A fluorine-free super-slip wear-resistant deicing coating and its preparation method

Abstract

The present invention discloses a fluorine-free ultra-slip, wear-resistant deicing coating and a preparation method thereof. The preparation method comprises the following steps: step 1, preparing an epoxy bottle brush prepolymer by mercapto-olefin click chemistry: using KH580 and GMA as raw materials and AIBN as an initiator to prepare the epoxy bottle brush prepolymer; step 2, preparing an epoxy bottle brush modified substrate: pretreating the substrate to expose more hydroxyl groups, and then immersing the substrate in an isopropyl alcohol and deionized water solution of the epoxy bottle brush prepolymer and tetraethoxysilane described in step 1; step 3, reacting amino PDMS on the epoxy bottle brush modified substrate obtained in step 2: ultrasonically dissolving monoamine-terminated PDMS in isopropyl alcohol to form a precursor solution, and immersing the epoxy bottle brush modified substrate obtained in step 2 in the precursor solution. The coating of the present invention has higher wear resistance, longer service life, and reduces ice shear force to 2.4N.

Description

Technical Field

[0001] The present invention relates to the technical field of material chemistry, and in particular to a fluorine-free super-slip wear-resistant deicing coating and a preparation method thereof. Background Art

[0002] Freezing is a common phenomenon in nature. Water molecules slow down at low temperatures and gradually arrange themselves into an orderly, crystalline structure. These orderly water molecules then begin to form a crystal structure, ultimately forming ice. However, ice accumulation has significant impacts on power grid security, aerospace, vehicle operation, petrochemicals, and other industries, necessitating the urgent need to develop new de-icing materials.

[0003] Anti-icing materials are primarily categorized as anti-icing and anti-icing. The former inhibits or delays ice crystal formation, thereby preventing or delaying ice growth and achieving the desired anti-icing effect. However, ice formation can still occur under persistently low temperatures. Anti-icing involves creating a surface with ultra-low shear forces on ice, allowing the ice to be removed by its own gravity. Typical anti-icing materials include Silp and Super-Slip surfaces. The former involves infusing a roughened structure with an oil-based lubricant to create a solid-liquid-liquid ice interface between the solid and ice surfaces. This interface allows for easy ice removal, but de-icing effectiveness decreases with lubricant loss. Super-Slip surfaces are typically created by grafting fluorinated compounds or other low-surface-energy materials onto solid surfaces through CVD or immersion methods. The low surface energy of fluorinated compounds easily repels ice, achieving the desired anti-icing effect. However, the use of fluorinated materials limits their application, and the mechanical durability of the coating remains a concern. Organic-inorganic materials combine the inherent properties of organic materials with the mechanical properties of inorganic materials, compensating for their respective shortcomings and providing great potential for the preparation of wear-resistant coatings. For example, the Si-OH groups in inorganic SiO2 easily condense into Si-O-Si to form a cross-linked network, and the hydroxyl groups on its surface are easily reacted with other organic compounds.

[0004] Film preparation methods include electrostatic self-assembly, sol-gel method, chemical vapor deposition, and magnetron sputtering. Chemical vapor deposition requires high reaction temperatures and a complex operating process, while magnetron sputtering consumes high energy and can cause the substrate to heat. Electrostatic self-assembly is complex and requires a wide range of parameters, such as nanoparticle concentration, charge, and pH value. The sol-gel method is a mature, simple, and efficient method. The present invention utilizes the sol-gel method to combine synthetic organic bottle brushes with inorganic SiO2 to produce an ultra-slip, wear-resistant, and deicing coating. Summary of the Invention

[0005] The purpose of the present invention is to provide a fluorine-free super-slip wear-resistant deicing coating to address the technical defects of the super-slip deicing coating in the prior art, which combines the wear-resistant advantages of organic-inorganic hybrid materials and poly-organic bottle brushes.

[0006] Another object of the present invention is to provide a method for preparing a fluorine-free super-smooth, wear-resistant deicing coating, in which a polyepoxy bottle brush is prepared by mercapto-olefin click chemistry, and then TEOS is introduced to prepare a fluorine-free super-smooth, wear-resistant deicing coating.

[0007] The technical solution adopted to achieve the purpose of the present invention is:

[0008] A method for preparing a fluorine-free super-slip wear-resistant deicing coating comprises the following steps:

[0009] Step 1, preparation of epoxy bottle brush prepolymer via thiol-olefin click chemistry:

[0010] The epoxy bottle brush prepolymer was prepared by using γ-mercaptopropyltriethoxysilane (KH580) and glycidyl methacrylate (GMA) as raw materials and azobisisobutyronitrile (AIBN) as initiator. The structure of the epoxy bottle brush prepolymer is n = 1-8;

[0011] The reaction process of step 1 is:

[0012]

[0013] Step 2: Prepare epoxy bottle brush modified substrate:

[0014] The substrate is pretreated to expose more hydroxyl groups, and then immersed in the isopropyl alcohol and deionized water solution of the epoxy bottle brush prepolymer and tetraethoxysilane described in step 1. The Si-O bonds in the epoxy bottle brush prepolymer and tetraethoxysilane are hydrolyzed to form Si-OH. Then, the epoxy bottle brush prepolymer and tetraethoxysilane form a Si-O-Si cross-linked network. The Si-OH and the exposed hydroxyl groups in the substrate condense to form Si-O-. The unreacted solution on the surface is then rinsed with isopropyl alcohol and dried.

[0015] The reaction process of step 2 is:

[0016]

[0017] Step 3: amino PDMS reacts on the epoxy bottle brush modified substrate obtained in step 2:

[0018] Ultrasonic dissolution of the monoamine-terminated PDMS in isopropanol to form a precursor solution, immersing the epoxy bottle brush-modified substrate obtained in step 2 into the precursor solution, rinsing the unreacted solution on the surface with isopropanol, and drying;

[0019] The reaction process of step 3 is:

[0020]

[0021] In the above technical solution, the substrate is an organic substrate, a metal substrate, a glass substrate, wood or paper, and the organic substrate includes PC or PP.

[0022] In the above technical solution, in step 1, the solvent used to prepare the epoxy bottle brush prepolymer is tetrahydrofuran (THF), γ-mercaptopropyltriethoxysilane (KH580) and glycidyl methacrylate (GMA) are dissolved in tetrahydrofuran (THF) to obtain a mixed solution, nitrogen is introduced to remove oxygen in the mixed solution, and then the temperature is raised to 25°C-60°C, a thermal initiator azobisisobutyronitrile (AIBN) is added, and the reaction is carried out for 4h-12h with magnetic stirring throughout the process.

[0023] In the above technical solution, in step 1, the molar ratio of γ-mercaptopropyltriethoxysilane, glycidyl methacrylate, and tetrahydrofuran is 5:(5-40):180, and the mass of the thermal initiator is 0.2%-1% of the mass of the mixed solution.

[0024] In the above technical solution, in step 1, the molecular weight distribution of the epoxy bottle brush prepolymer is 500-2000, and the molar ratio of the main chain to the side chain in the epoxy bottle brush prepolymer is 1:1 to 1:8, wherein the main chain has 1 triethoxysilyl group as 1 mol, and the side chain has 1 epoxy group as 1 mol.

[0025] In the above technical solution, in step 2, the substrate is a glass substrate, and the glass substrate is placed in a muffle furnace for calcination at a temperature of 100° C. to 450° C. for a calcination time of 1 h to 4 h.

[0026] In the above technical solution, in step 2, the mass ratio of epoxy bottle brush prepolymer, tetraethoxysilane, isopropyl alcohol and deionized water is 1:(2.08-8.32):30:(0.5-4).

[0027] In the above technical solution, in step 2, the immersion time is 12-24 hours, and the drying temperature is 25°C-60°C.

[0028] In the above technical solution, in step 3, the concentration of the precursor solution is 0.1g / 10ml-1g / 10ml.

[0029] Another aspect of the present invention also includes a fluorine-free super-slip wear-resistant deicing coating obtained by the above-mentioned preparation method.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. Compared with existing ultra-slip, wear-resistant deicing coatings, the present invention uses mercapto-olefin click chemistry to prepare epoxy bottle brush prepolymers and a sol-gel method to prepare an organic-inorganic hybrid coating. Since the coating is covalently bonded to the substrate, a cross-linked network is formed between the bottle brushes. Compared with traditional Silp interfaces, this coating has higher wear resistance and a longer service life.

[0032] 2. The fluorine-free, ultra-smooth, wear-resistant deicing coating prepared by the present invention does not contain fluorine compounds, is biocompatible, and is not picky about the substrate. It can be applied to most common materials such as organic substrates (PC / PP, etc.), metal substrates, wood, paper, etc., and can be used in a variety of biological devices including catheters. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The infrared spectrum of the final product (TMPDMS) in step 3 is shown.

[0034] Figure 2 The NMR spectrum of the final product in step 3 is shown.

[0035] Figure 3 The transmittance in Example 1 and blank glass is shown.

[0036] Figure 4 The deicing effect diagram of Example 1 and blank glass is shown.

[0037] Figure 5 The contact angle and contact angle hysteresis graphs of Example 1, Comparative Example 1, and Comparative Example 2 are shown. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] Example 1

[0040] A method for preparing a fluorine-free super-slip wear-resistant deicing coating comprises the following steps:

[0041] Step 1, preparation of epoxy bottle brush prepolymer: At room temperature, 0.005 mmol of γ-mercaptopropyltriethoxysilane (KH580) and 0.020 mmol of glycidyl methacrylate (GMA) were dissolved in 15 ml of tetrahydrofuran (THF), and nitrogen was bubbled through for 30 min to remove oxygen. The temperature was then raised to 60°C, and 0.02 g of azobisisobutyronitrile (AIBN) as a thermal initiator was added. The reaction was allowed to proceed for 12 h with magnetic stirring throughout the reaction.

[0042] Step 2, prepare epoxy bottle brush modified glass substrate: cool the glass slide calcined at 450 ° C for 4 hours in a muffle furnace, immerse it in a mixed solution of 1g epoxy bottle brush prepolymer and 4.16g tetraethoxysilane in 30g isopropanol prepared in the above step 1 for 12-24 hours, take it out, rinse the unreacted solution on the surface with isopropanol, and place it in a 60 ° C oven to dry.

[0043] Step 3: Reaction of amino-terminated PDMS on an epoxy-modified glass substrate: Dissolve monoamine-terminated PDMS in isopropyl alcohol using ultrasonication to form a precursor solution. Immerse the epoxy-modified bottle-brush glass substrate in this precursor solution for 2 hours. Rinse any unreacted surface solution with isopropyl alcohol and dry in a 60°C oven.

[0044] like Figure 1-2 As shown, for epoxy bottle brush prepolymer, the peak at 2942 cm -1 and 2842cm -1 The peak at 910 cm is attributed to the methylene asymmetric and methylene symmetric stretching. -1 Asymmetric stretching of the epoxy group, for the reactant NH2-PDMS, 3322 cm -1 and 3270cm -1 This is attributed to the stretching and bending vibration peaks of primary amine. In the final product TMPDMS, the epoxy group and primary amine group disappear, and the peak at 3290 cm -1 The hydroxyl peak of the reaction is confirmed. However, the -NH- stretching vibration peak should be located at 3300cm -1 , is covered by the hydroxyl peak, while the deformation vibration peak of -NH- should be located at 1500cm -1 The peak is absent from the IR, likely due to a low formation of this bond. The positions of the various hydrogen peaks are shown in the NMR spectrum; all peaks are present, along with a minimal hydroxyl peak at 6.3 ppm and a peak at 3.5 ppm. The remaining unlabeled peaks are likely due to the amino PDMS being a mixture. The mutual confirmation of IR and NMR essentially confirms the successful preparation of the final product.

[0045] Depend on Figure 3 It can be seen that the fluorine-free super-smooth and wear-resistant deicing coating has good transmittance and a certain degree of transmittance-enhancing effect in the visible light range. This is mainly due to the fact that the hydrolysis and condensation of tetraethoxysilane will produce silica particles. Silica has a high refractive index and can effectively reduce the reflection coefficient and increase the transmittance of light.

[0046] Figure 4 The difference between Example 1 and ordinary glass in deicing is shown. The deicing shear force is calculated by the following formula:

[0047] ζ ice =Bγ LV (1+COSθR )

[0048] Where B is the instrument parameter, γ LV is the surface energy of water, and the product of the two can be considered a constant. According to the ice shear force of ordinary glass is 43.2N, the theoretical value of ice shear force converted to Example 1 should be 18.3N, but the actual measured value is 2.4N, which shows that the deicing effect of the coating involved in the present invention is not affected by the receding contact angle (θ R ) is not affected by the coating, but because there is a free-moving PDMS bottle brush on the coating surface, which produces a "liquid-like" phenomenon, so it has excellent deicing properties.

[0049] Comparative Example 1

[0050] The method for forming the fluorine-free, ultra-slip, wear-resistant, and deicing coating in Comparative Example 1 was essentially the same as in Example 1, with the only difference being that the amount of glycidyl methacrylate added in Step 1 during the preparation of the anti-fog coating in Comparative Example 1 was reduced to 0.005 mol. This resulted in too few side chain epoxy groups, and therefore too few amino PDMS groups to react with them, ultimately resulting in a coating with poor slip performance.

[0051] Comparative Example 2

[0052] The method for forming the fluorine-free, ultra-slip, wear-resistant, and deicing coating in Comparative Example 2 was essentially the same as in Example 1, with the only difference being that the amount of glycidyl methacrylate added in Step 1 was reduced to 0.040 mol. This resulted in an excess of side chain epoxy groups, which reacted with an excess of amino PDMS, leading to entanglement between the PDMS chains and ultimately poor coating slip performance.

[0053] Depend on Figure 5 It can be seen that the fluorine-free super-slip wear-resistant deicing coating of Example 1 has the best slip ability, which is obviously related to its grafting density. When the feed ratio is 1 / 1, as shown in Comparative Example 1, its single brush configuration causes its molecules to be able to move only within the horizontal range. When the feed ratio is 1 / 4, as shown in Example 1, this is equivalent to introducing side chains on the basis of a single brush. These side chains can also move freely in the vertical direction, thereby improving the free movement ability of the molecules and improving their slip ability. Example 1 has the highest slip ability and the lowest contact angle hysteresis. However, as the grafting density continues to increase, the chains between molecules are more likely to collide and entangle with each other, such as in Comparative Example 2, which reduces the mobility of the side chains of each molecule, resulting in a decrease in its slip ability.

[0054] Comparative Example 3

[0055] Compared to Example 1, the method for forming the fluorine-free, ultra-slip, wear-resistant deicing coating in Comparative Example 3 is essentially the same as in Example 1, with the only difference being that water is not added in Step 2 of the anti-fog coating preparation process in Comparative Example 3. This results in no dehydration condensation between the siloxanes, and the resulting coating lacks wear resistance.

[0056] Comparative Example 4

[0057] Compared to Example 1, the method for forming the fluorine-free, ultra-slip, wear-resistant deicing coating in Comparative Example 4 was essentially the same as in Example 1, with the only difference being that, in step 2 of the anti-fog coating preparation process, the glass substrate was immersed for 6 hours. This resulted in insufficient reaction of the siloxane with the glass substrate to form a covalent bond, resulting in poor adhesion between the coating and the substrate, ultimately resulting in poor slip performance and loss of wear resistance.

[0058] Comparative Example 5

[0059] Compared to Example 1, the method for forming the fluorine-free, ultra-slip, wear-resistant deicing coating in Comparative Example 5 is essentially the same as in Example 1, with the only difference being that tetraethoxysilane is omitted in Step 2 of the anti-fog coating preparation process. As a result, the coating lacks a cross-linked network, contains no SiO₂, and exhibits poor wear resistance and no anti-reflection effect.

[0060] Comparative Example 6

[0061] Compared to Example 1, the method for forming the fluorine-free, ultra-slip, wear-resistant deicing coating in Comparative Example 6 is essentially the same as in Example 1, with the only difference being that, in Step 3 of the anti-fog coating preparation process, bis-amino-terminated PDMS is added. This causes the bis-amine-terminated PDMS to react with two epoxy groups, resulting in the PDMS losing its free mobility and the coating losing its slip properties.

[0062] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a fluorine-free super-slip wear-resistant deicing coating, characterized in that: The following steps are involved: Step 1, preparation of epoxy bottle brush prepolymer via thiol-olefin click chemistry: The epoxy bottle brush prepolymer was prepared using KH580 and GMA as raw materials and AIBN as initiator. The structure of the epoxy bottle brush prepolymer is as follows: n＝1-8； The reaction process of step 1 is: Step 2: Prepare epoxy bottle brush modified substrate: The substrate is pretreated to expose more hydroxyl groups, and then immersed in the isopropyl alcohol and deionized water solution of the epoxy bottle brush prepolymer and tetraethoxysilane described in step 1. The Si-O bonds in the epoxy bottle brush prepolymer and tetraethoxysilane are hydrolyzed to form Si-OH. Then, the epoxy bottle brush prepolymer and tetraethoxysilane form a Si-O-Si cross-linked network. The Si-OH and the exposed hydroxyl groups in the substrate condense to form Si-O-. The unreacted solution on the surface is then rinsed with isopropyl alcohol and dried. The reaction process of step 2 is: Step 3: amino PDMS reacts on the epoxy bottle brush modified substrate obtained in step 2: Ultrasonic dissolution of the monoamine-terminated PDMS in isopropanol to form a precursor solution, immersing the epoxy bottle brush-modified substrate obtained in step 2 into the precursor solution, rinsing the unreacted solution on the surface with isopropanol, and drying; The reaction process of step 3 is:

2. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, characterized in that: The substrate is an organic substrate, a metal substrate, a glass substrate, wood or paper, and the organic substrate includes PC or PP.

3. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, characterized in that: In the step 1, the solvent used to prepare the epoxy bottle brush prepolymer is THF, KH580 and GMA are dissolved in THF to obtain a mixed solution, nitrogen is introduced to remove oxygen in the mixed solution, and then the temperature is raised to 25°C-60°C, AIBN is added, and the reaction is carried out for 4h-12h with magnetic stirring throughout the process.

4. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 3, characterized in that: In the step 1, the molar ratio of KH580, GMA, and THF is 5:(5-40):180, and the mass of the initiator is 0.2%-1% of the mass of the mixed solution.

5. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, wherein: In step 1, the molecular weight of the epoxy bottle brush prepolymer is distributed in the range of 500-2000, and the molar ratio of the main chain to the side chain in the epoxy bottle brush prepolymer is 1:1 to 1:8, wherein the main chain has 1 triethoxysilyl group as 1 mol, and the side chain has 1 epoxy group as 1 mol.

6. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, characterized in that: In step 2, the substrate is a glass substrate, and the step of pre-treating the substrate is: placing the glass substrate in a muffle furnace and calcining it at a temperature of 100° C. to 450° C. for a time of 1 hour to 4 hours.

7. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, characterized in that: In the step 2, the mass ratio of the epoxy bottle brush prepolymer, tetraethoxysilane, isopropyl alcohol and deionized water is 1:(2.08-8.32):30:(0.5-4).

8. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, wherein: In step 2, the immersion time is 12-24 hours, and the drying temperature is 25° C.-60° C.

9. The method for preparing a fluorine-free super-slip wear-resistant deicing coating according to claim 1, wherein: In step 3, the concentration of the precursor solution is 0.1 g / 10 ml-1 g / 10 ml.

10. A fluorine-free, ultra-slip, wear-resistant deicing coating, characterized in that: The method is obtained by the preparation method according to any one of claims 1 to 9.

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