Polymer composites formed from aggregated carbon nanotube bundles

Abstract

Polymer composites containing carbon nanotubes can be prepared prior to blending the carbon nanotubes with the polymer matrix without disaggregating the carbon nanotubes. The polymer composites can include a polymer matrix containing at least one polymer and a plurality of carbon nanotubes dispersed in the polymer matrix, wherein the carbon nanotubes include a plurality of carbon nanotube bundles that have not been disaggregated prior to being dispersed in the polymer matrix. The carbon nanotubes can be produced by a floating catalyst chemical vapor deposition process. The polymer matrix can be a polyolefin matrix including at least one polyolefin.

Description

Technical Field

[0001] The present invention discloses polymer composite materials and, more specifically, polymer composite materials containing carbon nanotubes. Background Technology

[0002] Carbon nanotubes (CNTs), including single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), are allotropes of carbon containing cylindrical nanoscale carbon structures.

[0003] Due to the excellent combination of mechanical, electrical, and thermal properties, carbon nanotubes have been proposed for numerous applications. In recent years, the cost of carbon nanotubes has decreased significantly, making their incorporation into various applications more feasible. Among the many desirable mechanical properties of carbon nanotubes are high values ​​for tensile strength, strain failure, and tensile modulus. Furthermore, carbon nanotubes exhibit high resistance to fatigue, radiation damage, and heat, thus facilitating their use under harsh conditions.

[0004] Numerous proposed applications of polymer composites containing carbon nanotubes have been explored. For example, incorporating carbon nanotubes into polymer composites can increase the tensile strength and stiffness of the composites, as well as provide increased electrical conductivity, while maintaining the desired properties of the polymer itself, such as lightweight and affordability. Despite the potential benefits of incorporating carbon nanotubes into polymer composites, performance gains close to theoretical values ​​have not yet been achieved, primarily due to insufficient dispersion of the carbon nanotubes in the polymer matrix. Poor dispersion can be particularly problematic for carbon nanotubes with high aspect ratios (average length / diameter of individual tubes) (e.g., greater than about 1000). Invention Overview

[0006] In various aspects, the present invention discloses a polymer composite material comprising: a polymer matrix containing at least one polymer; and a plurality of carbon nanotubes dispersed in the polymer matrix, wherein the carbon nanotubes comprise a plurality of carbon nanotube bundles that have not been deaggregated prior to being dispersed in the polymer matrix.

[0007] In other aspects, this invention disclosure provides a method for preparing a polymer composite material. The method includes: providing a plurality of carbon nanotubes, the plurality of carbon nanotubes comprising a plurality of undeaggregated carbon nanotube bundles; and dispersing the plurality of carbon nanotubes in a polymer matrix comprising at least one polymer to form a polymer composite material.

[0008] These and other features and properties of the compositions and methods disclosed in this invention, as well as their advantageous applications and / or uses, will become apparent from the following detailed description. Attached Figure Description

[0009] To assist those skilled in the art in making and using the subject matter of this invention, reference is made to the accompanying drawings. These drawings are included to illustrate certain aspects of the disclosure of this invention and should not be considered as an exclusive configuration. The disclosed subject matter is capable of considerable modifications, alterations, combinations, and equivalents in form and function, as will be apparent to those skilled in the art, and from whom the disclosure of this invention will be beneficial.

[0010] Figure 1 These are representative TEM images of carbon nanotubes produced using the FCCVD process.

[0011] Figure 2 This is a graph showing the volume resistivity as a function of the carbon nanotube content in the polypropylene composite material.

[0012] Figure 3 This is a graph of Young's modulus as a function of the carbon nanotube content in polypropylene composites.

[0013] Figure 4 These are differential scanning calorimetry (DSC) thermal analysis graphs of samples A1 and C1 (polypropylene control).

[0014] Figures 5A and 5B are representative TEM images of carbon nanotubes dispersed in polypropylene composites.

[0015] Figure 6A and 6B This is a graph showing the modulus and impact resistance of polypropylene composites with various additives as a function of load.

[0016] Figure 7A and 7B These are representative TEM images of polypropylene composites containing carbon black and CNTs.

[0017] Figure 8 The graph shows the surface resistivity as a function of the carbon nanotube content in PA66.

[0018] Figure 9 This is a graph showing the tensile modulus as a function of the carbon nanotube content in PA66.

[0019] Figure 10 The graph shows the tensile strength as a function of the carbon nanotube content in PA66.

[0020] Figure 11 This is a graph showing the flexural modulus as a function of the carbon nanotube content in PA66.

[0021] Detailed description

[0022] The present invention discloses polymer composite materials and, more specifically, polymer composite materials containing carbon nanotubes.

[0023] Advantageously, this invention discloses polymer composite materials and methods for preparing the same, which can provide high tensile strength values ​​and adequate dispersion of carbon nanotubes in a polymer matrix, but do not require de-agglomeration of the carbon nanotubes prior to the formation of the polymer composite material. Conventional methods for producing polymer composite materials containing carbon nanotubes may require various steps to deagglomerate the carbon nanotubes, thereby producing individualized carbon nanotubes from carbon nanotube bundles. Sometimes additional purification of the carbon nanotubes may also be required to achieve satisfactory dispersion of the carbon nanotubes during the formation of the polymer composite material and / or to achieve the desired properties within the polymer composite material. Without deagglomeration, entanglement of carbon nanotubes within the polymer matrix can lead to uneven distribution of carbon nanotubes, thereby reducing the mechanical strength and electrical conductivity of the polymer composite material. However, deagglomeration and other purification steps can increase the complexity and cost of methods for producing polymer composite materials containing carbon nanotubes. Furthermore, carbon nanotubes may also undergo damage during deagglomeration. This invention avoids these difficulties to provide polymer composite materials with properties including, for example, increased strength, increased electrical conductivity, and other beneficial properties. Surprisingly, these properties are maintained even when using carbon nanotubes with a high aspect ratio.

[0024] To achieve the above objectives, this invention discloses the use of carbon nanotubes in the form of carbon nanotube powder. Carbon nanotube powder can be produced directly by float catalyst chemical vapor deposition (FCCVD) or by cutting or otherwise mechanically processing carbon nanotubes obtained by FCCVD or alternative carbon nanotube production processes to provide a low-density carbon nanotube structure. The carbon nanotubes within the carbon nanotube powder can comprise bundles of carbon nanotubes entangled with each other, but can be readily dispersed within the polymer matrix once blended with it. The term "bundle" refers to a structure in which carbon nanotubes are tightly assembled wall-to-wall and exhibits bundle diameters up to about 200 nm, depending on the number and diameter of the carbon nanotubes. Advantageously, the FCCVD process can readily produce carbon nanotube bundles with very low impurity content. As further discussed herein, the carbon nanotube bundles within the carbon nanotube powder can still undergo effective dispersion within the polymer matrix.

[0025] The polymer composite material disclosed in this invention may include a polymer matrix and carbon nanotubes, wherein the carbon nanotubes are introduced into the polymer matrix as carbon nanotube bundles. Preferably, since the polyolefin matrix is ​​readily compatible with carbon nanotubes in the form of multiple carbon nanotube bundles, the polymer matrix may contain at least one polyolefin or be substantially composed of it. Therefore, the polymer composite material disclosed in this invention may include a polyolefin matrix containing at least one polyolefin and a plurality of carbon nanotubes dispersed in the polyolefin matrix, wherein the carbon nanotubes include a plurality of carbon nanotube bundles that have not yet deaggregated before being dispersed in the polyolefin matrix. Preferably, the carbon nanotube bundles may also be in the form of carbon nanotube powder, which may represent a particularly low-density carbon nanotube structure. The carbon nanotubes within the carbon nanotube powder may include carbon nanotube bundles and optionally, in varying proportions, individualized carbon nanotubes entangled with each other and / or with the carbon nanotube bundles.

[0026] Examples of polymers suitable for use in polymer composites disclosed herein include, but are not limited to, polyolefin homopolymers and copolymers, or blends thereof. In some examples, the polyolefin may comprise at least one polyolefin, such as polyethylene, polypropylene, copolymers thereof (including impact copolymers), or any combination thereof. Other polymers that may suitably be present in the polymer composite include homopolymers or copolymers of polystyrene, polyester, polyurethane, polysiloxane, polyacrylate, polyamide, etc., or any combination thereof. Any of the foregoing may be blended with polypropylene or polyethylene in the polymer composites disclosed herein. The polymer may be synthesized prior to the formation of the polymer composite and provided in a form suitable for producing the polymer composite by blending with carbon nanotubes. In non-limiting examples, the polymer may be provided in the form of, but is not limited to, granules, particles, etc., or any combination thereof. Alternatively, the polymer may be formed in situ from a polymer precursor in which carbon nanotubes are dispersed.

[0027] Based on the mass of the polymer composite material, the polymer composite material disclosed in this invention may have a carbon nanotube content of about 0.01% by weight or more, for example, in the range of about 0.05%. From about 10% by weight, or about 0.05% by weight to about 7% by weight, or about 0.05% by weight to about 6% by weight, or about 0.05% by weight to about 2.5% by weight, or about 0.05% by weight to about 1.5% by weight, or about 0.05% by weight to about 0.75% by weight, or about 0.05% by weight to about 0.5% by weight, or about 0.05% by weight to about 0.1% by weight, or about 0.1% by weight to about 10% by weight, or about 0.1% by weight to about 7% by weight, or about 0.1% by weight to about 6% by weight, or about 0.1% by weight to about 2.5% by weight, or about 0.1% by weight to about 1.5% by weight, or about 0.1% by weight to about 0.75% by weight, or about 0.1% by weight to about 0.5% by weight, or about 1% by weight to about 5% by weight, or about 1% by weight to about 2.5% by weight, or about 1% by weight to about 1.5% by weight.

[0028] Furthermore, based on the mass of the polymer composite material, the polymer composite material disclosed in this invention may have a polymer content of about 80% by weight or more, or about 85% by weight or more, or about 90% by weight or more, or about 95% by weight or more, or about 97% by weight or more, or about 98% by weight or more, or about 99% by weight or more, for example, ranging from about 95% by weight to about 99.99% by weight, or about 96% by weight to about 99.99% by weight, or about 97% by weight to about 99.99% by weight, or about 98% by weight to about 99.99% by weight, or about 99% by weight to about 99.99% by weight. The polymer may include any suitable polymer, including but not limited to at least one polyolefin.

[0029] Therefore, in a more specific example, the polymer composite material disclosed in this invention may contain about 0.05% by weight to about 10% by weight of carbon nanotubes and 90% by weight or more of polyolefins, each based on the total mass of the polymer composite material.

[0030] Any carbon nanotubes containing carbon nanotube bundles that can be used without deaggregation and preferably with minimal or no further purification are suitable for use in the polymer composites disclosed herein. In more specific examples, carbon nanotubes can be produced using a floating catalyst chemical vapor deposition (FCCVD) process. An illustrative FCCVD process is disclosed in more detail in U.S. Patent 8,999,285 and International Patent Application Publication WO 2005 / 007926, each of which is incorporated herein by reference. The illustrative FCCVD process can synthesize carbon nanotubes from a vaporized carbon source in a heated chamber. Example carbon sources suitable for the present invention disclosure may include hydrocarbons, such as, but not limited to, acetylene, ethylene, methane, etc., or any combination thereof. Alcohols such as methanol or ethanol may also be suitably used, optionally in combination with the aforementioned hydrocarbons. The heated chamber used in FCCVD can have any suitable temperature under which carbon nanotube formation occurs, for example, temperatures from about 500°C to about 1500°C or from about 600°C to about 1300°C. In some examples, the FCCVD process can be carried out at atmospheric pressure or near atmospheric pressure (1 bar at sea level).

[0031] A suitable FCCVD process can be carried out in the presence of a catalyst that effectively converts carbon vapor into carbon nanotubes. The catalyst can be introduced into the carbon source within the heating chamber and / or before the carbon source enters the heating chamber. Exemplary catalysts suitable for the present invention disclosure may include, but are not limited to, iron-based catalysts, cobalt-based catalysts, nickel-based catalysts, molybdenum-based catalysts, etc., or any combination thereof. Those skilled in the art will be able to implement FCCVD systems and suitable catalysts for the production of carbon nanotubes suitable for this purpose.

[0032] Carbon nanotubes as used herein may include single-walled carbon nanotubes, multi-walled carbon nanotubes, or any combination thereof. Any carbon nanotube may contain discontinuous wall structures along its length, which may introduce discontinuities ranging in length from about 1 nm to about 10 μm, about 100 μm, or about 1000 μm. When present, the discontinuous wall structures do not extend continuously around the circumference of the carbon nanotube, as this would result in the carbon nanotube being divided into two parts. Branched / forked carbon nanotubes and bamboo-like carbon nanotubes are also possible and can be suitably used. Carbon nanotubes may be further characterized in terms of suitable size and / or properties, as described below. It should be noted that suitable size and / or properties of carbon nanotubes may depend on factors including, but not limited to, the type of polymer used, the type of carbon nanotubes present, the type of article manufactured, the desired end-use application, etc., or any combination thereof.

[0033] In non-limiting examples, the diameter of carbon nanotubes can be from about 1 nanometer (nm) to about 500 nm, or from about 5 nm to about 500 nm, or from about 5 nm to about 100 nm, or from about 1 nm to about 50 nm. The length of carbon nanotubes can be from about 0.001 millimeters (mm) (i.e., 1 micrometer) to about 20 mm, or from about 0.001 mm to about 10 mm. The packing density of carbon nanotubes can be about 0.5 g / cm³. 3 Approximately 2.5 g / cm³ 3 or approximately 0.5 g / cm³ 3 Approximately 2.0 g / cm³ 3 or approximately 0.7 g / cm³ 3 Approximately 1.9 g / cm³ 3 The aspect ratio of carbon nanotubes can be about 500 or greater, or about 1000 or greater, for example, about 500 to about 2000, or about 500 to about 10,000, or about 1000 to about 10,000, or about 10,000 to about 50,000, or even greater than 50,000. The strain failure ratio of carbon nanotubes can be about 0.5% to about 20.0%, or about 0.5% to about 15.0%, or about 1.0% to about 15.0%, or about 1.0% to about 10.0%, or about 1.0% to about 8.0%. The surface area of ​​carbon nanotubes, as determined by BET, can be about 20 m². 2 / g to approximately 2000m 2 / g, or about 50m 2 / g to approximately 1000m 2 / g, or about 50m 2 / g to approximately 500m 2 / g, or approximately 500m 2 / g to approximately 1000m 2 / g. The tensile strength of carbon nanotubes can be from about 0.1 GPa to about 4.0 GPa, or from about 0.2 GPa to about 3.2 GPa, or from about 0.3 GPa to about 3 GPa, or from about 0.3 GPa to about 2.8 GPa. The specific strength of carbon nanotubes can be about 1800 kN. m / kg to approximately 2900 kN m / kg, or approximately 2000 kN m / kg to approximately 2700 kN m / kg, or approximately 2200 kN m / kg to approximately 2600kN m / kg. The strength modulus of carbon nanotubes can be from about 1 GPa to about 400 GPa, or from about 5 GPa to about 300 GPa, or from about 5 GPa to about 250 GPa, or from about 5 GPa to about 150 GPa. It should be understood that carbon nanotube properties outside the above ranges are otherwise expected, and it should also be understood that a single carbon nanotube selected within a plurality of carbon nanotubes may fall outside the above ranges.

[0034] Furthermore, the polymer composites described herein are characterized by having high Young's modulus (tensile modulus) and volume resistivity values. In non-limiting examples, the Young's modulus of the polymer composites can be about 2000 MPa or higher, or about 2500 MPa or higher, or about 3000 MPa or higher, or about 4000 MPa or higher, or about 5000 MPa or higher, or about 6000 MPa or higher, for example, ranging from about 2000 MPa to about 3500 MPa, or about 2000 MPa to about 3000 MPa, or about 3000 MPa to about 5000 MPa, or about 4000 MPa to about 6000 MPa, or about 5000 MPa to about 7000 MPa. In some or other examples, the volume resistivity of the polymer composites can be about 1 x 10⁻⁶ MPa. 9 Ohm cm to approximately 9x10 12 Ohm cm, and / or surface resistivity can be approximately 1 x 10 cm. 3 Ohm / sq to approximately 5x10 11 Ohm / sq.

[0035] The carbon nanotubes disclosed in this invention can be treated with an organic acid after their synthesis to remove all or at least a portion of any metallic impurities that may be present within multiple carbon nanotubes. Based on the total mass of the carbon nanotubes, the level of metallic impurities can be reduced to about 5% by weight or less, or about 2% by weight or less, or about 1% by weight or less, or about 0.5% by weight or less, or about 0.1% by weight or less. Preferably, after treatment with the organic acid, the content of metallic impurities can be about 200 ppm or less, or about 100 ppm or less, or about 50 ppm or less, or about 5 ppm or less. Any suitable organic acid can be used to facilitate purification, including but not limited to glycolic acid, ascorbic acid, malonic acid, etc., or any combination thereof. Stronger organic acids, such as methanesulfonic acid, chlorosulfonic acid, etc., can also be suitably used. Inorganic acids such as hydrochloric acid can also be suitable. When used, the organic acid can be used in its pure form or dissolved in water, an aqueous fluid, or an inert organic solvent of any suitable strength, for example, from about 0.1 mol / L (M) to about 5 M, or from about 0.1 M to about 1 M. The carbon nanotubes can be treated with acid at room temperature or below, or heated to reflux at any temperature, preferably with mechanical agitation such as stirring or sonication during treatment. The carbon nanotube powder can be formed before or after purification with acid.

[0036] In addition to carbon nanotubes, the polymer composite materials disclosed in this invention may contain other additives. These additional additives may be added to the polymer composite material at concentrations necessary to perform the intended function. The additional additives may be added to the polymer composite material by any suitable manner and at any suitable point during the production of the polymer composite material, including but not limited to adding the additives before blending with carbon nanotubes, during blending with carbon nanotubes, after blending with carbon nanotubes, or any combination thereof. Those skilled in the art will be able to select and appropriately add additional additives to the polymer composite materials disclosed in this invention. Examples of additional additives include, but are not limited to, plasticizers, adhesive additives, anti-blocking additives, antioxidants, pigments, fillers, processing aids, UV stabilizers, neutralizers, lubricants, surfactants, nucleating agents, etc., or any combination thereof.

[0037] Once suitable carbon nanotubes and optional additives are provided according to the foregoing description, the carbon nanotubes and optional additives can be dispersed in a polymer matrix, preferably a polyolefin matrix or a blend of polyolefin and another type of polymer material, to form a polymer composite material. The carbon nanotubes may comprise unaggregated bundles of carbon nanotubes and can be produced using an FCCVD process. To further prepare carbon nanotubes for incorporation into the polymer matrix, the method disclosed in this invention may also include dissociating and / or shredding the carbon nanotubes prior to forming the polymer composite material by forming carbon nanotube powder. Powder formation can be performed by one or any combination of shredding (e.g., in a mixer), grinding, milling, mulling, homogenization in a high-pressure homogenizer or shear mixer, ultrasonic treatment, stretching dissociation, etc.

[0038] Alternatively, carbon nanotubes can be formed as a liquid dispersion and then wet-blended into a polymer matrix to form a polymer composite. The liquid dispersion may include a solvent and a plurality of carbon nanotubes dispersed in the solvent. Anionic, cationic, or polymeric surfactants may also be present to promote the dispersion of the carbon nanotubes. As described above, carbon nanotubes can be produced by FCCVD and can be in the form of easily dispersed bundles. Carbon nanotubes can be dissolved, dispersed, or any combination thereof in a solvent as solids. Preferably, the carbon nanotube bundles may also be in the form of carbon nanotube powder before being dispersed in the solvent.

[0039] The blending of carbon nanotubes with a polymer matrix can be carried out by any method suitable for dispersing carbon nanotubes in the polymer matrix without deaggregating and / or breaking the carbon nanotube bundles prior to incorporation into the polymer matrix. Exemplary techniques for promoting the dispersion of carbon nanotubes in the polymer matrix may include shearing techniques, including but not limited to melt mixing, extrusion, compounding (e.g., wet compounding), or any combination thereof. As a non-limiting example, carbon nanotubes and polymers can be combined using a melt mixing method that occurs at or above the melting point or softening temperature of the polymer matrix. Melt mixing can occur at any suitable temperature at or above the melting point or softening temperature of the polymer matrix, including, for example, temperatures ranging from about 100°C to about 250°C or from about 110°C to about 230°C. During melt mixing, the temperature may remain constant or vary.

[0040] The present invention discloses a masterbatch polymer composite material comprising carbon nanotubes and a polymer, which can be used to form a masterbatch polymer composite material with a high carbon nanotube loading, such that a polymer composite material with a carbon nanotube loading of about 0.05 wt% to about 10 wt% can be produced by blending a portion of the masterbatch with another polymer that does not contain carbon nanotubes. Those skilled in the art will be able to utilize the benefits of the present invention to prepare such a masterbatch and to prepare polymer composite materials therefrom.

[0041] Other implementation plans

[0042] The present invention also relates to the following non-limiting embodiments.

[0043] Implementation Scheme 1. A polymer composite material comprising:

[0044] A polymer matrix containing at least one polymer; and

[0045] Multiple carbon nanotubes dispersed in a polymer matrix, wherein the carbon nanotubes comprise multiple carbon nanotube bundles that have not yet deaggregated before being dispersed in the polymer matrix.

[0046] Implementation Scheme 2. The polymer composite material according to Implementation Scheme 1, wherein the polymer matrix is ​​a polyolefin containing at least one polyolefin.

[0047] Implementation Scheme 3. The polymer composite material according to Implementation Scheme 2, wherein the polymer composite material comprises about 0.05% by weight to about 10% by weight of carbon nanotubes and about 90% by weight or more of polyolefins, each based on the total mass of the polymer composite material.

[0048] Implementation Scheme 4. The polymer composite material according to Implementation Scheme 2 or Implementation Scheme 3, wherein at least one polyolefin includes polypropylene, polyethylene, copolymers thereof, or any combination thereof.

[0049] Implementation Scheme 5. The polymer composite material according to any one of Implementation Schemes 1-4, wherein the diameter of the carbon nanotubes is about 1 nm to about 1000 nm.

[0050] Implementation Scheme 6. The polymer composite material according to any one of Implementation Schemes 1-5, wherein the length of the carbon nanotubes is from about 1 μm to about 2000 μm.

[0051] Implementation Scheme 7. The polymer composite material according to any one of Implementation Schemes 1-6, wherein the aspect ratio of the carbon nanotubes is about 1000 or greater.

[0052] Implementation Scheme 8. The polymer composite material according to any one of Implementation Schemes 1-7, wherein the carbon nanotubes have one or more of the following properties:

[0053] Approximately 0.5g / cm 3 Approximately 2.5 g / cm³ 3 The bulk density, strain failure ratio of approximately 0.5% to approximately 20.0%, and approximately 25 m 2 / g to approximately 1500 m 2 The surface area is approximately 0.1 GPa to approximately 4.0 GPa, and the tensile strength is approximately 1800 kN. m / kg to approximately 2900 kN Specific strength in m / kg, or modulus of strength from about 1 GPa to about 400 GPa.

[0054] Implementation Scheme 9. The polymer composite material according to any one of Implementation Schemes 1-8, wherein a plurality of carbon nanotubes are produced by a floating catalyst chemical vapor deposition (FCCVD) process.

[0055] Implementation Scheme 10. The polymer composite material according to Implementation Scheme 9, wherein the FCCVD process uses an iron-based catalyst.

[0056] Implementation Scheme 11. A method comprising:

[0057] Provides multiple carbon nanotubes, the multiple carbon nanotubes comprising multiple bundles of carbon nanotubes that have not yet disaggregated; and

[0058] Multiple carbon nanotubes are dispersed in a polymer matrix containing at least one polymer to form a polymer composite material.

[0059] Implementation Scheme 12. The method according to Implementation Scheme 11, wherein the polymer matrix is ​​a polyolefin matrix comprising at least one polyolefin.

[0060] Implementation Scheme 13. The method according to Implementation Scheme 12, wherein the polymer composite material comprises about 0.05 wt% to about 10 wt% of carbon nanotubes and about 90 wt% or more of polyolefins, each based on the total mass of the polymer composite material.

[0061] Implementation Scheme 14. The method according to Implementation Scheme 12 or Implementation Scheme 13, wherein the polyolefin matrix comprises polypropylene, polyethylene, copolymers thereof, or any combination thereof.

[0062] Implementation Scheme 15. The method according to any one of Implementation Schemes 11-14 further includes:

[0063] Multiple carbon nanotubes are pulverized before forming a polymer composite material.

[0064] Implementation Scheme 16. The method according to any one of Implementation Schemes 11-15, wherein dispersion comprises melt mixing.

[0065] Implementation Scheme 17. The method according to any one of Implementation Schemes 11-16, wherein the diameter of the carbon nanotubes is about 1 nm to about 1000 nm.

[0066] Implementation Scheme 18. The method according to any one of Implementation Schemes 11-17, wherein the length of the carbon nanotubes is about 1 μm to about 2000 μm.

[0067] Implementation Scheme 19. The method according to any one of Implementation Schemes 11-18, wherein the aspect ratio of the carbon nanotubes is about 1000 or greater.

[0068] Implementation Scheme 20. The method according to any one of Implementation Schemes 11-19, wherein the carbon nanotubes have one or more of the following properties:

[0069] Approximately 0.5g / cm 3 Approximately 2.5 g / cm³ 3 The bulk density, the strain failure ratio of approximately 0.5% to approximately 20.0%, and the density of approximately 25m³ 2 / g to approximately 1500m 2 The surface area is approximately 0.1 GPa to approximately 4.0 GPa, and the tensile strength is approximately 1800 kN. m / kg to approximately 2900 kN Specific strength in m / kg, or modulus of strength from about 1 GPa to about 400 GPa.

[0070] Implementation Scheme 21. The method according to any one of Implementation Schemes 11-20, wherein a plurality of carbon nanotubes are produced using an FCCVD process.

[0071] Implementation Scheme 22. The method according to Implementation Scheme 21. The FCCVD process described therein uses an iron-based catalyst.

[0072] Implementation Scheme 23. A polymer composite material formed by any one of Implementation Schemes 11-22.

[0073] To facilitate a better understanding of the embodiments disclosed in this invention, the following preferred or representative embodiments are provided. These embodiments should not be construed as limiting or restricting the scope of the invention.

[0074] Example

[0075] Polypropylene composite materials

[0076] Carbon nanotubes are produced using FCCVD processes, such as those described in International Patent Application Publication WO 2005 / 007926. Figure 1 These are transmission electron microscopy (TEM) images of exemplary carbon nanotubes produced using the FCCVD process. The carbon nanotubes primarily consist of bundles of carbon nanotubes with 2-8 walls, diameters ranging from 10-50 nm, and lengths greater than 10 μm. The carbon nanotubes are then processed into carbon nanotube powder.

[0077] The resulting carbon nanotubes were used to form a polymer composite masterbatch (sample A0), which contained 5.26% by weight of carbon nanotubes in polypropylene. The polymer composite masterbatch was formed by melt-mixing carbon nanotubes with polypropylene at a feed rate of 50 g / h and heating to 230 °C. Subsequently, the masterbatch polymer composite was combined with various amounts of additional polypropylene (PP3155, ExxonMobil) by melt-mixing to form polymer composites with lower carbon nanotube loadings (samples A1-A4). All samples also included IRGANOX® 1010 (BASF) as a stabilizer. A comparative sample of separate polypropylene was also prepared (sample C1). The compositional data of the polypropylene composites are summarized in Table 1.

[0078] Table 1

[0079]

[0080] The selected physical properties of samples A0-A4 and C1 were determined according to the test procedures provided below, and the results are compiled in Table 2 below. Notched Izod impact was determined using a method based on ASTM D256. Tensile tests were performed using a method based on ASTM D638 to obtain Young's modulus and fracture strain values. Volume resistivity was determined using a method based on ASTM D257.

[0081] Table 2

[0082]

[0083] Plotting volume resistivity and Young's modulus as functions of carbon nanotube loading, as shown below... Figure 2 and 3 As shown in the figure, the volume resistivity decreases rapidly with increasing carbon nanotube loading, while the Young's modulus increases rapidly with increasing carbon nanotube loading. The thermal flux properties of samples A1 and C1 were also analyzed using differential scanning calorimetry (DSC). Figure 4 As shown in the figure, the peak heat flux of sample A1 occurred at a higher temperature (127.82℃) than that of sample C1 (118.98℃), and faster crystallization kinetics were achieved in the presence of carbon nanotubes.

[0084] The samples were also imaged to determine the degree of dispersion of carbon nanotubes in the polypropylene matrix. Figure 5A and 5B These are transmission electron microscopy (TEM) images of representative samples. As shown in the figure, carbon nanotubes are well dispersed in a polypropylene matrix.

[0085] Polypropylene composite material 2

[0086] In separate experiments, FCCVD carbon nanotubes, carbon black 1, carbon black 2, and talc were extruded together with polypropylene at different concentrations. Figure 6A and 6B Modulus and impact resistance at various additive loadings are shown. Trends indicate that polypropylene composites with CNT additives achieve higher modulus and impact resistance compared to polypropylene composites with other additives, especially at lower additive loadings.

[0087] The samples were also imaged to verify the uniform dispersion of different additives within the polypropylene matrix. Figure 7A and 7B These are TEM images of a representative sample. As shown in the figure, both carbon black and carbon nanotubes are well dispersed in the polypropylene matrix.

[0088] Polyamide composite materials

[0089] Using a method similar to that used for polypropylene, carbon nanotubes from two different sources were melt-blended with PA66 (ZYTEL, Celanese). This was achieved using Thermo Scientific. TM Process 11: Blending was performed using a parallel twin-screw extruder at a feed rate of 20 g / min, a rotation speed of 300 rpm, and a temperature rise to 270 °C. The composition data of the polyamide composites are summarized in Table 4.

[0090] Table 3

[0091]

[0092] Samples for mechanical testing were prepared by injection molding on an Xplore MC 15HT micro-mixer equipped with an IM 12 injection molding machine. The extruder used for the injection molding machine was operated at 50 rpm and 290°C. Selected physical properties of the injection-molded samples, based on D1-D6 and controls, were determined according to the test procedures provided below, and the results are compiled in Table 5 below. Notched Izod impact was determined according to the method based on ASTM D256. Tensile tests were performed according to the method based on ASTM D638 to obtain Young's modulus and fracture strain values. Surface resistivity was determined according to the method based on ASTM D257.

[0093] Table 4

[0094]

[0095] Figure 8 , 9Figures 10 and 11 show the surface resistivity, tensile modulus, tensile strength, and flexural modulus as functions of carbon nanotube loading in PA66, respectively. As shown in the figures, the surface resistivity decreases rapidly with increasing carbon nanotube loading, while the tensile modulus and strength increase rapidly with increasing carbon nanotube loading.

[0096] For the purpose of allowing full permission for such practice, all documents described herein are incorporated herein by reference, including any priority documents and / or test procedures, provided they are not inconsistent with this document. Based on the foregoing general description and specific embodiments, it will be apparent that while the form of the disclosure of this invention has been illustrated and described, various modifications may be made without departing from the spirit and scope of the disclosure. Therefore, it is not intended to limit the disclosure of this invention. For example, the compositions described herein may not contain any components or compositions not expressly described or disclosed herein. Any method may lack any steps not described or disclosed herein. Similarly, the term “comprising” is considered synonymous with the term “including.” Whenever a method, composition, element, or group of elements precedes the transitional phrase “comprising,” it should be understood that we also consider the same composition or group of elements preceding the description of the said composition, element, or plurality of elements with the transitional phrase “consistently composed of,” “composed of,” “selected from,” or “is,” and vice versa.

[0097] Unless otherwise stated, all figures used in this specification and related claims to indicate the amount of an ingredient, properties such as molecular weight, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Therefore, unless indicated to the contrary, the numerical parameters listed in the following specification and appended claims are approximate values ​​that may vary depending on the desired properties sought to be obtained through one or more embodiments described herein. At least, and without attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying ordinary rounding techniques.

[0098] Whenever a numerical range with a lower and upper limit is disclosed, any number falling within that range and any included range are specifically disclosed. In particular, the range of each value disclosed herein (in the form of “about a to about b,” or equivalently, “about a to b,” or equivalently, “about ab”) should be understood to describe each number and range covered by a wider range of values. Furthermore, unless otherwise explicitly and clearly defined by the patentee, the terms in the claims have their ordinary, common meaning. Additionally, the indefinite articles “a” or “an” used in the claims are defined herein to indicate one or more elements introduced therein.

[0099] This document provides one or more illustrative embodiments. For clarity, not all features of the physical implementation are described or shown in this application. It should be understood that in the development of the physical embodiments of the present invention, many implementation-specific decisions must be made to achieve the developer's objectives, such as compliance with system-related, business-related, governmental-related, and other constraints that vary with the implementation and from time to time. While the developer's efforts may be time-consuming, these efforts will be routine tasks for those skilled in the art and will benefit from the present invention disclosure.

[0100] Therefore, the present invention disclosure is well adapted to achieve the stated objects and advantages, as well as those inherent therein. The specific embodiments disclosed above are merely illustrative, as the present invention disclosure can be modified and practiced in different but equivalent ways that will be apparent to those skilled in the art and who will benefit from the teachings herein. Furthermore, the details of the constructions or designs shown herein are not intended to limit the scope of the invention, except as described in the following claims. Therefore, it will be apparent that the specific illustrative embodiments disclosed above can be changed, combined, or modified, and all such changes are considered to be within the scope and spirit of the present invention disclosure. The embodiments illustratively disclosed herein can be suitably practiced in the absence of any elements not specifically disclosed herein and / or any optional elements disclosed herein.

Claims

1. A polymer composite material comprising: A polymer matrix containing at least one polymer; and Multiple carbon nanotubes dispersed in a polymer matrix, wherein the carbon nanotubes comprise multiple carbon nanotube bundles that have not yet deaggregated before being dispersed in the polymer matrix.

2. The polymer composite material according to claim 1, wherein the polymer matrix is ​​a polyolefin matrix containing at least one polyolefin.

3. The polymer composite material according to claim 2, wherein the polymer composite material comprises about 0.05% by weight to about 10% by weight of carbon nanotubes and about 90% by weight or more of polyolefins, each based on the total mass of the polymer composite material.

4. The polymer composite material according to claim 2, wherein at least one polyolefin comprises polypropylene, polyethylene, copolymers thereof, or any combination thereof.

5. The polymer composite material according to claim 1, wherein the diameter of the carbon nanotubes is from about 1 nm to about 1000 nm.

6. The polymer composite material according to claim 1, wherein the length of the carbon nanotubes is from about 1 μm to about 2000 μm.

7. The polymer composite material according to claim 1, wherein the aspect ratio of the carbon nanotubes is about 1000 or greater.

8. The polymer composite material according to claim 1, wherein the carbon nanotubes have one or more of the following properties: Approximately 0.5g / cm 3 Approximately 2.5 g / cm³ 3 The packing density, The strain failure ratio is approximately 0.5% to approximately 20.0%. Approximately 25m 2 / g to approximately 1500m 2 / g of surface area Tensile strength from approximately 0.1 GPa to approximately 4.0 GPa, Approximately 1800kN m / kg to approximately 2900 kN Specific strength per m / kg, or The strength modulus is approximately 1 GPa to approximately 400 GPa.

9. The polymer composite material according to claim 1, wherein a plurality of carbon nanotubes are produced by a floating catalyst chemical vapor deposition (FCCVD) process.

10. The polymer composite material according to claim 9, wherein the FCCVD process uses an iron-based catalyst.

11. A method comprising: Multiple carbon nanotubes are provided, including multiple carbon nanotube bundles that have not yet disaggregated; and Multiple carbon nanotubes are dispersed in a polymer matrix containing at least one polymer to form a polymer composite material.

12. The method of claim 11, wherein the polymer matrix is ​​a polyolefin matrix comprising at least one polyolefin.

13. The method of claim 12, wherein the polymer composite material comprises about 0.05% by weight to about 10% by weight of carbon nanotubes and about 90% by weight or more of polyolefins, each based on the total mass of the polymer composite material.

14. The method of claim 12, wherein the polyolefin matrix comprises polypropylene, polyethylene, copolymers thereof, or any combination thereof.

15. The method of claim 11, further comprising: Multiple carbon nanotubes are pulverized before forming a polymer composite material.

16. The method of claim 11, wherein dispersion comprises melt mixing.

17. The method of claim 11, wherein the diameter of the carbon nanotubes is from about 1 nm to about 1000 nm.

18. The method of claim 11, wherein the length of the carbon nanotubes is from about 1 μm to about 2000 μm.

19. The method of claim 11, wherein the aspect ratio of the carbon nanotubes is about 1000 or greater.

20. The method of claim 11, wherein the carbon nanotubes have one or more of the following properties: Approximately 0.5g / cm 3 Approximately 2.5 g / cm³ 3 The packing density, The strain failure ratio is approximately 0.5% to approximately 20.0%. Approximately 25m 2 / g to approximately 1500m 2 / g of surface area Tensile strength from approximately 0.1 GPa to approximately 4.0 GPa, Approximately 1800kN m / kg to approximately 2900 kN Specific strength per m / kg, or The strength modulus is approximately 1 GPa to approximately 400 GPa.

21. The method of claim 11, wherein a plurality of carbon nanotubes are produced using an FCCVD process.

22. The method of claim 21, wherein the FCCVD process uses an iron-based catalyst.

23. A polymer composite material formed by the method according to claim 11.

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