Fluorine-free anti-corrosion non-stick coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a fluoride-free anti-corrosion non-stick coating and a preparation method thereof.The fluoride-free anti-corrosion non-stick coating is prepared from, by weight, 40-60 parts of functionalized PEEK resin, 5-15 parts of functionalized PDMS, 0.5-2 parts of a surfactant, 0.1-0.5 part of a defoaming agent, 0.1-0.5 part of a flatting agent, 0.5-2 parts of a dispersing agent, 0.05-0.1 part of an emulsifying agent and 30-40 parts of a solvent. The obtained coating has the advantages of being high in non-stickiness, good in compatibility with a base material and high in heat resistance.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a fluorine-free anti-corrosion non-stick coating and its preparation method. Background Technology

[0002] Non-stick coatings, due to their ability to significantly reduce surface adhesion and simplify cleaning processes, have been widely used in kitchenware, food processing, mold making, and many other fields. For a long time, fluorinated coatings, represented by polytetrafluoroethylene (PTFE), have been the mainstream choice due to their extremely low surface energy. However, their environmental hazards and performance shortcomings have become major obstacles to the industry's development. The perfluorinated and polyfluoroalkyl substances used in the production of fluorinated coatings are known as "permanent chemicals," which are difficult to degrade in the natural environment, easily accumulate in organisms, and release toxic gases such as trifluoroacetic acid and phosgene when decomposed at high temperatures, posing a dual threat to human health and the ecological environment. With increasingly stringent global environmental regulations and a surge in consumer demand for green and safe products, the research and development of fluorine-free alternative technologies has accelerated.

[0003] Patent CN117683412B discloses a fluorine-free self-cleaning coating and its preparation method and application, relating to the field of coating technology. The coating comprises the following raw materials: component A and component B; component A includes the following raw materials: mercapto compound, styrene copolymer, initiator, and amino silicone oil; component B includes the following raw materials: epoxy resin, melamine-formaldehyde resin, and curing agent. The fluorine-free self-cleaning coating of this application is highly transparent, water- and oil-repellent, and possesses high hardness, high wear resistance, and strong adhesion to the substrate, resisting various types of mechanical wear. The coating can be constructed on rigid planes (such as glass substrates) and / or flexible curved surfaces; coatings constructed on flexible curved surfaces exhibit excellent flexibility. Patent CN119977358A discloses a method for preparing a fluorine-free hydrophobic and wear-resistant coating based on organosilane crosslinking, comprising the following steps: Step 1, using organic solvents and an ultraviolet ozone cleaner to efficiently decontaminate and activate the glass substrate; Step 2, mixing polydimethylsiloxane (PDMS) and poly(dimethylsiloxane)... co Methylhydrosiloxane (PMHS) was dissolved in ethyl acetate to prepare a spraying solution; step three: the prepared spraying solution was coated onto a glass substrate using a spray gun, and after curing, PDMS was obtained. PMHS hydrophobic coatings produce hydrophobic and wear-resistant coatings. This coating is not limited to glass surfaces but can also be applied to surfaces such as copper, aluminum, stainless steel, ceramics, and plastics, exhibiting excellent hydrophobic and wear-resistant properties. The coating possesses good mechanical properties, hydrophobicity, adhesion, chemical stability, and corrosion resistance.

[0004] However, existing fluorine-free non-stick coating technologies still have the problem of balancing temperature resistance and non-stick properties. Therefore, there is an urgent need in the market to develop a fluorine-free anti-corrosion non-stick coating with good temperature resistance. Summary of the Invention

[0005] To address the problems existing in the prior art, the purpose of this invention is to obtain a fluorine-free non-stick coating that not only has adhesion to the substrate but also good heat resistance and a long service life.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of this invention provides a fluorine-free anti-corrosion non-stick coating, comprising, by weight, the following raw materials: 40-60 parts of functionalized PEEK resin, 5-15 parts of functionalized PDMS, 0.5-2 parts of surfactant, 0.1-0.5 parts of defoamer, 0.1-0.5 parts of leveling agent, 0.5-2 parts of dispersant, 0.05-0.1 parts of emulsifier, and 30-40 parts of solvent.

[0007] In some embodiments, the method for preparing the functionalized PEEK resin includes the following steps: (1) Add 4,4-difluorobenzophenone, 2,5-dihydroxytoluene, hydroquinone, sodium carbonate, and potassium carbonate to sulfolane and toluene. Under a nitrogen atmosphere, heat to 145-155℃ and react for 1.5-2.5 h. Then heat to 165-175℃ and react for 0.8-1.2 h. Finally heat to 195-205℃ and react for 2.5-3.5 h. After drying and pulverizing, wash and dry to obtain methylPEEK. (2) The methyl PEEK, o-dichlorobenzene and chlorobenzene obtained in step (1) are heated to 115-125℃ and stirred for 30-50 min under a nitrogen atmosphere. Then the temperature is raised to 165-175℃ and irradiated with ultraviolet light. The temperature is then raised to 155-165℃ and liquid bromine is added at the same time. Then the mixture is stirred under ultraviolet light for 1.5-2.5 h and cooled to room temperature. The post-treatment yields brominated PEEK. (3) Add the brominated PEEK and sodium hydride obtained in step (2) to DMF, add a tetrahydrofuran solution of p-hydroxybenzaldehyde at 0-5℃, continue the reaction for 2-3h, then raise the temperature to room temperature and continue the reaction for 2-3h to obtain aldehyde-modified PEEK. (4) Add the aldehyde-modified PEEK and sodium persulfate obtained in step (3) to DMF and then add a DMF solution of 2,3-diaminophenol. React at room temperature for 40-45 min, then heat to 100-120℃ and react for 2.5-3.5 h. After post-treatment, functionalized PEEK resin is obtained.

[0008] Existing non-stick coatings mainly rely on perfluorinated compounds to provide low surface energy for non-stick properties. However, fluorinated coatings are gradually being phased out of the market due to drawbacks such as poor degradation, difficulty in recycling, and the generation of toxic fluorinated gases after incineration. PEEK resin, with its good temperature resistance, corrosion resistance, and mechanical properties, has attracted attention as a potential alternative to fluorinated compounds. However, conventional PEEK resin has a high surface energy and relatively poor non-stick properties. The applicant has attempted to increase the non-stick properties of the coating by introducing PDMS; however, PEEK and PDMS have poor compatibility, leading to phase separation and easy cracking of the coating. This invention introduces aldehyde groups by nucleophilic substitution of brominated PEEK with p-hydroxybenzaldehyde. The aldehyde group further reacts with 2,3-diaminophenol to generate functionalized PEEK with heterocyclic structures and hydroxyl groups on the side chains. This functionalized PEEK can react with functionalized PDMS to form strong chemical bonds between the PEEK and PDMS chains, achieving molecular-level compatibility. This results in a non-stick coating with uniform microstructure and excellent performance, while also enhancing the interaction between PEEK and pigments and substrates, improving coating adhesion and corrosion resistance without affecting the thermal stability of the PEEK backbone. Furthermore, the resulting heterocycle is a rigid planar conjugated structure with highly delocalized electrons, making it very stable and overcoming the problem of easy hydrolysis of chemical bonds formed after conventional functionalized PEEK reacts with other components.

[0009] In some embodiments, the molar ratio of 4,4-difluorobenzophenone, 2,5-dihydroxytoluene, hydroquinone, sodium carbonate, and potassium carbonate is (0.9-1.1):1:(0.8-1.1):(1-1.1):(1-1.1).

[0010] In some embodiments, the mass ratio of methyl PEEK to liquid bromine in step (2) is 1:(0.2-0.3).

[0011] In some embodiments, the mass ratio of PEEK bromide to p-hydroxybenzaldehyde in step (3) is 1:(0.3-0.5).

[0012] In some embodiments, the mass ratio of aldehyde-modified PEEK to 2,3-diaminophenol in step (4) is 1:(0.15-0.25).

[0013] In some embodiments, the functionalized PDMS is a hydroxyl-terminated polydimethylsiloxane or an amino-terminated polydimethylsiloxane.

[0014] In some embodiments, the surfactant is a nonionic surfactant.

[0015] In some embodiments, the defoamer is an organosilicone defoamer.

[0016] A second aspect of this invention provides a method for preparing a fluorine-free anti-corrosion and non-stick coating, comprising the following steps: S1. Functionalized PEEK resin and surfactant are added to part of the solvent to obtain a PEEK dispersion; functionalized PDMS and emulsifier are added to the remaining solvent to obtain a PDMS emulsion; S2. Stir the PEEK dispersion obtained in step S1 with PDMS emulsion, defoamer, leveling agent and dispersant at room temperature for 20-30 minutes to obtain a coating mixture; S3. Apply the coating mixture obtained in step S2 to the surface of the substrate, dry it, and then sinter it to obtain a coating.

[0017] In some embodiments, the drying temperature is 60-120°C, the sintering temperature is 320-380°C, and the time is 3-15 minutes.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a fluorine-free anti-corrosion non-stick coating prepared by functionalized PPEK resin, functionalized PDMS and other additives, which also has the advantages of strong adhesion to the substrate and good heat resistance.

[0019] (2) By preparing functionalized PEEK resin, the present invention enables the PEEK chain and PDMS chain to form a strong chemical bond connection, which solves the problem of poor compatibility between PEEK and PDMS and easy cracking of coating. At the same time, it enhances the interaction between PEEK and pigments and substrates, improves the adhesion and anti-corrosion sealing of coating without affecting the thermal stability of PEEK main chain. In addition, the final heterocycle is a rigid planar conjugated structure with highly delocalized electrons, which is very stable and makes up for the problem of easy hydrolysis of chemical bonds generated after conventional functionalized PEEK reacts with other components. Detailed Implementation

[0020] The present invention will be described below with reference to specific embodiments. It should be noted that the following embodiments are examples of the present invention and are used only to illustrate the invention, not to limit it. Other combinations and various modifications within the scope of the present invention can be made without departing from its spirit or scope.

[0021] In the following examples and comparative examples, the compounds and related reagents used were all commercially available. The surfactant was BASF Pluriol E 1000; the defoamer was BYK-024; the leveling agent was BASF Lutensol XP70; the dispersant was BYK-190; the emulsifier was OP-10; the hydroxyl-terminated polydimethylsiloxane was hydroxyl-terminated polydimethylsiloxane with Mn=2000, purchased from Wuhan Yuancheng Chemical Co., Ltd.; and the PEEK resin was PEEK resin powder with an average particle size of 75 μm, purchased from Hubei Langbowan Biomedical Co., Ltd.

[0022] Unless otherwise specified, the post-processing steps such as "washing", "drying", "filtration", and "rotary evaporation" used below are routine operations for those skilled in the art, and can be selected according to actual operation.

[0023] Preparation Example 1 The preparation method of functionalized PEEK resin-1 includes the following steps: (1) 0.3 mol of 4,4-difluorobenzophenone, 0.3 mol of 2,5-dihydroxytoluene, 0.3 mol of hydroquinone, 0.315 mol of sodium carbonate, and 0.315 mol of potassium carbonate were added to 348 ml of sulfolane and 100 ml of toluene. The mixture was heated to 150 °C for 2 h under a nitrogen atmosphere, then heated to 170 °C for 1 h while distilling off the toluene. Finally, the mixture was heated to 200 °C for 3 h. After drying and pulverizing, the mixture was washed with deionized water and anhydrous ethanol and dried to obtain methylPEEK. (2) 10g of methyl PEEK obtained in step (1), 400ml of o-dichlorobenzene, and 50ml of chlorobenzene were heated to 120°C and stirred for 40min under a nitrogen atmosphere. Then the temperature was raised to 170°C to distill off the chlorobenzene. The mixture was irradiated with 365nm ultraviolet light and the temperature was raised to 160°C. At the same time, 2.5g of liquid bromine was added dropwise over 1h. The mixture was then stirred for 2h under 365nm ultraviolet light irradiation. The mixture was cooled to room temperature and poured into methanol to precipitate and filter. The precipitate was then redissolved in chloroform and filtered. The filtrate was precipitated again in methanol. The precipitate was washed three times with methanol at 65°C and dried to obtain brominated PEEK. (3) Add 10g of PEEK bromide obtained in step (2) and 1g of sodium hydride to 20ml of DMF, add a tetrahydrofuran solution of p-hydroxybenzaldehyde (4g of p-hydroxybenzaldehyde dissolved in 20ml of tetrahydrofuran) at 3℃, continue the reaction for 2.5h, then raise to room temperature and continue the reaction for 2.5h, remove tetrahydrofuran by vacuum distillation, then use dichloromethane and purified water to remove the aqueous phase, wash with saturated sodium chloride solution and 10wt% sodium carbonate solution in sequence, and dry to obtain aldehyde-modified PEEK; (4) Add 10g of aldehyde-modified PEEK obtained in step (3) and 0.1g of sodium persulfate to 100ml of DMF, and then add a DMF solution of 2,3-diaminophenol (2g of 2,3-diaminophenol dissolved in 6ml of DMF). React at room temperature for 43min, then heat to 110℃ and react for 3h. Then stir with dichloromethane and purified water for 30min, remove the aqueous phase, and rotary evaporate to obtain functionalized PEEK resin-1.

[0024] Preparation Example 2 The preparation method of functionalized PEEK resin-2 is the same as that of preparation example 1, except that the amount of liquid bromine added in step (2) is 4g.

[0025] Preparation Example 3 The preparation method of functionalized PEEK resin-3 is the same as that of preparation example 1, except that the amount of p-hydroxybenzaldehyde added in step (3) is 6g.

[0026] Preparation Example 4 The preparation method of functionalized PEEK resin-4 is the same as that of preparation example 1, except that the amount of 2,3-diaminophenol added in step (4) is 3.5g.

[0027] Preparation Example 5 The preparation method of functionalized PEEK resin-5 includes the following steps: (1) 0.3 mol of 4,4-difluorobenzophenone, 0.3 mol of 2,5-dihydroxytoluene, 0.3 mol of hydroquinone, 0.315 mol of sodium carbonate, and 0.315 mol of potassium carbonate were added to 348 ml of sulfolane and 100 ml of toluene. The mixture was heated to 150 °C for 2 h under a nitrogen atmosphere, then heated to 170 °C for 1 h while distilling off the toluene. Finally, the mixture was heated to 200 °C for 3 h. After drying and pulverizing, the mixture was washed with deionized water and anhydrous ethanol and dried to obtain methylPEEK. (2) 10g of methyl PEEK obtained in step (1), 400ml of o-dichlorobenzene, and 50ml of chlorobenzene were heated to 120°C and stirred for 40min under a nitrogen atmosphere. Then the temperature was raised to 170°C to distill off the chlorobenzene. The mixture was irradiated with 365nm ultraviolet light and the temperature was raised to 160°C. At the same time, 2.5g of liquid bromine was added dropwise over 1h. The mixture was then stirred for 2h under 365nm ultraviolet light irradiation. The mixture was cooled to room temperature and poured into methanol to precipitate and filter. The precipitate was then redissolved in chloroform and filtered. The filtrate was precipitated again in methanol. The precipitate was washed three times with methanol at 65°C and dried to obtain brominated PEEK. (3) Add 6g of brominated PEEK obtained in step (2) to 50ml of chloroform, then add 600ml of sulfolane, heat to 150℃, add 100ml of purified water and stir for 4h, then cool to 50℃, add 100ml of DMSO, 2g of sodium dihydrogen phosphate and 2.2g of sodium chlorite and stir for 20h, then add 10ml of 95wt% hydrochloric acid and stir for 4h, add anhydrous methanol to precipitate, filter, wash with anhydrous methanol and then dry to obtain functionalized PEEK resin-5.

[0028] Example 1 A fluorine-free anti-corrosion non-stick coating comprises, by weight, the following raw materials: 50 parts of functionalized PEEK resin-1, 10 parts of hydroxyl-terminated polydimethylsiloxane, 1.3 parts of Pluriol E 1000, 0.3 parts of BYK-024, 0.3 parts of Lutensol XP70, 1.3 parts of BYK-190, 0.08 parts of OP-10, and 35 parts of deionized water.

[0029] The preparation method of the fluorine-free anti-corrosion non-stick coating in this embodiment includes the following steps: S1. Functionalized PEEK resin-1 and Pluriol E 1000 were added to half the weight of deionized water to obtain a PEEK dispersion; hydroxyl-terminated polydimethylsiloxane and OP-10 were added to the remaining deionized water to obtain a PDMS emulsion. S2. Stir the PEEK dispersion obtained in step S1 with PDMS emulsion, BYK-024, Lutensol XP70, and BYK-190 at room temperature for 25 minutes to obtain a coating mixture; S3. The coating mixture obtained in step S2 is applied to the surface of a 304 stainless steel substrate with a coating thickness of 55 μm. After drying at 85°C, it is sintered at a temperature of 350°C for 10 min to obtain the coating.

[0030] Example 2 A fluorine-free anti-corrosion non-stick coating comprises, by weight, the following raw materials: 40 parts of functionalized PEEK resin-1, 5 parts of hydroxyl-terminated polydimethylsiloxane, 0.5 parts of Pluriol E 1000, 0.1 parts of BYK-024, 0.1 parts of Lutensol XP70, 0.5 parts of BYK-190, 0.05 parts of OP-10, and 30 parts of deionized water.

[0031] The preparation method of the fluorine-free anti-corrosion non-stick coating in this embodiment includes the following steps: S1. Functionalized PEEK resin-1 and Pluriol E 1000 were added to half the weight of deionized water to obtain a PEEK dispersion; hydroxyl-terminated polydimethylsiloxane and OP-10 were added to the remaining deionized water to obtain a PDMS emulsion. S2. Stir the PEEK dispersion obtained in step S1 with PDMS emulsion, BYK-024, Lutensol XP70, and BYK-190 at room temperature for 20 minutes to obtain a coating mixture; S3. The coating mixture obtained in step S2 is applied to the surface of a 304 stainless steel substrate with a coating thickness of 55 μm. After drying at 60°C, it is sintered at a temperature of 320°C for 15 min to obtain the coating.

[0032] Example 3 A fluorine-free anti-corrosion non-stick coating comprises, by weight, the following raw materials: 60 parts of functionalized PEEK resin-1, 15 parts of hydroxyl-terminated polydimethylsiloxane, 2 parts of Pluriol E 1000, 0.5 parts of BYK-024, 0.5 parts of Lutensol XP70, 2 parts of BYK-190, 0.1 parts of OP-10, and 40 parts of deionized water.

[0033] The preparation method of the fluorine-free anti-corrosion non-stick coating in this embodiment includes the following steps: S1. Functionalized PEEK resin-1 and Pluriol E 1000 were added to half the weight of deionized water to obtain a PEEK dispersion; hydroxyl-terminated polydimethylsiloxane and OP-10 were added to the remaining deionized water to obtain a PDMS emulsion. S2. Stir the PEEK dispersion obtained in step S1 with PDMS emulsion, BYK-024, Lutensol XP70, and BYK-190 at room temperature for 30 minutes to obtain a coating mixture; S3. The coating mixture obtained in step S2 is applied to the surface of a 304 stainless steel substrate with a coating thickness of 55 μm. After drying at 120°C, it is sintered at a temperature of 380°C for 3 min to obtain the coating.

[0034] Example 4 A fluorine-free anti-corrosion non-stick coating and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that functionalized PEEK resin-1 is replaced by functionalized PEEK resin-2 in an equal amount.

[0035] Example 5 A fluorine-free anti-corrosion non-stick coating and its preparation method are disclosed. The specific implementation method is the same as that in Example 1, except that functionalized PEEK resin-1 is replaced by functionalized PEEK resin-3 in an equal amount.

[0036] Example 6 A fluorine-free anti-corrosion non-stick coating and its preparation method are described. The specific implementation method is the same as in Example 1, except that functionalized PEEK resin-1 is replaced with functionalized PEEK resin-4 in equal amounts.

[0037] Example 7 A fluorine-free anti-corrosion non-stick coating and its preparation method are described. The specific implementation method is the same as in Example 1, except that functionalized PEEK resin-1 is replaced with functionalized PEEK resin-5 in equal amounts.

[0038] Comparative Example 1 A fluorine-free anti-corrosion non-stick coating and its preparation method are described. The specific implementation method is the same as in Example 1, except that functionalized PEEK resin-1 is replaced with an equal amount of PEEK resin.

[0039] Performance testing The coatings obtained in each embodiment were subjected to the following tests: 1. Adhesion: Tested according to the cross-cut adhesion test method of GB / T9286-2021; 2. Non-stickiness: The larger the water contact angle, the stronger the non-stickiness, as determined by the water contact angle test. 3. Heat resistance: Place it in an oven environment of 230℃±3℃ for 100 hours, remove it and cool it for 60 minutes, rinse it with clean water, wipe it clean with non-woven cloth, and observe no obvious abnormalities such as peeling, flaking or discoloration with the naked eye. Test the water contact angle of the coating.

[0040] The test results are shown in Table 1: Table 1 As shown in Table 1, the coatings of Examples 1-3 exhibit good adhesion to the substrate, as well as good non-stickiness and heat resistance. A comparison of the data from Example 4 and Example 1 shows that changing the ratio of methyl PEEK to liquid bromine may lead to excessive bromination, increasing molecular chain rigidity, decreasing solubility, increasing coating brittleness, and disrupting the regularity of the main chain, resulting in decreased adhesion and heat resistance. A comparison of the data from Example 5 and Example 1 shows that changing the ratio of brominated PEEK to p-hydroxybenzaldehyde increases the surface polarity of the coating and decreases non-stickiness. A comparison of Example 6 and Example 1 shows that changing the ratio of aldehyde-modified PEEK to 2,3-diaminophenol may result in amino residue, which is easily decomposed upon heating, increasing coating polarity and decreasing both non-stickiness and heat resistance. A comparison of Example 7 and Example 1 shows that directly using carboxylated PEEK resin decreases the heat resistance of the coating. A comparison of Comparative Example 1 and Example 1 shows that directly using PEEK resin results in a decrease in all properties.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A fluorine-free anti-corrosion and non-stick coating, characterized in that, By weight, it includes the following ingredients: Functionalized PEEK resin 40-60 parts, functionalized PDMS 5-15 parts, surfactant 0.5-2 parts, defoamer 0.1-0.5 parts, leveling agent 0.1-0.5 parts, dispersant 0.5-2 parts, emulsifier 0.05-0.1 parts, solvent 30-40 parts.

2. The fluorine-free anti-corrosion non-stick coating according to claim 1, characterized in that, The method for preparing the functionalized PEEK resin includes the following steps: (1) Add 4,4-difluorobenzophenone, 2,5-dihydroxytoluene, hydroquinone, sodium carbonate, and potassium carbonate to sulfolane and toluene. Under a nitrogen atmosphere, heat to 145-155℃ and react for 1.5-2.5 h. Then heat to 165-175℃ and react for 0.8-1.2 h. Finally heat to 195-205℃ and react for 2.5-3.5 h. After drying and pulverizing, wash and dry to obtain methylPEEK. (2) The methyl PEEK, o-dichlorobenzene and chlorobenzene obtained in step (1) are heated to 115-125℃ and stirred for 30-50 min under a nitrogen atmosphere. Then the temperature is raised to 165-175℃ and irradiated with ultraviolet light. The temperature is then raised to 155-165℃ and liquid bromine is added at the same time. Then the mixture is stirred under ultraviolet light for 1.5-2.5 h and cooled to room temperature. The post-treatment yields brominated PEEK. (3) Add the brominated PEEK and sodium hydride obtained in step (2) to DMF, add a tetrahydrofuran solution of p-hydroxybenzaldehyde at 0-5℃, continue the reaction for 2-3h, then raise the temperature to room temperature and continue the reaction for 2-3h to obtain aldehyde-modified PEEK. (4) Add the aldehyde-modified PEEK and sodium persulfate obtained in step (3) to DMF and then add a DMF solution of 2,3-diaminophenol. React at room temperature for 40-45 min, then heat to 100-120℃ and react for 2.5-3.5 h. After post-treatment, functionalized PEEK resin is obtained.

3. The fluorine-free anti-corrosion non-stick coating according to claim 2, characterized in that, The mass ratio of methyl PEEK to liquid bromine in step (2) is 1:(0.2-0.3).

4. The fluorine-free anti-corrosion non-stick coating according to claim 2, characterized in that, The mass ratio of PEEK bromide to p-hydroxybenzaldehyde in step (3) is 1:(0.3-0.5).

5. The fluorine-free anti-corrosion non-stick coating according to claim 2, characterized in that, The mass ratio of aldehyde-modified PEEK to 2,3-diaminophenol in step (4) is 1:(0.15-0.25).

6. The fluorine-free anti-corrosion non-stick coating according to claim 1, characterized in that, The functionalized PDMS is a hydroxyl-terminated polydimethylsiloxane or an amino-terminated polydimethylsiloxane.

7. The fluorine-free anti-corrosion non-stick coating according to claim 1, characterized in that, The surfactant is a nonionic surfactant.

8. The fluorine-free anti-corrosion non-stick coating according to claim 1, characterized in that, The defoamer is an organosilicone defoamer.

9. A method for preparing a fluorine-free anti-corrosion and non-stick coating according to any one of claims 1-8, characterized in that, Includes the following steps: S1. Functionalized PEEK resin and surfactant are added to part of the solvent to obtain a PEEK dispersion; functionalized PDMS and emulsifier are added to the remaining solvent to obtain a PDMS emulsion; S2. Stir the PEEK dispersion obtained in step S1 with PDMS emulsion, defoamer, leveling agent and dispersant at room temperature for 20-30 minutes to obtain a coating mixture; S3. Apply the coating mixture obtained in step S2 to the surface of the substrate, dry it, and then sinter it to obtain a coating.

10. The method for preparing the fluorine-free anti-corrosion non-stick coating according to claim 9, characterized in that, The drying temperature is 60-120℃, the sintering temperature is 320-380℃, and the time is 3-15 minutes.

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