Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a sulfur-substituted graphene oxide/epoxy resin composite material, and a preparation method and application thereof. The sulfur-substituted graphene oxide/epoxy resin composite material can be prepared by mixing the sulfur-substituted graphene oxide/epoxy resin through a one-pot method, performing ultrasonic treatment, stirring, heating and the like. The preparation process is simple and feasible, convenient to operate and strong in universality.
The invention provides the following technical scheme:
a sulfur-substituted graphene oxide fluoride/epoxy composite material, the composite material comprising sulfur-substituted graphene oxide fluoride and an epoxy resin.
According to a preferred embodiment of the present invention, the mass percentages of the sulfur-substituted oxyfluoride graphene and the epoxy resin are not particularly limited, and may be any mass percentage known to those skilled in the art to prepare a composite material; preferably, the mass percentage content of the sulfur-substituted graphene oxide fluoride is 0.2-15 wt%; the mass percentage of the epoxy resin is 85-99.5 wt%. Still preferably, the mass percentage content of the sulfur-substituted graphene oxide fluoride is 0.4-10 wt%; the mass percentage of the epoxy resin is 90-99.5 wt%. Preferably, the mass percentage content of the sulfur-substituted graphene oxide fluoride is 0.8-5 wt%; the mass percentage of the epoxy resin is 95-99.2 wt%.
According to a preferred embodiment of the present invention, the epoxy resin is not particularly limited and may be any of epoxy resins of any molecular weight and polymer known to those skilled in the art; preferably, the epoxy resin has a density of 1.0 to 1.5g/cm3。
According to a preferred embodiment of the present invention, the sulfur-substituted graphene oxide fluoride is any one of sulfur-substituted graphene oxide fluoride known to those skilled in the art; preferably, the sulfur content of the sulfur-substituted oxyfluoride graphene is 0.5-5% by mass, for example, 1-2% by mass, such as 1.26% by mass. The mass percentage of oxygen in the sulfur-substituted graphene oxide fluoride is 5-15%, for example, 6-10%, such as 6.7%. The mass percentage of fluorine in the sulfur-substituted graphene oxide fluoride is 1-6%, for example, 2-4%, such as 2.14%.
According to a preferred embodiment of the present invention, the sulfur-substituted fluorinated graphene oxide has at least one of the following structural or performance parameters:
(1) the specific surface area of the sulfur-substituted oxidized fluorinated graphene is 50-100m2G, e.g. 83m2/g;
(2) The thickness of the sulfur-substituted oxidized fluorinated graphene is 10nm-20 mu m;
(3) the number of layers of the sulfur-substituted oxidized fluorinated graphene is 10-60.
According to a preferred embodiment of the present invention, the sulfur-substituted graphene oxide fluoride is prepared by the following method: the method comprises the steps of taking graphite oxide fluoride as a cathode and an anode of an electrolytic cell, preparing electrolyte of the electrolytic cell by using electrolyte containing sulfur elements, and carrying out electrolytic reaction under the action of an external direct current power supply to prepare the sulfur-substituted graphene oxide fluoride.
According to a preferred embodiment of the present invention, the method comprises the steps of:
(1) graphite fluoride oxide is used as a cathode and an anode of an electrolytic cell, and a sulfur element-containing electrolyte, an electrolyte solvent and an optional electrolysis auxiliary agent are added to assemble an electrolytic cell system;
(2) and (2) carrying out an electrolytic stripping reaction on the electrolytic cell system obtained in the step (1) under the action of an external direct current power supply to prepare the sulfur-substituted oxyfluoride graphene dispersed in the electrolyte.
According to a preferred embodiment of the present invention, the method further comprises the steps of:
(3) collecting the sulfur-substituted oxidized fluorinated graphene in the step (2), and ultrasonically dispersing the sulfur-substituted oxidized fluorinated graphene in an organic solvent for stripping; the dispersion was centrifuged, the upper layer was collected and washed with organic solvent, filtered and dried. The sulfur-substituted oxyfluoride graphene generated by electrolysis is light and floats on the surface of the solution after centrifugation, so the upper layer part needs to be collected, filtered, washed and dried.
According to a preferred embodiment of the present invention, in step (1), the electrolyte containing elemental sulfur is selected from any electrolyte containing elemental sulfur known to those skilled in the art to be applicable to the electrolytic cell system of the present invention; preferably, the elemental sulfur-containing electrolyte is selected from thiourea, thiols, and the like.
According to a preferred embodiment of the present invention, in step (1), the electrolyte solvent is any one of electrolyte solvents known to those skilled in the art to be suitable for use in the electrolytic cell system of the present invention; preferably, the electrolyte solvent is selected from propylene carbonate, ethylene carbonate, diethyl carbonate, and the like.
According to a preferred embodiment of the present invention, in step (1), the electrolysis assistant is any electrolysis assistant known to those skilled in the art to be suitable for the electrolytic cell system of the present invention; preferably, the electrolytic auxiliary agent is selected from cetyltrimethylammonium bromide, tetraethylammonium tetrafluoroborate, and the like.
According to a preferable embodiment of the invention, in the step (1), the mass ratio of the graphite fluoride oxide to the electrolyte containing the sulfur element is (1-10) to (2-25), for example, 2 (4-5). The mass ratio of the electrolysis auxiliary agent to the electrolyte containing the sulfur element is (0-10) to (2-25), for example, 2 (4-5). The volume mass ratio of the electrolyte solvent to the electrolyte containing the sulfur element is (20-200mL): (2-25g), for example, 40mL (4-5 g).
According to a preferred embodiment of the present invention, in the step (2), the external dc power source is any external dc power source known to those skilled in the art to be suitable for the electrolytic cell system of the present invention; preferably, the external direct current power supply is selected from a constant voltage external direct current power supply; the voltage of the dc power supply is in the range of 10-30V, for example 15V. The time of the electrolytic reaction is 1 hour or more, for example, 3 hours.
According to a preferable scheme of the invention, in the step (3), the time of ultrasonic dispersion is 0.5-5 h; the ultrasonic dispersion aims to realize stripping of the sulfur-substituted graphite oxide fluoride which is not completely stripped and remains in the sulfur-substituted graphene oxide fluoride, so that the sulfur-substituted graphene oxide fluoride with a thinner layer number is prepared.
According to a preferred embodiment of the present invention, in the step (3), the organic solvent is at least one selected from ethanol, tetrahydrofuran, DMF and acetone.
According to a preferred embodiment of the present invention, the sulfur-substituted fluorinated graphene oxide/epoxy resin composite material has at least one of the following properties:
(1) the bending strength of the sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material is 125-150 MPa;
(2) the interlaminar shear strength of the sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material is 80-110 MPa;
(3) the Young modulus of the sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material is 1.1-1.8 GPa.
The invention provides a preparation method of the sulfur-substituted oxyfluoride graphene/epoxy resin composite material, which comprises the following steps:
i) mixing sulfur-substituted oxidized fluorinated graphene, an organic solvent and epoxy resin to obtain a mixed system;
ii) removing the organic solvent in the mixed system of the step i);
iii) adding a curing agent into the reaction system obtained after the organic solvent is removed in the step ii), and carrying out curing reaction to obtain the sulfur-substituted oxyfluoride graphene/epoxy resin composite material.
According to a preferred embodiment of the present invention, in step i), the mixing manner is any conventional mixing manner known to those skilled in the art, such as stirring and mixing, ultrasonic dispersion and mixing, high-temperature ball milling dispersion and mixing, and the like.
According to a preferred embodiment of the present invention, step i) specifically comprises the following steps:
i') ultrasonically dispersing sulfur-substituted fluorinated graphene oxide in an organic solvent; then adding epoxy resin to continue ultrasonic dispersion to obtain a mixed system.
Preferably, the ultrasonic dispersion is carried out for 1 to 5 hours, and the temperature of the mixed system is controlled below room temperature during the ultrasonic dispersion process, for example, by providing an ice-water bath.
According to a preferred embodiment of the present invention, step i) specifically comprises the following steps:
i') putting the sulfur-substituted oxyfluoride graphene and epoxy resin into a ball-milling tank, adding an organic solvent, and carrying out ball-milling treatment to prepare a mixed system.
Preferably, the rotation speed of the ball milling treatment is 200-.
According to a preferred embodiment of the present invention, in step i), the organic solvent is not particularly limited, and may be any organic solvent capable of dispersing sulfur-substituted graphene oxide and epoxy resin, which is known to those skilled in the art; preferably, the organic solvent is selected from at least one of ethanol, tetrahydrofuran, DMF and acetone.
According to a preferred embodiment of the present invention, in step i), the proportional relationship between the sulfur-substituted oxyfluoride graphene and the epoxy resin in the mixed system is not particularly limited; preferably, the mass ratio of the sulfur-substituted fluorinated oxide graphene to the epoxy resin is 1:6-500, preferably 1: 20-100.
According to a preferred embodiment of the present invention, in step ii), the organic solvent is removed by, for example, a rotary evaporation method; the rotary evaporation is carried out under the condition of negative pressure, and the range of the negative pressure is as follows: -0.1 to 0.08 MPa.
According to a preferred embodiment of the present invention, in step iii), the selection and amount of the curing agent are not particularly limited; preferably, the curing agent is selected from amine curing agents (e.g., alicyclic amines, aromatic amines such as p-phenylenediamine, caprolactam); preferably, the curing agent is added in an amount of 20 to 60 wt% of the amount of the epoxy resin used.
According to a preferred embodiment of the present invention, in step iii), after the curing agent is added, preferably, stirring and mixing are performed first, and then, a curing reaction is performed; the time for stirring and mixing is, for example, 0.5 to 20 hours; before the curing reaction, vacuum drying treatment can be carried out to remove air bubbles in the system.
According to a preferred embodiment of the present invention, in step iii), the curing temperature is, for example, 100 ℃ to 200 ℃ and the curing time is, for example, 4 to 20 hours. Preferably, the curing process is a gradual temperature rise process, such as curing at 120-130 ℃ for 1-3 hours, curing at 135-145 ℃ for 0.5-2 hours, curing at 150-165 ℃ for 1-3 hours, and curing at 170-190 ℃ for 1-3 hours.
The invention provides a preparation method of the sulfur-substituted oxyfluoride graphene/epoxy resin composite material, which comprises the following steps:
a) mixing sulfur-substituted oxidized fluorinated graphene and epoxy resin in a molten state;
b) adding a curing agent into the mixed system obtained in the step a), and carrying out curing reaction to obtain the sulfur-substituted oxyfluoride graphene/epoxy resin composite material.
According to a preferred embodiment of the present invention, in step a), the mass ratio of the sulfur-substituted oxyfluoride graphene to the epoxy resin is 1:6 to 500, preferably 1:20 to 100.
According to a preferred embodiment of the present invention, in step b), the selection and amount of the curing agent are not particularly limited; preferably, the curing agent is selected from amine curing agents (e.g., alicyclic amines, aromatic amines such as p-phenylenediamine, caprolactam); the addition amount of the curing agent is 20-60 wt% of the use amount of the epoxy resin.
According to a preferred embodiment of the present invention, in step b), the curing agent is added after the temperature is reduced to 130-150 ℃.
According to a preferred embodiment of the present invention, in step b), after the curing agent is added, preferably, stirring and mixing are performed first, and then, a curing reaction is performed; the time for stirring and mixing is, for example, 0.5 to 20 hours; before the curing reaction, vacuum drying treatment can be carried out to remove air bubbles in the system.
According to a preferred embodiment of the present invention, in step b), the curing temperature is, for example, 100 ℃ to 200 ℃, and the curing time is, for example, 4 to 20 hours. Preferably, the curing process is a gradual temperature rise process, such as curing at 120-130 ℃ for 1-3 hours, curing at 135-145 ℃ for 0.5-2 hours, curing at 150-165 ℃ for 1-3 hours, and curing at 170-190 ℃ for 1-3 hours.
The invention provides application of the sulfur-substituted oxyfluoride graphene/epoxy resin composite material, which is applied to the fields of coatings, buildings and electrical appliance industry.
The invention has the beneficial effects that:
the invention provides a sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material and a preparation method and application thereof; the sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material has the characteristics of good dispersibility, increased material hardness, enhanced impact resistance and the like. The sulfur-substituted graphene oxide/epoxy resin composite material can be prepared by mixing the sulfur-substituted graphene oxide/epoxy resin through a one-pot method, performing ultrasonic treatment, stirring, heating and the like. The preparation process is simple and feasible, convenient to operate and strong in universality.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that various changes or modifications can be made by those skilled in the art after reading the disclosure of the present invention, and such equivalents also fall within the scope of the invention.
The experimental methods used in the following examples are all conventional methods unless otherwise specified; reagents, materials and the like used in the following examples are commercially available unless otherwise specified.
Example 1
The method comprises the following steps: preparation of sulfur-substituted oxidized fluorinated graphene
2g of graphite fluoride oxide is weighed, placed in a porous plastic tube and adhered to an aluminum or nickel electrode to be used as a cathode and an anode of electrolysis. Adding 4.5g of mercaptan as electrolyte, 40ml of ethanol as electrolyte and 2.0g of tetraethylammonium tetrafluoroborate as electrolytic auxiliary agent, and carrying out electrolytic reaction for 3 hours under the action of a 15V external direct-current power supply to obtain a uniformly dispersed sulfur-substituted oxidized fluorinated graphene solution; the dispersion was subjected to ultrasonic exfoliation, centrifugation, washing with an organic solvent, filtration, and freeze-drying. The sample was collected.
The prepared sulfur-substituted oxidized fluorinated graphene contains 1.26% by mass of sulfur, 6.7% by mass of oxygen and 2.14% by mass of fluorine.
Step two: preparation of sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material
Weighing 10g of the prepared sulfur-substituted oxidized fluorinated graphene, dispersing in tetrahydrofuran, performing ultrasonic treatment for 1 hour, then adding 25g of amine curing agent p-phenylenediamine, and continuing stirring for 10 hours at 80 ℃. Then 50g of a solution having a density of 1.0g/cm was added3The epoxy resin is uniformly stirred. The tetrahydrofuran was removed using a rotary evaporator. The resulting mixed liquid was poured into a prepared mold, placed under vacuum, slowly returned to normal pressure and solidified. The curing process comprises the following steps: the temperature is kept at 120 ℃ for 2 hours, at 140 ℃ for 1 hour, at 160 ℃ for 1 hour and at 180 ℃ for 2 hours. Finally, automatically cooling to room temperature, filtering, washing and drying to obtain sulfurThe composite material is used for replacing an oxidized fluorinated graphene/epoxy resin composite material.
Example 2
The method comprises the following steps: preparation of sulfur-substituted oxidized fluorinated graphene
6g of graphite fluoride oxide is weighed, filled into a porous plastic tube and adhered to an aluminum or nickel electrode to be used as a cathode and an anode of an electrolytic cell. 15g of thiourea was added as an electrolyte, 120ml of acetylacetone was used as an electrolyte, and 5.0g of tetraethylammonium tetrafluoroborate was used as an electrolytic auxiliary. Connecting the anode and the cathode to a direct current constant potential rectifier, quickly stirring, and electrolytically stripping the graphite oxide fluoride for 3 hours at a direct current potential of 15V to obtain a uniformly dispersed sulfur substituted graphene oxide fluoride solution. The dispersion was centrifuged, washed with deionized water, filtered and freeze-dried. The sample was collected.
Step two: preparation of sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material
Weighing 10g of the prepared sulfur-substituted oxidized fluorinated graphene and 50g of the prepared sulfur-substituted oxidized fluorinated graphene, wherein the density of the 50g of the prepared sulfur-substituted oxidized fluorinated graphene is 1.5g/cm3The epoxy resin is placed in a ball milling tank, a small amount of ethanol is added at the same time, the rotating speed is 400 r/min, after ball milling is carried out for 6 hours, the mixture is removed, then the curing agent is added, after mixing and stirring are carried out for 10 hours, the obtained mixture is injected into a prepared mould, and the mould is placed under the vacuum condition, slowly returns to the normal pressure and starts to cure. The curing process comprises the following steps: the temperature is kept at 120 ℃ for 2 hours, at 140 ℃ for 1 hour, at 160 ℃ for 1 hour and at 180 ℃ for 2 hours. And finally, automatically cooling to room temperature, filtering, washing and drying to obtain the sulfur-substituted oxyfluoride graphene/epoxy resin composite material.
Example 3
The method comprises the following steps: preparation of sulfur-substituted fluorinated graphene oxide
Step two: preparation of sulfur-substituted oxidized fluorinated graphene/epoxy resin composite material
Weighing 15g of the prepared sulfur-substituted oxyfluoride graphene and 80g of epoxy resin, mixing the materials in a molten state, stirring for 3h, cooling to 140 ℃, adding 16g of caprolactam serving as a curing agent, stirring for 10 h, injecting the obtained mixture into a prepared mold, placing the mold in a vacuum condition, slowly returning to normal pressure, and starting to solidify. The curing process comprises the following steps: the temperature is kept at 130 ℃ for 2 hours, 145 ℃ for 1 hour, 160 ℃ for 1 hour and 170 ℃ for 2 hours. And finally, automatically cooling to room temperature, filtering, washing and drying to obtain the sulfur-substituted oxyfluoride graphene/epoxy resin composite material.
The bending strength, the interlaminar shear strength and the young's modulus of the sulfur-substituted oxyfluoride graphene/epoxy resin composite material and the epoxy resin of example 1 of the present application were respectively tested, and the specific results are shown in table 1.
TABLE 1 parameters of the composite and epoxy resin of example 1
|
Flexural Strength (MPa)
|
Interlaminar shear strength (MPa)
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Young's modulus (GPa)
|
Example 1
|
138
|
90
|
1.4
|
Epoxy resin
|
117
|
76
|
0.9 |
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.