Preparation method of waste paper regenerated fiber super-hydrophobic anti-icing coating

Abstract

The invention discloses a preparation method of a waste paper regenerated fiber super-hydrophobic anti-icing coating, and relates to a preparation method of an anti-icing coating, and the method comprises the following steps: preparing nano cellulose powder through recycled waste paper, modifying the nano cellulose powder through dopamine hydrochloride, p-phenylenediamine and octadecylamine to form OA-CP-F powder, and compounding the OA-CP-F powder with epoxy resin and an epoxy resin curing agent to form a spraying coating, the curing agent is an epoxy resin common curing agent. The coating with a micro-nano composite structure is formed on the surface of a base material by adopting a spraying method, the contact angle is as high as 155 degrees, the icing time can be remarkably prolonged to 358s (-20 DEG C), an ice layer on the surface of the coating is loose frost ice and is extremely easy to fall off, the icing risk of various materials can be remarkably reduced, and the coating is suitable for the fields of aerospace, electric power facilities and the like.

Description

Technical Field

[0001] The present invention relates to a preparation method of a hydrophobic coating, and particularly to a preparation method of a superhydrophobic anti-icing coating for recycled fiber from waste paper. Background Art

[0002] Nowadays, the icing phenomenon caused by severe weather seriously threatens the safety of materials in fields such as power facilities and aerospace. Therefore, it is urgent to improve the anti-icing ability of the material surface. Traditional anti-icing methods (such as manual de-icing, heating de-icing, and chemical snow melting agents) have problems such as high energy consumption and large environmental pollution. Superhydrophobic coatings have attracted the interest of many researchers due to their superhydrophobic properties on the surface, and provide innovative ideas for the research on anti-icing of material surfaces.

[0003] The anti-icing mechanism of superhydrophobic coatings mainly depends on the synergistic effect of their micro-nano rough structure and low surface energy components. The micro-nano structure can intercept the air layer, reduce the solid-liquid contact area, and delay the freezing of droplets; the low surface energy components promote the contraction of droplets and reduce the accumulation of surface water films, thereby reducing the ice layer adhesion. However, existing superhydrophobic coatings generally have problems such as poor mechanical stability and easy wear of the micro-nano structure, which limit their practical applications. Although some studies have improved the coating durability by adding adhesive layers or repair agents, most are limited to two-dimensional surface modification and have not fundamentally solved the contradiction between structural stability and functional durability. Therefore, developing a superhydrophobic anti-icing coating with low cost, high stability, and easy large-scale preparation has important scientific significance and application value. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of a superhydrophobic anti-icing coating for recycled fiber from waste paper. This method recycles waste paper and gives it a new use way, reduces the cost of superhydrophobic materials, and prepares a superhydrophobic anti-icing coating by a simple one-step spraying method, greatly improving the hydrophobic and anti-icing performance of the coating, which is beneficial to reducing the corrosion and damage of materials caused by icing and has great application value.

[0005] The technical solution of the present invention is as follows: A preparation method of a superhydrophobic anti-icing coating for recycled fiber from waste paper, the method comprising the following steps: (1) Soak the recycled waste paper in a NaOH solution, stir, centrifuge and dry to obtain cellulose powder, and further crush the cellulose using a planetary ball mill to prepare nano-scale cellulose powder; (2) Add nano - cellulose powder into the Tris - HCl buffer solution mixed with dopamine hydrochloride, stir at room temperature for 12 hours, and obtain P@F powder through centrifugation, washing, and freeze - drying. Add P@F powder, p - phenylenediamine, and 1,3,5 - benzenetricarboxaldehyde into 1,4 - dioxane, mix evenly, add acetic acid, stir for 1 hour, and obtain CP@F powder through centrifugation, washing, and drying. Add CP@F powder and octadecylamine into absolute ethanol, mix evenly, stir for 24 hours, and prepare OA - CP@F powder through centrifugation, washing, and drying. (3) Disperse OA - CP@F powder, epoxy resin, and curing agent in a solvent, spray evenly onto the surface of the substrate, and heat - cure to obtain a super - hydrophobic anti - icing coating.

[0006] In the preparation method of the waste - paper recycled fiber super - hydrophobic anti - icing coating described above, in step (1), the concentration of the NaOH solution is 0.15 - 0.25 mol / L, preferably 0.2 mol / L; the stirring time is 10 - 16 hours, preferably 12 hours; the grinding time is 6 - 10 hours, preferably 8 hours.

[0007] In the preparation method of the waste - paper recycled fiber super - hydrophobic anti - icing coating described above, in step (2), the mass ratio x:y:z of OA - CP@F powder, epoxy resin, and curing agent is (60 - 140):100:(25 - 50), preferably 100:100:33.

[0008] In the preparation method of the waste - paper recycled fiber super - hydrophobic anti - icing coating described above, in step (3), the curing agent is polyetheramine D230, polyetheramine D400, polyetheramine D2000, phthalic anhydride, isophorone diamine, preferably polyetheramine D230; the solvent is ethyl acetate, xylene, acetone, and tetrahydrofuran, preferably tetrahydrofuran; the spray gun pressure is 0.1 - 0.5 MPa, the distance between the spray gun and the substrate is 5 - 20 cm, preferably 0.1 Mpa and the distance is 10 cm; the coating thickness is 50 - 500 μm, preferably 200 μm; the substrate is Q - 235 steel, glass, aluminum plate, preferably Q - 235 steel; heat - cure at 45 - 80 °C for 20 - 30 hours, preferably heat at 60 °C and cure for 24 h.

[0009] The present invention has the following beneficial effects: Waste - paper resource utilization and low - cost preparation The method of the present invention first converts waste paper into a nano - cellulose substrate, and realizes the efficient extraction and nano - sizing of cellulose through an alkali treatment - ball - milling process, which can significantly reduce the raw material cost and provide a new way for the large - scale production of biomass - based super - hydrophobic coatings.

[0010] 2. Multi - level modification and surface energy gradient design A multi-level modification process using dopamine hydrochloride coating, in-situ growth of covalent organic framework (COF), and modification with long-chain alkylamine (octadecylamine) was employed to construct a synergistic system of "micro-nano rough structure + low surface energy chemical groups", with a contact angle exceeding 150° and low ice adhesion, breaking through the bottleneck that it is difficult to balance the mechanical stability and hydrophobicity of traditional coatings.

[0011] 3. Anti-icing performance and engineering application advantages Ice crystals on the coating surface grow in the form of loose frost ice, and the icing time is extended to 358 s (-20°C). The ice layer can spontaneously fall off under natural conditions, which is applicable to the surfaces of power cables, drone wings, and transportation facilities, and can significantly reduce the corrosion risk and maintenance cost caused by icing. Brief description of the drawings

[0012] Figure 1 It is a schematic diagram of the recycled waste paper treatment in Example 1; Figure 2 It is a schematic diagram of the modification process of nano-cellulose powder in Example 1; Figure 3 It is a contact angle test result diagram of the superhydrophobic anti-icing coating prepared in Example 1; Figure 4 It is a contact angle test result diagram of the coating prepared in Comparative Example 1; Figure 5 It is a comparison diagram of icing between the original plate and the superhydrophobic anti-icing coating prepared in Example 1. Detailed implementation manners

[0013] The principles and features of the present invention are described below. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention. For those not specified in the examples, they are carried out under conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0014] Table 1 Formulation and process conditions of the examples Number OA-CP@F E51 D230 Spraying pressure (Mpa) Spraying distance (cm) Curing temperature (℃) Curing time (h) Example 1 100 100 33 0.2 20 60 24 Example 2 50 100 25 0.1 15 80 20 Example 3 150 100 50 0.3 10 50 30 Example 1

[0015] A superhydrophobic anti-icing coating based on recycled paper, and its preparation method includes the following steps: (1) As Figure 1 shown, the recycled waste paper is crushed to obtain nano-cellulose powder; (2) As Figure 2 shown, the nano-scale fiber powder is modified to obtain OA-CP@F powder.

[0016] (3) Add OA-CP@F powder, epoxy resin, and curing agent into an appropriate amount of tetrahydrofuran in a mass ratio of 100:100:33, mix evenly, pour into a spray gun, and spray evenly onto the surface of the substrate (Q-235 steel sheet) at a distance of 20 cm under a pressure of 0.2 Mpa. Heat to 60 °C and cure for 24 h to obtain a superhydrophobic anti-icing coating. Example 2

[0017] A superhydrophobic anti-icing coating, and its preparation method includes the following steps: (1) Crush recycled waste paper to obtain nanocellulose powder; (2) Modify the nanoscale fiber powder to obtain OA-CP@F powder.

[0018] (3) Add OA-CP@F powder, epoxy resin, and curing agent into an appropriate amount of tetrahydrofuran in a mass ratio of 50:100:25, mix evenly, pour into a spray gun, and spray evenly onto the surface of the substrate (aluminum sheet) at a distance of 15 cm under a pressure of 0.1 Mpa. Heat to 80 °C and cure for 20 h to obtain a superhydrophobic anti-icing coating. Example 3

[0019] A superhydrophobic anti-icing coating, and its preparation method includes the following steps: (1) Crush recycled waste paper to obtain nanocellulose powder; (2) Modify the nanoscale fiber powder to obtain OA-CP@F powder.

[0020] (3) Add OA-CP@F powder, epoxy resin, and curing agent into an appropriate amount of tetrahydrofuran in a mass ratio of 150:100:50, mix evenly, pour into a spray gun, and spray evenly onto the surface of the substrate (glass sheet) at a distance of 10 cm under a pressure of 0.3 Mpa. Heat to 50 °C and cure for 30 h to obtain a superhydrophobic anti-icing coating.

[0021] Comparative Example 1 A coating, and its preparation method includes the following steps: (1) Add epoxy resin and curing agent into an appropriate amount of tetrahydrofuran in a mass ratio of 3:1, mix evenly, pour into a spray gun, and spray evenly onto the surface of the substrate (Q-235 steel sheet) at a distance of 20 cm under a pressure of 0.1 Mpa. Heat to 60 °C and cure for 24 h to obtain a coating.

[0022] Test Example 1 (1) The contact angle test results of the coatings prepared in Example 1 and Comparative Example 1 are respectively as Figure 3 and Figure 4As shown. The results show that the water contact angle of the coating prepared in Example 1 (155°) is significantly greater than that of Comparative Example 1 (92°), indicating that the papilla structure on the surface of the superhydrophobic anti-icing coating is beneficial to the hydrophobic performance of the coating.

[0023] (2) The as-received Q-235 steel sheet and the superhydrophobic anti-icing coating prepared in Example 1 were placed on a cold stage for ice formation experiments. The results are as Figure 5 shown. The results show that under the condition of -20 °C, the ice formation time of the as-received sheet is 107 s, and the ice formation time of the coating in Example 1 reaches 358 s, which is extended by 251 s. Moreover, the form of the ice layer on the surface of the coating in Example 1 is mainly frost ice, and the structure is loose. The frost ice with this structure has a small bonding force with the substrate material and is more likely to fall off.

[0024] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, or improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a super-hydrophobic anti-icing coating of waste paper recycled fiber, characterized in that: The method comprises the following steps: (1) Soaking the recycled waste paper in a NaOH solution, stirring, centrifuging and drying to obtain cellulose powder, and further crushing the cellulose using a planetary ball mill to prepare nano-scale cellulose powder; (2) Add nanocellulose powder to a Tris-HCl buffer solution mixed with dopamine hydrochloride, stir at room temperature for 12 hours, centrifuge, wash and freeze-dry to obtain P@F powder; add P@F powder, p-phenylenediamine and 1,3,5-trisaldehyde to 1,4-dioxane and mix evenly, add acetic acid, stir for 1 hour, centrifuge, wash and dry to obtain CP@F powder; add CP@F powder and octadecylamine to anhydrous ethanol, mix evenly, stir for 24 hours, centrifuge, wash and dry to obtain OA-CP@F powder; (3) OA-CP@F powder, epoxy resin and curing agent are dispersed in a solvent, sprayed evenly onto the surface of the substrate, and heated and cured to obtain a superhydrophobic anti-icing coating.

2. The method for preparing a super-hydrophobic anti-icing coating of waste paper recycled fiber according to claim 1, characterized in that: In the step (1), the concentration of the NaOH solution is 0.15-0.25 mol / L, preferably 0.2 mol / L; the stirring time is 10-16 hours, preferably 12 hours; and the crushing time is 6-10 hours, preferably 8 hours.

3. The method for preparing a super-hydrophobic anti-icing coating of waste paper recycled fiber according to claim 1, characterized in that: In the step (2), the mass ratio x:y:z of OA-CP@F powder, epoxy resin and curing agent is (60-140):100:(25-50), preferably 100:100:

33.

4. The method for preparing a super-hydrophobic anti-icing coating of waste paper recycled fiber according to claim 1, characterized in that: In the step (3), the curing agent is polyetheramine D230, polyetheramine D400, polyetheramine D2000, phthalic anhydride, isophorone diamine, preferably polyetheramine D230; the solvent is ethyl acetate, xylene, acetone and tetrahydrofuran, preferably tetrahydrofuran; the spray gun pressure is 0.1-0.5 MPa, the distance between the spray gun and the substrate is 5-20 cm, preferably 0.1 MPa, the distance is 10 cm; the coating thickness is 50-500 μm, preferably 200 μm; the substrate is Q-235 steel, glass, aluminum plate, preferably Q-235 steel; the curing is heated to 45-80°C for curing, and the curing is performed for 20-30 hours, preferably heated to 60°C for curing for 24 hours.

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