A biomass activated carbon modified carbon fiber sizing agent, a preparation method and application thereof

Abstract

The present application provides a kind of biomass activated carbon modified carbon fiber sizing agent, preparation method and application, it is related to carbon fiber sizing agent field.The preparation method of the biomass activated carbon modified carbon fiber sizing agent includes the following steps: preparation sheet porous activated carbon, mixed preparation agent.The preparation method of the biomass activated carbon modified carbon fiber sizing agent effectively adapts to the characteristics of existing carbon fiber sizing agent by preparing specific biomass activated carbon, improves its wetting property at the same time, simultaneously improves the interface chemical bonding ability and load transfer efficiency of carbon fiber, improves the interface interaction of carbon fiber and resin material matrix, promotes carbon fiber to build ordered interface reinforcing structure in resin-based composite material.

Description

Technical Field

[0001] This invention relates to the field of carbon fiber sizing agents, and in particular to a biomass activated carbon modified carbon fiber sizing agent, its preparation method, and its application. Background Technology

[0002] Carbon fibers have high surface inertness, small specific surface area, and lack active functional groups. When used to prepare carbon fiber-reinforced resin matrix composites, this leads to low interfacial bonding strength between the carbon fibers and the resin matrix, easily causing interlaminar delamination and stress concentration. To compensate for these defects, existing technologies typically use sizing agents to treat the carbon fibers. Traditional sizing agents often use synthetic polymers such as polyurethane and polyacrylate, which can improve wettability but are difficult to simultaneously improve interfacial chemical bonding ability and load transfer efficiency.

[0003] In recent years, carbon nanomaterials (such as carbon nanotubes and graphene) have been attempted for sizing modification of carbon fibers, but problems such as difficulty in dispersion, high cost, and significant environmental risks exist, making them unsuitable for large-scale industrial production. Biomass-derived activated carbon has advantages such as renewability, low cost, and tunable structure, but conventional biomass activated carbon is in the form of disordered microporous particles with an excessively large specific surface area and chaotic surface polar functional groups. It cannot be adapted to the sizing properties on the carbon fiber surface, and its use can easily cause resin crosslinking quenching or phase separation, ultimately resulting in the inability to effectively construct an ordered interfacial reinforcement structure, which seriously affects the performance of carbon fiber reinforced resin matrix composites.

[0004] Based on this, a method for preparing a biomass activated carbon modified carbon fiber sizing agent is provided. By preparing specific biomass activated carbon, it can effectively adapt to the characteristics of existing carbon fiber sizing agents. While improving its wettability, it can simultaneously enhance the interfacial chemical bonding ability and load transfer efficiency of carbon fibers, improve the interfacial interaction between carbon fibers and resin matrix, and promote the construction of an ordered interfacial reinforcement structure of carbon fibers in resin matrix composites. This method has important technical significance and research value. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a method for preparing a biomass activated carbon modified carbon fiber sizing agent. By preparing specific biomass activated carbon, it effectively adapts to the characteristics of existing carbon fiber sizing agents, improving its wettability while simultaneously enhancing the interfacial chemical bonding ability and load transfer efficiency of carbon fibers, improving the interfacial interaction between carbon fibers and the resin matrix, and promoting the construction of an ordered interfacial reinforcement structure of carbon fibers in resin-based composite materials.

[0006] The present invention also provides a biomass activated carbon modified carbon fiber sizing agent prepared by the aforementioned method.

[0007] The present invention also provides the application of the biomass activated carbon modified carbon fiber sizing agent.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A method for preparing a biomass activated carbon modified carbon fiber sizing agent includes the following steps: preparing sheet-like porous activated carbon and a mixed formulation; The method for preparing sheet-like porous activated carbon involves the following steps: sorghum stalks with a moisture content of <0.5 wt% are washed, carbonized at high temperature under inert gas protection, and then cooled; subsequently activated in air and cooled again; finally, acid-washed, washed with water until neutral, and dried to obtain a specific surface area of ​​1000-1300 m². 2 Flake-shaped porous activated carbon with an O / C atomic ratio of 0.08-0.12 per g. The method for preparing the mixed formulation is to mix a carbon fiber sizing agent with a solid content of 3-5 wt% with sheet-like porous activated carbon evenly to obtain a biomass activated carbon modified carbon fiber sizing agent. The resin matrix of the carbon fiber sizing agent is epoxy resin or vinyl resin.

[0009] Furthermore, in the preparation of sheet-like porous activated carbon, the high-temperature carbonization involves placing the cleaned sorghum stalk core in an inert gas environment, controlling the gauge pressure of the inert gas to be 0.05-0.1 bar, raising the temperature to 1000-1300℃, holding the temperature for carbonization for 40-60 minutes, and then cooling to complete the high-temperature carbonization treatment.

[0010] Furthermore, in the preparation of sheet-like porous activated carbon, air activation involves placing the high-temperature carbonized sorghum stalk core in an air atmosphere, heating it to 200-400℃ under normal pressure, holding it at that temperature for 40-80 minutes, and then cooling it to complete the air activation.

[0011] Preferably, in the preparation of the sheet-like porous activated carbon, the heating rate of high-temperature carbonization is 1-3℃ / min; The heating rate for air activation is 1-5℃ / min.

[0012] Preferably, in the preparation of sheet-like porous activated carbon, acid washing is carried out using dilute hydrochloric acid with a concentration of 1-3 mol / L.

[0013] Preferably, in the mixed formulation, the amount of sheet-like porous activated carbon added is controlled to be 0.01-1 wt% in the mixture of carbon fiber sizing agent and sheet-like porous activated carbon.

[0014] Furthermore, in the preparation of the sheet-like porous activated carbon, the cleaned sorghum stalk core is prepared by the following method: the sorghum stalk core is completely immersed in deionized water, heated to 60-80℃, and soaked for 1-2 hours. The solid matter is then separated and collected. The solid matter is washed and dried to obtain the cleaned sorghum stalk core.

[0015] A biomass activated carbon modified carbon fiber sizing agent is prepared using the aforementioned preparation method.

[0016] An application of a biomass activated carbon modified carbon fiber sizing agent, wherein the aforementioned biomass activated carbon modified carbon fiber sizing agent is used to sizing carbon fiber; and the amount of biomass activated carbon modified carbon fiber sizing agent adhering to the surface of carbon fiber after sizing is controlled to be 0.8-1.2 wt%.

[0017] A carbon fiber reinforced resin matrix composite material is prepared using carbon fibers with the aforementioned biomass activated carbon modified carbon fiber sizing agent attached to their surface; and the volume percentage content of carbon fibers in the carbon fiber reinforced resin matrix composite material is controlled to be not less than 60%. The resin matrix of the carbon fiber reinforced resin matrix composite material is epoxy resin or vinyl resin.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The preparation method of the biomass activated carbon modified carbon fiber sizing agent of the present invention uses cleaned sorghum stalk core as raw material precursor. By controlling the process parameters in the high-temperature carbonization and air activation process, precise pyrolysis path control (directional carbonization and controllable oxidation activation) is achieved. The resulting sheet-like porous activated carbon has a sheet-like morphology, in-plane interconnected micro-mesopores, rich in oxygen functional groups and graphene-like locally ordered structure, which can effectively adapt to the characteristics of existing carbon fiber sizing agents. The sheet-like porous activated carbon also has a high specific surface area (1000-1300m²). 2 With its high oxygen content (O / C atomic ratio of 0.08-0.12), excellent dispersion stability, and interfacial anchoring ability, it can be used as a highly efficient "structure-function" dual-directed sizing agent dispersed in epoxy resin-based or vinyl resin-based sizing agents. It can improve the wettability of carbon fibers while simultaneously enhancing the interfacial chemical bonding ability and load transfer efficiency of carbon fibers, improving the interfacial interaction between carbon fibers and the resin matrix, and promoting the construction of an ordered interfacial reinforcement structure of carbon fibers in resin-based composite materials.

[0019] (2) The preparation method of the biomass activated carbon modified carbon fiber sizing agent of the present invention uses the core of agricultural crop sorghum stalk as raw material to prepare sheet-like porous activated carbon, which can save resources and protect the natural environment at the same time, and can effectively save preparation costs; moreover, its preparation method is simple and easy to implement, the preparation process is easy to control, the production efficiency is high, and it is conducive to large-scale industrial application.

[0020] (3) The biomass activated carbon modified carbon fiber sizing agent of the present invention can effectively improve the interlaminar shear strength of the resin-based composite material prepared by dispersing the prepared sheet-like porous activated carbon in a conventional carbon fiber sizing agent; compared with the existing conventional carbon fiber sizing agent, the interlaminar shear strength improvement rate can reach 12.4%. Attached Figure Description

[0021] Figure 1 Transmission electron microscopy (TEM) image of the sheet-like porous activated carbon prepared in Example 1.

[0022] Figure 2 The image shows the X-ray photoelectron spectroscopy (XPS) spectrum of the sheet-like porous activated carbon prepared in Example 1.

[0023] Figure 3 Nitrogen adsorption-desorption curves and pore size distribution of the sheet-like porous activated carbon prepared in Example 1. Detailed Implementation

[0024] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described. It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, "first," "second," etc., are used to distinguish similar objects and are not used to describe a particular order or sequence. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] This invention provides a method for preparing a biomass activated carbon modified carbon fiber sizing agent, comprising the following steps: Step S01: Preparation of sheet-like porous activated carbon: The cleaned sorghum stalk core is carbonized at high temperature under inert gas protection, cooled and then activated by air, and finally acid washed to obtain sheet-like porous activated carbon. Step S02, Mixing formulation: After uniformly mixing the obtained sheet-like porous activated carbon with the carbon fiber sizing agent, a biomass activated carbon modified carbon fiber sizing agent is obtained.

[0027] Furthermore, the specific method for step S01 (i.e., preparing sheet-like porous activated carbon) is as follows: (1) Precursor pretreatment: sorghum stalk cores are obtained by peeling sorghum stalk cores. The sorghum stalk cores are completely immersed in deionized water, heated to 60-80℃, and soaked for 1-2 hours. The solids are then separated and collected. The solids are washed with deionized water and anhydrous ethanol 3-5 times each to remove water-soluble inorganic salts. The solids are dried at 60-80℃ until the water content is less than 0.5wt% to obtain the precursor.

[0028] The process involves completely immersing the sorghum stalk core in deionized water, ensuring that the volume of the deionized water is at least completely submerged in the sorghum stalk core. During this process, the volume of the deionized water must be at least twice the volume of the sorghum stalk core; for example, it can be 2, 3, or 4 times.

[0029] (2) High-temperature carbonization: The precursor is placed in a tube furnace, and the air in the tube furnace is completely replaced with nitrogen. Nitrogen is continuously supplied and the nitrogen pressure in the tube furnace is controlled at 0.05-0.1 bar (gauge pressure). In the nitrogen atmosphere, the temperature is raised to 1000-1300℃ at a heating rate of 1-3℃ / min. After carbonization at this temperature for 40-60 minutes, the temperature is naturally cooled and the nitrogen supply is stopped to obtain the carbide.

[0030] (3) Air activation: The carbide is heated to 200-400℃ in an air atmosphere under normal pressure at a heating rate of 1-5℃ / min, and activated for 40-80min. After natural cooling, the activated material is obtained. The activated material is washed with 50-100 times its weight of dilute hydrochloric acid (concentration of 1-3mol / L), then washed with deionized water until neutral, and dried to obtain a specific surface area of ​​1000-1300m². 2 Flake-shaped porous activated carbon with an O / C atomic ratio of 0.08-0.12 per g.

[0031] Furthermore, the specific method for step S02 (i.e., the mixed formulation) is as follows: The biomass activated carbon modified carbon fiber sizing agent is prepared by mixing the obtained sheet-like porous activated carbon with a solid content of 3-5 wt% evenly at an addition amount of 0.01-1 wt% of sheet-like porous activated carbon.

[0032] Preferably, the amount of sheet-like porous activated carbon added is 0.01-0.1 wt%; more preferably, the amount of sheet-like porous activated carbon added is 0.02-0.03 wt%.

[0033] The resin matrix of the carbon fiber sizing agent is epoxy resin or vinyl resin (i.e., the carbon fiber sizing agent is epoxy resin-based carbon fiber sizing agent or vinyl resin-based carbon fiber sizing agent). Preferably, the carbon fiber sizing agent is commercially available Zhuben Oil Sizing Agent (brand name TX-734-SGD-TS) or Zhongfang Haitian Sizing Agent (brand name 1666).

[0034] This invention also provides a biomass activated carbon modified carbon fiber sizing agent prepared by the aforementioned preparation method.

[0035] This invention also provides the application of the biomass activated carbon modified carbon fiber sizing agent, including the following steps: sizing the carbon fiber with the biomass activated carbon modified carbon fiber sizing agent; controlling the sizing temperature at 25-35℃ and the pressure of the sizing roller at 1-3 bar during the sizing process; after the sizing process, the amount of biomass activated carbon modified carbon fiber sizing agent adhering to the carbon fiber surface is 0.8-1.2 wt%; and winding up the fibers after the sizing process.

[0036] This invention also provides a carbon fiber reinforced resin matrix composite material prepared using carbon fibers with the biomass activated carbon modified carbon fiber sizing agent attached to their surface, wherein the volume percentage content of carbon fibers in the carbon fiber reinforced resin matrix composite material is not less than 60%; The resin matrix of the carbon fiber reinforced resin matrix composite material is epoxy resin or vinyl resin.

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described below in conjunction with some specific embodiments.

[0038] Example 1 This embodiment provides a method for preparing a biomass activated carbon modified carbon fiber sizing agent, the specific steps of which are as follows: 1. Preparation of sheet-like porous activated carbon (1) Precursor pretreatment: sorghum stalk cores were obtained by peeling the sorghum stalk cores. The sorghum stalk cores were completely immersed in 3 times the volume of deionized water, heated to 70°C, and kept soaking for 1.5 h. The solids were then separated and collected. The solids were washed 3 times each with deionized water and anhydrous ethanol, and dried at 75°C until the water content was 0.3 wt% to obtain the precursor.

[0039] (2) High-temperature carbonization: The precursor is placed in a tube furnace, and the air in the tube furnace is completely replaced with nitrogen. Nitrogen is continuously supplied and the nitrogen pressure in the tube furnace is controlled at 0.06 bar (gauge pressure). In the nitrogen atmosphere, the temperature is raised to 1300℃ at a heating rate of 3℃ / min. After carbonization for 50 minutes, the temperature is naturally cooled and the nitrogen supply is stopped to obtain the carbide.

[0040] (3) Air activation: The carbides were activated in an air atmosphere (the tube furnace was connected to the atmosphere) under normal pressure. The tube furnace was heated to 300℃ at a heating rate of 4℃ / min and held for 60min. After natural cooling, the activated material was obtained. The activated material was washed with 50 times its weight of dilute hydrochloric acid (concentration of 2mol / L), then washed with sufficient deionized water until neutral, and dried to obtain a specific surface area of ​​1200m². 2 / g, sheet-like porous activated carbon with an O / C atomic ratio of 0.1.

[0041] Transmission electron microscopy (TEM) images of the aforementioned prepared sheet-like porous activated carbon are shown below. Figure 1 As shown, Figure 1 The smaller images are magnified portions of the larger images, showing that the sheet-like porous activated carbon has a two-dimensional morphology, exhibiting a sheet-like porous graphene-like structure with randomly distributed micropores and mesopores. The X-ray photoelectron spectroscopy (XPS) spectrum of the aforementioned prepared sheet-like porous activated carbon is shown below. Figure 2 As shown in the figure, the sheet-like porous activated carbon contains three elements: C, O, and N. The nitrogen adsorption-desorption curves and pore size distribution of the aforementioned prepared sheet-like porous activated carbon are shown in the figure. Figure 3 As shown, the sheet-like porous activated carbon contains abundant micropores and mesopores.

[0042] 2. Mixed formulations Commercially available carbon fiber sizing agent was diluted to a solid content of 4 wt%, and 0.02 wt% of sheet-like porous activated carbon was added. The resulting sheet-like porous activated carbon was then mixed evenly with the diluted carbon fiber sizing agent to obtain a biomass activated carbon modified carbon fiber sizing agent.

[0043] Among them, the commercially available carbon fiber sizing agent is Zhuben Oil Sizing Agent (surfactant for fiber filament), brand name TX-734-SGD-TS, and manufacturer is Zhuben Oil (Suzhou) Co., Ltd.

[0044] This embodiment also provides a biomass activated carbon modified carbon fiber sizing agent prepared by the aforementioned preparation method.

[0045] This embodiment also provides the application of the biomass activated carbon modified carbon fiber sizing agent, including the following steps: using the biomass activated carbon modified carbon fiber sizing agent to sizing T700 carbon fiber; controlling the sizing temperature at 30℃ and the pressure of the sizing roller at 2 bar during the sizing process; after the sizing process, the amount of biomass activated carbon modified carbon fiber sizing agent adhering to the carbon fiber surface is 1.1wt%; after the sizing process, winding up the fibers.

[0046] Carbon fiber reinforced epoxy resin composite material was prepared using T700 carbon fiber with biomass activated carbon modified carbon fiber sizing agent attached to its surface, and the volume fraction of carbon fiber in the composite material was controlled to be 60%. The interlaminar shear strength of the carbon fiber reinforced epoxy resin composite material was tested and found to be 70.4 MPa. Compared with the composite material prepared by treating carbon fiber with conventional sizing agent in Comparative Example 1, the interlaminar shear strength was increased by 10.52%.

[0047] Example 2 This embodiment provides a method for preparing a biomass activated carbon modified carbon fiber sizing agent, the specific steps of which are as follows: 1. Preparation of sheet-like porous activated carbon (1) Precursor pretreatment: sorghum stalk cores were obtained by peeling the sorghum stalk cores. The sorghum stalk cores were completely immersed in 2.5 times the volume of deionized water, heated to 65°C, and kept soaking for 1.5 hours. The solids were then separated and collected. The solids were washed with deionized water and anhydrous ethanol alternately 4 times each, and dried at 75°C until the water content was 0.2 wt% to obtain the precursor.

[0048] (2) High-temperature carbonization: The precursor is placed in a tube furnace, and the air in the tube furnace is completely replaced with nitrogen. Nitrogen is continuously supplied and the nitrogen pressure in the tube furnace is controlled at 0.08 bar (gauge pressure). In the nitrogen atmosphere, the temperature is raised to 1100℃ at a heating rate of 1.5℃ / min. After carbonization for 50 minutes, the temperature is naturally cooled and the nitrogen supply is stopped to obtain the carbide.

[0049] (3) Air activation: The carbides were activated in an air atmosphere (the tube furnace was connected to the atmosphere) under normal pressure. The tube furnace was heated to 350°C at a heating rate of 2°C / min and held for 50 min. After natural cooling, the activated material was obtained. The activated material was washed with 50 times its weight of dilute hydrochloric acid (concentration of 2 mol / L), then washed with sufficient deionized water until neutral, and dried to obtain a specific surface area of ​​1050 m². 2 / g, sheet-like porous activated carbon with an O / C atomic ratio of 0.08.

[0050] 2. Mixed formulations Commercially available carbon fiber sizing agent was diluted to a solid content of 4 wt%. The amount of sheet-like porous activated carbon added was 0.025 wt%. The resulting sheet-like porous activated carbon was mixed evenly with the diluted carbon fiber sizing agent to obtain a biomass activated carbon modified carbon fiber sizing agent.

[0051] Among them, the commercially available carbon fiber sizing agent is Zhuben Oil Sizing Agent (surfactant for fiber filament), brand name TX-734-SGD-TS, and manufacturer is Zhuben Oil (Suzhou) Co., Ltd.

[0052] This embodiment also provides a biomass activated carbon modified carbon fiber sizing agent prepared by the aforementioned preparation method.

[0053] This embodiment also provides the application of the biomass activated carbon modified carbon fiber sizing agent, including the following steps: using the biomass activated carbon modified carbon fiber sizing agent to sizing T700 carbon fiber; controlling the sizing temperature at 28°C and the pressure of the sizing roller at 2.2 bar during the sizing process; after the sizing process, the amount of biomass activated carbon modified carbon fiber sizing agent adhering to the carbon fiber surface is 1.05 wt%; after the sizing process, winding up the fibers.

[0054] Carbon fiber reinforced epoxy resin composite material was prepared using T700 carbon fiber with biomass activated carbon modified carbon fiber sizing agent attached to its surface, and the volume fraction of carbon fiber in the composite material was controlled to be 60%. The interlaminar shear strength of the carbon fiber reinforced epoxy resin composite material was tested and found to be 71.6 MPa. Compared with the composite material prepared by treating carbon fiber with conventional sizing agent in Comparative Example 1, the interlaminar shear strength was increased by 12.4%.

[0055] Example 3 This embodiment provides a method for preparing a biomass activated carbon modified carbon fiber sizing agent, the specific steps of which are as follows: 1. Preparation of sheet-like porous activated carbon (1) Precursor pretreatment: sorghum stalk cores were obtained by peeling the sorghum stalk cores. The sorghum stalk cores were completely immersed in 3 times the volume of deionized water, heated to 70°C, and kept at the temperature for 1 hour. The solids were then separated and collected. The solids were washed with deionized water and anhydrous ethanol alternately 4 times each, and dried at 70°C until the water content was 0.3wt% to obtain the precursor.

[0056] (2) High-temperature carbonization: The precursor is placed in a tube furnace, and the air in the tube furnace is completely replaced with nitrogen. Nitrogen is continuously supplied and the nitrogen pressure in the tube furnace is controlled at 0.08 bar (gauge pressure). In the nitrogen atmosphere, the temperature is raised to 1250°C at a heating rate of 2.5°C / min. After carbonization for 40 minutes, the temperature is naturally cooled and the nitrogen supply is stopped to obtain the carbide.

[0057] (3) Air activation: The carbides were activated in an air atmosphere under normal pressure by heating the tubular furnace to 280°C at a heating rate of 3°C / min, holding the temperature for 60 min, and then naturally cooling to obtain the activated material. The activated material was washed with 60 times its weight of dilute hydrochloric acid (concentration of 1.5 mol / L), then washed with sufficient deionized water until neutral, and dried to obtain a specific surface area of ​​1250 m². 2 / g, sheet-like porous activated carbon with an O / C atomic ratio of 0.11.

[0058] 2. Mixed formulations Commercially available carbon fiber sizing agent was diluted to a solid content of 3.5 wt%. The amount of sheet-like porous activated carbon added was 0.02 wt%. The resulting sheet-like porous activated carbon was mixed evenly with the diluted carbon fiber sizing agent to obtain a biomass activated carbon modified carbon fiber sizing agent.

[0059] Among them, the commercially available carbon fiber sizing agent is Zhongfang Haitian sizing agent, brand number 1666, and the manufacturer is Beijing Zhongfang Haitian New Material Technology Co., Ltd.

[0060] This embodiment also provides a biomass activated carbon modified carbon fiber sizing agent prepared by the aforementioned preparation method.

[0061] This embodiment also provides the application of the biomass activated carbon modified carbon fiber sizing agent, including the following steps: using the biomass activated carbon modified carbon fiber sizing agent to sizing T700 carbon fiber; controlling the sizing temperature at 30℃ and the pressure of the sizing roller at 1.8 bar during the sizing process; after the sizing process, the amount of biomass activated carbon modified carbon fiber sizing agent adhering to the carbon fiber surface is 0.92wt%; after the sizing process, winding up the fibers.

[0062] Carbon fiber reinforced epoxy resin composite material was prepared using T700 carbon fiber with biomass activated carbon modified carbon fiber sizing agent attached to its surface, and the volume fraction of carbon fiber in the composite material was controlled to be 60%. The interlaminar shear strength of the carbon fiber reinforced epoxy resin composite material was tested to be 68.6 MPa. Compared with the composite material prepared by treating carbon fiber with conventional sizing agent in Comparative Example 2, the interlaminar shear strength was increased by 9.24%.

[0063] Comparative Example 1 Commercially available bamboo oil sizing agent (brand: TX-734-SGD-TS) was diluted to a solid content of 4wt% and used as a carbon fiber sizing agent. This carbon fiber sizing agent was used to sizing T700 carbon fiber: the sizing temperature was controlled at 30℃, the pressure of the sizing roller was 1.8 bar, and the amount of carbon fiber sizing agent adhering to the carbon fiber surface after sizing was 0.95wt%. After sizing, the fibers were wound up.

[0064] Carbon fiber reinforced epoxy resin composite material was prepared using T700 carbon fiber with carbon fiber sizing agent attached to its surface, and the volume fraction of carbon fiber in the composite material was controlled to be 60%. The interlaminar shear strength of the carbon fiber reinforced epoxy resin composite material of Comparative Example 1 was tested to be 63.7 MPa.

[0065] Comparative Example 2 Commercially available Zhongfang Haitian sizing agent (brand: 1666) was diluted to a solid content of 3.5 wt% and used as a carbon fiber sizing agent. This carbon fiber sizing agent was used to sizing T700 carbon fiber: the sizing temperature was controlled at 30℃, the pressure of the sizing roller was 1.8 bar, and the amount of carbon fiber sizing agent adhering to the carbon fiber surface after sizing was 0.78 wt%. After sizing, the fibers were wound up.

[0066] Carbon fiber reinforced epoxy resin composite material was prepared using T700 carbon fiber with carbon fiber sizing agent attached to its surface, and the volume fraction of carbon fiber in the composite material was controlled to be 60%. The interlaminar shear strength of the carbon fiber reinforced epoxy resin composite material of Comparative Example 2 was tested to be 62.8 MPa.

[0067] Unless otherwise stated, all percentages used in this invention are mass percentages.

[0068] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a biomass activated carbon modified carbon fiber sizing agent, characterized in that, The process includes the following steps: preparing sheet-like porous activated carbon and mixing formulations; The method for preparing sheet-like porous activated carbon involves carbonizing cleaned sorghum stalks with a moisture content of <0.5wt% at high temperature under inert gas protection, followed by cooling. Then, after air activation in an air atmosphere, it is cooled; finally, after acid washing, it is washed with water until neutral, and dried to obtain a specific surface area of ​​1000-1300 m². 2 Flake-shaped porous activated carbon with an O / C atomic ratio of 0.08-0.12 per g. The method for preparing the mixed formulation is to mix a carbon fiber sizing agent with a solid content of 3-5 wt% with sheet-like porous activated carbon evenly to obtain a biomass activated carbon modified carbon fiber sizing agent. The resin matrix of the carbon fiber sizing agent is epoxy resin or vinyl resin.

2. The preparation method of the biomass activated carbon modified carbon fiber sizing agent according to claim 1, characterized in that, In the preparation of sheet-like porous activated carbon, high-temperature carbonization involves placing the cleaned sorghum stalk cores in an inert gas environment, controlling the gauge pressure of the inert gas to be 0.05-0.1 bar, raising the temperature to 1000-1300℃, holding the temperature for carbonization for 40-60 minutes, and then cooling to complete the high-temperature carbonization treatment.

3. The preparation method of the biomass activated carbon modified carbon fiber sizing agent according to claim 1, characterized in that, In the preparation of sheet-like porous activated carbon, air activation involves placing the high-temperature carbonized sorghum stalk core in an air atmosphere, heating it to 200-400℃ under normal pressure, holding it at that temperature for 40-80 minutes, and then cooling it to complete the air activation.

4. The preparation method of the biomass activated carbon modified carbon fiber sizing agent according to claim 1, characterized in that, In the preparation of sheet-like porous activated carbon, the heating rate of high-temperature carbonization is 1-3℃ / min; The heating rate for air activation is 1-5℃ / min.

5. The method for preparing the biomass activated carbon modified carbon fiber sizing agent according to claim 1, characterized in that, In the preparation of the sheet-like porous activated carbon, acid washing is carried out using dilute hydrochloric acid with a concentration of 1-3 mol / L.

6. The method for preparing the biomass activated carbon modified carbon fiber sizing agent according to claim 1, characterized in that, In the mixed formulation, the amount of sheet-like porous activated carbon added is controlled to be 0.01-1 wt% in the mixture of carbon fiber sizing agent and sheet-like porous activated carbon.

7. The preparation method of the biomass activated carbon modified carbon fiber sizing agent according to claim 1, characterized in that, In the preparation of the sheet-like porous activated carbon, the cleaned sorghum stalk core is prepared by the following method: the sorghum stalk core is completely immersed in deionized water, heated to 60-80℃, and soaked for 1-2 hours. The solid matter is then separated and collected. The solid matter is washed and dried to obtain the cleaned sorghum stalk core.

8. A biomass activated carbon modified carbon fiber sizing agent, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. An application of a biomass activated carbon modified carbon fiber sizing agent, characterized in that, The biomass activated carbon modified carbon fiber sizing agent as described in claim 8 is used to sizing the carbon fiber; and the amount of biomass activated carbon modified carbon fiber sizing agent adhering to the carbon fiber surface after the sizing treatment is controlled to be 0.8-1.2 wt%.

10. A carbon fiber reinforced resin matrix composite material, characterized in that, The carbon fiber is prepared by coating the surface of the biomass activated carbon modified carbon fiber sizing agent as described in claim 8; and the volume percentage content of carbon fiber in the carbon fiber reinforced resin matrix composite is controlled to be not less than 60%. The resin matrix of the carbon fiber reinforced resin matrix composite material is epoxy resin or vinyl resin.

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