A polymer-modified epoxy resin coating having perfluorinated branched short chains and a method for its preparation

Abstract

The application discloses a polymer modified epoxy resin coating with perfluorinated branched short chains and a preparation method thereof, butyl acrylate, styrene, maleic anhydride, methyl methacrylate with perfluorinated branched short chains or styrene with perfluorinated branched short chains are placed at 40-60 DEG C, a solvent and an initiator are added after sufficient mixing, and a polymer with perfluorinated branched short chains is obtained after heating reaction. A first solution prepared from the polymer is uniformly mixed with a second solution prepared from an epoxy resin and a curing agent; the mixture is sprayed and gradient temperature curing is carried out, and a polymer modified epoxy resin coating with perfluorinated branched short chains is obtained. The coating improves the wetting performance of the coating surface while ensuring the anticorrosion ability of the coating itself, and changes the coating from hydrophilicity to hydrophobicity.

Description

Technical Field

[0001] This invention relates to a polymer with perfluorinated branched short chains and a method for preparing and applying a modified epoxy resin coating thereof, belonging to the field of epoxy resin coating technology. Background Technology

[0002] Epoxy resin is a general term for polymers containing two or more epoxy groups in their molecules, and it currently occupies the largest market share in the coating industry. Epoxy resin coatings possess excellent abrasion resistance, insulation, acid and alkali resistance, and other properties, making them the most widely used resin in the field of metal corrosion protection. However, epoxy resin still has many limitations, such as poor hydrophobicity, poor weather resistance, and decreased adhesion over long-term use. This necessitates modification of epoxy resins to meet performance requirements during application. Therefore, finding suitable modification methods to improve the performance of epoxy resins in these aspects will help them achieve wider application.

[0003] Polymers with perfluorinated branched short chains can form coatings with excellent hydrophobicity on substrate surfaces. Furthermore, as acrylate polymers, these polymers can have some of their properties modified by introducing monomers containing functional groups. Therefore, modifying epoxy resins with perfluorinated branched short-chain polymers can improve the hydrophobicity of epoxy resins to a certain extent, while having minimal impact on properties such as hardness and adhesion. Summary of the Invention

[0004] In order to overcome the shortcomings of poor hydrophobicity in existing epoxy resin coatings, the present invention aims to provide a polymer with perfluorinated branched short chains, a method for preparing the polymer, and a modified epoxy resin coating based on the polymer.

[0005] To solve the above technical problems, the technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a polymer having perfluorinated branched short chains, the polymer being a polymer having the following general chemical structural formula:

[0007]

[0008] Wherein, R is hydrogen or methyl, R1 is any group from C1 to C18 alkyl, preferably C4 alkyl, Rf1 is CH2CH2C(CF3)2CF2CF2CF3, and Rf2 is CH2C(CF3)2CF2CF2CF3.

[0009] (a+b):(c+d):e = 1.2:1:1, where a and b are not both 0, and c and d are not both 0.

[0010] In a second aspect, the present invention also provides a method for preparing the polymer with perfluorinated branched short chains described in the first aspect, comprising:

[0011] In a nitrogen atmosphere, acrylate monomers , With styrene monomers , and maleic anhydride monomer After being added to a container, the mixture is heated and stirred to ensure thorough mixing of the monomers. Once fully mixed, the solvent and initiator are added, and the polymerization reaction is carried out under stirring to obtain a polymer with perfluorinated branched short chains.

[0012] Furthermore, acrylate monomers It is selected from any one of methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, isooctyl methacrylate, lauryl methacrylate, octadecyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, isooctyl acrylate, and octadecyl acrylate, with butyl acrylate being preferred.

[0013] Furthermore, acrylate monomers , With styrene monomers , and maleic anhydride monomer The molar ratio of these three types of monomers is 6:5:5.

[0014] Furthermore, the mixture is heated and stirred to ensure thorough mixing of the monomers. The stirring temperature is 40-60°C and the stirring time is 5-20 minutes.

[0015] Furthermore, the initiator is selected from one or more of organic peroxides, inorganic peroxides, and azo compounds, such as benzoyl peroxide (BPO), ammonium persulfate, and azobisisobutyronitrile (AIBN), and the amount added is 0.1% to 1% of the total mass of the monomer.

[0016] Furthermore, the solvent is selected from any one or more of ethyl acetate, propyl acetate, n-butyl acetate, and toluene, and the amount of solvent added is 30% to 60% of the total mass of the monomer.

[0017] Furthermore, the polymerization reaction temperature is 70~90℃, and the reaction time is 3~7h.

[0018] Thirdly, the present invention provides a modified epoxy resin coating comprising a first solution made of a polymer having perfluorinated branched short chains as described in the first aspect, and a second solution made of an epoxy resin and a curing agent.

[0019] Furthermore, the epoxy resin is selected from E-51 type epoxy resins, and the weight ratio of the polymer with perfluorinated branched short chains to the epoxy resin is 1:10.

[0020] Furthermore, the curing agent is selected from either ethylenediamine-type curing agent or polyamide-type curing agent, and its addition amount is 15% to 50% of the epoxy resin mass.

[0021] Furthermore, the polymer with perfluorinated branched short chains is dissolved in ethyl acetate, and methyl nonafluorobutyl ether is added under ultrasonication to prepare a first solution, wherein the mass ratio of ethyl acetate, methyl nonafluorobutyl ether and the polymer with perfluorinated branched short chains is 100:150:1.

[0022] Furthermore, the epoxy resin and curing agent are dissolved in dichloromethane or dichloroethane solvent to prepare a second solution, wherein the mass ratio of solvent to epoxy resin is 20:1.

[0023] Fourthly, the present invention provides a modified epoxy resin coating, which is obtained by spraying and curing the modified epoxy resin coating described in the third aspect onto a substrate.

[0024] Furthermore, after spraying the coating onto the substrate, it is first left at room temperature for 1-2 hours, and then cured at 60℃, 80℃, and 120℃ for 1 hour, 2 hours, and 2 hours respectively.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] (1) Ordinary epoxy resin coatings have certain anti-corrosion capabilities, but their hydrophobicity is poor and they cannot adapt to anti-corrosion conditions in humid environments. The polymer-modified epoxy resin coating with perfluorinated branched short chains provided by this invention, due to the presence of fluorinated groups and their migration to the coating surface, will further reduce the surface free energy of the coating. Therefore, while ensuring the anti-corrosion capability of the coating itself, it can improve the wettability of the coating surface, making it change from hydrophilic to hydrophobic, thus enabling epoxy resin coatings to have a wider range of applications.

[0027] (2) In the polymer with perfluorinated branched short chains, the fluorinated groups have a branched short-chain structure. Studies have shown that the longer the fluorinated chain segment, the stronger its recalcitrant degradation and bioaccumulation, and therefore the stronger its hazard. Currently, the fluorinated groups in common fluoropolymers are long straight-chain fluorinated groups. In comparison, the fluorinated groups in this invention have shorter fluorinated chain segments and excellent environmental performance. Attached Figure Description

[0028] Figure 1 The image shows the water contact angle data of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-5 of this invention.

[0029] Figure 2 The image shows the water contact angle data of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 6-10 of this invention.

[0030] Figure 3 This is a graph showing the oil contact angle data of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-5 of the present invention;

[0031] Figure 4 This is a graph showing the oil contact angle data of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 6-10 of this invention;

[0032] Figure 5 The graph shows the water absorption rate data of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-5 of this invention.

[0033] Figure 6 The graph shows the water absorption rate data of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 6-10 of this invention.

[0034] Figure 7 Fluoro-containing styrene prepared according to the present invention 1 H NMR spectrum;

[0035] Figure 8 Fluoro-containing styrene prepared according to the present invention 19 F NMR spectrum;

[0036] Figure 9 Infrared spectra of the polymers prepared in Comparative Example 1 and Examples 1-5 of this invention;

[0037] Figure 10 Infrared spectra of the polymers prepared in Comparative Example 1 and Examples 6-10 of this invention;

[0038] Figure 11 Water contact angle diagrams of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-5;

[0039] Figure 12 The water contact angle diagrams are for the polymer-modified epoxy resin coatings prepared in Examples 6-10;

[0040] Figure 13 Oil contact angle diagrams of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-5;

[0041] Figure 14 The diagram shows the oil contact angle of the polymer-modified epoxy resin coatings prepared in Examples 6-10. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0044] Among them, fluorinated acrylate monomers This is a self-made fluorinated alcohol synthesized according to patent (publication number CN110540614A). It is prepared by reacting dichloromethane as a solvent with methacryloyl chloride in the presence of a base.

[0045] Fluorinated styrene monomers The synthesis reaction process is as follows:

[0046]

[0047] The synthesis process includes the following steps: 15g of anhydrous potassium fluoride, 1g of tetrabutylammonium bromide, 7.5g of 4-chloromethylstyrene, and 100mL of N,N-dimethylacetamide are added to a sealed tube. Finally, 20g of hexafluoropropylene dimer is added, and the mixture is heated to 80℃ and reacted for 30h. After the reaction is complete, the product is extracted with diethyl ether and washed with water to thoroughly remove water-soluble substances such as N,N-dimethylacetamide and potassium fluoride from the reaction system. The organic phase and aqueous phase are then initially separated using a separatory funnel. Anhydrous sodium sulfate is then added to the separated organic phase and stirred for 30 minutes to remove residual water. The sodium sulfate is removed by filtration, and the resulting filtrate is rotary evaporated at 40℃ to remove diethyl ether, yielding a crude product. Column chromatography is then performed, and the product is eluted with a mixed organic solvent (petroleum ether:ethyl acetate = 200:10) to obtain 8.2g of a colorless solution, thus yielding fluorinated styrene with a yield of 47.4%. 1 H NMR spectrum and 19 The F NMR spectra are as follows: Figure 7 and Figure 8 As shown.

[0048] Comparative Example 1

[0049] The structure of polymer BS-0 is as follows:

[0050]

[0051] a:c:e = 1.2:1:1, where b = 0 and d = 0.

[0052] The synthesis process includes the following steps: Weigh 1.54 g of butyl acrylate, 1.04 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C, and after the maleic anhydride is fully dissolved, add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight monomers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluoropolymer BS-0, whose infrared spectrum is shown below. Figure 9 and Figure 10 As shown.

[0053] Example 1

[0054] The structure of polymer BF-1 is as follows:

[0055]

[0056] a:b:c:e=0.96:0.24:1:1, where d=0.

[0057] The synthesis process includes the following steps: Weigh 1.04 g of fluorinated methacrylate, 1.23 g of butyl acrylate, 1.04 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C until the maleic anhydride is fully dissolved, then add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer BF-1, whose infrared spectrum is shown below. Figure 9 As shown.

[0058] Example 2

[0059] The structure of polymer BF-2 is as follows:

[0060]

[0061] a:b:c:e=0.72:0.48:1:1, where d=0.

[0062] The synthesis process includes the following steps: Weigh 2.07 g of fluorinated methacrylate, 0.92 g of butyl acrylate, 1.04 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C until the maleic anhydride is fully dissolved, then add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer BF-2, whose infrared spectrum is shown below. Figure 9 As shown.

[0063] Example 3

[0064] The structure of polymer BF-3 is as follows:

[0065]

[0066] a:b:c:e=0.48:0.72:1:1, where d=0.

[0067] The synthesis process includes the following steps: Weigh 3.11g of fluorinated methacrylate, 0.92g of butyl acrylate, 1.04g of styrene, and 0.39g of maleic anhydride, add them to a flask, stir at 50℃, and after the maleic anhydride is fully dissolved, add 0.015g of initiator AIBN and 2g of n-butyl acetate, heat to 80℃, and react for 4 hours. After the reaction is complete, add 10mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50℃ oven for 12 hours to remove residual methanol, finally obtaining the fluorinated polymer BF-3, whose infrared spectrum is shown below. Figure 9 As shown.

[0068] Example 4

[0069] The structure of polymer BF-4 is as follows:

[0070]

[0071] a:b:c:e=0.24:0.96:1:1, where d=0.

[0072] The synthesis process includes the following steps: Weigh 4.15g of fluorinated methacrylate, 0.31g of butyl acrylate, 1.04g of styrene, and 0.39g of maleic anhydride, add them to a flask, stir at 50℃, and after the maleic anhydride is fully dissolved, add 0.015g of initiator AIBN and 2g of n-butyl acetate, heat to 80℃, and react for 4 hours. After the reaction is complete, add 10mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50℃ oven for 12 hours to remove residual methanol, finally obtaining the fluorinated polymer BF-4, whose infrared spectrum is shown below. Figure 9 As shown.

[0073] Example 5

[0074] The structure of polymer BF-5 is as follows:

[0075]

[0076] b:c:e=1.2:1:1, where a=0 and d=0.

[0077] The synthesis process includes the following steps: Weigh 5.18 g of fluorinated methacrylate, 1.04 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C, and after the maleic anhydride is fully dissolved, add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer BF-5, whose infrared spectrum is shown below. Figure 9 As shown.

[0078] Example 6

[0079] The structure of polymer SF-1 is as follows:

[0080]

[0081] a:c:d:e=1.2:0.8:0.2:1, where b=0.

[0082] The synthesis process includes the following steps: Weigh 1.54 g of butyl acrylate, 0.87 g of fluorinated styrene, 0.83 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C until the maleic anhydride is fully dissolved, then add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer SF-1, whose infrared spectrum is shown below. Figure 10 As shown.

[0083] Example 7

[0084] The structure of polymer SF-2 is as follows:

[0085]

[0086] a:c:d:e=1.2:0.6:0.4:1, where b=0.

[0087] The synthesis process includes the following steps: Weigh 1.54 g of butyl acrylate, 1.74 g of fluorinated styrene, 0.63 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C until the maleic anhydride is fully dissolved, then add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer SF-2, whose infrared spectrum is shown below. Figure 10 As shown.

[0088] Example 8

[0089] The structure of polymer SF-3 is as follows:

[0090]

[0091] a:c:d:e=1.2:0.4:0.6:1, where b=0.

[0092] The synthesis process includes the following steps: Weigh 1.54 g of butyl acrylate, 2.62 g of fluorinated styrene, 0.42 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C until the maleic anhydride is fully dissolved, then add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer SF-3, whose infrared spectrum is shown below. Figure 10 As shown.

[0093] Example 9

[0094] The structure of polymer SF-4 is as follows:

[0095]

[0096] a:c:d:e=1.2:0.2:0.8:1, where b=0.

[0097] The synthesis process includes the following steps: Weigh 1.54 g of butyl acrylate, 3.49 g of fluorinated styrene, 0.21 g of styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C until the maleic anhydride is fully dissolved, then add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer SF-4, whose infrared spectrum is shown below. Figure 10 As shown.

[0098] Example 10

[0099] The structure of polymer SF-5 is as follows:

[0100]

[0101] a:d:e=1.2:1:1, where b=0 and c=0.

[0102] The synthesis process includes the following steps: Weigh 1.54 g of butyl acrylate, 4.36 g of fluorinated styrene, and 0.39 g of maleic anhydride, add them to a flask, stir at 50 °C, and after the maleic anhydride is fully dissolved, add 0.015 g of initiator AIBN and 2 g of n-butyl acetate, heat to 80 °C, and react for 4 h. After the reaction is complete, add 10 mL of methanol, stir, and recrystallize the polymer in the original solution. Filter, repeat three times to wash away n-butyl acetate, some low molecular weight polymers, and unpolymerized monomers. The obtained solid is dried in a 50 °C oven for 12 h to remove residual methanol, finally obtaining the fluorinated polymer SF-5, whose infrared spectrum is shown below. Figure 10 As shown.

[0103] Preparation of polymer-modified epoxy resin coating:

[0104] 0.2g of epoxy resin (E-51), 0.1g of polyamide curing agent, and 4g of dichloromethane were mixed and ultrasonically treated for 5 minutes to obtain solution A. Then, 0.02g of the BS-0, BF series, or SF series polymers prepared in Examples 1-10 and Comparative Example 1 were weighed and dissolved in 2g of ethyl acetate and ultrasonically treated for 5 minutes. Subsequently, 3g of methyl nonafluorobutyl ether was added, and ultrasonic treatment was repeated for 5 minutes to obtain solution B. Solution A was then placed in an ultrasonic cleaner, and solution B was slowly added over 5 minutes, followed by ultrasonic treatment for 20 minutes to ensure the polymer was fully dispersed in the epoxy resin and curing agent. The resulting mixture was then placed in a 0.5mm nozzle spray gun and, under a pressure of 300 kPa, at a distance of 20 cm from the glass slide, the solution was evenly sprayed onto the cleaned slide. After spraying, the glass slides were left at room temperature for 2 hours to slowly evaporate most of the solvent. Then, the slides were placed in an oven at 60°C for 1 hour, followed by treatment at 80°C for 2 hours, and finally at 120°C for 2 hours to obtain the modified epoxy resin coating. Following the above preparation method, three coated glass slides were prepared for each polymer to obtain HBS-0, HBF series, or HSF series modified epoxy resin coatings.

[0105] Hydrophobic and oleophobic tests were conducted on the polymer-modified epoxy resin coatings prepared in Examples 1-10 and Comparative Example 1.

[0106] The water contact angle of polymer-modified epoxy resin coatings was tested, with each coating tested three times and the average value taken. Test conditions: liquid volume 3 μL, height 0.5 cm, magnification 7x. Results are as follows: Figure 1 and Figure 2 , Figure 11 and Figure 12 As shown.

[0107] The oil contact angle of the modified epoxy resin coatings was then tested separately, with each coating tested three times and the average value taken. Test conditions: liquid volume 3 μL, height 0.5 cm, magnification 7x. Results are as follows: Figure 3 and Figure 4 , Figure 13 and Figure 14 As shown.

[0108] When contact angle is used as an indicator of hydrophobicity, the test results of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-10 show that the water contact angle of the fluorine-free polymer-modified epoxy resin coating HBS-0 is only 83.4°, indicating that this coating is a hydrophilic coating. In contrast, the water contact angles of the HBF and HSF series coatings with added fluorinated copolymers are both greater than 90°, eventually reaching 106.4° and 97.1° respectively with increasing fluorine content. Based on the water contact angle data, the coatings have become hydrophobic with relatively good hydrophobic properties. Meanwhile, the oil contact angle of HBS-0 is 28.2°, while the oil contact angles of the HBF and HSF series coatings with added fluorinated copolymers are significantly greater than 28.2°, eventually reaching 57.2° and 48.2° respectively with increasing fluorine content. This is because the presence of fluorinated monomers makes it easier for the polymer to migrate to the coating interface, increasing the fluorine content on the coating surface and thus reducing the surface free energy of the coating. The HBF series coatings exhibit superior hydrophobic and oleophobic properties compared to the HSF series coatings with the same fluorine content. This is primarily due to the compatibility differences between different fluorinated polymers and epoxy resins. The compatibility between epoxy resins and BF series polymers is worse than that between epoxy resins and SF series polymers. Consequently, the fluorinated groups in the HBF series coatings are more likely to migrate to the coating surface due to their inherent properties, resulting in a lower surface free energy and thus stronger hydrophobic and oleophobic properties.

[0109] Waterproofing tests were conducted on the polymer-modified epoxy resin coatings prepared in Examples 1-10 and Comparative Example 1.

[0110] The water absorption rate of polymer-modified epoxy resin coatings was tested. Each coating was tested three times, and the average value was taken. Test conditions: A 76mm × 26mm glass slide with a modified epoxy resin coating was completely immersed in deionized water for 24 hours. After immersion, the slide was removed, the surface moisture was wiped off with filter paper, and the weight of the glass slide was measured. Let m0 be the initial weight of the glass slide, m1 be the initial weight of the coated glass slide, and m2 be the weight of the coated glass slide after immersion. The water absorption rate (WS) was calculated using the formula: WS(%) = (m2 - m1) / (m1 - m0) × 100%. Results are as follows: Figure 5 and Figure 6 As shown

[0111] When water absorption rate is used as an indicator of waterproofness, the test results of the polymer-modified epoxy resin coatings prepared in Comparative Example 1 and Examples 1-10 show that the water absorption rate of the fluorine-free polymer-modified epoxy resin coating HBS-0 is 2.13%, while the water absorption rates of the HBF series and HSF series coatings with added fluorinated copolymers are both lower than 2.13%, and eventually decrease to 1.75% and 1.85% respectively as the fluorine content increases. This is because the presence of fluorinated monomers makes it easier for the polymer to migrate to the coating interface, increasing the fluorine content on the coating surface and thus reducing the surface free energy of the coating. The water absorption rate of the HBF series coatings is better than that of the HSF series coatings at the same fluorine content, which is consistent with the explanation above for the difference in their hydrophobic and oleophobic abilities.

[0112] The adhesion between the coating and the substrate was tested using the cross-cut test method, referring to GB / T 9286-1998 "Paints and Varnishes - Cross-cut Test". The hardness of the modified epoxy resin coating was tested using a pencil hardness tester under 250g pressure, referring to GB / T 6739-2022 "Paints and Varnishes - Pencil Method for Determination of Film Hardness". The hardness and adhesion of the modified epoxy resin coating are shown in Table 1.

[0113] Table 1 Hardness and Adhesion of HBF and HSF Series Coatings

[0114] hardness Adhesion HBS-0 5H 0 HBF-1 5H 0 HBF-2 5H 0 HBF-3 5H 0 HBF-4 5H 0 HBF-5 5H 0 HSF-1 5H 0 HSF-2 5H 0 HSF-3 5H 0 HSF-4 5H 0 HSF-5 5H 0

[0115] Tests showed that the coating's hardness was 5H without fluorine modification. This hardness remained at 5H regardless of changes in the fluorinated monomer and fluorine content, showing no change due to the presence of fluorinated groups and thus having no significant impact on the mechanical properties of the epoxy resin coating. The adhesion of each coating also remained at a good grade of 0, without changing with the increase of fluorinated groups. This is likely because the amount of polymer added relative to the epoxy resin is relatively small, and it does not significantly affect the internal structure of the modified epoxy resin coating, thus having a minimal impact on the mechanical properties of the epoxy resin. Furthermore, the results of hardness and adhesion tests on the modified epoxy resin coating indicate that the fluorine content in the modified epoxy resin does not significantly affect the coating's hardness or adhesion.

[0116] As can be seen from the above implementation process, this invention prepares a polymer with perfluorinated branched short chains using butyl acrylate, fluorinated methacrylate, styrene, fluorinated styrene, and maleic anhydride as raw materials. The prepared polymer with perfluorinated branched short chains is then used to modify epoxy resin coatings. Results show that the modified epoxy resin coating prepared by this invention exhibits good hydrophobic and oleophobic properties with a relatively small amount of fluorinated polymer added, and the good mechanical properties of the modified epoxy resin coating itself are not reduced by the presence of fluorinated groups. Furthermore, the raw material cost involved in this invention is low, and the amount of fluorinated polymer used is low, achieving a balance between economy and functionality.

[0117] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A polymer having perfluorinated branched short chains, characterized in that, This polymer is a polymer with the following general chemical structural formula: Wherein, R is hydrogen or methyl, R1 is any group from C1 to C18 alkyl, preferably C4 alkyl, Rf1 is CH2CH2C(CF3)2CF2CF2CF3, and Rf2 is CH2C(CF3)2CF2CF2CF3. (a+b):(c+d):e = 1.2:1:1, where a and b are not both 0, and c and d are not both 0.

2. The method for preparing the polymer with perfluorinated branched short chains as described in claim 1, characterized in that, include: In a nitrogen atmosphere, acrylate monomers , With styrene monomers , and maleic anhydride monomer After being added to a container, the mixture is heated and stirred to ensure thorough mixing of the monomers. Once fully mixed, the solvent and initiator are added, and the polymerization reaction is carried out under stirring to obtain a polymer with perfluorinated branched short chains.

3. The method as described in claim 2, characterized in that, acrylate monomers , With styrene monomers , and maleic anhydride monomer The molar ratio of the three is 6:5:

5.

4. The method as described in claim 2, characterized in that, Heat and stir to ensure thorough mixing of the monomers. The stirring temperature is 40-60℃ and the stirring time is 5-20 minutes.

5. The method as described in claim 2, characterized in that, The initiator is selected from one or more of organic peroxides, inorganic peroxides, and azo compounds, and its addition amount is 0.1% to 1% of the total mass of the monomer.

6. The method as described in claim 2, characterized in that, The solvent is selected from any one or more of ethyl acetate, propyl acetate, n-butyl acetate, and toluene.

7. The method as described in claim 2, characterized in that, The polymerization reaction temperature is 70~90℃, and the reaction time is 3~7h.

8. A modified epoxy resin coating, characterized in that, It includes a first solution made of a polymer having perfluorinated branched short chains as described in claim 1, and a second solution made of an epoxy resin and a curing agent.

9. The modified epoxy resin coating as described in claim 8, characterized in that, The epoxy resin is selected from E-51 type epoxy resins, and the mass ratio of the polymer with perfluorinated branched short chains to the epoxy resin is 1:

10.

10. A modified epoxy resin coating, characterized in that, It is prepared by spraying and curing the modified epoxy resin coating as described in claim 8 onto a substrate.

Images