Fluorine-containing modified epoxy resin, recoverable organic fluorine modified epoxy resin anticorrosive coating containing dynamic imine bonds, and preparation method and application thereof

Abstract

The invention discloses fluorine-containing modified epoxy resin which is prepared by the following steps: S1, dissolving a carboxyl-containing sulfhydryl compound in an organic solvent, then adding a fluorine-containing alkyl acrylate compound and a photoinitiator, reacting for 4-6 hours under the irradiation of 365 nm ultraviolet light, and then purifying to obtain a fluorine-containing modifier; s2, mixing the fluorine-containing modifier, epoxy resin, a catalyst and a polymerization inhibitor, then heating to 110-120 DEG C, and reacting for 3-7 hours until the acid value is lower than 15 mg KOH / g, so as to obtain the fluorine-containing modified epoxy resin. Fluorine-containing modified epoxy resin and dynamic imine bonds are synergistically introduced to prepare the coating, a hydrophobic barrier is formed through the surface enrichment effect of fluoroalkyl chains, the barrier capacity of the coating to corrosive media is improved, and the material is endowed with a hot-pressing recovery function by means of the reversible exchange reaction of the imine bonds, so that the coating has a good application prospect. The defects that a traditional epoxy resin coating is unrecyclable and insufficient in corrosion resistance and durability are remarkably overcome, and the problem that microcracks and holes are prone to being generated in the curing process of epoxy resin is solved.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to fluorine-modified epoxy resin, recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds, and their preparation methods and applications. Background Technology

[0002] Metals and their alloys, as important components of modern materials, have wide applications in many fields such as national defense, chemical production, transportation, machinery manufacturing, and daily life. However, metallic materials are often exposed to corrosive media (such as Cl). - In environments containing corrosive substances such as hydrogen, oxygen, and oxygen, various forms of corrosion can easily occur. This not only shortens the service life of equipment but may also lead to safety accidents and resource waste. Introducing a polymer coating onto the surface of metal materials can isolate the metal substrate from corrosive media, which is an effective method to prevent metal corrosion.

[0003] While traditional epoxy resin-based anti-corrosion coatings can form a physical barrier against corrosive media, the three-dimensional cross-linked network formed after curing is irreversible, making the coatings difficult to recycle and causing environmental pollution after disposal. Furthermore, traditional coatings are prone to developing micropores and microcracks during curing due to exothermic effects or solvent evaporation, providing channels for corrosive media penetration and reducing long-term anti-corrosion effectiveness. In addition, improving the hydrophobicity of the coating can enhance its anti-corrosion performance, but current research often uses modifiers containing long-chain perfluoroalkyl compounds. These substances pose potential risks to the ecological environment due to their bioaccumulation and environmental persistence, and their application is subject to increasingly stringent environmental regulations. Therefore, there is a need to develop an environmentally friendly and recyclable anti-corrosion material. Summary of the Invention

[0004] The purpose of this invention is to provide a fluorine-modified epoxy resin and a recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds, so as to solve the technical problem that anti-corrosion coatings in the prior art are difficult to recycle.

[0005] According to a first aspect of the present invention, a fluorinated modified epoxy resin is provided, which is prepared by the following steps: S1. Dissolve a carboxyl-containing mercapto compound in an organic solvent, then add a fluorinated alkyl acrylate compound and a photoinitiator, stir evenly, and react under 365 nm ultraviolet light for 4-6 h. After the reaction is completed, first evaporate by rotary evaporation, then dry under vacuum to obtain a fluorinated modifier. S2. Mix the fluorinated modifier, epoxy resin, catalyst and polymerization inhibitor in a specific molar ratio, react at 110~120℃ for 3~7 h, monitor the acid value of the system in real time, and obtain the fluorinated modified epoxy resin when the acid value is lower than 15 mg KOH / g.

[0006] This invention uses short-chain fluorocarbon compounds to replace long-chain perfluoroalkyl compounds, reducing environmental risks while maintaining low surface energy and hydrophobic properties. A fluorinated modifier is obtained by reacting hexafluorobutyl methacrylate with mercaptosuccinic acid in the presence of a photoinitiator to undergo a mercapto-olefin click reaction. Then, the fluorinated modifier is grafted onto epoxy resin in the presence of a catalyst and a polymerization inhibitor through a ring-opening reaction of carboxyl and epoxy groups to obtain a fluorinated modified epoxy resin.

[0007] In some embodiments, the photoinitiator may be PI-1173. The amount of photoinitiator may be 1.5% to 2.5% of the total mass of the fluorinated alkyl acrylate compound and the carboxyl-containing mercapto compound.

[0008] In some embodiments, by weight, the fluorinated modifier is 1-5 parts, the epoxy resin is 90-95 parts, the catalyst is 0.5-0.8 parts, and the polymerization inhibitor is 0.1-0.5 parts.

[0009] In some embodiments, the fluorinated alkyl acrylate compound can be hexafluorobutyl methacrylate, and the carboxyl-containing thiol compound can be mercaptosuccinic acid. The mass ratio of the fluorinated alkyl acrylate compound to the carboxyl-containing thiol compound can be (1.5~1.8):1.

[0010] In some embodiments, in step S1, the structural formula of the fluorine-containing modifier is: .

[0011] In some embodiments, the molar ratio of the fluorinated modifier to the epoxy resin is (0.01~0.03):1.

[0012] In some embodiments, the epoxy resin may be selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin with an epoxy equivalent of 230-340 g / mol.

[0013] In some embodiments, the catalyst may be selected from at least one of 2,4,6-tris(dimethylaminomethyl)phenol, benzyl dimethylamine, tetrabutylammonium bromide, triethylbenzylammonium chloride, and N-hydroxyphenyl dimethylurea.

[0014] In some embodiments, the polymerization inhibitor may be selected from at least one of hydroquinone, p-tert-butylcatechol, catechol, 2,2-diphenyl-1-picrylhydrazine radical, p-hydroxyanisole, and cuprous chloride.

[0015] In some embodiments, in step S1, a crude product is first obtained by rotary evaporation at 45-55°C, and then vacuum dried at 55-65°C. The purpose of rotary evaporation is to remove organic solvents and unreacted low-boiling-point byproducts.

[0016] According to a second aspect of the present invention, a recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds is provided, wherein the raw materials, by weight, include: 8 to 10 parts of a curing agent containing dynamic imine bonds, 35 to 55 parts of the above-mentioned fluorine-modified epoxy resin, and 0.1 to 0.7 parts of a curing accelerator. The structural formula of the curing agent containing dynamic imine bonds is: .

[0017] In some embodiments, the curing agent containing dynamic imine bonds is prepared by the following steps: The phenolic hydroxy aromatic aldehyde compound is reacted with an alicyclic diamine compound at 50-70°C for 4-6 h to obtain the product.

[0018] Specifically, phenolic hydroxy aromatic aldehydes are dissolved in an organic solvent to obtain an organic solvent containing phenolic hydroxy aromatic aldehydes, and alicyclic diamines are dissolved in an organic solvent to obtain an organic solvent containing alicyclic diamines. Then, the organic solvent containing alicyclic diamines is added to the organic solvent containing phenolic hydroxy aromatic aldehydes to carry out an aldehyde-amino condensation reaction.

[0019] In some implementations, the organic solvent may be anhydrous ethanol.

[0020] In some embodiments, after the aldehyde-amino condensation reaction is completed, the organic solvent is removed by rotary evaporation at 50°C to obtain a crude product, which is then purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1) to obtain a curing agent containing dynamic imine bonds.

[0021] In some embodiments, the phenolic hydroxy aromatic aldehyde compound can be vanillin, and the alicyclic diamine compound can be 4,4'-diaminodicyclohexylmethane.

[0022] In some implementations, the reaction is carried out at a temperature of 60°C.

[0023] In some embodiments, the mass ratio of phenolic hydroxy aromatic aldehydes to alicyclic diamines is 1:(1.6~1.8).

[0024] According to a third aspect of the present invention, a method for preparing a recyclable organic fluorine-modified epoxy resin anticorrosive coating containing dynamic imine bonds is provided, comprising the following steps: mixing a curing agent containing dynamic imine bonds, a fluorine-modified epoxy resin, and a curing accelerator, and then curing them sequentially at 85~95℃, 135~145℃, and 155~165℃ for 1~3 h respectively, to obtain the coating. Preferably, curing is performed sequentially at 90℃, 140℃, and 160℃. The curing of single epoxy resin coatings often results in rapid solvent evaporation and concentrated exothermic reaction due to "one-time high-temperature curing," easily forming a large number of bubbles (pores). A stepped curing process first slowly removes residual solvent (such as anhydrous ethanol in the preparation process) from the coating at a low temperature (90℃) stage to avoid rapid solvent evaporation and bubble formation; the medium temperature (140℃) stage promotes stable crosslinking reaction and reduces structural inhomogeneity caused by excessively rapid local reactions; the high temperature (160℃) stage completes the final crosslinking, ensuring network density.

[0025] The present invention comprises a curing agent containing dynamic imine bonds and a fluorinated modified epoxy resin. Under the action of a curing accelerator, through the ring-opening reaction of epoxy groups and amino groups and the dynamic cross-linking of imine bonds, a recyclable organic fluorine modified epoxy resin anti-corrosion coating containing dynamic imine bonds is formed, which has both hydrophobic properties and recyclability. The dynamic imine bonds of the coating can undergo an exchange reaction under thermal stimulation, realizing the topological rearrangement and closed-loop recycling of the coating.

[0026] According to a fourth aspect of the invention, the application of recyclable organic fluorine-modified epoxy resin anticorrosive coatings containing dynamic imine bonds is provided in the preparation of surface anticorrosive coatings for marine engineering facilities, wind turbine towers, oil storage tanks, bridge steel structures, automobiles, and ship metals.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The fluorinated modified epoxy resin of the present invention uses short fluorocarbon chain compounds to replace long-chain perfluoroalkyl compounds, which reduces environmental risks while maintaining low surface energy hydrophobic properties. At the same time, the introduction of fluorine modifier can moderately reduce the crosslinking density of epoxy resin, alleviate the internal stress accumulation caused by excessive crosslinking during the curing process, and thus reduce the generation of microcracks.

[0028] (2) The present invention realizes the closed-loop recycling of thermosetting epoxy resin through a reversible cross-linking network constructed by dynamic imine bonds, thereby reducing the environmental pollution caused by waste coatings.

[0029] (3) The recyclable organic fluorine modified epoxy resin anti-corrosion coating containing dynamic imine bonds of the present invention introduces short fluorocarbon chains and dynamic imine bonds into the epoxy resin system in a synergistic manner. Both organic fluorine and dynamic imine bonds are combined with the epoxy resin matrix through chemical bonding, which effectively improves the compatibility between fluorine components and resin and reduces the adverse effects of micropores generated by phase separation on the mechanical properties and anti-corrosion effect of the coating.

[0030] (4) The coating of the present invention not only forms a hydrophobic barrier through the surface enrichment effect of fluoroalkyl chains, enhancing the coating's ability to block corrosive media, but also endows the material with hot-pressing recycling function through the reversible exchange reaction of imine bonds. This significantly improves the defects of traditional epoxy resin coatings, such as non-recyclability and insufficient corrosion resistance and durability, and also compensates for the problem of microcracks and pores easily generated during the curing process of single epoxy resin coatings. The anti-corrosion coating has excellent mechanical properties, chemical resistance, hydrophobic properties, recyclability, and anti-corrosion properties, and can be used as a surface anti-corrosion coating. Attached Figure Description

[0031] Figure 1 The reaction route diagram for fluorinated modified epoxy resin; Figure 2 This is a reaction route diagram for a curing agent containing dynamic imine bonds; Figure 3 (a) is the Fourier transform infrared spectrum of HFBMA and HFSA of the present invention. Figure 3 (b) shows the Fourier transform infrared spectra of E-51 and FSER. Figure 3 (c) shows the Fourier transform infrared spectra of VAN and VPA. Figure 3 (d) are the Fourier transform infrared spectra of the FSEV of Example 1 and the EV of Comparative Example 1. Figure 4 The graph shows the mechanical performance test results of the FSEV of Examples 1-5 and the EV of Comparative Example 1 of the present invention. Figure 5 These are water contact angle test diagrams of the FSEVs in Examples 1-5 and the EV in Comparative Example 1 of the present invention; Figure 6 The graph shows the hot-pressing recovery test results of the FSEV in Embodiment 2 of the present invention; Figure 7 The graph shows the electrochemical performance test results of the EV in Comparative Example 1 of this invention. Figure 8 This is a graph showing the electrochemical performance test results of the FSEV in Example 1 of the present invention; Figure 9 This is a graph showing the electrochemical performance test results of the FSEV in Example 2 of the present invention; Figure 10 The graph shows the electrochemical performance test results of the FSEV in Example 3 of this invention. Figure 11 The graph shows the electrochemical performance test results of the FSEV in Example 4 of this invention. Figure 12 This is a graph showing the electrochemical performance test results of the FSEV in Example 5 of the present invention. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto. The raw materials and reagents involved in the following embodiments are all commercially available.

[0033] The synthetic route of the fluorinated modified epoxy resin (FSER) of the present invention is as follows: Figure 1 As shown, hexafluorobutyl methacrylate (HFBMA) and mercaptosuccinic acid (MSA) are first reacted via a mercapto-olefin photoclick reaction to obtain a fluorinated modifier (HFSA). Then, under the action of a catalyst, the epoxy groups of epoxy resin (ER) undergo a ring-opening reaction with the carboxyl groups of HFSA to obtain FSER.

[0034] The synthetic route of the dynamic imine bond-containing curing agent (VPA) of the present invention is as follows: Figure 2 As shown, VPA is prepared by an aldehyde-amino condensation reaction of vanillin (VAN) with 4,4'-diaminodicyclohexylmethane (PACM).

[0035] Example 1 This embodiment provides a method for preparing a recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds, comprising the following steps: (1) Synthesis of fluorine-containing modifier (HFSA): 12.02 g of mercaptosuccinic acid was dissolved in 30 mL of anhydrous ethanol and magnetically stirred until completely dissolved. Then, 20.12 g of hexafluorobutyl methacrylate and 0.66 g of photoinitiator PI-1173 were added sequentially, and the mixture was stirred for 30 minutes to make the mixture homogeneous. The above mixed solution was transferred to a 50 mL quartz reaction tube, sealed, and placed in a photochemical reactor. The reaction was carried out at room temperature under 365 nm ultraviolet light for 5 hours. After the reaction was completed, the product was transferred to a rotary evaporator and the organic solvent and unreacted low-boiling-point byproducts were removed by rotary evaporation under vacuum at 50 °C. The crude product was then placed in a vacuum drying oven and dried under vacuum at 60 °C for 2 hours to obtain a colorless viscous liquid, which is HFSA.

[0036] (2) Synthesis of fluorinated modified epoxy resin (FSER): 0.62 g HFSA, 33.83 g bisphenol A type epoxy resin E-51 (molecular weight 392 g / mol), 0.1715 g triethylbenzylammonium chloride and 0.1348 g hydroquinone were added to a 250 mL three-necked round-bottom flask, where n(HFSA):n(E-51) = 0.01:1. The three-necked flask was placed in an oil bath at 110℃ and reacted for 4 hours. The acid value of the system was monitored in real time until it was lower than 15 mg KOH / g, at which point FSER was obtained.

[0037] (3) Synthesis of a dynamic imine bond-containing curing agent (VPA): Under a nitrogen protective atmosphere, 25.24 g of 4,4'-diaminodicyclohexylmethane was added to a 250 mL three-necked flask, followed by 50 mL of anhydrous ethanol. The mixture was stirred continuously until completely dissolved, forming a homogeneous and transparent solution. 15.22 g of vanillin was dissolved in 100 mL of anhydrous ethanol to prepare a homogeneous solution, which was then transferred to a constant-pressure dropping funnel. The solution in the constant-pressure funnel was slowly added to the three-necked flask. After the addition was complete, the reaction system was placed in a 60℃ constant-temperature oil bath and reacted for 4 hours under constant-temperature conditions. After the reaction was completed, the solvent was removed by a rotary evaporator under vacuum at 50℃. The crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1). The target component was collected and placed in a vacuum drying oven and dried at 60℃ for 2 hours to obtain a reddish-brown powdery solid, which is VPA.

[0038] (4) Synthesis of recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds: 38.88 g FSER, 9.03 g VPA and 0.13 g DMP-30 were added sequentially to a 50 mL polytetrafluoroethylene beaker. The beaker was placed in a constant temperature magnetic stirrer, and the temperature was set to 75℃ and the stirring speed to 250 rpm. The mixture was stirred for 15 minutes until a homogeneous and transparent mixture was formed. The mixture was slowly poured into a polytetrafluoroethylene mold with a silane-treated inner wall. The air bubbles were removed under vacuum. A step-curing process was used, and the mold was placed in a high-temperature oven and cured sequentially at 90℃, 140℃ and 160℃ for 2 hours. After naturally cooling to room temperature, the mold was demolded to obtain FSEV.

[0039] Upon observation of the prepared FSEV, it was found that the coating surface was free of micropores and microcracks.

[0040] Example 2 This embodiment provides a method for preparing a recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds, comprising the following steps: (1) Synthesis of fluorine-containing modifier (HFSA): 12.02 g of mercaptosuccinic acid was dissolved in 30 mL of anhydrous ethanol and magnetically stirred until completely dissolved. Then, 20.12 g of hexafluorobutyl methacrylate and 0.66 g of photoinitiator PI-1173 were added sequentially, and the mixture was stirred for 30 minutes to make the mixture homogeneous. The above mixed solution was transferred to a 50 mL quartz reaction tube, sealed, and placed in a photochemical reactor. The reaction was carried out at room temperature under 365 nm ultraviolet light for 5 hours. After the reaction was completed, the product was transferred to a rotary evaporator and the organic solvent and unreacted low-boiling-point byproducts were removed by rotary evaporation under vacuum at 50 °C. The crude product was then placed in a vacuum drying oven and dried under vacuum at 60 °C for 2 hours to obtain a colorless viscous liquid, which is HFSA.

[0041] (2) Synthesis of fluorinated modified epoxy resin (FSER): 0.62 g HFSA, 22.55 g bisphenol A type epoxy resin E-51 (molecular weight 392 g / mol), 0.1338 g triethylbenzylammonium chloride and 0.1158 g hydroquinone were added to a 250 mL three-necked round-bottom flask, where n(HFSA):n(E-51) = 0.015:1. The three-necked flask was placed in an oil bath at 110℃ and reacted for 4 hours. The acid value of the system was monitored in real time until it was lower than 15 mg KOH / g, at which point FSER was obtained.

[0042] (3) Synthesis of a dynamic imine bond-containing curing agent (VPA): Under a nitrogen protective atmosphere, 25.24 g of 4,4'-diaminodicyclohexylmethane was added to a 250 mL three-necked flask, followed by 50 mL of anhydrous ethanol. The mixture was stirred continuously until completely dissolved, forming a homogeneous and transparent solution. 15.22 g of vanillin was dissolved in 100 mL of anhydrous ethanol to prepare a homogeneous solution, which was then transferred to a constant-pressure dropping funnel. The solution in the constant-pressure funnel was slowly added to the three-necked flask. After the addition was complete, the reaction system was placed in a 60℃ constant-temperature oil bath and reacted for 4 hours under constant-temperature conditions. After the reaction was completed, the solvent was removed by a rotary evaporator under vacuum at 50℃. The crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1). The target component was collected and placed in a vacuum drying oven and dried at 60℃ for 2 hours to obtain a reddish-brown powdery solid, which is VPA.

[0043] (4) Synthesis of recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds: 42.37 g FSER, 9.03 g VPA and 0.21 g DMP-30 were added sequentially to a 50 mL polytetrafluoroethylene beaker. The beaker was placed in a constant temperature magnetic stirrer, and the temperature was set to 75℃ and the stirring speed to 250 rpm. The mixture was stirred continuously for 15 minutes until a homogeneous and transparent mixture was formed. The mixture was slowly poured into a polytetrafluoroethylene mold with a silane-treated inner wall. The air bubbles were removed under vacuum. A step-curing process was used, and the mold was placed in a high-temperature oven and cured sequentially at 90℃, 140℃ and 160℃ for 2 hours. After naturally cooling to room temperature, the mold was demolded to obtain FSEV.

[0044] Example 3 This embodiment provides a method for preparing a recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds, comprising the following steps: (1) Synthesis of fluorine-containing modifier (HFSA): 12.02 g of mercaptosuccinic acid was dissolved in 30 mL of anhydrous ethanol and magnetically stirred until completely dissolved. Then, 20.12 g of hexafluorobutyl methacrylate and 0.66 g of photoinitiator PI-1173 were added sequentially, and the mixture was stirred for 30 minutes to make the mixture homogeneous. The above mixed solution was transferred to a 50 mL quartz reaction tube, sealed, and placed in a photochemical reactor. The reaction was carried out at room temperature under 365 nm ultraviolet light for 5 hours. After the reaction was completed, the product was transferred to a rotary evaporator and the organic solvent and unreacted low-boiling-point byproducts were removed by rotary evaporation under vacuum at 50 °C. The crude product was then placed in a vacuum drying oven and dried under vacuum at 60 °C for 2 hours to obtain a colorless viscous liquid, which is HFSA.

[0045] (2) Synthesis of fluorinated modified epoxy resin (FSER): 0.62 g HFSA, 16.91 g bisphenol A type epoxy resin E-51 (molecular weight 392 g / mol), 0.1051 g triethylbenzylammonium chloride and 0.0876 g hydroquinone were added to a 250 mL three-necked round-bottom flask, where n(HFSA):n(E-51) = 0.02:1. The three-necked flask was placed in an oil bath at 110℃ and reacted for 4 hours. The acid value of the system was monitored in real time until it was lower than 15 mg KOH / g, at which point FSER was obtained.

[0046] (3) Synthesis of a dynamic imine bond-containing curing agent (VPA): Under a nitrogen protective atmosphere, 25.24 g of 4,4'-diaminodicyclohexylmethane was added to a 250 mL three-necked flask, followed by 50 mL of anhydrous ethanol. The mixture was stirred continuously until completely dissolved, forming a homogeneous and transparent solution. 15.22 g of vanillin was dissolved in 100 mL of anhydrous ethanol to prepare a homogeneous solution, which was then transferred to a constant-pressure dropping funnel. The solution in the constant-pressure funnel was slowly added to the three-necked flask. After the addition was complete, the reaction system was placed in a 60℃ constant-temperature oil bath and reacted for 4 hours under constant-temperature conditions. After the reaction was completed, the solvent was removed by a rotary evaporator under vacuum at 50℃. The crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1). The target component was collected and placed in a vacuum drying oven and dried at 60℃ for 2 hours to obtain a reddish-brown powdery solid, which is VPA.

[0047] (4) Synthesis of recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds: 45.87 g FSER, 9.03 g VPA and 0.34 g DMP-30 were added sequentially to a 50 mL polytetrafluoroethylene beaker. The beaker was placed in a constant temperature magnetic stirrer, and the temperature was set to 75℃ and the stirring speed to 250 rpm. The mixture was stirred continuously for 15 minutes until a homogeneous and transparent mixture was formed. The mixture was slowly poured into a polytetrafluoroethylene mold with a silane-treated inner wall. The air bubbles were removed under vacuum. A step-curing process was used, and the mold was placed in a high-temperature oven and cured sequentially at 90℃, 140℃ and 160℃ for 2 hours. After naturally cooling to room temperature, the mold was demolded to obtain FSEV.

[0048] Example 4 This embodiment provides a method for preparing a recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds, comprising the following steps: (1) Synthesis of fluorine-containing modifier (HFSA): 12.02 g of mercaptosuccinic acid was dissolved in 30 mL of anhydrous ethanol and magnetically stirred until completely dissolved. Then, 20.12 g of hexafluorobutyl methacrylate and 0.66 g of photoinitiator PI-1173 were added sequentially, and the mixture was stirred for 30 minutes to make the mixture homogeneous. The above mixed solution was transferred to a 50 mL quartz reaction tube, sealed, and placed in a photochemical reactor. The reaction was carried out at room temperature under 365 nm ultraviolet light for 5 hours. After the reaction was completed, the product was transferred to a rotary evaporator and the organic solvent and unreacted low-boiling-point byproducts were removed by rotary evaporation under vacuum at 50 °C. The crude product was then placed in a vacuum drying oven and dried under vacuum at 60 °C for 2 hours to obtain a colorless viscous liquid, which is HFSA.

[0049] (2) Synthesis of fluorinated modified epoxy resin (FSER): 0.62 g HFSA, 13.53 g bisphenol A type epoxy resin E-51 (molecular weight 392 g / mol), 0.0848 g triethylbenzylammonium chloride and 0.0707 g hydroquinone were added to a 250 mL three-necked round-bottom flask, where n(HFSA):n(E-51) = 0.025:1. The three-necked flask was placed in an oil bath at 110℃ and reacted for 4 hours. The acid value of the system was monitored in real time until it was lower than 15 mg KOH / g, at which point FSER was obtained.

[0050] (3) Synthesis of a dynamic imine bond-containing curing agent (VPA): Under a nitrogen protective atmosphere, 25.24 g of 4,4'-diaminodicyclohexylmethane was added to a 250 mL three-necked flask, followed by 50 mL of anhydrous ethanol. The mixture was stirred continuously until completely dissolved, forming a homogeneous and transparent solution. 15.22 g of vanillin was dissolved in 100 mL of anhydrous ethanol to prepare a homogeneous solution, which was then transferred to a constant-pressure dropping funnel. The solution in the constant-pressure funnel was slowly added to the three-necked flask. After the addition was complete, the reaction system was placed in a 60℃ constant-temperature oil bath and reacted for 4 hours under constant-temperature conditions. After the reaction was completed, the solvent was removed by a rotary evaporator under vacuum at 50℃. The crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1). The target component was collected and placed in a vacuum drying oven and dried at 60℃ for 2 hours to obtain a reddish-brown powdery solid, which is VPA.

[0051] (4) Synthesis of recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds: 48.61 g FSER, 9.03 g VPA and 0.48 g DMP-30 were added sequentially to a 50 mL polytetrafluoroethylene beaker. The beaker was placed in a constant temperature magnetic stirrer, and the temperature was set to 75℃ and the stirring speed to 250 rpm. The mixture was stirred continuously for 15 minutes until a homogeneous and transparent mixture was formed. The mixture was slowly poured into a polytetrafluoroethylene mold with a silane-treated inner wall. The air bubbles were removed under vacuum. A step-curing process was used, and the mold was placed in a high-temperature oven and cured sequentially at 90℃, 140℃ and 160℃ for 2 hours. After naturally cooling to room temperature, the mold was demolded to obtain FSEV.

[0052] Example 5 This embodiment provides a method for preparing a recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds, comprising the following steps: (1) Synthesis of fluorine-containing modifier (HFSA): 12.02 g of mercaptosuccinic acid was dissolved in 30 mL of anhydrous ethanol and magnetically stirred until completely dissolved. Then, 20.12 g of hexafluorobutyl methacrylate and 0.66 g of photoinitiator PI-1173 were added sequentially, and the mixture was stirred for 30 minutes to make the mixture homogeneous. The above mixed solution was transferred to a 50 mL quartz reaction tube, sealed, and placed in a photochemical reactor. The reaction was carried out at room temperature under 365 nm ultraviolet light for 5 hours. After the reaction was completed, the product was transferred to a rotary evaporator and the organic solvent and unreacted low-boiling-point byproducts were removed by rotary evaporation under vacuum at 50 °C. The crude product was then placed in a vacuum drying oven and dried under vacuum at 60 °C for 2 hours to obtain a colorless viscous liquid, which is HFSA.

[0053] (2) Synthesis of fluorinated modified epoxy resin (FSER): 0.62 g HFSA, 11.27 g bisphenol A type epoxy resin E-51 (molecular weight 392 g / mol), 0.0713 g triethylbenzylammonium chloride and 0.0594 g hydroquinone were added to a 250 mL three-necked round-bottom flask, where n(HFSA):n(E-51) = 0.03:1. The three-necked flask was placed in an oil bath at 110℃ and reacted for 4 hours. The acid value of the system was monitored in real time until it was lower than 15 mg KOH / g, at which point FSER was obtained.

[0054] (3) Synthesis of a dynamic imine bond-containing curing agent (VPA): Under a nitrogen protective atmosphere, 25.24 g of 4,4'-diaminodicyclohexylmethane was added to a 250 mL three-necked flask, followed by 50 mL of anhydrous ethanol. The mixture was stirred continuously until completely dissolved, forming a homogeneous and transparent solution. 15.22 g of vanillin was dissolved in 100 mL of anhydrous ethanol to prepare a homogeneous solution, which was then transferred to a constant-pressure dropping funnel. The solution in the constant-pressure funnel was slowly added to the three-necked flask. After the addition was complete, the reaction system was placed in a 60℃ constant-temperature oil bath and reacted for 4 hours under constant-temperature conditions. After the reaction was completed, the solvent was removed by a rotary evaporator under vacuum at 50℃. The crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1). The target component was collected and placed in a vacuum drying oven and dried at 60℃ for 2 hours to obtain a reddish-brown powdery solid, which is VPA.

[0055] (4) Synthesis of recyclable organofluorine modified epoxy resin anti-corrosion coating (FSEV) containing dynamic imine bonds: 51.37 g FSER, 9.03 g VPA and 0.63 g DMP-30 were added sequentially to a 50 mL polytetrafluoroethylene beaker. The beaker was placed in a constant temperature magnetic stirrer, and the temperature was set to 75℃ and the stirring speed to 250 rpm. The mixture was stirred continuously for 15 minutes until a homogeneous and transparent mixture was formed. The mixture was slowly poured into a polytetrafluoroethylene mold with a silane-treated inner wall. The air bubbles were removed under vacuum. A step-curing process was used, and the mold was placed in a high-temperature oven and cured sequentially at 90℃, 140℃ and 160℃ for 2 hours. After naturally cooling to room temperature, the mold was demolded to obtain FSEV.

[0056] Comparative Example 1 This comparative example provides a method for preparing an epoxy resin coating (EV) containing dynamic imine bonds, comprising the following steps: (1) Synthesis of a dynamic imine bond-containing curing agent (VPA): Under a nitrogen atmosphere, 25.24 g of 4,4'-diaminodicyclohexylmethane was added to a 250 mL three-necked flask, followed by 50 mL of anhydrous ethanol. The mixture was stirred continuously until completely dissolved, forming a homogeneous and transparent solution. 15.22 g of vanillin was dissolved in 100 mL of anhydrous ethanol to prepare a homogeneous solution, which was then transferred to a constant-pressure dropping funnel. The solution in the constant-pressure funnel was slowly added to the three-necked flask. After the addition was complete, the reaction system was placed in a 60°C constant-temperature oil bath and reacted for 4 hours under constant-temperature conditions. After the reaction was completed, the solvent was removed by a rotary evaporator under vacuum at 50°C. The crude product was purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate = 3:1). The target component was collected and placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain a reddish-brown powdery solid, which was VPA.

[0057] (2) Synthesis of epoxy resin coating containing dynamic imine bonds: 30.44 g E-51, 9.03 g VPA and 0.09 g DMP-30 were added sequentially to a 50 mL polytetrafluoroethylene beaker. The beaker was placed in a constant temperature magnetic stirrer, and the temperature was set to 75℃ and the stirring speed to 250 rpm. The mixture was stirred continuously for 15 minutes until a homogeneous and transparent mixture was formed. The mixture was slowly poured into a polytetrafluoroethylene mold with a silane-treated inner wall. The air bubbles were removed under vacuum. A step-curing process was used, and the mold was placed in a high-temperature oven and cured sequentially at 90℃, 140℃ and 160℃ for 2 hours. After naturally cooling to room temperature, the mold was demolded to obtain EV.

[0058] Thermo Fisher Scientific Nicolet iS10 Fourier transform infrared spectrometer was used to detect hexafluorobutyl methacrylate (HFBMA), fluorinated modifier (HFSA), epoxy resin E-51 (E-51), fluorinated modified epoxy resin (FSER), vanillin (VAN), dynamic imine bond curing agent (VPA), and EV of Comparative Example 1, respectively. The test results are as follows: Figure 3 As shown.

[0059] The infrared absorption curves of HFBMA and HFSA measured by FT-IR are as follows: Figure 3 As shown in (a), in the HFSA curve, the peak intensity of the ester bond significantly increased and the double bond peak disappeared after the reaction of HFBMA and MSA, indicating that HFBMA and MSA underwent a mercapto-alkene reaction. Furthermore, in the 1250-1150 cm⁻¹ range... -1 The presence of multiple characteristic peaks for fluorine-containing groups in the vicinity is attributed to the characteristic absorptions of -CF2 and -CF3. These results demonstrate the successful synthesis of HFSA.

[0060] The infrared absorption curves of epoxy resin E-51 and FSER are as follows: Figure 3As shown in (b), in the FSER curve, after the ring-opening reaction between HFSA and epoxy resin E-51, the values ​​are 1720-1680 cm⁻¹. -1 The disappearance of the C=O peak in the vicinity of the carboxylic acid indicates that the carboxylic acid group (-COOH) in HFSA has undergone a chemical reaction, possibly transforming into an ester bond (-COO-) or other structures. At 1734 cm⁻¹ -1 The appearance of a new C=O peak for ester bonds further indicates that the carboxylic acid in HFSA reacts completely with the epoxy group in the epoxy resin to form an ester bond through ring opening.

[0061] The infrared absorption curves of VAN and VPA are as follows: Figure 3 As shown in (c), the VAN curve shows a value at 3162 cm. -1 A broad peak appears nearby, which originates from the OH stretching vibration of the phenolic hydroxyl group; additionally, at 1666 cm⁻¹... -1的 The peak is attributed to the C=O stretching vibration of the aldehyde group. After the condensation reaction of VAN and PACM, the peak at 1631 cm⁻¹ on the VPA curve is significant. -1 A new peak appeared at 3434 cm⁻¹, corresponding to C=N stretching vibration. Additionally, at 3434 cm⁻¹... -1 The broad peak at 2920 cm⁻¹ can be attributed to the coupling of the stretching vibrations of OH and NH. -1 and 2852 cm -1 The peaks at these locations are associated with asymmetric and symmetric CH and CH2 stretching vibrations, respectively.

[0062] The infrared absorption curves of FSEV and EV are as follows: Figure 3 As shown in (d), it can be observed at 914 cm. -1 The intensity of the characteristic peak of the nearby epoxy group is significantly reduced, indicating that the curing agent VPA has undergone a ring-opening reaction with the epoxy resin. The epoxy group of the epoxy resin undergoes ring-opening and reacts with the carboxyl group of HFSA to form an ester group, and the peak intensity is significantly reduced at 1640 cm⁻¹. -1 The characteristic absorption peak of the stretching vibration of the imine bond appears nearby.

[0063] The FSEVs prepared in Examples 1-5 and the EVs prepared in Comparative Example 1 were used as samples for relevant performance tests.

[0064] I. Performance Testing Methods 1. Mechanical property testing Tensile tests were performed on the test samples using a UTM5000 universal testing machine. The tensile speed was 5 mm / min, and the gauge length was 50 mm. For accuracy, each sample was measured three times, and the average value was taken.

[0065] 2. Thermal stability performance test Thermal stability of the samples was tested using a Netzsch TG209 F1 Libra thermogravimetric analyzer. The atmosphere was a nitrogen atmosphere with a flow rate of 20 mL / min, a heating rate of 10 K / min, and a temperature range of 35 to 800 °C.

[0066] 3. Dynamic thermomechanical property testing Dynamic thermomechanical properties of the samples were tested using a Netzsch DMA 242 E dynamic thermomechanical analyzer (Germany). A double cantilever support was used, with a temperature range of 35 to 180ºC, a heating rate of 3 K / min, a frequency of 1 Hz, and sample dimensions of 36 mm × 5 mm × 4 mm.

[0067] 4. Water contact angle test The contact angle of deionized water on the surface and back of the samples was measured using a Shanghai Zhongchen JC2000C1 contact angle meter, according to GB / T 30693-2014 standard. Test temperature: 25℃. For accuracy, each sample was measured three times and the average value was taken.

[0068] 5. Hot-pressing recovery test The cured film sample was pulverized into powder using a BaiXin LG-01 pulverizer, sieved through a 200-mesh sieve, and then poured into a 1mm thick stainless steel mold. The sample was then hot-pressed for 30 minutes each at 190℃ and 20MPa, and at 170℃ and 20MPa, respectively, using a KeJin HP-100 hot press.

[0069] 6. Electrochemical performance testing Electrochemical testing was conducted using the CHI-660E electrochemical workstation of the Shanghai Chenhua three-electrode battery system to test the corrosion resistance of the samples. A three-electrode system with an area of ​​2.5 cm² was used. 2 A platinum electrode was used as the auxiliary electrode, and a saturated Ag / AgCl electrode as the reference electrode. The working electrode was coated carbon steel immersed in a 3.5 wt% NaCl solution at room temperature, with the NaCl solution serving as the corrosive medium. At 10... 5 ~10 -2 Electrochemical impedance spectroscopy (EIS) data were recorded at a test frequency range of Hz and a sinusoidal voltage signal amplitude of 10 mV.

[0070] II. Performance Test Results The mechanical performance test results of the FSEVs in Examples 1-5 and the EV in Comparative Example 1 are as follows: Figure 4 As shown in Table 1, the comprehensive mechanical performance test results of the FSEVs of Examples 1-5 and the EV of Comparative Example 1 are presented. Figure 4As shown in Table 1, compared to the EV in Comparative Example 1, the elongation at break of the thermosetting materials was improved after the addition of HFSA modifier. The tensile strength showed a trend of first increasing and then decreasing. This is because a moderate degree of crosslinking can improve tensile strength, while excessive crosslinking density may cause stress concentration, leading to a decrease in strength. In addition, excessive addition of fluorine-containing modifier also affects the tensile strength of thermosetting materials. This may be because the electronegativity of fluorine atoms is relatively high, making it easy to form dipole-dipole interactions, which causes fluorine-containing segments to tend to aggregate, forming local high-density regions, resulting in a decrease in strength.

[0071] Furthermore, after the introduction of fluoroalkyl chains, the crosslinking density of FSEV decreased relative to that of EV, which may be attributed to the steric hindrance formed by the fluoroalkyl chains. Additionally, Examples 2 and 3 exhibited the highest glass transition temperatures, possibly because within the range of fluorinated modifier content, the high bond energy of the CF bonds restricts molecular chain segment movement, thus favoring an increased glass transition temperature. However, as the modifier content increased, the glass transition temperature began to decrease. This may be due to the enhanced steric hindrance effect, which allows for easier movement of molecular chain segments in the loose network, resulting in a decrease in both glass transition temperature and crosslinking density.

[0072] Table 1. Test results of comprehensive mechanical properties of the coating

[0073] The thermal stability test results of the FSEVs in Examples 1-5 and the EV in Comparative Example 1 are shown in Table 2. Compared with Comparative Example 1, the temperatures corresponding to a 10% weight loss in Examples 1, 2, and 3 are not significantly different; however, the temperature of Example 5 at T... 10% The temperature dropped to 361.67℃, 13℃ lower than Comparative Example 1. This may be attributed to the increased content of the fluorinated modifier, which preferentially decomposes during heating, leading to earlier overall weight loss of the material. Additionally, the addition of short fluorocarbon chains may also be due to the promotion of molecular chain movement, reduced friction between chains, and less restriction of thermal motion of molecular chain segments, resulting in earlier overall weight loss and a lower char content.

[0074] Table 2. Test results of thermal stability of coatings

[0075] The water contact angle test results of FSEV in Examples 1-5 and EV in Comparative Example 1 are as follows: Figure 5 As shown. By Figure 5As can be seen, the water contact angle of the surface of Comparative Example 1 is 84.2°. Compared with Comparative Example 1, the water contact angles of FSEVs in Examples 1-5 are significantly improved, with the water contact angle of the surface of Example 3 being 111.6°. However, with the increase of fluorinated modified epoxy resin content and the molar ratio of fluorinated modifier to epoxy resin, the surface water contact angle of Example 4 only reached 112.2°, and no significant improvement in the water contact angle was observed. In addition, water contact angle tests were also performed on the bottom (back) surfaces of EV and FSEV coatings. The results show that for the FSEV coating, the water contact angle value of its bottom surface is significantly lower than that of the surface. However, for the EV coating, there is no significant difference in the water contact angle values ​​between the surface and the bottom surface. This phenomenon is attributed to the fact that during the curing process of fluorocarbon chains, under heating conditions, organic fluorine segments migrate more easily to the coating surface and form aggregates and orderly arrangements, resulting in a large amount of fluorine atoms enriched on the coating surface, while the fluorine atom content on the bottom surface of the coating is relatively low, which macroscopically manifests as an improvement in hydrophobic properties.

[0076] The results of the hot-pressing recovery performance test are as follows: Figure 6 As shown, Figure 6 (a) is a photograph of an actual product using thermal compression recycling. Figure 6 (b) shows the stress-strain curve of the hot-pressed recycled material. Figure 6 (a) shows that FSEV could not be restored to a tablet after hot pressing at 170°C and 20 MPa for 30 minutes, while the tablet after hot pressing at 190°C and 20 MPa was smooth and flat, indicating that FSEV has excellent recyclability under these conditions. The recyclability of FSEV thermosetting material was verified by tensile testing. Taking the FSEV of Example 2 as an example, the mechanical property test results are as follows: Figure 6 As shown in (b), the tensile strength of the recycled material is 61.9 MPa, and the mechanical property retention rate is 85.47%.

[0077] Electrochemical performance test results as follows Figures 7-11 As shown. Among them, Figure 7 (a) is the Bode plot of EV in Scale 1. Figure 7 (b) is the phase diagram of EV in Scale 1; Figure 8 (a) is the Bode plot of the FSEV in Example 1. Figure 8 (b) is the phase diagram of the FSEV in Example 1; Figure 9 (a) is the Bode plot of the FSEV in Example 2. Figure 9 (b) is the phase diagram of the FSEV in Example 2; Figure 10 (a) is the Bode plot of the FSEV in Example 3. Figure 10 (b) is the phase diagram of the FSEV in Example 3; Figure 11 (a) is the Bode plot of the FSEV in Example 4. Figure 11 (b) is the phase diagram of the FSEV in Example 4; Figure 12 (a) is the Bode plot of the FSEV in Example 5. Figure 12 (b) is the phase angle diagram of the FSEV in Example 5.

[0078] During the initial immersion phase, the Bode impedance curves of Comparative Example 1 and Examples 1-5 showed diagonal lines over a wide frequency range, with different coatings exhibiting different |Z| values. 0.01 Hz The values ​​are relatively similar, both close to 10. 11 Ω·cm 2 The above demonstrates good corrosion resistance. And... Figure 7 The test results in (a) show that the coating of Comparative Example 1 exhibits poor protective performance in the initial immersion stage, and after 60 days of immersion, |Z| 0.01 Hz Value from 8.35 × 10 10 Ω·cm 2 It dropped to 9.99×10 8 Ω·cm 2 A clear linear response region is visible in the Bode impedance diagram, indicating that the coating of Comparative Example 1 cannot effectively prevent the intrusion of corrosive media and provide long-term protection for the metal substrate. Analysis of the Bode phase diagram shows that the characteristic frequency of the coating in Comparative Example 1 gradually shifts towards the higher frequency region with increasing immersion time. This phenomenon may be attributed to the continuous decay of the coating's protective effectiveness, suggesting that a corrosion product accumulation layer may have formed on the surface of the metal substrate. In contrast, the coating of the Example 1 exhibits a significantly higher characteristic frequency. b The values ​​were lower than those of EV, and after 100 days of immersion, its |Z| 0.01 Hz Values ​​are generally greater than 10 10 Ω·cm 2 This indicates that the addition of fluorine-containing modifiers effectively enhances the coating's media barrier capability and long-term protective stability.

[0079] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A fluorinated modified epoxy resin, characterized in that, It is prepared through the following steps: S1. Dissolve a carboxyl-containing mercapto compound in an organic solvent, then add a fluorinated alkyl acrylate compound and a photoinitiator to the organic solvent. After stirring evenly, react under 365 nm ultraviolet light for 4-6 h. After the reaction is complete, first evaporate by rotary evaporation, then dry under vacuum to obtain a fluorinated modifier. S2. Mix the fluorinated modifier, epoxy resin, catalyst and polymerization inhibitor, and react at 110~120℃ for 3~7 h until the acid value is lower than 15 mg KOH / g to obtain the fluorinated modified epoxy resin. The carboxyl-containing mercapto compound is mercaptosuccinic acid, and the fluorinated alkyl acrylate compound is hexafluorobutyl methacrylate.

2. The fluorinated modified epoxy resin according to claim 1, characterized in that, By weight, the fluorinated modifier is 1-5 parts, the epoxy resin is 90-95 parts, the catalyst is 0.5-0.8 parts, and the polymerization inhibitor is 0.1-0.5 parts; the molar ratio of the fluorinated modifier to the epoxy resin is (0.01-0.03):

1.

3. The fluorinated modified epoxy resin according to claim 1, characterized in that, The mass ratio of the fluorinated alkyl acrylate compound to the carboxyl-containing mercapto compound is (1.5~1.8):

1.

4. The fluorinated modified epoxy resin according to claim 1 or 3, characterized in that, The amount of photoinitiator used is 1.5% to 2.5% of the total mass of the fluorinated alkyl acrylate compound and the carboxyl-containing mercapto compound.

5. The fluorinated modified epoxy resin according to claim 1, characterized in that, The epoxy resin is selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin with an epoxy equivalent of 230~340 g / mol; the catalyst is selected from at least one of 2,4,6-tris(dimethylaminomethyl)phenol, benzyl dimethylamine, tetrabutylammonium bromide, triethylbenzylammonium chloride, and N-hydroxyphenyl dimethylurea; the polymerization inhibitor may be selected from at least one of hydroquinone, p-tert-butylcatechol, catechol, 2,2-diphenyl-1-picrylhydrazine free radical, p-hydroxyanisole, and cuprous chloride.

6. A recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds, characterized in that, The raw materials, by weight, include: 8-10 parts of a curing agent containing dynamic imine bonds, 35-55 parts of the fluorine-modified epoxy resin according to any one of claims 1-5, and 0.1-0.7 parts of a curing accelerator; The structural formula of the curing agent containing dynamic imine bonds is: 。 7. The recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds according to claim 1, characterized in that, The curing agent containing dynamic imine bonds is prepared through the following steps: The phenolic hydroxy aromatic aldehyde compound is reacted with an alicyclic diamine compound at 50-70℃ for 4-6 h to obtain the product. The phenolic hydroxy aromatic aldehyde compound is vanillin, and the alicyclic diamine compound is 4,4'-diaminodicyclohexylmethane.

8. The recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds according to claim 7, characterized in that, The mass ratio of the phenolic hydroxy aromatic aldehyde compound to the alicyclic diamine compound is 1:(1.6~1.8).

9. The method for preparing the recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds according to any one of claims 6 to 8, characterized in that, The process includes the following steps: mixing a curing agent containing dynamic imine bonds, a fluorinated modified epoxy resin, and a curing accelerator, and then curing them sequentially at 85~95℃, 135~145℃, and 155~165℃ for 1~3 h respectively, to obtain the final product.

10. The application of the recyclable organic fluorine-modified epoxy resin anti-corrosion coating containing dynamic imine bonds as described in any one of claims 6 to 8 in the preparation of surface anti-corrosion coatings for marine engineering facilities, wind turbine towers, oil storage tanks, bridge steel structures, automobiles, and ship metals.

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