EP2256236A1 - Method for manufacturing conducting composite fibres with high nanotube content - Google Patents
Method for manufacturing conducting composite fibres with high nanotube content Download PDFInfo
- Publication number
- EP2256236A1 EP2256236A1 EP10163360A EP10163360A EP2256236A1 EP 2256236 A1 EP2256236 A1 EP 2256236A1 EP 10163360 A EP10163360 A EP 10163360A EP 10163360 A EP10163360 A EP 10163360A EP 2256236 A1 EP2256236 A1 EP 2256236A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- nanotubes
- fiber
- conductive composite
- fibers
- dispersion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F1/00—General methods for the manufacture of artificial filaments or the like
- D01F1/02—Addition of substances to the spinning solution or to the melt
- D01F1/09—Addition of substances to the spinning solution or to the melt for making electroconductive or anti-static filaments
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/02—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D01F6/14—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polymers of unsaturated alcohols, e.g. polyvinyl alcohol, or of their acetals or ketals
Definitions
- the present invention relates to a process for obtaining conductive composite fibers based on homo- or copolymer of vinyl alcohol with a high content of nanotubes capable of providing thermal and / or electrical conduction, in particular of carbon nanotubes. It also relates to the conductive composite fibers obtainable by this method, as well as their uses.
- Carbon nanotubes are known and possess particular crystalline structures, tubular, hollow and closed, composed of atoms arranged regularly in pentagons, hexagons and / or heptagons, obtained from carbon.
- CNTs generally consist of one or more graphite sheets wound coaxially.
- SWNTs single wall nanotubes
- Multi Wall Nanotubes or MWNTs Multi Wall Nanotubes
- CNTs have many powerful properties, namely electrical, thermal, chemical and mechanical.
- composite materials intended in particular for the automotive, nautical and aeronautical industries, electromechanical actuators, cables, resistant wires, chemical detectors, energy storage and conversion, electron emission displays, electronic components, and functional textiles.
- conductive such as NTCs allow the heat and electrical dissipation of heat and electric charges arising during friction.
- the CNTs when synthesized, are in the form of a disorganized powder, consisting of entangled filaments, which makes them difficult to implement in order to exploit their properties. In particular, to exploit their mechanical and / or electrical properties on a macroscopic scale, it is necessary for the CNTs to be present in large quantities and oriented in a preferred direction.
- Another approach for producing CNT-loaded polymer fibers is to mix the nanotubes and a polymer in the same solution before spinning.
- the solution thus produced is then injected into a static bath or in a flow which induces the coagulation of the polymer.
- the nanotubes mixed with the polymer are trapped in the structure and the final object is a composite fiber loaded with carbon nanotubes.
- the advantage of this principle is that it relies on the coagulation of the polymer and not directly on the coagulation of the nanotubes. Coagulation of the polymer allows consolidated fibers to be obtained more rapidly which can be easily handled and extracted from the coagulation baths to be, for example, washed, dried, drawn and wound.
- the spinning of polymer fibers by solvent coagulation and their treatments are well described in the literature.
- the fibers described by Zhang et al. contain a mass fraction of not more than 3% of carbon nanotubes.
- process according to the invention may optionally comprise other preliminary, intermediate and / or subsequent stages to those mentioned above, provided that these do not adversely affect the formation of the conductive composite fiber. .
- fiber is meant, within the meaning of the present invention, a strand whose diameter is between 100 nm (nanometers) and 300 microns (micrometers), preferably between 1 and 100 microns (micrometers), better, between 2 and 50 ⁇ m (micrometers).
- This structure may also be porous or non-porous.
- a fiber is intended to ensure the holding of a mechanical part and does not constitute a tube or pipe for the transport of a fluid.
- the nanotubes consist of at least one chemical element chosen from the elements of columns IIIa, IVa and Va of the periodic table.
- the nanotubes must be capable of providing thermal and / or electrical conduction; they can thus be based on boron, carbon, nitrogen, phosphorus or silicon.
- they may be constituted or contain carbon, carbon nitride, nitride of boron, boron carbide, boron phosphide, phosphorus nitride or carbon boronitride, or silicon.
- carbon nanotubes are used. These are graphitic carbon fibrils, hollow, each having one or more graphitic tubular walls oriented along the axis of the fibril.
- the nanotubes usually have a mean diameter ranging from 0.1 to 100 nm (nanometers), more preferably from 0.4 to 50 nm (nanometers) and better still from 1 to 30 nm (nanometers) and advantageously a length of 0, 1 to 10 ⁇ m (micrometers).
- Their length / diameter ratio is preferably greater than 10 and most often greater than 100 or even greater than 1000.
- Their specific surface area is, for example, between 100 and 500 m 2 / g (including limits), generally between 100 and 300 m 2.
- the multiwall nanotubes may for example comprise from 5 to 15 sheets (or walls) and more preferably from 7 to 10 sheets. These nanotubes can be treated or not.
- Carbon nanotubes are commercially available or can be prepared by known methods.
- An example of crude carbon nanotubes is especially commercially available from the company Arkema France under the trade name Graphistrength® ® C100.
- Hyperion Catalysis International Inc. describes the synthesis of carbon nanotubes. More particularly, the process comprises contacting a metal-based particle such as, in particular, iron, cobalt or nickel, with a gaseous compound based on carbon, at a temperature of between 850 ° C. and 1200 ° C. C, the dry weight proportion of the carbon-based compound relative to the metal-based particle being at least about 100: 1.
- a metal-based particle such as, in particular, iron, cobalt or nickel
- nanotubes may be, optionally and optionally in combination, purified, treated (for example oxidized) and / or milled before being used in the process according to the invention.
- the grinding of the nanotubes may in particular be carried out cold or hot and be carried out according to the known techniques used in devices such as ball mills, hammers, grinders, knives, jet gas or any other system grinding capable of reducing the size of the entangled network of nanotubes. It is preferred that this grinding step is performed according to a gas jet grinding technique and in particular in an air jet mill, or in a ball mill.
- the purification of the crude or milled nanotubes can be carried out by washing with a sulfuric acid solution, so as to rid them of any residual mineral and metallic impurities originating from their preparation process.
- the weight ratio of the nanotubes to the sulfuric acid may especially be between 1: 2 and 1: 3 (limits included).
- the purification operation may also be carried out at a temperature ranging from 90 to 120 ° C, for example for a period of 5 to 10 hours. This operation may advantageously be followed by rinsing steps with water and drying the purified nanotubes.
- the purification may also consist of a heat treatment at high temperature, typically greater than 1000 ° C.
- the oxidation of the nanotubes is advantageously carried out by putting them in contact with a solution of sodium hypochlorite containing from 0.5 to 15% by weight of NaOCl and preferably from 1 to 10% by weight of NaOCl, for example in a weight ratio of nanotubes to sodium hypochlorite ranging from 1: 0.1 to 1: 1.
- the oxidation is advantageously carried out at a temperature below 60 ° C. and preferably at room temperature, for a duration ranging from a few minutes to 24 hours. This oxidation operation may advantageously be followed by filtration and / or centrifugation, washing and drying steps of the oxidized nanotubes.
- the nanotubes In order to eliminate the catalyst metal residues, it is also possible to subject the nanotubes to a heat treatment of at least 1000 ° C., for example 1200 ° C.
- the first step of the process according to the invention consists in forming a dispersion of nanotubes in a solution of homo- or copolymer of vinyl alcohol, in the presence of at least one stabilizing agent covalently or non-covalently bonded to the nanotubes.
- the homo- or copolymer of vinyl alcohol is the polyvinyl alcohol itself.
- its molecular weight may be between 5,000 and 300,000 g / mol. Its degree of hydrolysis may be greater than 96%, or even greater than 99%.
- the term "stabilizing agent” is intended to mean a compound that allows homogeneous dispersion of the nanotubes in the solution, which protects the nanotubes from coagulation in the presence of the homo- or copolymer of vinyl alcohol, but which does not interfere with the coagulation of the homo- or copolymer of vinyl alcohol in a coagulation solution.
- the stabilizing agent (s) according to the invention are bonded to the nanotubes either covalently or non-covalently.
- the stabilizing agent is non-covalently bonded to the nanotubes, it may be chosen from essentially nonionic surfactants.
- the term "essentially nonionic surfactant” is intended to mean a nonionic amphiphilic compound, cited for example in McCutcheon's 2008 "Emulsifiers and Detergents", and preferably having an HLB (hydrophilic-lipophilic balance). from 13 to 16, as well as block copolymers containing hydrophilic blocks and lipophilic blocks and having a low ionicity, for example 0% to 10% by weight of ionic monomer and 90% to 100% of nonionic monomer.
- HLB hydrophilic-lipophilic balance
- the stabilizing agent is covalently bonded to the nanotubes
- it is preferably a hydrophilic group, preferably a polyethylene glycol group grafted onto the nanotubes.
- the grafting of reactive units such as polyethylene glycol groups on the surface of the nanotubes can be carried out according to any method known to those skilled in the art.
- the person skilled in the art may relate to the publication of B. Zhao et al. (Synthesis and Characterization of Water Soluble Single-Walled Carbon Nanotube Graft Copolymers, J. Am Chem Soc. (2005) Vol 127 No 22 ).
- the nanotubes are dispersed in dimethylformamide (DMF) and are contacted with oxalyl chloride.
- DMF dimethylformamide
- PEG polyethylene glycol
- the nanotubes thus grafted are purified.
- the dispersion produced in the first step of the process according to the invention comprises a solvent which is preferably chosen from water, dimethylsulfoxide (DMSO), glycerol, ethylene glycol, diethylene glycol and triethylene glycol. , diethylene triamine, ethylene diamine, phenol, dimethylformamide (DMF), dimethylacetamide, N-methylpyrrolidone and mixtures thereof.
- a solvent which is preferably chosen from water, dimethylsulfoxide (DMSO), glycerol, ethylene glycol, diethylene glycol and triethylene glycol. , diethylene triamine, ethylene diamine, phenol, dimethylformamide (DMF), dimethylacetamide, N-methylpyrrolidone and mixtures thereof.
- the solvent is chosen from water, DMSO and mixtures thereof in all proportions.
- the pH of the aqueous dispersion can be maintained preferably between 3 and 5 by addition of one or more acids, which can be chosen from inorganic acids, such as sulfuric acid, nitric acid and hydrochloric acid, organic acids such as acetic acid, tartaric acid and oxalic acid and mixtures of organic acid and organic acid salt such as acid citric acid and sodium citrate, acetic acid and sodium acetate, tartaric acid and potassium tartrate, tartaric acid and sodium citrate.
- inorganic acids such as sulfuric acid, nitric acid and hydrochloric acid
- organic acids such as acetic acid, tartaric acid and oxalic acid and mixtures of organic acid and organic acid salt such as acid citric acid and sodium citrate, acetic acid and sodium acetate, tartaric acid and potassium tartrate, tartaric acid and sodium citrate.
- the dispersion may comprise boric acid, borate salts, or mixtures thereof.
- the dispersion may also comprise a salt selected from zinc chloride, sodium thiocyanate, calcium chloride, aluminum chloride, lithium chloride, rhodanates and mixtures thereof. They make it possible to optimize the rheological properties of the dispersion and to promote the formation of the fiber.
- the dispersion is carried out by means of ultrasound or a rotor-stator system or a ball mill. It can be carried out at room temperature, or by heating, for example, between 40 and 120 ° C.
- the dispersion thus produced during the first step of the process according to the invention may comprise from 2% to 30% by weight of homo- or copolymers of vinyl alcohol, from 0.1% to 5% of nanotubes, from 0.1% to 5% of stabilizing agent, relative to the total mass of the dispersion, including the solvent.
- the second step of the process consists in injecting said dispersion obtained during the first step into a coagulation solution to form a pre-fiber, in the form of monofilament or multi-filaments.
- coagulation solution means a solution which causes the homo- or copolymer of vinyl alcohol to solidify.
- the coagulation solution comprises a solvent chosen from water, an alcohol, a polyol, a ketone and their mixtures, more preferably a solvent chosen from water, methanol, ethanol, butanol, propanol, isopropanol, glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene and mixtures thereof, and even more preferably a solvent selected from water, methanol, ethanol, a glycol acetone and their mixtures.
- a solvent chosen from water, an alcohol, a polyol, a ketone and their mixtures more preferably a solvent chosen from water, methanol, ethanol, butanol, propanol, isopropanol, glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene and mixtures thereof, and even more preferably a solvent
- the coagulation solution advantageously has a temperature of between 10 and 80 ° C. If the solvent of the coagulation solution is essentially organic, such as methanol, the coagulation solution advantageously has a temperature between -30 and 10 ° C.
- the coagulation solution may comprise one or more salts intended to promote the coagulation of the homo- or copolymer of vinyl alcohol, chosen from alkaline salts or desiccant salts such as ammonium sulphate, sulphate of potassium, sodium sulfate, sodium carbonate, sodium hydroxide, potassium hydroxide and mixtures thereof.
- alkaline salts or desiccant salts such as ammonium sulphate, sulphate of potassium, sodium sulfate, sodium carbonate, sodium hydroxide, potassium hydroxide and mixtures thereof.
- the coagulation solution may comprise one or more additional compounds which are intended to improve the mechanical properties, the water resistance of the fiber and / or facilitate the spinning of the fiber.
- the coagulation solution may therefore comprise at least one compound selected from boric acid, borate salts and mixtures thereof.
- the coagulation solution is saturated with salts.
- the dispersion is injected during the second step of the process according to the invention through one or a set of needles and / or one or a set of nonporous cylindrical or conical nozzles into the coagulation solution, which can be static (static bath) or in motion (flow).
- the average injection speed of the dispersion may be between 0.1 m / min and 50 m / min, preferably between 0.5 m / min and 20 m / min.
- the coagulant solution induces coagulation in the form of a pre-fiber by solidification of the homo- or copolymer of vinyl alcohol.
- the nanotubes are trapped in the polymer that solidifies.
- the next step of the process according to the invention consists in extracting, continuously or not, the pre-fiber from the coagulation solution.
- the wash tank preferably includes water.
- the washing step can eliminate a portion of the peripheral polymer of the pre-fiber and thus enrich (up to 70% by weight) the composition of the pre-fiber into nanotubes.
- the washing bath may comprise agents which make it possible to modify the composition of the pre-fiber or which chemically interact with it.
- chemical or physical crosslinking agents in particular borate salts or dialdehydes, may be added to the bath to reinforce the pre-fiber.
- the washing step can also make it possible to eliminate the agents, in particular the surfactants, potentially detrimental to the mechanical or electrical properties of the fiber.
- a drying step is also included in the process according to the invention. This step can take place either directly after extraction or after washing. In particular, if it is desired to obtain a polymer-enriched fiber, it is desirable to dry the pre-fiber directly after the extraction.
- the drying is preferably carried out in an oven that will dry the pre-fiber through a gas flowing in an interior duct of the oven. The drying can also be carried out by infrared radiation.
- the method according to the invention may also comprise a winding step, and optionally a hot stretching step performed between the drying step and the winding step. It may also include stretching in solvents at different times.
- This stretching step may be carried out at a temperature above the glass transition temperature (Tg) of the homo- or copolymer of vinyl alcohol and preferably below its melting point (if it exists).
- Tg glass transition temperature
- Such a step, described in the patent US 6,331,265 enables the nanotubes and the polymer to be oriented substantially in the same direction, along the axis of the fiber, and thus to improve the mechanical properties of the latter, in particular its Young's modulus and its rupture threshold.
- the draw ratio defined as the ratio of the length of the fiber after drawing to its length before drawing, may be between 1 and 20, preferably between 1 and 10, included. Stretching can be done in one go, or several times, allowing the fiber to relax slightly between each stretch.
- This stretching step is preferably conducted by passing the fibers through a series of rolls having different rotational speeds, those which unroll the fiber rotating at a lower speed than those receiving it.
- the fibers may be passed through ovens arranged between the rolls, or heated rollers may be used, or these two techniques may be combined. This stretching step makes it possible to consolidate the fiber and to achieve high breaking point stresses.
- Another subject of the present invention is the conductive composite fibers that can be obtained according to the method of the invention.
- Said conductive composite fibers obtained are characterized in that they contain from 5 to 70% by weight of nanotubes, preferably from 5 to 50%, more preferably from 5 to 30%, and more preferably from 5 to 25%, by in relation to the total weight of the fibers. It is therefore possible to obtain composite fibers with a high content of nanotubes.
- the conductive composite fibers obtained according to this process have a resistivity which can be between 10 -3 and 10 5 ohm.cm at room temperature. This electrical conductivity can be further improved by heat treatments.
- the manufacture of these composite parts can be carried out according to various processes, generally involving a step of impregnating the composite fibers.
- conductive according to the invention by a polymeric composition containing at least one thermoplastic material, elastomeric or thermosetting.
- This impregnation step may itself be carried out according to various techniques, depending in particular on the physical form of the polymeric composition used (pulverulent or more or less liquid).
- the impregnation of the conductive composite fibers is preferably carried out according to a fluidized bed impregnation process, in which the polymeric composition is in the form of powder. Pre-impregnated fibers are thus obtained.
- preimpregnated fiber fabrics of identical or different composition, can be stacked to form a plate or a laminated material, or alternatively subjected to a thermoforming process.
- the pre-impregnated fibers may be combined to form ribbons which may be used in a filament winding process which makes it possible to obtain hollow pieces of almost unlimited shape, by winding the ribbons on a mandrel having the shape of the part to be made.
- the manufacture of the finished part comprises a step of consolidating the polymeric composition, which is for example melted locally to create zones for fixing the fibers pre-impregnated with each other and / or to secure the fiber ribbons pre-impregnated with each other. impregnated in the filament winding process.
- a film from the polymeric impregnating composition in particular by means of an extrusion or calendering process, said film having for example a thickness of about 100 ⁇ m, then of placing it between two conductive composite fiber mats according to the invention, the assembly then being hot pressed to allow the impregnation of the fibers and the manufacture of the composite part.
- the present invention thus has for another object composite materials comprising conductive composite fibers according to the invention, bonded together by weaving or by a polymeric composition.
- the dispersion was then injected into a static bath of a saturated sodium sulfate coagulant solution (320 g / L) at 40 ° C.
- the pre-fiber was extracted from the coagulation bath after a residence time of less than ten seconds. It was then dried by infra-red radiation, then redirected into a washing bath containing water. After 1 min, it was dried again by infrared radiation and then wound.
- the final fiber obtained contains 8% of nanotubes in mass. This value was obtained by thermogravimetric analysis (TGA).
- TGA thermogravimetric analysis
- the fiber is cylindrical and homogeneous and has been mechanically characterized by traction. It has a breaking energy of 475 J / g, an elongation at break of 425% stretching and a Young's modulus of 3 GPa. After hot stretching at 200 ° C of 400%, its Young's modulus increases to 29 GPa and its rupture threshold increases to 12% stretching.
- Composite fibers were made starting from aqueous dispersions of multiwall nanotubes. 0.9% by weight of nanotubes and 1.2% Brij®78 were dispersed in water. By the same method as described in Example 1, fibers loaded with 17% multiwall nanotubes were obtained.
- These fibers have the advantage of combining good mechanical properties with quite interesting electrical properties, since they are electrically conductive, with a resistivity of 10 ⁇ .cm. They have a toughness of 340 MPa, a Young's modulus of 5.5 GPa and an elongation at break of 240%.
- the solution was then injected into a static bath of a saturated sodium sulfate coagulant solution (320 g / L) at 40 ° C to form a fiber.
- the final fiber obtained contains 12% of nanotubes in mass. It has a toughness of 360 MPa, a Young's modulus of 4 GPa and an elongation at break of 325%, as well as a resistivity of 30 ⁇ .cm.
- Example 3 The dispersion described in Example 3 was injected into a coagulant bath containing sodium hydroxide (50 g / L) and sodium sulfate (300 g / L) at 40 ° C.
- the final fiber obtained contains 12% of nanotubes in mass. It has a toughness of 320 MPa, a Young's modulus of 7 GPa and an elongation at break of 200%, as well as a resistivity of 100 ⁇ .cm.
- the dispersion was then injected into a methanol coagulant bath at -20 ° C containing 10% DMSO to form 8% nanotube filled fibers.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Textile Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Artificial Filaments (AREA)
- Inorganic Fibers (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Reinforced Plastic Materials (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
La présente invention concerne un procédé d'obtention de fibres composites conductrices à base d'homo- ou de copolymère d'alcool vinylique à haute teneur en nanotubes capables d'assurer une conduction thermique et/ou électrique, en particulier en nanotubes de carbone. Elle concerne également les fibres composites conductrices susceptibles d'être obtenues par ce procédé, ainsi que leurs utilisations.The present invention relates to a process for obtaining conductive composite fibers based on homo- or copolymer of vinyl alcohol with a high content of nanotubes capable of providing thermal and / or electrical conduction, in particular of carbon nanotubes. It also relates to the conductive composite fibers obtainable by this method, as well as their uses.
Les nanotubes de carbone (ou NTC) sont connus et possèdent des structures cristallines particulières, de forme tubulaire, creuses et closes, composées d'atomes disposés régulièrement en pentagones, hexagones et/ou heptagones, obtenues à partir de carbone. Les NTC sont en général constitués d'un ou plusieurs feuillets de graphite enroulés coaxialement. On distingue ainsi les nanotubes monoparois (Single Wall Nanotubes ou SWNT) et les nanotubes multiparois (Multi Wall Nanotubes ou MWNT).Carbon nanotubes (or CNTs) are known and possess particular crystalline structures, tubular, hollow and closed, composed of atoms arranged regularly in pentagons, hexagons and / or heptagons, obtained from carbon. CNTs generally consist of one or more graphite sheets wound coaxially. One can distinguish single wall nanotubes (SWNTs) and multiwall nanotubes (Multi Wall Nanotubes or MWNTs).
Les NTC possèdent de nombreuses propriétés performantes, à savoir électriques, thermiques, chimiques et mécaniques. Parmi leurs applications, on peut citer, notamment, les matériaux composites destinés en particuliers à l'industrie automobile, nautique et aéronautique, les actionneurs électromécaniques, les câbles, les fils résistants, les détecteurs chimiques, le stockage et la conversion d'énergie, les afficheurs à émission d'électrons, les composants électroniques, et les textiles fonctionnels. Dans les domaines automobile, aéronautique et électronique, les charges conductrices telles que les NTC permettent la dissipation thermique et électrique de la chaleur et des charges électriques apparaissant lors de frottements.CNTs have many powerful properties, namely electrical, thermal, chemical and mechanical. Among their applications, there may be mentioned, in particular, composite materials intended in particular for the automotive, nautical and aeronautical industries, electromechanical actuators, cables, resistant wires, chemical detectors, energy storage and conversion, electron emission displays, electronic components, and functional textiles. In the automotive, aerospace and electronics fields, conductive such as NTCs allow the heat and electrical dissipation of heat and electric charges arising during friction.
Généralement, lorsqu'ils sont synthétisés, les NTC sont sous la forme d'une poudre désorganisée, constituée de filaments enchevêtrés, ce qui les rend difficile à mettre en oeuvre en vue de l'exploitation de leurs propriétés. Notamment, pour exploiter leurs propriétés mécaniques et/ou électriques à l'échelle macroscopique, il est nécessaire que les NTC soient présents en grandes quantités et orientés dans une direction privilégiée.Generally, when synthesized, the CNTs are in the form of a disorganized powder, consisting of entangled filaments, which makes them difficult to implement in order to exploit their properties. In particular, to exploit their mechanical and / or electrical properties on a macroscopic scale, it is necessary for the CNTs to be present in large quantities and oriented in a preferred direction.
La voie la plus classique pour incorporer des NTC dans des fibres polymères consiste à mélanger un ou plusieurs polymères thermoplastiques avec des nanotubes par voie fondue. Le mélange est ensuite extrudé pour former une fibre ou plusieurs fibres. Cette méthode est par exemple décrite dans la demande de brevet internationale
Une autre approche a été proposée dans la demande de brevet français
Une autre approche pour réaliser des fibres polymères chargées en NTC consiste à mélanger les nanotubes et un polymère dans une même solution avant le filage. La solution ainsi réalisée est ensuite injectée dans un bain statique ou en écoulement qui induit la coagulation du polymère. Les nanotubes mélangés au polymère se trouvent piégés dans la structure et l'objet final est une fibre composite chargée en nanotubes de carbone. L'avantage de ce principe est qu'il repose sur la coagulation du polymère et non directement sur la coagulation des nanotubes. La coagulation du polymère permet d'obtenir plus rapidement des fibres consolidées qui peuvent être facilement manipulées et extraites des bains de coagulation pour être, par exemple, lavées, séchées, étirées et bobinées. Le filage des fibres polymères par coagulation en voie solvant et leurs traitements sont bien décrits dans la littérature.Another approach for producing CNT-loaded polymer fibers is to mix the nanotubes and a polymer in the same solution before spinning. The solution thus produced is then injected into a static bath or in a flow which induces the coagulation of the polymer. The nanotubes mixed with the polymer are trapped in the structure and the final object is a composite fiber loaded with carbon nanotubes. The advantage of this principle is that it relies on the coagulation of the polymer and not directly on the coagulation of the nanotubes. Coagulation of the polymer allows consolidated fibers to be obtained more rapidly which can be easily handled and extracted from the coagulation baths to be, for example, washed, dried, drawn and wound. The spinning of polymer fibers by solvent coagulation and their treatments are well described in the literature.
Cette approche a ainsi été adoptée par
Dans une autre publication,
Il a été envisagé par la Demanderesse d'adapter le procédé ci-dessus en soumettant les NTC à un traitement oxydant, de façon à créer à leur surface des groupes polaires. Cette solution ne permet toutefois pas d'éviter la coagulation des NTC en présence de PVA. Le recours à des tensioactifs ioniques de type laurylsulfate de sodium (SDS) ne permet pas non plus d'éviter cette coagulation. Il a par ailleurs été envisagé d'inclure du poly(acide acrylique) pour remédier à ce problème. Il a toutefois été observé que celui-ci inhibait la coagulation ultérieure du PVA et donc la formation de la fibre.It has been envisaged by the Applicant to adapt the above method by subjecting the CNTs to an oxidizing treatment, so as to create on their surface polar groups. This solution, however, does not prevent coagulation of CNTs in the presence of PVA. The use of ionic surfactants of the sodium lauryl sulphate (SDS) type also does not make it possible to avoid this coagulation. It was also envisaged to include poly (acid) acrylic) to remedy this problem. It has been observed, however, that this inhibits the subsequent coagulation of the PVA and thus the formation of the fiber.
Il subsiste donc le besoin de proposer un procédé simple permettant de préparer des fibres composites conductrices homogènes à haute teneur en nanotubes, c'est à dire renfermant au moins 5% en poids de nanotubes. De plus, il subsiste aussi le besoin de fabriquer des fibres ayant un seuil de rupture mécanique supérieur à 100 MPa.There remains therefore the need to provide a simple method for preparing homogeneous conductive composite fibers with high content of nanotubes, that is to say containing at least 5% by weight of nanotubes. In addition, there is also the need to manufacture fibers having a mechanical break point greater than 100 MPa.
La Demanderesse a découvert que ces besoins pouvaient être satisfaits par la mise en oeuvre d'un procédé de fabrication de fibres composites conductrices, dans lequel des nanotubes mis en dispersion dans une solution d'homo- ou copolymère d'alcool vinylique sont stabilisés grâce à des agents stabilisants.The Applicant has discovered that these needs could be satisfied by the implementation of a process for manufacturing conductive composite fibers, in which nanotubes dispersed in a solution of homo- or copolymer of vinyl alcohol are stabilized by means of stabilizing agents.
La présente invention a ainsi pour objet un procédé de fabrication d'une fibre composite conductrice, comprenant les étapes successives consistant en :
- a) la formation d'une dispersion de nanotubes capables d'assurer une conduction thermique et/ou électrique et d'au moins un élément chimique choisi parmi les éléments des colonnes IIIa, IVa et Va du tableau périodique, dans une solution d'homo- ou copolymère d'alcool vinylique, en présence d'au moins un agent stabilisant lié de façon covalente ou non covalente aux nanotubes,
- b) l'injection de ladite dispersion dans une solution de coagulation pour former une pré-fibre,
- c) l'extraction de ladite pré-fibre,
- d) le lavage éventuel de ladite pré-fibre,
- e) le séchage de ladite pré-fibre pour obtenir une fibre renfermant de 5 à 70% en poids de nanotubes, par rapport au poids total de la fibre.
- a) forming a dispersion of nanotubes capable of providing thermal and / or electrical conduction and of at least one chemical element chosen from the elements of columns IIIa, IVa and Va of the periodic table, in a solution of homo or a vinyl alcohol copolymer, in the presence of at least one stabilizing agent covalently or non-covalently bound to the nanotubes,
- b) injecting said dispersion into a coagulation solution to form a pre-fiber,
- c) extracting said pre-fiber,
- d) the possible washing of said pre-fiber,
- e) drying said pre-fiber to obtain a fiber containing from 5 to 70% by weight of nanotubes, relative to the total weight of the fiber.
Il est bien entendu que le procédé selon l'invention peut éventuellement comprendre d'autres étapes préliminaires, intermédiaires et/ou subséquentes à celles mentionnées ci-dessus, pour autant que celles-ci n'affectent pas négativement la formation de la fibre composite conductrice.It is understood that the process according to the invention may optionally comprise other preliminary, intermediate and / or subsequent stages to those mentioned above, provided that these do not adversely affect the formation of the conductive composite fiber. .
En préambule, il est précisé que, dans l'ensemble de cette description, l'expression "compris(e) entre" doit être interprétée comme incluant les bornes citées.In the preamble, it is specified that, throughout this description, the expression "included (e) between" must be interpreted as including the boundaries cited.
Par « fibre », on entend, au sens de la présente invention, un brin dont le diamètre est compris entre 100 nm (nanomètres) et 300 µm (micromètres), de préférence entre 1 et 100 µm (micromètres), mieux, entre 2 et 50 µm (micromètres). Cette structure peut par ailleurs être ou non poreuse. Sur le plan de ses utilisations, une fibre est destinée à assurer la tenue d'une pièce mécanique et ne constitue pas un tube ou canalisation destiné au transport d'un fluide.By "fiber" is meant, within the meaning of the present invention, a strand whose diameter is between 100 nm (nanometers) and 300 microns (micrometers), preferably between 1 and 100 microns (micrometers), better, between 2 and 50 μm (micrometers). This structure may also be porous or non-porous. In terms of its uses, a fiber is intended to ensure the holding of a mechanical part and does not constitute a tube or pipe for the transport of a fluid.
Selon l'invention, les nanotubes sont constitués d'au moins un élément chimique choisi parmi les éléments des colonnes IIIa, IVa et Va du tableau périodique. Les nanotubes doivent être capables d'assurer une conduction thermique et/ou électrique ; ils peuvent ainsi être à base de bore, de carbone, d'azote, de phosphore ou de silicium. Par exemple, ils peuvent être constitué ou contenir du carbone, du nitrure de carbone, du nitrure de bore, du carbure de bore, du phosphure de bore, du nitrure de phosphore ou du boronitrure de carbone, ou encore du silicium.According to the invention, the nanotubes consist of at least one chemical element chosen from the elements of columns IIIa, IVa and Va of the periodic table. The nanotubes must be capable of providing thermal and / or electrical conduction; they can thus be based on boron, carbon, nitrogen, phosphorus or silicon. For example, they may be constituted or contain carbon, carbon nitride, nitride of boron, boron carbide, boron phosphide, phosphorus nitride or carbon boronitride, or silicon.
De préférence, on utilise des nanotubes de carbone (ou « NTC »). Il s'agit de fibrilles de carbone graphitique, creuses, comportant chacune une ou plusieurs parois tubulaires graphitiques orientées selon l'axe de la fibrille. Les nanotubes ont habituellement un diamètre moyen allant de 0,1 à 100 nm (nanomètres), plus préférentiellement de 0,4 à 50 nm (nanomètres) et, mieux, de 1 à 30 nm (nanomètres) et avantageusement une longueur de 0,1 à 10 µm (micromètres). Leur rapport longueur/diamètre est de préférence supérieur à 10 et le plus souvent supérieur à 100 voire supérieur à 1000. Leur surface spécifique est par exemple comprise entre 100 et 500 m2/g (bornes comprises), généralement entre 100 et 300 m2/g pour les nanotubes multiparois, et elle peut même aller jusqu'à 1300 m2/g dans le cas des nanotubes monoparois. Leur densité apparente peut notamment être comprise entre 0,05 et 0,5 g/cm3 (bornes comprises) et plus préférentiellement entre 0,1 et 0,2 g/cm3 (bornes comprises). Les nanotubes multiparois peuvent par exemple comprendre de 5 à 15 feuillets (ou parois) et plus préférentiellement de 7 à 10 feuillets. Ces nanotubes peuvent être traités ou non.Preferably, carbon nanotubes (or "CNTs") are used. These are graphitic carbon fibrils, hollow, each having one or more graphitic tubular walls oriented along the axis of the fibril. The nanotubes usually have a mean diameter ranging from 0.1 to 100 nm (nanometers), more preferably from 0.4 to 50 nm (nanometers) and better still from 1 to 30 nm (nanometers) and advantageously a length of 0, 1 to 10 μm (micrometers). Their length / diameter ratio is preferably greater than 10 and most often greater than 100 or even greater than 1000. Their specific surface area is, for example, between 100 and 500 m 2 / g (including limits), generally between 100 and 300 m 2. / g for multiwall nanotubes, and it can even go up to 1300 m 2 / g in the case of single-walled nanotubes. Their apparent density may especially be between 0.05 and 0.5 g / cm 3 (inclusive) and more preferably between 0.1 and 0.2 g / cm 3 (inclusive). The multiwall nanotubes may for example comprise from 5 to 15 sheets (or walls) and more preferably from 7 to 10 sheets. These nanotubes can be treated or not.
Les nanotubes de carbone sont disponibles dans le commerce ou peuvent être préparés par des méthodes connues. Un exemple de nanotubes de carbone bruts est notamment disponible dans le commerce auprès de la société ARKEMA France sous la dénomination commerciale Graphistrength® C100.Carbon nanotubes are commercially available or can be prepared by known methods. An example of crude carbon nanotubes is especially commercially available from the company Arkema France under the trade name Graphistrength® ® C100.
Il existe plusieurs procédés de synthèse de nanotubes de carbone, notamment la décharge électrique, l'ablation laser et le dépôt chimique en phase vapeur ou CVD (Chemical Vapour Deposition) qui permet d'assurer la fabrication en grande quantité de nanotubes de carbone et donc leur obtention à un prix de revient compatible avec leur utilisation massive. Ce procédé consiste précisément à injecter une source de carbone à relativement haute température sur un catalyseur qui peut lui-même être constitué d'un métal tel que le fer, le cobalt, le nickel ou le molybdène, supporté sur un solide inorganique tel que l'alumine, la silice ou la magnésie. Les sources de carbone peuvent comprendre le méthane, l'éthane, l'éthylène, l'acétylène, l'éthanol, le bio-éthanol, le méthanol, voire un mélange de monoxyde de carbone et d'hydrogène (procédé HIPCO).There are several processes for synthesizing carbon nanotubes, including electrical discharge, laser ablation and CVD (Chemical Vapor Deposition), which allows the production of large quantities of carbon nanotubes and therefore their obtaining at a cost price compatible with their massive use. This process consists precisely in injecting a source of carbon at relatively high temperature over a catalyst which may itself consist of a metal such as iron, cobalt, nickel or molybdenum, supported on an inorganic solid such as alumina, silica or magnesia. Carbon sources may include methane, ethane, ethylene, acetylene, ethanol, bioethanol, methanol or even a mixture of carbon monoxide and hydrogen (HIPCO process).
Ainsi la demande
Ces nanotubes peuvent être, au choix et éventuellement en combinaison, purifiés, traités (par exemple oxydés) et/ou broyés, avant leur mise en oeuvre dans le procédé selon l'invention.These nanotubes may be, optionally and optionally in combination, purified, treated (for example oxidized) and / or milled before being used in the process according to the invention.
Le broyage des nanotubes peut être notamment effectué à froid ou à chaud et être réalisé selon les techniques connues mises en oeuvre dans des appareils tels que des broyeurs à boulets, à marteaux, à meules, à couteaux, à jet de gaz ou tout autre système de broyage susceptible de réduire la taille du réseau enchevêtré de nanotubes. On préfère que cette étape de broyage soit pratiquée selon une technique de broyage par jet de gaz et en particulier dans un broyeur à jet d'air, ou dans un broyeur à bille.The grinding of the nanotubes may in particular be carried out cold or hot and be carried out according to the known techniques used in devices such as ball mills, hammers, grinders, knives, jet gas or any other system grinding capable of reducing the size of the entangled network of nanotubes. It is preferred that this grinding step is performed according to a gas jet grinding technique and in particular in an air jet mill, or in a ball mill.
La purification des nanotubes bruts ou broyés peut être réalisée par lavage à l'aide d'une solution d'acide sulfurique, de manière à les débarrasser d'éventuelles impuretés minérales et métalliques résiduelles, provenant de leur procédé de préparation. Le rapport pondéral des nanotubes à l'acide sulfurique peut notamment être compris entre 1:2 et 1:3 (bornes incluses). L'opération de purification peut par ailleurs être effectuée à une température allant de 90 à 120°C, par exemple pendant une durée de 5 à 10 heures. Cette opération peut avantageusement être suivie d'étapes de rinçage à l'eau et de séchage des nanotubes purifiés. La purification peut aussi consister en un traitement thermique à haute température, typiquement supérieure à 1 000°C.The purification of the crude or milled nanotubes can be carried out by washing with a sulfuric acid solution, so as to rid them of any residual mineral and metallic impurities originating from their preparation process. The weight ratio of the nanotubes to the sulfuric acid may especially be between 1: 2 and 1: 3 (limits included). The purification operation may also be carried out at a temperature ranging from 90 to 120 ° C, for example for a period of 5 to 10 hours. This operation may advantageously be followed by rinsing steps with water and drying the purified nanotubes. The purification may also consist of a heat treatment at high temperature, typically greater than 1000 ° C.
L'oxydation des nanotubes est avantageusement réalisée en mettant ceux-ci en contact avec une solution d'hypochlorite de sodium renfermant de 0,5 à 15% en poids de NaOCl et de préférence de 1 à 10% en poids de NaOCl, par exemple dans un rapport pondéral des nanotubes à l'hypochlorite de sodium allant de 1:0,1 à 1:1. L'oxydation est avantageusement réalisée à une température inférieure à 60°C et de préférence à température ambiante, pendant une durée allant de quelques minutes à 24 heures. Cette opération d'oxydation peut avantageusement être suivie d'étapes de filtration et/ou centrifugation, lavage et séchage des nanotubes oxydés.The oxidation of the nanotubes is advantageously carried out by putting them in contact with a solution of sodium hypochlorite containing from 0.5 to 15% by weight of NaOCl and preferably from 1 to 10% by weight of NaOCl, for example in a weight ratio of nanotubes to sodium hypochlorite ranging from 1: 0.1 to 1: 1. The oxidation is advantageously carried out at a temperature below 60 ° C. and preferably at room temperature, for a duration ranging from a few minutes to 24 hours. This oxidation operation may advantageously be followed by filtration and / or centrifugation, washing and drying steps of the oxidized nanotubes.
Afin d'éliminer les résidus métalliques de catalyseur, il est également possible de soumettre les nanotubes à un traitement thermique d'au moins 1000°C, par exemple de 1200°C.In order to eliminate the catalyst metal residues, it is also possible to subject the nanotubes to a heat treatment of at least 1000 ° C., for example 1200 ° C.
La première étape du procédé selon l'invention consiste à former une dispersion de nanotubes dans une solution d'homo- ou copolymère d'alcool vinylique, en présence d'au moins un agent stabilisant lié de façon covalente ou non covalente aux nanotubes. De manière avantageuse, l'homo- ou copolymère d'alcool vinylique est le poly(alcool vinylique) lui-même.The first step of the process according to the invention consists in forming a dispersion of nanotubes in a solution of homo- or copolymer of vinyl alcohol, in the presence of at least one stabilizing agent covalently or non-covalently bonded to the nanotubes. Advantageously, the homo- or copolymer of vinyl alcohol is the polyvinyl alcohol itself.
Selon la nature de la solution réalisée et la nature du polymère, sa masse moléculaire peut être comprise entre 5 000 et 300 000 g/mol. Son degré d'hydrolyse peut être supérieur à 96%, voire supérieur à 99%.Depending on the nature of the solution produced and the nature of the polymer, its molecular weight may be between 5,000 and 300,000 g / mol. Its degree of hydrolysis may be greater than 96%, or even greater than 99%.
Par « agent stabilisant », on entend au sens de la présente invention, un composé permettant une dispersion homogène des nanotubes dans la solution, qui protège les nanotubes de la coagulation en présence de l'homo- ou copolymère d'alcool vinylique, mais qui n'entrave pas la coagulation de l'homo- ou copolymère d'alcool vinylique dans une solution de coagulation.For the purposes of the present invention, the term "stabilizing agent" is intended to mean a compound that allows homogeneous dispersion of the nanotubes in the solution, which protects the nanotubes from coagulation in the presence of the homo- or copolymer of vinyl alcohol, but which does not interfere with the coagulation of the homo- or copolymer of vinyl alcohol in a coagulation solution.
Le ou les agent(s) stabilisant(s) selon l'invention sont liés aux nanotubes soit de façon covalente, soit de façon non covalente.The stabilizing agent (s) according to the invention are bonded to the nanotubes either covalently or non-covalently.
Dans le cas où l'agent stabilisant est lié aux nanotubes de façon non covalente, il pourra être choisi parmi les tensioactifs essentiellement non ioniques.In the case where the stabilizing agent is non-covalently bonded to the nanotubes, it may be chosen from essentially nonionic surfactants.
Par « tensioactif essentiellement non ionique » on entend, au sens de la présente invention, un composé amphiphile non ionique, cité par exemple dans l'ouvrage McCUTCHEON'S 2008 « Emulsifiers and Detergents », et ayant de préférence une HLB (balance hydrophile-lipophile) de 13 à 16, ainsi que les copolymères blocs renfermant des blocs hydrophiles et des blocs lipophiles et présentant une ionicité faible, par exemple 0% à 10% en poids de monomère ionique et 90% à 100% de monomère non ionique.For the purposes of the present invention, the term "essentially nonionic surfactant" is intended to mean a nonionic amphiphilic compound, cited for example in McCutcheon's 2008 "Emulsifiers and Detergents", and preferably having an HLB (hydrophilic-lipophilic balance). from 13 to 16, as well as block copolymers containing hydrophilic blocks and lipophilic blocks and having a low ionicity, for example 0% to 10% by weight of ionic monomer and 90% to 100% of nonionic monomer.
Par exemple dans le cadre de la présente invention, le ou les agent(s) stabilisant(s) lié(s) aux nanotubes de façon non covalente peuvent être choisis parmi :
- (i) les esters de polyols, en particulier :
- les esters d'acide gras et de sorbitane, éventuellement polyéthoxylés, par exemple des tensioactifs de la famille des Tween®,
- les esters d'acides gras et de glycérol,
- les esters d'acides gras et de sucrose,
- les esters d'acides gras et de polyéthylèneglycol,
- (ii) les polysiloxanes modifiés polyéthers,
- (iii) les éthers d'alcools gras et de polyéthylèneglycol, par exemple des tensioactifs de la famille des Brij®,
- (iv) les alkylpolyglycosides,
- (v) les copolymères blocs polyéthylène-polyéthylèneglycol.
- (i) the polyol esters, in particular:
- fatty acid esters of sorbitan, possibly polyethoxylated, for example, surfactants of the family of Tween ®,
- esters of fatty acids and glycerol,
- esters of fatty acids and sucrose,
- esters of fatty acids and of polyethylene glycol,
- (ii) polyether modified polysiloxanes,
- (iii) ethers of fatty alcohols and polyethylene glycol, for example, surfactants of the family of Brij ®,
- (iv) alkylpolyglycosides,
- (v) polyethylene-polyethylene glycol block copolymers.
Dans le second cas où l'agent stabilisant est lié aux nanotubes de façon covalente, il s'agit de préférence d'un groupement hydrophile, avantageusement d'un groupement polyéthylèneglycol greffé sur les nanotubes.In the second case where the stabilizing agent is covalently bonded to the nanotubes, it is preferably a hydrophilic group, preferably a polyethylene glycol group grafted onto the nanotubes.
Le greffage de motifs réactifs tels que des groupements polyéthylèneglycol à la surface des nanotubes peut être réalisé selon tout procédé connu de l'homme du métier. Par exemple, l'homme du métier pourra se rapporter à la publication de
En outre, la dispersion réalisée dans la première étape du procédé selon l'invention comprend un solvant qui est de préférence choisi parmi l'eau, le diméthylsulfoxyde (DMSO), la glycérine, l'éthylène glycol, le diéthylène glycol, le triéthylène glycol, la diéthylène triamine, l'éthylène diamine, le phénol, le diméthylformamide (DMF), le diméthylacétamide, la N-méthylpyrrolidone et leurs mélanges. De manière préférée, le solvant est choisi parmi l'eau, le DMSO et leurs mélanges en toutes proportions.In addition, the dispersion produced in the first step of the process according to the invention comprises a solvent which is preferably chosen from water, dimethylsulfoxide (DMSO), glycerol, ethylene glycol, diethylene glycol and triethylene glycol. , diethylene triamine, ethylene diamine, phenol, dimethylformamide (DMF), dimethylacetamide, N-methylpyrrolidone and mixtures thereof. Preferably, the solvent is chosen from water, DMSO and mixtures thereof in all proportions.
S'il s'agit d'une dispersion aqueuse, le pH de la dispersion aqueuse peut être maintenu de préférence entre 3 et 5 par ajout d'un ou de plusieurs acides, pouvant être choisis parmi les acides inorganiques, tels que l'acide sulfurique, l'acide nitrique et l'acide hydrochlorique, les acides organiques tels que l'acide acétique, l'acide tartrique et l'acide oxalique et les mélanges d'acide organique et de sel d'acide organique tels que l'acide citrique et le citrate de sodium, l'acide acétique et l'acétate de sodium, l'acide tartrique et le tartrate de potassium, l'acide tartrique et le citrate de sodium.If it is an aqueous dispersion, the pH of the aqueous dispersion can be maintained preferably between 3 and 5 by addition of one or more acids, which can be chosen from inorganic acids, such as sulfuric acid, nitric acid and hydrochloric acid, organic acids such as acetic acid, tartaric acid and oxalic acid and mixtures of organic acid and organic acid salt such as acid citric acid and sodium citrate, acetic acid and sodium acetate, tartaric acid and potassium tartrate, tartaric acid and sodium citrate.
D'autre part, la dispersion peut comprendre de l'acide borique, des sels de borate ou leurs mélanges.On the other hand, the dispersion may comprise boric acid, borate salts, or mixtures thereof.
En outre, la dispersion peut aussi comprendre un sel choisi parmi le chlorure de zinc, le thiocyanate de sodium, le chlorure de calcium, le chlorure d'aluminium, le chlorure de lithium, les rhodanates et leurs mélanges. Ils permettent d'optimiser les propriétés rhéologiques de la dispersion et de favoriser la formation de la fibre.In addition, the dispersion may also comprise a salt selected from zinc chloride, sodium thiocyanate, calcium chloride, aluminum chloride, lithium chloride, rhodanates and mixtures thereof. They make it possible to optimize the rheological properties of the dispersion and to promote the formation of the fiber.
Selon une forme avantageuse de la présente invention, la dispersion est réalisée au moyen d'ultrasons ou d'un système rotor-stator ou d'un broyeur à billes. Elle peut être réalisée à température ambiante, ou bien en chauffant, par exemple, entre 40 et 120°C.According to an advantageous form of the present invention, the dispersion is carried out by means of ultrasound or a rotor-stator system or a ball mill. It can be carried out at room temperature, or by heating, for example, between 40 and 120 ° C.
La dispersion ainsi réalisée lors de la première étape du procédé selon l'invention peut comprendre de 2% à 30% en masse d'homo- ou copolymères d'alcool vinylique, de 0,1% à 5% de nanotubes, de 0,1% à 5% d'agent stabilisant, par rapport à la masse totale de la dispersion, solvant compris.The dispersion thus produced during the first step of the process according to the invention may comprise from 2% to 30% by weight of homo- or copolymers of vinyl alcohol, from 0.1% to 5% of nanotubes, from 0.1% to 5% of stabilizing agent, relative to the total mass of the dispersion, including the solvent.
La deuxième étape du procédé consiste à injecter ladite dispersion obtenue lors de la première étape dans une solution de coagulation pour former une pré-fibre, sous forme de mono-filament ou de multi-filaments.The second step of the process consists in injecting said dispersion obtained during the first step into a coagulation solution to form a pre-fiber, in the form of monofilament or multi-filaments.
Par « solution de coagulation », on entend au sens de la présente invention une solution qui provoque la solidification de l'homo- ou copolymère d'alcool vinylique.For the purpose of the present invention, the term "coagulation solution" means a solution which causes the homo- or copolymer of vinyl alcohol to solidify.
De telles solutions sont connues de l'homme du métier, et la production de fibres à base d'homo- ou copolymère d'alcool vinylique fait l'objet d'une littérature riche. De manière générale, les techniques les plus courantes sont le filage au mouillé du PVA, ou « wet spinning » (terminologie anglo-saxonne ; se référer par exemple aux brevets
Selon une forme avantageuse d'exécution de la présente invention, la solution de coagulation comprend un solvant choisi parmi l'eau, un alcool, un polyol, une cétone et leurs mélanges, de manière plus préférée un solvant choisi parmi l'eau, le méthanol, l'éthanol, le butanol, le propanol, l'isopropanol, un glycol, l'acétone, le méthyl-éthyl-cétone, le méthyl-isobutyl-cétone, le benzène, le toluène et leurs mélanges, et de manière encore plus préférée un solvant choisi parmi l'eau, le méthanol, l'éthanol, un glycol, l'acétone et leurs mélanges.According to an advantageous embodiment of the present invention, the coagulation solution comprises a solvent chosen from water, an alcohol, a polyol, a ketone and their mixtures, more preferably a solvent chosen from water, methanol, ethanol, butanol, propanol, isopropanol, glycol, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene and mixtures thereof, and even more preferably a solvent selected from water, methanol, ethanol, a glycol acetone and their mixtures.
Si le solvant de la solution de coagulation est essentiellement de l'eau, la solution de coagulation a de manière avantageuse une température comprise entre 10 et 80°C. Si le solvant de la solution de coagulation est essentiellement organique, tel que le méthanol, la solution de coagulation a de manière avantageuse une température comprise entre -30 et 10°C.If the solvent of the coagulation solution is essentially water, the coagulation solution advantageously has a temperature of between 10 and 80 ° C. If the solvent of the coagulation solution is essentially organic, such as methanol, the coagulation solution advantageously has a temperature between -30 and 10 ° C.
En outre, la solution de coagulation peut comprendre un ou plusieurs sels destinés à favoriser la coagulation de l'homo- ou copolymère d'alcool vinylique, choisis parmi les sels alcalins ou les sels déshydratants tels que le sulfate d'ammonium, le sulfate de potassium, le sulfate de sodium, le carbonate de sodium, l'hydroxyde de sodium, l'hydroxyde de potassium et leurs mélanges.In addition, the coagulation solution may comprise one or more salts intended to promote the coagulation of the homo- or copolymer of vinyl alcohol, chosen from alkaline salts or desiccant salts such as ammonium sulphate, sulphate of potassium, sodium sulfate, sodium carbonate, sodium hydroxide, potassium hydroxide and mixtures thereof.
D'autre part, la solution de coagulation peut comprendre un ou plusieurs composés additionnels qui sont destinés à améliorer les propriétés mécaniques, la résistance à l'eau de la fibre et/ou à faciliter le filage de la fibre. La solution de coagulation peut donc comprendre au moins un composé choisi parmi l'acide borique, les sels de borate et leurs mélanges.On the other hand, the coagulation solution may comprise one or more additional compounds which are intended to improve the mechanical properties, the water resistance of the fiber and / or facilitate the spinning of the fiber. The coagulation solution may therefore comprise at least one compound selected from boric acid, borate salts and mixtures thereof.
De préférence, la solution de coagulation est saturée en sels.Preferably, the coagulation solution is saturated with salts.
De manière avantageuse, la dispersion est injectée lors de la deuxième étape du procédé selon l'invention à travers une ou un ensemble d'aiguilles et/ou une ou un ensemble de buses cylindriques ou coniques non poreuses dans la solution de coagulation, qui peut être statique (bain statique) ou en mouvement (écoulement). La vitesse moyenne d'injection de la dispersion peut être comprise entre 0,1 m/min et 50 m/min, de préférence comprise entre 0,5 m/min et 20 m/min.Advantageously, the dispersion is injected during the second step of the process according to the invention through one or a set of needles and / or one or a set of nonporous cylindrical or conical nozzles into the coagulation solution, which can be static (static bath) or in motion (flow). The average injection speed of the dispersion may be between 0.1 m / min and 50 m / min, preferably between 0.5 m / min and 20 m / min.
La solution coagulante induit la coagulation sous forme d'une pré-fibre par solidification de l'homo- ou copolymère d'alcool vinylique. Les nanotubes se retrouvent piégés dans le polymère qui se solidifie.The coagulant solution induces coagulation in the form of a pre-fiber by solidification of the homo- or copolymer of vinyl alcohol. The nanotubes are trapped in the polymer that solidifies.
L'étape suivante du procédé selon l'invention consiste à extraire, de manière continue ou non, la pré-fibre de la solution de coagulation.The next step of the process according to the invention consists in extracting, continuously or not, the pre-fiber from the coagulation solution.
Après l'extraction de la pré-fibre, celle-ci peut être éventuellement lavée une ou plusieurs fois. Le bac de lavage comprend préférablement de l'eau. L'étape de lavage peut permettre d'éliminer une partie du polymère périphérique de la pré-fibre et ainsi d'enrichir (jusqu'à 70% en poids) la composition de la pré-fibre en nanotubes. En outre, le bain de lavage peut comprendre des agents qui permettent de modifier la composition de la pré-fibre ou qui interagissent chimiquement avec celle-ci. Notamment, des agents de réticulation chimique ou physique, en particulier des sels de borate ou des dialdéhydes, peuvent être ajoutés au bain afin de renforcer la pré-fibre. L'étape de lavage peut aussi permettre d'éliminer les agents, notamment les tensioactifs, potentiellement préjudiciables aux propriétés mécaniques ou électriques de la fibre.After extraction of the pre-fiber, it may be washed once or several times. The wash tank preferably includes water. The washing step can eliminate a portion of the peripheral polymer of the pre-fiber and thus enrich (up to 70% by weight) the composition of the pre-fiber into nanotubes. In addition, the washing bath may comprise agents which make it possible to modify the composition of the pre-fiber or which chemically interact with it. In particular, chemical or physical crosslinking agents, in particular borate salts or dialdehydes, may be added to the bath to reinforce the pre-fiber. The washing step can also make it possible to eliminate the agents, in particular the surfactants, potentially detrimental to the mechanical or electrical properties of the fiber.
Une étape de séchage est également comprise dans le procédé selon l'invention. Cette étape peut avoir lieu soit directement après l'extraction, soit consécutivement au lavage. Notamment, si on souhaite obtenir une fibre enrichie en polymère, il est souhaitable de sécher la pré-fibre directement après l'extraction. Le séchage est de préférence réalisé dans un four qui va sécher la pré-fibre grâce à un gaz circulant dans un conduit intérieur du four. Le séchage peut aussi être réalisé par rayonnement infrarouge.A drying step is also included in the process according to the invention. This step can take place either directly after extraction or after washing. In particular, if it is desired to obtain a polymer-enriched fiber, it is desirable to dry the pre-fiber directly after the extraction. The drying is preferably carried out in an oven that will dry the pre-fiber through a gas flowing in an interior duct of the oven. The drying can also be carried out by infrared radiation.
Le procédé selon l'invention peut également comprendre une étape de bobinage, et éventuellement une étape d'étirage à chaud réalisée entre l'étape de séchage et l'étape de bobinage. Il peut aussi inclure à différents moments des étirements dans des solvants.The method according to the invention may also comprise a winding step, and optionally a hot stretching step performed between the drying step and the winding step. It may also include stretching in solvents at different times.
Cette étape d'étirage peut être effectuée à une température supérieure à la température de transition vitreuse (Tg) de l'homo- ou copolymère d'alcool vinylique et de préférence inférieure à sa température de fusion (si elle existe). Une telle étape, décrite dans le brevet
La présente invention a pour autre objet les fibres composites conductrices susceptibles d'être obtenues selon le procédé de l'invention.Another subject of the present invention is the conductive composite fibers that can be obtained according to the method of the invention.
Lesdites fibres composites conductrices obtenues sont caractérisées par le fait qu'elles renferment de 5 à 70% en poids de nanotubes, de préférence de 5 à 50%, plus préférentiellement de 5 à 30%, et mieux encore de 5 à 25%, par rapport au poids total des fibres. Il est donc possible d'obtenir des fibres composites à haute teneur en nanotubes.Said conductive composite fibers obtained are characterized in that they contain from 5 to 70% by weight of nanotubes, preferably from 5 to 50%, more preferably from 5 to 30%, and more preferably from 5 to 25%, by in relation to the total weight of the fibers. It is therefore possible to obtain composite fibers with a high content of nanotubes.
La fibre obtenue est homogène, ce qui lui confère de bonnes propriétés mécaniques. La fibre peut être caractérisée mécaniquement par un test de traction et elle présente :
- un seuil de rupture mécanique (ou ténacité) de préférence supérieur à 100 MPa, plus préférentiellement supérieur à 300 MPa, et mieux encore supérieur à 500 MPa ;
- un allongement à la rupture de préférence compris entre 0,1 et 500% d'étirement, plus préférentiellement entre 1 et 400% d'étirement, et mieux encore entre 3 et 400% d'étirement ; et
- un module d'Young (ou module de traction) compris de préférence entre 1 et 100 GPa, de préférence entre 2 et 60 GPa.
- a mechanical rupture threshold (or toughness) preferably greater than 100 MPa, more preferably greater than 300 MPa, and more preferably greater than 500 MPa;
- an elongation at break preferably between 0.1 and 500% stretching, more preferably between 1 and 400% stretching, and more preferably between 3 and 400% stretching; and
- a Young's modulus (or traction modulus) preferably comprised between 1 and 100 GPa, preferably between 2 and 60 GPa.
En outre, les fibres composites conductrices obtenues selon ce procédé présentent une résistivité qui peut être comprise entre 10-3 et 105 ohm.cm à température ambiante. Cette conductivité électrique peut encore être améliorée par des traitements thermiques.In addition, the conductive composite fibers obtained according to this process have a resistivity which can be between 10 -3 and 10 5 ohm.cm at room temperature. This electrical conductivity can be further improved by heat treatments.
La présente invention a aussi pour objet les fibres composites conductrices comprenant :
- de 5 à 70% en poids, par rapport au poids total des fibres, de nanotubes capables d'assurer une conduction thermique et/ou électrique et constitués d'au moins un élément chimique choisi parmi les éléments des colonnes IIIa, IVa et Va du tableau périodique,
- un homo- ou copolymère d'alcool vinylique, et
- au moins un agent stabilisant, lié de façon non covalente aux nanotubes, choisi parmi les tensioactifs essentiellement non ioniques ayant une HLB de 13 à 16.
- from 5 to 70% by weight, relative to the total weight of the fibers, of nanotubes capable of providing thermal and / or electrical conduction and consisting of at least one chemical element chosen from the elements of columns IIIa, IVa and Va of periodic table,
- a homo- or copolymer of vinyl alcohol, and
- at least one stabilizing agent, non-covalently bonded to the nanotubes, selected from substantially nonionic surfactants having a HLB of 13 to 16.
Enfin, la présente invention a pour objet l'utilisation des fibres composites conductrices selon l'invention pour les applications suivante :
- pour la fabrication de nez, d'ailes ou de carlingues de fusées ou d'avions ;
- pour la fabrication d'armures de flexible off-shore ;
- pour la fabrication d'éléments de carrosserie automobile, de châssis moteur ou de pièces support pour l'automobile ;
- pour la fabrication de revêtements de sièges automobiles ;
- pour la fabrication d'éléments de charpentes dans le domaine du bâtiment ou des ponts et chaussées ;
- pour la fabrication d'emballages et de textiles antistatiques, notamment de rideaux antistatiques, de vêtements antistatiques (par exemple, de sécurité ou pour salle blanche) ou de matériaux pour la protection de silos ou le conditionnement et/ou le transport de poudres ou de matériaux granulaires ;
- pour la fabrication d'éléments d'ameublement, notamment de mobilier pour salle blanche ;
- pour la fabrication de filtres ;
- pour la fabrication de dispositifs de blindage électromagnétique, notamment pour la protection de composants électroniques ;
- pour la fabrication de textiles chauffants ;
- pour la fabrication de câbles conducteurs ;
- pour la fabrication de capteurs, notamment de capteurs de déformation ou de contraintes mécaniques ;
- pour la fabrication d'électrodes ;
- pour la fabrication de dispositifs de stockage d'hydrogène ; ou de dispositifs biomédicaux tels que des fils de suture, des prothèses ou des cathéters.
- for the manufacture of nose, wings or cabins of rockets or airplanes;
- for the manufacture of off-shore flexible armor;
- for the manufacture of automobile bodywork components, engine chassis or automobile support parts;
- for the manufacture of car seat coverings;
- for the manufacture of structural elements in the field of buildings or bridges and roadways;
- for the manufacture of antistatic packaging and textiles, including antistatic curtains, antistatic clothing (eg safety or clean room) or materials for the protection of silos or the packaging and / or transport of powders or granular materials;
- for the manufacture of furniture items, including clean room furniture;
- for the manufacture of filters;
- for the manufacture of electromagnetic shielding devices, in particular for the protection of electronic components;
- for the manufacture of heating textiles;
- for the manufacture of conductive cables;
- for the manufacture of sensors, in particular deformation sensors or mechanical stresses;
- for the manufacture of electrodes;
- for the manufacture of hydrogen storage devices; or biomedical devices such as sutures, prostheses or catheters.
La fabrication de ces pièces composites peut être réalisée suivant différents procédés, impliquant en général une étape d'imprégnation des fibres composites conductrices selon l'invention par une composition polymérique renfermant au moins un matériau thermoplastique, élastomère ou thermodurcissable. Cette étape d'imprégnation peut elle-même être effectuée suivant différentes techniques, en fonction notamment de la forme physique de la composition polymérique utilisée (pulvérulente ou plus ou moins liquide). L'imprégnation des fibres composites conductrices est de préférence réalisée suivant un procédé d'imprégnation en lit fluidisé, dans lequel la composition polymérique se trouve à l'état de poudre. Des fibres pré-imprégnées sont ainsi obtenues.The manufacture of these composite parts can be carried out according to various processes, generally involving a step of impregnating the composite fibers. conductive according to the invention by a polymeric composition containing at least one thermoplastic material, elastomeric or thermosetting. This impregnation step may itself be carried out according to various techniques, depending in particular on the physical form of the polymeric composition used (pulverulent or more or less liquid). The impregnation of the conductive composite fibers is preferably carried out according to a fluidized bed impregnation process, in which the polymeric composition is in the form of powder. Pre-impregnated fibers are thus obtained.
On obtient ainsi des semi-produits qui sont ensuite utilisés dans la fabrication de la pièce composite recherchée. Différents tissus de fibres pré-imprégnées, de composition identique ou différente, peuvent être empilés pour former une plaque ou un matériau stratifié, ou en variante soumis à un procédé de thermoformage. En variante, les fibres pré-imprégnées peuvent être associées pour former des rubans qui sont susceptibles d'être utilisés dans un procédé d'enroulement filamentaire permettant l'obtention de pièces creuses de forme quasi-illimitée, par enroulement des rubans sur un mandrin ayant la forme de la pièce à fabriquer. Dans tous les cas, la fabrication de la pièce finie comprend une étape de consolidation de la composition polymérique, qui est par exemple fondue localement pour créer des zones de fixation des fibres pré-imprégnées entre elles et/ou solidariser les rubans de fibres pré-imprégnées dans le procédé d'enroulement filamentaire.Semi-finished products are thus obtained which are then used in the manufacture of the desired composite part. Different preimpregnated fiber fabrics, of identical or different composition, can be stacked to form a plate or a laminated material, or alternatively subjected to a thermoforming process. As a variant, the pre-impregnated fibers may be combined to form ribbons which may be used in a filament winding process which makes it possible to obtain hollow pieces of almost unlimited shape, by winding the ribbons on a mandrel having the shape of the part to be made. In all cases, the manufacture of the finished part comprises a step of consolidating the polymeric composition, which is for example melted locally to create zones for fixing the fibers pre-impregnated with each other and / or to secure the fiber ribbons pre-impregnated with each other. impregnated in the filament winding process.
En variante encore, il est possible de préparer un film à partir de la composition polymérique d'imprégnation, notamment au moyen d'un procédé d'extrusion ou de calandrage, ledit film ayant par exemple une épaisseur d'environ 100 µm, puis de le placer entre deux mats de fibres composites conductrices selon l'invention, l'ensemble étant alors pressé à chaud pour permettre l'imprégnation des fibres et la fabrication de la pièce composite.In another variant, it is possible to prepare a film from the polymeric impregnating composition, in particular by means of an extrusion or calendering process, said film having for example a thickness of about 100 μm, then of placing it between two conductive composite fiber mats according to the invention, the assembly then being hot pressed to allow the impregnation of the fibers and the manufacture of the composite part.
Dans ces procédés, les fibres composites conductrices selon l'invention peuvent être tissées ou tricotées, seules ou avec d'autres fibres, ou être utilisées, seules ou en association avec d'autres fibres, pour la fabrication de feutres ou de matériaux non-tissés. Des exemples de matériaux constitutifs de ces autres fibres comprennent, sans limitation :
- les fibres de polymère étiré, à base notamment : de polyamide tel que le polyamide 6 (PA-6), le polyamide 11 (PA-11), le polyamide 12 (PA-12), le polyamide 6.6 (PA-6.6), le polyamide 4.6 (PA-4.6), le polyamide 6.10 (PA-6.10) ou le polyamide 6.12 (PA-6.12), de copolymère bloc polyamide/polyéther (Pebax®), de polyéthylène haute densité, de polypropylène ou de polyester tel que les polyhydroxyalcanoates et les polyesters commercialisés par DU PONT sous la dénomination commerciale Hytrel® ;
- les fibres de carbone ;
- les fibres de verre, notamment de type E, R ou S2 ;
- les fibres d'aramide (Kevlar®) ;
- les fibres de bore ;
- les fibres de silice ;
- les fibres naturelles telles que le lin, le chanvre, le sisal le coton ou la laine ; et
- leurs mélanges, tels que les mélanges de fibres de verre, carbone et aramide.
- stretched polymer fibers, based in particular on: polyamide such as polyamide 6 (PA-6), polyamide 11 (PA-11), polyamide 12 (PA-12), polyamide 6.6 (PA-6.6), polyamide 4.6 (PA-4,6), polyamide-6,10 (PA-6.10) or polyamide 6.12 (PA-6.12), copolymer polyamide / polyether block (Pebax ®), high density polyethylene, polypropylene or polyester such as polyhydroxyalkanoates and polyesters marketed by Du Pont under the trade name Hytrel ®;
- carbon fibers;
- glass fibers, especially of type E, R or S2;
- aramid fibers (Kevlar ® );
- boron fibers;
- silica fibers;
- natural fibers such as linen, hemp, sisal, cotton or wool; and
- mixtures thereof, such as fiberglass, carbon and aramid blends.
La présente invention a ainsi pour autre objet les matériaux composites comprenant des fibres composites conductrices selon l'invention, liées entre elles par tissage ou par une composition polymérique.The present invention thus has for another object composite materials comprising conductive composite fibers according to the invention, bonded together by weaving or by a polymeric composition.
D'autres caractéristiques et avantages de l'invention apparaîtront à la lecture des exemples non limitatifs et purement illustratifs qui vont suivre.Other characteristics and advantages of the invention will appear on reading the nonlimiting and purely illustrative examples which follow.
0,5% en masse de nanotubes de carbone monoparoi et 1% de Brij®78 ont été dispersés dans de l'eau. Cette dispersion a ensuite été homogénéisée par une sonde à ultrasons réglée à la puissance de 20 W.0.5% by weight of single-walled carbon nanotubes and 1% of Brij®78 were dispersed in water. This dispersion was then homogenized by an ultrasonic probe set at the power of 20 W.
Une solution aqueuse de poly(alcool vinylique) (PVA) à 8% en masse, de masse moléculaire 195 000 g/mol et de degrés d'hydrolyse de 98% a été ajoutée. La dispersion ainsi obtenue, constituée de 0,25% en masse de nanotubes monoparois, 0,5% de Brij®78 et 4% de PVA dans de l'eau, a été homogénéisée par agitation magnétique.An aqueous solution of polyvinyl alcohol (PVA) at 8% by weight, molecular weight 195,000 g / mol and degrees of hydrolysis of 98% was added. The dispersion thus obtained, consisting of 0.25% by weight of single-walled nanotubes, 0.5% of Brij®78 and 4% of PVA in water, was homogenized by magnetic stirring.
La dispersion a été alors injectée dans un bain statique d'une solution coagulante de sulfate de sodium saturée (320 g/L) à 40°C.The dispersion was then injected into a static bath of a saturated sodium sulfate coagulant solution (320 g / L) at 40 ° C.
La pré-fibre a été extraite du bain de coagulation après un temps de résidence inférieur à dix secondes. Elle a été ensuite séchée par rayonnement infra rouge, puis redirigée dans un bain de lavage contenant de l'eau. Après 1 min, elle a été séchée à nouveau par rayonnement infra rouge puis bobinée.The pre-fiber was extracted from the coagulation bath after a residence time of less than ten seconds. It was then dried by infra-red radiation, then redirected into a washing bath containing water. After 1 min, it was dried again by infrared radiation and then wound.
La fibre finale obtenue contient 8% de nanotubes en masse. Cette valeur a été obtenue par analyse thermogravimétrique (ATG). Le cliché de microscopie à balayage présenté
La fibre est cylindrique et homogène et elle a été caractérisée mécaniquement par traction. Elle possède une énergie de rupture de 475 J/g, un allongement à la rupture de 425% d'étirement et un module d'Young de 3 GPa. Après un étirement à chaud à 200°C de 400%, son module d'Young augmente jusqu'à 29 GPa et son seuil de rupture passe à 12% d'étirement.The fiber is cylindrical and homogeneous and has been mechanically characterized by traction. It has a breaking energy of 475 J / g, an elongation at break of 425% stretching and a Young's modulus of 3 GPa. After hot stretching at 200 ° C of 400%, its Young's modulus increases to 29 GPa and its rupture threshold increases to 12% stretching.
Des fibres composites ont été réalisées en partant de dispersions aqueuses de nanotubes multiparois. 0,9% en masse de nanotubes et 1,2% de Brij®78 ont été dispersés dans de l'eau. Par le même procédé que décrit dans l'exemple 1, des fibres chargées à 17% en nanotubes multiparois ont été obtenues.Composite fibers were made starting from aqueous dispersions of multiwall nanotubes. 0.9% by weight of nanotubes and 1.2% Brij®78 were dispersed in water. By the same method as described in Example 1, fibers loaded with 17% multiwall nanotubes were obtained.
Ces fibres présentent l'avantage de combiner de bonnes propriétés mécaniques avec des propriétés électriques tout à fait intéressantes, puisqu'elles sont conductrices de l'électricité, avec une résistivité de 10 Ω.cm. Elles présentent une ténacité de 340 MPa, un module d'Young de 5,5 GPa et un allongement à la rupture de 240%.These fibers have the advantage of combining good mechanical properties with quite interesting electrical properties, since they are electrically conductive, with a resistivity of 10 Ω.cm. They have a toughness of 340 MPa, a Young's modulus of 5.5 GPa and an elongation at break of 240%.
0,9% en masse de nanotubes de carbone multiparoi et 1,2% de Brij®78 ont été dispersés dans de l'eau. Le mélange a été ensuite homogénéisé par une sonde à ultrasons réglée à la puissance de 20 W.0.9% by weight of multi-walled carbon nanotubes and 1.2% of Brij®78 were dispersed in water. The mixture was then homogenized by an ultrasound probe set at the power of 20 W.
On a ensuite ajouté à cette dispersion une solution aqueuse de PVA à 16% en masse, de masse moléculaire 61 000 g/mol et de degrés d'hydrolyse de 98%. La dispersion ainsi obtenue a été homogénéisée par agitation magnétique. On a ajouté à cette dispersion de l'acide borique à hauteur de 0,5% en masse par rapport au PVA, et le pH a été amené à une valeur inférieure à 5 par ajout d'acide nitrique dilué. On a ainsi obtenu une dispersion constituée de 0,45% en masse de nanotubes monoparois, 0,6% de Brij®78 et 8% de PVA dans de l'eau.To this dispersion was then added an aqueous PVA solution at 16% by weight, with a molecular weight of 61,000 g / mol and with a degree of hydrolysis of 98%. The dispersion thus obtained was homogenized by magnetic stirring. Boric acid was added to this dispersion at a level of 0.5% by weight relative to PVA, and the pH was brought to a value of less than 5 by adding dilute nitric acid. There was thus obtained a dispersion consisting of 0.45% by weight of single-walled nanotubes, 0.6% of Brij®78 and 8% of PVA in water.
La solution a ensuite été injectée dans un bain statique d'une solution coagulante de sulfate de sodium saturée (320 g/L) à 40°C pour former une fibre.The solution was then injected into a static bath of a saturated sodium sulfate coagulant solution (320 g / L) at 40 ° C to form a fiber.
La fibre finale obtenue contient 12% de nanotubes en masse. Elle présente une ténacité de 360 MPa, un module d'Young de 4 GPa et un allongement à la rupture de 325%, ainsi qu'une résistivité de 30 Ω.cm.The final fiber obtained contains 12% of nanotubes in mass. It has a toughness of 360 MPa, a Young's modulus of 4 GPa and an elongation at break of 325%, as well as a resistivity of 30 Ω.cm.
La dispersion décrite dans l'exemple 3 a été injectée dans un bain coagulant contenant de l'hydroxyde de sodium (50 g/L) et du sulfate de sodium (300 g/L) à 40°C.The dispersion described in Example 3 was injected into a coagulant bath containing sodium hydroxide (50 g / L) and sodium sulfate (300 g / L) at 40 ° C.
La fibre finale obtenue contient 12% de nanotubes en masse. Elle présente une ténacité de 320 MPa, un module d'Young de 7 GPa et un allongement à la rupture de 200%, ainsi qu'une résistivité de 100 Ω.cm.The final fiber obtained contains 12% of nanotubes in mass. It has a toughness of 320 MPa, a Young's modulus of 7 GPa and an elongation at break of 200%, as well as a resistivity of 100 Ω.cm.
0,5% en masse de nanotubes de carbone monoparoi et 1% de Brij®78 ont été dispersés dans un mélange eau/DMSO comprenant la même fraction massique de chaque solvant.0.5% by weight of single-walled carbon nanotubes and 1% Brij®78 were dispersed in a water / DMSO mixture comprising the same mass fraction of each solvent.
On a ensuite ajouté à cette dispersion une solution de PVA à 16% en masse dans un mélange eau/DMSO, de masse moléculaire 61 000 g/mol et de degrés d'hydrolyse de 98%. La dispersion ainsi obtenue, constituée de 0,25% en masse de nanotubes monoparois, 0,5% de Brij®78 et 8% de PVA, a été homogénéisée par agitation magnétique.A solution of PVA at 16% by weight in a water / DMSO mixture, with a molecular weight of 61,000 g / mol and a degree of hydrolysis of 98%, was then added to this dispersion. The dispersion thus obtained, consisting of 0.25% by weight of single-walled nanotubes, 0.5% Brij®78 and 8% PVA, was homogenized by magnetic stirring.
La dispersion a été alors injectée dans un bain coagulant de méthanol à -20°C contenant 10% de DMSO pour former des fibres chargées à 8% en nanotubes.The dispersion was then injected into a methanol coagulant bath at -20 ° C containing 10% DMSO to form 8% nanotube filled fibers.
Claims (17)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0953508A FR2946177B1 (en) | 2009-05-27 | 2009-05-27 | PROCESS FOR MANUFACTURING CONDUCTIVE COMPOSITE FIBERS HAVING HIGH NANOTUBE CONTENT. |
Publications (1)
Publication Number | Publication Date |
---|---|
EP2256236A1 true EP2256236A1 (en) | 2010-12-01 |
Family
ID=41396371
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP10163360A Withdrawn EP2256236A1 (en) | 2009-05-27 | 2010-05-20 | Method for manufacturing conducting composite fibres with high nanotube content |
Country Status (7)
Country | Link |
---|---|
US (1) | US20110017957A1 (en) |
EP (1) | EP2256236A1 (en) |
JP (1) | JP2010281024A (en) |
CN (1) | CN101899723A (en) |
FR (1) | FR2946177B1 (en) |
TW (1) | TW201111569A (en) |
WO (1) | WO2010136704A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012160288A1 (en) | 2011-05-23 | 2012-11-29 | Arkema France | Conductive composite fibres comprising carbon-based conductive fillers and a conductive polymer |
WO2013011250A1 (en) * | 2011-07-21 | 2013-01-24 | Arkema France | Graphene-based conductive composite fibres |
FR2983850A1 (en) * | 2011-12-09 | 2013-06-14 | Commissariat Energie Atomique | Preparing crude fiber comprising mixture of ceramic powder and polymer, comprises injecting suspension comprising ceramic powder of identical nature and polymer capable to coagulate in presence of liquid coagulant, in liquid solution |
CN105297239A (en) * | 2015-09-17 | 2016-02-03 | 无锡市长安曙光手套厂 | Fragrance-releasing fabric and preparation method for same |
CN109502570A (en) * | 2018-12-14 | 2019-03-22 | 郑州大学 | Conductive big strain carbon nano-tube coextruded film, preparation method and test method |
Families Citing this family (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010135335A1 (en) * | 2009-05-18 | 2010-11-25 | Ppg Industries Ohio, Inc. | Aqueous dispersions, conductive fiber glass strands, and composites comprising the same |
KR101182380B1 (en) | 2011-03-15 | 2012-09-12 | 한양대학교 산학협력단 | Hybrid polymer composite fibers comprising graphene and carbon nanotubes |
WO2013034672A2 (en) * | 2011-09-07 | 2013-03-14 | Teijin Aramid B.V. | Carbon nanotubes fiber having low resistivity |
JP5919018B2 (en) * | 2012-02-13 | 2016-05-18 | ニッタ株式会社 | Vinylon fiber containing carbon nanotube and method for producing the same |
US8739743B2 (en) * | 2012-03-27 | 2014-06-03 | Go Green Hybrid Fuel Systems | Hydrogen feed method and systems for engines |
FR2998573B1 (en) * | 2012-11-26 | 2015-09-04 | Arkema France | MASTER MIXTURE BASED ON CARBON NANOCHARGES AND SUPERPLASTIFIANT, AND ITS USE IN INORGANIC CURABLE SYSTEMS |
KR101946318B1 (en) | 2013-06-19 | 2019-02-11 | 코오롱인더스트리 주식회사 | Method of manufacturing copolymerized aramid fiber and copolymerized aramid fiber manufactured thereby |
FR3007412B1 (en) * | 2013-06-20 | 2015-07-17 | Centre Nat Rech Scient | PROCESS FOR RECOVERING ORGANIC FIBERS FROM A COMPOSITE MATERIAL |
FR3019563B1 (en) * | 2014-04-03 | 2016-04-29 | Centre Nat Rech Scient | PROCESS FOR PREPARING MACROSCOPIC FIBERS OF TITANIUM DIOXIDE BY CONTINUOUS UNIDIRECTIONAL EXTRUSION, FIBERS OBTAINED AND APPLICATIONS |
JP6442160B2 (en) * | 2014-05-09 | 2018-12-19 | 日本ゼオン株式会社 | Method for producing carbon nanotube composite material |
CN104940989A (en) * | 2015-06-24 | 2015-09-30 | 苏州乔纳森新材料科技有限公司 | Absorbable suture line and method for preparing the same |
CN105220455A (en) * | 2015-09-17 | 2016-01-06 | 无锡市长安曙光手套厂 | A kind of fragrant citrus taste releases fragrant fabric and preparation method thereof |
CN105133312A (en) * | 2015-09-17 | 2015-12-09 | 无锡市长安曙光手套厂 | Fabric capable of repelling mosquitoes and preparation method thereof |
WO2017106484A1 (en) * | 2015-12-15 | 2017-06-22 | Agc Chemicals Americas Inc. | A layered tube and layer for use in same |
CN107299444A (en) * | 2017-06-29 | 2017-10-27 | 顾渊 | One kind releases fragrant fabric and preparation method thereof |
US11365493B2 (en) | 2017-11-06 | 2022-06-21 | King Abdullah University Of Science And Technology | Method for making copolymer-wrapped nanotube fibers |
RU2708583C1 (en) * | 2019-04-12 | 2019-12-09 | МСД Текнолоджис С.а.р.л. | Method of producing high-strength composite material based on a thermoplastic polymer, a modifier for preparing a composite material and a method of producing a modifier for preparing composite material (versions) |
TWI715381B (en) * | 2019-12-27 | 2021-01-01 | 穩得實業股份有限公司 | Fiber-grade conductive polymer composition and multifilament fiber yarn |
CN113186656A (en) * | 2021-04-29 | 2021-07-30 | 北京石油化工学院 | Carbon nitride-polyvinyl alcohol composite antibacterial film and preparation method and application thereof |
KR102652781B1 (en) * | 2021-11-01 | 2024-03-29 | 한국생산기술연구원 | Conductive fiber containing carbon material and method for preparing the same |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3850901A (en) | 1969-11-25 | 1974-11-26 | T Kimura | Polyvinyl alcohol fibers |
US3852402A (en) | 1969-11-25 | 1974-12-03 | S Tanaka | Process for the preparation of polyvinyl alcohol fibers |
WO1986003455A1 (en) | 1984-12-06 | 1986-06-19 | Hyperion Catalysis International, Inc. | Carbon fibrils, method for producing same, and compositions containing same |
US4603083A (en) | 1983-12-12 | 1986-07-29 | Toray Industries, Inc. | Ultra-high-tenacity polyvinyl alcohol fiber and process for producing same |
US4612157A (en) | 1984-01-31 | 1986-09-16 | Kuraray Company, Limited | Method for production of high-tenacity, fine-denier polyvinyl alcohol fiber |
EP0395048A2 (en) * | 1989-04-27 | 1990-10-31 | Kuraray Co., Ltd. | Synthetic polyvinyl alcohol fiber and process for its production |
US4971861A (en) | 1986-12-27 | 1990-11-20 | Unitika Ltd. | Polyvinyl alcohol fiber and method of manufacture thereof |
US5208104A (en) | 1988-02-10 | 1993-05-04 | Toray Industries, Inc. | High-tenacity water-soluble polyvinyl alcohol fiber and process for producing the same |
WO2000053833A1 (en) * | 1999-03-08 | 2000-09-14 | Ostthüringische Materialprüfgesellschaft Für Textil Und Kunststoffe Mbh | Method for producing shaped bodies |
WO2000069958A1 (en) | 1999-05-18 | 2000-11-23 | Atofina Research | Reinforced polymers |
FR2805179A1 (en) | 2000-02-23 | 2001-08-24 | Centre Nat Rech Scient | PROCESS FOR OBTAINING FIBERS AND MACROSCOPIC TAPES FROM COLLOIDAL PARTICLES, IN PARTICULAR CARBON NANOTUBES |
WO2005061763A1 (en) * | 2003-12-18 | 2005-07-07 | The Procter & Gamble Company | Rotary spinning processes for forming hydroxyl polymer-containing fibers |
US7026049B2 (en) | 2004-02-18 | 2006-04-11 | Kuraray Co., Ltd. | Conductive polyvinyl alcohol fiber |
FR2921075A1 (en) | 2007-09-18 | 2009-03-20 | Arkema France | CONTINUOUS PROCESS FOR OBTAINING COMPOSITE FIBERS BASED ON COLLOIDAL PARTICLES AND DEVICE FOR IMPLEMENTING SAID METHOD |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IL142254A0 (en) * | 2001-03-26 | 2002-03-10 | Univ Ben Gurion | Method for the preparation of stable suspensions of single carbon nanotubes |
AU2003238250B2 (en) * | 2002-06-14 | 2009-06-11 | Hyperion Catalysis International, Inc. | Electroconductive carbon fibril-based inks and coatings |
WO2004024428A1 (en) * | 2002-09-10 | 2004-03-25 | The Trustees Of The University Pennsylvania | Carbon nanotubes: high solids dispersions and nematic gels thereof |
CN101905879B (en) * | 2004-07-27 | 2012-05-30 | 帝斯曼知识产权资产管理有限公司 | Process for making a carbon nanotubes / ultra-high molar mass polyethylene composite fibre |
DE602005010747D1 (en) * | 2005-01-13 | 2008-12-11 | Cinv Ag | CARBON NANOPARTICLES CONTAINING COMPOSITE MATERIALS |
US7462656B2 (en) * | 2005-02-15 | 2008-12-09 | Sabic Innovative Plastics Ip B.V. | Electrically conductive compositions and method of manufacture thereof |
US20070099792A1 (en) * | 2005-04-27 | 2007-05-03 | William Marsh Rice University | Carbon nanotube reinforced thermoplastic polymer composites achieved through benzoyl peroxide initiated interfacial bonding to polymer matrices |
US20100078194A1 (en) * | 2005-08-08 | 2010-04-01 | Sandeep Bhatt | Polymeric compositions containing nanotubes |
EP1962348B1 (en) * | 2005-08-12 | 2013-03-06 | Cambrios Technologies Corporation | Nanowires-based transparent conductors |
EP1845124A1 (en) * | 2006-04-14 | 2007-10-17 | Arkema France | Conductive carbon nanotube-polymer composite |
WO2009119563A1 (en) * | 2008-03-25 | 2009-10-01 | 東レ株式会社 | Electrically conductive complex and process for production thereof |
WO2010002896A1 (en) * | 2008-07-01 | 2010-01-07 | Vorbeck Materials Corp. | Articles having a compositional gradient and methods for their manufacture |
CN106479239A (en) * | 2008-12-19 | 2017-03-08 | 沃尔贝克材料有限公司 | Comprise ink and the coating of multichain lipid |
-
2009
- 2009-05-27 FR FR0953508A patent/FR2946177B1/en not_active Expired - Fee Related
-
2010
- 2010-05-20 EP EP10163360A patent/EP2256236A1/en not_active Withdrawn
- 2010-05-20 WO PCT/FR2010/050981 patent/WO2010136704A1/en active Application Filing
- 2010-05-24 TW TW099116530A patent/TW201111569A/en unknown
- 2010-05-25 JP JP2010119151A patent/JP2010281024A/en not_active Abandoned
- 2010-05-26 US US12/787,917 patent/US20110017957A1/en not_active Abandoned
- 2010-05-27 CN CN2010102239220A patent/CN101899723A/en active Pending
Patent Citations (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3852402A (en) | 1969-11-25 | 1974-12-03 | S Tanaka | Process for the preparation of polyvinyl alcohol fibers |
US3850901A (en) | 1969-11-25 | 1974-11-26 | T Kimura | Polyvinyl alcohol fibers |
US4603083A (en) | 1983-12-12 | 1986-07-29 | Toray Industries, Inc. | Ultra-high-tenacity polyvinyl alcohol fiber and process for producing same |
US4698194A (en) | 1983-12-12 | 1987-10-06 | Toray Industries, Inc. | Process for producing ultra-high-tenacity polyvinyl alcohol fiber |
US4612157A (en) | 1984-01-31 | 1986-09-16 | Kuraray Company, Limited | Method for production of high-tenacity, fine-denier polyvinyl alcohol fiber |
WO1986003455A1 (en) | 1984-12-06 | 1986-06-19 | Hyperion Catalysis International, Inc. | Carbon fibrils, method for producing same, and compositions containing same |
US4971861A (en) | 1986-12-27 | 1990-11-20 | Unitika Ltd. | Polyvinyl alcohol fiber and method of manufacture thereof |
US5208104A (en) | 1988-02-10 | 1993-05-04 | Toray Industries, Inc. | High-tenacity water-soluble polyvinyl alcohol fiber and process for producing the same |
EP0395048A2 (en) * | 1989-04-27 | 1990-10-31 | Kuraray Co., Ltd. | Synthetic polyvinyl alcohol fiber and process for its production |
WO2000053833A1 (en) * | 1999-03-08 | 2000-09-14 | Ostthüringische Materialprüfgesellschaft Für Textil Und Kunststoffe Mbh | Method for producing shaped bodies |
WO2000069958A1 (en) | 1999-05-18 | 2000-11-23 | Atofina Research | Reinforced polymers |
US6331265B1 (en) | 1999-05-18 | 2001-12-18 | Atofina Research | Reinforced polymers |
FR2805179A1 (en) | 2000-02-23 | 2001-08-24 | Centre Nat Rech Scient | PROCESS FOR OBTAINING FIBERS AND MACROSCOPIC TAPES FROM COLLOIDAL PARTICLES, IN PARTICULAR CARBON NANOTUBES |
WO2005061763A1 (en) * | 2003-12-18 | 2005-07-07 | The Procter & Gamble Company | Rotary spinning processes for forming hydroxyl polymer-containing fibers |
US7026049B2 (en) | 2004-02-18 | 2006-04-11 | Kuraray Co., Ltd. | Conductive polyvinyl alcohol fiber |
FR2921075A1 (en) | 2007-09-18 | 2009-03-20 | Arkema France | CONTINUOUS PROCESS FOR OBTAINING COMPOSITE FIBERS BASED ON COLLOIDAL PARTICLES AND DEVICE FOR IMPLEMENTING SAID METHOD |
Non-Patent Citations (5)
Title |
---|
B. ZHAO ET AL.: "Synthesis and Characterization of Water Soluble Single-Walled Carbon Nanotube Graft Copolymers", J. AM. CHEM. SOC., vol. 127, no. 22, 2005 |
XUE ET AL.: "Electrically conductive yarns based on PVA/carbon nanotubes", COMPOSITE STRUCTURES, vol. 78, 2007, pages 271 - 277 |
XUE ET AL: "Electrically conductive yarns based on PVA/carbon nanotubes", COMPOSITE STRUCTURES, ELSEVIER SCIENCE LTD, GB, vol. 78, no. 2, 8 December 2006 (2006-12-08), pages 271 - 277, XP005798860, ISSN: 0263-8223 * |
ZHANG ET AL.: "Gel spinning of PVA/SWNT composite fiber", POLYMER, vol. 45, 2004, pages 8801 - 8807 |
ZHANG X ET AL: "Gel spinning of PVA/SWNT composite fiber", POLYMER, ELSEVIER SCIENCE PUBLISHERS B.V, GB, vol. 45, no. 26, 1 December 2004 (2004-12-01), pages 8801 - 8807, XP004652167, ISSN: 0032-3861 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012160288A1 (en) | 2011-05-23 | 2012-11-29 | Arkema France | Conductive composite fibres comprising carbon-based conductive fillers and a conductive polymer |
WO2013011250A1 (en) * | 2011-07-21 | 2013-01-24 | Arkema France | Graphene-based conductive composite fibres |
FR2983850A1 (en) * | 2011-12-09 | 2013-06-14 | Commissariat Energie Atomique | Preparing crude fiber comprising mixture of ceramic powder and polymer, comprises injecting suspension comprising ceramic powder of identical nature and polymer capable to coagulate in presence of liquid coagulant, in liquid solution |
CN105297239A (en) * | 2015-09-17 | 2016-02-03 | 无锡市长安曙光手套厂 | Fragrance-releasing fabric and preparation method for same |
CN109502570A (en) * | 2018-12-14 | 2019-03-22 | 郑州大学 | Conductive big strain carbon nano-tube coextruded film, preparation method and test method |
Also Published As
Publication number | Publication date |
---|---|
US20110017957A1 (en) | 2011-01-27 |
FR2946177A1 (en) | 2010-12-03 |
WO2010136704A1 (en) | 2010-12-02 |
TW201111569A (en) | 2011-04-01 |
CN101899723A (en) | 2010-12-01 |
FR2946177B1 (en) | 2011-05-27 |
JP2010281024A (en) | 2010-12-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2256236A1 (en) | Method for manufacturing conducting composite fibres with high nanotube content | |
EP2370619B1 (en) | Pekk composite fibre, its method of production, and its uses | |
FR2946176A1 (en) | MULTILAYER CONDUCTIVE FIBER AND PROCESS FOR OBTAINING IT BY CO-EXTRUSION | |
FR2946178A1 (en) | PROCESS FOR MANUFACTURING COATED MULTILAYER CONDUCTIVE FIBER | |
EP2160275B1 (en) | Method for impregnating continuous fibres with a composite polymer matrix containing a grafted fluorinated polymer | |
WO2013011250A1 (en) | Graphene-based conductive composite fibres | |
EP3728711A1 (en) | Method for producing a carbon fibre from recycled cotton and use of the fibre obtained in this way for forming an article made from composite material | |
FR2918081A1 (en) | METHOD FOR IMPREGNATING FIBERS CONTINUOUS BY A COMPOSITE POLYMERIC MATRIX COMPRISING A THERMOPLASTIC POLYMER | |
WO2009047456A2 (en) | Continuous method for obtaining composite fibres containing colloidal particles and resulting fibre | |
EP2909366A1 (en) | Method for manufacturing a carbon fibre, precursor material used by the method and carbon fibre obtained | |
KR101406597B1 (en) | Method for Preparing Graphene-Polymer Composite Powder and Fiber | |
CA3039721A1 (en) | Novel method for producing high-carbon materials and high-carbon material produced | |
CA2644518C (en) | Method for making polymeric extruded composite products and carbon nanotubes | |
WO2012160288A1 (en) | Conductive composite fibres comprising carbon-based conductive fillers and a conductive polymer | |
WO2019086377A2 (en) | Preparation of carbon fibers from lignin/pva precursor fibers | |
Ranjan et al. | Multi-walled carbon nanotube/polymer composite: a nano-enabled continuous fiber | |
Fakirov et al. | From bulk polymers to nano-sized materials with controlled nanomorphology |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20100520 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME RS |
|
17Q | First examination report despatched |
Effective date: 20110610 |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20120807 |