Bamboo fiber / graphene heat-insulating fireproof aerogel material and preparation method thereof

Abstract

This invention relates to a bamboo fiber graphene aerogel thermal insulation and fireproofing material and its preparation method, belonging to the field of functional materials technology. Addressing the problems of existing thermal insulation and fireproofing materials, such as flammability, high toxicity, high density, and high cost, this invention proposes a high-performance composite aerogel prepared using bamboo fiber as the substrate, silane coupling agent-modified graphene oxide as the reinforcing phase, combined with nano-inorganic flame retardants (aluminum hydroxide / magnesium hydroxide) and a water-based binder system, employing a freeze-drying and hot-pressing synergistic process.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, specifically to a composite aerogel thermal insulation and fireproof material prepared by combining bamboo fiber as the base material with graphene, which is suitable for thermal insulation and fireproof applications in fields such as construction, aerospace, automobiles, and electronic equipment. Background Technology

[0002] With the development of modern industry and technology, the demand for high-performance thermal insulation and fireproof materials is increasing. Traditional thermal insulation materials such as polystyrene foam and polyurethane foam have problems such as flammability and high smoke toxicity; inorganic materials such as rock wool and glass wool have good fire resistance, but they have high density, limited thermal insulation effect, and high production energy consumption.

[0003] In recent years, aerogel materials have attracted attention due to their ultra-low thermal conductivity and excellent thermal insulation properties. However, existing aerogel materials generally suffer from problems such as high production costs, poor mechanical properties, and insufficient environmental friendliness. Therefore, developing a novel aerogel material that combines high-efficiency thermal insulation, excellent fire resistance, and environmental friendliness is of significant practical importance.

[0004] Currently available materials cannot simultaneously achieve both heat insulation and fire resistance, and the sources of raw materials are limited and the costs are high. Due to limitations in production processes and output, industrial applications are not feasible. Therefore, developing a low-cost, simple-to-prepare, environmentally friendly bamboo fiber-derived carbon heat insulation and fire-resistant material that meets the development requirements of "lightweight, thin, wide, and strong" is of great significance for fire prevention and control and improving people's happiness index. Summary of the Invention

[0005] The purpose of this invention is to provide a bamboo fiber / carbon fiber thermal insulation and fireproof aerogel material and its preparation method. This electromagnetic absorbing material has unique natural micropores, large porosity, light weight, low density, and both thermal insulation and fireproof performance, which can realize large-scale production and application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A bamboo fiber / carbon fiber thermal insulation and fireproof aerogel material, wherein the thermal insulation and fireproof aerogel material is composed of bamboo fiber-derived porous carbon, and the material is three-dimensional.

[0008] A method for preparing the above-mentioned bamboo fiber / carbon fiber heat-insulating and fire-retardant aerogel material, the method comprising the following steps:

[0009] Step 1: Bamboo fiber pretreatment: After cleaning and drying, the bamboo fiber material is crushed into 10-50 mesh particles, treated with alkaline solution to remove impurities, washed with water until neutral, and dried for later use.

[0010] Step 2: Preparation of modified graphene: Disperse graphene oxide in water, add silane coupling agent KH-550, and sonicate for 30-60 minutes to obtain a uniformly dispersed modified graphene solution.

[0011] Step 3: Slurry preparation: Mix the pretreated bamboo fiber material, modified graphene solution, nano-inorganic flame retardant, binder and foaming agent in proportion and stir evenly to form a paste slurry.

[0012] Step 4: Molding and Drying: The slurry is injected into the mold and pre-frozen at -40 to -20°C for 2-6 hours using freeze-drying technology. Then, it is sublimated and dried under vacuum for 12-36 hours to form the initial aerogel product.

[0013] Step 5: Post-treatment: The aerogel sample is subjected to hot pressing treatment at a temperature of 80-120℃, a pressure of 0.5-2MPa, and a time of 10-30 minutes to improve the strength and stability of the material.

[0014] The advantages of this invention over the prior art are as follows:

[0015] (1). The present invention utilizes the synergistic effect of bamboo fiber materials and graphene to prepare aerogel materials that have both excellent thermal insulation and fire resistance properties;

[0016] (2). The use of bamboo fiber substrate reduces costs while improving the environmental friendliness and biodegradability of the material;

[0017] (3) The process of combining freeze drying and hot pressing ensures the porous structure and mechanical properties of the material;

[0018] (4) The material has high porosity, low thermal conductivity, and long fire resistance limit, and can be widely used in various high-temperature and high-risk fire situations. Detailed Implementation

[0019] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only a part of the embodiments of the invention, not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0020] Example 1

[0021] A method for preparing a bamboo fiber / carbon fiber thermal insulation and fire-retardant aerogel material, specifically comprising the following steps:

[0022] Take 40 parts of bamboo fiber and pretreat it for later use; prepare a modified graphene solution: take 15 parts of graphene oxide and disperse it in water, add an appropriate amount of KH-550, and sonicate for 45 minutes; mix the pretreated corn stalk fiber, modified graphene solution, 10 parts of nano aluminum hydroxide, 5 parts of waterborne polyurethane and 3 parts of physical foaming agent evenly; inject into a mold, pre-freeze at -30℃ for 4 hours, and vacuum dry for 24 hours; finally, hot press at 100℃ and 1MPa for 20 minutes to obtain bamboo fiber graphene aerogel thermal insulation and fireproof material sample.

[0023] The sample was tested and found to have a porosity of 92%, a thermal conductivity of 0.031 W / (m·K), a fire resistance limit of 2.5 hours, and a compressive strength of 1.2 MPa.

[0024] Example 2

[0025] A method for preparing a bamboo fiber / carbon fiber thermal insulation and fire-retardant aerogel material, specifically comprising the following steps:

[0026] Take 50 parts of bamboo fiber and pretreat it for later use; prepare modified graphene solution: take 10 parts of graphene oxide and disperse it in water, add an appropriate amount of KH-550, and sonicate for 40 minutes; mix the pretreated bamboo fiber, modified graphene solution, 8 parts of nano magnesium hydroxide, 4 parts of silica sol and 2 parts of chemical foaming agent evenly; inject into mold, pre-freeze at -25℃ for 5 hours, and vacuum dry for 30 hours; finally, hot press at 90℃ and 1.5MPa for 25 minutes to obtain bamboo fiber graphene aerogel thermal insulation and fireproof material sample.

[0027] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bamboo fiber graphene aerogel thermal insulation and fireproof material, characterized in that, It is composed of the following components in parts by weight: 30-60 parts bamboo fiber substrate, 10-25 parts modified graphene, 5-15 parts nano inorganic flame retardant, 3-10 parts binder, and 2-8 parts foaming agent.

2. The bamboo fiber graphene aerogel thermal insulation and fireproof material according to claim 1, characterized in that, The bamboo fiber substrate is selected from one or more of corn stalk fiber, bamboo fiber, wood chips or hemp fiber.

3. The bamboo fiber graphene aerogel thermal insulation and fireproof material according to claim 1, characterized in that, The modified graphene is graphene oxide that has been surface-modified with a silane coupling agent.

4. The bamboo fiber graphene aerogel thermal insulation and fireproof material according to claim 1, characterized in that, The nano-inorganic flame retardant is one or more of nano-aluminum hydroxide, nano-magnesium hydroxide, or nano-antimony trioxide.

5. The bamboo fiber graphene aerogel thermal insulation and fireproof material according to claim 1, characterized in that, The adhesive is water-based polyurethane or silica sol.

6. The bamboo fiber graphene aerogel thermal insulation and fireproof material according to claim 1, characterized in that, The foaming agent is either a physical foaming agent or a chemical foaming agent.

7. The bamboo fiber graphene aerogel thermal insulation and fireproof material according to claim 1, characterized in that, The material has a porosity of 85-98%, a thermal conductivity of ≤0.035W / (m·K), a fire resistance limit of ≥2 hours, and a compressive strength of ≥0.8MPa.

8. A method for preparing a bamboo fiber graphene aerogel thermal insulation and fireproof material as described in any one of claims 1-7, characterized in that, Includes the following steps: Bamboo fiber pretreatment: After cleaning and drying, the bamboo fiber substrate is crushed, treated with alkaline solution to remove impurities, washed with water until neutral, and dried for later use. Preparation of modified graphene: Graphene oxide is dispersed in water, silane coupling agent KH-550 is added, and ultrasonic treatment is carried out for 30-60 minutes to obtain a uniformly dispersed modified graphene solution. Slurry preparation: The pretreated bamboo fiber substrate, modified graphene solution, nano-inorganic flame retardant, binder and foaming agent are mixed in proportion and stirred evenly to form a paste slurry; Molding and drying: The slurry is injected into the mold and pre-frozen at -40 to -20°C for 2-6 hours using freeze-drying technology. Then, it is sublimated and dried under vacuum for 12-36 hours to form the initial aerogel product. Post-treatment: The aerogel sample is subjected to hot pressing at a temperature of 80-120℃, a pressure of 0.5-2MPa, and a time of 10-30 minutes to improve the strength and stability of the material.