阅读说明：本技术 提高复合材料环氧树脂基体导电性的制备方法 (Preparation method for improving conductivity of composite material epoxy resin matrix ) 是由 杜斌 赵玉顺 时宇 杨克荣 张松 陶加贵 刘屿 于 2020-06-22 设计创作，主要内容包括：本发明涉及一种提高复合材料环氧树脂基体导电性的制备方法,具体包括以下步骤：S1按比例称取原材料；S2将碳纤维粉放入硝酸中,再用纯水洗涤碳纤维粉以去除硝酸,再放入真空干燥箱中进行干燥处理；S3将环氧树脂和甲基四氢邻苯二甲酸酐固化剂放入烧瓶中搅拌,搅拌之后在烧瓶中加入DMP-30,S4将金属模具的表面用酒精进行处理,后放入真空干燥箱中进行干燥处理,并将金属模具的表面喷涂脱模剂,再次放入真空干燥箱中进行硫化处理；S5将碳纤维粉和环氧树脂基体的混合液加入球磨机中进行充分混合,再将充分混合后的混合液导入硫化后的金属模具中等待成型,成型后进行脱模处理,获得改性后的环氧树脂基体。(The invention relates to a preparation method for improving the conductivity of a composite material epoxy resin matrix, which specifically comprises the following steps: s1, weighing the raw materials in proportion; s2, putting the carbon fiber powder into nitric acid, washing the carbon fiber powder with pure water to remove the nitric acid, and then putting the carbon fiber powder into a vacuum drying oven for drying; s3, placing epoxy resin and a methyl tetrahydrophthalic anhydride curing agent into a flask, stirring, adding DMP-30 into the flask after stirring, S4 treating the surface of a metal mold with alcohol, then placing the metal mold into a vacuum drying oven for drying, spraying a release agent on the surface of the metal mold, and placing the metal mold into the vacuum drying oven again for vulcanization; s5, adding the mixed liquid of the carbon fiber powder and the epoxy resin matrix into a ball mill for fully mixing, introducing the fully mixed liquid into a vulcanized metal mold for waiting for molding, and demolding after molding to obtain the modified epoxy resin matrix.)

1. A preparation method for improving the conductivity of a composite material epoxy resin matrix is characterized by comprising the following steps:

s1 preparation at the early stage: weighing carbon fiber powder, epoxy resin, a methyltetrahydrophthalic anhydride curing agent, a DMP-30 accelerator and nitric acid according to a proportion;

s2 treatment of carbon fiber powder: putting carbon fiber powder into nitric acid, and treating for 4-6 h in a water bath at 50-70 ℃; washing the carbon fiber powder with pure water to remove nitric acid, and drying in a vacuum drying oven for later use;

preparation of S3 epoxy resin matrix: putting epoxy resin and a methyltetrahydrophthalic anhydride curing agent into a flask, putting the flask into a magnetic stirrer, vacuumizing and stirring, carrying out water bath treatment at 50-70 ℃, adding a DMP-30 promoter into the flask after stirring for 5-15 min, and stirring again for 3-8 min to obtain an epoxy resin matrix;

s4 treatment of the metal mold: treating the surface of the metal mold with alcohol to ensure the surface to be clean and free from dirt; then putting the metal mold into a vacuum drying oven for drying treatment, taking out the metal mold, spraying a release agent on the surface of the metal mold, and then putting the metal mold into the vacuum drying oven again for vulcanization treatment;

s5 mixing treatment of carbon fiber powder and epoxy resin matrix: adding the carbon fiber powder dried in the step S2 into the epoxy resin matrix in the step S3, adding a mixed solution of the carbon fiber powder and the epoxy resin matrix into a ball mill for fully mixing, introducing the fully mixed solution into the vulcanized metal mold for waiting for molding, and demolding the metal mold after molding to obtain the modified epoxy resin matrix.

2. The preparation method for improving the conductivity of the composite material epoxy resin matrix according to claim 1, wherein the carbon fiber powder, the epoxy resin, the methyltetrahydrophthalic anhydride curing agent, the DMP-30 accelerator and the nitric acid are prepared from the following components in parts by weight: 15-20 parts of carbon fiber powder, 40-50 parts of epoxy resin, 30-40 parts of methyl tetrahydrophthalic anhydride curing agent, 0.5-2 parts of DMP-30 accelerator and 40-70 parts of nitric acid.

3. The preparation method for improving the conductivity of the composite material epoxy resin matrix according to claim 2, wherein the carbon content in the carbon fiber powder is more than 95%, and the particle diameter is less than 8 μm; the concentration of the nitric acid is 60%.

4. The preparation method for improving the conductivity of the composite material epoxy resin matrix according to claim 2, wherein the drying treatment in the step S2 is carried out at 100 ℃ for 5-7 h; the drying treatment in the step S4 is carried out at the temperature of 130 ℃ for 10-20 min; the temperature of the vulcanization treatment in the step S4 is 170 ℃, and the treatment time is 15 min.

5. The preparation method for improving the conductivity of the composite material epoxy resin matrix according to claim 3, wherein the volume ratio of the carbon fiber powder to the nitric acid in the step S2 is 1: 5; the mass ratio of the epoxy resin to the methyltetrahydrophthalic anhydride curing agent in the step S3 is 100: 85 parts by weight; the mass fraction of the DMP-30 accelerator added in the step S3 accounts for 2% of the mass fraction of the epoxy resin.

6. The preparation method for improving the conductivity of the composite material epoxy resin matrix according to claim 4, wherein the mixing time in the step S5 by using a ball mill is 10 min; the time for waiting for forming is 5 h.

7. The preparation method for improving the conductivity of the composite material epoxy resin matrix according to claim 4, wherein the water bath treatment temperature in the steps S2 and S3 is 60 ℃.

Technical Field

The invention relates to the technical field of composite materials, in particular to a preparation method for improving the conductivity of an epoxy resin matrix of a composite material.

Background

The carbon fiber composite material is widely used for manufacturing airplane parts, the use amount of the composite material in the fuselage, wings, empennage and the like of an airplane accounts for more than 50% of the self weight of the airplane, and the weight of the airplane can be reduced by more than 25% by using the composite material. Thunder is a violent gas discharge phenomenon, lightning current above 200kA can be generated at most in the discharge process, and the airplane can be struck by lightning every 3000 hours of flying according to statistics. The carbon fiber composite material has lower electrical conductivity than metal, and the material can be seriously damaged by lightning striking the composite material, so that the electrical conductivity of the carbon fiber composite material is very important to be improved. For lightning protection of composite materials, the main method is to improve the overall conductivity of the materials, and currently, researchers have proposed many methods for enhancing the conductivity of the materials. The surface of the composite material can be protected by flame spraying conductive paint or metal nets, and the protection method has the advantages of improving the conductivity of the surface of the material, but greatly increasing the mass of the airplane and causing cost increase. The carbon nano tube coated on the surface of the material can also effectively enhance the overall conductivity of the material, but the carbon nano tube is expensive and is not suitable for large-area coating on the surface of an airplane. The patent thus proposes a method for reinforcing the electrical conductivity of epoxy resins with carbon fiber powder, which has the advantage of avoiding expensive production costs and also allows a relatively small increase in the mass of the composite material.

Therefore, there is a need to develop a preparation method for improving the conductivity of the composite material epoxy resin matrix.

Disclosure of Invention

The invention aims to provide a preparation method for improving the conductivity of a composite material epoxy resin matrix.

In order to solve the technical problems, the technical scheme adopted by the invention is that the preparation method for improving the conductivity of the composite material epoxy resin matrix specifically comprises the following steps:

s1 preparation at the early stage: weighing carbon fiber powder, epoxy resin, a methyltetrahydrophthalic anhydride curing agent, a DMP-30 accelerator and nitric acid according to a proportion;

s2 treatment of carbon fiber powder: putting carbon fiber powder into nitric acid, and treating for 4-6 h in a water bath at 50-70 ℃; washing the carbon fiber powder with pure water to remove nitric acid, and drying in a vacuum drying oven for later use;

preparation of S3 epoxy resin matrix: putting epoxy resin and a methyltetrahydrophthalic anhydride curing agent into a flask, putting the flask into a magnetic stirrer, vacuumizing and stirring, carrying out water bath treatment at 50-70 ℃, adding a DMP-30 promoter into the flask after stirring for 5-15 min, and stirring again for 3-8 min to obtain an epoxy resin matrix;

s4 treatment of the metal mold: treating the surface of the metal mold with alcohol to ensure the surface to be clean and free from dirt; then putting the metal mold into a vacuum drying oven for drying treatment, taking out the metal mold, spraying a release agent on the surface of the metal mold, and then putting the metal mold into the vacuum drying oven again for vulcanization treatment;

s5 mixing treatment of carbon fiber powder and epoxy resin matrix: adding the carbon fiber powder dried in the step S2 into the epoxy resin matrix in the step S3, adding a mixed solution of the carbon fiber powder and the epoxy resin matrix into a ball mill for fully mixing, introducing the fully mixed solution into the vulcanized metal mold for waiting for molding, and demolding the metal mold after molding to obtain the modified epoxy resin matrix.

As a preferred technical scheme of the invention, the carbon fiber powder, the epoxy resin, the methyltetrahydrophthalic anhydride curing agent, the DMP-30 accelerator and the nitric acid are prepared from the following components in parts by weight: 15-20 parts of carbon fiber powder, 40-50 parts of epoxy resin, 30-40 parts of methyl tetrahydrophthalic anhydride curing agent, 0.5-2 parts of DMP-30 accelerator and 40-70 parts of nitric acid. Wherein the type of the carbon fiber powder is T700, and the type of the epoxy resin is Yueyangpetrochemical E-51.

As a preferred technical scheme of the invention, the carbon content in the carbon fiber powder is more than 95%, and the particle diameter is less than 8 μm; the concentration of the nitric acid is 60%.

As a preferable technical scheme of the invention, the drying treatment in the step S2 is performed at 100 ℃ for 5-7 h; the drying treatment in the step S4 is carried out at the temperature of 130 ℃ for 10-20 min; the temperature of the vulcanization treatment in the step S4 is 170 ℃, and the treatment time is 15 min.

As a preferable technical scheme of the invention, the volume ratio of the carbon fiber powder and the nitric acid in the step S2 is 1: 5; the mass ratio of the epoxy resin to the methyltetrahydrophthalic anhydride curing agent in the step S3 is 100: 85 parts by weight; the mass fraction of the DMP-30 accelerator added in the step S3 accounts for 2% of the mass fraction of the epoxy resin.

As a preferred embodiment of the present invention, the mixing time in the step S5 using a ball mill is 10 min; the time for waiting for forming is 5 h.

In a preferred embodiment of the present invention, the water bath treatment temperature in each of the steps S2 and S3 is 60 ℃.

By adopting the technical scheme of the invention, the beneficial effects are as follows: the preparation method for improving the conductivity of the epoxy resin matrix of the composite material improves the conductivity of the epoxy resin matrix by adding the carbon fiber, and simultaneously keeps the high performance of the epoxy resin matrix composite material, thereby being more beneficial to wide application.

Drawings

In order that the present invention may be more readily and clearly understood, reference is now made to the following detailed description of the invention taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a process flow diagram of a method of the present invention for improving the conductivity of a composite epoxy resin matrix;

FIG. 2 is a flowchart of step S3 of the method for improving the conductivity of the composite epoxy resin matrix of example 1;

FIG. 3 is a flowchart of step S4 of the method for improving the conductivity of the composite epoxy resin matrix of example 1;

fig. 4 is a flowchart of step S5 of the preparation method for improving the conductivity of the composite epoxy resin matrix in example 1 of the present invention.

Detailed Description