CN111117043B - Heat treatment enhanced graphene microchip/high-density polyethylene composite material and preparation method thereof - Google Patents
Heat treatment enhanced graphene microchip/high-density polyethylene composite material and preparation method thereof Download PDFInfo
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- CN111117043B CN111117043B CN202010144823.7A CN202010144823A CN111117043B CN 111117043 B CN111117043 B CN 111117043B CN 202010144823 A CN202010144823 A CN 202010144823A CN 111117043 B CN111117043 B CN 111117043B
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- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K13/00—Use of mixtures of ingredients not covered by one single of the preceding main groups, each of these compounds being essential
- C08K13/04—Ingredients characterised by their shape and organic or inorganic ingredients
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/04—Carbon
- C08K3/042—Graphene or derivatives, e.g. graphene oxides
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/54—Silicon-containing compounds
- C08K5/541—Silicon-containing compounds containing oxygen
- C08K5/5425—Silicon-containing compounds containing oxygen containing at least one C=C bond
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K7/00—Use of ingredients characterised by shape
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2207/00—Properties characterising the ingredient of the composition
- C08L2207/06—Properties of polyethylene
- C08L2207/062—HDPE
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Abstract
The invention discloses a heat treatment enhanced graphene microchip/high-density polyethylene composite material and a preparation method thereof. According to the invention, the performance of the high-density polyethylene is improved by using the graphene nanoplatelets, so that the high-density polyethylene-based composite material is prepared, and the strength and the rigidity of the composite material are improved; meanwhile, the composite material is subjected to heat treatment, and the strength and the rigidity of the composite material after the heat treatment are obviously improved compared with those of the composite material before the heat treatment. The graphene microchip/high-density polyethylene composite material is low in cost, simple to process and high in chemical stability, can realize large-scale production, and has wider application prospects in the fields of agricultural irrigation, fuel gas conveying, water supply, pollution discharge, mine fine particle solid conveying, oil fields, chemical engineering, post and telecommunications and the like.
Description
Technical Field
The invention belongs to the technical field of materials, and particularly relates to a heat treatment enhanced graphene microchip/high density polyethylene composite material and a preparation method thereof.
Background
Graphene Nanoplatelets (abbreviated as "GNPs") refer to an ultrathin Graphene layered stack having more than 10 carbon layers and a thickness in the range of 5-100nm, and have a thickness significantly thicker than Graphene in the nanometer range but a size up to the micrometer level and a very large aspect ratio. The graphene nanoplatelets can be prepared from graphite oxide, a graphite intercalation compound and expanded graphite, and compared with graphene, the graphene nanoplatelets are simpler in preparation method, low in cost and light in weight, well reserve the ordered carbon sp2 planar structure of the long range of graphite, have excellent mechanical strength, electric conduction and thermal conductivity and good corrosion resistance and high temperature resistance, and are ideal polymer matrix composite reinforcement.
In the field of pipes, metal pipes are gradually replaced by various polyolefin plastic pipes such as PPR/PE/PVC pipes due to their disadvantages of susceptibility to corrosion, short service life, difficulty in installation, etc. Compared with other plastic pipes (PVC, PPR and the like), the high-density polyethylene pipe has the advantages of environmental stress resistance, cracking resistance, good creep resistance, corrosion resistance, good insulating property and the like, and is widely applied to the fields of gas delivery, water supply, pollution discharge, agricultural irrigation, mine fine particle solid delivery, oil fields, chemical engineering, post and telecommunications and the like. And the high-density ethylene environment-friendly material can be recycled after being heated to reach the melting point. However, the current PE pipe has short service life due to poor strength and rigidity. Therefore, it is very important and necessary to develop a high density polyethylene pipe with high strength and rigidity.
Disclosure of Invention
The invention aims to provide a heat-treatment enhanced graphene microchip/high-density polyethylene composite material and a preparation method thereof, which are used for improving the strength and rigidity of the composite material.
In order to achieve the purpose, the invention adopts the technical scheme that:
the graphene nanoplatelets/high-density polyethylene composite material is composed of graphene nanoplatelets, high-density polyethylene and vinyltriethoxysilane, wherein the mass of the graphene nanoplatelets is 0.5-2.0% of the total mass of the graphene nanoplatelets and the high-density polyethylene; the mass of the vinyltriethoxysilane is 20% of that of the graphene nanoplatelets.
Further, the graphene nanoplatelets are ultrathin graphene layered stacks with more than 10 carbon layers and a thickness of 5-100 nm; the parameters are as follows: the carbon content is 98 percent, the diameter of a lamella is 7-10 mu m, the thickness is 40-100nm, and the bulk density is 0.08-0.13 g/ml.
The composite material provided by the invention takes high-density polyethylene with high crystallinity and environmental protection as a matrix, the graphene nanoplatelets with excellent mechanical properties are added, and the vinyltriethoxysilane is added to improve the compatibility problem among materials, so that the composite material provided by the invention has good strength and rigidity. And heat-treating the test piece on the basis of the above to obtain more excellent strength and rigidity. The graphene nanoplatelets are narrow in sheet diameter distribution, uniform in thickness, large in stacking density, easy to add, stable in property, and excellent in comprehensive performances such as heat conduction, reinforcement and barrier.
The preparation method of the graphene microchip/high-density polyethylene composite material comprises the following steps:
(1) and (3) carrying out ball milling on the graphene nanoplatelets in a planetary ball mill for 1h at the rotating speed of 250r/min, and then putting the graphene nanoplatelets into a vacuum drying oven for drying.
(2) Preparing the graphene nanoplatelets, the high-density polyethylene and the vinyl triethoxysilane which are dried to constant weight into raw materials of all components according to a ratio, and uniformly mixing;
(3) melt extrusion: adding the uniformly mixed raw materials into a miniature double-screw extruder, carrying out melt blending at 140 ℃, and extruding at 155 ℃;
(4) injection molding: injection molding the extruded material in the step 3), wherein the injection molding process parameters are as follows: the temperature of the mold is 45-55 ℃, the temperature of the injection tube is 175-185 ℃, the injection pressure is 0.2-0.3 MPa, the pressure maintaining pressure is 0.2-0.3 MPa, the injection time is 22s, and the mold closing time is 30s, so that the graphene microchip/high-density polyethylene composite material sample is obtained.
Preferably, the mold temperature is 50 ℃, the syringe temperature is 180 ℃, the injection pressure is 0.25MPa, and the holding pressure is 0.25 MPa.
(5) And (3) heat treatment: and (3) preserving the temperature of the injection molded sample at 95-105 ℃ for 50-70 min, and cooling to obtain the heat treatment enhanced graphene microchip/high density polyethylene composite material.
Preferably, the heat preservation temperature is 100 ℃, and the heat preservation time is 60 min.
Compared with the prior art, the invention has the following beneficial effects:
according to the invention, the graphene nanoplatelets are adopted instead of graphene as the reinforcing filler, so that the cost of the high-density polyethylene composite material is greatly reduced, and meanwhile, the strength and the rigidity of the composite material can be obviously improved by adding the graphene nanoplatelets into the composite material.
According to the invention, vinyltriethoxysilane is used as a coupling agent, so that the graphene nanoplatelets and the high-density polyethylene are well coupled, good interface adhesion is obtained, and the mechanical property of the composite material is improved.
The invention starts from the theory of influencing the material performance, fully utilizes the advantages and disadvantages of the material property, and greatly improves the mechanical property of the composite material by carrying out heat treatment on the composite material.
The invention has lower cost and simple processing, can be produced on the basis of the prior plastic pipe production process, and is convenient for popularization and application.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, specific embodiments accompanied with examples are described in detail below, it being understood that the examples are illustrative only and are not intended to limit the present invention, and any modifications, equivalents and the like based on the present invention are within the scope of the present invention.
The invention discloses a preparation method of a graphene microchip/high-density polyethylene composite material, which is prepared from the following components in parts by mass: 98-100 parts of high-density polyethylene, 0-2 parts of graphene nanoplatelets and 0-0.4 part of vinyl triethoxysilane (20% of the mass of the graphene nanoplatelets).
Wherein the high density polyethylene has a melt mass flow rate of 20g/10min and a density of 956.4kg/m3(ii) a The graphene nanoplatelets have the carbon content of 98%, the diameter of a lamella layer of 7-10 mu m, the thickness of 40-100nm and the stacking density of 0.08-0.13 g/ml; vinyltriethoxysilane having the molecular formula C8H18O3Si, molecular weight of 190.31 g/mol, relative density of 0.9100, boiling point of 160-161 ℃.
Example 1
(1) And (3) ball-milling a certain amount of graphene nanoplatelets in a planetary ball mill for 1h at the rotating speed of 250r/min, and then putting the graphene nanoplatelets into a vacuum drying oven for drying.
(2) Preparing the raw materials of each component by the graphene nanoplatelets, the high-density polyethylene and the vinyl triethoxysilane which are dried to constant weight according to a ratio, wherein 99.5 parts of the high-density polyethylene, 0.5 part of the graphene nanoplatelets and 0.1 part of the vinyl triethoxysilane are mixed by a customized plastic bag for 15-20 min.
(3) Melt extrusion: adding the uniformly mixed raw materials into a miniature double-screw extruder, carrying out melt blending at the temperature of 140 ℃, and extruding at the temperature of 155 ℃, wherein the rotating speed of the double screws is 30 r/min.
(4) Injection molding: injection molding the extruded material in the step 3), wherein the injection molding process comprises the following steps: the temperature of the mold is 50 ℃, the temperature of the injection tube is 180 ℃, the injection pressure is 0.25MPa, the pressure maintaining pressure is 0.25MPa, the injection time is 22s, and the mold closing time is 30s, so that the graphene microchip/high-density polyethylene composite material sample is obtained.
(5) And (3) heat treatment: and (3) preserving the temperature of the injection molded sample at 100 ℃ for 60min, and air cooling to obtain the heat treatment enhanced graphene microchip/high density polyethylene composite material.
(6) And testing the mechanical property of the composite material, testing the tensile strength of the sample before and after heat treatment by adopting a CMT4104 electronic universal testing machine, and analyzing and calculating the elastic modulus of the sample by utilizing the obtained data.
Example 2
99 parts of high-density polyethylene, 1 part of graphene microchip and 0.2 part of vinyl triethoxysilane are weighed, and a sample is prepared and tested for mechanical properties according to the steps and conditions of example 1.
Example 3
98.5 parts of high-density polyethylene, 1.5 parts of graphene microchip and 0.3 part of vinyl triethoxysilane are weighed. Samples were prepared and tested for mechanical properties according to the procedure and conditions of example 1.
Example 4
98 parts of high-density polyethylene, 2 parts of graphene nanoplatelets and 0.4 part of vinyl triethoxysilane are weighed. Samples were prepared and tested for mechanical properties according to the procedure and conditions of example 1.
Comparative example 1
Weighing 100 parts of high-density polyethylene, 0 part of graphene microchip and 0 part of vinyl triethoxysilane as raw materials, preparing a sample according to the steps and conditions of example 1, and testing mechanical properties.
Comparative example 2
98.5 parts of high-density polyethylene, 1.5 parts of graphene microchip and 0 part of vinyl triethoxysilane are weighed, and a sample is prepared and tested for mechanical properties according to the steps and conditions of example 1.
The tensile properties of the composite material were tested according to the GB/T1040.2-2006 standard using a microcomputer controlled electronic universal tester (model CMT 4104) with a dumbbell test specimen and a tensile rate of 50 mm/min. Each group of samples was tested at least 5 times and the arithmetic mean was taken. The elastic modulus E is the maximum slope of the tangent to the initial linear region of the stress-strain curve.
The tensile strength σ is calculated from the force-displacement (1) using the following expression:
in the formula: f is the maximum load in load-displacement in the composite material stretching process, and N; a. the0For composite material tensile sample strip cross-sectional area, mm2。
Examples 1-4 and comparative example 1 above the tensile strength and modulus of elasticity of the test specimens before heat treatment were tested as follows:
examples 1-4 and comparative example 1 above the tensile strength and modulus of elasticity of the test specimens after heat treatment are tested as follows:
from the above table, it can be seen that before and after the heat treatment, the mechanical properties such as tensile strength and elastic modulus of examples 1 to 4 are improved compared with those of comparative example 1, and the addition amount of the graphene nanoplatelets increases and then decreases.
When the addition amount of the graphene nanoplatelets is 1.0wt% (example 2), the tensile strength of the sample after heat treatment is improved by 16.3% compared with that before heat treatment; when the amount of graphene nanoplatelets added was 1.5wt% (example 3), the elastic modulus of the sample after heat treatment was increased by 41.5% compared to that before heat treatment. The heat treatment eliminates the residual stress in the sample, and the graphene microchip can absorb more energy and block the movement of matrix molecular chains to offset the externally applied force, so that the composite material has better bearing capacity, and the tensile strength and the elastic modulus of the composite material can be better improved.
When the addition amount of the graphene nanoplatelets is 1.5wt%, compared with the comparative example 2, the tensile strength and the elastic modulus of the composite material are improved before and after the heat treatment in the example 3, which shows that the vinyltriethoxysilane enables the graphene nanoplatelets and the high-density polyethylene to be well coupled, so that good interface adhesion is obtained, and the mechanical property of the composite material is improved.
When the addition amount of the graphene nanoplatelets is 2.0wt% (example 4), although the tensile strength and elastic modulus are decreased when compared to the addition amount of the graphene nanoplatelets of 1.0wt% (example 2) due to the agglomeration of the graphene nanoplatelets, they are still higher than those of pure high density polyethylene (comparative example 1), indicating that the reinforcing effect of the graphene nanoplatelets on the composite material is significant.
In conclusion, the graphene nanoplatelet/high-density polyethylene composite material prepared by the invention effectively improves the strength and rigidity of the material, and further enhances the strength and rigidity of the composite material by adding a coupling agent and performing heat treatment on the basis, so that the graphene nanoplatelet/high-density polyethylene composite material has wide application prospect.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (2)
1. A preparation method of a heat treatment enhanced graphene microchip/high density polyethylene composite material is characterized by comprising the following steps: the composite material consists of graphene nanoplatelets, high-density polyethylene and vinyl triethoxysilane, wherein the mass of the graphene nanoplatelets is 0.5-2.0% of the total mass of the graphene nanoplatelets and the high-density polyethylene; the mass of the vinyltriethoxysilane is 20% of that of the graphene nanoplatelets; the preparation method comprises the following steps:
(1) ball-milling the graphene nanoplatelets in a planetary ball mill for 1h at the rotating speed of 250r/min, and then putting the graphene nanoplatelets into a vacuum drying oven for drying;
(2) uniformly mixing the graphene nanoplatelets, the high-density polyethylene and the vinyl triethoxysilane which are dried to constant weight according to a ratio;
(3) melt extrusion: adding the uniformly mixed raw materials into a miniature double-screw extruder, carrying out melt blending at 140 ℃, and extruding at 155 ℃;
(4) injection molding: performing injection molding on the extruded material in the step (3) to obtain a graphene microchip/high-density polyethylene composite material sample;
(5) and (3) heat treatment: carrying out heat treatment on the injection-molded sample, and cooling to obtain a heat-treatment enhanced graphene microchip/high-density polyethylene composite material;
the injection molding process parameters in the step (4) are as follows: the temperature of the mold is 45-55 ℃, the temperature of the injection tube is 175-185 ℃, the injection pressure is 0.2-0.3 MPa, the pressure maintaining pressure is 0.2-0.3 MPa, the injection time is 22s, and the mold closing time is 30 s; the heat treatment temperature in the step (5) is 95-105 ℃, and the heat treatment time is 50-70 min.
2. The method for preparing a graphene nanoplatelet/high density polyethylene composite according to claim 1, wherein the graphene nanoplatelets are ultra-thin graphene layered stacks having more than 10 carbon layers and a thickness in the range of 5-100 nm; the parameters are as follows: the carbon content is 98 percent, the diameter of a lamella is 7-10 mu m, the thickness is 40-100nm, and the bulk density is 0.08-0.13 g/ml.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102492280A (en) * | 2011-11-29 | 2012-06-13 | 电子科技大学 | Poly(aryl ether nitrile) composite material and its preparation method |
| CN107418052A (en) * | 2017-08-01 | 2017-12-01 | 广东工业大学 | A kind of graphene microchip/polymer composites and preparation method thereof |
| CN109401012A (en) * | 2018-10-30 | 2019-03-01 | 福州大学 | A kind of graphene microchip/high-density polyethylene composite material and preparation method thereof |
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| WO2019195374A1 (en) * | 2018-04-03 | 2019-10-10 | Nanotek Instruments, Inc. | Metallized graphene foam having high through-plane conductivity |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102492280A (en) * | 2011-11-29 | 2012-06-13 | 电子科技大学 | Poly(aryl ether nitrile) composite material and its preparation method |
| CN107418052A (en) * | 2017-08-01 | 2017-12-01 | 广东工业大学 | A kind of graphene microchip/polymer composites and preparation method thereof |
| CN109401012A (en) * | 2018-10-30 | 2019-03-01 | 福州大学 | A kind of graphene microchip/high-density polyethylene composite material and preparation method thereof |
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