Interlayer composite structure, preparation method and dam

Abstract

The invention discloses an interlayer composite structure, a preparation method and a dam. The interlayer composite structure comprises a base layer, a polyurea coating layer, a transition layer and an aerogel layer which are sequentially overlapped, wherein the coating for constructing the transition layer is composed of a water-based silicone acrylic emulsion and a nanometer aluminum oxide dispersion liquid according to the mass ratio of 1: (0.2-0.5); and a coating for constructing the aerogel layer is a water-based silicone acrylic resin-based aerogel coating. The interlayer composite structure is high in structural stability, the seepage-proofing performance of dam concrete and the heat preservation and heat insulation performance of a dam body can be enhanced when the interlayer composite structure is applied to the dam, and the possibility that cracks are generated on the surface of the dam body is reduced.

Description

Technical Field

[0001] This invention relates to an interlayer composite structure, its preparation method, and a dam, and more particularly to an interlayer composite structure, its preparation method, and a dam that combines high-efficiency waterproofing and low thermal conductivity, belonging to the technical field of building waterproofing and thermal insulation materials. Background Technology

[0002] Dams in hydropower projects are typically made of cement concrete, which is prone to surface cracks due to drying shrinkage and temperature stress. Appropriate and effective insulation and moisture retention measures can significantly reduce the likelihood of crack formation.

[0003] Polyurea waterproof coatings are widely used in building roofs, underground engineering, and other scenarios due to their excellent mechanical properties (tensile strength ≥15MPa), rapid curing (surface drying time <10min), and seamless waterproof characteristics. However, traditional polyurea coatings have a high thermal conductivity (approximately 0.2-0.3W / (m•K)), requiring an additional insulation layer in scenarios requiring thermal insulation, increasing construction costs and thickness. Aerogel coatings, as a new type of thermal insulation material, have ultra-low thermal conductivity (0.02-0.04W / (m•K)) and lightweight properties, but when used alone, they suffer from insufficient mechanical strength (hardness <2H) and weak adhesion to the substrate (cross-cut test ≥2 level), and are susceptible to moisture erosion when directly exposed outdoors, leading to a decrease in thermal insulation performance. Currently, there is no technical solution to achieve integrated waterproofing and thermal insulation by combining polyurea waterproof coatings and aerogel coatings through interlayer lamination. There is an urgent need to develop a structurally stable and performance-synergistic composite coating system to provide good waterproofing and thermal insulation for target structures such as dams. Summary of the Invention

[0004] In view of the shortcomings of the prior art, one of the objectives of this invention is to provide a more stable interlayer composite structure and its preparation method; another objective of this invention is to provide a dam.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: An interlayer composite structure includes a base layer, a polyurea coating layer, a transition layer, and an aerogel layer stacked sequentially; wherein the coating used to construct the transition layer is composed of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.2-0.5; and the coating used to construct the aerogel layer is an aqueous silicone-acrylic resin-based aerogel coating.

[0006] Optionally, the solid content of the aqueous silicone-acrylic emulsion is 40-50 wt%; the solid content of the nano-alumina dispersion is 20-30 wt%.

[0007] Optionally, the coating used to construct the transition layer is composed of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.3-0.4.

[0008] Optionally, the particle size of nano-alumina is 1-100 nm, and more specifically 40-80 nm.

[0009] Optionally, by weight, the waterborne silicone-acrylic resin-based aerogel coating comprises 20-35 parts of aerogel dispersion and 65-80 parts of waterborne silicone-acrylic emulsion; wherein the aerogel dispersion is composed of water and aerogel powder, the aerogel powder content in the aerogel dispersion is 15-20 wt%, and the aerogel powder is silica aerogel; the solid content of the waterborne silicone-acrylic emulsion is 40-50 wt%.

[0010] Optionally, the coating used to construct the polyurea coating layer is a two-component polyurea coating; the two-component polyurea coating includes component A and component B, with a mass ratio of component A to component B of 0.8-1.2:1; by mass, component A includes 60-70 parts of isocyanate prepolymer and 30-40 parts of hydroxyl-terminated polyether, and component B includes 30-40 parts of amine chain extender, 5-10 parts of nano-silica, and 2-5 parts of silane coupling agent. Through the reaction of the amino groups (such as -NH2, -NH-) in the amine chain extender with the active groups (such as isocyanate groups -NCO, epoxy groups) in the isocyanate prepolymer, the molecular chain can be extended, improving the mechanical properties of the polyurea coating layer (such as tensile / tear strength, elasticity, temperature resistance, etc.).

[0011] Optionally, the isocyanate prepolymer includes one or more of diphenylmethane diisocyanate prepolymer, toluene diisocyanate prepolymer, and hexamethylene diisocyanate prepolymer; the hydroxyl-terminated polyether is selected from one or more of polypropylene glycol, polypropylene triol, and polytetrahydrofuran glycol; the amine chain extender includes one or more of ethylenediamine, 1,4-butanediamine, and diethylenetriamine; the particle size of the nano-silica is 50-100 nm; and the silane coupling agent is KH-560.

[0012] Optionally, the polyurea coating layer has a tensile strength ≥18MPa, an elongation at break ≥300%, and an adhesion strength to the substrate ≥1.5MPa.

[0013] Optionally, the thickness of the polyurea coating layer is 0.5-2 mm, more preferably 1-1.5 mm; the thickness of the transition layer is 50-1000 μm, more preferably 200-800 μm; and the thickness of the aerogel layer is 0.3-3 mm, more preferably 0.8-2.5 mm.

[0014] Optionally, the thermal conductivity of the aerogel layer is ≤0.045W / (m・K), and the hydrophobicity is ≥95%; water resistance: no bubbling after 24h immersion.

[0015] Optionally, the base layer is a concrete layer.

[0016] Optionally, the interlayer composite structure further includes a protective layer disposed on the surface of the aerogel layer. Optionally, the protective layer is a transparent protective layer.

[0017] Optionally, the thickness of the protective layer is 30-50 micrometers.

[0018] Optionally, the protective layer is constructed from a fluorocarbon varnish containing nano-titanium dioxide. It reflects over 90% of ultraviolet light (300-400nm), contributing to further improving the weather resistance of the interlayer composite structure (no powdering after 500 hours of accelerated aging). Optionally, the fluorocarbon varnish has a solid content of 15-20wt%.

[0019] Based on the same inventive concept, the present invention also provides: a method for preparing the interlayer composite structure as described above, comprising the following steps: S1. After applying the coating used to construct the polyurea coating layer to the substrate surface, cure for 1-3 hours to obtain the polyurea coating layer; optionally, the coating is applied by a scraper.

[0020] S2. After applying a coating to the surface of the polyurea coating layer to form a transition layer, cure for 25-40 minutes to obtain the transition layer; optionally, the coating is performed by roller coating.

[0021] S3. After coating the surface of the transition layer with a coating material for constructing the aerogel layer, cure for 10-14 hours to obtain an interlayer composite structure; optionally, the coating is performed by a scraper.

[0022] Optionally, before S1, the substrate is pretreated by drying, sanding, and cleaning. Optionally, sanding is performed using an angle grinder; cleaning is performed using a vacuum cleaner.

[0023] Based on the same inventive concept, the present invention also provides: a dam, comprising the interlayer composite structure as described above, wherein the base layer is the dam body.

[0024] In this invention, the coating used to construct the transition layer is composed of water-based silicone-acrylic emulsion and nano-alumina dispersion. Through chemical cross-linking of hydroxyl-siloxane bonds, the adhesion between the polyurea coating layer and the aerogel layer can be enhanced (interlayer peel strength ≥5N / cm), so that the polyurea coating layer and the aerogel layer form a stable composite structure, giving full play to the waterproof and heat-insulating effects.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Gradient Functional Layer Design Polyurea coatings can provide a high-strength waterproof substrate. Introducing nano-silica into the polyurea coating can further enhance its density, resulting in a water absorption rate of ≤0.5%. A transition layer is set between the polyurea coating and the aerogel layer. Through organic-inorganic hybrid crosslinking, the bonding problem between polyurea (polar) and aerogel (weakly polar) is solved, forming a more stable interlayer composite structure and effectively improving its service stability.

[0026] (2) Synergistic efficiency mechanism Waterproof and heat-insulating integrated: The polyurea coating layer blocks the penetration of liquid water, and the aerogel layer isolates the diffusion of gaseous water (water vapor transmission rate ≤ 0.1g / (m²)). 2 •h)) forms a double moisture barrier, effectively improving the waterproof performance of the interlayer composite structure. When applied to dams, it can play a good waterproof role for dams.

[0027] Improved temperature adaptability: The temperature resistance range of the interlayer composite structure of the present invention reaches -40℃ to 150℃, which is superior to that of a single polyurea coating layer (-30℃ to 120℃).

[0028] (3) In the preparation process of the interlayer composite structure of the present invention, the drying time of the transition layer is short and the overall construction cycle is shortened by 40% compared with the traditional composite layer (which usually requires the construction of about 3 polyurea layers).

[0029] (4) Applying the interlayer composite structure of the present invention to dams can enhance the seepage prevention performance of dam concrete and the thermal insulation and heat insulation performance of dam body, and reduce the possibility of cracks on the surface of dam body. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of the interlayer composite structure of the present invention.

[0031] In the diagram, 1-base layer, 2-polyurea coating layer, 3-transition layer, 4-aerogel layer. Detailed Implementation

[0032] The present invention will be described in detail below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0033] Example 1 See Figure 1 The interlayer composite structure of this embodiment includes a base layer, a polyurea coating layer, a transition layer and an aerogel layer stacked sequentially; wherein, the coating used to construct the transition layer is composed of waterborne silicone-acrylic emulsion (purchased from Badifu Group Co., Ltd., RS996AD) and nano-alumina dispersion (purchased from Zhejiang Jiupeng New Materials Co., Ltd.) in a mass ratio of 1:0.4; the coating used to construct the aerogel layer is a waterborne silicone-acrylic resin-based aerogel coating.

[0034] The aqueous silicone-acrylic emulsion has a solid content of 47 wt%; the nano-alumina dispersion has a solid content of 25 wt%.

[0035] By weight, the waterborne silicone-acrylic resin-based aerogel coating is composed of 28 parts of aerogel dispersion and 72 parts of waterborne silicone-acrylic emulsion (purchased from Badifu Group Co., Ltd., RS996AD); wherein, the aerogel dispersion is composed of water and aerogel powder, the aerogel powder content in the aerogel dispersion is 18wt%, and the aerogel powder is silica aerogel.

[0036] The coating used to construct the polyurea coating layer is a two-component polyurea coating; the two-component polyurea coating includes component A and component B, with a mass ratio of component A to component B of 1:1; by mass, component A includes 65 parts of isocyanate prepolymer and 35 parts of hydroxyl-terminated polyether, and component B includes 35 parts of amine chain extender, 8 parts of nano silica and 4 parts of silane coupling agent.

[0037] The isocyanate prepolymer is diphenylmethane diisocyanate; the hydroxyl-terminated polyether is epoxide butane; the amine chain extender is ethylenediamine; the particle size of the nano silica is ≤80nm; and the silane coupling agent is KH-560.

[0038] The polyurea coating layer has a thickness of 1.4 mm, the transition layer has a thickness of 550 micrometers, and the aerogel layer has a thickness of 1.5 mm.

[0039] The base layer is a concrete layer.

[0040] The method for preparing the interlayer composite structure as described above includes the following steps: S1. After applying the coating used to construct the polyurea coating layer to the base surface with a scraper, cure at room temperature for 1.5 hours to obtain the polyurea coating layer; S2. After applying the coating for constructing the transition layer to the surface of the polyurea coating layer by roller coating, cure for 30 minutes to obtain the transition layer; S3. After applying the coating used to construct the aerogel layer to the surface of the transition layer with a scraper, cure for 12 hours to obtain an interlayer composite structure.

[0041] Example 2 Example 1 is repeated, except that the coating used to construct the transition layer is composed of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.3.

[0042] Comparative Example 1 Repeat Example 1, except that no transition layer is provided between the polyurea coating layer and the aerogel layer.

[0043] Comparative Example 2 Example 1 was repeated, except that the coating used to construct the transition layer did not contain nano-alumina dispersion.

[0044] Comparative Example 3 Example 1 was repeated, except that the coating used to construct the transition layer consisted of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.1.

[0045] Example 3 Example 1 was repeated, except that the coating used to construct the transition layer consisted of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.2.

[0046] Example 4 Example 1 is repeated, except that the coating used to construct the transition layer is composed of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.5.

[0047] Comparative Example 4 Example 1 was repeated, except that the coating used to construct the transition layer was composed of an aqueous silicone-acrylic emulsion and a nano-alumina dispersion in a mass ratio of 1:0.7.

[0048] Comparative Example 5 Example 1 is repeated, except that the amount of aerogel dispersion added to the water-based silicone-acrylic resin-based aerogel coating is 40 parts by weight.

[0049] Comparative Example 6 Example 1 is repeated, except that the amount of aerogel dispersion added in the water-based silicone-acrylic resin-based aerogel coating is 0 parts by weight.

[0050] The performance test results of the interlayer composite structures in each embodiment and comparative example are shown in Table 1.

[0051] Table 1

[0052] The bond strength was tested according to standard JG / T157-2009. The water vapor transmission rate was tested according to ASTM E96. Thermal conductivity was measured according to GB / T 10295-2008.

[0053] As shown in the table, by setting a transition layer and controlling its composition, the bonding strength of the interlayer composite structure can be effectively improved, the water vapor transmission rate can be reduced, and excellent thermal insulation performance can be maintained. The amount of nano-alumina dispersion added to the transition layer should not be too low or too high. If the amount is too low, it will be difficult to enhance the bonding strength; if the amount is too high, it will easily lead to embrittlement of the transition layer, thereby reducing the bonding strength and increasing the water vapor transmission rate.

[0054] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. An interlayer composite structure, characterized by, The layer interlaminar composite structure comprises a base layer, a polyurea coating layer, a transition layer and an aerogel layer which are sequentially laminated; wherein the coating for building the transition layer is composed of water-based silicone-acrylate emulsion and nano-alumina dispersion liquid in a mass ratio of 1:0.2-0.5; the coating for building the aerogel layer is water-based silicone-acrylate resin-based aerogel coating.

2. The interlayer composite structure of claim 1, wherein The solid content of the water-based silicone-acrylate emulsion is 40-50wt%; the solid content of the nano-alumina dispersion liquid is 20-30wt%.

3. The interlayer composite structure of claim 1, wherein The coating for building the transition layer is composed of water-based silicone-acrylate emulsion and nano-alumina dispersion liquid in a mass ratio of 1:0.3-0.

4.

4. The interlayer composite structure of claim 1, wherein The water-based silicone-acrylate resin-based aerogel coating comprises, by mass fraction, 20-35 parts of aerogel dispersion and 65-80 parts of water-based silicone-acrylate emulsion; wherein the aerogel dispersion is composed of water and aerogel powder, the content of the aerogel powder in the aerogel dispersion is 15-20wt%, and the aerogel powder is silica aerogel; the solid content of the water-based silicone-acrylate emulsion is 40-50wt%.

5. The interlayer composite structure of claim 1, wherein The coating for building the polyurea coating layer is two-component polyurea coating; the two-component polyurea coating comprises component A and component B, and the mass ratio of component A to component B is 0.8-1.2:1; by mass fraction, component A comprises 60-70 parts of isocyanate prepolymer and 30-40 parts of hydroxyl-terminated polyether, and component B comprises 30-40 parts of amine chain extender, 5-10 parts of nano-silica and 2-5 parts of silane coupling agent.

6. The interlayer composite structure of claim 5, wherein The isocyanate prepolymer comprises one or more of diphenylmethane diisocyanate prepolymer, toluene diisocyanate prepolymer and hexamethylene diisocyanate prepolymer; the hydroxyl-terminated polyether is selected from one or more of polypropylene oxide diol, polypropylene oxide triol and polytetrahydrofuran diol; the amine chain extender comprises one or more of ethylenediamine, 1,4-butanediamine and diethylenetriamine; the particle size of the nano-silica is 50-100nm; and the silane coupling agent is KH-560.

7. The interlayer composite structure according to any one of claims 1 to 6, wherein The thickness of the polyurea coating layer is 0.5-2mm, the thickness of the transition layer is 50-1000 microns, and the thickness of the aerogel layer is 0.3-3mm.

8. The interlayer composite structure according to any one of claims 1 to 6, wherein The base layer is a concrete layer.

9. The method of making an interlayer composite structure according to any one of claims 1 to 8, wherein, The method comprises the following steps: S1, after coating the coating for building the polyurea coating layer on the surface of the base layer, curing for 1-3h to obtain the polyurea coating layer; S2, after coating the coating for building the transition layer on the surface of the polyurea coating layer, curing for 25-40min to obtain the transition layer; S3, after coating the coating for building the aerogel layer on the surface of the transition layer, curing for 10-14h to obtain the layer interlaminar composite structure.

10. A dam, characterized by The layer interlaminar composite structure comprises the layer interlaminar composite structure according to any one of claims 1-8, and the base layer is a dam body of a dam.

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