A kind of method that spitball shape graphene improves 6 impact strength of nylon
Technical field
The invention belongs to the modified fields of macromolecular toughening, and in particular to a kind of spitball shape graphene improves nylon 6 and impacts by force
The method of degree.
Background technique
Nylon yield in five large-engineering plastics is maximum, kind at most, purposes it is most wide, have high mechanical strength, fusing point it is high,
The advantages that wear-resisting, oil resistant, fine heat-resisting performance, is widely used in the fields such as automobile, electronics, machinery, machinery.Due to much answering
There is higher requirement to the toughness of nylon in field, in order to meet these applications, it is necessary to which toughening modifying is carried out to nylon.
Under normal conditions, to the toughening modifying of nylon mainly flexible body toughening, rigid inorganic filler toughening, organic rigid
Three kinds of methods of particle toughening, elastic physical efficiency significantly improves the toughness of nylon material, but will be greatly reduced the rigidity of material simultaneously
And intensity;Inorganic rigid particle and organic rigid-particle can enhance while toughening, but its toughening limited extent.Meanwhile
By the study found that the form of rigid particles will affect the toughening effect of matrix, in sheet, spherical, in acicular texture rigidity
In particle, the rigid particles of chondritic are best to the toughening effect of material.
Graphene is a kind of nano material with two dimensional crystal structure, has many excellent performances.Graphene is both
Most thin material, and most tough material, while it has good elasticity again, stretch range can reach own dimensions
20%, macromolecular toughening mechanism is combined as a result, if Sheet Graphite alkene can be built into chondritic, graphene is bound to become
A kind of ideal toughness-increasing modified material.
Summary of the invention
For existing 6 toughening technology of nylon, the present invention provides a kind of spitball shape graphenes to improve 6 impact strength of nylon
Method.
The purpose of the present invention is achieved through the following technical solutions: a kind of spitball shape graphene improves nylon 6 and impacts by force
The method of degree, the method are using spitball shape graphene toughened Nylon 6, and the spitball shape graphene microballoon is by single-layer graphene
Piece gauffer forms, and microsphere diameter is 500nm~5 μm, and density is 0.2~0.4g/cm3, carbon-to-oxygen ratio is 20~60, and specific surface area is low
In 200m2/g。
Further, the spitball shape graphene microballoon is prepared by the following steps to obtain:
(1) by atomization drying method that single-layer graphene oxide dispersion liquid is dry, obtain graphene oxide microballoon;
(2) the graphene oxide microballoon for obtaining step (1), is placed in reducibility gas atmosphere and is restored, gone back
Former graphene oxide microballoon;
(3) the redox graphene microballoon for obtaining step (2) carries out high-temperature process, and temperature is higher than 1000 DEG C, obtains
Spitball shape graphene microballoon.
Further, in the single-layer graphene oxide dispersion liquid of the step (1), reducing agent can also be contained.It is being atomized
In the process, fold occurs for graphene oxide sheet, meanwhile, reducing agent is attached to sheet surfaces with molecular conformation.The reducing agent is
Hydrogen iodide, hydrogen bromide, hydrazine hydrate, vitamin C, sodium borohydride etc..Reducing agent and single-layer graphene oxide mass ratio be 0.1~
10.Atomization drying temperature in the step (1) is 100~200 DEG C, so that the reducing agent being wrapped in pleated structure is to oxidation
Graphene is tentatively restored.
Further, reducing atmosphere described in step (2) is hydrazine hydrate steam, hydroiodic acid steam, hydrogen, hydrobromic acid
One of steam is a variety of.Reducing condition are as follows: 30min~48h or so is restored at 60~200 DEG C.
Further, high-temperature process temperature described in step (3) be 2500~3000 DEG C, the processing time for 30min~
48h, atmosphere are one of nitrogen, helium, hydrogen argon gas gaseous mixture, argon gas.
Further, the method that the spitball shape graphene improves 6 impact strength of nylon, passes through following steps:
(1) nylon 6 and graphene microspheres weight are matched as 100:0.05~1, is premixed, is mixed in mixing machine
Uniform 6/ graphene premix of nylon is closed, first by nylon 6 and graphene microballoon in vacuum drying oven in 80~105 DEG C before premix
Drying 8~12 hours;
(2) the premix double screw extruder for obtaining step (1) is at 230~250 DEG C of processing temperature, and revolving speed 150~
Melt blending squeezes out under conditions of 250rpm, cooling, is granulated, and 6/ graphene composite material of nylon is made.
The beneficial effects of the present invention are:
1, graphene oxide microballoon is prepared by atomization drying method first in the present invention, by reducing agent before atomization drying
It is added in graphene oxide dispersion, is uniformly mixed, reducing agent is made to be supported on graphene oxide sheet surface with molecular forms.Later
During atomization drying, the oxygen-containing functional group of partial reduction agent and surface of graphene oxide reacts, and product is with solvent
Volatilization and deviate from, remaining reducing agent is then attached to graphene oxide sheet surface with molecular forms, and is wrapped up with its gauffer
Come.Second step uses electronation, under reducing atmosphere, inside graphene oxide microballoon and the oxygen-containing functional group on surface with and also
Former agent is sufficiently reacted, and the generation and release that lower temperature makes gas slowly, avoid group in directly thermal reduction and quickly take off
Except generating gas, the phenomenon that causing volume sharply to expand, thus maintain graphene still combined closely in the form of fold piece and
It does not separate.On the one hand the thermal reduction of third step high temperature makes remaining a small amount of oxygen-containing functional group removing, and repair in graphene oxide sheet
Defect sturcture, on the other hand, make remaining moisture in microballoon, reduzate and unreacted reducing agent removing.In addition, we
It has been surprisingly found that in an experiment, at extreme temperatures under (2500~3000 DEG C), the diameter of graphene microballoon is gradually reduced, and density increases
Greatly, specific surface area reduces.This may be the perfect structure of graphene film, so that graphene fold due under graphitization temperature
Binding force enhances, and active force increases between graphene film, and mutual Distance Shortened gradually makes the compact structure of graphene ball
Change.
2, spitball shape graphene microballoon is used for the plasticized modifier of nylon 6 material, and the graphene particle of chondritic is more held
It is easily dispersed in nylon-6 matrix body, it is better that the micro- fold morphology and structure of graphene microsphere surface impart graphene particle again
Flexibility, relatively common lamella filler can further buffer stress, are similar to elastic particle and act on, improve 6 material of nylon
The impact strength of material.
3, spitball shape graphene toughened Nylon 6 composite material is processed in such a way that melt blending squeezes out, this method operation
Simple process, solvent-free pollution, high production efficiency are suitble to large-scale production.
4, nylon 6 material being modified using graphene, graphene not only increases the impact strength of nylon 6 material,
Also there is facilitation to nylon 6 crystallizations simultaneously, and then further improve the rigidity and heat resistance of material, separately due to graphite
It is comprehensive that the comprehensive performance of alkene can also assign the more excellent antistatic property of material, anti-ultraviolet ageing, anti-flammability and water resistance etc.
Energy.
Detailed description of the invention
Fig. 1 is the microscopic appearance of the spitball shape graphene microballoon through preparation of the embodiment of the present invention.
Fig. 2 is the microscopic appearance of the expanded graphite alkene microballoon through comparative example 2 of the present invention preparation.
Specific embodiment
A kind of method that spitball shape graphene improves 6 impact strength of nylon, steps are as follows:
(1) by atomization drying method that single-layer graphene oxide dispersion liquid is dry, obtain graphene oxide microballoon.The list
Reducing agent can also be contained in layer graphene oxide dispersion, in atomization process, fold occurs for graphene oxide sheet, meanwhile,
Reducing agent is attached to sheet surfaces with molecular conformation.Reducing agent is hydrogen iodide, hydrogen bromide, hydrazine hydrate, vitamin C, sodium borohydride
Deng.Reducing agent and single-layer graphene oxide mass ratio are 0.1~10.Atomization drying temperature is 100~200 DEG C, so that being wrapped in
Reducing agent in pleated structure tentatively restores graphene oxide;
(2) the graphene oxide microballoon for obtaining step (1), is placed in reducibility gas atmosphere, at 60~200 DEG C also
Former 30min~48h obtains redox graphene microballoon;The reducing atmosphere is hydrazine hydrate steam, hydroiodic acid steam, hydrogen
One of bromic acid steam is a variety of;
(3) the redox graphene microballoon for obtaining step (2) carries out high-temperature process, and temperature is higher than 1000 DEG C, obtains
Spitball shape graphene microballoon;Atmosphere is one of nitrogen, helium, hydrogen argon gas gaseous mixture, argon gas, and the processing time is 30min
~48h.Further, the temperature treatment temperature is 2500~3000 DEG C.
It (4) is by weight ratio 100:0.05~1 by nylon 6 and step (3) resulting graphene microballoon, in mixing machine
It is premixed, obtains uniformly mixed 6/ graphene premix of nylon, first dry nylon 6 and graphene microballoon in vacuum before premix
It is dried 8~12 hours in 80~105 DEG C in case;
(5) by the obtained premix double screw extruder of step (4) at 230~250 DEG C of processing temperature, revolving speed 150
Melt blending squeezes out under conditions of~250rpm, cooling, is granulated, and the 6/ graphene composite wood of nylon of impact strength enhancing is made
Material.
The composite material of preparation of the invention is molded using ASTM standard, and injection molding machine is molded under the conditions of 230~260 DEG C
Type, sample molding after temperature be 23 ± 2 DEG C, humidity be 50 ± 5% standard environment in place 88h after test, test environment
It is 23 ± 2 DEG C for temperature, humidity is 50 ± 5%.
The present invention is specifically described below by embodiment, the present embodiment is served only for doing further the present invention
It is bright, it should not be understood as limiting the scope of the invention, those skilled in the art makes one according to the content of foregoing invention
A little nonessential changes and adjustment belong to protection scope of the present invention.
Embodiment 1:
(1) by atomization drying method that single-layer graphene oxide dispersion liquid is dry, obtain graphene oxide microballoon, atomization temperature
Degree is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and 1h is restored at 60 DEG C and is obtained
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 1000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Fold microballoon for diameter at 3~5 μm, as shown in Figure 1, its density is 0.2g/cm3, carbon-to-oxygen ratio 22.8, specific surface area is
190m2/g.Composite material is molded into standard testing batten with injection molding machine and carries out Mechanics Performance Testing, the graphene increases after tested
The room temperature Izod notched impact strength of tough nylon 6 composite material is 25.44KJ/m2。
Embodiment 2:
(1) by atomization drying method that single-layer graphene oxide dispersion liquid is dry, obtain graphene oxide microballoon, atomization temperature
Degree is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and 1h is restored at 90 DEG C and is obtained
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 1000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Fold microballoon for diameter at 3~5 μm, density 0.23g/cm3, carbon-to-oxygen ratio 23.1, specific surface area 181m2/g.It will answer
Condensation material is molded into standard testing batten with injection molding machine and carries out Mechanics Performance Testing, and the nylon 6 of the graphene toughening is multiple after tested
The room temperature Izod notched impact strength of condensation material is 26.56KJ/m2。
Embodiment 3:
(1) by atomization drying method that single-layer graphene oxide dispersion liquid is dry, obtain graphene oxide microballoon, atomization temperature
Degree is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 1000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Fold microballoon for diameter at 3~5 μm, density 0.25g/cm3, carbon-to-oxygen ratio 23.2, specific surface area 166m2/g.It will answer
Condensation material with injection molding machine be molded into standard testing batten carry out the Mechanics Performance Testing graphene toughening after tested nylon 6 it is compound
The room temperature Izod notched impact strength of material is 27.15KJ/m2。
By comparative example 1~3 it is found that final stone can be significantly reduced by improving second step reduction temperature and time
The specific surface area of black alkene microballoon improves density, but influences on carbon-to-oxygen ratio little.This is because second step reduction mainly makes to aoxidize
The group of graphene surface is slowly removed, reduction temperature is low or the time is short will lead to reduction it is insufficient, remaining group exists
It will continue to remove when third portion high-temperature heat treatment, generate gas and graphene film is expanded outward.And spitball shape graphene is micro-
When the large specific surface area of ball, graphene powder less efficient dispersal, toughening effect is impacted.Therefore, taking into account the above, second step is also
Old terms is preferably high reduction temperature and long recovery time.
Embodiment 4:
(1) will be dry containing ascorbic single-layer graphene oxide dispersion liquid by atomization drying method, obtain graphite oxide
The mass ratio of alkene microballoon, vitamin C and graphene oxide is 0.1, and atomization temperature is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 1000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Composite material is molded into standard testing batten with injection molding machine and carries out mechanical property survey by the fold microballoon for diameter at 3~5 μm
Examination, specific nature are as shown in table 1.
Embodiment 5:
(1) will be dry containing ascorbic single-layer graphene oxide dispersion liquid by atomization drying method, obtain graphite oxide
The mass ratio of alkene microballoon, vitamin C and graphene oxide is 1, and atomization temperature is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 1000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Composite material is molded into standard testing batten with injection molding machine and carries out mechanical property survey by the fold microballoon for diameter at 3~5 μm
Examination, specific nature are as shown in table 1.
Embodiment 6:
(1) will be dry containing ascorbic single-layer graphene oxide dispersion liquid by atomization drying method, obtain graphite oxide
The mass ratio of alkene microballoon, vitamin C and graphene oxide is 5, and atomization temperature is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 1000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Composite material is molded into standard testing batten with injection molding machine and carries out mechanical property survey by the fold microballoon for diameter at 3~5 μm
Examination, specific nature are as shown in table 1.
Embodiment 7:
(1) will be dry containing ascorbic single-layer graphene oxide dispersion liquid by atomization drying method, obtain graphite oxide
The mass ratio of alkene microballoon, vitamin C and graphene oxide is 1, and atomization temperature is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 2000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Composite material is molded into standard testing batten with injection molding machine and carries out mechanical property survey by the fold microballoon for diameter at 3~5 μm
Examination, specific nature are as shown in table 1.
Embodiment 8:
(1) will be dry containing ascorbic single-layer graphene oxide dispersion liquid by atomization drying method, obtain graphite oxide
The mass ratio of alkene microballoon, vitamin C and graphene oxide is 1, and atomization temperature is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 3000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Composite material is molded into standard testing batten with injection molding machine and carries out mechanical property survey by the fold microballoon for diameter at 3~5 μm
Examination, specific nature are as shown in table 1.
Embodiment 9:
(1) dry by atomization drying method single-layer graphene oxide dispersion liquid, obtain graphene oxide microballoon, atomization temperature
It is 130 DEG C;
(2) the graphene oxide microballoon for obtaining step (1), is placed in hydrazine hydrate steam, and reductase 12 4h is obtained at 90 DEG C
Redox graphene microballoon;
(3) the redox graphene microballoon that step (2) obtains is put into tube furnace, is continually fed into nitrogen, temperature liter
To 3000 DEG C, 1h is kept the temperature, spitball shape graphene microballoon is obtained;
(4) the spitball shape graphene microballoon for obtaining nylon 6 and step (3) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(5) premix for obtaining step (4) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein spitball shape graphene microballoon is under microcosmic
Composite material is molded into standard testing batten with injection molding machine and carries out mechanical property survey by the fold microballoon for diameter at 3~5 μm
Examination, specific nature are as shown in table 1.
Comparative example 1: the nylon 6 material of graphene is not added.
Comparative example 2: it is directly heat-treated without electronation
(1) single-layer graphene oxide dispersion liquid Hummers method being prepared by atomization drying method is dry, obtains oxygen
Graphite alkene microballoon, atomization temperature are 130 DEG C;
(2) the redox graphene microballoon that step (1) obtains is put into tube furnace, be continually fed into it is hydrogen-argon-mixed,
Temperature rises to 3000 DEG C, and heating rate is 5 DEG C/min, keeps the temperature 1h;
(3) the spitball shape graphene microballoon for obtaining nylon 6 and step (2) mixes in mixing machine by weight 100:0.2
It closes uniformly, obtains 6/ graphene premix of nylon, 90 DEG C of vacuum drying in vacuum drying oven by nylon 6 and graphene microballoon before premix
12 hours
(4) premix for obtaining step (3) melt blending in double screw extruder squeezes out, and melting temperature is 250 DEG C,
Screw speed is 200rpm.
The nylon 6 composite material of graphene toughening is obtained through above step, wherein graphene appearance is black fluffy powder,
As shown in Fig. 2, microcosmic is hollow ball shell of the diameter at 1~10 μm, composite material is molded into standard testing batten with injection molding machine
Mechanics Performance Testing is carried out, specific nature is as shown in table 1.
1 embodiment design parameter of table and property
Comparative example 3~6 by the amount for improving the reducing agent being added before atomization drying it can be found that can be effectively facilitated
Reducing degree of the graphene oxide microballoon before third step processing, this is because reducing agent is dispersed in oxidation with molecular forms
Graphene surface can roll into a ball step-reaction, slow reduced graphene, so that carbon-to-oxygen ratio mentions in the first step and second step with ether ring
It rises, specific surface area reduces.And third step reduction front and back is compared it is found that high-temperature heat treatment causes inside redox graphene microballoon
The group not removed is detached from (carbon-to-oxygen ratio increase), and the swelling graphene interlayer structure of the gas of generation causes specific surface area to rise.But
It is, after reducing agent raising reproducibility is added, graphene microballoon less release gas of energy in third step high-temperature heat treatment,
Volume expansion is reduced, so that structure is more closely knit.Therefore, in order to obtain the graphene microballoon of high density, low specific surface area, add
It is significant for entering reducing agent.
Comparative example 5,7 improves third step reduction it can be found that in the case where guaranteeing first two steps reducing condition unanimous circumstances
Temperature increases specific surface area, and density reduces, this is because the further release of gas causes lamellar structure further to strut.
However, surprisingly, after temperature rises to 3000 DEG C (embodiment 8), specific surface area is greatly lowered, it may be possible to which temperature is high
After graphitization temperature, the big π structure of graphene is repaired, and the binding force between lamella greatly promotes, and interlamellar spacing reduces, because
And make graphene microballoon to center " aggregation ", more densification.
Graphite can be significantly reduced by 3000 DEG C of heat treatments merely it is found that if being added without reducing agent in comparative example 3,9
The specific surface area of alkene microballoon.But comparative example 8 realizes that the preceding most of functional group's removing of heat treatment can it is found that reducing agent is added
To obtain the graphene microballoon of more consolidation.
Comparative example 8 and comparative example 1 it is found that in comparative example directly by graphene oxide microballoon carry out high-temperature heat treatment,
Bulk gas evolution leads to volume rapid expanding when reduction, and specific surface area is high, and density is very low.
When spitball shape graphene microballoon and nylon-6 matrix bluk recombination, big specific surface area can enhance the boundary of graphene and matrix
Effect is glued in face, and more energy are absorbed when so that material is by percussion, play better toughening effect, but work as specific surface area
When excessive, graphene powder is easy to reunite, in the base less efficient dispersal, and stress concentration point is more readily formed instead reduces material
Expect performance.In addition, because the fold-like structures of spitball shape graphene microballoon make its own with extraordinary flexibility, microballoon
Structure is more closely knit, and the toughness of material is destroyed due to being less susceptible to deformation big after microballoon is under pressure.So in practical applications
Effect can be prepared by method disclosed in the patent of invention come balance paper nodular graphite alkene microballoon specific surface area and the degree of packing
Optimal graphene toughener, for the impact strength to raising nylon 6 material, meanwhile, it is higher that graphene also imparts material
Heat resistance, resistance to ag(e)ing and the comprehensive performances such as antistatic, improve water imbibition, extend the application range of nylon 6 material.