Light-weight composite heat preservation quilt for greenhouse and preparation method of light-weight composite heat preservation quilt

Abstract

The invention relates to the technical field of heat preservation, and particularly discloses a light-weight composite heat preservation quilt for a greenhouse and a preparation method of the light-weight composite heat preservation quilt. The light-weight greenhouse composite heat preservation quilt comprises two waterproof layers and a heat preservation layer, the heat preservation layer is located between the two waterproof layers, and the heat preservation layer is prepared from, by weight, 60-85 parts of polyurethane, 5-8 parts of modified silicon dioxide aerogel, 0.5-1.2 parts of composite flame retardant and 15-25 parts of foam stabilizer; in addition, the preparation method has the advantages that the heat preservation effect of the heat preservation quilt is guaranteed, meanwhile, the mass of the heat preservation quilt is reduced, and durability is improved.

Description

Technical Field

[0001] The present application relates to the technical field of thermal insulation, and more specifically, it relates to a lightweight greenhouse composite thermal insulation quilt and a preparation method thereof. Background Art

[0002] A greenhouse is an important planting tool that can accurately control the temperature, humidity, light, etc. of the crops in the greenhouse under relatively harsh environments, enabling the cultivation of crops in unsuitable environments and improving the yield and quality of the crops.

[0003] The greenhouse uses a composite thermal insulation quilt to insulate the inside of the greenhouse and reduce the loss of internal heat, so that the inside of the greenhouse can be maintained at a relatively suitable temperature, enabling the crops to grow, mature, and be harvested normally. However, in order to ensure the thermal insulation effect of the existing greenhouse thermal insulation quilt, materials with a relatively large thickness and density are often used, which are relatively heavy in overall weight, have poor waterproof performance, poor durability, and are not convenient for transportation and installation. Summary of the Invention

[0004] In order to ensure the thermal insulation effect of the thermal insulation quilt while reducing the quality of the thermal insulation quilt and improving its durability, the present application provides a lightweight greenhouse composite thermal insulation quilt and a preparation method thereof.

[0005] In a first aspect, the present application provides a lightweight greenhouse composite thermal insulation quilt, adopting the following technical solution: A lightweight greenhouse composite thermal insulation quilt includes two layers of waterproof layers and one layer of thermal insulation layer. The thermal insulation layer is located between the two waterproof layers. The thermal insulation layer includes the following raw materials in parts by weight: 60 - 85 parts of polyurethane, 5 - 8 parts of modified silica aerogel, 0.5 - 1.2 parts of composite flame retardant, and 15 - 25 parts of foam stabilizer.

[0006] By adopting the above technical solution, after the polyurethane is foamed, it has a porous structure inside, reducing its density and achieving lightweight. At the same time, the thermal conductivity coefficient of polyurethane is relatively low, which can effectively reduce heat dissipation. The addition of modified silica aerogel increases the complexity of its internal structure and reduces the heat exchange efficiency on both sides of the composite thermal insulation quilt, thereby improving the thermal insulation effect of the thermal insulation quilt. The addition of the composite flame retardant can effectively increase the flame retardant performance of the composite thermal insulation quilt, and the addition of the waterproof layer can improve the waterproof performance of the composite thermal insulation quilt, thereby improving the durability of the composite thermal insulation quilt.

[0007] Preferably, the modified silica aerogel is polyethylene glycol / silica aerogel.

[0008] By adopting the above technical solution, in the polyethylene glycol / silica aerogel, the chambers formed by partitioning the internal structure of the silica aerogel can accommodate polyethylene glycol. When the surrounding environment of the composite thermal insulation blanket changes, the polyethylene glycol can undergo a phase change to absorb and release heat, thereby maintaining the temperature stability and effectively improving the thermal insulation performance of the thermal insulation blanket.

[0009] Preferably, the preparation method of the polyethylene glycol / silica aerogel: Mix tetraethyl orthosilicate, water and ethanol, stir at 55 - 60 °C for 1 h, adjust the pH to 2 - 3 with 37 wt% hydrochloric acid, maintain the temperature at 55 - 60 °C and stir for 1.5 - 2 h, add 10 wt% ammonia water to adjust the pH to 6 - 7 to obtain a sol, add polyethylene glycol to the sol, continue stirring to obtain a wet gel, dry the wet gel at 80 - 85 °C for 11 - 12 h, and pulverize to obtain the polyethylene glycol / silica aerogel.

[0010] By adopting the above technical solution, tetraethyl orthosilicate hydrolyzes to form a silica gel. Adding polyethylene glycol to the sol enables the sol to fully absorb water and polyethylene glycol to form a composite material. The silica aerogel can play a role in restricting the phase - changing polyethylene glycol, so that the polyethylene glycol is not easily lost and maintains its phase - change heat storage performance.

[0011] Preferably, before adding polyethylene glycol to the sol, the following treatment is also carried out: Add polyester fiber to the sol and disperse it evenly by ultrasonic treatment.

[0012] By adopting the above technical solution, the polyester fiber has good mechanical properties. Adding the polyester fiber to the sol can effectively improve the strength of the modified silica aerogel, so that the thickness of the composite thermal insulation blanket decreases without affecting its strength.

[0013] Preferably, before adding polyethylene glycol to the sol, hexamethyldisilazane is also added, and the addition amount of hexamethyldisilazane is 30 - 34 wt% of tetraethyl orthosilicate.

[0014] By adopting the above technical solution, the addition of hexamethyldisilazane can promote the formation of a more complete network structure of the silica aerogel skeleton, improve its capacity, further improve the heat storage performance of the polyethylene glycol / silica aerogel, and be able to respond to a larger range of temperature changes.

[0015] Preferably, the composite flame retardant includes magnesium hydroxide and carbon microspheres.

[0016] By adopting the above technical solution, magnesium hydroxide can improve the flame - retardant performance of the composite thermal insulation blanket and at the same time inhibit the generation of smoke and toxic gases. The carbon microspheres have high thermal stability and can improve the thermal stability and flame - retardant performance of the composite thermal insulation blanket. The combination of the two plays a synergistic effect and can further improve the flame - retardant effect of the composite thermal insulation blanket.

[0017] Preferably, the preparation method of the composite flame retardant is as follows: carbon microspheres are dispersed in an aqueous alcohol solution of magnesium chloride, and a dispersant is added. After ultrasonic oscillation for 25 - 30 min, a mixed solution is obtained. An aqueous alcohol solution of sodium hydroxide is added dropwise to the mixed solution, and the reaction is carried out at 60 - 65 °C for 18 h. It is washed with absolute ethanol and water until neutral, and dried at 110 - 115 °C for 4.5 - 5 h to obtain the composite flame retardant.

[0018] By adopting the above technical solution, magnesium chloride reacts with sodium hydroxide to generate magnesium hydroxide, and magnesium hydroxide deposits on the surface of carbon microspheres to form a composite flame retardant, enabling the synergistic effect of magnesium hydroxide and carbon microspheres, and improving the flame retardant performance of the composite thermal insulation quilt.

[0019] In the second aspect, the present application provides a preparation method of a lightweight greenhouse composite thermal insulation quilt, adopting the following technical solution: A preparation method of a lightweight greenhouse composite thermal insulation quilt includes the following steps: After mixing polyurethane, modified silica aerogel, and the composite flame retardant, a foam stabilizer is added and foaming is carried out to form a plate-shaped thermal insulation layer with a thickness of 4 - 7 mm. The waterproof layer is sewn and assembled with the obtained thermal insulation layer to obtain the lightweight greenhouse composite thermal insulation quilt.

[0020] By adopting the above technical solution, the obtained composite thermal insulation quilt has a smaller density, better heat preservation effect, lighter total weight, and good waterproof performance.

[0021] In summary, the present application has the following beneficial effects: 1. In the present application, after the polyurethane is foamed, it has a porous structure inside, reducing its density and achieving lightweight. At the same time, the thermal conductivity coefficient of polyurethane is low, which can effectively reduce heat dissipation. The addition of modified silica aerogel increases the complexity of its internal structure and reduces the heat exchange efficiency on both sides of the composite thermal insulation quilt, thereby improving the heat preservation effect of the thermal insulation quilt. The addition of the composite flame retardant can effectively increase the flame retardant performance of the composite thermal insulation quilt.

[0022] 2. In the present application, in polyethylene glycol / silica aerogel, the chambers formed by the internal structure separation of silica aerogel can accommodate polyethylene glycol. When the surrounding environment of the composite thermal insulation quilt changes, polyethylene glycol can undergo a phase change to absorb and release heat, thereby maintaining temperature stability and effectively improving the heat preservation performance of the thermal insulation quilt.

[0023] 3. In the present application, tetraethyl orthosilicate hydrolyzes to form silica gel, and polyethylene glycol is added to the sol, enabling the sol to fully absorb polyethylene glycol and form a composite material. Silica aerogel can play a restrictive role on the phase-changing polyethylene glycol, making polyethylene glycol not easily lost and maintaining its phase change heat storage performance. Detailed implementation manners

[0024] The following further elaborates on this application in conjunction with embodiments.

[0025] Preparation Examples 1 - 6 of modified silica aerogel Preparation Example 1 The modified silica aerogel is polyethylene glycol / silica aerogel. The preparation method of polyethylene glycol / silica aerogel: Mix 1 g of tetraethyl orthosilicate, 5 g of water, and 8 g of ethanol, stir at 55 °C for 1 h, adjust the pH to 2 using 37 wt% hydrochloric acid, maintain the temperature at 55 °C and stir for 2 h, add 10 wt% ammonia water to adjust the pH to 6 to obtain a sol. Add polyethylene glycol to the sol, and the addition amount of polyethylene glycol is 50 wt% of the total weight. Continue stirring to obtain a wet gel, dry the wet gel at 80 °C for 12 h, and pulverize to obtain polyethylene glycol / silica aerogel, which is the modified silica aerogel.

[0026] Preparation Example 2 The modified silica aerogel is polyethylene glycol / silica aerogel. The preparation method of polyethylene glycol / silica aerogel: Mix 1.1 g of tetraethyl orthosilicate, 5.2 g of water, and 8.5 g of ethanol, stir at 60 °C for 1 h, adjust the pH to 3 using 37 wt% hydrochloric acid, maintain the temperature at 60 °C and stir for 1.5 h, add 10 wt% ammonia water to adjust the pH to 7 to obtain a sol. Add polyethylene glycol to the sol, and the addition amount of polyethylene glycol is 60 wt% of the total weight. Continue stirring to obtain a wet gel, dry the wet gel at 85 °C for 11 h, and pulverize to obtain polyethylene glycol / silica aerogel, which is the modified silica aerogel.

[0027] Preparation Example 3 The difference between Preparation Example 3 and Preparation Example 1 is that in Preparation Example 3, before adding polyethylene glycol to the sol, the following treatment is also carried out: Add polyester fiber to the sol and ultrasonically disperse it evenly. The addition amount of polyester fiber is 1.42 wt% of the total weight of polyethylene glycol / silica aerogel.

[0028] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that in Preparation Example 4, before adding polyethylene glycol to the sol, the following treatment is also carried out: Add polyester fiber to the sol and ultrasonically disperse it evenly. The addition amount of polyester fiber is 1.58 wt% of the total weight of polyethylene glycol / silica aerogel.

[0029] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 1 is that in Preparation Example 5, before adding polyethylene glycol to the sol, hexamethyldisilazane is also added. The addition amount of hexamethyldisilazane is 30 wt% of tetraethyl orthosilicate.

[0030] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 1 is that in Preparation Example 6, before adding polyethylene glycol to the sol, hexamethyldisilazane is also added, and the addition amount of hexamethyldisilazane is 34 wt% of tetraethyl orthosilicate.

[0031] Preparation Examples 7 - 10 of Composite Flame Retardant Preparation Example 7 Preparation method of composite flame retardant: Disperse 4 g of carbon microspheres in 100 mL of an aqueous alcohol solution of magnesium chloride with a concentration of 0.1 g / L. The volume ratio of ethanol to water in the aqueous alcohol solution of magnesium chloride is 1:1, and 1 mL of dispersant OP - 10 is added. After ultrasonic oscillation for 30 min, a mixed solution is obtained. Then, an aqueous alcohol solution of 10 wt% sodium hydroxide is added dropwise to the mixed solution. The volume ratio of ethanol to water in the aqueous alcohol solution of sodium hydroxide is 1:1. React at 60 °C for 18 h, wash with absolute ethanol and water until neutral, and dry at 115 °C for 4.5 h to obtain the composite flame retardant.

[0032] Preparation Example 8 Preparation method of composite flame retardant: Disperse 5 g of carbon microspheres in 100 mL of an aqueous alcohol solution of magnesium chloride with a concentration of 0.12 g / L. The volume ratio of ethanol to water in the aqueous alcohol solution of magnesium chloride is 1:1, and 1.2 mL of dispersant OP - 10 is added. After ultrasonic oscillation for 25 min, a mixed solution is obtained. Then, an aqueous alcohol solution of 10 wt% sodium hydroxide is added dropwise to the mixed solution. The volume ratio of ethanol to water in the aqueous alcohol solution of sodium hydroxide is 1:1. React at 65 °C for 18 h, wash with absolute ethanol and water until neutral, and dry at 110 °C for 5 h to obtain the composite flame retardant.

[0033] Preparation Example 9 The difference between Preparation Example 9 and Preparation Example 7 is that the concentration of magnesium chloride is 0.01 g / L.

[0034] Preparation Example 10 The difference between Preparation Example 10 and Preparation Example 7 is that the concentration of magnesium chloride is 0.5 g / L. Examples

[0035] Example 1 A lightweight greenhouse composite heat - insulating quilt includes two waterproof layers and one heat - insulating layer. The heat - insulating layer is located between the two waterproof layers. The waterproof layer is made of PVC waterproof cloth with a thickness of 1.6 mm. The heat - insulating layer includes the following raw materials in parts by weight: 60 kg of polyurethane, 5 kg of modified silica aerogel, 0.5 kg of composite flame retardant, and 15 kg of foam stabilizer. The foam stabilizer is EPP - 112 produced by Evonik Industries (Shanghai) Co., Ltd. The modified silica aerogel is the modified silica aerogel prepared in Preparation Example 1, and the composite flame retardant is the composite flame retardant prepared in Preparation Example 7.

[0036] The preparation method of the above lightweight greenhouse composite heat-insulating quilt is as follows: after mixing polyurethane, modified silica aerogel, and composite flame retardant, a foam stabilizer is added and foaming is carried out to form a plate-shaped heat-insulating layer with a thickness of 4 mm. Then, the waterproof layer is sewn and assembled with the obtained heat-insulating layer to obtain the lightweight greenhouse composite heat-insulating quilt.

[0037] Example 2 A lightweight greenhouse composite heat-insulating quilt includes two layers of waterproof layers and one layer of heat-insulating layer. The heat-insulating layer is located between the two waterproof layers. The waterproof layer is made of PVC waterproof cloth with a thickness of 1.6 mm. The heat-insulating layer comprises the following raw materials in parts by weight: 85 kg of polyurethane, 8 kg of modified silica aerogel, 1.2 kg of composite flame retardant, and 25 kg of foam stabilizer. The foam stabilizer is EPP-112 produced by Evonik Specialties (Shanghai) Co., Ltd. The modified silica aerogel is the modified silica aerogel prepared in Preparation Example 2, and the composite flame retardant is the composite flame retardant prepared in Preparation Example 8.

[0038] The preparation method of the above lightweight greenhouse composite heat-insulating quilt includes the following steps: after mixing polyurethane, modified silica aerogel, and composite flame retardant, a foam stabilizer is added and foaming is carried out to form a plate-shaped heat-insulating layer with a thickness of 7 mm. Then, the waterproof layer is sewn and assembled with the obtained heat-insulating layer to obtain the lightweight greenhouse composite heat-insulating quilt.

[0039] Example 3 The difference between Example 3 and Example 1 is that the modified silica aerogel is the modified silica aerogel prepared in Preparation Example 3.

[0040] Example 4 The difference between Example 4 and Example 1 is that the modified silica aerogel is the modified silica aerogel prepared in Preparation Example 4.

[0041] Example 5 The difference between Example 5 and Example 1 is that the modified silica aerogel is the modified silica aerogel prepared in Preparation Example 5.

[0042] Example 6 The difference between Example 6 and Example 1 is that the modified silica aerogel is the modified silica aerogel prepared in Preparation Example 6.

[0043] Example 7 The difference between Example 7 and Example 1 is that the composite flame retardant is the composite flame retardant prepared in Preparation Example 9.

[0044] Example 8 The difference between Example 8 and Example 1 is that the composite flame retardant is the composite flame retardant prepared in Preparation Example 10.

[0045] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that modified silica aerogel was not added in Comparative Example 1.

[0046] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the composite flame retardant was not added in Comparative Example 2.

[0047] Testing Method Composite thermal insulation cotton was prepared according to the raw materials and methods of Examples 1 - 8 and Comparative Examples 1 - 2, and its thermal insulation performance, limiting oxygen index and tensile strength were tested. The thermal insulation performance was tested with reference to "GB / T 11048 - 1989 Testing of Thermal Insulation Performance of Textiles"; the oxygen index was tested using an oxygen index tester and according to the GB / T 2406 - 1980 standard for a spline with dimensions of 130 mm × 6.5 mm × 3 mm; the tensile strength of the composite thermal insulation cotton was tested using a universal testing machine, and the results were recorded in Table 1.

[0048] Table 1 Performance Test of Composite Thermal Insulation Cotton Project Heat preservation rate / % Oxygen index / % Tensile strength / MPa Example 1 92 32 3.62 Example 2 96 31 4.12 Example 3 91 30 4.46 Example 4 92 31 4.52 Example 5 95 30 4.59 Example 6 94 32 4.61 Example 7 91 27 3.26 Example 8 92 26 3.31 Comparative Example 1 76 25 3.01 Comparative Example 2 91 19 3.26 It can be seen from Table 1, Examples 1 - 2 and Comparative Examples 1 - 2 that the composite thermal insulation quilts prepared in Examples 1 - 2 have good thermal insulation performance, tensile strength and flame retardant performance. In Examples 1 - 2, modified silica aerogel and composite flame retardant were added to the polyurethane. The modified silica aerogel is polyethylene glycol / silica aerogel. When the temperature changes, polyethylene glycol can undergo a phase change and absorb and release heat to maintain the temperature stability. Silica aerogel restricts polyethylene glycol, making it difficult for polyethylene glycol to leak during the phase change. The composite flame retardant can effectively improve the flame retardant performance of the composite thermal insulation quilt. At the same time, the addition of carbon microspheres can further improve the mechanical strength of the composite thermal insulation quilt.

[0049] Compared with Examples 1 - 2, in Comparative Example 1, modified silica aerogel was not added, and both the thermal insulation performance and tensile strength of Comparative Example 1 decreased, indicating that modified silica aerogel can not only improve the thermal insulation performance but also enhance the mechanical strength of the composite thermal insulation quilt, increase its tensile strength and enhance its durability. In Comparative Example 2, the composite flame retardant was not added, and both the flame retardant performance and tensile strength of Comparative Example 2 decreased, indicating that the composite flame retardant can not only improve the flame retardant performance but also enhance the mechanical properties of the composite thermal insulation quilt.

[0050] Compared with Examples 1-2, the tensile strength of Examples 3-4 is improved. When the modified silica aerogel used in Examples 3-4 is prepared, polyester fibers are added. Polyester fibers have good mechanical properties. Dispersing the polyester fibers in the modified silica aerogel can improve the strength of the modified silica aerogel skeleton, thereby enhancing the mechanical strength of the modified silica aerogel, further enhancing the mechanical strength of the composite thermal insulation quilt, increasing its tensile strength, and at the same time reducing the leakage of polyethylene glycol during the processing of the modified silica aerogel, thus improving the thermal insulation performance of the composite thermal insulation quilt.

[0051] Compared with Examples 1-2, the thermal insulation performance and tensile strength of Examples 5-6 are both improved. When the modified silica aerogel used in Examples 5-6 is prepared, hexamethyldisilazane is also added. Hexamethyldisilazane can promote the formation of a more complete silica aerogel skeleton, thereby effectively improving the strength of the modified silica aerogel, reducing the loss of polyethylene glycol, improving the thermal insulation performance of the composite thermal insulation quilt, and at the same time increasing the tensile strength of the composite thermal insulation quilt.

[0052] Compared with Examples 1-2, the flame retardant performance of Examples 7-8 decreases. When the composite flame retardant used in Examples 7-8 is prepared, the concentration of magnesium chloride is changed. The content of magnesium chloride affects the amount of magnesium hydroxide generated. When the concentration of magnesium chloride decreases, the content of magnesium hydroxide deposited on the surface of carbon microspheres is low, resulting in a decrease in the flame retardant performance of the composite flame retardant. When the concentration of magnesium chloride increases, the content of magnesium hydroxide deposited on the surface of carbon microspheres increases, and the deposition is uneven, resulting in poor coating of magnesium hydroxide, thus affecting the synergistic effect between magnesium hydroxide and carbon microspheres in the composite flame retardant, and decreasing the flame retardant performance of the composite thermal insulation quilt.

[0053] This specific embodiment is only an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A lightweight greenhouse composite insulation quilt, characterized by: The invention comprises two waterproof layers and a heat-insulating layer, wherein the heat-insulating layer is located between the two waterproof layers, and the heat-insulating layer comprises the following raw materials in parts by weight: 60-85 parts of polyurethane, 5-8 parts of modified silica aerogel, 0.5-1.2 parts of composite flame retardant, and 15-25 parts of foam stabilizer.

2. The lightweight greenhouse composite insulation quilt according to claim 1, characterized in that: The modified silica aerogel is polyethylene glycol / silicon dioxide aerogel.

3. The lightweight greenhouse composite insulation quilt according to claim 1, characterized in that: The preparation method of the polyethylene glycol / silicon dioxide aerogel comprises: mixing tetraethyl orthosilicate, water and ethanol, stirring at 55-60° C. for 1 hour, adjusting the pH value to 2-3 with 37wt% hydrochloric acid, maintaining the temperature at 55-60° C. and stirring for 1.5-2 hours, adding 10wt% ammonia water to adjust the pH value to 6-7 to obtain a sol, adding polyethylene glycol to the sol, continuing to stir to obtain a wet gel, drying the wet gel at 80-85° C. for 11-12 hours, and crushing to obtain the polyethylene glycol / silicon dioxide aerogel.

4. The lightweight greenhouse composite insulation quilt according to claim 1, characterized in that: Before adding polyethylene glycol to the sol, the sol is further treated as follows: polyester fiber is added to the sol and dispersed uniformly by ultrasonication.

5. The lightweight greenhouse composite insulation quilt according to claim 1, characterized in that: Before adding polyethylene glycol to the sol, hexamethyldisilazane is also added, and the added amount of hexamethyldisilazane is 30-34wt% of ethyl orthosilicate.

6. The lightweight greenhouse composite insulation quilt according to claim 1, characterized in that: The composite flame retardant comprises magnesium hydroxide and carbon microspheres.

7. The lightweight greenhouse composite insulation quilt according to claim 1, characterized in that: The preparation method of the composite flame retardant comprises the following steps: dispersing carbon microspheres in an alcohol aqueous solution of magnesium chloride, adding a dispersant, and ultrasonically vibrating for 25-30 minutes to obtain a mixed solution, dripping an alcohol aqueous solution of sodium hydroxide into the mixed solution, reacting at 60-65° C. for 18 hours, washing with anhydrous ethanol and water until neutral, and drying at 110-115° C. for 4.5-5 hours to obtain the composite flame retardant.

8. The method for preparing the lightweight greenhouse composite thermal insulation quilt according to any one of claims 1 to 7, characterized in that: The following steps are involved: After mixing polyurethane, modified silica aerogel and composite flame retardant, a foam stabilizer is added and foamed to form a plate-like insulation layer with a thickness of 4-7 mm. The waterproof layer and the prepared insulation layer are sewn and assembled to obtain a lightweight greenhouse composite insulation blanket.