Graphene epoxy resin composite material and its preparation method

Abstract

The present invention belongs to the technical field of epoxy resin composites, and relates to a graphene epoxy resin composite and a preparation method thereof, which include the following raw materials in parts by mass: 35-50 parts of bisphenol A solid epoxy; 20-30 parts of bisphenol A liquid epoxy; 5-10 parts of toughening agent; 10-20 parts of phenol-type phenolic epoxy; 1-5 parts of graphene; 1-10 parts of curing agent; and 1-5 parts of accelerator. The present invention provides a graphene epoxy resin composite and a preparation method thereof, with good graphene dispersion, and the composite has the characteristics of high conductivity, high strength and light weight.

Description

Technical Field

[0001] The present invention belongs to the technical field of epoxy resin composites, and relates to a graphene epoxy resin composite material and a preparation method thereof. Background Art

[0002] Compared with traditional aircraft materials, carbon fiber reinforced composites are lighter in weight, higher in strength and stiffness values, and also have good corrosion resistance. They are ideal materials for reducing the weight of aircraft structures. However, the composite materials have poor electrical conductivity and anti-damage ability, so there are great potential safety hazards when encountering lightning strikes.

[0003] Graphene is one of the materials with the best known electrical conductivity at present. Graphene lightning protection materials have the ability to replace traditional metal conductive materials in aerospace. At present, the main method of modifying the electrical properties of materials with graphene is to mix graphene as a filler with resin. However, as a nanomaterial, graphene is difficult to be uniformly dispersed in the resin, which limits its application. Summary of the Invention

[0004] In order to solve the problem of graphene dispersion, the present invention provides a graphene epoxy resin composite material and a preparation method thereof. The graphene has good dispersion, and the composite material has the characteristics of high electrical conductivity, high strength and light weight.

[0005] In order to achieve the above object, the nano-graphene conductive filler adopted by the present invention is in the form of a masterbatch. The nano-particles are functionalized by a plasma process and included in the masterbatch, and then mixed into the epoxy resin. A new modified carbon fiber epoxy resin composite material is formed by mixing, and the composite material has a higher electrical conductivity to withstand the high current generated by lightning strikes. The specific technical solution is as follows:

[0006] A graphene epoxy resin composite material, comprising the following raw materials in parts by mass:

[0007]

[0008] Further, the viscosity of the bisphenol A liquid epoxy resin is 10000 - 20000 cp.

[0009] Further, the toughening agent is a nano-particle toughening agent or a rubber toughening agent.

[0010] Further, the viscosity of the phenol novolac epoxy resin is 15000 - 20000 cp.

[0011] Further, the curing agent is micro-powder dicyandiamide, and the particle size is 5 - 10 μm.

[0012] Further, the accelerator is a modified imidazole, a modified amine or a modified urea.

[0013] A preparation method of the described graphene epoxy resin composite material comprises the following steps:

[0014] 1) Prepare each raw material according to the described parts by mass;

[0015] 2) Mix bisphenol A solid epoxy resin with a toughening agent, and under vacuum conditions, heat up to 100°C - 150°C, and stir for 30 min - 40 min to obtain Component One;

[0016] 3) Mix bisphenol A liquid epoxy resin, phenol-type phenolic epoxy, a curing agent, an accelerator, and graphene, heat up to 70°C - 80°C, stir for 60 min - 90 min, and then grind the mixture to obtain Component Two;

[0017] 4) Mix Component One and Component Two at a temperature of 70°C - 80°C, and stir for 30 min - 40 min to obtain a graphene epoxy resin composition;

[0018] 5) Prepare an impregnated resin film from the obtained graphene epoxy resin composition on a film coater;

[0019] 6) Lay the obtained impregnated resin film on fibers on a prepreg machine for impregnation to obtain a prepreg;

[0020] 7) Cut the obtained prepreg, lay it on a mold, and cure it using an autoclave process to obtain a composite material.

[0021] Further, in the step 6), the fiber is carbon fiber or glass fiber.

[0022] Further, in the step 7), the curing temperature is 140°C, the time is 30 min, and the curing pressure is 6 bar.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. The nano-graphene conductive filler adopted in the present invention is in the form of a masterbatch. The nano-particles are functionalized by a plasma process, included in the masterbatch, and then mixed into the epoxy resin. A new modified carbon fiber epoxy resin composite material is formed by mixing. This composite material has a higher electrical conductivity to withstand the high current generated by lightning strikes.

[0025] 2. In the present invention, a high-conductivity nano-graphene masterbatch is used to reinforce the epoxy prepreg. While improving the electrical conductivity of the material, it also takes into account the high strength and low weight of the composite material, and can be used in the fields of aerospace and unmanned aerial vehicles. Specific Embodiments

[0026] The composite material provided by the present invention will be described in detail in combination with specific embodiments.

[0027] The graphene epoxy resin composite provided by the present invention comprises the following raw materials in parts by mass:

[0028]

[0029]

[0030] The viscosity of the bisphenol A liquid epoxy resin of the present invention is 10,000 - 20,000 cp.

[0031] The toughening agent of the present invention is a nano-particle toughening agent or a rubber toughening agent.

[0032] The viscosity of the phenol novolac epoxy resin of the present invention is 15,000 - 20,000 cp.

[0033] The curing agent of the present invention is micronized dicyandiamide with a particle size of 5 - 10 μm.

[0034] The accelerator of the present invention is a modified imidazole, a modified amine or a modified urea.

[0035] The preparation method of the graphene epoxy resin composite provided by the present invention comprises the following steps:

[0036] 1) Prepare each raw material according to the parts by mass;

[0037] 2) Mix the bisphenol A solid epoxy resin with the toughening agent, heat it to 100°C - 150°C under vacuum conditions, and stir for 30 min - 40 min to obtain Component One;

[0038] 3) Mix the bisphenol A liquid epoxy resin, phenol novolac epoxy, curing agent, accelerator, and graphene, heat it to 70°C - 80°C, stir for 60 min - 90 min, and then grind the mixture to obtain Component Two;

[0039] 4) Mix Component One and Component Two at a temperature of 70°C - 80°C, and stir for 30 min - 40 min to obtain a graphene epoxy resin composition;

[0040] 5) Prepare an impregnated resin film from the obtained graphene epoxy resin composition on a film coater;

[0041] 6) Lay the prepared impregnated resin film on the fiber on a prepreg machine for impregnation to obtain a prepreg;

[0042] 7) Cut the obtained prepreg, lay it on a mold, and cure it using a autoclave process to obtain a composite material.

[0043] In step 6), the fiber is carbon fiber or glass fiber.

[0044] In step 7), the curing temperature is 140 °C, the time is 30 min, and the curing pressure is 6 bar.

[0045] In the present invention, a graphene epoxy resin composition will be obtained first, and then the composition will be pre-impregnated with fibers to obtain a composite material. Finally, the strength of the composite material is related to the pre-impregnated fibers, but the strength meets the requirements of the composite material strength. However, the surface resistance of the final composite material is small, but the conductivity is large.

[0046] The following describes several preferred embodiments to illustrate the composite material and its properties provided by the present invention.

[0047] Example 1

[0048] The graphene epoxy resin composite material comprises the following raw materials in mass fractions:

[0049] 45 parts of bisphenol A solid epoxy resin;

[0050] 20 parts of bisphenol A liquid epoxy resin;

[0051] 8 parts of toughening resin;

[0052] 13 parts of phenol-type phenolic epoxy resin;

[0053] 3 parts of graphene;

[0054] 8 parts of micronized dicyandiamide;

[0055] 3 parts of accelerator (modified imidazole).

[0056] The viscosity of the bisphenol A liquid epoxy resin in this example is 20000 cp.

[0057] The viscosity of the phenol-type phenolic epoxy resin in this example is 15000 cp.

[0058] The particle size of the curing agent micronized dicyandiamide is 5 μm.

[0059] In this example, the preparation method of the graphene epoxy resin composite material comprises the following steps.

[0060] First, prepare a resin composition.

[0061] (1) Add bisphenol A solid epoxy resin and rubber toughening agent to a reaction kettle, under vacuum conditions, heat up to 130 °C, and stir for 40 min to obtain Component 1;

[0062] (2) Add bisphenol A liquid epoxy resin, phenol-type phenolic epoxy resin, micronized dicyandiamide (particle size 5 μm), modified imidazole, and graphene to a reaction kettle, heat up to 75 °C, stir for 90 min, and then grind the mixture three times on a three-roll mill to obtain Component 2;

[0063] (3) Mix Component 1 and Component 2 in a reaction kettle at a temperature of 80 °C and stir for 30 min to obtain a graphene epoxy resin composition.

[0064] Secondly, preparation of prepreg.

[0065] Specifically, it includes: (1) Prepare an impregnating resin film of the above-prepared graphene epoxy resin composition on a film coater; (2) Impregnate the prepared impregnating resin film on fibers on a prepreg machine, and the fibers are carbon fiber T700 grade.

[0066] Finally, preparation of composite material.

[0067] Cut the above-prepared prepreg, lay it on a mold, and cure it by autoclave process at a curing temperature of 140 °C, a time of 60 min, and a curing pressure of 6 bar.

[0068] Example 2

[0069] The graphene epoxy resin composite material comprises the following raw materials in mass fractions:

[0070] 40 parts of bisphenol A solid epoxy resin;

[0071] 28 parts of bisphenol A liquid epoxy resin;

[0072] 10 parts of toughening resin;

[0073] 10 parts of phenol-type phenolic epoxy resin;

[0074] 2 parts of graphene;

[0075] 7 parts of micron-sized dicyandiamide:

[0076] 3 parts of accelerator (modified urea).

[0077] The viscosity of the bisphenol A liquid epoxy resin in this example is 10000 cp.

[0078] The viscosity of the phenol-type phenolic epoxy resin in this example is 20000 cp.

[0079] The particle size of the curing agent micron-sized dicyandiamide is 10 μm.

[0080] In this example, the preparation method of the graphene epoxy resin composite material comprises the following steps.

[0081] Firstly, preparation of resin composition.

[0082] (1) Add bisphenol A solid epoxy resin and rubber-type toughening agent to a reaction kettle, under vacuum conditions, heat up to 120 °C and stir for 40 min to obtain Component 1;

[0083] (2) Add bisphenol A liquid epoxy resin, phenol novolac epoxy resin, micronized dicyandiamide (particle size 5 μm), modified urea, and graphene into a reaction kettle, heat up to 75 °C, stir for 80 min, and then grind the mixture three times on a three-roll mill to obtain Component Two;

[0084] (3) Mix Component One and Component Two in a reaction kettle at a temperature of 80 °C and stir for 30 min to obtain a graphene epoxy resin composition.

[0085] Secondly, preparation of prepreg.

[0086] Specifically: (1) Prepare an impregnated resin film from the above-prepared graphene epoxy resin composition on a film coater; (2) Impregnate the prepared film on fibers on a prepreg machine, and the fibers are carbon fiber T700 grade.

[0087] Finally, preparation of composite material.

[0088] Cut the above-prepared prepreg, lay it on a mold, and cure it by autoclave process at a curing temperature of 140 °C, a time of 60 min, and a curing pressure of 6 bar.

[0089] Example 3

[0090] The graphene epoxy resin composite material comprises the following raw materials in mass fractions:

[0091] 35 parts of bisphenol A solid epoxy resin;

[0092] 25 parts of bisphenol A liquid epoxy resin;

[0093] 8 parts of toughening resin;

[0094] 15 parts of phenol novolac epoxy resin;

[0095] 5 parts of graphene;

[0096] 9 parts of micronized dicyandiamide:

[0097] 3 parts of accelerator (modified amine).

[0098] The viscosity of the bisphenol A liquid epoxy resin of the present invention is 20000 cp.

[0099] The viscosity of the phenol novolac epoxy resin of the present invention is 20000 cp.

[0100] The particle size of the curing agent micronized dicyandiamide is 10 μm.

[0101] In this example, the preparation method of the graphene epoxy resin composite material comprises the following steps.

[0102] First, preparation of the resin composition.

[0103] (1) Add bisphenol A solid epoxy resin and a nano-particle toughening agent to a reaction kettle. Under vacuum conditions, heat up to 130 °C and stir for 40 min to obtain Component 1.

[0104] (2) Add bisphenol A liquid epoxy resin, phenol-type phenolic epoxy resin, micronized dicyandiamide (particle size 5 μm), modified amine, and graphene to a reaction kettle. Heat up to 80 °C and stir for 90 min. Then grind the mixture three times on a three-roll mill to obtain Component 2.

[0105] (3) Mix Component 1 and Component 2 in a reaction kettle at a temperature of 80 °C and stir for 30 min to obtain a graphene epoxy resin composition.

[0106] Secondly, preparation of the prepreg.

[0107] The specific process is as follows: (1) Prepare an impregnated resin film from the above-prepared graphene epoxy resin composition on a film coater; (2) Lay the prepared film on fibers for impregnation on a prepreg machine, and the fibers are glass fibers.

[0108] Finally, preparation of the composite material.

[0109] Cut the above-prepared prepreg, lay it on a mold, and cure it using an autoclave process. The curing temperature is 140 °C, the time is 60 min, and the curing pressure is 6 bar.

[0110] Example 4

[0111] The graphene epoxy resin composite material comprises the following raw materials in mass fractions:

[0112] 42 parts of bisphenol A solid epoxy resin;

[0113] 25 parts of bisphenol A liquid epoxy resin;

[0114] 5 parts of toughening resin;

[0115] 12 parts of phenol-type phenolic epoxy resin;

[0116] 5 parts of graphene;

[0117] 8 parts of micronized dicyandiamide:

[0118] 3 parts of accelerator (modified amine).

[0119] The viscosity of the bisphenol A liquid epoxy resin of the present invention is 10000 cp.

[0120] The viscosity of the phenol-type phenolic epoxy resin of the present invention is 15000 cp.

[0121] The particle size of the curing agent micronized dicyandiamide is 5 μm.

[0122] In this embodiment, the preparation method of the graphene epoxy resin composite material comprises the following steps.

[0123] First, the preparation of the resin composition.

[0124] (1) Add bisphenol A solid epoxy resin and rubber toughening agent to the reaction kettle, under vacuum conditions, heat up to 120 °C, stir for 40 min to obtain Component 1;

[0125] (2) Add bisphenol A liquid epoxy resin, phenol novolac epoxy resin, micronized dicyandiamide (particle size 5 μm), modified amine, and graphene to the reaction kettle, heat up to 80 °C, stir for 90 min, and then grind the mixture three times on a three-roll mill to obtain Component 2;

[0126] (3) Mix Component 1 and Component 2 in the reaction kettle at a temperature of 80 °C, stir for 30 min to obtain the graphene epoxy resin composition.

[0127] Secondly, the preparation of the prepreg.

[0128] The specific process is: (1) Prepare an impregnated resin film of the above-prepared graphene epoxy resin composition on a film coater; (2) Lay the prepared film on the fiber for impregnation on a prepreg machine, and the fiber is glass fiber.

[0129] Finally, the preparation of the composite material.

[0130] Cut the above-prepared prepreg, lay it on the mold, and cure it using the autoclave process, with a curing temperature of 140 °C, a time of 60 min, and a curing pressure of 6 bar.

[0131] Comparative Example 1

[0132] In this comparative example, the resin composite material is composed by mass fraction: 45 parts of bisphenol A solid epoxy resin, 20 parts of bisphenol A liquid epoxy resin, 8 parts of toughening resin, 13 parts of phenol novolac epoxy resin, 3 parts of carbon nanotubes, 8 parts of micronized dicyandiamide, and 3 parts of accelerator (modified imidazole); the rest is the same as in Example 1.

[0133] Referring to the preparation method of Example 1, a composite material is prepared.

[0134] Comparative Example 2

[0135] In this comparative example, the resin composite material is composed by mass fraction: 35 parts of bisphenol A solid epoxy resin, 25 parts of bisphenol A liquid epoxy resin, 8 parts of toughening resin, 15 parts of phenol-type phenolic epoxy resin, 5 parts of carbon nanotubes, 9 parts of micron-grade dicyandiamide, and 3 parts of accelerator (modified amine); the rest is the same as in Example 3.

[0136] Referring to the preparation method of Example 3, a composite material was prepared.

[0137] During the testing process, using the existing performance testing methods, the parameters of the composite materials prepared in Examples 1 to 4 and the prepregs of Comparative Example 1 and the prepregs of Comparative Example 2 were measured. The test results are shown in Table 1.

[0138] Table 1 Comparison table of test results

[0139]

[0140]

[0141] It can be seen from Table 1 that: compared with Comparative Example 1, for the composite material prepared after using graphene in Example 1, the tensile strength, flexural strength, and interlaminar shear strength are increased, the surface resistance is reduced, and the conductivity is high.

[0142] It can be seen from Table 1 that: compared with Comparative Example 2, for the composite material prepared after using graphene in Example 3, the tensile strength, flexural strength, and interlaminar shear strength are increased, the surface resistance is reduced, and the conductivity is high.

Claims

1. A graphene epoxy resin composite material, characterized in that, it is composed of the following raw materials in parts by mass: 45 parts of bisphenol A solid epoxy resin; 20 parts of bisphenol A liquid epoxy resin; 8 parts of toughening agent; 13 parts of phenol-type phenolic epoxy resin; 3 parts of graphene; 8 parts of curing agent; 3 parts of accelerator; the accelerator is modified imidazole; the curing agent is micro-powdered dicyandiamide with a particle size of 5 μm; the viscosity of the bisphenol A liquid epoxy resin is 20000 cp; the viscosity of the phenol-type phenolic epoxy resin is 15000 cp; the toughening agent is a rubber-type toughening agent; The preparation method of the graphene epoxy resin composite material is as follows: 1) Prepare each raw material according to the parts by mass described; 2) Mix the bisphenol A solid epoxy resin and the toughening agent, and under vacuum conditions, heat up to 130 °C and stir for 40 min to obtain Component 1; 3) Mix the bisphenol A liquid epoxy resin, phenol-type phenolic epoxy, curing agent, accelerator, and graphene, heat up to 75 °C, stir for 90 min, and then grind the mixture three times on a three-roll grinder to obtain Component 2; 4) Mix Component 1 and Component 2 at a temperature of 80 °C and stir for 30 min to obtain a graphene epoxy resin composition; 5) Prepare an impregnated resin film from the obtained graphene epoxy resin composition on a film coater; 6) Lay the obtained impregnated resin film on the fiber on a prepreg machine for impregnation to obtain a prepreg; the fiber is carbon fiber T700 grade; 7) Cut the obtained prepreg, lay it on a mold, and cure it using a autoclave process to obtain a composite material; the curing temperature is 140 °C, the time is 60 min, and the curing pressure is 6 bar.

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