Thermal insulation weather-resistant composite material, preparation method and application on car cover

Abstract

The present application relates to the technical field of laminated composite material, and particularly relates to a heat-insulating weather-resistant composite material, a preparation method and application on car clothes. The composite material in the present application comprises three-layer structure of outer film, intermediate film and inner film, wherein the inner film is PP non-woven fabric, which is soft and will not damage car paint due to friction, the intermediate film is EPE foam cotton sheet, which has low air thermal conductivity in the pore structure and good heat insulation effect, and the outer film is prepared by electrospinning using polyacrylonitrile as main raw material. The polyacrylonitrile has good weather resistance and sunlight resistance, and the polyacrylonitrile is modified by introducing waterproof components and ultraviolet resistance components, so that the ultraviolet resistance performance and waterproof performance can be improved. In the modified polyacrylonitrile spinning solution, heat insulation components and antioxidant components are added, so that the heat insulation performance and antioxidant performance of the outer film can be improved.

Description

Technical Field

[0001] This invention relates to the field of layered composite material technology, specifically to a heat-insulating and weather-resistant composite material, its preparation method, and its application in car covers. Background Technology

[0002] When cars are parked in the open, they are easily affected by dust, dirt, rain, snow, and ultraviolet rays, which can affect their use. Therefore, it is generally necessary to cover the car with a car cover to protect it. Car covers exposed to the open environment for extended periods are prone to aging and damage, resulting in a short lifespan. Therefore, the materials used to make car covers must have high weather resistance. In addition, to prevent excessively high temperatures inside the car under sunlight, the car cover material must also have good heat insulation properties.

[0003] Chinese patent CN117301677B discloses a heat-insulating and flame-retardant car cover made of polyurethane layered material. The car cover consists of a first polyurethane layer, a second polyurethane layer, and a fiber layer bonded together with an adhesive. The polyurethane layer contains a heat-insulating and flame-retardant agent, which is prepared by using montmorillonite and aluminum trichloride. However, the heat-insulating and flame-retardant agent is an inorganic composite particle, which has poor compatibility and dispersion uniformity in polyurethane, resulting in insufficient heat insulation performance. In addition, the weather resistance of the car cover also needs to be improved. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing a heat-insulating and weather-resistant composite material to solve the problem of poor heat insulation and weather resistance in existing car covers.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a heat-insulating and weather-resistant composite material includes the following steps:

[0007] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. After the reaction is complete, precipitate, filter, wash and dry to obtain modified polyacrylonitrile.

[0008] Step 2: Add modified polyacrylonitrile to N,N-dimethylformamide and stir until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine and continue the reaction. After the reaction is completed, the reaction solution is obtained. The reaction solution is electrospun, dried, and rolled to obtain modified polyacrylonitrile fiber membrane.

[0009] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer membrane, EPE (Expandable Polyethylene) foam cotton sheet as the middle membrane, and PP nonwoven fabric as the inner membrane, the outer membrane, middle membrane and inner membrane are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0010] Preferably, in step one, the mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-acryloxy-2-hydroxybenzophenone, and benzoyl peroxide is 100:(800-1000):(2.5-5):(3.5-6):(0.05-0.1).

[0011] Preferably, in step one, the stirring conditions are a stirring speed of 100-200 r / min and a temperature of 50-70°C, and the reaction conditions are a reaction at 80-90°C for 1.5-2.5 h.

[0012] Preferably, in step two, the mass ratio of modified polyacrylonitrile, N,N-dimethylformamide, epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine is 100:(800-1000):(0.5-1):(1-2):(4-5).

[0013] Preferably, in step two, the stirring conditions are: stirring at a speed of 100-200 r / min and a temperature of 50-70°C; and the reaction continues at a speed of 100-200 r / min and a temperature of 75-85°C for 30-40 hours.

[0014] Preferably, in step two, during electrospinning, the spinning voltage is 28kV, the flow rate is 0.5mL / h, and the receiving distance is 15cm.

[0015] Preferably, the epoxy-modified montmorillonite in step two is prepared by the following steps:

[0016] The pH of the ethanol-water solution was adjusted to 3.5-4.5, γ-glycidoxypropyltrimethoxysilane was added, and after hydrolysis, montmorillonite was added. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy-modified montmorillonite.

[0017] Preferably, the mass ratio of the ethanol aqueous solution, γ-glycidyl etheroxypropyltrimethoxysilane, and montmorillonite is 100:2.5:(2.5-4), the hydrolysis conditions are hydrolysis at a stirring speed of 100-200 r / min for 3.5-4.5 h, and the reaction conditions are reflux reaction at 65-75 °C for 20-30 h.

[0018] Preferably, the ethanol aqueous solution is a 90 wt% ethanol aqueous solution.

[0019] Preferably, the epoxy-modified silver powder in step two is prepared by the following steps:

[0020] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, the pH was adjusted to 4-6, silver powder was added, and the reaction was carried out. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy-modified silver powder.

[0021] Preferably, the mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1, and the mass ratio of the mixed solvent, γ-glycidyl etheroxypropyltrimethoxysilane, and silver powder is 100:1:(1-2). The reaction conditions are 8-10 h at a temperature of 50-70°C.

[0022] The present invention also discloses a heat-insulating and weather-resistant composite material prepared by the above-described method for preparing heat-insulating and weather-resistant composite materials.

[0023] Preferably, the application of a heat-insulating and weather-resistant composite material as described above in a car cover.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The composite material in this invention comprises a three-layer structure: an outer membrane, a middle membrane, and an inner membrane. The inner membrane is made of PP nonwoven fabric, a soft material that will not damage the paint due to friction. The middle membrane is made of EPE foam, whose porous structure has a low air thermal conductivity and good heat insulation. The outer membrane is made from polyacrylonitrile as the main raw material through electrospinning. Polyacrylonitrile has good weather resistance and sun resistance. After modification, waterproof and UV-resistant components are introduced, improving its UV resistance and waterproof performance. The modified polyacrylonitrile spinning solution contains heat-insulating and antioxidant components, further enhancing the heat insulation and antioxidant properties of the outer membrane. With the aid of antioxidants and UV-resistant components, the outer membrane exhibits good anti-aging properties and high weather resistance.

[0026] During the modification process of polyacrylonitrile, under the action of the initiator, the waterproof component hexafluorobutyl acrylate and the UV-resistant component 4-propenoxy-2-hydroxybenzophenone are grafted onto the polyacrylonitrile molecular chain. The waterproof component and the UV-resistant component have high compatibility and uniform dispersion in polyacrylonitrile, and good UV resistance and waterproof performance.

[0027] The antioxidant is N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, which has strong antioxidant properties and good stability. Its molecular chain can intertwine with the polyacrylonitrile molecular chain. The heat insulation components are montmorillonite and silver powder. Montmorillonite has a layered heat insulation effect, and silver powder has a high reflectivity, which can reflect heat away. Both have good heat insulation performance. Montmorillonite and silver powder are epoxy modified, and the epoxy groups interact with N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine. The ring-opening reaction of the imino group on the (hydroxyphenyl)propionyl)hexamethylenediamine molecule links montmorillonite and silver powder to the N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine molecule through stable chemical bonds. This, in turn, improves the compatibility and dispersion uniformity of montmorillonite and silver powder in the modified polyacrylonitrile spinning solution through the entanglement between the N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine and polyacrylonitrile molecular chains, thereby enhancing the thermal insulation performance.

[0028] Figure 1 This is a flowchart illustrating the preparation process of the thermal insulation and weather-resistant composite material in this invention.

[0029] Figure 2 The bar chart shows the test results of the thermal insulation performance of the modified polyacrylonitrile fiber membranes prepared in Examples 1-6 and Comparative Examples 1-2 of the present invention.

[0030] Figure 3 The bar chart shows the UV aging resistance test results of the modified polyacrylonitrile fiber membranes prepared in Examples 1-6 and Comparative Examples 1-2 of the present invention. Detailed Implementation

[0031] Example 1

[0032] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0033] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 100 r / min and 70℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:800:2.5:3.5:0.05. React at 80℃ for 2.5 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0034] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 100 r / min and 70℃ until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The mass ratio of hydroxyphenyl propionyl hexamethylenediamine was 100:800:0.5:1:4. The reaction was carried out at 75℃ for 40 h with a stirring speed of 100 r / min. After the reaction was completed, the reaction solution was obtained. The reaction solution was electrospun at a voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The solution was dried in a vacuum drying oven at 60℃ for 12 h and then rolled at a pressure of 5 MPa for 2 min to obtain a modified polyacrylonitrile fiber membrane.

[0035] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0036] The epoxy-modified montmorillonite is prepared by the following steps:

[0037] The pH of a 90 wt% ethanol aqueous solution was adjusted to 3.5 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and hydrolysis was carried out at a stirring speed of 100 r / min for 4.5 h. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:2.5. The mixture was refluxed at 65 °C for 30 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0038] Epoxy-modified silver powder is prepared by the following steps:

[0039] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 4 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of the mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:1. The mixture was reacted at 50℃ for 10h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20h to obtain epoxy modified silver powder.

[0040] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0041] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0042] Example 2

[0043] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0044] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 200 r / min and 50℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:1000:5:6:0.1. React at 90℃ for 1.5 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0045] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 200 r / min and 50℃ until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The mass ratio of hydroxyphenylpropionyl hexamethylenediamine was 100:1000:1:2:5. The reaction was carried out at 85℃ for 30 h with a stirring speed of 200 r / min. After the reaction was completed, the reaction solution was obtained. The reaction solution was electrospun at a voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The solution was dried in a vacuum drying oven at 60℃ for 12 h and then rolled at a pressure of 5 MPa for 2 min to obtain a modified polyacrylonitrile fiber membrane.

[0046] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0047] The epoxy-modified montmorillonite is prepared by the following steps:

[0048] The pH of a 90 wt% ethanol aqueous solution was adjusted to 4.5 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and hydrolysis was carried out for 3.5 h with stirring at 200 r / min. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:4. The mixture was refluxed at 75 °C for 20 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0049] Epoxy-modified silver powder is prepared by the following steps:

[0050] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 6 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of the mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:2. The mixture was reacted at 70℃ for 8 hours. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20 hours to obtain epoxy-modified silver powder.

[0051] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0052] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0053] Example 3

[0054] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0055] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:840:3:4:0.06. React at 85℃ for 2 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0056] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The mass ratio of phenylpropionyl hexamethylenediamine was 100:840:0.6:1.2:4.2. The reaction was carried out at 80℃ for 36 hours with a stirring speed of 150 r / min. After the reaction was completed, the reaction solution was obtained. The reaction solution was electrospun at a voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The solution was dried in a vacuum drying oven at 60℃ for 12 hours and then rolled at a pressure of 5 MPa for 2 minutes to obtain a modified polyacrylonitrile fiber membrane.

[0057] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0058] The epoxy-modified montmorillonite is prepared by the following steps:

[0059] The pH of a 90 wt% ethanol aqueous solution was adjusted to 4 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and the mixture was hydrolyzed for 4 h with stirring at 150 r / min. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:2.8. The mixture was refluxed at 70 °C for 24 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0060] Epoxy-modified silver powder is prepared by the following steps:

[0061] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 5 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:1.2. The mixture was reacted at 60℃ for 9 hours. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20 hours to obtain epoxy modified silver powder.

[0062] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0063] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0064] Example 4

[0065] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0066] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:880:3.5:4.5:0.07. React at 85℃ for 2 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0067] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The mass ratio of phenylpropionyl hexamethylenediamine was 100:880:0.7:1.4:4.4. The reaction was carried out at 80℃ for 36 hours with a stirring speed of 150 r / min. After the reaction was completed, the reaction solution was obtained. The reaction solution was electrospun at a voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The solution was dried in a vacuum drying oven at 60℃ for 12 hours and then rolled at a pressure of 5 MPa for 2 minutes to obtain a modified polyacrylonitrile fiber membrane.

[0068] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0069] The epoxy-modified montmorillonite is prepared by the following steps:

[0070] The pH of a 90 wt% ethanol aqueous solution was adjusted to 4 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and hydrolysis was carried out for 4 h with stirring at 150 r / min. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:3.1. The mixture was refluxed at 70 °C for 24 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0071] Epoxy-modified silver powder is prepared by the following steps:

[0072] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 5 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of the mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:1.4. The mixture was reacted at 60℃ for 9 hours. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20 hours to obtain epoxy-modified silver powder.

[0073] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0074] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0075] Example 5

[0076] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0077] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:920:4:5:0.08. React at 85℃ for 2 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0078] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The mass ratio of phenylpropionyl hexamethylenediamine was 100:920:0.8:1.6:4.6. The reaction was carried out at 80℃ for 36 hours with a stirring speed of 150 r / min. After the reaction was completed, the reaction solution was obtained. The reaction solution was electrospun at a voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The solution was dried in a vacuum drying oven at 60℃ for 12 hours and then rolled at a pressure of 5 MPa for 2 minutes to obtain a modified polyacrylonitrile fiber membrane.

[0079] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0080] The epoxy-modified montmorillonite is prepared by the following steps:

[0081] The pH of a 90 wt% ethanol aqueous solution was adjusted to 4 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and hydrolysis was carried out for 4 h with stirring at 150 r / min. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:3.4. The mixture was refluxed at 70 °C for 24 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0082] Epoxy-modified silver powder is prepared by the following steps:

[0083] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 5 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of the mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:1.6. The mixture was reacted at 60℃ for 9 hours. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20 hours to obtain epoxy-modified silver powder.

[0084] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0085] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0086] Example 6

[0087] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0088] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:960:4.5:5.5:0.09. React at 85℃ for 2 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0089] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 150 r / min and 60℃ until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The mass ratio of phenylpropionyl hexamethylenediamine was 100:960:0.9:1.8:4.8. The reaction was carried out at a stirring speed of 150 r / min and a temperature of 80 °C for 36 h. After the reaction was completed, the reaction solution was obtained. The reaction solution was electrospun at a spinning voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The solution was dried in a vacuum drying oven at 60 °C for 12 h and then rolled at a pressure of 5 MPa for 2 min to obtain a modified polyacrylonitrile fiber membrane.

[0090] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0091] The epoxy-modified montmorillonite is prepared by the following steps:

[0092] The pH of a 90 wt% ethanol aqueous solution was adjusted to 4 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and hydrolysis was carried out for 4 h with stirring at 150 r / min. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:3.7. The mixture was refluxed at 70 °C for 24 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0093] Epoxy-modified silver powder is prepared by the following steps:

[0094] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 5 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of the mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:1.8. The mixture was reacted at 60℃ for 9 hours. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20 hours to obtain epoxy-modified silver powder.

[0095] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0096] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0097] Comparative Example 1

[0098] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0099] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 100 r / min and 70℃ until dissolved. Add hexafluorobutyl acrylate and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, and benzoyl peroxide is 100:800:2.5:0.05. React at 80℃ for 2.5 h. After the reaction is complete, add 3 times the mass of ethanol to precipitate N,N-dimethylformamide. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0100] Step 2: Add modified polyacrylonitrile to N,N-dimethylformamide and stir at 100 r / min and 70℃ until dissolved. Add epoxy-modified montmorillonite, epoxy-modified silver powder and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine and react at 100 r / min and 75℃ for 40 h. After the reaction is complete, the reaction solution is obtained. Add 4-propenoxy-2-hydroxybenzophenone to the reaction solution and stir to obtain a mixture. Electrospin the mixture at a voltage of 28 kV, a flow rate of 0.5 mL / h and a receiving distance of 15 cm. Dry in a vacuum drying oven at 60℃ for 12 h and roll under a pressure of 5 MPa for 2 min to obtain a modified polyacrylonitrile fiber membrane.

[0101] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0102] The mass ratio of modified polyacrylonitrile, N,N-dimethylformamide, epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine and 4-propenoxy-2-hydroxybenzophenone is 100:800:0.5:1:4:3.3.

[0103] Epoxy-modified montmorillonite is prepared by the following steps:

[0104] The pH of a 90 wt% ethanol aqueous solution was adjusted to 3.5 using a 1 wt% acetic acid aqueous solution. γ-glycidoxypropyltrimethoxysilane was added, and hydrolysis was carried out at a stirring speed of 100 r / min for 4.5 h. Montmorillonite was then added, and the mass ratio of 90 wt% ethanol aqueous solution, γ-glycidoxypropyltrimethoxysilane, and montmorillonite was 100:2.5:2.5. The mixture was refluxed at 65 °C for 30 h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50 °C for 20 h to obtain epoxy-modified montmorillonite.

[0105] Epoxy-modified silver powder is prepared by the following steps:

[0106] The mixed solvent was mixed with γ-glycidoxypropyltrimethoxysilane, and the pH was adjusted to 4 with 1wt% acetic acid aqueous solution. Silver powder was added. The mass ratio of the mixed solvent, γ-glycidoxypropyltrimethoxysilane and silver powder was 100:1:1. The mixture was reacted at 50℃ for 10h. After the reaction was completed, the mixture was filtered, washed three times with ethanol, and dried in a vacuum drying oven at 50℃ for 20h to obtain epoxy modified silver powder.

[0107] The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1;

[0108] Step 2: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0109] Comparative Example 2

[0110] This embodiment discloses a method for preparing a heat-insulating and weather-resistant composite material, including the following steps:

[0111] Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir at 100 r / min and 70℃ until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. The mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide is 100:800:2.5:3.5:0.05. React at 80℃ for 2.5 h. After the reaction is complete, add 3 times the mass of N,N-dimethylformamide in ethanol for precipitation. Filter, wash 3 times with ethanol, and dry in a vacuum drying oven at 50℃ for 20 h to obtain modified polyacrylonitrile.

[0112] Step 2: Add the modified polyacrylonitrile to N,N-dimethylformamide and stir at 100 r / min and 70°C until dissolved. Add montmorillonite, silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine. The amines were mixed at a mass ratio of 100:800:0.45:0.9:4 at 75°C for 40 hours at a stirring speed of 100 r / min. After the reaction was completed, a mixture was obtained. The mixture was electrospun at a voltage of 28 kV, a flow rate of 0.5 mL / h, and a receiving distance of 15 cm. The mixture was then dried in a vacuum drying oven at 60°C for 12 hours and rolled at a pressure of 5 MPa for 2 minutes to obtain a modified polyacrylonitrile fiber membrane.

[0113] The thickness of the modified polyacrylonitrile fiber membrane is 50 μm;

[0114] Step 3: Using a modified polyacrylonitrile fiber membrane as the outer layer, an EPE foam sheet as the middle layer, and a PP nonwoven fabric as the inner layer, the outer, middle, and inner layers are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

[0115] In the above examples and comparative examples, the polyacrylonitrile resin was purchased from Hubei Shuaiyan Ligao Biomedical Co., Ltd., item number: SYLG-1106, molecular weight: 90,000; montmorillonite was purchased from Guangzhou Yifeng Chemical Technology Co., Ltd., model: TY-710C, particle size: 50nm; silver powder was purchased from Shanghai Yaotian New Material Technology Co., Ltd., item number: YT-Ag-04-1, average particle size: 50nm; EPE foam cotton sheet was purchased from Hongbaotai Packaging Industry Co., Ltd., thickness: 0.5mm; PP nonwoven fabric was purchased from Hunan Mingyu Nonwoven Fabric Co., Ltd., item number: MYWFB11, basis weight: 50g / m³. 2 The pressure-sensitive adhesive was purchased from Ingenic Technology (Guangdong) Co., Ltd., type: acrylic adhesive, item number: IRW-E027L, solid content: 60%, viscosity: 1200mPa·s.

[0116] Test case

[0117] The performance of the modified polyacrylonitrile fiber membranes prepared in Examples 1-6 and Comparative Examples 1-2 was tested:

[0118] (1) Thermal insulation performance: The out-of-plane thermal conductivity of the modified polyacrylonitrile fiber membrane was measured with reference to the standard ASTM D5470. The results are shown in Table 1.

[0119] Table 1

[0120]

[0121] As shown in Table 1, the modified polyacrylonitrile fiber membrane prepared by this invention has good thermal insulation performance. Montmorillonite has a sheet-like thermal insulation effect, and silver powder has a high reflectivity, which can reflect heat away. Both have good thermal insulation performance. Montmorillonite and silver powder are connected to the N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine molecule through stable chemical bonds. The compatibility and dispersion uniformity of montmorillonite and silver powder in the modified polyacrylonitrile spinning solution are improved by the mutual entanglement between N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine and polyacrylonitrile molecular chains, thereby enhancing the thermal insulation performance. Compared with Example 1, in Comparative Example 2, montmorillonite and silver powder did not form chemical bonds with N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, resulting in reduced compatibility and dispersion uniformity in the modified polyacrylonitrile spinning solution, weakened thermal insulation performance, and increased thermal conductivity.

[0122] (2) UV aging resistance: The modified polyacrylonitrile fiber membrane strip samples were irradiated at 25℃ under a 300W high-pressure mercury lamp for 240h with a lamp distance of 5cm. The tensile properties were then tested after irradiation. The results are shown in Table 2.

[0123] Table 2

[0124]

[0125] As shown in Table 2, the modified polyacrylonitrile fiber membrane prepared in this invention exhibits excellent UV aging resistance. During the preparation of the modified polyacrylonitrile fiber membrane, the UV-resistant component 4-propenoxy-2-hydroxybenzophenone is introduced into the polyacrylonitrile. Since 4-propenoxy-2-hydroxybenzophenone is linked to the polyacrylonitrile by stable chemical bonds, the UV-resistant component exhibits high compatibility and uniform dispersion in the polyacrylonitrile, resulting in good UV aging resistance. Compared to Example 1, in Comparative Example 1, 4-propenoxy-2-hydroxybenzophenone was not linked to the polyacrylonitrile molecular chain by stable chemical bonds, leading to a decrease in UV aging resistance.

[0126] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a heat-insulating and weather-resistant composite material, characterized in that, Includes the following steps: Step 1: Add polyacrylonitrile resin to N,N-dimethylformamide and stir until dissolved. Add hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone and benzoyl peroxide. After the reaction is complete, precipitate, filter, wash and dry to obtain modified polyacrylonitrile. Step 2: Add modified polyacrylonitrile to N,N-dimethylformamide and stir until dissolved. Then add epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine and continue the reaction. After the reaction is completed, the reaction solution is obtained. The reaction solution is electrospun, dried, and rolled to obtain modified polyacrylonitrile fiber membrane. Step 3: Using modified polyacrylonitrile fiber membrane as the outer membrane, EPE foam cotton sheet as the middle membrane, and PP nonwoven fabric as the inner membrane, the outer membrane, middle membrane and inner membrane are bonded together with pressure-sensitive adhesive to obtain a heat-insulating and weather-resistant composite material.

2. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, In step one, the mass ratio of polyacrylonitrile resin, N,N-dimethylformamide, hexafluorobutyl acrylate, 4-propenoxy-2-hydroxybenzophenone, and benzoyl peroxide is 100:(800-1000):(2.5-5):(3.5-6):(0.05-0.1).

3. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, In step one, the stirring conditions are a stirring speed of 100-200 r / min and a temperature of 50-70℃, and the reaction conditions are a reaction at 80-90℃ for 1.5-2.5 h.

4. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, In step two, the mass ratio of modified polyacrylonitrile, N,N-dimethylformamide, epoxy-modified montmorillonite, epoxy-modified silver powder, and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine is 100:(800-1000):(0.5-1):(1-2):(4-5).

5. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, In step two, the stirring conditions are: stirring at a speed of 100-200 r / min and a temperature of 50-70°C; and the reaction is continued at a speed of 100-200 r / min and a temperature of 75-85°C for 30-40 hours.

6. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, In step two, during electrospinning, the spinning voltage is 28kV, the flow rate is 0.5mL / h, and the receiving distance is 15cm.

7. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, The epoxy-modified montmorillonite in step two is prepared through the following steps: The pH of the ethanol aqueous solution was adjusted to 3.5-4.5, γ-glycidoxypropyltrimethoxysilane was added, and after hydrolysis, montmorillonite was added. After the reaction was completed, the mixture was filtered, washed, and dried to obtain epoxy-modified montmorillonite. The mass ratio of the ethanol aqueous solution, γ-glycidyl etheroxypropyltrimethoxysilane, and montmorillonite is 100:2.5:(2.5-4). The hydrolysis conditions are: hydrolysis at a stirring speed of 100-200 r / min for 3.5-4.5 h, and reflux reaction at 65-75℃ for 20-30 h.

8. The method for preparing a heat-insulating and weather-resistant composite material according to claim 1, characterized in that, The epoxy-modified silver powder in step two is prepared by the following steps: Mix the mixed solvent with γ-glycidoxypropyltrimethoxysilane, adjust the pH to 4-6, add silver powder, react, filter, wash, and dry to obtain epoxy-modified silver powder. The mixed solvent is composed of ethyl acetate / butyl acetate / cyclohexanone in a mass ratio of 2:1:1, and the mass ratio of the mixed solvent, γ-glycidyl etheroxypropyltrimethoxysilane, and silver powder is 100:1:(1-2). The reaction conditions are 8-10 h at a temperature of 50-70°C.

9. A heat-insulating and weather-resistant composite material prepared by the preparation method of the heat-insulating and weather-resistant composite material as described in any one of claims 1-8.

10. The application of the heat-insulating and weather-resistant composite material as described in claim 9 in a car cover.

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