阅读说明：本技术 一种耐高温水汽封闭膜及其制备方法 (High-temperature-resistant water vapor sealing film and preparation method thereof ) 是由 朱长伟 王姣 王建 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种耐高温水汽封闭膜及其制备方法,所述封闭膜的制备原料包括乙酸丁酯、聚甲基戊烯、聚酰亚胺、聚丙烯酸酯、改性碳纳米管、无机耐高温助剂、甲基丙烯酸缩水甘油酯和过氧化二苯甲酰。本发明通过混合、碱性接枝反应、挤出、压制、冷却、热处理回复定型、切边和收卷等工艺制得耐温性能强且水汽透过率极低的封闭膜,将该封闭膜包裹在隔热材料表面,能有效地阻隔水汽透过隔热材料,从而保证隔热效果,延长隔热材料的使用寿命；封闭膜还具有较高的耐热耐湿性能,自身使用稳定性较强。(The invention discloses a high-temperature-resistant water vapor sealing film and a preparation method thereof. According to the invention, the sealing film with strong temperature resistance and extremely low water vapor transmittance is prepared by the processes of mixing, alkaline grafting reaction, extrusion, pressing, cooling, heat treatment recovery shaping, trimming, rolling and the like, and is wrapped on the surface of a heat insulation material, so that water vapor can be effectively prevented from permeating the heat insulation material, the heat insulation effect is ensured, and the service life of the heat insulation material is prolonged; the sealing film also has higher heat-resistant and moisture-resistant performance and stronger self-use stability.)

1. A high temperature resistant steam seal film which characterized in that: the preparation raw materials of the sealing film comprise butyl acetate, polymethylpentene, polyimide, polyacrylate, a modified carbon nano tube, an inorganic high-temperature-resistant auxiliary agent, glycidyl methacrylate and dibenzoyl peroxide.

2. The high temperature resistant water vapor sealing film of claim 1, wherein: the preparation raw materials of the sealing film comprise, by weight, 20-25 parts of butyl acetate, 12-15 parts of polymethylpentene, 8-12 parts of polyimide, 6-10 parts of polyacrylate, 5-10 parts of modified carbon nanotubes, 5-8 parts of inorganic high temperature resistant auxiliary agent, 2-12 parts of glycidyl methacrylate and 1-10 parts of dibenzoyl peroxide.

3. The high temperature resistant water vapor sealing film of claim 1, wherein: the modified carbon nanotube is obtained by acidifying a carbon nanotube with 70 wt% concentrated nitric acid.

4. The high temperature resistant water vapor sealing film of claim 3, wherein: the temperature of the acidification treatment is 60-65 ℃, and the treatment time is 0.5-2 h.

5. The high temperature resistant water vapor sealing film of claim 1, wherein: the inorganic high-temperature resistant auxiliary agent is formed by mixing silicon dioxide and magnesium stearate, and the weight ratio of the silicon dioxide to the magnesium stearate is 2-5: 1.

6. A method of making the high temperature resistant water vapor barrier film of any one of claims 1-5, wherein: comprises the steps of

Step one, mixing and stirring butyl acetate, polymethylpentene, polyimide, polyacrylate, a modified carbon nano tube and an inorganic high-temperature-resistant auxiliary agent for 2-6 hours to obtain a mixed raw material;

step two, adding glycidyl methacrylate and dibenzoyl peroxide into the mixed raw materials, fully stirring, and carrying out alkaline grafting reaction for 1-5h at 50-70 ℃ to obtain a modified mixed raw material;

step three, extruding the modified mixed raw materials at the temperature of 250-320 ℃ to obtain a primary embryonic membrane, and then performing compression molding and cooling on the primary embryonic membrane;

and step four, after cooling, carrying out heat treatment recovery shaping through a hot air drying tunnel at the temperature of 20-65 ℃, and finally, cutting edges and rolling to obtain the high-temperature-resistant water vapor sealing film.

Technical Field

The invention relates to the technical field of water vapor sealing, in particular to a high-temperature-resistant water vapor sealing film and a preparation method thereof.

Background

In some areas of China, in the process of construction and excavation of tunnels, due to high heat, the temperature in the tunnels is high, construction workers are difficult to carry out construction operation in the tunnels, and waterproof and drainage materials laid in later periods are likely to age quickly due to high temperature. Therefore, the surface of the mountain in the tunnel needs to be covered by heat insulation materials so as to achieve the effect of isolating the heat of the mountain and reducing the temperature in the tunnel.

However, since water seepage often occurs in the tunnel surrounding rock and the primary support, and a large amount of water vapor is formed in the high-ground-temperature environment, the water vapor easily penetrates through the heat-insulating material, so that the heat-insulating effect is reduced, and the service life of the heat-insulating material is also affected. Therefore, it is necessary to develop a sealing material capable of blocking high temperature water vapor.

Disclosure of Invention

The invention aims to provide a high-temperature-resistant water vapor sealing film and a preparation method thereof, which can block high-temperature water vapor generated in a tunnel and prevent the high-temperature water vapor from passing through a heat insulation material.

The invention realizes the purpose through the following technical scheme:

the high-temperature-resistant water vapor sealing film is prepared from butyl acetate, polymethylpentene, polyimide, polyacrylate, a modified carbon nanotube, an inorganic high-temperature-resistant auxiliary agent, glycidyl methacrylate and dibenzoyl peroxide.

The further improvement is that the preparation raw materials of the sealing film comprise, by weight, 20-25 parts of butyl acetate, 12-15 parts of polymethylpentene, 8-12 parts of polyimide, 6-10 parts of polyacrylate, 5-10 parts of modified carbon nano tubes, 5-8 parts of inorganic high-temperature-resistant auxiliary agent, 2-12 parts of glycidyl methacrylate and 1-10 parts of dibenzoyl peroxide.

In a further improvement, the modified carbon nanotube is obtained by acidifying carbon nanotube with 70 wt% concentrated nitric acid.

The further improvement is that the temperature of the acidification treatment is 60-65 ℃, and the treatment time is 0.5-2 h.

The further improvement is that the inorganic high-temperature resistant auxiliary agent is formed by mixing silicon dioxide and magnesium stearate, and the weight ratio of the silicon dioxide to the magnesium stearate is 2-5: 1.

The invention also provides a preparation method of the high-temperature-resistant water vapor sealing film, which comprises the following steps

Step one, mixing and stirring butyl acetate, polymethylpentene, polyimide, polyacrylate, a modified carbon nano tube and an inorganic high-temperature-resistant auxiliary agent for 2-6 hours to obtain a mixed raw material;

step two, adding glycidyl methacrylate and dibenzoyl peroxide into the mixed raw materials, fully stirring, and carrying out alkaline grafting reaction for 1-5h at 50-70 ℃ to obtain a modified mixed raw material;

step three, extruding the modified mixed raw materials at the temperature of 250-320 ℃ to obtain a primary embryonic membrane, and then performing compression molding and cooling on the primary embryonic membrane;

and step four, after cooling, carrying out heat treatment recovery shaping through a hot air drying tunnel at the temperature of 20-65 ℃, and finally, cutting edges and rolling to obtain the high-temperature-resistant water vapor sealing film.

The principle of the invention is as follows: butyl acetate as an organic solvent for each component; polymethyl pentene, polyimide and polyacrylate are used as main raw materials of the sealing film; the added modified carbon nano tube can increase the strength of the sealing membrane, high modulus, high temperature resistance, small thermal expansion coefficient and strong heat distortion resistance, and the modified carbon nano tube subjected to acidification increases the affinity between the modified carbon nano tube and a solute and improves the dispersibility of the modified carbon nano tube in the solute; the added glycidyl methacrylate is used as a monomer of an alkaline grafting reaction, and dibenzoyl peroxide is used as an initiator, so that the alkaline grafting reaction is carried out, under the condition of ensuring the leveling effect of the film, the prepared sealing film has excellent performances of high temperature resistance, weather resistance, aging resistance and the like, the heat shrinkage rate is reduced (about 0.02 percent at 150 ℃), the surface wetting tension of the sealing film is improved (about 61mN/m can be reached before corona treatment), and the extremely low water vapor transmittance (the lowest water vapor transmittance can reach 2.19 multiplied by 10)^-6g/m²·day)。

The invention has the beneficial effects that: the sealing film with strong temperature resistance and extremely low water vapor transmittance is prepared by the processes of mixing, alkaline grafting reaction, extrusion, pressing, cooling, heat treatment recovery shaping, trimming, rolling and the like, and is wrapped on the surface of a heat insulation material to effectively prevent water vapor from transmitting through the heat insulation material, so that the heat insulation effect is ensured, and the service life of the heat insulation material is prolonged; the sealing film also has higher heat-resistant and moisture-resistant performance and stronger self-use stability.

Detailed Description

The present application is described in further detail below with reference to examples, and it should be noted that the following detailed description is provided for further explanation of the present application and should not be construed as limiting the scope of the present application, and that certain insubstantial modifications and adaptations of the present application may be made by those skilled in the art based on the above-mentioned disclosure.