Fluorine-containing copolymer powder and preparation method thereof, and fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating and preparation method thereof

Abstract

The invention provides fluorine-containing copolymer powder, a preparation method of the fluorine-containing copolymer powder, a fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating and a preparation method of the fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating, and belongs to the technical field of super-hydrophobic materials. The preparation method of the fluorine-containing copolymer powder comprises the following steps: step S10, dissolving a fluorine-containing monomer and a non-fluorine monomer in DMF and / or DMAC according to a ratio of (2-30) wt%: (2-30) wt%, adding (0.5-3) wt% of AIBN, and carrying out a polymerization reaction at 50-90 DEG C for 1-12 h to obtain a fluorine-containing copolymer solution; step S20, pouring the fluorine-containing copolymer solution into water, precipitating and filtering to obtain a precipitate; step S30, repeatedly washing the precipitate with alcohol, and filtering; and step S40, carrying out vacuum drying on the washed precipitate, grinding into powder, and sieving with a 400-mesh sieve to obtain fluorine-containing copolymer powder which does not remain any hydrophilic substance influencing the durability of the coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of super-hydrophobic materials, and in particular relates to a fluorine-containing copolymer powder and a preparation method thereof, and a fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating and a preparation method thereof. Background Art

[0002] Fluoropolymer is a class of organic polymers with CC chain as main chain and one or more fluorine atoms connected to the side chain or branch chain. Due to the strong electronegativity of fluorine atoms, high CF bond energy (about 540kJ / mol) and smaller van der Waals radius, fluorine-containing polymers are endowed with a series of excellent properties, including good thermal stability, weather resistance, chemical inertness, etc. Therefore, fluorine-containing polymer powder coatings with fluorine-containing polymers as main components have excellent thermal stability, weather resistance, chemical inertness, and hydrophobic, oleophobic, anti-fouling and other characteristics. Chinese patent CN109400802A discloses a hydrophobic and oleophobic modifier and a preparation method thereof, and a preparation method of modified powder. First, a fluorine-containing copolymer solution is synthesized by a solution polymerization method, and then the powder to be modified and the fluorine-containing copolymer solution are mixed, evaporated, and dried to obtain a fluorine-containing copolymer modified powder coating, which has good hydrophobic and oleophobic properties, and the raw materials are easy to obtain, non-toxic and harmless, and will not pollute the environment. Chinese patent CN108848281A discloses a method for preparing a fluorinated acrylic polymer coating modified with recycled rubber powder. First, a fluorinated copolymer powder is synthesized by a solution polymerization method. Then, a fluorinated copolymer powder coating is obtained by modifying a fluorinated acrylic polymer with recycled rubber powder. The powder coating has super hydrophobic properties and good high temperature resistance, aging resistance, mechanical properties and adhesion properties.

[0003] Although fluoropolymer powder coatings have excellent low surface energy and chemical corrosion resistance, their adhesion to the substrate is not as good as traditional coatings, and the sealing and impermeability of the coating is poor, resulting in poor wear resistance during use. Therefore, it is necessary to develop a fluoropolymer powder coating with good adhesion and impermeability to improve its service life. Summary of the invention

[0004] The present invention is made to solve the above-mentioned problems, and aims to provide a fluorine-containing copolymer powder and a preparation method thereof, as well as a fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating and a preparation method thereof.

[0005] The invention provides a method for preparing fluorine-containing copolymer powder, which has the following characteristics and comprises the following steps: step S10, dissolving a fluorine-containing monomer and a non-fluorine monomer in DMF and / or DMAC at a ratio of (2-30) wt%: (2-30) wt%, adding (0.5-3) wt% of azobisisobutyronitrile (AIBN), and carrying out polymerization reaction at a temperature of 50 DEG C-90 DEG C for 1-12 hours to obtain a fluorine-containing copolymer solution; step S20, pouring the fluorine-containing copolymer solution into water, and obtaining a precipitate through precipitation and filtration; step S30, repeatedly washing the precipitate with alcohol and filtering to obtain a washed precipitate; step S40, vacuum drying the washed precipitate, grinding it into powder, and passing it through a 400-mesh sieve to obtain a fluorine-containing copolymer powder.

[0006] The method for preparing the fluorine-containing copolymer powder provided by the present invention may also have the following characteristics: wherein, in step S10, the fluorine-containing monomer is selected from any one or more of perfluorononylethyl methacrylate, perfluorononylethyl acrylate, perfluorononylethylene, perfluorooctylethyl acrylate, perfluorooctylethyl methacrylate, perfluorooctylethylene, dodecafluoroheptyl methacrylate, dodecafluoroheptyl acrylate, perfluorohexylethyl acrylate, perfluorohexylethyl methacrylate, perfluorohexylethylene, perfluorobutylethyl methacrylate, perfluorobutylethyl acrylate, perfluorobutylethylene, hexafluorobutyl methacrylate, and hexafluorobutyl acrylate.

[0007] The method for preparing the fluorine-containing copolymer powder provided by the present invention may also have the following characteristics: wherein, in step S10, the non-fluorine monomer is selected from any one or more of alkyl acrylates having a carbon chain number of 1-18 and alkyl methacrylates having a carbon chain number of 1-18.

[0008] The method for preparing the fluorinated copolymer powder provided by the present invention may also have the following characteristics: wherein, in step S30, the alcohol is any one or more of methanol, ethanol, propanol, and isopropanol, and the washing is repeated with the alcohol for no less than 3 times.

[0009] The present invention also provides a fluorine-containing copolymer powder, which has the following characteristics: it is prepared by the preparation method of the fluorine-containing copolymer powder.

[0010] The present invention provides a method for preparing a fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating, which has the following characteristics and comprises the following steps: S50, brushing an adhesive on the surface of a cement-based material and waiting for it to be semi-dry, referred to as a semi-dry coating; S60, spraying the above-mentioned fluorine-containing copolymer powder on the semi-dry coating and curing it to obtain a fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating.

[0011] The method for preparing the fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating provided by the present invention may also have the following characteristics: wherein, in step S50, the adhesive is 704 organic silicone adhesive, and the semi-drying condition is curing at room temperature for 0.5-1h.

[0012] The method for preparing the fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating provided by the present invention may also have the following characteristics: wherein, in step S60, the curing condition is curing at room temperature for 22-25 hours.

[0013] The present invention also provides a fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating, which has the following characteristics: it is prepared by using the preparation method of the fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating.

[0014] The fluorinated copolymer powder-based super hydrophobic and oleophobic coating provided by the present invention may also have the following characteristics: wherein, the fluorinated copolymer powder-based super hydrophobic and oleophobic coating comprises a hydrophobic and oleophobic low surface energy layer and an impermeable dense layer; the low surface layer is sprayed by the fluorinated copolymer powder and has hydrophobic and oleophobic properties, thereby giving the coating anti-fouling and self-cleaning capabilities; the dense layer is composed of organic silica gel and has high density and high strength after curing, thereby giving the coating excellent anti-penetration ability and mechanical wear resistance.

[0015] Functions and Effects of the Invention

[0016] According to the fluorinated copolymer powder and its preparation method involved in the present invention, as well as the fluorinated copolymer powder-based super hydrophobic oleophobic coating and its preparation method, the preparation method of the fluorinated copolymer powder includes: dispersing the fluorinated monomer and the non-fluorinated monomer in DMF and / or DMAC according to a specific ratio, then adding AIBN, and polymerizing at a specific temperature to obtain a fluorinated copolymer emulsion, introducing the fluorinated copolymer emulsion into water, filtering, washing with alcohol, vacuum drying after filtering, grinding into powder and sieving to obtain a fluorinated copolymer powder. The fluorinated copolymer powder does not have any residual hydrophilic substances that affect the durability of the coating (such as hydrophilic surfactants, the presence of which greatly reduces the durability of the hydrophobic coating).

[0017] In addition, the preparation method of the fluorine-containing copolymer powder is simple, easy to operate, and suitable for large-scale production.

[0018] Further, the fluorinated copolymer powder-based super-hydrophobic and oleophobic coating of the present invention comprises a hydrophobic and oleophobic low surface energy layer and an impermeable dense layer. The low surface layer is sprayed by the fluorinated copolymer powder and has hydrophobic and oleophobic properties, thereby giving the coating anti-fouling and self-cleaning capabilities. The dense layer is composed of organic silica gel, which has high density and strength after curing, giving the coating excellent anti-penetration ability and mechanical wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flowchart of a method for preparing a fluorinated copolymer powder-based super hydrophobic and oleophobic coating according to Example 1 of the present invention;

[0020] Figure 2 This is an infrared spectrum of the fluorinated copolymer powder in Example 2 of the present invention.

[0021] Figure 3 is the hydrogen nuclear magnetic resonance spectrum of the fluorinated copolymer powder in Example 2 of the present invention ( 1 H-NMR). DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following examples and drawings specifically describe the fluorinated copolymer powder and its preparation method, as well as the fluorinated copolymer powder-based super hydrophobic and oleophobic coating and its preparation method.

[0023] Example 1

[0024] This embodiment provides a fluorine-containing copolymer powder and a preparation method thereof, and a fluorine-containing copolymer powder-based super-hydrophobic and oleophobic coating and a preparation method thereof

[0025] Figure 1 It is a flowchart of a method for preparing a fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating according to Example 1 of the present invention.

[0026] like Figure 1 As shown, the preparation method of the fluorinated copolymer powder-based super hydrophobic and oleophobic coating comprises the following steps:

[0027] Step S10, dissolving the fluorine-containing monomer and the non-fluorine-containing monomer in DMF and / or DMAC at (2-30) wt%: (2-30) wt%, adding (0.5-3) wt% azobisisobutyronitrile (AIBN), and polymerizing at a temperature of 50° C.-90° C. for 1-12 hours to obtain a fluorine-containing copolymer solution.

[0028] In this step, the fluorine-containing monomer is selected from any one or more of perfluorononylethyl methacrylate, perfluorononylethyl acrylate, perfluorononylethylene, perfluorooctylethyl acrylate, perfluorooctylethyl methacrylate, perfluorooctylethylene, dodecafluoroheptyl methacrylate, dodecafluoroheptyl acrylate, perfluorohexylethyl acrylate, perfluorohexylethyl methacrylate, perfluorohexylethylene, perfluorobutylethyl methacrylate, perfluorobutylethyl acrylate, perfluorobutylethylene, hexafluorobutyl methacrylate, and hexafluorobutyl acrylate. The non-fluorine-containing monomer is selected from any one or more of alkyl acrylates having a carbon chain number of 1 to 18 and alkyl methacrylates having a carbon chain number of 1 to 18.

[0029] Step S20, mixing water and the fluorine-containing copolymer solution in a mass ratio of (2-10):1, and obtaining a precipitate by precipitation and filtration.

[0030] Step S30, washing the precipitate three times with alcohol and filtering to obtain a washed precipitate. In this step, the alcohol is any one or more of methanol, ethanol, propanol, and isopropanol.

[0031] S40, vacuum drying the washed precipitate at 40°C for 72 hours, grinding it into powder, and passing it through a 400-mesh sieve to obtain a fluorinated copolymer powder.

[0032] S50, the adhesive is adjusted to (0.2-1) L / m 2 The amount of the adhesive is brushed on the surface of the cement-based material and cured at room temperature for 0.5h, which is recorded as the bottom layer. In this step, the adhesive is 704 organic silicone adhesive.

[0033] S60, fluorinated copolymer powder is prepared at a temperature of (100-500) g / m 2 The fluorinated copolymer powder-based super hydrophobic and oleophobic coating was obtained by spraying it on the base layer and curing it at room temperature for 24 hours.

[0034] Example 2

[0035] This embodiment provides a fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating, which is prepared by the preparation method of the fluorine-containing copolymer powder-based super hydrophobic and oleophobic coating of Example 1.

[0036] Specifically, the specific parameters of each step are selected as follows:

[0037] In step S10, the fluorine-containing monomer is 150g of perfluorohexylethyl acrylate, the non-fluorine-containing monomer is 150g of octadecyl methacrylate, the solvent is 1000g of DMAC, the amount of azobisisobutyronitrile (AIBN) is 5g, the polymerization temperature is 80°C, and the polymerization time is 6h; in step S20, the amount of water is 500g, and the amount of the fluorine-containing copolymer solution is 100g; in step S30, the alcohol is ethanol; in step S50, the amount of the adhesive is 0.6L / m 2 In step S60, the amount of fluorinated copolymer powder is 300g / m 2 .

[0038] In the process of preparing the above-mentioned fluorinated copolymer powder-based super hydrophobic and oleophobic coating, step S40 also prepares fluorinated copolymer powder. The fluorinated copolymer powder is tested, and the results are as follows:

[0039] Figure 2 This is an infrared spectrum of the fluorinated copolymer powder in Example 2 of the present invention. Figure 3is the hydrogen nuclear magnetic resonance spectrum of the fluorinated copolymer powder in Example 2 of the present invention ( 1 H-NMR).

[0040] like Figure 2 and Figure 3 As shown, the low surface energy component (powder coating) in the fluorinated copolymer powder-based super hydrophobic and oleophobic coating provided in this embodiment is a typical fluorinated copolymer.

[0041] Example 3

[0042] This example uses the preparation method of the fluorinated copolymer powder-based super hydrophobic and oleophobic coating in Example 1 to prepare 36 fluorinated copolymer powder-based super hydrophobic and oleophobic coatings, and the 36 fluorinated copolymer powder-based super hydrophobic and oleophobic coatings are respectively recorded as samples 1 to 36. Among them, the specific parameters in the preparation process of the 36 samples are shown in Table 1.

[0043] Table 1 (Specific parameters during the preparation of samples 1-36)

[0044]

[0045]

[0046]

[0047]

[0048] This embodiment also refers to the prior art Chinese patents CN103923540B, CN109400802A, CN108848281A and CN109504239B to prepare four coatings, which are respectively recorded as sample 37, sample 38, sample 39 and sample 40.

[0049] In this example, the prepared samples 1-40 were characterized by the following properties:

[0050] (1) The coating sample was applied on the concrete surface, and the static water contact angle (WCA) and mineral oil contact angle of the coating were measured using a contact angle meter;

[0051] (2) The coating sample was applied to the concrete surface, and the water absorption rate and mineral oil absorption rate (OCA) of the coating concrete were tested according to the standard JC474-2008 "Mortar and Concrete Waterproofing Agent";

[0052] (3) The coating sample was coated on the concrete surface, and the surface of the fluorinated copolymer powder-based super hydrophobic and oleophobic coating was rubbed 50 times with 1500-grit sandpaper. Then, the water contact angle (WCA) and mineral oil contact angle (OCA) of the coating surface were tested.

[0053] The above corresponding performance characterization results are shown in Table 2.

[0054] Table 2 (Performance Characterization Results of Samples 1-36)

[0055]

[0056]

[0057] As shown in Table 1 and Table 2, combined with the performance characterization test of samples 1-36, the hydrophobicity of the fluorinated copolymer powder-based super-hydrophobic and oleophobic coating of the present invention is greater than 150°, and the oleophobicity is also around 150°, with super-hydrophobic and strong oleophobic properties, which can prevent aqueous or oily substances from adhering to and wetting the coating. The water absorption rate of the fluorinated copolymer powder-based super-hydrophobic and oleophobic coating of the present invention is about 0.01%, and the oil absorption rate is about 0.2%, which is significantly lower than that of samples 37-40 prepared under the prior art, indicating that the fluorinated copolymer powder-based super-hydrophobic and oleophobic coating of the present invention has excellent anti-penetration ability. The hydrophobic and oleophobic properties of the fluorinated copolymer powder-based super-hydrophobic and oleophobic coating of the present invention are still super-hydrophobic and strong oleophobic after 50 frictions with 1500 mesh sandpaper, and have good wear resistance.

[0058] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing fluorinated copolymer powder, characterized in that: The following steps are involved: Step S10, dissolving the fluorine-containing monomer and the non-fluorine-containing monomer in DMF and / or DMAC at a ratio of (2-30) wt %: (2-30) wt %, adding (0.5-3) wt % of azobisisobutyronitrile (AIBN), and polymerizing at a temperature of 50° C.-90° C. for 1-12 hours to obtain a fluorine-containing copolymer solution; Step S20, pouring the fluorinated copolymer solution into water, and obtaining a precipitate through precipitation and filtration; Step S30, repeatedly washing and filtering the precipitate with alcohol to obtain a washed precipitate; Step S40, vacuum drying the washed precipitate, grinding it into powder, and passing it through a 400-mesh sieve to obtain fluorine-containing copolymer powder.

2. The method for preparing the fluorinated copolymer powder according to claim 1, characterized in that: in, In step S10, the fluorine-containing monomer is selected from any one or more of perfluorononylethyl methacrylate, perfluorononylethyl acrylate, perfluorononylethylene, perfluorooctylethyl acrylate, perfluorooctylethyl methacrylate, perfluorooctylethylene, dodecafluoroheptyl methacrylate, dodecafluoroheptyl acrylate, perfluorohexylethyl acrylate, perfluorohexylethyl methacrylate, perfluorohexylethylene, perfluorobutylethyl methacrylate, perfluorobutylethyl acrylate, perfluorobutylethylene, hexafluorobutyl methacrylate, and hexafluorobutyl acrylate.

3. The method for preparing the fluorinated copolymer powder according to any one of claims 1 to 3, characterized in that: in, In step S10, the non-fluorine monomer is selected from any one or more of alkyl acrylates having a carbon chain number of 1-18 and alkyl methacrylates having a carbon chain number of 1-18.

4. The method for preparing the fluorinated copolymer powder according to claim 1, characterized in that: in, In step S30, the alcohol is any one or more of methanol, ethanol, propanol, and isopropanol, and the repeated washing is performed for no less than 3 times.

5. A fluorinated copolymer powder, characterized in that: The fluorinated copolymer powder is prepared by the preparation method of any one of claims 1 to 4.

6. A method for preparing a fluorinated copolymer powder-based super hydrophobic and oleophobic coating, characterized in that: The following steps are involved: S50, applying the adhesive to the surface of the cement-based material by brushing and waiting for it to be semi-dry, which is recorded as semi-dry coating; S60, spraying the fluorinated copolymer powder according to claim 5 onto the semi-dry coating and curing the coating to obtain a fluorinated copolymer powder-based super hydrophobic and oleophobic coating.

7. The method for preparing a fluorinated copolymer powder-based super hydrophobic and oleophobic coating according to claim 6, characterized in that: in, In step S50, the adhesive is 704 organic silicone adhesive, and the semi-dry condition is curing at room temperature for 0.5-1h.

8. The method for preparing a fluorinated copolymer powder-based super hydrophobic and oleophobic coating according to claim 6, characterized in that: in, In step S60, the curing condition is curing at room temperature for 22-25 hours.

9. A fluorinated copolymer powder-based super hydrophobic and oleophobic coating, characterized in that: The super hydrophobic and oleophobic coating is prepared by the method for preparing a fluorinated copolymer powder-based super hydrophobic and oleophobic coating according to any one of claims 6 to 8.

10. The fluorinated copolymer powder-based super hydrophobic and oleophobic coating according to claim 9, characterized in that: in, The fluorinated copolymer powder-based super hydrophobic and oleophobic coating comprises a hydrophobic and oleophobic low surface energy layer and an impermeable dense layer. The low surface layer is sprayed by the fluorinated copolymer powder and has hydrophobic and oleophobic properties, thereby giving the coating anti-fouling and self-cleaning capabilities. The dense layer is composed of organic silica gel and has high density and high strength after curing, giving the coating excellent anti-penetration ability and mechanical wear resistance.

Images