs) into resins for the purpose of improving the impregnation of fibrous resin and improving heat resistance.

The carbon material is a polycrystalline material in which a carbon hexahedron is a layered crystallizer. Examples thereof include a graphite material, graphene, graphite, carbon nanotube (CNT), and the like. In particular, carbon nanotubes (CNTs) have a variety of structures in which the graphite sheet has a rounded shape with a nanometer-scale diameter and has different characteristics depending on the angle and shape of the graphite surface. It has excellent electrical properties, excellent properties as a thermal conductor, high aspect ratio of 1000 or more, electrical and thermal conductivity, low density, flexibility. Therefore, polymer composites with carbon nanotubes added have high strength and low weight properties. Carbon nanotubes can also be used to impart electrical conductivity to nonconductive polymers. However, in order to improve the intrinsic properties of the polymer by combining the carbon nanotubes with the polymer, the carbon nanotubes must be well dispersed in the polymer, and strong interfacial adhesion between the polymer matrix and the carbon nanotubes must exist.

Polyvinyl alcohol (PVA) is a semi-crystalline synthetic polymer having a hydroxy group capable of forming a hydrogen bond. It can not be synthesized by direct polymerization of vinyl alcohol monomers. Polyvinyl acetate (PVAc ) And synthesizing them by hydrolysis with an alkali or an acid. Polyvinyl acetate and polyvinyl alcohol differ in the types of solvents that can be dissolved. Specifically, polyvinyl acetate is dissolved in methanol, ethanol, tetrahydrofuran (THF), dimethylsulfoxide (DMSO), benzene, acetone, ethyl acetate, methylene chloride, methyl ethyl ketone, toluene, ethylene glycol, diacetate It is difficult to dissolve in water. On the other hand, polyvinyl alcohol is soluble in water but hardly soluble in organic solvents.

Polyvinyl alcohol has excellent compatibility with blend and is widely used for various purposes such as medical materials, packaging materials, release films, water-soluble films, and polarizing films. However, since polyvinyl alcohol is not dissolved in an organic solvent, it is difficult to apply in a field where molding such as a film is required.

Accordingly, there is a demand for a method for producing a polyvinyl alcohol film in which carbon nanomaterials are uniformly dispersed in order to improve electrical / thermal conductivity, mechanical properties, and the like.

Examples of the meltable polymer include polyethylene (LDPE, HDPE), polypropylene, polyisobutylene, polyamide (nylon 6, nylon 66), polyester, and polystyrene acetal. It is difficult to disperse nanoparticles due to agglomeration phenomenon.

Korean Patent No. 10-1040728

The present invention relates to a first polymer film using polyvinyl alcohol particles having uniformly dispersed carbon nanomaterials improved in electric / thermal conductivity, mechanical properties, etc., a method for producing a composite sheet comprising the same, and a composite sheet produced thereby .

A first aspect of the present invention relates to a water phase comprising a carbon nanomaterial; And a vinyl acetate-based monomer, thereby producing spherical poly (vinyl acetate) microparticles incorporating the carbon nanomaterial;

A second step of producing nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol dispersed in a carbon nanomaterial by non-uniformly saponifying spherical polyvinyl acetate mixed with the carbon nanomaterial; And

And a third step of dispersing the nanocomposite fine particles of the carbon nanomaterial / polyvinyl alcohol thus prepared in a molten first polymer and melt-pressing the nanocomposite fine particles to prepare a first polymer film in which the carbon nanomaterial is dispersed.

A method for producing a polymer film in which carbon nanomaterials are dispersed is provided.

A second aspect of the present invention relates to a water phase comprising a carbon nanomaterial; And a vinyl acetate-based monomer, thereby producing spherical poly (vinyl acetate) microparticles incorporating the carbon nanomaterial;

A second step of producing nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol dispersed in a carbon nanomaterial by non-uniformly saponifying spherical polyvinyl acetate mixed with the carbon nanomaterial;

A third step of dispersing the nanocomposite particles of the carbon nanomaterial / polyvinyl alcohol produced in the above-mentioned first polymer in a molten state and melt-pressing them to produce a polymer film in which the carbon nanomaterial is dispersed; And

And spinning the second polymer spinning solution on the film to form a second polymer fiber layer.

The present invention provides a method for producing a composite sheet comprising a first polymer film and a second polymer fiber layer in which carbon nanomaterials are dispersed.

A third aspect of the present invention relates to a water phase comprising a carbon nanomaterial; And a vinyl acetate-based monomer, thereby producing spherical poly (vinyl acetate) microparticles incorporating the carbon nanomaterial;

A second step of producing nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol dispersed in a carbon nanomaterial by non-uniformly saponifying spherical polyvinyl acetate mixed with the carbon nanomaterial; And

The third polymeric film in which the carbon nanomaterial is dispersed by melt-pressing the carbon nanomaterial / polyvinyl alcohol nanocomposite particles and the first polymer on the fiber layer formed by spinning the second polymer spinning solution, ≪ / RTI >

The present invention provides a method for producing a composite sheet comprising a first polymer film and a second polymer fiber layer in which carbon nanomaterials are dispersed.

A fourth aspect of the present invention provides a method for producing a carbon nanostructure, comprising: a first polymeric film layer in which a carbon nanomaterial is dispersed; And a second polymer fiber layer formed on the film layer,

[0030] The production method of the second aspect of the present invention,

A composite sheet comprising a first polymer film having a carbon nanomaterial dispersed therein and a second polymer fiber layer.

In a fifth aspect of the present invention, the second polymeric fibrous layer includes a first polymeric film layer in which a carbon nanomaterial is dispersed,

[0030] The production method of the third aspect of the present invention,

A composite sheet comprising a first polymer film having a carbon nanomaterial dispersed therein and a second polymer fiber layer.

Hereinafter, the present invention will be described in detail.

The term "nano," as used herein, refers to nanoscale and may include microunits. Thus, the nanofiber layer or nanocapsule may have a size in nanoseconds or micrometers.

The carbon nanomaterial may be one selected from the group consisting of carbon nanotubes, graphite, graphene and graphite, preferably carbon nanotubes.

When the carbon nanomaterial is added to the polymer, the carbon nanomaterials tend to aggregate with each other, and thus the uniform dispersion is not achieved. Therefore, the adhesion between the polymer (first polymer) and the interface between the carbon nanomaterial is weak, The stress can not be sufficiently transferred to the carbon nanomaterial, resulting in poor performance. As a result of intensive efforts to solve these problems, the present inventors have found that polyvinyl acetate microparticles incorporating a carbon nanomaterial are produced without using a carbon nanomaterial and a polymer, respectively, and then dispersed in a molten polymer and melt- It was confirmed that a polymer film with well dispersed nanomaterial can be produced. Specifically, an aqueous phase containing a carbon nanomaterial; And a vinyl acetate-based monomer are stirred and subjected to suspension polymerization to produce spherical poly (vinyl acetate) microparticles incorporating carbon nanomaterials, followed by nonuniform saponification to obtain carbon nanomaterials having uniformly dispersed carbon nanomaterials / Polyvinyl alcohol nanocomposite fine particles were prepared. In this case, the carbon nanomaterial is uniformly dispersed in the polyvinyl alcohol, and nanocomposite particles having strong adhesion between the interface between the polyvinyl alcohol and the carbon nanomaterial can be produced. In addition to the first polymer capable of melting the nanocomposite particles, It was confirmed that a first polymer film in which carbon nanomaterials are uniformly dispersed can be produced by melting and pressing at a temperature.

Further, by forming the polymer fiber layer on the first polymer film or in the film, a composite sheet comprising a polyvinyl alcohol film and a polymer fiber layer in which carbon nanomaterials are uniformly dispersed can be produced. In this case, Can be prepared. The present invention is based on this.

The present invention relates to nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol for producing a polymer film in which carbon nanomaterials are uniformly dispersed.

The nanocomposite particles of the carbon nanomaterial / polyvinyl alcohol can be prepared by preparing a spherical poly (vinyl acetate) microparticle in which a carbon nanomaterial is incorporated by suspending a carbon nanomaterial with a vinyl acetic acid monomer, followed by heterogeneous saponification .

The present invention utilizes the suspension polymerization method for the production of nanocomposite particles of carbon nanomaterial / polyvinyl alcohol.

The suspension polymerization is carried out in the emulsion itself, which is formed by stirring an aqueous phase in which stabilizer is dissolved and an organic phase of a polyvinyl acetate monomer including carbon nanomaterials, a crosslinking agent and an initiator, and the polymer containing carbon nanomaterial .

The stabilizer may be various kinds of polymers such as polyvinyl alcohol or polyvinylpyrrolidone as a suspending agent to prevent aggregation of the dispersed emulsion. As the initiator, 2,2-azobisisobutyronitrile can be used. A crosslinking agent, divinylbenzene, may be used for the crosslinking reaction.

The present invention converts non-uniformly saponified spherical poly (vinyl acetate) particles mixed with carbon nanomaterials into nanocomposite particles of carbon nanomaterial / polyvinyl alcohol.

Polyvinyl alcohol can not be synthesized by direct polymerization of a vinyl alcohol monomer, and a method of synthesizing polyvinyl acetate (PVAc) using a vinyl acetate-based monomer and hydrolyzing them with an alkali or an acid, that is, can do.

The heterogeneous saponification may be performed by impregnating polyvinyl acetate / carbon nanotube nanocomposite fine particles into a mixed solution which is an acid or an alkali solution containing a dispersant and a swelling agent. The dispersing agent may be at least one selected from the group consisting of sodium sulfate, sodium sulfite, calcium sulfate and magnesium sulfate. The swelling agent may be at least one selected from the group consisting of methanol, ethanol, propanol, ethylene glycol, propylene glycol, tetrahydrofuran (THF), dimethylsulfoxide (DMSO), benzene and acetone. The saponification may be carried out at a temperature range of 5 [deg.] C to 70 [deg.] C for 2 hours to 100 hours.

The content of the carbon nanomaterial in the nanocomposite particulates of the carbon nanomaterial / polyvinyl alcohol is preferably 0.01 to 30% by weight based on the weight of the vinyl acetate monomer. When the content of the carbon nanomaterial is less than 0.01% by weight, the mechanical properties and electric / thermal conductivity enhancement effects due to the addition of the carbon nanomaterial may be insufficient. When the content of the carbon nanomaterial is greater than 30% by weight, It is impossible to improve the mechanical properties such as the tensile elastic modulus and the tensile strength value.

The nanocomposite particles of the carbon nanomaterial / polyvinyl alcohol may further include functional inorganic nanoparticles.

The functional inorganic nanoparticles may be selected from the group consisting of metal nanoparticles, nanowires, oxide nanoparticles, porous nanomaterials, quantum dots and aerosols.

The metal nanoparticles may be selected from the group consisting of Ag, Au, clay, TiO ₂ , SiO ₂ , ZnO, Nano-diamond, Fe ₃ O ₄ and Fullerene. It is not limited.

The nanowire may be a silver nano wire or may be formed in a linear, plate or net type.

The oxide nanoparticles may be SnO ₂ , TiO ₂ , ZnO, VO ₂ , In ₂ O ₃ , NiO, MoO ₃ , SrTiO ₃ , Fe doped SrTiO ₃ , Fe ₂ O ₃ , WO ₃ or CuO nanoparticles. have.

The porous nanomaterial may be selected from the group consisting of zeolites, aluminosilicates, AlPOs, SAPOs, silicates, metal phosphates, Zeolitic Materials (Pillared Layered Materials, Metalphosphates, Nitrides, Sulfates), Hybrid Materials (Coordination Polymers coordination polymer, hybrid metal oxides).

The particle size of the nanocomposite particles of the carbon nanomaterial / polyvinyl alcohol may be 300 nm to 200 m. In one embodiment of the present invention, the shape of the polymer microparticles of the carbon nanomaterial / polyvinyl alcohol is confirmed by a microscope, and as a result, a polyvinyl alcohol polymer mixed with a carbon nanomaterial can be produced.

The present invention relates to a process for producing a polymer film in which a carbon nanomaterial is dispersed by melt-pressing a carbon nanomaterial / polyvinyl alcohol nanocomposite particulate on a first polymer.

It is difficult to uniformly disperse the carbon nanomaterial in the polymer, making it difficult to produce a polymer film having excellent adhesion between the polymer and the carbon nanomaterial interface. Further, in the case of the molten polymer, it is difficult to disperse the nano-inorganic particles, and thus it is difficult to form the nano-composite film. Accordingly, the present inventors have produced nanocomposite particles of polyvinyl alcohol / carbon nanomaterial and then melt-pressed them by a method such as extrusion molding to produce a polymer film in which carbon nanomaterials are dispersed.

Specifically, a film can be produced by melting and bonding the one or more carbon nanomaterials / polyvinyl alcohol nanocomposite particles and the polymer produced above. In this case, there is an effect that the carbon nanomaterial is uniformly dispersed in the film, and the film has an excellent mechanical strength.

The first polymer is selected from the group consisting of LDPE, L-LDPE, HDPE, PE, UHMWPE, PVA-PE, PMMA / PE, PA / PE, PA6 / PE, PE / EVOH, EHA / PE, TiO ₂ / PE, PVA, PVDF / PVA, PVC-g-PSSA, PVC-ZnO, PP / MWCNT / ZnO, PBS / PEO, PE / EAA / PE, CaCO ₃ / PE, TiO ₂ / PVA, PP, Chitosan / Y203 / PP, PP-PA, PP / PC, PE / PP, PS / HIPS, PS / PAAm, PS / P (S-EA), PS / TiO 2, PS / PEO, PS / PMMA, But are not limited to, PS-b-PAA, LDPE / PVDC, LDPE / EVA, EVA / PLA, PE / EVOH, PMMA / PE, PPS, PTFE, POM, PAN, PEN and PPO.

Extrusion molding refers to a processing method in which a resin is put into a hopper, the resin is fused and pressed by screw rotation to form a molded article of certain shape by pushing it toward the die, and then cooled and solidified to form a continuous product.

In one embodiment of the present invention, the nanocomposite particulate powder of the carbon nanomaterial / polyvinyl alcohol and the polymer resin are fed to an extruder and extruded while being melted to form a polyvinyl alcohol film in which the carbon nanomaterial is dispersed.

At this time, the temperature of the extruder varies depending on the polymer. However, when the first polymer is polyethylene, the extrusion speed is preferably 100 to 150 rpm, and the film winding speed of the extrusion molding machine is preferably 5 to 10 m / min.

The fibrous layer can be formed by spinning of the polymer (second polymer) spinning solution. In this case, the spinning may be centrifugal spinning or electrospinning, and a polymer jet is formed by centrifugal force or electric force. The spinning speed of the disk, the concentration of the polymer solution, the distance between the needle and the collector, The fiber layer can be manufactured by controlling the supply speed of the voltage and the like.

The polymer used for the spinning may be at least one polymer selected from the group including all the polymers used for solution spinning and all the polymers used for melt spinning.

 Specific examples of the polymer include polyesters, polyvinyl acetates, polyvinyl alcohols, polycarbonates, polystyrenes, polymethyl methacrylates, polyvinyl chlorides, polypropylenes, polyacrylonitriles, derivatives or copolymers thereof, and blend polymers thereof Lt; / RTI >

In addition, the polymer used for spinning may be at least one polymer selected from the group consisting of all the polymers used for solution spinning and all the polymers used for melt spinning, in addition to the polymer microparticles incorporating the functional inorganic nanoparticles, Or two or more polymeric polymers, or copolymers.

The concentration of the polymer in the spinning solution may be from 1% to 30% by weight as a factor related to the viscosity of the spinning solution. If the concentration of the polymer is less than 1% by weight, the solution becomes too thin to spray the solution, and it is not easy to form a nanofiber nonwoven fabric even if it is sprayed. When the amount is more than 30% by weight, it may be difficult to form a nanofiber nonwoven fabric due to a high viscosity.

The solvent contained in the spinning solution is selected from the group consisting of dimethyl acetamide (DMA), N, N-dimethylformamide, N-methylpyrrolidinone, DMSO, THF, (ethylene carbonate), DEC (diethyl carbonate), DMC (dimethyl carbonate), ethyl methyl carbonate (ECM), propylene carbonate, water, acetic acid, methanol, ethanol and acetone ≪ RTI ID = 0.0 > and / or < / RTI >

When electrospinning is used, a random type of fibrous nonwoven fabric is formed. When centrifugal spinning is used, an aligned type of fibrous nonwoven fabric can be formed.

When centrifugal radiation is used, the fibrous layer formed may comprise at least one shape selected from the group consisting of microfibers, nanofibers, nanoparticles, and microparticles produced according to process parameters of centrifugal spinning.

Fiber shapes and nanocapsules can be produced according to the centrifugal spinning speed of the disk and the concentration of the polymer. As the disc is rotated, the polymer solution moves away from the rotary shaft due to the centrifugal force to form a jet, and the polymer jet is stretched by the centrifugal force generated by the rotational force to be radiated in a fibrous form. When the concentration of the polymer solution is more than 30% by weight, the polymer chains in the solution are long and the number of chains is large, so that the entanglement phenomena between the polymers are increased, so that the polymer overcomes the surface tension and remains as a long continuous fiber. However, when the concentration of the polymer solution is 1 wt%, the entanglement of the polymer chain is reduced, and even if the centrifugal spinning is performed due to the surface tension, the round shape is maintained and thus remains as nanocapsules. In particular, as the rotational speed of the disk increases due to the strong rotational force, the orientation of the fibers becomes active to produce the aligned nanofibers. As the speed increases, the drawing force increases and the fiber diameter tends to decrease.

The fibrous layer may further include carbon nanomaterials and functional inorganic nanoparticles as needed.

An adhesive layer may be formed between the film layer and the fiber layer to enhance adhesion between the film layer and the fiber layer produced by processing the polymer fine particle powder containing the carbon nanomaterial and the functional nano inorganic particles.

As the adhesive, epoxy, urethane or the like can be used, but it is not limited thereto.

In an embodiment of the present invention, as shown in FIG. 3, a film is produced by melt-pressing a carbon nanomaterial-containing polymer, the film is placed in a collector, centrifugal spinning is performed to produce a film / Respectively.

In another embodiment of the present invention, as shown in FIG. 4, the carbon nanomaterial-containing polymer is pressed onto oriented nanofibers and microfibers produced by centrifugal spinning to produce a film / fiber composite sheet.

In still another embodiment of the present invention, a polyvinyl alcohol may be used in place of the polyvinyl alcohol such as polyester, polyvinyl acetate, polyvinyl alcohol, polycarbonate, polystyrene, polymethyl methacrylate, polyvinyl chloride, polypropylene, polyacrylonitrile, Or a copolymer thereof, and a blend polymer thereof may be used.

As shown in FIGS. 1 and 2, the composite sheet according to one embodiment of the present invention is composed of a polymer film layer containing a carbon nanomaterial and a polymer fiber layer. The polymeric film layer and the fibrous layer may further comprise other components as required. As shown in Fig. 1, the structure of the composite sheet may vary depending on the order of producing the film layer and the fibrous layer, the fibrous layer may be laminated on the film layer, and the fibrous layer may include the film layer.

The composite sheet comprising the carbon nanomaterial-dispersed polymer film and the polymer fiber produced according to the present invention has excellent mechanical strength, excellent electrical / thermal conductivity, and has excellent fracture strength Lt; / RTI > In addition, it is expected that the polymer film / fiber composite sheet in which the carbon nanomaterial of the present invention is dispersed can be used as a composite material requiring high performance such as automobile fender and cement reinforcing material.

1 and 2 are schematic exploded schematic views of a film / fiber composite sheet according to an embodiment of the present invention.
Fig. 3 is a schematic flow chart of a method of producing the film / fiber composite sheet of Fig. 1;
Fig. 4 is a schematic flow chart of a method of producing the film / fiber composite sheet of Fig. 2;
Fig. 5 is a schematic view of a centrifugal spinning device used in producing a fibrous layer contained in the film / fiber composite sheet of Fig. 1;
6 is a diagram schematically showing a state before and after polymerization of fine polymer particles containing a carbon nanomaterial used for producing a film layer included in the film / fiber composite sheet of FIG.
FIG. 7 is a view schematically showing a method of producing a film layer included in the film / fiber composite sheet of FIG. 1 using a polymeric fine particle containing a carbon nanomaterial by a melt extrusion method.
8 is a photomicrograph of the polymer fine particles containing the carbon nanomaterial produced according to the manufacturing method of FIG.
FIG. 9 is a microphotograph of a carbon nanomaterial-incorporated film / fiber composite sheet produced according to the manufacturing method of FIG.
FIG. 10 shows the mechanical properties of the carbon nanomaterial-incorporated film / fiber composite sheet and the carbon nanomaterial non-incorporated film / fiber composite sheet.

Hereinafter, the present invention will be described in more detail with reference to Examples. These embodiments are only for describing the present invention more specifically, and the scope of the present invention is not limited by these examples.

Manufacture of Film / Fiber Composite Sheet

First, polyvinyl acetate / CNT nanocomposite particles were prepared by suspending in order to prepare a film layer.

Specifically, 1 g of a benzene peroxide initiator was completely dissolved in 200 g of vinyl acetate as a monomer in a 1000 ml four-necked glass reactor equipped with a stirrer, 2 g of carbon nanotubes were added and dispersed by stirring at 500 rpm for 5 minutes. Then, 30 g of the monomer was added to the mixture, and the mixture was stirred at 300 rpm for 1 hour to completely dissolve the monomer mixture to prepare a monomer mixture. 30 g of a polyvinyl alcohol dispersion stabilizer solution dissolved in distilled water at a concentration of 10% was added to the reactor, and the monomer mixture was emulsified by sufficiently stirring at a speed of 500 rpm for 30 minutes at room temperature. 300 g of distilled water as a reaction solvent was added to a 2-liter four-necked glass jacket reactor equipped with a dispersion stirrer and a thermostat circulator, and then the emulsified monomer mixture was added at room temperature and stirred at 250 rpm.

After confirming that the monomer mixture was pulverized into small monomer droplets by the generation of shear force through the discharge of the emulsified stabilizer therein, the temperature of the reactor was raised to 80 캜 and suspension polymerization was carried out. The prepared polymer particles were washed with distilled water and methanol several times by using a centrifuge to remove unreacted materials and dispersion stabilizer.

Polyvinyl alcohol / CNT nanocomposite fine particles were prepared by applying a heterogeneous system saponification method to the polyvinyl acetate / CNT nanocomposite fine particles prepared.

(100 mL), NaOH (10 g), Na ₂ SO ₄ (10 g) and MeOH (10 g) were gently stirred to saponify the polyvinyl acetate / CNT nanocomposite particles. Polyvinyl acetate / CNT nanocomposite fine particles (1 g) were added to the prepared alkali solution, and the saponification reaction was carried out at 50 ° C for 30 hours. After the saponification reaction, it was washed several times with distilled water and dried at room temperature for 12 hours to prepare saponified polyvinyl alcohol / CNT powder.

The polyvinyl alcohol / CNT powder thus prepared was dispersed in the first polymer using a dry powder pulverization method and melt extruded in a nanocomposite film.

Then, a fibrous layer was formed on or in the film layer. Polyvinyl alcohol and distilled water were mixed as a first mixed solution to prepare a spinning solution. The prepared first mixed solution was centrifugally spinned on the film layer or the prepared fiber layer to form nanofibers, nanoparticles or microfiber layers. An adhesive was used to composite the film layer and the fiber layer. The detailed implementation will be described below.

Manufacturing example  1: polyethylene / (polyvinyl alcohol / CNT ) Production of film

After the polyvinyl alcohol / CNT (1 wt% CNT) powder was dispersed in polyethylene in a molten state, the extruder temperature was 220 ° C, the extrusion speed was 100 rpm, the twin screw length was 400 mm and the diameter was 24 mm and the film winding speed of the extruder was 5 m / To prepare a film.

Manufacturing example  2: polyethylene / (polyvinyl alcohol / CNT ) ( CNT  3 weight% ) Production of film

Except that polyvinyl alcohol / CNT (CNT: 3 wt%) powder was used instead of the polyvinyl alcohol / CNT (CNT: 3 wt%) powder.

Manufacturing example  3: polyethylene / (polyvinyl alcohol / CNT ) ( CNT  5 weight% ) Production of film

Except that polyvinyl alcohol / CNT (CNT 5% by weight) powder was used as a binder.

Example  1: polyethylene / (polyvinyl alcohol / CNT ) On film Polyvinyl acetate  Centrifugal spinning of nanofibers

A polyethylene / (polyvinyl alcohol / CNT) film (1 wt%) was added to the collector portion of the centrifugal radiator, and 10 wt% of vinyl acetate was dissolved in methanol, and then the solution was injected at 3000 rpm at a rate of 35 mL / By proceeding, a fibrous layer was formed to produce a film / fiber composite sheet.

Example  2: polyethylene / (polyvinyl alcohol / CNT ) On film Polyvinyl acetate  Centrifugal spinning of nanofibers

A polyethylene / (polyvinyl alcohol / CNT) film (3% by weight) was added to the collector of the centrifugal emitter, and 10% by weight of vinyl acetate was dissolved in methanol. The solution was then fed at 3000 rpm at a rate of 35 mL / By proceeding, a fibrous layer was formed to produce a film / fiber composite sheet.

Example  3: polyethylene / (polyvinyl alcohol / CNT ) On film Polyvinyl acetate  Centrifugal spinning of nanofibers

A polyethylene / (polyvinyl alcohol / CNT) film (5% by weight) was placed in a collector portion of a centrifugal radiator, and 10% by weight of vinyl acetate was dissolved in methanol, and the mixture was fed at 3000 rpm at a rate of 35 mL / By proceeding, a fibrous layer was formed to produce a film / fiber composite sheet.

Example  4: Polyvinyl acetate  After centrifugally spinning the nanofibers, polyethylene and polyvinyl alcohol / CNT  Powder was extruded to produce film

10% by weight of polyvinyl acetate was dissolved in methanol and then charged at 3000 rpm at a rate of 35 mL / min to carry out centrifugal spinning to form a fibrous layer. Polyethylene and 1% by weight of polyvinyl alcohol / CNT powder were dispersed Extruded under the conditions of an extruder temperature of 220 캜, an extrusion speed of 100 rpm, a twin screw length of 400 mm, a diameter of 24 mm and a film winding speed of 5 m / min in an extruder to form a film to produce a film / fiber composite sheet.

Example  5: Polyvinyl acetate  After centrifugally spinning the nanofibers, polyethylene and polyvinyl alcohol / CNT  Powder was extruded to produce film

10% by weight of polyvinyl acetate was dissolved in methanol and then charged at 3000 rpm at a rate of 35 mL / min to conduct centrifugal spinning to form a fiber layer. Polyethylene and 3% by weight of polyvinyl alcohol / CNT powder were dispersed Extruded under the conditions of an extruder temperature of 220 캜, an extrusion speed of 100 rpm, a twin screw length of 400 mm, a diameter of 24 mm and a film winding speed of 5 m / min in an extruder to form a film to produce a film / fiber composite sheet.

Example  6: Polyvinyl acetate  After centrifugally spinning the nanofibers, polyethylene and polyvinyl alcohol / CNT  Powder was extruded to produce film

10% by weight of polyvinyl acetate was dissolved in methanol and then charged at 3000 rpm at a rate of 35 mL / min to carry out centrifugal spinning to form a fibrous layer. Polyethylenes and 5% by weight of polyvinyl alcohol / CNT powder Extruded under the conditions of an extruder temperature of 270 占 폚, an extrusion rate of 60 rpm, a twin screw length of 400 mm, a diameter of 24 mm, and a film winding speed of 5 m / min.

Experimental Example  One : Carbon nanomaterials  Identify Polymer Particles Containing

1 g of the carbon nanomaterial was added to 100 g of the vinyl acetate monomer, and the mixture was polymerized by suspension polymerization to prepare polyvinyl acetate / carbon nanomaterial polymer microparticles. The produced fine particles are subjected to nonuniform saponification at a temperature of 30-100 deg. C for 50-150 hours in an alkali solution to prepare polyvinyl alcohol / carbon nanomaterial nanocomposite microparticles or polyvinyl alcohol / carbon nanomaterial nanocomposite microparticles .

As a result, in the case of a polymer containing no carbon nanomaterial, black particles can not be observed by an optical microscope (left side of FIG. 8), and in the case of a polymer incorporating a carbon material, (Fig. 8, right-hand side photograph). The polymer microparticles prepared by the heterogeneous system saponification method have a skin / core shape, the component corresponding to the skin is polyvinyl alcohol by nonuniform saponification, and the component corresponding to the core is polyvinyl acetate which is not heterogeneous saponification .

The polymer microparticles prepared according to the manufacturing method of FIG. 6 were able to uniformly incorporate the carbon nanomaterial. Carbon nanomaterials were mixed regardless of progress of heterogeneous saponification, and carbon nanomaterials were uniformly dispersed even though they were chemically modified by heterogeneous saponification of these polymer fine particles.

Experimental Example  2 : Carbon nano materials  Confirm microscope of mixed film / fiber composite sheet

As shown in FIGS. 2 and 4, a fiber / fiber composite sheet is formed on the fibrous layer, fibers are prepared by centrifugal spinning of the second polymer, and the first polymer fine particles mixed with the carbon nanomaterial are dispersed on the fibrous layer. . The film / fiber composite sheet produced by melt-bonding was uneven as a sheet in the form of fiber thickness (FIG. 9). The produced film / fiber composite sheet means that the film sheet using the first polymer fine particles mixed with the carbon nanomaterial can be combined with the fiber made of the second polymer.

Experimental Example  3: Confirmation of mechanical properties

One of the experiments was prepared as described in Examples 4-6, and another experiment was conducted without incorporating the carbon nanomaterials in Examples 4-6. The composite sheet film thus prepared was measured for maximum load, tensile strength and elongation using a universal tensile tester. As a result, it was confirmed that the composite sheet of PE / PVA / CNT film / PVAc fiber was improved by about 2 times in terms of maximum load, 1.6 times in terms of tensile strength, and 2.5 times in terms of elongation (Fig. 10). This means that the composite film containing the carbon nanomaterial can be excellently improved in maximum load, tensile strength and elongation.

Claims (17)

A water phase comprising carbon nanomaterials; And a vinyl acetate-based monomer, thereby producing spherical poly (vinyl acetate) microparticles incorporating the carbon nanomaterial;
A second step of producing nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol dispersed in a carbon nanomaterial by non-uniformly saponifying spherical polyvinyl acetate mixed with the carbon nanomaterial; And
And a third step of dispersing and melting-bonding the carbon nanomaterial / polyvinyl alcohol nanocomposite fine particles prepared in the above-mentioned first polymer in a molten state to produce a polymer film having carbon nanomaterial dispersed therein.
A method for producing a polymer film in which carbon nanomaterials are dispersed.
A water phase comprising carbon nanomaterials; And a vinyl acetate-based monomer, thereby producing spherical poly (vinyl acetate) microparticles incorporating the carbon nanomaterial;
A second step of producing nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol dispersed in a carbon nanomaterial by non-uniformly saponifying spherical polyvinyl acetate mixed with the carbon nanomaterial;
A third step of dispersing the nanocomposite particles of the carbon nanomaterial / polyvinyl alcohol produced in the above-mentioned first polymer in a molten state and melt-pressing them to produce a polymer film in which the carbon nanomaterial is dispersed; And
And spinning the second polymer spinning solution on the film to form a fiber layer.
A method for producing a composite sheet comprising a first polymer film and a second polymer fiber layer in which a carbon nanomaterial is dispersed.
A water phase comprising carbon nanomaterials; And a vinyl acetate-based monomer, thereby producing spherical poly (vinyl acetate) microparticles incorporating the carbon nanomaterial;
A second step of producing nanocomposite particles of a spherical carbon nanomaterial / polyvinyl alcohol dispersed in a carbon nanomaterial by non-uniformly saponifying spherical polyvinyl acetate mixed with the carbon nanomaterial; And
The nanocomposite fine particles of the carbon nanomaterial / polyvinyl alcohol and the first polymer are laminated on the fibrous layer formed by spinning the second polymer spinning solution and melt-pressed to produce a first polymer film in which the carbon nanomaterial is dispersed Step 3:
A method for producing a composite sheet comprising a first polymer film in which a carbon nanomaterial is dispersed and a second polymer fiber layer.
4. The method according to any one of claims 1 to 3,
Wherein the step (3) is a step of laminating one or more nanocomposite particles in multiple layers, followed by melt-pressing.
4. The method of claim 2 or 3, wherein the second polymer is selected from the group consisting of polyethylene (LDPE, HDPE), polypropylene, polyisobutylene, polyamide (nylon 6, nylon 66), polyester, and polystyrene acetal Wherein the polymer comprises a copolymer or blend polymer thereof.
4. The method according to any one of claims 1 to 3,
Wherein the carbon nanomaterial is selected from the group consisting of carbon nanotubes, graphite, graphene, and graphite.
4. The method according to any one of claims 1 to 3,
Wherein the content of the carbon nanomaterial in the nanocomposite fine particles of the carbon nanomaterial / polyvinyl alcohol is 0.01 wt% to 30 wt%.
4. The method according to any one of claims 1 to 3,
Wherein the nanocomposite particles of the carbon nanomaterial / polyvinyl alcohol further comprise functional inorganic nanoparticles.
9. The method of claim 8,
Wherein the functional inorganic nanoparticles are selected from the group consisting of metal nanoparticles, nanowires, oxide nanoparticles, porous nanomaterials, quantum dots and aerosols.
10. The method of claim 9,
Wherein the metal nanoparticles are selected from the group consisting of Ag, Au, clay, TiO ₂ , SiO ₂ , ZnO, Nano-diamond, Fe ₃ O ₄ and Fullerene. .
4. The method according to any one of claims 1 to 3,
The temperature during extrusion molding is 150 to 300 占 폚, the extrusion speed is 50 to 200 rpm, and the film winding speed of the extrusion molding machine is 1 to 10 m / min.
The method according to claim 2 or 3,
Wherein the concentration of the second polymer in the spinning solution is 1 wt% to 30 wt%.
The method according to claim 2 or 3,
Wherein said radiation forms a randomly-shaped fibrous nonwoven fabric by electrospinning, or forms a fibrous nonwoven fabric in a form aligned by centrifugal spinning.
14. The method of claim 13,
Wherein said centrifugal spinning forms a fibrous layer comprising at least one shape selected from the group consisting of microfibers, nanofibers, nanoparticles and microparticles according to process parameters of centrifugal spinning.
The method according to claim 2 or 3,
Wherein the fiber layer further comprises a carbon nanomaterial and a functional inorganic nanoparticle.
A first polymeric film layer in which a carbon nanomaterial is dispersed; And
And a second polymer fiber layer formed on the film layer,
A process for producing a polyurethane foam comprising the steps of:
A composite sheet comprising a first polymer film and a second polymer fiber layer in which carbon nanomaterials are dispersed.
Wherein the second polymeric fiber layer comprises a first polymeric film layer in which the carbon nanomaterial is dispersed,
A process for producing a polyurethane foam comprising the steps of:
A composite sheet comprising a first polymer film and a second polymer fiber layer in which carbon nanomaterials are dispersed.

Images