CN103408895A - Preparation method of graphene/epoxy resin composite material - Google Patents

Abstract

The invention provides a preparation method of a graphene epoxy resin composite material. The graphite oxide is first prepared by the hummer method, and the graphite oxide is treated with an ultrasonic method to obtain graphene. Then ultrasonically disperse in the acetone solution, add epoxy resin matrix, continue ultrasonic stirring, add curing agent after vacuuming, pour and heat after vacuum treatment, and obtain graphene epoxy resin composite material. When the graphene content of the material is 0.5%, the tensile strength of the material is as high as 78.084MPa; when the graphene content gradually increases from 0.1% to 3%, the tensile strength first increases and then decreases, reaching the best at 0.5% , 51.7% higher than pure resin tensile strength. Has good mechanical properties.

Description

A kind of preparation method of graphene epoxy resin composite material

technical field

The invention relates to a method for preparing a graphene epoxy resin composite material. the

Background technique

Graphene has attracted the attention of the scientific community for its excellent mechanical properties, thermal properties, electrochemical properties, etc., especially because graphene has high mechanical properties, if it is added to the polymer matrix as a filler material, it can greatly improve the polymer. The mechanical properties of the material, thus changing the mechanical properties of the polymer itself cannot meet the actual needs. At the same time, epoxy resin has excellent chemical and physical properties, low price, good bonding performance with various materials, and process flexibility are unmatched by other thermosetting materials. It can be used as coatings, adhesives, composite resin matrix, Different fields such as electronic packaging materials have played a huge role. If graphene and resin materials are combined, due to the compatibility of the two, an ideal interface can be formed between the two materials, so that the excellent mechanical properties and thermal properties of graphene can be fully exerted, thereby It can be used as a reinforcing body to enhance the function of resin-based composite materials, and prepare resin-based composite materials with excellent mechanical properties and thermal properties. Therefore, the study of graphene epoxy resin composites has a very broad prospect. the

Many scientists around the world have successfully prepared graphene-reinforced composites and studied the interfacial interaction between matrix and reinforced graphene. Koratkar et al. prepared and studied graphene composites. He also prepared single-walled carbon nanotubes and multi-walled carbon nanotube composites for comparison, and used three composite materials with a content of 0.1±0.002% for performance testing and comparison. The results show that the performance of the graphene composite is significantly higher than that of the carbon nanotube composite. The superiority of graphene in mechanical properties over carbon nanotubes may be related to the high specific surface area of graphene, and the bonding between the filler and the matrix due to the wrinkled surface morphology makes the two interlock, which makes the mechanical properties of graphene materials very good. Graphene can also improve the toughness of composite materials, because when graphene is loaded, it has a high flexural modulus and can absorb energy [Koratkar et al, Enhanced mechanical properties of nanocomposites at Low graphene Content, acsnano, 2009:3:3884] . Yu et al. prepared epoxy-based thermal interface materials with few-layer graphene. They found out. Through thermal conductivity tests, they found that graphene sheets with a thickness of less than 2nm are very suitable as thermal conductivity fillers for epoxy resins. Adding 25% graphene can obtain a composite material with a thermal conductivity of 6.44W/(mk). It is 3000% higher than pure resin [Yu A et al, Graphite nanoplatelet-epoxy composite thermal interface materials, Phys.Chem.C, 2007:111:7565]. However, the dispersion of graphene in the polymer-based composite materials prepared at present is not very ideal. This is because graphene is hydrophilic and cannot be directly exfoliated and dispersed in non-aqueous solutions, and the exfoliation of graphene is not sufficient. Graphene with few sheets or even a single sheet is formed. At the same time, the prepared graphene will undergo irreversible aggregation when it is reduced in aqueous solution, making the dispersion in the matrix poor. the

Contents of the invention

The present invention aims at the above-mentioned problem of prior art, provides a kind of preparation method of composite of graphene and epoxy resin. Prepared according to the following steps:

Step 1: Weigh 2g of artificial graphite, add it to a three-necked flask filled with 250ml of concentrated sulfuric acid, stir mechanically during the addition, then weigh 5g of NaNO ₃ and add it to the three-necked flask already mixed with sulfuric acid and graphite. The reaction was stirred mechanically at room temperature for 1 h. Afterwards, 10 g of KMnO ₄ was added to the system, and the addition was completed within two hours. Stirring was continued for another 72 hours, and then the stirring was stopped. After cooling, an appropriate amount of deionized water, about 200ml, was added into the three-neck flask, and the addition was completed in about 15 minutes. Finally, 30% hydrogen peroxide was added dropwise until the solution turned from brown red to yellow. Then wash with dilute hydrochloric acid and deionized water, until the solution does not contain sulfate ions, and wash to neutrality. Then bake at 70°C for 12 hours to obtain artificial graphite oxide. ;

Step 2: quickly put the graphite oxide obtained in Step 1 into a muffle furnace preheated to 1050°C for heat treatment for 15 seconds, and then disperse it in a solvent to obtain graphene. the

Step 3: first add a certain proportion of acetone solution to the prepared graphene, stir ultrasonically under ice bath conditions, then add a certain proportion of epoxy resin, continue ultrasonic stirring, and then heat and magnetically stir in a water bath to remove the acetone solvent, and then pump After vacuum treatment, a curing agent is added, and after stirring, vacuum treatment is performed, and pouring and heating are carried out to obtain composite material splines. Finally, the composite was reduced with hydrazine. the

A further preferred solution of the present invention is: the graphite is selected from artificial graphite with a large particle size (200 mesh), artificial graphite with a small particle size (200 mesh), and natural graphite. the

A further preferred solution of the present invention is: the method for preparing graphite oxide is selected from one of hummer method and Standenmaier method. the

A further preferred solution of the present invention is: the organic solvent is selected from one of ethanol, acetone and NMP. the

A further preferred solution of the present invention is: the graphite oxide treatment method is selected from one of ultrasonic method and thermal expansion method. the

The present invention utilizes the graphite oxide prepared by the hummer method to process the ultrasonic method to prepare the graphene. The graphite oxide sheet prepared by the Hummer method has a wrinkled structure, and at the same time, the sheet contains a large amount of oxygen, that is, the functional groups on the surface of the sheet are relatively rich, and has a good dispersion in pure water, while avoiding the oxidation of the graphite oxide prepared by the Standenmaier method. The graphite carbon layer is severely damaged. Ultrasonic treatment of prepared graphite oxide has a relatively high degree of exfoliation. At the same time, since there is no chemical change in the process of ultrasonic separation, the prepared graphene sheet still has oxygen-containing functional groups, which avoids deoxidation of graphite oxide after thermal expansion treatment. , the decomposition of a large number of functional groups, so that the linkage with the epoxy resin matrix interface becomes poor when compounding. In addition, by controlling the time of ultrasonic stirring during compounding, the agglomeration of dispersed graphene sheets is controlled. Compared with pure resin, the tensile strength of graphite oxide prepared by Hummer method is 51.7% higher than that of pure resin. The mechanical properties are greatly improved. Moreover, the method has the characteristics of simple synthetic process route, mild reaction conditions, abundant sources of raw materials, wide selection range, etc., and has good commercial application prospects. the

Description of drawings

Accompanying drawing 1 is the scanning electron micrograph (SEM) picture of graphene after ultrasonic treatment of graphene oxide prepared by hummer method. the

Accompanying drawing 2 is the scanning electron microscope picture (SEM) picture of the cross-section of the graphene epoxy resin composite material that content is 0.5%. the

Accompanying drawing 3 is the infrared spectrogram (FT-IR) figure of the graphene epoxy resin composite material that content is respectively 0,0.3%, 0.5%. the

Accompanying drawing 4 is the tensile strength curve graph of the graphene epoxy resin composite material that content is respectively 0,0.1%, 0.2%, 0.5%, 1%, 2%, 3%. the

Detailed ways

The present invention is described in detail below in conjunction with accompanying drawing and embodiment:

Example 1

Weigh 2g of artificial graphite, add it to a three-necked flask filled with 250ml of concentrated sulfuric acid, stir mechanically during the addition, then weigh 5g of _NaNO3 and add it to the three-necked flask already mixed with sulfuric acid and graphite. The reaction was stirred mechanically at room temperature for 1 h. Afterwards, 10 g of KMnO ₄ was added to the system, and the addition was completed within two hours. Stirring was continued for another 72 hours, and then the stirring was stopped. After cooling, an appropriate amount of deionized water, about 200ml, was added into the three-neck flask, and the addition was completed in about 15 minutes. Finally, 30% hydrogen peroxide was added dropwise until the solution turned from brown red to yellow. Then wash with dilute hydrochloric acid and deionized water, until the solution does not contain sulfate ions, and wash to neutrality. Then bake at 70°C for 12 hours to obtain artificial graphite oxide. Quickly put graphite oxide into a preheated temperature of 1050°C for 15 seconds to obtain graphene. Weigh 0.05g graphene and 10g epoxy resin at a weight ratio of 5:1000, dissolve 0.5g graphene in acetone, and use a cell pulverizer to ultrasonically disperse for 6 cycles (ie 2376s) under ice bath conditions, and then add 10g For epoxy resin, continue to use cell crushing and ultrasonic stirring for 20 cycles (7920s), and then magnetically stir in a water bath at 70°C to remove acetone. After vacuuming in a vacuum oven at 70°C for 2 hours, add 0.6g of 2-ethyl 4-methylimidazole to the resin, stir manually for 5 minutes, then vacuumize in a vacuum oven for 20 minutes, and then perform casting molding, and finally in 80 ℃ for 1h and heat treatment at 120℃ for 3h to obtain a composite material.

As shown in Figure 1, the scanning electron microscope (SEM) analysis shows that the obtained graphene has a high degree of exfoliation and the flakes are thin; as shown in Figure 2, the scanning electron microscope (SEM) analysis shows that the graphene in the cross-section of the obtained product is well dispersed At the same time, the wrinkled structure of graphene makes the hinge ability of graphene and resin groups very good; as shown in the attached figure 3, the infrared spectrum (FT-IR) analysis results show that the vibration peak of the ester bond is formed at the wave number of 1108.28 , indicating that a cross-link of a new bond is formed between graphene and epoxy resin, and the interfacial combination will be tighter. As shown in the accompanying drawing 4, the tensile strength curve shows that the tensile strength of the composite material with a content of 0.5% is 78.084MPa. the

Example 2

The method of operation is the same as in Example 1, except that 0.02g of graphene and 10g of epoxy resin are weighed in a weight ratio of 2:1000, and all the other conditions remain unchanged, so as to finally obtain a graphene-epoxy resin composite material with a content of 0.2%. It was confirmed by infrared spectroscopic (FT-IR) analysis results and scanning electron microscope photos that a chemical bond of ester bond was formed between graphene and epoxy resin, and the interface was closely combined. Graphene is well dispersed in the matrix. The tensile strength of the graphene-epoxy composite with a content of 0.2% is 56.345MPa. the

Example 3

The method of operation is the same as in Example 1, except that 0.2g of graphene and 10g of epoxy resin are weighed in a weight ratio of 2:100, and all the other conditions remain unchanged, so as to finally obtain a graphene-epoxy resin composite material with a content of 2%. It was confirmed by infrared spectroscopic (FT-IR) analysis results and scanning electron microscope photos that a chemical bond of ester bond was formed between graphene and epoxy resin, and the interface was closely combined. The dispersion of graphene in the matrix is not ideal, and there are more agglomerations. The tensile strength of the graphene-epoxy composite with 2% content is 54.574 MPa. the

Example 4

Operation method is the same as embodiment 1, and difference is, 10 cycles (being 3960s) are ultrasonically dispersed with cell pulverizer under ice-bath condition, and all the other conditions are constant, finally obtain the graphene epoxy resin composite material that content is 0.5% . It is confirmed by scanning electron microscope (SEM) photos that graphene with 6 cycles of ultrasound is better dispersed than graphene with 10 cycles of ultrasound. The lamellae are approximately 3.96 microns wide. the

The preferred embodiments of the present invention have been specifically described above, but the present invention is not limited to the described embodiments, and those skilled in the art can also make various equivalent modifications or replacements without departing from the spirit of the present invention. Equivalent modifications or replacements are all included within the scope defined by the claims of the present application. the

Claims (6)

1. the preparation method of a conducting polymer-based nanometer carbon fibers is characterized in that making by following method:

Step 1: take the 2g synthetic graphite, add in the there-necked flask that the 250ml vitriol oil is housed, want mechanical stirring in the process added, then claim the NaNO of 5g ₃Be added among the there-necked flask that is mixed with sulfuric acid and graphite.Mechanical stirring reaction 1h in room temperature.Afterwards, in system, add 10gKMnO ₄, added in two hours.Continue to stir 72h again, then stop stirring, after cooling, add appropriate deionized water in there-necked flask, approximately about 200ml, about 15min adds.Finally drip 30% hydrogen peroxide, until solution is by reddish brown flavescence.Use respectively afterwards dilute hydrochloric acid and deionized water wash, until sulphate-containing ion not in solution, and be washed till neutrality.And then baking 12h makes artificial graphite oxide under 70 ℃;

Step 2: get step 1 gained graphite oxide and put into fast the retort furnace thermal treatment 15s that has been preheating to 1050 ℃, and then disperse in solvent, can obtain Graphene;

Step 3: first the Graphene of preparation is added to a certain proportion of acetone soln, ultrasonic agitation under condition of ice bath, then add a certain proportion of epoxy resin, continue ultrasonic agitation, the heating in water bath magnetic agitation is removed acetone solvent wherein again, adds solidifying agent after vacuumizing afterwards processing, after stirring, vacuumizes processing again, pour into a mould heating, obtain the matrix material batten.Finally with hydrazine, matrix material is reduced.

2. the preparation method of conducting polymer-based nanometer carbon fibers as claimed in claim 1, it is characterized in that: described graphite is selected from large particle diameter synthetic graphite (200 order), small particle size synthetic graphite (200 order), a kind of in natural graphite.

3. the preparation method of conducting polymer-based nanometer carbon fibers as claimed in claim 1 is characterized in that: the described method for preparing graphite oxide is selected from a kind of in hummer method, Standenmaier method.

4. the preparation method of conducting polymer-based nanometer carbon fibers as claimed in claim 1 is characterized in that: described organic solvent is selected from a kind of in ethanol, acetone, NMP.

5. the preparation method of conducting polymer-based nanometer carbon fibers as claimed in claim 1 is characterized in that: the treatment process of described graphite oxide is selected from a kind of in ultrasonic method, dilatometry.

6. one kind by the described method gained of claim 1 to 5 Graphene epoxy resin composite material.

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