Preparation method and application of polyurethane ice-corrosion-resistant coating

Abstract

The invention discloses a preparation method and application of a polyurethane ice-corrosion-resistant coating, and the preparation method comprises the following steps: preparing a component A which comprises isocyanate, polyol, a catalyst and a defoaming agent; preparing a component B, wherein the component B comprises polyol, a chain extender, a fluorine-containing end-capping reagent and titanium dioxide; the component A and the component B are mixed and then subjected to mold pressing, curing and forming, and the ice-corrosion-resistant polyurethane coating is obtained. The material is simple in preparation process and low in cost, and large-scale batch production can be realized. The prepared polyurethane ice-corrosion-resistant coating has excellent mechanical properties, waterproof and anti-icing properties, low water absorption, and excellent alkali resistance and wide temperature range stability.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and in particular to a method for preparing and using a polyurethane anti-icing coating. Background Technology

[0002] Pumped-storage power stations with rockfill dams in high-altitude (-40℃) face severe ice damage threats: the ice thrust generated by the freezing of the reservoir water can reach several megapascals, and combined with the periodic ice pull-out force generated when the ice melts, it can easily cause structural cracking of the concrete panels in the water level fluctuation zone, and at the same time cause the joint sealing materials to fail due to repeated freeze-thaw cycles. The polyurea coatings widely used in traditional anti-icing solutions have the following defects: insufficient low-temperature toughness, easy to freeze-swell and delaminate; high water absorption rate, which leads to peeling after long-term immersion in water; and the coating is easily punctured by ice thrust and ice rubbing.

[0003] Current anti-icing technologies in the engineering field mainly rely on two core approaches: first, delaying the icing process by constructing superhydrophobic surfaces; second, reducing the interfacial ice adhesion strength through chemical modification or physical regulation, allowing the ice layer to detach autonomously using natural external forces such as wind, water flow, and its own weight. Fluorides, due to their extremely low dielectric constant and surface migration properties, can effectively weaken the electrostatic interaction between ice and the substrate, and their anti-icing performance is less affected by environmental climate, making them key to improving the anti-icing performance of materials. However, existing fluorinated modified polyurethane coatings exhibit mechanical strength degradation at extreme low temperatures, and the mechanism by which fluorine content regulates performance over a wide temperature range remains unclear. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method for preparing polyurethane anti-icing coating and its application for waterproofing and antifreeze of the surface layer of concrete-faced rockfill dams in high-altitude and cold regions.

[0005] According to a first aspect of the present invention, a method for preparing a polyurethane anti-icing coating is provided, comprising: preparing component A, wherein component A comprises isocyanate, polyol, catalyst and defoamer; preparing component B, wherein component B comprises polyol, chain extender, fluorinated end-capping agent and titanium dioxide; and mixing component A and component B and then molding and curing to obtain a polyurethane anti-icing coating.

[0006] In some exemplary embodiments, the step of preparing component A further includes: heating the polyol to 105°C to 115°C and vacuum dehydrating it for 1.5 to 2 hours.

[0007] In some exemplary embodiments, the step of preparing component A further includes: cooling the polyol to 50°C to 60°C after the reaction is complete, and adding the isocyanate, the catalyst and the defoamer in a nitrogen atmosphere.

[0008] In some exemplary embodiments, the step of preparing component A further includes: adding all of component A and heating to 65°C to 75°C, and after the reaction slows down, raising the temperature to 90°C to 95°C and reacting for 2.5 to 3 hours.

[0009] In some exemplary embodiments, the step of preparing component A further includes: cooling and sealing the product obtained from the reaction of component A for storage.

[0010] In some exemplary embodiments, the amount of the fluorinated capping agent added in the step of preparing component B is 0-7%.

[0011] In some exemplary embodiments, the step of preparing component B further includes: sequentially adding the polyol, the chain extender, the fluorinated end-capping agent and the titanium dioxide, stirring until homogeneous, and then sealing and storing the reaction product.

[0012] In some exemplary embodiments, the step of mixing component A and component B and then molding and curing to obtain a polyurethane anti-icing coating further includes: mixing and stirring component A and component B for 1 min to 2 min, pouring the mixture into a mold, and molding it at a high temperature of 100℃ to 105℃ for 25 min to 35 min using a flat vulcanizing machine.

[0013] In some exemplary embodiments, the step of mixing component A and component B and then molding and curing to obtain a polyurethane anti-icing coating further includes: molding component A and component B together, removing them, and then placing them in a forced-air drying oven at 100°C to 105°C for 9 to 11 hours for curing.

[0014] According to a second aspect of the present invention, a polyurethane anti-icing coating is provided for use, wherein the polyurethane anti-icing coating is prepared by the above-described method for preparing polyurethane anti-icing coating, and the polyurethane anti-icing coating is applied to the ice erosion protection in the water level fluctuation zone of a concrete-faced rockfill dam of a pumped storage power station.

[0015] The material preparation process of this invention is simple and low-cost, enabling large-scale mass production. The prepared polyurethane anti-icing coating possesses excellent mechanical properties, waterproof and anti-icing performance, low water absorption, and excellent alkali resistance and wide temperature range stability. In practical applications, the accompanying construction process ensures complete coating adhesion, preventing peeling, frost heave, or damage after wintering, significantly reducing ice pull-out damage, and overcoming the low-temperature embrittlement limitations of traditional dam surface protection materials. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of the preparation method of the polyurethane anti-icing coating of the present invention.

[0018] Figure 2 The diagram shows the tensile strength and elongation at break of F-LSPU with different contents of fluorinated end-capping agent in this embodiment of the invention.

[0019] Figure 3 The contact angle and surface energy diagrams of F-LSPU with different fluorinated end-capping agent contents are shown in the embodiments of the present invention.

[0020] Figure 4 This is a graph showing the water absorption rate of F-LSPU with different fluorinated end-capping agent contents according to an embodiment of the present invention.

[0021] Figure 5 The attached diagram shows F-LSPUs with different fluorinated end-capping agent contents according to embodiments of the present invention. Detailed Implementation

[0022] The essence of the technical solution of this invention will be explained in detail below.

[0023] This invention proposes a method for preparing and using a polyurethane anti-icing coating for waterproofing and frost protection of the surface of concrete-faced rockfill dams in high-altitude and cold regions.

[0024] Figure 1 This is a flowchart illustrating the preparation method of the polyurethane anti-icing coating of the present invention. Figure 1 As shown, the preparation method of the polyurethane anti-icing coating of the present invention includes the following steps.

[0025] In step S1, component A is prepared, which includes isocyanate, polyol, catalyst and defoamer.

[0026] Preferably, during the preparation of component A, the polyol is heated to 105℃~115℃ and vacuum dehydrated for 1.5~2h; after the reaction of the polyol is completed, it is cooled to 50℃~60℃, and isocyanate, catalyst, and defoamer are added in a nitrogen environment; after adding all of component A, namely isocyanate, polyol, catalyst, and defoamer, the temperature is first raised to 65℃~75℃, and after the reaction slows down, the temperature is raised to 90℃~95℃ and the reaction is carried out for 2.5h~3h.

[0027] Preferably, the product obtained from the reaction of component A is stored in a cool, sealed container.

[0028] In step S2, component B is prepared, which includes a polyol, a chain extender, a fluorinated end-capping agent, and titanium dioxide.

[0029] Preferably, during the preparation of component B, polyol, chain extender, fluorinated end-capping agent and titanium dioxide are added sequentially and then stirred thoroughly.

[0030] Preferably, the amount of fluorinated capping agent added to component B is 0-7%.

[0031] Preferably, the product obtained from the reaction of component B is stored in a sealed container.

[0032] In step 103, the components A and B are mixed and then molded and cured to obtain a polyurethane anti-icing (F-LSPU) coating.

[0033] Preferably, after mixing and stirring component A and component B for 1 to 2 minutes, the mixture is quickly poured into a mold and molded using a flat vulcanizing machine at a high temperature of 100°C to 105°C for 25 to 35 minutes.

[0034] Preferably, after molding, components A and B are removed and placed in a forced-air oven at 100°C for 9 to 11 hours to cure.

[0035] The material preparation process of this invention is simple and low-cost, enabling large-scale mass production. The prepared polyurethane anti-icing coating possesses excellent mechanical properties, waterproof and anti-icing performance, low water absorption, and excellent alkali resistance and wide temperature range stability. In practical applications, the accompanying construction process ensures complete coating adhesion, preventing peeling, frost heave, or damage after wintering, significantly reducing ice pull-out damage, and overcoming the low-temperature embrittlement limitations of traditional dam surface protection materials.

[0036] The following specific embodiments describe the technical solution of this invention, but the conditions and results described in the implementation do not constitute a limitation on the scope of protection of this application. Furthermore, unless otherwise specified, the experimental methods described in the following embodiments and comparative examples are conventional methods; and unless otherwise specified, the reagents and materials are commercially available.

[0037] Example:

[0038] The preparation method of the polyurethane anti-icing coating in this embodiment includes the following steps.

[0039] (1) Preparation of component A: Accurately weigh a portion of polypropylene glycol 2000 (PPG-2000) into a three-necked flask, heat it to 110°C and dehydrate it under vacuum for 1.5 h, then cool it to 55°C; subsequently, after purging with nitrogen, add all of the dicyclohexylmethane-4,4'-diisocyanate (HMDI) and organotin catalyst (T) in sequence.12 ), defoamer (BHD-702), first heat to 70℃, after the reaction slows down, the temperature is raised to 90℃ and reacted for 3 hours, the resulting product is cooled and sealed for storage (step S1);

[0040] (2) Preparation of component B: Polypropylene glycol 2000 (PPG-2000), 1,4-butanediol (BDO), 1H,1H,2H,2H-perfluorooctanol (6:2FTOH), and titanium dioxide (TiO2) were added to a beaker in sequence and stirred thoroughly. The contents of 6:2FTOH were 0%, 1%, 3%, 5%, and 7%, respectively. The reaction products with different contents of 6:2FTOH were sealed and stored (step S2).

[0041] (3) Place component A and each component B in a beaker and stir quickly for 1.5 min. Then pour it into a mold and mold it using a flat vulcanizing machine at 100°C for 30 min. After taking it out, place it in a forced-air oven at 100°C for 10 h to cure it and obtain the F-LSPU coating (step S3).

[0042] Regarding the products prepared by the method steps of the above embodiments, the inventors performed the following verification and characterization.

[0043] Figure 2 This is a graph showing the tensile strength and elongation at break of F-LSPU with different fluorinated end-capping agent contents according to embodiments of the present invention. Figure 3 The images show the contact angle and surface energy of F-LSPUs with different fluorinated end-capping agent contents according to embodiments of the present invention. Figure 4 This is a graph showing the water absorption rate of F-LSPU with different fluorinated end-capping agent contents according to embodiments of the present invention. Figure 5 These are ice-bonded figures illustrating F-LSPUs with different fluorinated end-capping agent contents according to embodiments of the present invention. In each figure, FT-0, FT-1, FT-3, FT-5, and FT-7 represent 6:2 FTOH contents of 0%, 1%, 3%, 5%, and 7%, respectively.

[0044] like Figure 2 As shown, the content of 6:2 FTOH in component B of this embodiment of the invention has a significant impact on the tensile strength and elongation at break of polyurethane anti-icing (F-LSPU). The fluorinated end-capping agent competitively reacts with some -NCO groups, reducing the crosslinking density, weakening the intermolecular forces, and allowing for freer molecular chain movement, resulting in a continuous decrease in tensile strength, from 12.9 MPa to 7.7 MPa. However, the lower segmental cohesive strength and freer molecular chain movement simultaneously increase the elongation at break of F-LSPU from 433.1% to 514.3%, thus increasing its resistance to icing damage through plastic deformation.

[0045] from Figure 3It can be seen that with the addition of fluorine-containing end-capping agents, the contact angle of the material continuously increases, reaching a maximum of 110.2°, and the surface energy decreases by 12.50 mJ / m compared to the FT-0 surface without fluorine atoms. 2 This is attributed to the surface migration ability of the fluorinated end-capping agent, which significantly improves the hydrophobic properties of the material. Therefore, as... Figure 4 As shown, with the addition of fluorinated end-capping agents, the water absorption rate of the material gradually decreased from 0.72% to 0.44%, which is beneficial for the material to have better durability in harsher and more complex water conditions.

[0046] from Figure 5 It can be seen that with the addition of fluorinated end-capping agent, the ice adhesion strength of the material decreased from 183.7 kPa to 48.7 kPa.

[0047] Furthermore, concrete-faced rockfill dams are typically exposed to an alkaline environment (pH value usually between 12.5 and 13.5) in practical engineering applications. The inventors verified that the alkaline immersion loss rate of the materials in this embodiment of the invention initially decreases and then increases with the increase of the fluorinated end-capping agent. When the end-capping agent content is in the range of 0%-5%, the immersion loss rate decreases from 0.23% to 0.19%. However, when the end-capping agent content is 7%, excessive end-capping agent hinders the chain growth of F-LSPU, reduces the size of the hard segment structure, decreases the intermolecular forces of the material, and weakens its ability to resist alkaline molecules, resulting in an increase in the mass loss rate.

[0048] Furthermore, to adapt to the low-temperature working environment of concrete-faced rockfill dams in frigid regions, F-LSPU materials must possess excellent temperature resistance. The inventors verified that the continuous addition of fluorinated end-capping agents in the embodiments of this invention reduced the material's Tg from -24.3℃ to -31.7℃. Simultaneously, the inventors verified that the TGA curves of F-LSPUs with five different end-capping agent contents showed similar trends; the increase in fluorinated end-capping agents only slightly decreased the material's T5%, T1, and T2; with the addition of fluorinated end-capping agents, the material's high-temperature resistance remained almost unchanged, but its low-temperature resistance significantly improved.

[0049] In summary, the polyurethane anti-icing material prepared according to the embodiments of the present invention possesses excellent mechanical properties, waterproof and anti-icing performance, low water absorption, and low ice adhesion strength. Simultaneously, it exhibits excellent alkali resistance and adaptability to high and low temperatures, providing a material solution for hydropower projects in cold regions that combines low ice adhesion strength with long-term durability.

[0050] The polyurethane anti-icing material developed in this invention underwent field testing on the dam panel of an upper reservoir in a pumped-storage power station in a high-altitude, cold region. Compared to panels without fluorine-modified polyurethane anti-icing material, although some ice still adhered at the water level of the dam panel, it was mostly small in size and exerted a weak force on the dam. Furthermore, the coating on the entire dam surface showed no peeling, flaking, or damage. After one winter of operation, the test demonstrated that the surface protective material of the panel did not exhibit long-term immersion delamination, demonstrating good seepage and anti-icing effects, and is suitable for ice erosion protection in the water level fluctuation zone of concrete-faced rockfill dams in pumped-storage power stations.

[0051] It should be understood that the phrase "an embodiment" or "one embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0052] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0053] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a polyurethane anti-icing coating, characterized in that, include: Prepare component A, which includes isocyanate, polyol, catalyst and defoamer; Component B is prepared, wherein component B comprises a polyol, a chain extender, a fluorinated end-capping agent, and titanium dioxide; as well as The polyurethane anti-icing coating is obtained by mixing component A and component B and then molding and curing.

2. The method for preparing the polyurethane anti-icing coating according to claim 1, characterized in that, The step of preparing component A further includes: The polyol was heated to 105℃~115℃ and vacuum dehydrated for 1.5~2 hours.

3. The method for preparing the polyurethane anti-icing coating according to claim 2, characterized in that, The step of preparing component A further includes: After the reaction of the polyol is completed, it is cooled to 50°C to 60°C, and the isocyanate, the catalyst and the defoamer are added in a nitrogen atmosphere.

4. The method for preparing the polyurethane anti-icing coating according to claim 3, characterized in that, The step of preparing component A further includes: After adding all of component A, heat to 65℃~75℃. After the reaction slows down, raise the temperature to 90℃~95℃ and react for 2.5h~3h.

5. The method for preparing the polyurethane anti-icing coating according to any one of claims 1-4, characterized in that, The step of preparing component A further includes: The product obtained from the reaction of component A is cooled, sealed, and stored.

6. The method for preparing the polyurethane anti-icing coating according to claim 1, characterized in that, The amount of fluorinated capping agent added in the step of preparing component B is 0-7%.

7. The method for preparing the polyurethane anti-icing coating according to claim 1, characterized in that, The step of preparing component B further includes: The polyol, chain extender, fluorinated end-capping agent and titanium dioxide were added in sequence and stirred until homogeneous. The resulting product was then sealed and stored.

8. The method for preparing the polyurethane anti-icing coating according to claim 1, characterized in that, The step of mixing component A and component B and then molding and curing to obtain a polyurethane anti-icing coating further includes: After mixing and stirring component A and component B for 1 to 2 minutes, pour the mixture into a mold and mold it using a flat vulcanizing machine at a high temperature of 100°C to 105°C for 25 to 35 minutes.

9. The method for preparing the polyurethane anti-icing coating according to claim 1, characterized in that, The step of mixing component A and component B and then molding and curing to obtain a polyurethane anti-icing coating further includes: After the components A and B are molded, they are removed and placed in a forced-air drying oven at 100℃~105℃ for 9h~11h for curing.

10. The use of a polyurethane anti-icing coating, characterized in that, The polyurethane anti-icing coating is prepared by the method of any one of claims 1-9, and the polyurethane anti-icing coating is applied to the ice erosion protection of the water level fluctuation zone of the concrete-faced rockfill dam of a pumped storage power station.

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