WO2017219944A1

WO2017219944A1 - Method for preparing graphene-epoxy resin composite material

Info

Publication number: WO2017219944A1
Application number: PCT/CN2017/088991
Authority: WO
Inventors: 刘海波; 张在忠; 赵永彬; 赵新新
Original assignee: 山东欧铂新材料有限公司
Priority date: 2016-06-20
Filing date: 2017-06-19
Publication date: 2017-12-28
Also published as: CN106009514B; CN106009514A

Abstract

A method for manufacturing a graphene-epoxy resin composite material, comprising the following steps: first, mixing a graphene nanoplatelet with organic solvent, to obtain a dispersion liquid; further mixing the dispersion liquid obtained in the foregoing step with epoxy resin, to obtain a mixed liquor; performing vacuum rotary evaporateion on the mixed liquor obtained in the foregoing step, to obtain a mixture; and at last, adding a curing agent to the mixture obtained in the foregoing step for blending and curing, to obtain the graphene-epoxy resin composite material. For the problem of relatively poor mechanical property of a graphene-modified epoxy resin composite material, lots of experiments and creative searches are performed on multiple steps and parameters in the preparation process. In aspects such as the addition ratio and the evaporation manner, the manner of vacuum rotary evaporateion is used, so as to improve the elimination efficiency of the solvent, and maximally reduce the residue. In addition, in combination with the optimization of the whole operation steps, the performance of the graphene-epoxy resin is further improved.

Description

Method for preparing graphene/epoxy composite material

This application claims priority to Chinese Patent Application No. 201610445273.6, entitled "Preparation of a Graphene/Epoxy Resin Composite Material" by the Chinese Patent Office on June 20, 2016, the entire contents of which are hereby incorporated by reference. The citations are incorporated herein by reference.

Technical field

The invention belongs to the technical field of resin materials, and in particular relates to a method for preparing a graphene/epoxy resin composite material.

Background technique

Epoxy resin refers to an organic compound containing two or more epoxy groups in the molecule. The molecular structure of the epoxy resin is characterized by the active epoxy group in the molecular chain. The epoxy group can be Located at the end, in the middle of the molecular chain or in a ring structure. Since the molecular structure contains an active epoxy group which can be crosslinked with various types of curing agents to form an insoluble three-dimensional network structure, the polymer compound containing an epoxy group in the molecular structure is collectively referred to as an epoxy resin. The cured epoxy resin has good physical and chemical properties. It has excellent bonding strength to the surface of metal and non-metal materials, good dielectric properties, small deformation shrinkage, good dimensional stability, high hardness and flexibility. It has good properties and is stable to alkali and most solvents. It is widely used in various departments of national defense and national economy for casting, impregnation, laminates, adhesives and coatings. However, pure epoxy resin has relatively large brittleness, impact resistance and electrical and thermal conductivity are relatively poor, easy to crack, and can not meet the requirements of practical applications, especially under special extreme conditions. Therefore, the modification of epoxy resin is also a subject that is frequently concerned in the field of resin materials.

Graphene is a new material of a single-layer sheet structure composed of carbon atoms. It is a planar film composed of a carbon atom and a sp2 hybrid orbital composed of a hexagonal honeycomb lattice, and has a two-dimensional material with a carbon atom thickness. As a two-dimensional crystal composed of carbon atoms and only one layer of atomic thickness, it is the thinnest material and the toughest material in the field of application. The breaking strength is 200 times higher than that of steel. The elasticity can reach 20% of its own size. At the same time, graphene has a large theoretical specific surface area, stable physicochemical properties, and can maintain good structural stability under high working voltage and high current rapid charge and discharge. Graphene also has excellent electrical conductivity and can reduce internal resistance; in addition, graphene is almost completely transparent and very dense. It is precisely because graphene has many excellent physical and chemical properties as described above, which are used in energy storage materials, environmental engineering, and sensitive sensing. Widely used, it is called "black gold" or "king of new materials."

Also in the field of composite materials, research on graphene composite materials has always been one of the focuses. Graphene is usually added as a nanofiller to epoxy resin matrix. Appropriate addition can effectively improve the thermal and electrical properties of epoxy resin. And mechanical properties. However, there are still many problems in the existing composite process in the actual production process, which leads to the performance of the graphene epoxy resin composite material is not ideal enough, can not meet the application requirements of various fields, and limits the promotion and development of the composite material.

Therefore, how to find a more optimized method for preparing graphene-modified epoxy resin and improve the performance of graphene/epoxy resin composite materials has become an important problem that many resin manufacturers and first-line application developers in the industry need to solve.

Summary of the invention

In view of the above, the technical problem to be solved by the present invention is to provide a method for preparing a graphene/epoxy composite material, and the method for preparing the graphene-modified epoxy resin provided by the invention can effectively improve the mechanical properties of the composite material. Moreover, the preparation method is simple and mild, and is suitable for large-scale industrial production.

The invention provides a preparation method of a graphene/epoxy composite material, comprising the following steps:

A) mixing the graphene microchip with an organic solvent to obtain a dispersion;

B) after the dispersion obtained in the above step and the epoxy resin are mixed again, a mixed liquid is obtained;

C) after the mixture obtained in the above step is subjected to vacuum spinning, a mixture is obtained;

D) adding the curing agent to the mixture obtained in the above step, and then curing to obtain a graphene/epoxy composite material.

Preferably, the ratio of the quality of the graphene microchip to the mass of the epoxy resin is 0.01% to 0.1%.

Preferably, the graphene microchip has a sheet diameter of 1 to 20 μm.

Preferably, the organic solvent is one or more of acetone, dimethanol and n-butanol.

Preferably, the mixing is ultrasonic dispersion; the re-mixing is ultrasonic dispersion;

The ultrasonic dispersion has a power of 0.5 to 1.0 kW, and the ultrasonic dispersion has a time of 0.5 to 1.5 hours.

Preferably, the temperature of the vacuum spinning is 10 to 50 ° C;

The pressure of the vacuum spinning is 0.01 to 0.07 MPa;

The speed of the vacuum spinning is 20 to 80 r/min.

Preferably, the epoxy resin is a bisphenol A type epoxy resin.

Preferably, the blending is agitation mixing;

The stirring time is 15 to 30 minutes, and the stirring speed is 1000 to 2000 r/min.

Preferably, the mass ratio of the curing agent to the epoxy resin is (2 to 3): 5;

The curing agent includes one or more of polyamide 300, polyamide 2004, 4-diaminodiphenylmethane, and T31 curing agent.

Preferably, the curing temperature is 60 to 80 ° C;

The curing time is 3 to 5 hours.

The present invention provides a method for preparing a graphene/epoxy composite material, comprising the steps of: firstly mixing a graphene microchip with an organic solvent to obtain a dispersion; and then dispersing the dispersion obtained by the above step with an epoxy resin After mixing again, a mixed liquid is obtained; the mixture obtained in the above step is vacuum-screwed to obtain a mixture; finally, the mixture obtained in the above step is added to a curing agent to be blended, and then cured to obtain a graphene/epoxy composite. Compared with the prior art, the present invention is directed to the problem that the mechanical properties of the graphene-modified epoxy resin composite material are not ideal, and a large number of experiments and creative explorations between various steps and parameters in the preparation process are found. In the solution blending method, graphene is not only difficult to be uniformly and uniformly dispersed, but also because of the strong adsorption of graphene, the solvent is difficult to remove and is easy to remain, thereby affecting the performance of the composite material. The present invention adopts a vacuum rotary steaming method. Improves solvent removal efficiency, minimizes residue, and optimizes overall process steps, further improving the performance of graphene/epoxy composites, while also increasing the utility ratio of graphene and reducing the addition. Quantity, saving production costs. The experimental results show that the tensile strength of the graphene-modified epoxy resin prepared by the invention is up to 32% higher than that of the epoxy resin.

detailed description

For a better understanding of the invention, the preferred embodiments of the invention are described in the accompanying claims,

All the raw materials of the present invention are not particularly limited in their source, and are commercially available or prepared according to a conventional method well known to those skilled in the art.

The purity of all the raw materials of the present invention is not particularly limited, and the present invention preferably employs a conventional purity used in the field of analytically pure or resin materials.

In the present invention, first, a graphene microchip is mixed with an organic solvent to obtain a dispersion. The graphene microchip of the present invention is not particularly limited, and may be prepared by a conventional method or commercially available as a graphene microchip. It is preferably 1 to 20 μm, more preferably 3 to 17 μm, still more preferably 6 to 14 μm, and most preferably 9 to 11 μm. The organic solvent in the present invention is not particularly limited, and may be an organic solvent for dispersing graphene microchips well known to those skilled in the art. The present invention is to improve the dispersion and the spinning effect, and the organic solvent is preferably acetone or two. One or more of methanol and n-butanol are more preferably acetone, dimethanol or n-butanol, more preferably acetone or dimethanol. The present invention is directed to improving the dispersion and swirling effect, the mixing preferably being ultrasonic dispersion; the ultrasonically dispersed power is preferably from 0.5 to 1.0 kW, more preferably from 0.6 to 0.9 kW, most preferably from 0.7 to 0.8 kW; The time of dispersion is preferably from 0.5 to 1.5 hours, more preferably from 0.7 to 1.3 hours, and most preferably from 0.9 to 1.1 hours.

The present invention then remixes the dispersion obtained in the above step with an epoxy resin to obtain a mixed solution. The epoxy resin of the present invention is not particularly limited, and may be an epoxy resin well known to those skilled in the art, and may be prepared according to a conventional method or commercially available. The epoxy resin of the present invention is preferably a bisphenol A type. The epoxy resin is more preferably an E-51 bisphenol A type epoxy resin. The ratio of the graphene microchip and the epoxy resin is not particularly limited in the present invention. In order to improve the dispersion and the performance of the composite material, the ratio of the graphene microchip mass to the mass of the epoxy resin is preferably 0.01%. 0.1%, more preferably 0.02% to 0.09%, still more preferably 0.03% to 0.08%, and most preferably 0.05% to 0.06%. The present invention is to improve the dispersion and the swirling effect, and the remixing is preferably ultrasonic dispersion; the power of the ultrasonic dispersion is preferably 0.5 to 1.0 kW, more preferably 0.6 to 0.9 kW, and most preferably 0.7 to 0.8 kW; The time for ultrasonic dispersion is preferably from 0.5 to 1.5 hours, more preferably from 0.5 to 1.0 hours, still more preferably from 0.6 to 0.9 hours, and most preferably from 0.7 to 0.8 hours.

In the present invention, the mixture obtained in the above step is subjected to vacuum spinning to obtain a mixture. The vacuum rotary steaming of the present invention can improve the evaporation effect and the performance of the composite under specific conditions, the vacuum The temperature of the rotary steaming is 10 to 50 ° C, more preferably 15 to 45 ° C, still more preferably 20 to 40 ° C, most preferably 25 to 35 ° C; and the pressure of the vacuum spinning is 0.01 to 0.07 MPa, more preferably 0.02 to 0.06 MPa, most preferably 0.03 to 0.05 MPa; and the speed of the vacuum spinning is 20 to 80 r/min, more preferably 30 to 70 r/min, and most preferably 40 to 60 r/min.

The invention explores creatively between various steps and parameters in the preparation process, and adopts vacuum rotary steaming and specific vacuum spinning conditions, and combines specific graph diameter and proportion of graphene microchips to improve solvent removal. Efficiency, minimizing residue and further improving the performance of graphene-modified epoxy resin.

The present invention finally adds the curing agent to the mixture obtained in the above step, and then solidifies to obtain a graphene/epoxy composite material.

The curing agent is not particularly limited, and the curing agent for epoxy resin, which is well known to those skilled in the art, may be prepared according to a conventional method or commercially available. The curing agent of the present invention preferably comprises polyamide 300. One or more of polyamide 2004, 4-diaminodiphenylmethane and T31 curing agent, more preferably polyamide 300, polyamide 2004, 4-diaminodiphenylmethane or T31 curing agent, more specifically preferred It is a polyamide 300. The amount of the curing agent to be added in the present invention is not particularly limited. In order to improve the dispersion and the properties of the composite material, the mass ratio of the curing agent to the epoxy resin is preferably (2 to 3): 5, more preferably (2.1 to 2.9): 5, more preferably (2.2 to 2.8): 5, most preferably (2.4 to 2.6): 5. The blending and mixing of the present invention is preferably agitation and mixing. The conditions for the agitation and mixing in the present invention are not particularly limited, and the conditions of stirring and mixing well known to those skilled in the art may be used, and those skilled in the art may according to actual production conditions, product requirements, and The quality requirement is selected and adjusted. The stirring time of the present invention is preferably 15 to 30 minutes, more preferably 17 to 27 minutes, most preferably 20 to 25 minutes; and the stirring rotation speed is preferably 1000 to 2000 r/min. It is more preferably 1200 to 1800 r/min, and most preferably 1400 to 1600 r/min.

In order to improve the mechanical properties of the final product and enhance the curing effect, the blending step preferably further includes an exhausting step; the exhausting step of the present invention is not particularly limited, and those skilled in the art can according to actual production conditions, product requirements, and The quality requirements are selected and adjusted. The venting step of the present invention is preferably carried out under vacuum conditions, more specifically at 0.01 to 0.07 MPa, with agitation of the bubbles until no bubbles are present.

The conditions of the curing of the present invention are not particularly limited, and are cured by those skilled in the art. The conditions may be selected, and those skilled in the art may select and adjust according to actual production conditions, product requirements, and quality requirements. The curing temperature of the present invention is preferably 60 to 80 ° C, more preferably 62 to 78 ° C, and most preferably 65. ～75 ° C; the curing time is preferably from 3 to 5 hours, more preferably from 3.5 to 4.5 hours.

The invention obtains the graphene/epoxy resin composite material through the above steps, and the invention is directed to the problem of poor mechanical properties of the graphene/modified epoxy resin composite material, and is carried out between multiple steps and parameters in the preparation process. A large number of experiments and creative explorations have found that graphene in the existing solution blending method is not only difficult to disperse sufficiently uniformly, but also because the strong adsorption of graphene, the solvent is difficult to remove and easily residue, thus affecting the performance of the composite. Thus, vacuum rotary steaming and specific vacuum spinning conditions, especially combined with specific chip diameter and proportion of graphene microchips, improve solvent removal efficiency, minimize residue, and optimize the overall operation steps. Further, the performance of the graphene-modified epoxy resin is further improved, and the utility ratio of the graphene is also improved, the addition amount is reduced, and the production cost is saved. The experimental results show that the tensile strength of the graphene/epoxy composite prepared by the present invention is up to 32% higher than that of the epoxy resin.

In order to further illustrate the present invention, the method for preparing the graphene/epoxy composite material provided by the present invention will be described in detail below with reference to the embodiments, but it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention. The detailed description of the present invention and the specific operation of the present invention are not intended to limit the scope of the present invention, and the scope of the present invention is not limited to the embodiments described below.

Example 1

1) 0.01 g of graphene powder was added to 50 ml of acetone at an ultrasonic power of 0.8 kW, and ultrasonically dispersed in an ice water bath for 1 hour to form a black uniform dispersion.

2) Add 100 g of epoxy resin E-51 to the graphene acetone solution obtained in step 1), ultrasonically disperse for 1 hour in an ice water bath, and ultrasonic power of 0.8 kW. After mixing uniformly, under pressure of 0.05 MPa and at 20 ° C, 40 r At a rate of /min, the solvent was removed by vacuum evaporation.

3) 50 g of polyamide 300 was added to the ultrasonically dispersed mixture obtained in the step 2), and stirred at a high speed for 30 minutes at a rotation speed of 1500 r/min. Place in a vacuum oven and remove air bubbles at room temperature and 0.05 MPa until no bubbles are present in the mixture.

4) The mixture obtained in the step 3) was slowly poured into a mold which was previously coated with a release agent and preheated at 70 °C. It was placed in an oven at 60 ° C for 3 hours, then cooled to room temperature, and demolded to obtain a graphene/epoxy composite.

The tensile strength of the graphene/epoxy composite material prepared according to the above steps of the present invention (the sample size is in accordance with the national standard GB/T 1040.2-2006 for the tensile properties of the resin cast body), and the results show that the embodiment of the present invention The tensile strength of the graphene-modified epoxy resin composite prepared by 1 was 46.8 MPa.

Example 2

1) 0.05 g of graphene powder was added to 50 ml of acetone at an ultrasonic power of 0.8 kW, and ultrasonically dispersed in an ice water bath for 1 hour to form a black uniform dispersion.

2) Add 100 g of epoxy resin E-51 to the graphene acetone solution obtained in step 1), ultrasonically disperse for 1 hour in an ice water bath, and ultrasonic power of 0.8 kW. After mixing uniformly, at a pressure of 0.03 MPa and at 30 ° C, 50 r / At a speed of min, the solvent was removed by vacuum evaporation.

The tensile strength of the graphene/epoxy composite material prepared according to the above steps of the present invention (the sample size is in accordance with the national standard GB/T 1040.2-2006 for the tensile properties of the resin cast body), and the results show that the embodiment of the present invention The tensile strength of the prepared graphene-modified epoxy resin composite material was 50.4 MPa.

Example 3

1) 0.1 g of graphene powder was added to 50 ml of acetone at an ultrasonic power of 0.8 kW, and ultrasonically dispersed in an ice water bath for 1 hour to form a black uniform dispersion.

2) Add 100 g of epoxy resin E-51 to the graphene acetone solution obtained in step 1), ultrasonically disperse for 1 hour in an ice water bath, and ultrasonic power of 0.8 kW. After mixing uniformly, at a pressure of 0.01 MPa and 40 ° C, at 60 r / At a speed of min, the solvent was removed by vacuum evaporation.

The tensile strength of the graphene/epoxy composite material prepared according to the above steps of the present invention (the sample size is in accordance with the national standard GB/T 1040.2-2006 for the tensile properties of the resin cast body), and the results show that the embodiment of the present invention The tensile strength of the prepared graphene-modified epoxy resin composite material was 54.4 MPa.

Comparative example 1

1) 0.01 g of graphene powder was added to 50 ml of acetone, ultrasonic bath for 1.5 hours, power ≥ 250 W;

2) adding 100 g of epoxy resin E-51 to the graphene acetone solution obtained in the step 1), continuing to ultrasonically with an electric ice bath of ≥250 W for 1.5 hours, while mechanically stirring while ultrasonicating;

3) The mixture obtained in the step (2) was placed in an oil bath, and the oil bath was heated to 60 ° C while magnetically stirring for 10 hours to evaporate the acetone. Then placed in a vacuum oven, and heated under reduced pressure for 2 hours to remove residual acetone;

4) The mixture obtained in the step 3) was cooled to room temperature, 50 g of polyamide 300 was added, and magnetic stirring was carried out for 0.5 hour.

5) The mixture obtained in the step 4) was placed in a vacuum oven and depressurized at room temperature for 1 hour. After slowly pouring into the mold, the mold was previously coated with a release agent, pre-cured in an oven at 50 ° C for 7 hours, cured at 110 ° C for 5 hours, cooled to room temperature, demolded and tested for tensile strength.

The tensile strength of the graphene/epoxy composite prepared according to the above steps (the sample size is in accordance with the national standard GB/T1040.2-2006 for tensile properties of resin casts), the results show that the graphite prepared in the above steps The tensile strength of the olefin-modified epoxy resin composite was 45.8 MPa.

Comparative example 2

1) 5 g of graphene powder was added to 500 ml of acetone, ultrasonic bath for 1.5 hours, power ≥ 250 W;

The tensile strength of the graphene/epoxy composite prepared according to the above steps (the sample size is in accordance with the national standard GB/T1040.2-2006 for tensile properties of resin casts), the results show that the graphite prepared in the above steps The tensile strength of the olefin-modified epoxy resin composite was 47.2 MPa.

Comparative example 3

2) Add 100g of epoxy resin E-51 to the graphene acetone solution obtained in step 1), continue to ultrasonically pulsate with ≥250W for 1.5 hours, ultrasonically mechanically stir, mix evenly at 0.01MPa pressure and 40°C Next, the solvent was removed by vacuum spinning at a rate of 60 r/min;

3) The mixture obtained in the step (2) was cooled to room temperature, 50 g of polyamide 300 was added, and magnetic stirring was carried out for 0.5 hour;

4) The mixture obtained in the step 3) was placed in a vacuum oven and depressurized at room temperature for 1 hour. After slowly pouring into the mold, the mold was previously coated with a release agent, pre-cured in an oven at 50 ° C for 7 hours, cured at 110 ° C for 5 hours, cooled to room temperature, demolded and tested for tensile strength.

The tensile strength of the graphene/epoxy composite prepared according to the above steps (the sample size is in accordance with the national standard GB/T1040.2-2006 for tensile properties of resin casts), the results show that the graphite prepared in the above steps The tensile strength of the olefin-modified epoxy resin composite was 48.6 MPa.

The method for preparing a graphene/epoxy composite material provided by the present invention is described in detail above. The principles and embodiments of the present invention are described in detail herein. The description of the above embodiments is only used for The method of the present invention, as well as the core concepts thereof, are included in the best mode of the invention, and are intended to enable any person skilled in the art to practice the invention, including making and using any device or system, and performing any combination. It should be noted that common techniques in the art It will be apparent to those skilled in the art that the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the claims, and may include other embodiments that are apparent to those skilled in the art. Such other embodiments are intended to be included within the scope of the appended claims.

Claims

A method for preparing a graphene/epoxy composite material, comprising the steps of:

A) mixing the graphene microchip with an organic solvent to obtain a dispersion;

B) after the dispersion obtained in the above step and the epoxy resin are mixed again, a mixed liquid is obtained;

C) after the mixture obtained in the above step is subjected to vacuum spinning, a mixture is obtained;

D) adding the curing agent to the mixture obtained in the above step, and then curing to obtain a graphene/epoxy composite material.
The preparation method according to claim 1, wherein the ratio of the graphene microplate mass to the mass of the epoxy resin is 0.01% to 0.1%.
The method according to claim 1, wherein the graphene microchip has a sheet diameter of 1 to 20 μm.
The production method according to claim 1, wherein the organic solvent is one or more selected from the group consisting of acetone, dimethanol, and n-butanol.
The preparation method according to claim 1, wherein the mixing is ultrasonic dispersion; the re-mixing is ultrasonic dispersion;

The ultrasonic dispersion has a power of 0.5 to 1.0 kW, and the ultrasonic dispersion has a time of 0.5 to 1.5 hours.
The preparation method according to claim 1, wherein the vacuum steaming temperature is 10 to 50 ° C;

The pressure of the vacuum spinning is 0.01 to 0.07 MPa;

The speed of the vacuum spinning is 20 to 80 r/min.
The method according to claim 1, wherein the epoxy resin is a bisphenol A type epoxy resin.
The preparation method according to claim 1, wherein the blending is stirring and mixing;

The stirring time is 15 to 30 minutes, and the stirring speed is 1000 to 2000 r/min.
The preparation method according to claim 1, wherein the mass ratio of the curing agent to the epoxy resin is (2 ~ 3): 5;

The curing agent includes polyamide 300, polyamide 2004, 4-diaminodiphenylmethane and T31 curing One or more of the agents.
The preparation method according to claim 1, wherein the curing temperature is 60 to 80 ° C;

The curing time is 3 to 5 hours.