CN106566267A - Carbon nanotube modified thermoplastic resin and preparation method thereof - Google Patents

Abstract

The invention discloses a carbon nanotube modified thermoplastic resin and a preparation method thereof. The preparation method may include: mixing and ball-milling carbon nanotubes, functional additives, dispersants, solvents, etc. to obtain pretreated modified carbon nanotubes; using a high-speed dispersion process to combine pretreated modified carbon nanotubes with thermoplastic The resin powder is fully stirred and mixed to obtain a stable and dispersed carbon nanotube/resin mixture; after the carbon nanotube/resin mixture is dried, plastic modification additives are added, melted and extruded by a twin-screw machine, cooled and granulated to obtain the target product . The present invention adopts a one-step process of functionalization and pre-dispersion of carbon nanotubes, which can greatly simplify the process flow; at the same time, using thermoplastic resin powder as a raw material, it can obtain effective mixing and dispersion with pretreated carbon nanotube powders, and then realize carbon nanotubes. Nanotube high volume packing. The invention has obvious advantages such as simple process, environmental protection and low cost, and is a high-efficiency carbon nanotube functional masterbatch preparation technology.

Description

Carbon nanotube modified thermoplastic resin and preparation method thereof

technical field

The invention particularly relates to a carbon nanotube modified thermoplastic resin and a preparation method thereof, belonging to the field of nanocomposite materials.

Background technique

Carbon nanotubes have excellent electrical, mechanical and thermal properties, and are ideal fillers for the preparation of composite materials. However, since carbon nanotube powder is usually composed of severely entangled carbon nanotube "particles", there is a strong van der Waals force between carbon nanotubes, coupled with its huge aspect ratio and specific surface area, it is difficult for carbon nanotubes to Effective dispersion in the polymer matrix limits its performance.

At present, the industrial preparation method of carbon nanotube modified thermoplastic composites is mainly the melt blending method. This method is to melt and blend the carbon nanotubes and matrix resin through the shearing action of the twin-screw machine, and then extrude and cool. Granulate. Due to the chemical inertness of the C-C covalent bond on the surface of carbon nanotubes, the affinity with most resin matrices is not good, coupled with its huge surface area and high aspect ratio, it is easy to form agglomerations, and it is difficult to obtain uniform dispersion through direct melt extrusion process .

Therefore, how to prepare uniformly dispersed carbon nanotube composites is a major obstacle limiting its industrial application. At present, there are mainly two methods to solve the dispersion problem of carbon nanotubes: covalent functionalization and non-covalent functionalization. Covalent functionalization mainly uses strong oxidizing acid to treat carbon nanotubes. Although carbon nanotubes with good dispersion properties can be obtained, strong acid not only destroys the structure of carbon nanotubes and affects their performance, but also causes serious pollution to the environment. . Non-covalent functionalization mainly uses surfactants or hydrophilic polymers to modify carbon nanotubes. Although this method can maintain the integrity of carbon nanotubes to the greatest extent, it will introduce surfactants or Hydrophilic polymers will not only affect the interfacial bonding between carbon nanotubes and matrix materials, but also affect the properties of carbon nanotube thermoplastic composites.

For example, CN103183934A prepares a carbon nanotube composite material by functionalizing carbon nanotubes and melt-blending them with polyethylene terephthalate. For another example, CN103426498A prepares carbon nanotube conductive paste by using N-methylpyrrolidone as a solvent, but uses a large amount of strong oxidizing acid or toxic organic solvent during functionalization of carbon nanotubes, which not only requires high equipment, but also Can't realize industrialized production, and can cause environmental pollution.

Contents of the invention

In view of the deficiencies of the prior art, the main purpose of the present invention is to provide a carbon nanotube modified thermoplastic resin and a preparation method thereof.

For realizing the above-mentioned purpose of the invention, the technical scheme that the present invention adopts comprises:

In some embodiments, a carbon nanotube-modified thermoplastic resin is provided, which is mainly formed by uniformly mixing modified carbon nanotubes, thermoplastic resin, and plastic modification additives that may or may not be added and melt-extruded ; wherein the modified carbon nanotubes are mainly formed by mixing and ball milling carbon nanotubes, functional additives, dispersants and solvents that may be added or not added.

In some embodiments, a method for preparing a carbon nanotube modified thermoplastic resin is provided, comprising:

Perform ball milling on the mixed material mainly composed of carbon nanotubes, functional additives, dispersants, and solvents that can be optionally added or not added to obtain pretreated modified carbon nanotubes;

Fully mix the pretreated modified carbon nanotubes with thermoplastic resin powder to obtain a stable and dispersed carbon nanotube/resin mixture;

The carbon nanotube/resin mixture is dried, mixed with plastic modification additives that may be optionally added or not added, and then melted and extruded to obtain the carbon nanotube modified thermoplastic composite material.

In some preferred embodiments, the preparation method may include the following steps:

(1) Carrying out ball milling treatment to the mixture mainly composed of carbon nanotubes, functional additives, dispersants and solvents to obtain pretreated modified carbon nanotubes;

(2) Using a high-speed dispersion process to fully stir and mix the pretreated modified carbon nanotubes and thermoplastic resin powder to obtain a stable and dispersed carbon nanotube/resin mixture;

(3) After the carbon nanotube/resin mixture is dried, plastic modification additives are added, melted and extruded by a twin-screw machine, cooled and granulated, so as to obtain the carbon nanotube modified thermoplastic composite material.

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) In the preparation process of the carbon nanotube modified thermoplastic resin provided, the functionalization and pre-dispersion treatment are realized in one step, that is, the functionalization is simultaneously realized during the pre-dispersion process, which greatly simplifies the process flow;

(2) In the preparation process of the carbon nanotube modified thermoplastic resin provided, the powder thermoplastic resin is used as the raw material to obtain effective mixing and dispersion with the pretreated modified carbon nanotube powder, and the powder thermoplastic resin and carbon nanotube powder The effective contact area of the body is large, which can realize high-volume filling of carbon nanotubes;

(3) In the preparation process of the carbon nanotube modified thermoplastic resin provided, the functionalization additives and solvents used in the functionalization of carbon nanotubes can be removed, and can be recovered and recycled. It is green and environmentally friendly, and will not introduce Impurities ensure the purity of the carbon nanotubes, thereby ensuring the excellent performance of the thermoplastic composite material modified by the carbon nanotubes.

Description of drawings

Fig. 1 is the preparation process flow chart of a kind of carbon nanotube modified thermoplastic resin in a typical embodiment of the present invention;

Fig. 2 is the scanning electron micrograph of the pre-dispersion modified carbon nanotube in the embodiment 1 of the present invention;

3-5 are scanning electron micrographs of the carbon nanotube thermoplastic composite material obtained in Example 1 of the present invention.

detailed description

In view of the deficiencies in the prior art, the inventor of this case has been able to propose the technical solution of the present invention after long-term research and extensive practice, which mainly realizes carbon nanotubes in one step by adding functionalization aids, dispersants and solvents to ball mill carbon nanotubes. The dispersion and rapid functionalization of tubes, and then the effective mixing and dispersion of pretreated carbon nanotube powder with thermoplastic resin powder as raw material can not only greatly simplify the process, but also effectively overcome the traditional process of directly using strong acid and strong alkali to treat carbon nanotubes. The problems of environmental pollution caused by carbon nanotubes and difficulty in large-scale industrial mass production can also be achieved at the same time as high volume filling of carbon nanotubes.

More specifically, one aspect of the present invention provides a carbon nanotube modified thermoplastic resin, which is mainly composed of modified carbon nanotubes, thermoplastic resin and plastic modification additives that can be optionally added or not added. and formed by melting and extruding; wherein the modified carbon nanotubes are mainly formed by mixing and ball milling carbon nanotubes, functional additives, dispersants and optional solvents that may or may not be added.

One aspect of the present invention provides a method for preparing the carbon nanotube modified thermoplastic resin, comprising:

Perform ball milling on the mixed material mainly composed of carbon nanotubes, functional additives, dispersants, and solvents that can be optionally added or not added to obtain pretreated modified carbon nanotubes;

Fully mix the pretreated modified carbon nanotubes with thermoplastic resin powder to obtain a stable and dispersed carbon nanotube/resin mixture;

The carbon nanotube/resin mixture is dried, mixed with plastic modification additives that may be optionally added or not added, and then melted and extruded to obtain the carbon nanotube modified thermoplastic composite material.

In some preferred embodiments, as shown in Figure 1, the preparation method may include the following steps:

(1) Carrying out ball milling treatment to the mixture mainly composed of carbon nanotubes, functional additives, dispersants and solvents to obtain pretreated modified carbon nanotubes;

(2) Using a high-speed dispersion process to fully stir and mix the pretreated modified carbon nanotubes and thermoplastic resin powder to obtain a stable and dispersed carbon nanotube/resin mixture;

(3) After the carbon nanotube/resin mixture is dried, plastic modification additives are added, melted and extruded by a twin-screw machine, cooled and granulated, so as to obtain the carbon nanotube modified thermoplastic composite material.

More preferably, the mixed material comprises the following components calculated by weight percentage: 1.0% to 20% of carbon nanotubes, 20% to 30% of functional auxiliary agents, 0.01% to 1% of dispersants, and 50% to 60% of solvents %.

Wherein, the carbon nanotubes include single-walled carbon nanotubes or multi-walled carbon nanotubes.

Preferably, the diameter of the carbon nanotubes is 0.4-30nm, the length is 0.1-50um, and the purity is ≥95%.

Wherein, the functional auxiliary agent includes any one or both of hydrogen peroxide, ammonium bicarbonate, sodium bicarbonate, ammonia water, organic amine, formamide, acetamide, diethanolamine, triethanolamine and aniline, organic acid Combinations of the above, and not limited thereto.

Preferably, the organic amine includes any one or a combination of two or more of monoethylamine, diethylamine, triethylamine, ethylenediamine, and oleylamine, but is not limited thereto.

Preferably, the organic acid includes any one or a combination of two or more of formic acid, oxalic acid, acetic acid, succinic acid, maleic anhydride, oxalic acid, malonic acid, and oleic acid, and is not limited thereto.

Wherein, the dispersant includes polyethylene wax, ethylene bisstearamide, barium stearate, zinc stearate, calcium stearate, liquid paraffin, monoglyceride stearate, glyceryl tristearate, Any one of sodium dodecylbenzenesulfonate, sodium dodecylsulfonate, cetyltrimethylammonium bromide, dodecyltrimethylammonium bromide, dipalmitoylphosphatidylcholine A combination of one or two or more in any proportion, and is not limited thereto.

Wherein, the solvent includes ethanol, ethylene glycol, glycerol, isopropanol, butanol, acetone, butanone, cyclohexane, heptane, ethyl acetate, toluene, xylene, N-methylpyrrolidone Any one or a combination of two or more in any proportion, and is not limited thereto.

Wherein, the thermoplastic resin includes polypropylene, polyethylene, polystyrene, polyoxymethylene, polysulfone, polyamide, polybutadiene, polytetrafluoroethylene, polyvinyl chloride, polycarbonate, polyphenylene ether, polyformaldehyde Any one or a combination of two or more of methyl acrylate, rubber, acrylonitrile-butadiene-styrene, polyethylene terephthalate or polybutylene terephthalate, and is not limited to this.

Preferably, the particle size of the thermoplastic resin powder is 20-1000 mesh.

In some preferred embodiments, the ball milling treatment includes a wet ball milling process.

Preferably, the ball milling treatment adopts a rotating speed of 100-1000 rpm and a time of 1.0-24 hours.

Wherein, the plastic modification aid includes any one or a combination of two or more of antioxidants, dispersants, heat stabilizers, plasticizers, coupling agents, and tougheners, but is not limited thereto. These additives can be selected from suitable types known in the industry, and can be obtained from the market, and their dosage can also be adjusted accordingly in accordance with methods known in the industry and combined with the needs of actual applications.

In some embodiments, the equipment used in the high-speed dispersion process is at least selected from a high-speed mixer, a high-shear dispersing emulsifier, and a high-speed mixer, but is not limited thereto.

Preferably, the stirring speed adopted in the high-speed dispersion process is 100-1000 rpm, and the stirring time is 0.5-2 hours.

In some preferred embodiments, the melt extrusion temperature of the twin-screw machine is 140°C-350°C, preferably 200-240°C.

The invention has obvious advantages such as simple process, environmental protection and low cost, is an efficient preparation technology of carbon nanotube functional masterbatch, and has great commercial application value.

The technical solution of the present invention, its implementation process and principle will be further explained in conjunction with several embodiments as follows.

Embodiment 1 The preparation method of the carbon nanotube modified thermoplastic resin specifically comprises the following steps:

1) 400g of hydrogen peroxide solution, 100g of Nanocyl 7000 carbon nanotubes (provided by Belgian Nanocyl company), and 1000g of absolute ethanol are mixed (hydrogen peroxide solution accounts for 20% of the total mass of materials, and carbon nanotubes accounts for 20% of the total mass of materials 5.0%, the hydrogen peroxide solution accounts for 50% of the total mass of the material), adopt star ball mill ball milling, the rotating speed is 300 rpm, and the stirring time is 4 hours to obtain the pretreated modified carbon nanotubes, and its morphology can be referred to Fig. 2 ;

2) Stir the obtained pretreated modified carbon nanotubes and 1880g powder resin polyethylene terephthalate through a high-speed mixer for 2 hours to obtain a carbon nanotube resin mixture, and dry it;

3) the carbon nanotube resin mixture and 10g of plastic modification aids (plastic modification aids account for about 0.5% of the total mass of the mixture, which can include commercially available antioxidants, dispersants, heat stabilizers, plasticizers, One or more of the coupling agent and the toughening agent) are melted and extruded by a twin-screw machine, cooled and pelletized (the extrusion temperature of the twin-screw machine is 220° C.) to obtain a carbon nanotube composite material, and its electrical conductivity is measured as 6.65e ² S/m, its morphology can be seen in Figure 3.

Embodiment 2 The difference between this embodiment and Example 1 is that the carbon nanotube quality is 10.0g (the carbon nanotube accounts for 1.0% of the total mass of the material) in the step (1), and the carbon nanotube polyterephthalic acid The conductivity of the ethylene glycol ester composite material is 1.44eS/m, and its morphology can be seen in Figure 4.

Embodiment 3 The difference between this embodiment and Example 1 is that the quality of step (1) carbon nanotubes is 200.0g (carbon nanotubes account for 10.0% of the total mass of the material), and the carbon nanotube polyethylene terephthalate The electrical conductivity of the glycol ester composite material is 5.66e ² S/m.

Embodiment 4 The difference between this embodiment and Example 1 is that the quality of the carbon nanotubes in step (1) is 400.0g (the carbon nanotubes account for 20.0% of the total mass of the material), and the carbon nanotube polyethylene terephthalate The conductivity of the glycol ester composite material is 1.23e ³ S/m, and its morphology can be seen in Figure 5.

Example 5 The difference between this example and Example 1 is that the ball milling time of step (1) is 2 hours, and the conductivity of the carbon nanotube polyethylene terephthalate composite material is measured to be 3.87e ² S/ m.

Example 6 The difference between this example and Example 1 is that the ball milling time in step (1) is 24 hours, and the conductivity of the carbon nanotube polyethylene terephthalate composite material is measured to be 5.66e ² S/ m.

Embodiment 7 The difference between this embodiment and Example 1 is that the quality of the plastic modification aid in step (3) is 2 g (the plastic modification aid accounts for about 0.01% of the total mass of the mixed material), and the carbon nanotube poly The electrical conductivity of the ethylene terephthalate composite was 6.89e ² S/m.

Embodiment 8 The difference between this embodiment and Example 1 is that the quality of the plastic modification aid in step (3) is 20g (the plastic modification aid accounts for about 1.0% of the total mass of the mixed material), and the carbon nanotube poly The electrical conductivity of the ethylene terephthalate composite is 6.47e ¹ S/m.

Example 9 The difference between this example and Example 1 is that step (3) twin-screw extrusion temperature is 200 ° C, and the measured electrical conductivity of the carbon nanotube polyethylene terephthalate composite material is 5.32 e ² S/m.

Example 10 The difference between this example and Example 1 is that step (3) twin-screw extrusion temperature is 240 ° C, and the measured electrical conductivity of the carbon nanotube polyethylene terephthalate composite material is 5.32 e ² S/m.

It should be noted that the drawings of this embodiment are all in a very simplified form and use imprecise ratios, and are only used for convenience and clarity to assist in describing the embodiment of the present invention. In addition, the various products and related parameters, various reaction participants and process conditions used in the above examples are all typical examples, but after a large number of experiments by the inventor of this case, the other different types listed above Raw materials and other process conditions etc. are also applicable, and also all can reach the claimed technical effect of the present invention.

It should be understood that the above-mentioned embodiments are only to illustrate the technical concept and features of the present invention, the purpose of which is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (10)

1. a kind of carbon nano-tube modification thermoplastic resin, it is characterised in that it is mainly by modified carbon nano-tube, thermoplastic resin and optional Selecting property add or without modifying plastics auxiliary agent uniformly mixing and melting extrusion and formed；Wherein described modified carbon nano-tube mainly by CNT, functionalization auxiliary agent, dispersant and alternative addition or without solvent mixing and ball milling formed.

2. a kind of preparation method of carbon nano-tube modification thermoplastic resin, it is characterised in that include：

To mainly by CNT, functionalization auxiliary agent, dispersant, alternative addition or without the mixed material that constitutes of solvent Ball-milling treatment is carried out, pretreatment modification CNT is obtained；

Pretreatment modification CNT is sufficiently mixed with thermoplastic resin powder, the CNT/mixed with resin of stable dispersion is obtained Thing；

After the CNT/resin compound is dried, with alternative addition or without modifying plastics auxiliary agent mix after, Jing Melting extrusion and obtain the carbon nano-tube modification thermoplastic composite.

3. preparation method according to claim 2, it is characterised in that comprise the steps：

(1) mixed material to being mainly made up of CNT, functionalization auxiliary agent, dispersant, solvent carries out ball-milling treatment, obtains Pretreatment modification CNT；

(2) pretreatment modification CNT is thoroughly mixed with thermoplastic resin powder using high speed dispersing technology, is stablized Scattered CNT/resin compound；

(3) after the CNT/resin compound is dried, modifying plastics auxiliary agent, Jing dual-screw-stem machines melting extrusion cooling are added Granulation, so as to obtain the carbon nano-tube modification thermoplastic composite.

4. the preparation method according to Claims 2 or 3, it is characterised in that the mixed material is comprising in percentage by weight The following component calculated：CNT 1.0%～20%, functionalization auxiliary agent 20%～30%, dispersant 0.01%～1%, solvent 50%～60%.

5. the preparation method according to Claims 2 or 3, it is characterised in that：

The CNT includes SWCN or multi-walled carbon nano-tubes；

Preferably, the caliber of the CNT be 0.4～30nm, length be 0.1～50um, purity >=95%；

And/or, the functionalization auxiliary agent includes hydrogen peroxide, ammonium hydrogen carbonate, sodium acid carbonate, ammoniacal liquor, organic amine, formamide, second Any one in acid amides, diethanol amine, triethanolamine and aniline, organic acid or two or more combinations；

Preferably, the organic amine include any one or two kinds in monoethyl amine, diethylamine, triethylamine, ethylenediamine, oleyl amine with On combination；

Preferably, the organic acid includes formic acid, oxalic acid, acetic acid, butanedioic acid, maleic anhydride, ethanedioic acid, malonic acid, oleic acid In any one or two or more combinations；

And/or, the dispersant includes Tissuemat E, ethylene bis stearamide, barium stearate, zinc stearate, calcium stearate, liquid Body paraffin, glyceryl monostearate, glyceryl tristearate, neopelex, dodecyl sodium sulfate, cetyl In trimethylammonium bromide, DTAB, DPPC any one or it is two or more by any The combination of ratio；

And/or, the solvent includes ethanol, ethylene glycol, glycerine, isopropanol, butanol, acetone, butanone, hexamethylene, heptan Any one in alkane, ethyl acetate, toluene, dimethylbenzene, 1-METHYLPYRROLIDONE or two or more combinations in any proportion；

And/or, the thermoplastic resin includes polypropylene, polyethylene, polystyrene, polyformaldehyde, polysulfones, polyamide, polybutadiene Alkene, polytetrafluoroethylene (PTFE), polyvinyl chloride, Merlon, polyphenylene oxide, polymethyl methacrylate, rubber, acrylonitrile-butadiene- Any one in styrene, polyethylene terephthalate or polybutylene terephthalate or two or more combinations；

Preferably, the particle diameter of the thermoplastic resin powder is 20～1000 mesh.

6. the preparation method according to Claims 2 or 3, it is characterised in that the ball-milling treatment includes wet ball-milling technique；

Preferably, for 100～1000 revs/min, the time is 1.0～24 hours to the rotating speed that the ball-milling treatment is adopted.

7. the preparation method according to Claims 2 or 3, it is characterised in that the modifying plastics auxiliary agent include antioxidant, point Any one in powder, heat stabilizer, plasticizer, coupling agent, toughener or two or more combinations.

8. preparation method according to claim 3, it is characterised in that the equipment that the high speed dispersing technology is adopted is at least selected from height Fast mixer, high-shearing dispersion emulsifying machine and high-speed mixer；

Preferably, for 100～1000 revs/min, the time is 0.5～2 hour to the speed of agitator that the high speed dispersing technology is adopted.

9. preparation method according to claim 3, it is characterised in that described dual-screw-stem machine melting extrusion temperature is 140 DEG C～ 350 DEG C, preferably 200～240 DEG C.

10. the carbon nano-tube modification thermoplastic resin that prepared by the method by any one of claim 2-9.